Drugs for the perioperative control of hypertension: current issues and future directions

Clevidipine: a review of its use for managing blood pressure in perioperative and intensive care settings

The ultrashort-acting dihydropyridine calcium channel antagonist clevidipine (Cleviprex(®)) has a rapid onset and offset of effect and reduces blood pressure (BP) by decreasing arteriolar resistance without affecting venous capacitance vessels. This article reviews the clinical efficacy and tolerability of intravenous clevidipine when used to manage BP in perioperative and intensive care settings, as well as summarizing its pharmacological properties. Intravenous clevidipine effectively treated preoperative and postoperative hypertension in patients undergoing cardiac surgery, according to the results of the randomized, multicentre, double-blind, phase III ESCAPE-1 and ESCAPE-2 trials. The randomized, open-label, multicentre, phase III ECLIPSE trials indicated that in terms of keeping systolic BP within the target range, clevidipine was more effective than nitroglycerin or sodium nitroprusside perioperatively and had similar efficacy to nicardipine postoperatively in cardiac surgery patients. In small, double-blind trials in patients undergoing coronary artery bypass graft surgery, perioperative clevidipine was noninferior to nitroglycerin, and postoperative clevidipine had similar efficacy to sodium nitroprusside. Noncomparative studies demonstrated that clevidipine provided rapid BP control in patients with acute neurological injuries (including intracerebral haemorrhage, subarachnoid haemorrhage and acute ischaemic stroke), and was not associated with 'overshoot' in the vast majority of patients. Intravenous clevidipine was generally well tolerated and was usually associated with no reflex tachycardia or only very modest increases in heart rate. In conclusion, intravenous clevidipine is a valuable agent for the management of BP in perioperative and intensive care settings.

Cardiovascular anesthetic complications and treatment in oral surgery

Perioperative hypertension is a common problem. If hypertension is left untreated in patients at risk, infarctions and stroke are possible. There are limited choices of antihypertensive agents for the office. Aggressive antihypertensive therapy is not indicated because most of the episodes seen in the office are hypertensive urgencies and not emergencies. Hypotension is usually managed by decreasing the depth of anesthesia, intravenous fluids, and then vasopressors, typically ephedrine or phenylephrine. Consider treatment of hypotension whenever the mean arterial pressure decreases less than 60 mm Hg.

Perioperative hypertension: defining at-risk patients and their management

Hypertension is an extremely pervasive condition that affects a large percentage of the world population. Although guidelines exist for the treatment of the patient with elevated blood pressure, there remains a paucity of literature and accepted guidelines for the perioperative evaluation and care of the patient with hypertension who undergoes either cardiac or noncardiac surgery. Of particular importance is defining the patients most vulnerable to complications and the indications for immediate and rapid antihypertensive treatment and/or cancellation of surgery to reduce these risks in each of the three perioperative settings: preoperative, intraoperative, and postoperative. This review also examines the parenteral antihypertensive medications most commonly administered in the perioperative setting.

As-Needed Antihypertensive Therapy in Surgical Patients, Why and How: Challenging a Paradigm

Hypertension is common in hospitalized patients and there are many causes. Some patients have no prior history of hypertension, few symptoms, and no apparent morbidity related to acute rises in blood pressure. Though there is no established guideline for therapy in these cases, patients often receive therapy directed at the abnormal vital sign. It is hypothesized that this practice is common and the associated costs are significant. Using the inpatient pharmacy database at the University of Kentucky Chandler Medical Center, a verified Level I trauma center and quaternary referral center, patients on the emergency general surgery or orthopedic surgery services receiving intravenous hydralazine, metoprolol, or labetalol were identified. Subjects were analyzed for indications, parameters, associated history of hypertension, and direct costs. Over the 4-month study period, 114 subjects received 522 drug doses. More than half (55%) of subjects had a prior history of hypertension but only 75 per cent were started on their home medication. Of those without hypertension before admission, 18 per cent required therapy at discharge. Labetalol was the most frequently used agent and total pharmacy costs for this cohort of patients was over $1200. Pro re nata (PRN), short-acting antihypertensive therapy has little evidence base in asymptomatic patients, but its prevalence is high on surgical services. The cost is significant, especially when extrapolated to the larger hospital population at this single institution. Further research is warranted to determine the prevalence of this practice in other centers or national regions, as well as its cost and benefit.

Treatment recommendations to prevent myocardial ischemia and infarction in patients undergoing vascular surgery

During major vascular surgery (MVS), patients are at high risk for developing unrecognized myocardial infarction (MI) and myocardial ischemia. In reducing postoperative morbidity and mortality, preoperative cardiac risk stratification and adequate medical therapy play a pivotal role. Based on literature and current opinions, medical treatment should comprise at least a combination of beta-blockers, aspirin, and statins. beta-Blockers exert their beneficial effects predominantly through heart rate control, leading to reduced oxygen demand during surgery. A heart rate between 65 and 70 bpm should be achieved. Irrespective of their lipid-lowering effects, statins seem to improve postoperative cardiac outcome by stabilizing coronary artery plaques, thereby preventing atherosclerotic plaque rupture. Aspirin reduces platelet activation and vasoconstriction, thereby limiting ischemic events and reducing nonfatal MI by 34%. Adding clopidogrel to low-dose aspirin might be beneficial toward postoperative cardiac outcomes; however, the effect on the incidence of postoperative bleeding complications may be a problem for future studies to resolve. Whereas beta-blockers inhibit the effect of catecholamines, alpha(2)-agonists inhibit catecholamine release and may be used in the perioperative setting when beta-blockers are contraindicated. Despite the blood pressure-lowering effect and anti-inflammatory properties of angiotensin-converting enzyme inhibitors, the literature does not support their use in patients undergoing MVS. The possible use of calcium antagonists before MVS should be further evaluated in high-risk patients with contraindications to beta-blockers, such as asthma, conduction abnormalities, or a history of stroke. Although nitrates are widely used for treating angina pectoris, the beneficial effect of their use in patients undergoing MVS remains controversial. Therefore, nitrates are not routinely used in the perioperative setting. The current American College of Cardiology/American Heart Association guidelines do not recommend prophylactic coronary revascularization before noncardiac surgery in patients with stable coronary artery disease.

Preoperative assessment of high-risk orthopedic surgery patients

A review of guidelines and practice advisories provides the basis of recommendations for the NP to stratify high-risk patients prior to elective orthopedic surgery. A frame of reference for NPs performing preoperative assessment for patients with comorbidity, included cardiac risk and physiologic stratification tools are presented.

Acute kidney injury following cardiac surgery: role of perioperative blood pressure control

BACKGROUND/AIMS

Patients who develop acute kidney injury (AKI) after cardiac surgery continue to have a high mortality rate. Although factors that predispose to postoperative renal dysfunction have been identified, this knowledge has not been associated with a substantial reduction in the incidence of this serious adverse event.

METHODS

This review uses the existing literature to explore the relationship between AKI and perioperative blood pressure (BP) control in cardiac surgery patients. The results of recent novel analyses are introduced, and the implications of these studies for the management of cardiac surgery patients in the perioperative period are discussed.

RESULTS

Preexisting isolated systolic hypertension and wide pulse pressure increase the risk of postoperative renal dysfunction in the cardiac surgery population. New data suggest that BP lability (i.e., BP excursions outside an acceptable physiologic range) during cardiac surgery may also be an important predictor of subsequent renal dysfunction.

CONCLUSION

Recently published data suggest that perioperative BP lability influences both the risk of postoperative renal dysfunction and 30-day mortality. Future studies will determine whether the use of agents that allow improved BP control within a desirable range will reduce the incidence of postoperative AKI in cardiac surgery patients.