Perioperative medication management: General principles and practical applications
ABSTRACT
An extensive medication history, including the use of nonprescription agents and herbal products, is the foundation of effective perioperative medication management. Decisions about stopping or continuing medications perioperatively should be based on withdrawal potential, the potential for disease progression if therapy is interrupted, the potential for drug interactions with anesthesia, and the patient’s short-term quality of life. In general, medications with withdrawal potential should be continued perioperatively, nonessential medications that increase surgical risk should be discontinued before surgery, and clinical judgment should be exercised in other cases.
KEY POINTS
- Common drugs that have been associated with withdrawal symptoms when discontinued preoperatively include selective serotonin reuptake inhibitors (SSRIs), beta-blockers, clonidine, statins, and corticosteroids.
- In general, most nonsteroidal anti-inflammatory drugs should be stopped at least 3 days before surgery.
- Although ACE inhibitors and angiotensin receptor blockers intensify the hypotensive effects of anesthesia, it may be prudent to continue them perioperatively unless their only indication is for hypertension and the patient’s blood pressure is well controlled.
- Herbal medications should be stopped at least 7 days before surgery, owing to the uncertainly over their actual contents.
- Among psychotropics, SSRIs, tricyclic antidepressants, benzodiazepines, and antipsychotics are generally safe to continue perioperatively.
CASE 1: A PATIENT ON A NONPRESCRIPTION NSAID FOR SEVERE ARTHRITIS
A 55-year-old man with severe osteoarthritis is scheduled for total hip arthroplasy in 2 days. He stopped his aspirin (325 mg/day) 1 week ago but continued taking ibuprofen 600 three times daily with food, explaining that “no one told me to stop.” His last dose was yesterday evening.
Question: What should you do?
A. Call the surgeon and cancel the surgery
B. Call the surgeon to notify, and tell the patient to stop the ibuprofen now
C. Check his bleeding time and proceed if normal
D. Just tell the patient to stop the ibuprofen now
E. Proceed to the operating room regardless of the ibuprofen dose
The best approach would be to notify the surgeon and tell the patient to stop the ibuprofen now. NSAIDs such as ibuprofen reversibly inhibit platelet cyclooxygenase (COX), diminish thromboxane A2 production, diminish platelet aggregation, and can increase bleeding time measurement and overall bleeding risk. They can induce renal failure in combination with other drugs, especially in the setting of hypotension.8,9 COX-2 inhibitors have less effect on platelet function but retain the potential for renal toxicity and also confer well-known cardiovascular risks.
In the past, NSAIDs were typically held for 7 days before surgery, but this practice was not supported with much evidence. In vitro assessment indicates that platelet function normalizes within 24 hours after cessation of regular ibuprofen or dexibuprofen in healthy individuals.10,11
Since NSAIDs vary in their effect on bleeding time, which does not correlate well with elimination half-life, a general recommendation is to stop most NSAIDs at least 3 days before surgery.
CASE 2: A PATIENT ON MULTIPLE CARDIOVASCULAR DRUGS
A 67-year-old man with dilated cardiomyopathy and an ejection fraction of 25% (well compensated) is scheduled for a laparoscopic cholecystectomy tomorrow. He is taking lisinopril (40 mg/day), irbesartan (150 mg/day), and furosemide (80 mg/day).
Question: What is your advice?
A. Call the surgeon and cancel the surgery
B. Call the surgeon to notify, and tell the patient to stop his medications now
C. Hold all of the above medications on the morning of surgery
D. Proceed to the operating room with the usual doses of his medications on the morning of surgery
The best approach is to withhold these medications on the morning of surgery.
Diuretics are typically held on the morning of surgery because of the potential for hypovolemia and electrolyte depletion.
Angiotensin-converting enzyme (ACE) inhibitors intensify the hypotensive effects of anesthesia induction. Because angiotensin II plays a key role in maintaining circulating volume in response to stressors, volume deficits can occur in ACE inhibitor-treated patients as angiotensin II cannot compensate for venous pooling of blood, resulting in diminished cardiac output and arterial hypotension. However, continued renin-angiotensin system suppression may protect regional circulation, as has been demonstrated by reduced release of cardiac enzymes with ACE inhibitor continuation (compared with interruption) in cardiac surgery patients. ACE inhibitors also have a renal protective effect, preserving glomerular filtration rate in patients undergoing aortic abdominal aneurysm repair or coronary artery bypass graft surgery. Hypotension with ACE inhibition is treatable with sympathomimetics, alpha-agonists, and intravenous fluids.12–15
If a patient’s ACE inhibitor is stopped, be prepared for rebound postoperative hypertension. The probability of postoperative atrial fibrillation is also increased with ACE inhibitor interruption.14 In patients with left ventricular dysfunction undergoing noncardiac vascular surgery, continued ACE inhibition is associated with reduced mortality.16 These data argue, at the very least, for prompt resumption of ACE inhibitors after surgery.
Angiotensin receptor blockers (ARBs) have largely the same clinical benefits as do ACE inhibitors. These agents also increase the risk of hypotension upon induction of anesthesia, and this hypotension is not as responsive to conventional vasopressors such as ephedrine and phenylephrine; a better response is achieved with vasopressin.15 In light of the long half-life of ARBs, current thinking is to withhold them 24 hours before surgery.
Rosenman et al recently published a meta-analysis of five studies assessing the effects of continuing or withholding ACE inhibitors and ARBs in the preoperative period.17 They found a statistically significant increase in the incidence of perioperative hypotension in patients in whom the drugs were continued compared with those in whom the drugs were withheld (relative risk = 1.50; 95% CI, 1.15–1.96), but there was no significant difference in the rate of perioperative MI between the two groups. Notably, the indication for ACE inhibitor or ARB use in all of the studies was hypertension, not heart failure.
My approach to the perioperative management of ACE inhibitors and ARBs is to withhold them on the morning of surgery (in the case of ARBs, 24 hours prior to surgery) if their only indication is for hypertension and if the patient’s blood pressure is well controlled. If the patient has another indication for these agents or has hypertension that is not well controlled, I am inclined to continue these agents but will first discuss the decision with the anesthesiologist.
