Preoperative Evaluation and Preparation of the Patient PDF

UNIT IV Preoperative Preparation 20 Preoperative Evaluation and Preparation of the Patient Sarah A. Sheets A crucial element of the perioperative care of the surgical patient on the existing medical condition of the patient, the proposed surgical includes a timely and tho...

UNIT IV Preoperative Preparation 20 Preoperative Evaluation and Preparation of the Patient Sarah A. Sheets A crucial element of the perioperative care of the surgical patient on the existing medical condition of the patient, the proposed surgical includes a timely and thorough preoperative assessment. A fine-tuned procedure, and the type of anesthesia. Significant findings from this approach to patient evaluation then enables appropriate interventions initial evaluation enable the anesthesia provider to make adjustments when required to properly prepare the patient for the upcoming anes- in the patient’s care (i.e., initiate specific treatment modalities to opti- thesia and surgery. For any patient scheduled to undergo anesthesia, mize the patient’s condition for the proposed surgery and anesthesia). preoperative evaluation is compulsory to help identify factors that A thoughtfully executed preoperative history and physical have been increase the risk associated with anesthesia and the status of the patient found to be more predictive of surgical complications than objective relative to the proposed surgery. Essential goals of preoperative assess- preoperative testing.1 ment and preparation of the patient include the following: Important strategies for achieving high-quality, cost-effective Optimize patient care, satisfaction, comfort, and convenience. patient evaluation include the following: Minimize perioperative morbidity and mortality by accurately Educating the practitioner (e.g., regarding the cost of diagnostic assessing factors that influence the risk of anesthesia or might alter tests) and thereby modifying practice patterns the planned anesthetic technique. Developing and implementing evidence-based best practice guide- Minimize surgical delays or preventable cancellations on the day of lines surgery. Using clinical pathways (interdepartmental teamwork required) Determine appropriate postoperative disposition of the patient (i.e., Disseminating information regarding protocols, thereby avoiding given the patient’s status, whether the procedure is best performed duplication of services on an ambulatory, inpatient, or intensive care basis). Performing economic analyses of services, including cost- Evaluate the patient’s overall health status, determining which if any effectiveness and cost-benefit studies preoperative investigations and specialty consultations are required. Rendering efficient resource management Optimize preexisting medical conditions by encouraging requisite Providing for outcomes measurement lifestyle changes (i.e., weight reduction, smoking termination, min- imizing alcohol ingestion, access to ongoing health care monitoring). PREANESTHESIA ASSESSMENT CLINIC Formulate a plan for the most appropriate perianesthetic care and postoperative supportive patient care. The preanesthesia assessment clinic has emerged as the most effective Communicate patient management issues effectively among care means of providing convenient “one-stop shopping” designed to (1) providers. permit patient registration, (2) obtain a medical history and perform a Communicate and provide specific instruction to patients in regard physical examination, (3) promote patient teaching, (4) meet or sched- to preoperative preparation (i.e., fasting and nil per os [NPO] guide- ule appointments with medical consultants, (5) complete any required lines, blood glucose management, home medication administra- preoperative diagnostic testing, and (6) improve regulatory compliance tion). and operating room efficiency. Successful preanesthesia assessment Educate patient regarding surgery, anesthesia, and expected intra- clinics have realized a reduction in patient anxiety, direct cost, last- and postoperative care, including postoperative pain treatments, to minute surgical cancellations, overall length of hospitalization after reduce patient anxiety and increase patient satisfaction. surgery, and diagnostic testing, in addition to improvement in patient Ensure time-efficient and cost-effective patient evaluation. education and a shift from inpatient to outpatient surgery status. The The preoperative visit begins with a thorough review of the patient’s preanesthesia assessment clinic allows patients scheduled for elective medical records and patient interview, followed by the physical exam- surgery to be evaluated and their condition optimized sufficiently in ination. A comprehensive medical history and physical examination advance of the surgery.2 are the cornerstones of a systematic approach to continued patient preparation. Information gathered from this evaluative process guides Timing of Patient Assessment further individualized assessment (e.g., obtaining diagnostic tests, spe- To allow ample time for necessary risk assessment, preoperative testing, cialist consultation). The extent of this preoperative workup depends and specialty consultations, ideal preoperative assessment for surgery 336  CHAPTER 20 Preoperative Evaluation and Preparation of the Patient 337 preexisting medical condition) that may result in surgical delay or can- BOX 20.1 Conditions That Would Benefit cellation. The timing of the preanesthesia assessment does not appear From Early Preoperative Evaluation to influence outcome of anesthesia.4 In one study, no difference in the General cancellation rate for ambulatory patients was observed between groups Medical conditions inhibiting ability to engage in normal daily activity seen within 24 hours and groups seen within 1 to 30 days of the sched- Medical conditions necessitating continual assistance or monitoring at uled surgery.5 Regardless of when performed, this focused evaluation home within the past 6 mo must be performed by a practitioner qualified to administer anesthesia. Admission within the past 2 mo for acute episodes or exacerbation of chronic condition CHART REVIEW Use of medications (e.g., anticoagulants or monoamine oxidase inhibitors) for which modification of schedule or dosage might be required To provide the basis for and direction of the patient interview and physical assessment, the patient’s past and current medical records Cardiocirculatory should be reviewed preoperatively. Ideally the anesthesia provider will History of angina, coronary artery disease, myocardial infarction, symptom- have the opportunity to review the patient’s medical records before the atic arrhythmias interview with the patient or caregiver. History of cardiac rhythm device in case device interrogation or reprogram- ming by appropriate personnel will be necessary Past Medical Records Poorly controlled hypertension (diastolic >110 mm Hg, systolic >160 mm Hg) For a patient who has undergone surgery at the same institution in History of congestive heart failure the past, previous anesthesia records should be retrieved and reviewed, especially if complications are suspected. If past medical records are Respiratory not available, the patient must provide details of significant anes- Asthma or chronic obstructive pulmonary disease that requires chronic thetic experiences. If this information suggests that the patient has an medication; acute exacerbation and progression of these diseases within unusual condition (e.g., atypical plasma cholinesterase, susceptibility the past 6 mo to malignant hyperthermia), surgery may be delayed so that medical History of major airway surgery, unusual airway anatomy, or upper or lower records can be obtained for review to provide further information that airway tumor or obstruction might affect patient care, or measures should be taken (e.g., avoidance History of chronic respiratory distress requiring home ventilatory assistance of succinylcholine, provision of trigger-free anesthetic technique) to or monitoring avoid consequences associated with the condition. Endocrinologic Patient Chart or Electronic Medical Record Diabetes treated with insulin or oral hypoglycemic agents (unable to control A review of the current medical record includes verifying that the sur- with diet alone) gical and anesthesia consents are accurate and complete. The names of Adrenal disorders the patient and surgeon, the date, and the proposed procedure should Active thyroid disease be matched with those on the operating room schedule. Demographic or baseline data, such as the age, height, and weight of the patient, can Hepatic often be obtained from the admitting record. Vital-sign trends and Active hepatobiliary disease or compromise input-output totals are transcribed from graphic flow sheets, which Musculoskeletal may also contain pertinent data (e.g., daily blood glucose values for the Kyphosis or scoliosis causing functional compromise diabetic patient). Temporomandibular joint disorder with restricted mobility Progress notes and consultation reports provide a valuable over- Cervical or thoracic spine injury view of the health history and physical status of the patient. Medical treatments, such as drug dosages and schedules, may be derived from Oncologic these materials, but diagnostic test results should be obtained directly Patients receiving chemotherapy from their original sources. This retrieval of primary data prevents the Other oncological processes with significant physiologic compromise possible misinterpretation of data that were transcribed incorrectly. Knowledge gleaned from a review of progress notes and consultative Gastrointestinal reports enables the anesthesia provider to formulate supplementary Obesity (BMI of 35 or greater) questioning, seek further specialist consultations, or obtain additional Hiatal hernia diagnostic testing as needed. Symptomatic gastroesophageal reflux Baseline data concerning the patient, such as cultural diversity, coping mechanisms, or patient limitations (e.g., hearing impairment), Modified from Barash PG, ed. ASA Refresher Courses in Anesthesiology. Philadelphia: Lippincott Williams & Wilkins; 1996 [vol 24]. can often be derived from nursing notes and can effectively guide the anesthesia provider in conducting a thorough preoperative interview. Increasingly the anesthetist must be able to appropriately interact and anesthesia should take place well in advance of the proposed sur- with culturally diverse populations to properly evaluate and educate gery. Patients with complex medical conditions should be evaluated at patients. least 1 week before the scheduled procedure. Because of present eco- A preanesthesia questionnaire is included on the patient’s chart nomic realities, patients undergoing more complex procedures, and and should be part of the admission paperwork to be completed by those who have complicated medical conditions (see Box 20.1),3 are the patient or the patient’s caregiver and consists of a concise checklist frequently not admitted to the hospital before the day of surgery. Pre- regarding the patient’s health history and medical care. When prop- operative evaluation on the day of surgery can result in last-minute erly completed and readily available on the chart, the preanesthesia discoveries (e.g., of inappropriate fasting, suspected difficult airway, questionnaire enables the anesthesia provider’s visit with the patient 338 UNIT IV Preoperative Preparation to be accomplished more efficiently. Interview questions and physical BOX 20.2 Objectives of the Preoperative assessment are appropriately directed toward abnormal findings and areas of concern. Interview Ensure that the goals of preoperative assessment are met. PATIENT INTERVIEW Provide preoperative education to the patient and family. Obtain written documentation of informed and witnessed consent. The preoperative interview may be conducted in person or by tele- Acquaint the patient and family with the surgical process (to reduce stress phone. The in-person patient interview is preferred, but for patients and increase familiarity). who are unable to visit the hospital setting (e.g., who live far from the Evaluate the patient’s social situation with respect to surgery (e.g., support hospital, have transportation constraints, or because of infectious dis- network). eases such as Covid 19), an opportunity to participate in a telephone Motivate the patient to comply with preventive care strategies (e.g., smok- interview should be made available. Regardless of the location or ing cessation, improvement of cardiovascular fitness). approach used, the interview promotes a trusting relationship between the patient and anesthesia provider. Modified from Cassidy J, Marley RA. Preoperative assessment of the ambulatory patient. J Perianesth Nurs. 1996;11(5):334–343. When the interview is performed in a caring and unhurried man- ner, the patient’s degree of trust and confidence in anesthesia care is enhanced. The manner with which the provider addresses the patient and the family facilitates this trust and confidence in the care they are BOX 20.3 Patient Education Objectives about to receive. In settings where the interview is happening the day of the procedure, the anesthesia provider has a small window of time Promote interactive communication between patient and care provider. to establish this relationship. For example, when the interview occurs Encourage patient participation in making decisions about perioperative in the setting of the hospital preoperative preparation area on the day care. of the procedure, the encounter the anesthesia provider has with the Maximize and enhance patient self-care skills and participation in continu- patient may be only 30 minutes prior to the start of the case. In less ing care during the postoperative phase. desirable circumstances it also may be the first conversation they are Increase the patient’s ability to cope with own health status. having regarding the topic of anesthesia. Increase patient compliance with perioperative care. Thoughtful methods of approach can help the anesthesia provider Provide individualized preoperative instructions regarding the following: efficiently establish an open line of communication with the patient. 1. Where and when laboratory tests, consultations, and diagnostic proce- For instance, patients’ perception of time spent with a provider is dures will be completed greater when the provider sits, rather than stands, during the interview. 2. Appropriate time at which the patient should cease ingestion of food Simply by having the provider sit during the interview, patients report and drink a more positive exchange and more comprehensive understanding of 3. Personal considerations (e.g., comfortable clothes to wear; no jewelry their circumstances.6 or makeup; what personal items to bring; leave valuables at home; bring In the manner of introduction, the anesthesia provider can extend favorite toy, comforter, or book) respect by using the patient’s surname (Mr. Smith, Mrs. Jones) unless 4. Postoperative considerations and instructions (e.g., anticipated recov- instructed differently. The anesthesia provider can introduce oneself ery course, discharge instructions, how to deal with complications) to the patient in this manner: “Hello, I am [name and role of pro- 5. Person to contact if the patient’s physical condition changes (e.g., upper vider]. How would you like to be addressed?”7 During introductions, respiratory tract infection, cancellation) the title of the anesthesia provider and the provider’s specific role in Detail the process of arrival and registration on arrival to the surgical facil- the patient’s perioperative care should also be defined. The patient is ity (i.e., time and location of arrival). entitled to know what role the interviewer plays in the perioperative Review advance directive information as required by law in some states. process. Many times a nurse practitioner or physician assistant may Explain the surgical facility policies to the patient and family. conduct the assessment. The professional appearance and attitude of Modified from Cassidy J, Marley RA. Preoperative assessment of the the anesthesia provider can also create a positive impression during the ambulatory patient. J Perianesth Nurs. 1996;11(5):334–343. preoperative visit. If not done the day of the procedure, the environment of the preopera- tive interview should be staged to maximize the quality and effectiveness caregivers (e.g., family members, legal guardian) for the scheduled sur- of the interaction. Adequate lighting enhances effective communication. gery includes an educational process during which the staff counsels Distractions such as an operating television set or smartphone should be the patient concerning fundamental perioperative issues (Box 20.3).8 mitigated. The interviewer should ensure that the time and location of Reinforcing information to the patient verbally and in writing is essen- the interview are convenient and private for the patient. tial to gaining patient compliance. Coordinating the patient’s visit to Because the preoperative interview is a private interaction between the preanesthesia assessment clinic to include educational time is ideal the patient and the clinician, a tactful request that visitors remain out- for the patient. side the interview area, unless the patient wishes family members to The interview process, along with patient education, yields be present, will be necessary. Otherwise the patient may not volunteer beneficial consequences of reduced patient anxiety and increased confidential health information, such as a history of substance abuse or patient satisfaction. Positive interactions between the patient and sexual history. In certain situations, however, assistance from a family the anesthesia provider have an impact that extends far past the member or caregiver is required. The health history may be provided, perioperative environment. Compliance with perioperative instruc- for example, by the parent of a pediatric patient or by an interpreter for tions increases when the patient is treated with respect. Patient a patient with cognitive or language barriers. satisfaction and compliance with perioperative instructions result The patient interview is designed to achieve specific objectives in decreased length of stay, decreased costs, and overall improved (Box 20.2).8 A valuable step in preparing the patient or responsible clinical outcomes.6  CHAPTER 20 Preoperative Evaluation and Preparation of the Patient 339 Medical History Adverse Drug Effects and Interactions The extent of a patient’s health history depends partly on the amount During the preoperative evaluation, current drug therapy must be care- of information available in the chart before surgery. If the surgeon has fully reviewed for side effects and potential interactions with anesthetic already documented a thorough medical history and physical exam- agents. One drug-management strategy is to discontinue nonessential ination, the interview can focus on confirming major findings and medications preoperatively in the hope of reducing the potential for obtaining information that directly relates to the anesthetic manage- adverse interactions. The therapeutic benefits of these drugs are weighed ment of the patient. The anesthesia provider must obtain and docu- against the risks of abrupt discontinuation. Abrupt discontinuation of ment a detailed health history, however, if the history is unavailable in long-standing medication may lead to the development of undesirable the chart during the preoperative visit. withdrawal symptoms. With occasional exceptions the majority of The health history should be obtained in an organized and system- medications are continued preoperatively. Should a decision be made atic way, as with the preanesthesia questionnaire, to minimize possible to withhold a particular drug before surgery, sufficient time should be omission of important data. Open-ended and direct questions target- allowed for metabolic clearance (ideally 3–5 half-lives).8,9 ing each category of the checklist can be posed. With this approach, more detailed and graded responses are elicited from the patient. To Drug Allergies avoid overwhelming or confusing a patient, questions are asked sepa- A patient’s drug history should include information regarding allergic rately and formulated in comprehensible or layperson’s terms. reactions to certain foods and medications. The most common cause of drug hypersensitivity reactions during anesthesia are neuromuscular Surgical History blocking agents and antibiotics.9 Prior allergic responses are investi- The surgical history of a patient may be learned from the chart or gated so they can be differentiated from adverse drug reactions. Use preoperative interview. Most patients only vaguely recall surgical of certain antibiotics and opioids may be avoided because of gastro- experiences, even from childhood operations. Information regarding intestinal side effects. However, these do not represent a true allergic complications related to previous operations such as a peripheral nerve response. A distinction between allergic reactions and adverse effects injury or uncontrolled blood loss should be elicited to determine the is crucial because an allergy to a drug is an absolute contraindication need for further investigation. to its use. Medications within the same classification of a drug allergy should be avoided, and heightened awareness of a potential allergic Anesthetic History reaction is required during the perioperative period. Past anesthetic experiences are often not as easily defined as the sur- gical history. It is vitally important to determine the reaction of a Latex Sensitivity patient to previously administered anesthetics. Adverse reactions to Patient sensitivity to latex products may be the basis of an allergic reac- anesthetic agents and techniques (e.g., prolonged vomiting, difficult tion. The incidence of intraoperative reaction to latex is on the decline airway, malignant hyperthermia, postoperative delirium, anaphylaxis, secondary to heightened awareness, preventative measures, and man- and cardiopulmonary collapse) may have simply been an annoyance to ufacture of nonlatex hospital supplies. Up to 20% of intraoperative the patient or could have been life threatening. Preoperative knowledge anaphylactic reactions have been attributed to latex sensitivity.10 The of these complications allows the anesthetic approach to be modified preoperative questioning of patients should include inquiry regarding and the recurrence of the complication thereby prevented. Causative specific latex sensitivity or allergy. Patients at increased risk for latex factors are also thoroughly investigated in patients who note that a sensitivity should be cared for in a no-latex setting and scheduled as the previous operation was aborted. Difficulties with airway management first case of the day to reduce the likelihood of aeroallergen latex expo- can alter the approach to endotracheal intubation, if indicated. Vague sure. The diagnosis of latex allergy is based on the findings of the his- reports of fever and convulsions merit further investigation to rule out tory and physical examination and if necessary in vivo (skin-prick test an episode of malignant hyperthermia. is the most sensitive) and in vitro testing. Preoperative testing is indi- cated only when there is a family history of reactions or when patients Familial Anesthetic History report experiencing symptoms such as a rash, swelling, or wheezing Numerous inherited diseases involving metabolic derangements may when exposed to latex. Patients at high risk for latex sensitivity include affect a patient’s reaction to stress and certain drugs, including anes- those with a history of the following:11-14 thetic agents. The patient is specifically asked whether any family mem- Chronic exposure to latex-based products (e.g., industrial workers ber ever experienced an adverse reaction to anesthesia during surgery. using protective gear, occupational exposure to latex) Familial tendencies for diseases such as atypical plasma cholinester- Spina bifida, urologic reconstructive surgery ase, malignant hyperthermia, porphyria, or glycogen storage diseases Repeated surgical procedures (more than nine) (e.g., glucose-6-phosphate dehydrogenase deficiency) are then investi- Intolerance to latex-based products (e.g., balloons, rubber gloves, gated. A diagnosis should be established before the surgery proceeds condoms, dental dams, rubber urethral catheters) because adjustments in the anesthetic management of the patient may Allergy to food and tropical fruits (e.g., avocado, banana, buck- be required. wheat, celery, chestnut, kiwi, mango, papaya, passion fruit, peach) Intraoperative anaphylaxis of uncertain cause Drug History Health care professionals, especially with a history of atopy or A preoperative drug history provides an excellent guide for the direction severe dermatitis, hand eczema and depth of the patient interview and assessment. Drug dosages, sched- ules, and durations of treatment are reviewed and the patient questioned Social History about the purpose and effectiveness of these medications. For example, The addictive nature of tobacco and alcohol, in addition to illegal an interview with a patient receiving β-adrenergic blockers can focus in drugs, exerts a detrimental influence on several aspects of life in the greater detail on the cardiovascular system. Patients on medications for United States. hypertension or angina pectoris require further investigation and possi- Approximately 31.9 million Americans aged 12 years or older bly specialty consultation if they have not been recently evaluated. (11.7%) were classified as illicit drug users in 2021. 340 UNIT IV Preoperative Preparation Nearly one-quarter of all deaths (75,000 annually) in the United from tobacco smoke reduces the deleterious effects of nicotine and car- States are caused by addictive substances. bon monoxide on cardiopulmonary function.23 Smoking cessation for The economic burden of addiction (e.g., health care expendi- even one night before surgery reduces heart rate, blood pressure (BP), tures, missed work, crime) is estimated at more than $400 billion and circulating catecholamine levels and allows carboxyhemoglobin annually. values to return to normal levels.25 Certain drugs, despite their social or recreational application, may Patients who smoke have a higher incidence (a nearly sixfold be associated with adverse and life-threatening consequences with increase) of postoperative pulmonary complications (pneumonia long- or short-term use or overdose. The social history provides an and atelectasis).26 A smoking history of more than 20 pack-years excellent opportunity to explore the extent of self-medication. Open- equates to an increased risk of perioperative complications. Smoking ended questions, posed in a professional and nonjudgmental manner, cessation of less than 4 weeks does not reduce the risk of postopera- are most likely to elicit detailed information from the patient. At this tive respiratory complication.27 Longer periods of smoking cessation time, the patient can also be educated about the adverse consequences (≥8 weeks) result in a marked improvement in pulmonary mechan- of substance abuse, especially as such substances affect anesthetic care.15 ics (e.g., enhanced ciliary function, decreased mucous secretion and small airway obstruction, and enhanced immune function). Patients Smoking who stopped smoking less than 2 months before surgery had nearly Many patients arrive for anesthesia and surgery with a history of smok- four times the pulmonary complications (e.g., purulent sputum, ing either tobacco or electronic cigarettes (e-cigarettes, vapes). In the secretion retention, bronchospasm, pleural effusion, pneumothorax, United States some disturbing statistics are associated with this form of segmental pulmonary collapse, pneumonia) of those who abstained substance abuse:16-22 from smoking for longer than 2 months. However, even short-term One in five deaths in the United States is related to smoking. Ciga- smoking cessation is effective in reducing postoperative compli- rette smoking is the leading cause of preventable premature death cations when compared with patients who continued to smoke up in the United States (approximately 480,000 premature deaths until the time of surgery. A reduction in postoperative wound-related annually). Smokers are 12 to 13 times more likely to die than non- complications occurs in patients who stop smoking preoperatively. smokers. Patients who smoke should be advised to quit, even immediately Cigarette smoking has declined in youth (9.3% in US high schools); prior to surgery, without fear of worsening pulmonary outcomes however, the use of e-cigarettes and hookahs has increased. or increasing psychological stress as a result of acute abstinence. In 2013, use of e-cigarettes among young adults (18–24 years of age) Effective interventions, including behavioral support and nicotine was higher than adults in all age groups.27 replacement therapy, should be made available to smokers consider- As of 2013, 32.5% of e-cigarette users were never or former smokers.27 ing abstinence at this time. Smoking causes nearly 90% of all lung cancer and 80% of all deaths The influence of environmental tobacco smoke (also known as sec- from chronic obstructive pulmonary disease (COPD). ondhand or passive smoke) on children has been found to produce dis- Smoking increases the risk of coronary heart disease and stroke two turbing respiratory consequences, including increased reactive airway to four times. disease, abnormal results of pulmonary function tests, and increased Exposure to secondhand smoke causes 7300 deaths a year from respiratory tract infections.28,29 The perioperative complications in lung cancer and 34,000 deaths from coronary heart disease in adult children exposed to smoke include laryngospasm, coughing on induc- nonsmokers in the United States. tion or emergence, breath holding, postoperative oxyhemoglobin Use of e-cigarettes in and around children has caused an increase desaturation, and hypersecretion.30-36 in poison control center calls from 1 per month in 2010 to 215 per month in 2014. Alcohol Intake Children can suffer from acute nicotine intoxication from exposure Alcohol-attributable deaths equal approximately 95,000 each year, 261 or direct ingestion of e-liquid resulting in seizures, coma, respira- per day, and shorten the lives of those who die by an average of 29 tory arrest, and death. years.37,38 Perioperative complications, such as arrhythmias, infection, The inhaled components of tobacco and e-cigarette smoke lead and alcohol withdrawal syndrome, are increased two- to fivefold in to multiple pathophysiologic changes within the body. Nicotine and chronic excessive alcohol users.39 Postoperative complications can be carbon monoxide are just two of the more than 6000 noxious com- reduced with 4 or more weeks of abstinence prior to surgery.40 Infor- ponents that have been identified in tobacco and e-cigarette smoke.23 mation regarding the type and amount of alcohol regularly consumed Nicotine, a toxic alkaloid, produces ganglionic stimulant effects and is and the frequency of consumption is important in the evaluation for the tobacco component that affects the cardiovascular system.24 The anesthesia and surgery. Often an accurate assessment of a patient’s overall adverse impact tobacco and e-cigarette smoking has on health alcohol intake may be difficult to obtain. The Alcohol Use Disorders is vast (Tables 20.1 and 20.2).19,20 Carbon monoxide readily occupies Identification Test (AUDIT), a self-reporting questionnaire designed the oxygen-binding sites of hemoglobin (approximately 250–300 times to identify problem drinkers, can be incorporated into the preopera- greater affinity for hemoglobin than oxygen).20 Oxygen transport to tive interview of suspected problem drinkers.41 A less confrontational the tissues and resultant oxygen use is thereby drastically reduced. In and a reliable approach to evaluating a patient’s potential for an alcohol the heavy smoker carboxyhemoglobin may be as high as 15%, which problem uses the mnemonic CAGE, which refers to the following four effectively reduces the patient’s oxyhemoglobin percentage accord- questions:42-44 ingly. The adverse effects of nicotine on the cardiovascular system and 1. Do you feel you should cut down on your alcohol consumption? carbon monoxide on oxygen-carrying capacity are short lived (half-life 2. Have people annoyed you by criticizing your drinking habits? of nicotine is 40–60 minutes21; half-life of carbon monoxide if room air 3. Have you felt guilty about your drinking? is breathed is 130–190 minutes).22 Constituents of liquids and aerosols 4. Have you ever had a drink first thing in the morning to steady your in e-cigarettes are noted in Table 20.2. nerves or get rid of a hangover (eye-opener)? Patients should be instructed to stop smoking at least 12 to 48 hours A patient reporting more than two positive responses is at high risk before surgery. Short-term (e.g., 12 hours) preoperative abstinence for alcoholism and an increased likelihood of experiencing withdrawal  CHAPTER 20 Preoperative Evaluation and Preparation of the Patient 341 TABLE 20.1 Effects of Tobacco Smoking System Pathophysiologic Effects Perioperative Effects Respiratory Recurrent cough Laryngospasm and bronchospasm Mucous hypersecretion Sputum retention Mucociliary dysfunction Hypoxemia Loss of integrity of airway epithelium Baro/volutrauma Increased upper and lower airway reactivity Need for reintubation Recurrent chest infections Postoperative atelectasis Loss of elasticity of airways Postoperative chest infection Increased closing volume COPD Cardiovascular Tachycardia Tachycardia Hypertension Hypertension Raised carbon monoxide levels Perioperative risk of myocardial ischemia Reduced oxygen-carrying capacity Venous thromboembolism risk Left shift of oxyhemoglobin dissociation curve Reduced oxygen delivery Increased blood viscosity Atheroma and clot formation Risk of myocardial, cerebral, and peripheral vascular ischemia/infarction Venous thromboembolism risk Hematology Hypercoagulability Risk of perioperative sepsis Increased blood viscosity Risk of perioperative arterial/venous clot formation High white blood cell count Impaired humoral activity and cell-mediated immunity Increased risk of infection Vulnerable to autoimmune diseases Reduced ability to attack malignant cells Wound healing Prolonged wound healing because of long-term immunosuppression and poor Wound breakdown tissue perfusion Perioperative wound infection Bones Reduced bone density and osteoporosis Increased fracture risk Cancer associations Lung Gastrointestinal (esophageal, stomach, liver, pancreas, bowel) Head and neck Genitourinary (bladder, ovarian, cervical) Leukemia COPD, Chronic obstructive pulmonary disease. From Shorrock P, Bakerly N. Effects of smoking on health and anaesthesia. Anaesth Int Care Med. 2015;17:141–143. TABLE 20.2 Constituents of Liquids and Aerosols in E-cigarettes Chemical Description Physiologic Impact Nicotine Common nicotine concentrations are 0–24 mg Sympathomimetic, cardiac, vascular, endocrine, and immunologic toxicity Drug-to-drug interactions Propylene glycol Artificial flavoring Carcinogenic Glycerol Artificial flavoring Cardiotoxic, carcinogenic Diacetyl Artificial flavoring Pulmonary toxicity Acrolein, formaldehyde, and acetaldehyde Toxic compound generated in aerosol Pulmonary and vascular toxicity, carcinogenic Heavy metals Contained in e-liquid and aerosol Pulmonary, vascular, and nephrotoxicity Toluene Volatile compound generated in aerosol Central nervous system depressant symptoms.43 Both AUDIT and CAGE have been shown to be effective delirium tremens as a consequence of alcohol abuse. Clinical signs in identifying the abusive alcohol consumer.44 suggestive of alcohol withdrawal include increased hand tremors, In the heavy drinker, it is important to determine whether the autonomic hyperactivity (e.g., sweating, tachycardia, systolic hyper- patient has experienced seizures, abrupt withdrawal syndrome, or tension), insomnia, anxiety, restlessness, nausea or vomiting, transient 342 UNIT IV Preoperative Preparation hallucinations (visual, tactile, or auditory), psychomotor agitation, and BOX 20.4 Signs and Symptoms of Acute grand mal seizures.43 Chronic alcohol abuse results in the development of tolerance, Substance Abuse physical dependence, and multisystem organ dysfunction. Tolerance Cannabis (Marijuana or Hashish) to alcohol is evidenced by a resistance or cross-tolerance to other cen- Tachycardia, labile blood pressure, headache tral nervous system (CNS) depressants. For example, the anesthetic Euphoria, dysphoria, depression, occasional anxiety and panic reactions, requirement of hypnotics, opioids, and inhalation agents is increased psychosis (rare) in the chronic alcoholic; however, exaggerated responses to anesthetic Poor memory and decreased motivation with chronic use agents are likely during periods of acute intoxication or advanced alco- holism. This effect is attributed to the additive depressant effects of Cocaine and Amphetamines alcohol and anesthetic agents. Enzymatic function and plasma albumin Tachycardia, labile blood pressure, hypertension, myocardial ischemia, concentrations may also be reduced in patients with alcoholic hepatic arrhythmias, pulmonary edema insufficiency. As a result, greater circulating concentrations of unbound Excitement, delirium, hallucinations to psychosis intravenous agents may result in an exaggerated and prolonged drug Euphoria: feeling of excitation, well-being, and enhanced physical strength effect. This enhanced drug response has not been shown to occur with and mental capacity propofol in patients with moderate liver cirrhosis.44,45 Hyperreflexia, tremors, convulsions, mydriasis, sweating, hyperpyrexia, An insidious progression of multisystem organ dysfunction is also exhaustion, coma with overdose characteristic of long-term alcohol abuse. Numerous illnesses are attrib- utable to the toxic adverse effects of advanced alcoholism on overall Hallucinogens: LSD, PCP health and nutrition. Predictably, postoperative morbidity and mortality Sympathomimetic and weak analgesic effects rates are increased in alcoholic patients as a result of poor wound heal- Altered perception and judgment; high doses may progress to toxic psychosis ing, infection, bleeding, pneumonia, and further hepatic deterioration.46 PCP produces dissociative anesthesia with increasing doses Illicit Drug Use Opioids Use of illicit drugs (e.g., cocaine, cannabis, “crack,” lysergic acid Respiratory depression, hypotension, bradycardia, constipation diethylamide-25 [LSD], amphetamines, heroin, hallucinogens, inhal- Euphoria (most marked with heroin) ants, prescription-type psychotherapeutics or opioids used nonmed- Pinpoint pupils with overdose; decreased level of consciousness to coma ically) is a significant health care issue in the United States. The 2016 LSD, Lysergic acid diethylamide-25; PCP, phencyclidine. data from the Centers for Disease Control and Prevention (CDC) From Cheng DCH. The drug addicted patient. Can J Anaesth. have shown continued escalation of prescription opioid use with 1997;44(5 Pt2):R101–R111; Cavaliere F, et al. Anesthesiologic opioid overdose deaths topping all previous estimations.47 The use preoperative evaluation of drug addicted patient. Minerva Anestesiol. of these substances increases the risk for adverse consequences and 2005;71(6):367–371. drug interactions during anesthesia. In addition, patients receiving medically assisted treatment for abstinence of opioids present pain performed. Suspicion of acute substance abuse should be followed management challenges that need to be addressed prior to provision up with a urine screen for drug identification. Abstinence syn- of anesthesia. drome typically exhibits increased sympathetic and parasympathetic An accurate illicit drug history is often difficult to obtain because responses resulting in hypertension, tachycardia, abdominal cramp- of the patient’s fear of legal reprisal or refusal to believe a drug prob- ing and diarrhea, tremors, anxiety, irritability, lacrimation, mydria- lem exists. During the physical examination, the anesthesia provider sis, algid sweat, and yawning.52 should look for signs that indicate illicit drug use by the patient. A A patient-specific pain management plan should be considered diagnosis of recent or continuing drug abuse should be suspected in with patients receiving medically assisted treatment (MAT) for absti- patients exhibiting the following on physical examination:44 nence of opioids. The patient may present with a delineated plan from Evidence of drug injection (e.g., track marks or scarring), throm- their pain management provider indicating current medications and botic veins, phlebitis, tattoos (may be used to mask the sites), suggestions for pain management in the perioperative period. Drug ablation of venous return leading to unilateral edema of the non- therapies for opioid abstinence include antagonists that directly com- dominant hand, subcutaneous skin abscesses pete with opiates typically used in anesthesia. These include metha- Ophthalmologic changes, such as pupillary constriction from opi- done (for opioid de-addiction), suboxone (for maintenance of opioid oid use, pupillary dilation with amphetamine use, nystagmus from abstinence), and naltrexone (for maintenance of abstinence with opi- phencyclidine (PCP) use oids or management of cravings in alcohol abuse). If an opioid-based Lymphadenopathy secondary to nonspecific activation of the anesthetic is planned, the scheduled withdrawal of MAT with opiate immune system as a result of repeated injections of impurities bridging should be considered. In this case, the anesthesia provider Malnourishment as a result of amphetamine abuse (opioid users should be prepared by greater than normal opioid analgesic require- tend to be well nourished) ments, hyperalgesia, and other sequelae related to opioid tolerance.53 Poor dental care and bruxism (involuntary grinding and clenching Often a multimodal pain management plan using a combination of of teeth) from amphetamine use regional anesthesia, local infiltration of the surgical site, with long- Nasal perforation from cocaine abuse acting local anesthetics, ketamine, gabapentin, intravenous lidocaine, Primary concerns for the anesthesia provider are the likeli- clonidine, and/or cyclooxygenase-2 (COX2) inhibitors will allow hood of the patient exhibiting acute abuse or possible withdrawal for the continuation of the patient’s current MAT.54,55 Regardless of syndrome.45 Signs and symptoms of acute abuse of the more com- the anesthetic plan, an empathetic and understanding approach by mon substances are listed in Box 20.4.48-51 Elective surgery should the anesthesia provider can help gain the patient’s trust and prepare be delayed or canceled in patients suspected of being under the the patient to have realistic expectations around perioperative pain influence of an illicit drug until further patient evaluation can be management.  CHAPTER 20 Preoperative Evaluation and Preparation of the Patient 343 Synthetic Androgens herbal therapy, and the dose taken. If patients are in doubt as to the Anabolic steroids are self-administered in an attempt to increase muscle herbal medications they are taking, they should be encouraged to bring mass, strength, and growth, and improve athletic performance, but such the herbal products with them to their preoperative workup. Certain actions can result in hepatic and endocrine system dysfunction. Risks herbal products are known to influence blood clotting, affect blood associated with long-term androgen steroid supplementation include glucose levels, produce CNS stimulation or depression, or interact with impaired liver function, cholestatic jaundice, hepatic adenocarcinoma, psychotropic drugs (Table 20.3).61,62 When practical, discontinuation peliosis hepatis, myocardial infarction (MI), atherosclerosis, hypercoag- of dietary supplements should be encouraged 2 to 3 weeks prior to ulopathy, stroke, hypertension, dyslipidemia, and psychiatric and behav- anesthesia.63 ioral disturbances in susceptible patients.56-60 The hepatotoxic effects have important implications for the anesthetic management of a chronic PATIENT EVALUATION: OVERVIEW OF SYSTEMS steroid abuser, particularly with agents metabolized by the liver, and such patients should undergo preoperative liver function testing. Upper Airway Assessment of the airway should be performed preoperatively in Herbal Dietary Supplements every patient regardless of the plan of anesthetic management. It is Patients should be questioned regarding their use of nonprescription important to evaluate the patient before anesthesia to identify those herbal medications to determine the herb’s name, the duration of patients at risk for difficult airway management (e.g., difficult bag TABLE 20.3 Clinically Important Effects and Perioperative Concerns of Selected Herbal Medicines and Recommendations for Discontinuation of Use Before Surgery Herb: Common Relevant Pharmacologic Preoperative Name(s) Effects Perioperative Concerns Discontinuation Echinacea: purple Activation of cell-mediated immunity Allergic reactions; decreased effectiveness of immunosuppressive No data coneflower root actions of corticosteroids and cyclosporine; potential for immunosuppression with long-term use; inhibition of hepatic microsomal enzymes may precipitate toxicity of drugs metabolized by the liver (e.g., phenytoin, rifampin, phenobarbital) Ephedra: ma huang Increased heart rate and blood Risk of myocardial ischemia and stroke from tachycardia and At least 24 hr before pressure through direct and indirect hypertension; ventricular arrhythmias with halothane; long- surgery sympathomimetic effects term use depletes endogenous catecholamines and may cause intraoperative hemodynamic instability (control hypotension with direct vasoconstrictor, e.g., phenylephrine); life-threatening interaction with monoamine oxidase inhibitors Ginger: Zingiber officinale Food flavoring, upper gastrointestinal Antiplatelet properties; potential to increase risk of bleeding At least 7 days before tract discomfort, nausea, motion surgery sickness, rheumatoid arthritis Garlic: Allium sativum Inhibition of platelet aggregation Potential to increase risk of bleeding, especially when combined At least 7 days before (may be irreversible); increased with other medications that inhibit platelet aggregation surgery fibrinolysis; equivocal antihypertensive activity Ginkgo: duck foot tree, Inhibition of platelet-activating factor Potential to increase risk of bleeding, especially when combined At least 36 hr before maidenhair tree, silver with other medications that inhibit platelet aggregation surgery apricot Ginseng: American ginseng, Lowers blood glucose; inhibition Hypoglycemia; potential to increase risk of bleeding; potential to At least 7 days before Asian ginseng, Chinese of platelet aggregation (may be decrease anticoagulation effect of warfarin surgery ginseng, Korean ginseng irreversible); increased PT-PTT in animals; many other diverse effects Kava: awa, intoxicating Sedation, anxiolysis Potential to increase sedative effect of anesthetics; potential for At least 24 hr before pepper, kawa addiction, tolerance, and withdrawal after abstinence unstudied surgery St John’s wort: amber, goat Inhibition of neurotransmitter Induction of cytochrome P-450 enzymes, affecting cyclosporine, At least 5 days before week, hardhay, Hypericum, reuptake, monoamine oxidase warfarin, steroids, protease inhibitors, and possibly surgery klamatheweed inhibition is unlikely benzodiazepines, calcium channel blockers, and many other drugs; decreased serum digoxin levels Valerian: all heal, garden Sedation Potential to increase sedative effect of anesthetics; No data heliotrope, vandal root benzodiazepine-like acute withdrawal; potential to increase anesthetic requirements with long-term use PT-PTT, Prothrombin time–partial thromboplastin time. Donoghue TJ. Herbal medications and anesthesia case management. AANA J. 2018;86(3):242–248; Kaye AD, et al. Perioperative anesthesia clinical considerations of alternative medicines. Anesthesiol Clin North America. 2004;22:125–139; Chadha RM, Egan BJ. Perioperative considerations of herbal medications. Curr Clin Pharmacol. 2017;12(3):194–200. 344 UNIT IV Preoperative Preparation based on the structures visible on direct examination of the oropharynx TABLE 20.4 Components of the (Fig. 20.1).67 Endotracheal intubation is generally easy in a patient with Preoperative Airway Physical Examination a Mallampati class I airway and can be expected to be difficult in a Airway Examination patient with a Mallampati class III or IV airway. Mallampati airway Component Nonreassuring Findings classification has been criticized as not being a reliable or sensitive Length of upper incisors Relatively long predictor of difficult intubating conditions. Because of the unusually high incidence of false-positive and false-negative findings associated Relation of maxillary and mandibular Prominent “overbite” (maxillary with the system, it should not be used as the only means of screening incisors during normal jaw closure incisors anterior to mandibular for the difficult airway. incisors) Thyromental distance. Thyromental distance can be quantified Relationship of maxillary and Patient cannot bring mandibular to enable prediction of difficulties with laryngoscopy. Thyromental mandibular incisors during incisors anterior to (in front of) distance represents the straight distance, with the neck fully extended voluntary protrusion of the jaw maxillary incisors and the mouth closed, between the prominence of the thyroid cartilage Interincisor distance II) intubation because the pharyngeal and laryngeal axes may not properly Shape of palate Highly arched or very narrow align, and difficult laryngoscopy can be anticipated.68 Compliance of mandibular space Stiff, indurated, occupied by mass, or Interincisor distance. The degree of mouth opening, largely a nonresilient function of the temporomandibular joint, is a vital component of airway assessment. Limited temporomandibular joint movement is a Thyromental distance 5 ft IBW (female) = 100 lb + 5 lb for each inch >5 ft To Calculate Body Mass Index (BMI): Fig. 20.1 Modified Mallampati classification of pharyngeal structures. BMI = Weight in kg/(height in meters)2 Class I, Soft palate, tonsillar fauces, tonsillar pillars, and uvula visualized. Class II, Soft palate, tonsillar fauces, and uvula visualized. Class III, Soft Example 1 palate and base of uvula visualized. Class IV, Soft palate not visualized. 70 kg/1.7 m2 = 70 kg/2.89 m = 24 kg/m2 (From Samsoon GL, Young JR. Difficult tracheal intubation: a retrospec- tive study. Anaesthesia. 1987;42:487–490.) Example 2 125 kg/1.7 m2 = 125 kg/2.89 m = 43 kg/m2 Musculoskeletal System Obesity Evaluation of the musculoskeletal system usually begins with a gen- eral assessment of the size and stature of the patient. Baseline height BOX 20.7 Recommended Diagnostic and weight information can be obtained from the admission data or by Testing of Candidates for Bariatric Surgery direct questioning of the patient during the health history interview. 12-lead electrocardiogram—if at least one risk factor for coronary heart Body weight is then compared with normal values for a given height in disease, poor functional capacity, or both relation to the patient’s age and gender. Ideal body weight, for example, Chest radiograph (posteroanterior and lateral)—if BMI ≥40 kg/m2 can be determined for men and women (Box 20.6). The actual weight Complete blood cell count of the patient is compared with the calculated ideal body weight. Body Glycosylated hemoglobin weight that is 20% in excess of the ideal body weight at a particular Serum chemistries with parameters for liver and kidney function height constitutes obesity. A body weight that is twice the ideal body Fasting blood glucose weight is deemed morbidly obese. Lipid profile (total cholesterol, triglycerides, high-density lipoprotein cho- A more scientific approach to describing weight in relation to lesterol, low-density lipoprotein cholesterol) height uses the measure of body mass index (BMI). Box 20.6 presents Thyroid function (thyrotropin) the formula for calculating BMI and incorporates it into examples for Coagulation studies an average and an overweight individual of the same height. The adult Ferritin patient weight classification based on BMI is as follows: overweight, 25 Vitamins (B12, 25-hydroxyvitamin D, other fat-soluble vitamins if consider- to 29.9 kg/m2; Class 1 obesity, 30 to 34.9 kg/m2; Class 2 obesity, 35 to ing a malabsorptive procedure) 39.9 kg/m2; and Class 3 obesity (sometimes referred to as “severe” obe- Minerals and trace elements (e.g., zinc, selenium, calcium, magnesium) sity), greater than or equal to 40 kg/m2. Two-thirds of the adult popula- tion in the United States are overweight or obese.73 Obese patients are Adapted from Eldar S, et al. A focus on surgical preoperative evaluation at risk of illness from a multitude of pathologic conditions that require of the bariatric patient—the Cleveland Clinic protocol and review of the detailed workup. Anesthesia management of the obese patient is dis- literature. The Surgeon. 2011;9(5):273–277; Poirier P, et al. Cardiovascular cussed in detail in Chapter 48. evaluation and management of severely obese patients undergoing surgery: a science advisory from the American Heart Association. The Class 3 obese patient is at greater risk for cardiopulmonary aber- Circulation. 2009;120(1):86–95; Thompson J, et al. Anesthesia case rations, sleep-disordered breathing, and abnormal airway issues. Preop- management for bariatric surgery, AANA J. 2011;79(2):147–160. erative assessment scheduled in advance of the surgery should reflect careful attention to these concerns.72 Appropriate diagnostic testing prior to bariatric surgery has been proposed (Box 20.7).74,75 Much of this obstruction of the upper airway during sleep.79 More than 70% of testing centers around the likelihood of patients presenting for bariatric patients presenting for bariatric surgery have obstructive sleep apnea.78 surgery with preexisting metabolic complications or nutritional deficien- Particular attention is given to a history of snoring, apneic episodes, cies. The extent of preexisting comorbid medical conditions needs to be frequent arousals during sleep (vocalization, shifting position, extrem- thoroughly evaluated preoperatively, typically by internal medicine phy- ity movements), morning headaches, and daytime somnolence. The sicians. Serious or life-threatening comorbid conditions associated with physical examination would include airway evaluation, nasopha- obesity are noted in Box 20.8.74 Patients should receive cardiac assess- ryngeal characteristics, neck circumference, tonsil size, and tongue ment in accordance with the American Heart Association guidelines.76 volume.80,81 A concise, easy to use screening questionnaire for undi- Asymptomatic patients should be screened for coronary disease if they agnosed obstructive sleep apnea known as STOP-Bang (Box 20.9) has have an abnormal baseline electrocardiogram (ECG), a history of cor- been shown to be highly sensitive for categorizing obstructive sleep onary artery disease/valvular disease, or are more than 50 years of age apnea severity.82 with at least two of the following: metabolic syndrome, diabetes, hyper- Polysomnography is the current gold standard test for establish- tension, smoking, dyslipidemia, or family history of coronary disease.77 ing a clinical diagnosis of obstructive sleep apnea. If the findings of Patients without comorbid conditions may not require further preoper- the history and physical examination are suggestive of obstructive ative workup because diagnostic testing should be individualized based sleep apnea, a decision in consultation with the surgeon should be on identified needs.78 made regarding obtaining a preoperative sleep study. If the diagnosis Obstructive sleep apnea is a breathing disorder, prevalent in the of obstructive sleep apnea is confirmed, the patient will be evaluated obese population, distinguished by periodic, partial, or complete to determine optimal levels of continuous positive airway pressure  CHAPTER 20 Preoperative Evaluation and Preparation of the Patient 347 BOX 20.8 Comorbid Conditions Associated TABLE 20.5 Recommendations for With Obesity Perioperative Glucocorticoid Coverage Known sleep apnea in which patient is noncompliant with continuous pos- Degree of Surgical Stress Recommended Dose itive airway pressure (CPAP) Minor (inguinal hernia repair) Preoperative corticosteroid dose + HbA1C (glycosylated hemoglobin) >8% (average blood sugar >200 mg/dL) hydrocortisone 25 mg or equivalent Diabetic nephropathy, retinopathy, or neuropathy Moderate (lower extremity Preoperative corticosteroid dose + Cirrhosis revascularization, total joint hydrocortisone 50–75 mg or equivalent Pulmonary hypertension replacement) Pseudotumor cerebri (with severe headaches or impending vision loss) Major (cardiac surgery, aortic Preoperative corticosteroid dose + Significant coagulopathy (including history of pulmonary embolus, bleeding aneurysm repair) hydrocortisone* 100–150 mg or diathesis, hypercoagulable syndrome, excessive bleeding, more than one equivalent every 8 hr for 48–72 hr deep venous thrombosis, taking Coumadin or clopidogrel medication) Chronic steroid therapy *Hydrocortisone has mineralocorticoid activity at doses above approx- Oxygen dependent (does not necessarily have to be constant) imately 100 mg/day. The mineralocorticoid activity of hydrocortisone Wheelchair-bound most of the time may produce undesirable side effects, including fluid retention, edema, Systemic disease and poor functional capacity (including multiple sclerosis, and hypokalemia. It is preferable to use a glucocorticoid without miner- inflammatory bowel disease, scleroderma, lupus, cancer) alocorticoid activity, such as methylprednisolone, when the total dose of hydrocortisone exceeds 100 mg/day. Methylprednisolone 4 mg is Severe venous stasis ulcers equivalent to hydrocortisone 20 mg. Recent complaint of chest pain (undiagnosed) From Nagelhout J, Elisha S, Waters E. Should I continue or discontinue Adapted from Eldar S, et al. A focus on surgical preoperative that medication? AANA J. 2009;77(1):59–73. evaluation of the bariatric patient—the Cleveland Clinic protocol and review of the literature. The Surgeon. 2011;9(5):273–277. includes a drying agent and proper upper airway anesthesia, should be instituted. BOX 20.9 STOP-Bang Questionnaire for The patient should be questioned about the use of antiobesity drugs Obstructive Sleep Apnea Screening such as amphetamines, nonamphetamine Schedule IV appetite sup- pressants, and antidepressants (e.g., fluoxetine, sertraline).84 STOP 1. Snoring: Do you snore loudly (loud enough to be heard Yes No Ankylosing Spondylitis and Rheumatoid Arthritis through closed doors)? Disorders of the musculoskeletal system include degenerative disk dis- 2. Tired: Do you often feel tired, fatigued, or sleepy during Yes No ease (osteoarthritis), ankylosing spondylitis, and rheumatoid arthritis daytime? (RA). The chronic pain and inflammation of spinal or extraspinal joints 3. Observed: Has anyone observed you stop breathing during Yes No associated with these diseases limit the degree of patient mobility. Tol- your sleep? erance for positions required during surgery and regional anesthesia 4. Blood Pressure: Do you have or are you being treated for Yes No techniques should therefore be ascertained preoperatively. Traditional high blood pressure? ankylosing spondylitis multimodal approach of treatments (nonsteroi- Bang dal antiinflammatory drugs [NSAIDs], sulfasalazine, glucocorticoids, BMI: BMI >35 kg/m2? Yes No and local corticosteroid injections), and biologic therapies (tumor Age: Age >50 yr? Yes No necrosis factor-α [TNF-α] antagonists) may be included in pharmaco- Neck circumference: Neck circumference >40 cm? Yes No logic regimens for such patients.84 Gender: Male? Yes No If the dosage and duration of corticosteroid therapy are consider- able in patients with rheumatoid arthritis, perioperative supplementa- High risk of OSA: Yes to ≥3 questions tion also may be necessary to avoid hemodynamic instability. Patients Low risk of OSA: Yes to 4 METs) may proceed for surgery provided patients with cardiac Because of the associated risks of perioperative myocardial ischemia risk factors are properly managed with statin and β-blocker therapy as and infarction in patients undergoing a carotid endarterectomy proce- described later in this section. Good functional capacity (>4 METs) dure, a thorough cardiac evaluation by a cardiologist, including 12-lead may be determined by an affirmative answer to two simple questions: ECG and stress testing, is advised.94 (1) Are you able to walk four blocks without stopping regardless of lim- Information gained from the preoperative evaluation of neurologic iting symptoms? (2) Are you able to climb two flights of stairs without function can enlighten the management of a patient with a CNS or stopping regardless of limiting symptoms?101 The inability to climb two peripheral nervous system disorder. For example, sedatives are avoided flights of stairs or walk a short distance is indicative of poor functional in patients with intracranial hypertension, especially when an altered capacity and is associated with an increased incidence of postopera- level of consciousness accompanies the hypertension. Affected patients tive cardiac complications in noncardiac surgery.102,103 Patients with 350 UNIT IV Preoperative Preparation BOX 20.11 Surgical Risk Estimates BOX 20.12 Active Cardiac Conditions for Which the Patient Should Undergo High Risk (Cardiac Risk >5%) Aortic surgery Evaluation and Treatment Before Noncardiac Major vascular surgery Surgery Peripheral vascular surgery Unstable Coronary Syndromes Unstable or severe angina Intermediate Risk (Cardiac Risk 1%–5%) Recent myocardial infarction (MI) within 30 days Intraperitoneal Transplant (e.g., renal, liver, pulmonary) Decompensated Heart Failure Carotid Significant Arrhythmias Peripheral arterial angioplasty High-grade atrioventricular block Endovascular aneurysm repair Symptomatic ventricular arrhythmias Head and neck surgery Supraventricular arrhythmias with uncontrolled ventricular rate Major neurologic/orthopedic (e.g., spine, hip) (>100 beats/min at rest) Intrathoracic Symptomatic bradycardia Major urologic Newly recognized ventricular tachycardia Low Risk (Cardiac Risk 40 mm Hg, area 2 mg/dL) From De Hert S, et al. Preoperative evaluation of the adult patient From De Hert S, et al. Preoperative evaluation of the adult patient undergoing noncardiac surgery: guidelines from the European Society undergoing noncardiac surgery: guidelines from the European Society of Anaesthesiology. Eur J Anaesthesiol. 2011;28(10):684–722. of Anaesthesiology. Eur J Anaesthesiol. 2011;28(10):684–722. moderate to poor functional capacity (90.107 Hypertension is the perioperative risk.113 A systolic BP below 180 mm Hg and diastolic BP most common circulatory derangement to affect humans and is a below 110 mm Hg is not an independent risk factor for perioperative major risk factor for coronary artery disease102 and increased periop- cardiovascular complications.77 erative mortality.108 In 2018, nearly 0.5 million deaths in the United The practitioner taking the medical history should focus on identi- States included hypertension as a primary or contributing cause.109 fying comorbid diseases, such as diabetes mellitus, and social risk fac- Increasingly, patients undergoing surgery have stage 2 hypertension tors (i.e., tobacco use, alcohol or caffeine consumption, illicit drug use and accompanying target-organ damage, or uncontrolled stage 3 [especially cocaine or amphetamines]). What medications the patient hypertension (systolic BP >180 mm Hg, diastolic BP >110 mm Hg, or takes to manage hypertension should be established. In general, the both). This problem can be attributed to the lack of or inadequacy of substances used affect the central and peripheral components of the medical treatment, or to patient noncompliance. In such a situation, sympathetic nervous system by altering the synthesis, release, bio- elective surgery may be postponed for further patient assessment and transformation, or end-organ action of norepinephrine. Because the normalization of the preoperative blood pressure.110,111 Consultation circulatory-depressant effects of general anesthesia may be additive, with an internist can be pursued for the medical evaluation and treat- the combination of antihypertensive drugs and anesthetics is of con- ment of the patient with uncontrolled or newly diagnosed hyperten- cern. Complaints of syncope and dizziness also are investigated. These sion. These recommendations are aimed at reducing the occurrence symptoms may be the clinical manifestations of cerebrovascular insuf- of perioperative hemodynamic instability and consequently the inci- ficiency, although a diagnosis of drug-induced orthostatic hypotension dence of myocardial ischemia. Both complications are more likely to should be considered preoperatively. This diagnosis can be confirmed  CHAPTER 20 Preoperative Evaluation and Preparation of the Patient 351 TABLE 20.8 Comparison of the RCRI, the American College of Surgeons NSQIP MICA, and the American College of Surgeons NSQIP Surgical Risk Calculator American College of Surgeons American College of Surgeons RCRI NSQIP MICA NSQIP Surgical Risk Calculator Criteria … Increasing age Age Creatinine ≥2 mg/dL Creatinine >1.5 mg/dL Acute renal failure HF … HF … Partially or completely dependent Functional status functional status Insulin-dependent diabetes mellitus … Diabetes mellitus Intrathoracic, intraabdominal, or Surgery type: Procedure (CPT code) suprainguinal vascular surgery Anorectal Aortic Bariatric Brain Breast Cardiac ENT Foregut/hepatopancreatobiliary Gallbladder/adrenal/appendix/spleen Intestinal Neck Obstetric/gynecologic Orthopedic Other abdomen Peripheral vascular Skin Spine Thoracic Vein Urologic History of cerebrovascular accident … … or TIA … … ASA physical status class … … Wound class … … Ascites … … Systemic sepsis … … Ventilator dependent … … Disseminated cancer … … Steroid use … … Hypertension Ischemic heart disease … Previous cardiac event … … Sex … … Dyspnea … … Smoker … … COPD … … Dialysis … … Acute kidney injury … … BMI … … Emergency case Use outside original cohort Yes No No Sites Most often single-site studies, but Multicenter Multicenter findings consistent in multicenter studies Continued 352 UNIT IV Preoperative Preparation TABLE 20.8 Comparison of the RCRI, the American College of Surgeons NSQIP MICA, and the American College of Surgeons NSQIP Surgical Risk Calculator—cont’d American College of Surgeons American College of Surgeons RCRI NSQIP MICA NSQIP Surgical Risk Calculator Outcome and risk factor Original: research staff, multiple Trained nurses, no prospective cardiac Trained nurses, no prospective cardiac ascertainment subsequent studies using variety of data outcome ascertainment outcome ascertainment collection strategies Calculation method Single point per risk factor Web-based or open-source Web-based calculator (www.riskcalculator. spreadsheet for calculation facs.org (http://www.surgicalriskcalculator.com/ miorcardiacarrest) ASA, American Society of Anesthesiologists; BMI; body mass index; COPD, chronic obstructive pulmonary disease; CPT, Current Procedural Termi- nology; ENT, ear, nose, and throat; HF, heart failure; NSQIP, National Surgical Quality Improvement Program; NSQIP MICA, National Surgical Quality Improvement Program Myocardial Infarction Cardiac Arrest; RCRI, Revised Cardiac Risk Index; TIA, transient ischemic attack. BOX 20.13 Revised Cardiac Risk Index TABLE 20.9 Exercise Tolerance in Metabolic Equivalents (METs) for Various Risk Categories High-risk surgery (aortic, major vascular, peripheral vascular) Activities Ischemic heart disease (previous myocardial infarction; previous positive Estimated Energy result on stress test, use of nitroglycerin; typical angina; ECG Q waves; Expenditure Physical Activity previous PCI or CABG) 1 MET* Poor functional capacity History of compensated previous congestive heart failure (history of heart Self-care; eating, dressing, or using the toilet; failure; previous pulmonary edema; third heart sound; bilateral rales; evi- walking indoors and around the house; walking dence of heart failure on chest radiograph) 1–2 blocks on level ground at 2–3 mph2 History of cerebrovascular disease (previous TIA; previous stroke) Diabetes mellitus (with or without preoperative insulin) 4 METs Good functional capacity Renal insufficiency (creatinine >2.0 mg/dL) Light housework (e.g., dusting, washing dishes); climbing a flight of stairs without stopping, Estimated Rates for Postoperative Major Cardiac or walking up a hill longer than 1–2 blocks; Complications Per Number of Risks walking on level ground at 4 mph; running a short 0 risk factors: 0.4% distance; heavy housework (e.g., scrubbing floors, 1 risk factor: 0.9% moving heavy furniture); moderate recreational 2 risk factors: 7% activities (e.g., golf, dancing, doubles tennis, ≥3 risk factors: 11% throwing a baseball or football) CABG, Coronary artery bypass grafting; ECG, electrocardiogram; PCI, >10 METs Excellent functional capacity percutaneous coronary intervention; TIA, transient ischemic attack. Strenuous sports (e.g., basketball, cross-country From Lee TH, et al. Derivation and prospective validation of a simple skiing [>8 km/hr],3 rope skipping, running, soccer, index for prediction of cardiac risk of major noncardiac surgery. swimming [>3.5 km/hr], weight training) Circulation. 1999;100(10):1043–1049; Freeman WK, Gibbons RJ. Perioperative cardiovascular assessment of patients undergoing *MET is defined as the amount of oxygen consumed while sitting at noncardiac surgery. Mayo Clin Proc. 2009;84(1):79–90. rest and is equal to 3.5 mL oxygen/kg/min. mph, Miles per hour; km/hr, kilometer per hour. Modified from Jetté M, et al. Metabolic equivalents (METS) in exercise testing, exercise prescription, and evaluation of functional capacity. Clin by measuring a significant decrease in the blood pressure as the patient Cardiol. 1990;13(8):555–565; Fleisher LA, et al. 2014 ACC/AHA guideline rises from the supine position. The lack of hemodynamic compensa- on perioperative cardiovascular evaluation and management of patients tory responses that normally accompany positional changes may then undergoing noncardiac surgery. J Am Coll Cardiol. 2014;64:e77–e137. predict their absence during anesthesia and surgery. The physical examination of the patient includes the following:114,115 Extremities: Delayed or absent femoral pulses secondary to aortic Overall appearance: Truncal obesity with purpura and striae sug- coarctation; evidence of atherosclerosis, peripheral edema gestive of Cushing disease Neurologic evaluation: See “Neurologic System” earlier. Vital signs: Measurement of blood pressure in both arms Funduscopic examination: Hypertensive retinopathy Ischemic Heart Disease Neck: Carotid bruits, distended veins, or enlarged thyroid gland Myocardial ischemia occurs secondary to insufficient oxygen and Heart: Abnormal rhythm or size, murmurs, or heart sounds nutrient supply (increased demand, reduced blood supply, or both) to Lungs: Rales or bronchospa