Case History & Preoperative Assessment PDF

General Surgery Lectures Prof. Dr. Tahrir N. Aldelaimi Lecture: 1 BDS, CDI, MSc, FIBMS, FIAOMS, DLMFS Case History & Preoperative Assessment Surgical procedures and administration of anesthesia are associated with a complex st...

General Surgery Lectures Prof. Dr. Tahrir N. Aldelaimi Lecture: 1 BDS, CDI, MSc, FIBMS, FIAOMS, DLMFS Case History & Preoperative Assessment Surgical procedures and administration of anesthesia are associated with a complex stress response that is proportional to the magnitude of injury, total operating time, amount of intraoperative blood loss and degree of postoperative pain. The adverse metabolic and hemodynamic effects of this stress response can present many problems in the perioperative period. Decreasing the stress response to surgery and trauma is the key factor in improving outcome and lowering the length of hospital stay as well as the total costs of patients care. It is well recognized that safe and efficient surgical and anesthesia practice requires an optimized patient. Several of the large-scale epidemiological studies have indicated that inadequate preoperative preparation of the patient may be a major contributory factor to the primary causes of perioperative mortality. The following primary goals of preoperative evaluation and preparation have been identified: 1. Documentation of the condition(s) for which surgery is needed. 2. Assessment of the patient’s overall health status. 3. Uncovering of hidden conditions that could cause problems both during and after surgery. 4. Perioperative risk determination. 5. Optimization of the patient’s medical condition in order to reduce the patient’s surgical and anesthetic perioperative morbidity or mortality. 6. Development of an appropriate perioperative care plan. 7. Education of the patient about surgery, anesthesia, intraoperative care and postoperative pain treatments in the hope of reducing anxiety and facilitating recovery. 1 General Surgery Lectures Prof. Dr. Tahrir N. Aldelaimi Lecture: 1 BDS, CDI, MSc, FIBMS, FIAOMS, DLMFS 8. Reduction of costs, shortening of hospital stay, reduction of cancellations and increase of patient satisfaction. The ultimate goals of preoperative medical assessment are to reduce the patient’s surgical and anesthetic perioperative morbidity or mortality, and to return him to desirable functioning as quickly as possible. It is imperative to realize that “perioperative” risk is multifactorial and a function of the preoperative medical condition of the patient, the invasiveness of the surgical procedure and the type of anesthetic administered. A history and physical examination, focusing on risk factors for cardiac and pulmonary complications and a determination of the patient’s functional capacity, are essential to any preoperative evaluation. Laboratory investigations should be ordered only when indicated by the patient’s medical status, drug therapy, or the nature of the proposed procedure and not on a routine basis. Persons without concomitant medical problems may need little more than a quick medical review. Those with comorbidity should be optimized for the procedure. Proper consultations with appropriate medical services should be obtained to improve the patient’s health. These consultations should ideally not be done in a “last second” fashion. The preoperative preparation involves procedures that are implemented based on the nature of the expected operation as well as the findings of the diagnostic workup and the preoperative evaluation. General Health Assessment The history The history is the most important component of the preoperative evaluation. The history should include a past and current medical history, a surgical history, a family history, a social history (use of tobacco, alcohol and illegal drugs), a history of allergies, current and recent drug therapy, unusual reactions or responses to drugs and any problems or complications ssociated with previous anesthetics. 2 General Surgery Lectures Prof. Dr. Tahrir N. Aldelaimi Lecture: 1 BDS, CDI, MSc, FIBMS, FIAOMS, DLMFS A family history of adverse reactions associated with anesthesia should also be obtained. In children, the history should also include birth history, focusing on risk factors such as prematurity at birth, perinatal complications and congenital chromosomal or anatomic malformations and history of recent infections, particularly upper and lower respiratory tract infections. The history should include a complete review of systems to look for undiagnosed disease or inadequately controlled chronic disease. Diseases of the cardiovascular and respiratory systems are the most relevant in respect of fitness for anesthesia and surgery. Physical examination The physical examination should build on the information gathered during the history. At a minimum, a focused preanesthesia physical examination includes an assessment of the airway, lungs and heart, with documentation of vital signs. Unexpected abnormal findings on the physical examination should be investigated before elective surgery. Laboratory work up It is generally accepted that the clinical history and physical examination represent the best method of screening for the presence of disease. Routine laboratory tests in patients who are essential. A clinician should consider the risk-benefit ratio of any ordered lab test. When studying a healthy population, 5% of patients will have results which fall outside the normal range. Lab tests should be ordered based on information obtained from the history and physical exam, the age of the patient and the complexity of the surgical procedure. 3 General Surgery Lectures Prof. Dr. Tahrir N. Aldelaimi Lecture: 1 BDS, CDI, MSc, FIBMS, FIAOMS, DLMFS Indications for specific preoperative tests Drug history A history of medication use should be obtained in all patients. Especially, the geriatric population consumes more systemic medications than any other group. Numerous drug interactions and complications arise in this population and special attention should be paid to them. Generally, administration of most drugs should be continued up to and including the morning of operation, although some adjustment in dosage may be required (e.g. antihypertensives, insulin). Some drugs should be discontinued preoperatively. The monoamine oxidase inhibitors should be withdrawn 2-3 weeks before surgery because of the risk of interactions with drugs used during anesthesia. The oral 4 General Surgery Lectures Prof. Dr. Tahrir N. Aldelaimi Lecture: 1 BDS, CDI, MSc, FIBMS, FIAOMS, DLMFS contraceptive pill should be discontinued at least 6 weeks before elective surgery because of the increased risk of venous thrombosis. Recently, the American Society of Anesthesiologists (ASA) examined the use of herbal supplements and the potentially harmful drug interactions that may occur with continued use of these products preoperatively. All patients are requested to discontinue their herbal supplements at least 2 weeks prior to surgery. The use of medications that potentiate bleeding needs to be evaluated closely, with a risk-benefit analysis for each drug and with a recommended time frame for discontinuation based on drug clearance and half life characteristics. Aspirin should be discontinued 7-10 days before surgery to avoid excessive bleeding and thienopyridines (such as clopidogrel) for 2 weeks before surgery. Selective cyclooxygenase-2 (COX-2) inhibitors do not potentiate bleeding and may be continued until surgery. Oral anticoagulants should be stopped 4-5 days prior to invasive procedures, allowing INR to reach a level of 1.5 prior to surgery. Perioperative risk assessment Perioperative risk is a function of the preoperative medical condition of the patient, the invasiveness of the surgical procedure and the type of anesthetic administered. The ASA grading system was introduced originally as a simple description of the physical state of a patient. Despite its apparent simplicity, it remains one of the few prospective descriptions of the patient general health which correlates with the risk of anesthesia and surgery. It is extremely useful and should applied to all patients who present for surgery. Increasing physical status is associated with increasing mortality. 5 General Surgery Lectures Prof. Dr. Tahrir N. Aldelaimi Lecture: 1 BDS, CDI, MSc, FIBMS, FIAOMS, DLMFS American Society of Anesthesiologists’ Classification of Physical Status Surgical complications occur frequently. One large study documented at least one complication in 17% of surgical patients. Surgery-related morbidity and mortality generally fall into one of three categories: cardiac, respiratory and infectious complications. The overall risk for surgery-related complications depends on individual factors and the type of surgical procedure. For example, advanced age places a patient at increased risk for surgical morbidity and mortality. The reason for an age-related increase in surgical complications appears to correlate with an increased likelihood of underlying disease states in older persons. Diseases associated with an increased risk for surgical complications include respiratory and cardiac disease, malnutrition and diabetes mellitus. With respect to the type of surgery, major vascular, intraabdominal and intrathroracic surgical procedures, as well as intracranial neurosurgical procedures are frequently associated with increased perioperative morbidity and mortality19-20. In addition, urgent and emergency procedures constitute higher risk situations than elective, nonurgent surgery and present a limited opportunity for preoperative evaluation and treatment. 6 General Surgery Lectures Prof. Dr. Tahrir N. Aldelaimi Lecture: 1 BDS, CDI, MSc, FIBMS, FIAOMS, DLMFS When one looks at strictly anesthetic problems that lead to morbidity and mortality, airway problems and failure to provide adequate ventilation leading to hypoxia become important. Fortunately the number of critical incidents involving anaesthetics alone appear to be decreasing in recent years. The American College of Cardiology (ACC) and the American Heart Association (AHA) published a task force report on Guidelines for Perioperative Cardiovascular Evaluation for Noncardiac Surgery. The purpose is to provide a framework for considering cardiac risk of noncardiac surgery in a variety of patients and operative situations. The factors which guide decision making include the patient’s cardiovascular risk and functional capacity and the surgery specific risk. Patients’ risk factors are usually subdivided into three categories: Major-risk factors. A 6-week period is necessary for the myocardium to heal after an infarction and for the thrombosis to resolve. Patients with coronary revascularization done within the preceding 40 days should also be classified as high-risk patients. Because of sympathetic stimulation and hypercoagulability during and after surgery, patients with major predictors have a five times greater perioperative risk. Only vital or emergency surgical procedures should therefore be considered for these patients. All elective operations should be postponed and the patients properly investigated and treated. Intermediate-risk factors are proof of well-established but controlled coronary artery disease. Diabetes mellitus is included in this category because it is frequently associated with silent ischemia and represents an independent risk factor for perioperative mortality. Minor risk factors are markers of an increased probability of coronary artery disease, but not of an increased perioperative risk. 7 General Surgery Lectures Prof. Dr. Tahrir N. Aldelaimi Lecture: 1 BDS, CDI, MSc, FIBMS, FIAOMS, DLMFS The decision to proceed with elective surgery begins with an assessment of risk. The clinician should assess the patient’s preoperative risk factors and the risks associated with the planned surgery. It is often helpful to give an estimate of the percentage risk of cardiac complications (see above, by risk class) so that the surgeon can make the most educated decision regarding whether or not to proceed with surgery. The decision to undergo further testing depends upon the interaction of the patient’s risk factors, surgery- specific risk and functional capacity. If a major risk predictor is present, nonemergency surgery should be delayed for medical management, risk factor modification and possible coronary angiography. For patients at intermediate clinical risk, both the exercise tolerance and the extent of the surgery are taken into account with regard to the need for further testing. Patient-Related Predictors for Risk of Perioperative Cardiac Complications 8 General Surgery Lectures Prof. Dr. Tahrir N. Aldelaimi Lecture: 1 BDS, CDI, MSc, FIBMS, FIAOMS, DLMFS Assessment Summary I. History  Respiratory system : smoking,URTI,suppurative lung diseas..etc  CVS: HF,IHD,Dyshythermia,HT…ETC  CNS : neurological & psychological diseases  Abdominal : GIT & Renal  Medical disease: anaemia DM ,endocrine diseases.  Drug allergies  Previous operations & its complications. II. O/E  General examinatione.g vital sigs  Systemic evaluations III. Lab. Investigations e.g. CBP, ESR, RFT, FBS, GUE, Electrolytes (Na, K+, Ca+") Suggestive Reading Norman S William, Roman O Connell, Andrew W McCaskie. Bailey & Love short practice of surgery, 27th edition. Taylor and Francis, 2018 9