Antihypertensive Medications in the Perioperative Period_ Managing Blood Pressure Before Surgery

Antihypertensive Medications in the Perioperative Period: Managing Blood Pressure Before Surgery

The management of antihypertensive medications before surgery is a critical aspect of perioperative care that requires careful consideration and planning. Proper blood pressure control is essential for reducing the risk of cardiovascular complications during and after surgery, while also balancing the potential risks associated with abrupt changes in medication regimens.

Hypertension is a common comorbidity among surgical patients, and its management in the perioperative period can significantly impact surgical outcomes. The primary goals of antihypertensive therapy before surgery are to maintain blood pressure stability, prevent extreme fluctuations during the procedure, and reduce the risk of cardiovascular events.

General principles for managing antihypertensive medications before surgery include:

Continuation vs. discontinuation: In most cases, it is recommended to continue the majority of antihypertensive medications up to and including the morning of surgery. Abrupt discontinuation can lead to rebound hypertension and increase the risk of perioperative complications.

Individualized approach: The decision to continue or withhold specific medications should be based on the patient's overall health status, the type of surgery, and the anesthesia plan.

Timing of administration: For medications that are to be continued, they should typically be taken with a small sip of water on the morning of surgery, even if the patient is otherwise NPO (nil per os, or nothing by mouth).

Here's a more detailed look at the management of specific classes of antihypertensive drugs before surgery:

Beta-blockers: Generally, these should be continued perioperatively. They can help control heart rate and reduce the risk of myocardial ischemia. Abrupt discontinuation can lead to rebound tachycardia and hypertension.

ACE inhibitors and ARBs: There is some controversy surrounding these medications. Some guidelines recommend holding them on the morning of surgery due to the potential for intraoperative hypotension, especially with general anesthesia. However, other experts suggest continuing them if the patient has stable renal function and no other contraindications.

Calcium channel blockers: These are usually continued perioperatively, as they can help maintain stable blood pressure during surgery.

Diuretics: The management of diuretics depends on the specific medication and the patient's condition. Loop diuretics are often held on the morning of surgery to avoid dehydration and electrolyte imbalances. Thiazide diuretics may be continued or held, depending on the patient's volume status and electrolyte levels.

Alpha-2 agonists (e.g., clonidine): These should generally be continued, as abrupt discontinuation can lead to rebound hypertension. If the oral route is not available, a transdermal preparation can be considered.

Direct vasodilators (e.g., hydralazine): These are typically continued perioperatively to maintain blood pressure control.

The decision to continue or withhold antihypertensive medications should also take into account the type of surgery and anesthesia:

For patients undergoing major surgery with general anesthesia, there may be a higher risk of intraoperative hypotension, particularly with ACE inhibitors and ARBs.

For minor procedures or those performed under local or regional anesthesia, most antihypertensive medications can usually be continued without significant concerns.

In emergency surgeries, the benefits of continuing antihypertensive medications often outweigh the risks of abrupt discontinuation.