Choosing the Right Anesthesia for Your Patient Fred E. Shapiro, DO Assistant Professor of Anesthesia Department of Anesthesia, Critical Care, and Pain Medicine Kenneth Hughes, M.D. Aesthetic Fellow Division of Plastic and Reconstructive Surgery Beth Israel Deaconess Medical Center Harvard Medical School Patient Workup and Risk Stratification Risks, benefits and alternatives to the administration of sedative and analgesic drugs to establish the level of sedation required Assess risks and comorbidities Anesthesia professionals should be available for morbidly obese patients, pregnant patients, and patients with severe systemic disease, obstructive sleep apnea, or delayed gastric emptying Intraoperative Monitoring Pharmacology of sedative/analgesic drugs, pharmacological antagonists to these drugs, and vasoactive drugs/antiarrhythmics Benefits/risks of supplemental oxygen Recognition of adequacy of ventilatory function and proficiency in advanced airway management Monitoring of physiologic variables, including blood pressure, respiratory rate, and oxygen saturation The Continuum of Sedation Moderate Sedation Deep Sedation General Anesthesia Following Definitions from “Continuum of Depth of Sedation – Definition of General Anesthesia and Levels of Sedation/Analgesia” (Approved by ASA House of Delegates amended October 21, 2009) Moderate Sedation Drug-induced depression of consciousness during which patients respond purposefully to verbal commands No interventions are required to maintain a patent airway Spontaneous ventilation is adequate Deep Sedation Drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully following repeated or painful stimulation Patients may require assistance in maintaining a patent airway Spontaneous ventilation may be inadequate General Anesthesia Drug-induced loss of consciousness during which patients are not arousable, even by painful stimulation The ability to independently maintain ventilatory function is often impaired Often require assistance in maintaining a patent airway Cardiovascular function may be impaired Fast-track anesthesia and monitored anesthesia care (MAC) Fast-track anesthesia involves moving patients through the OR, PACU, and discharge in a relatively short time Short-acting anesthetics and improved pain control are key Local anesthetic with intravenous sedation has become increasingly popular in the office-based plastic surgery community MAC Monitored Anesthesia Care (MAC) MAC is "a specific anesthesia service in which an anesthesiologist has been requested to participate in the care of a patient undergoing a diagnostic or therapeutic procedure" Five Components of Anesthesia 1. Anxiolysis 2. Amnesia 3. Sedation 4. Analgesia 5. Avoidance of side effects (i.e., headache, nausea, vomiting, dizziness, drowsiness, and pain) Seeking the Ideal Anesthetic Rapid onset Rapid recovery Easily controlled depth of sedation Minimal respiratory effect Cardiovascular stability Minimal active metabolic byproducts Local Anesthesia Infiltration within wound or via block or topical Local anesthetic should reduce perioperative opioid Allows patients to remain alert and maintain GI function Local Anesthetic Specifics Local anesthetics of choice in ambulatory anesthesia include lidocaine, bupivacaine, and ropivacaine Lidocaine has a relatively short duration of action Bupivacaine has longer duration of action but a small therapeutic window --- It is associated with profound cardiovascular and central nervous system effects Ropivacaine has a greater safety profile with respect to cardiovascular and CNS toxicity Midazolam Midazolam is a rapid, short-acting benzodiazepine that causes profound anxiolysis, amnesia, and sedation Commonly used as for premedication Minimal cardiovascular depressant effects in doses used for sedation Increasing age reduces requirements Ketamine Causes amnesia and profound analgesia Minimal respiratory effect Stimulates the sympathetic nervous system and can balance the negative cardiovascular effects of propofol Avoid in patients with hypertension, coronary artery disease, congestive heart failure, and increased intracranial pressure High incidence of psychomimetic effects such as restlessness, agitation, and hallucinations Inhaled Anesthetics Desflurane and sevoflurane are well tolerated and achieve a rapid anesthesia and permit rapid emergence Propofol, sevoflurane, and desflurane are similar in recovery endpoints such as home readiness and actual time for discharge From Fredman B, et al. AQ9 Sevoflurane for outpatient anesthesia: A comparison with propofol. Anesth Analg. 1995;81:823–828. AND Raeder J, et al. Recovery characteristics of sevoflurane- or propofolbased anaesthesia for day-care surgery. Acta Anaesthesiol Scand. 1997;41:988–994. Propofol Most widely used intravenous agent for ambulatory anesthesia and sedation Easy to administer, rapid onset, short duration of action, and low incidence of postoperative nausea and vomiting Adverse effects include hypotension and decreased myocardial contractility Common office-based settings include gastroenterology, ophthalmology, and plastic surgery Opioids Can cause respiratory depression Other side effects include nausea, vomiting, and pruritus Fentanyl is the most commonly used opioid Fast onset (3 to 5 minutes) and its duration is 45 to 60 minutes Remifentanil Half-life is 3 to 5 minutes Advantage of short duration is its ability to provide analgesia intraoperatively without postoperative sedation or drowsiness Metabolized by plasma esterase, ideal for patients with kidney or liver disease Disadvantage of its short duration : --- local anesthetic or NSAID must be used for postoperative pain control Nonopioid Analgesics Reduce pain by decreasing the synthesis of prostaglandins Decrease the requirement for opioids and concomitant incidence of nausea, vomiting, and pruritus Ketorolac (Toradol) is a commonly used perioperative NSAID Avoid in those with kidney problems, GI problems, and bleeding issues α2 Agonists Includes clonidine and dexmedetomidine α2 Agonists act in the CNS by decreasing sympathetic nervous system outflow and have sedative, anxiolytic, and analgesic effects Their use decreases the requirement of other anesthetics They help to maintain cardiovascular and respiratory stability Dexmedetomidine Generally well tolerated Particularly safe with respect to respiratory function Very useful for patients undergoing aesthetic facial surgery --- Allows patient to breathe room air spontaneously without use of supplemental oxygen, avoids the issue of combustion Decreases pain medications used postoperatively What makes an ideal agent? To date, no single agent has all these properties Combinations of local anesthetics, midazolam, ketamine, inhaled anesthetics, propofol, opioids, NSAIDS, and α2 agonists can achieve the desired effect Benefits include synergy and decreased potential for side effects POSTOPERATIVE NAUSEA AND VOMITING (PONV) To a large extent, unplanned hospital admission results from uncontrolled pain, nausea, and vomiting Higher risk patients include females, middle-aged patients, nonsmokers, patients with history of motion sickness or PONV Various treatment options could include --- low dose dexamethasone --- transdermal scopolamine --- serotonin antagonists Choosing the Right Anesthesia for Your Patient Thank You