Page 39 - TNFlipTest

Toronto Notes 2019 Pre-Operative Optimization
◆ discuss perioperative use of ASA, NSAIDs with surgeon (± patient’s cardiologist/internist) ◆ in patients undergoing non-cardiac surgery, starting or continuing low-dose aspirin in the
perioperative period does not appear to protect against post-operative MI or death, but increases the risk of major bleeding
– note: this does not apply to patients with bare metal stents or drug-eluting coronary stents ■ herbal supplements: stop one week prior to elective surgery (ephedra, garlic, ginko, ginseng, kava,
St. John’s Wort, Valerian, Echinacea)
• pre-operativemedicationstoadjust
■ insulin (consider insulin/dextrose infusion or holding dose), prednisone, bronchodilators
Hypertension
• BP <180/110 is not an independent risk factor for perioperative cardiovascular complications
• targetSBP<180mmHg,DBP<110mmHg
• assessforend-organdamageandtreataccordingly
Coronary Artery Disease
• ACC/AHA Guidelines (2014) recommend that at least 60 days should elapse after a MI before a non- cardiac surgery in the absence of a coronary intervention
■ this period carries an increased risk of re-infarction/death
■ if operative procedure is essential and cannot be delayed then invasive intra- and post-operative
ICU monitoring is required to reduce the above risk
• mortality with perioperative MI is 20-50%
• perioperative β-blockers
■ may decrease cardiac events and mortality (but increases risk of perioperative strokes) ■ continue β-blocker if patient is routinely taking it prior to surgery
■ consider initiation of β-blocker in:
◆ patients with CAD or indication for β-blocker
◆ intermediate or high risk surgery, especially vascular surgery
Respiratory Diseases
• smoking
■ adverse effects: altered mucus secretion and clearance, decreased small airway calibre, altered
oxygen carrying capacity, increased airway reactivity and altered immune response
■ abstain at least 8 wk pre-operatively if possible
■ ifunable,abstainingeven24hpre-operativelyhasbeenshowntoincreaseoxygenavailabilitytotissues
• asthma
■ pre-operative management depends on degree of baseline asthma control
■ increasedriskofbronchospasmfromintubation
■ administration of short course (up to 1 wk) pre-operative corticosteroids and inhaled β2-agonists
decreases the risk of bronchospasm and does not increase the risk of infection or delay wound
healing
■ avoid non-selective β-blockers due to risk of bronchospasm (cardioselective β-blockers (metoprolol,
atenolol) do not increase risk in the short-term)
■ delay elective surgery for poorly controlled asthma (increased cough or sputum production, active
wheezing)
■ ideally, delay elective surgery by a minimum of 6 wk if patient develops URTI
• COPD
■ anesthesia, surgery (especially abdominal surgery, in particular upper abdominal surgery) and pain
predispose the patient to atelectasis, bronchospasm, pneumonia, prolonged need for mechanical
ventilation, and respiratory failure
■ pre-operative ABG is needed for all COPD stage II and III patients to assess baseline respiratory
acidosis and plan post-operative management of hypercapnea
■ cancel/delay elective surgery for acute exacerbation
Aspiration
• increasedriskofaspirationwith:
■ decreased LOC (drugs/alcohol, head injury, CNS pathology, trauma/shock)
■ delayed gastric emptying (non-fasted within 8h, diabetes, narcotics)
■ decreased sphincter competence (GERD, hiatus hernia, nasogastric tube, pregnancy, obesity) ■ increased abdominal pressure (pregnancy, obesity, bowel obstruction, acute abdomen)
■ unprotected airway (laryngeal mask vs. ETT)
• management
■ manage risk factors if possible
■ utilize protected airway (i.e., endotracheal tube)
■ reduce gastric volume and acidity
■ delay inhibiting airway reflexes with muscular relaxants
■ employ rapid sequence induction (see Rapid Sequence Induction, A15)
Anesthesia A5
Effects of Extended-Release Metoprolol Succinate in Patients undergoing Non-Cardiac Surgery (POISE Trial): A Randomized Controlled Trial
Lancet 2008;371:1839-1847
Purpose: To investigate the role of β-blockers (metoprolol) perioperatively in patients with known vascular disease undergoing non-cardiac surgery. Methods: Patients from 190 centres in 23 countries were eligible if they were age >45, undergoing non- cardiac surgery, and were known to have significant vascular disease. Patients were randomized to either the metoprolol group or placebo. Participants received metoprolol (or placebo) 100 mg 2-4 h prior to surgery, 6 h after surgery, and then 20 mg daily for 30 d. The primary endpoint was a composite
of cardiovascular death, non-fatal myocardial infarction, and non-fatal cardiac arrest. Analysis was by intention to treat.
Results: 8,351 patients were recruited into the study, with 8,331 completing the 30 d course. Use of metoprolol was found to significantly reduce
the risk of cardiovascular death, non-fatal MI, or non-fatal cardiac arrest vs. placebo (hazard ratio 0.84, p<0.05) but significantly increased the rate of stroke (hazard ratio 2.17, p<0.01) and overall risk of death (hazard ratio 1.33, p<0.05).
Conclusion: Use of perioperative β-blockers (metoprolol) in patients with known vascular disease provides both risks and benefits, and these must be considered for each patient individually.
β-blockers
• β1-receptorsarelocatedprimarilyinthe
heart and kidneys
• β2-receptorsarelocatedinthesmooth
muscle (i.e. bronchi, uterus)
• Non-selective β-blockers block β1 and β2-
receptors (labetalol*, carvedilol, nadolol). Caution is required with non-selective β-blockers, particularly in patients with respiratory conditions where β2 blockade can result in airway reactivity.
*labetalol is both an alpha and beta blocker