Pre-Operative Optimization Flashcards
In general prior to elective surgery what should be done
■ any fluid and/or electrolyte imbalance should be corrected
■ extent of existing comorbidities should be understood and these conditions should be optimized prior to surgery
■ medications may need adjustment
Pre-operative medications to consider
■ prophylaxis
◆ risk of GE reflux: sodium citrate and/or ranitidine and/or metoclopramide 30 min-1 h prior to surgery
◆ risk of infective endocarditis, GI/GU interventions: antibiotics
◆ risk of adrenal suppression: steroid coverage
◆ anxiety: consider benzodiazepines
◆ COPD, asthma: bronchodilators
◆ CAD risk factors: nitroglycerin and β-blockers
Pre-operative medcations to stop
■ oral antihyperglycemics: stop on morning of surgery
■ ACEI and angiotension receptor blockers: stop the day before the surgery
■ warfarin (consider bridging with heparin), anti-platelet agents (eg. clopidogrel), Xa inhibitor, direct thrombin inhibitors
◆ 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
Pre-operative medications to adjust
■ insulin (consider insulin/dextrose infusion or holding dose), prednisone, bronchodilators
Pre-operative hypertension
- BP <180/110 is not an independent risk factor for perioperative cardiovascular complications
- target SBP <180 mmHg, DBP <110 mmHg
- assess for end-organ damage and treat accordingly
• ACC/AHA Guidelines (2014) recommend that at least how many days should elapse after a MI before a noncardiac surgery in the absence of a coronary intervention
• ACC/AHA Guidelines (2014) recommend that at least 60 days should elapse after a MI before a noncardiac 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%
Role of perioperative beta blockers
■ may decrease cardiac events and mortality (controversial, as recent data suggests stroke risk)
■ 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
Smoking preop
• 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
■ if unable, abstaining even 24 h pre-operatively has been shown to increase oxygen availability to tissues
asthma pre op
■ pre-operative management depends on degree of baseline asthma control
■ increased risk of bronchospasm from intubation
◆ 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 of bronchospasm in the short-term
■ delay elective surgery for poorly controlled asthma (increased cough or sputum production, active wheezing)
■ delay elective surgery by a minimum of 6 wk if patient develops URTI
COPD Pre op
■ 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
Beta 1 and beta 2 receptor locations and non selective beta blocker types and adverse events
- β1-receptors are located primarily in the heart and kidneys
- β2-receptors are located in the lungs
- 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
Aspiration increased risk with
■ decreased LOC
■ trauma
■ meals within 8 h
■ suspected sphincter incompetence (GERD, hiatus hernia, nasogastric tube)
■ increased abdominal pressure (pregnancy, obesity, bowel obstruction, acute abdomen)
■ laryngeal mask vs. endotracheal tube (ETT)
How to prevent aspiration
■ reduce gastric volume and acidity
■ delay inhibiting airway reflexes with muscular relaxants
■ employ rapid sequence induction
Fasting Guidelines Prior to Surgery (Canadian Anesthesiologists’ Society)
- 8 h after a meal that includes meat, fried or fatty foods
- 6 h after a light meal (such as toast or crackers) or after ingestion of infant formula or non-human milk
4 h after ingestion of breast milk
• 2 h after clear fluids (water, black coffee, tea, carbonated beverages, juice without pulp)
Hematological disorders (anemia and coagulopathy management, preop evaluation)
- history of congenital or acquired conditions (sickle cell anemia, factor VIII deficiency, ITP, liver disease)
- evaluate hemoglobin, hematocrit and coagulation profiles when indicated (see Table 1)
• anemia
■ pre-operative treatments to increase hemoglobin (P.O. or I.V. iron supplementation, erythropoietin or pre-admission blood collection in certain populations)
• coagulopathies
■ discontinue or modify anticoagulation therapies (warfarin, clopidogrel, ASA, apixaban, dabigatran) in advance of elective surgeries
■ administration of reversal agents if necessary: vitamin K, FFP, prothrombin complex concentrate, recombinant activated factor VII
