Preoperative Risk Assessment and Reduction PDF

Preoperative Risk Assessment and Reduction Advanced Health Assessment Key Concepts • Effective preoperative evaluation is based on BOTH history and physical examination • Complete account of all medications • Drug allergies • Reactions to previous anesthetics • ASA is a relative risk assessment t...

Preoperative Risk Assessment and Reduction Advanced Health Assessment Key Concepts • Effective preoperative evaluation is based on BOTH history and physical examination • Complete account of all medications • Drug allergies • Reactions to previous anesthetics • ASA is a relative risk assessment tool • No good data to suggest restricting fluid intake more than 2 hours before induction • To be valuable, testing must discriminate • Premedication is purposeful, not just mindless routine • Patient comorbidities is greatest risk contributor to poor outcomes Preoperative Evaluation • Triggered by the specific patient • Must always include, at a minimum: • Airway exam • Auscultation of heart and lungs • Assessment guides the anesthetic plan • Inadequate preoperative evaluation associated with anesthetic complications • Overall goal is to reduce perioperative morbidity and mortality Purposes of Preoperative Evaluation • Identify those few patients whose outcome will likely be improved by a specific medical treatment • Identify patients whose condition is so poor that surgery might hasten death • Identify patients with specific characteristics that likely will influence the anesthetic plan • Provide patient with estimate of anesthetic risk • Opportunity to describe the proposed plan and obtain informed consent Morbidity and Mortality • Morbidity: unplanned, unwanted, undesirable consequence • Mortality: death • It’s important to know and understand the differences! Consultations • The goal of a consultation • Determine severity of a comorbid condition • Ask if there is treatment necessary to optimize the patient • Help stratify risk • The consultant does not “clear” a patient for anesthesia • Only the anesthesia provider can do this Understanding Risk • Perioperative risk to the patient: • Anesthesia • Surgery • Patient-specific (comorbidities) → greatest contributor to risk • Very difficult to determine anesthesia-specific risk • Estimates of 1 death per 13,000 anesthetics • Clearly, higher-risk patients do worse despite proper evaluation, care, and follow up Contributions to risk Miller’s Anesthesia 9th Ed. Figure 30.1 Anesthesia Risk Over Time (Frequency of Cardiac Arrest per 10,000 Anesthetics) ASA Classification • Physical status assessment tool • Helps to determine overall relative risk • Strongly associated with perioperative risk/outcomes • Many other tools are available • Limitation of the ASA Classification Tool is subjective determination by individual providers • Only about 60% interrater reliability overall ASA Classification ASA I Normal healthy patient ASA II Patient with mild systemic disease (no functional limitations) ASA III Patient with severe systemic disease (some functional limitations) ASA IV Patient with severe systemic disease that is a constant threat to life (functionally incapacitated) ASA V Moribund patient who is not expected to survive without the operation ASA VI Brain-dead patient whose organs are being removed for donor purposes E If the procedure is an emergency, the physical status is followed by “E” (ASA IIIE) ASA Physical Status and Death Rates Risks Related to Patient • Morbidity and mortality are related to coexisting patient disease • It is our job to • • • • • Evaluate the patient Assess for risks Address modifiable risks Explain options Obtain informed consent • We are not responsible for explaining this risks of the procedure Risk Factors and Odds of Dying Within 7 Days Anesthesia-Related Odds of Dying Within 7 Days Surgery Risk (Not Anesthesia Risk) Predictors of 30-Day Mortality The Preoperative Evaluation • How it’s done in reality • Proper preoperative evaluation reduces morbidity and improves outcomes • Multiple guidelines, from multiple organizations, influence our decision-making in the preoperative evaluation process • What is current today is likely not tomorrow • The anesthesia provider makes the decision about anesthesia Importance of Preoperative Evaluation • Australian Incident Monitoring Study (AIMS) • 11% of reports identified inadequate or missing evaluation • 3.1% of all adverse events directly related to poor/missing evaluation • 7 patients died as a result of poor/missing evaluation • 50% of incidents were preventable based on findings of evaluation • Six-fold increase in mortality in patients who were inadequately evaluated Review of Systems v. Physical Examination Goals of Preoperative Assessment 1. Assess medical conditions that may impact perioperative care 2. Manage and improve comorbidities that may impact perioperative care 3. Assess anesthesia risk and lower that risk 4. Identify patients who require special techniques 5. Establish baseline results to aid decision making 6. Educate patients and families 7. Obtain informed consent 8. Facilitate timely care and avoid cancelations 9. Motivate patients to commit to preventative care Timing of Preoperative Evaluation • Need to be convenient for patient and family • Need time to act on findings • Recognize anxiety impairs ability to comprehend and retain information • Potential legal implications related to informed consent • Ideally at least several days prior to planned procedure • Is often seen completed the day of the procedure Preoperative Evaluation Clinics • More than 90% of anesthetics are delivered on an outpatient basis • Most facilities have established some kind of preoperative clinic for anesthesia evaluation • Staffed by RNs functioning by protocols • Each patient is interviewed by the RN (phone or face to face) • Some patients are seen by an anesthesia provider • Patients then present on the day of surgery with a general idea of what to expect – less anxiety and familiar with facility Preoperative Testing • Goal is to obtain information that will improve patient outcome and inform the anesthesia plan • Only 3% of the time do ’routine tests’ impact the patient outcome • Only 6% of the time to ‘specialized tests’ impact the patient outcome • Disease detection is based on the history and physical examination and not on testing with history being useful Medical History • Patients and providers use different words to describe diseases • Thorough histories will assist in planning safe anesthesia • Accuracy goes up • Costs go down • More effective in detecting disease than diagnostic testing (in most cases) Medical History • Start with planned surgery and why • Current and past medical problems • • • • • Severity Stability Exacerbations Prior treatments Planned interventions • Extent, degree of control, and activity limiting nature of medical problems • Medications (Rx and OTC) and allergies • Anesthesia-specific history (patient and family) Physical Exam • Vital signs (including height, weight, and BMI) BMI Classifications Physical Exam • Physical exam of heart & lungs AND airway is absolutely required on EVERY PATIENT • Focused exam on other organ systems as necessary • From patient history • Because of planned surgery • Obtain and previous anesthetic records • Review all diagnostic testing • Review any notes/consultant reports Perioperative Medication Management • Patient specific • In general, continue antihypertensive medications • Hold for 24 hours ACE-I and ARB in some situations • In general, continue inotropic and chronotropic medications • In general, continue exogenous steroids • In general, continue psychiatric medications • In general, continue pain medications • Patient and anesthesia provider specific