Physician's Weekly Article - Managing Perioperative Hypertension

       Perioperative hypertension is associated with high morbidity and mortality in patients undergoing surgery, but using careful management strategies and individualized treatments when necessary can optimize outcomes.

      According to recent estimates, approximately 72 million Americans suffer from hypertension, and the World Health Organization estimates that a third of the global population will have hypertension by 2025. “About 1% to 2% of patients with hypertension will have a ‘hypertensive crisis’ in which they have an acute elevation of blood pressure [BP],” explains Joseph Varon, MD, FACP, FCCP, FCCM. “Many of these cases will occur in the perioperative setting. Despite attempts to standardize approaches to perioperative hypertension, clinicians lack a consensus concerning treatment thresholds and appropriate therapeutic targets.”

      The perioperative period, according to Dr. Varon, is unique with regards to hypertension. “Perioperative hypertension has become remarkably common,” he says. “It’s estimated that about a quarter of people entering the operating room have preexisting hypertension [Table 1]. During surgical procedures, BP can become elevated in several ways. In some cases, it may result from the inappropriate administration of anesthesia. In others, it can occur through pain resulting from the procedure itself or from elevated levels of anxiety that patients may experience. BP levels may also rise postoperatively in cases where long-term antihypertensive medications are discontinued prior to surgery.”

      Identifying Patients at Risk

      Previous investigations have indicated that hypertensive events occur most commonly with carotid surgery, abdominal aortic surgery, peripheral vascular procedures, and intraperitoneal or intrathoracic surgery. Other procedures associated with perioperative hypertension include neurosurgery, transplantations, and surgeries for major trauma or burns. “Perioperative hypertension is more common among patients undergoing cardiac surgery,” Dr. Varon says. “Hypertensive urgencies and emergencies occur in about half of patients during and immediately following cardiac surgery. In addition, any patient who has preexisting hypertension can get perioperative hypertension.”

      When perioperative BPs are elevated or fluctuate considerably, studies have shown that patients are at risk for poor outcomes and/or severe complications, including myocardial ischemia. Some investigations have demonstrated that patients who have chronic hypertension and diastolic BPs of 110 mm Hg or higher are at risk for perioperative cardiac complications. Patients with uncontrolled hypertension undergoing carotid endarterectomy have been shown to experience significantly more postoperative neurologic deficits than those with better control.

      Manage Patients Carefully

      Considering the substantial risks associated with perioperative hypertension, patients must be managed carefully, especially if they have known hypertension (Table 2). “The approach to treating perioperative hypertension is different than that of chronic hypertension,” Dr. Varon explains. “The initial approach to treatment is prevention. Many patients who develop postoperative hypertension do so as a result of their long-term antihypertensive regimens being withdrawn. This withdrawal of therapy should be minimized in the perioperative period.”

      When treatment is necessary, therapy should be individualized for each patient. “The goal is to avoid perioperative BP fluctuations,” says Dr. Varon. “Patients on antihypertensive therapy should maintain compliance to their treatment regimens prior to surgery. This includes the morning of surgery. The only exclusion should be if patients are taking ACE inhibitors and ARBs; that’s because this patient group is at risk for developing hypotension during surgery. However, in most cases, maintaining antihypertensive treatment regimens may contribute to fewer intraoperative BP fluctuations.”

      In general, Dr. Varon says treatment goals should be based on patients’ preoperative BP. “A conservative target would be about 10% to 15% above baseline, but more aggressive approaches to lowering BP may be necessary for patients at very high risk of bleeding or for those with severe heart failure. To optimize safety and efficacy with perioperative hypertension treatments, it’s critical to carefully monitor responses to therapy and adjust therapies appropriately. After surgery, clinicians can safely transition patients to effective oral antihypertensive regimens so that the long-term risks of hypertension and cardiovascular diseases can be managed appropriately.”

      New Therapeutics Emerging

      When selecting agents to control perioperative BP, Dr. Varon says that physicians should consider the clinical situation, patient characteristics, the setting of care, and the experience of the clinicians. “Many IV antihypertensive agents have emerged, providing clinicians with the ability to optimize therapy based on specific needs and conditions. The agents selected should provide an immediate onset of action and have short or intermediate durations of action. They should also be easy to titrate precisely and have strong safety and efficacy profiles for treating perioperative hypertension. Fortunately, newer agents—fenoldopam, nicardipine, and especially clevidipine, for example—have become valuable pharmacological additions. These therapies have been shown to reduce the number and extent of BP fluctuations. The hope is that clinicians will become more familiar with these therapies to help reduce the burden of perioperative hypertension.”

      Joseph Varon, MD, FACP, FCCP, FCCM, has indicated to Physician’s Weekly that he has worked as a consultant and paid speaker for The Medicines Company and EKR Pharmaceuticals. He has also received grants/research aid from The Medicines Company and EKR Pharmaceuticals.