From the Guidelines
It is reasonable to restart ACE inhibitors as soon as clinically feasible post-operatively, typically within 24 hours after orthopedic surgery, once the patient is hemodynamically stable and euvolemic. The decision to restart ACE inhibitors should be based on several factors, including blood pressure stability, renal function, and absence of significant postoperative bleeding 1. For most patients, resuming their usual ACE inhibitor dose is appropriate, but consider starting at a lower dose if the patient experienced significant intraoperative hypotension or has borderline blood pressure readings postoperatively. Some key considerations for restarting ACE inhibitors include:
- Blood pressure stability: Ensure the patient's blood pressure is stable and within a normal range before restarting ACE inhibitors.
- Renal function: Monitor renal function and ensure it is stable before restarting ACE inhibitors, as these medications can affect kidney function.
- Absence of significant postoperative bleeding: Ensure the patient is not experiencing significant bleeding before restarting ACE inhibitors, as these medications can increase the risk of bleeding. Monitor blood pressure and renal function after restarting therapy, with measurements at 2-4 hours after the first dose and then daily until stable. The rationale for temporarily withholding ACE inhibitors before surgery is that these medications block the renin-angiotensin-aldosterone system, which impairs compensatory vasoconstriction during anesthesia and can lead to profound hypotension, especially when combined with anesthetic agents 1. Restarting too early may risk hypotension and acute kidney injury, while delaying too long may lead to uncontrolled hypertension, particularly in patients with heart failure or those at high cardiovascular risk.
From the Research
ACE Inhibitors and Surgery
- ACE inhibitors are commonly held prior to surgery to prevent intraoperative hypotension 2, 3, 4
- The decision to restart ACE inhibitors after surgery depends on various factors, including the patient's clinical condition, renal function, and blood pressure stability
Factors to Consider When Restarting ACE Inhibitors
- Renal function: ACE inhibitors should be used with caution in patients with renal impairment, as they can worsen renal function 3, 4
- Blood pressure: ACE inhibitors can cause hypotension, particularly in patients with high renin levels, prior diuretic use, or renal impairment 2, 4
- Concomitant medications: ACE inhibitors can interact with other medications, such as nonsteroid anti-inflammatory agents, which can affect their antihypertensive activity 5
Clinical Considerations
- Patients with stable blood pressure and normal renal function can likely restart ACE inhibitors shortly after surgery 6
- Patients with renal impairment or unstable blood pressure may require closer monitoring and adjustment of their ACE inhibitor dose 3, 4
- The choice of ACE inhibitor and dosage should be individualized based on the patient's clinical condition and response to treatment 2, 3, 6