Rapid-acting parenteral antihypertensive agents

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.

Management of perioperative hypertensive urgencies with parenteral medications

BACKGROUND

Hypertension is the major risk factor for cardiovascular (CV) disease such as myocardial infarction (MI) and stroke. This risk is well known to extend into the perioperative period. Although most perioperative hypertension can be managed with the patient's outpatient regimen, there are situations in which oral medications cannot be administered and parenteral medications become necessary. They include postoperative nil per os status, severe pancreatitis, and mechanical ventilation. This article reviews the management of perioperative hypertensive urgency with parenteral medications.

METHODS

A PubMed search was conducted by cross-referencing the terms "perioperative hypertension," "hypertensive urgency," "hypertensive emergency," "parenteral anti-hypertensive," and "medication." The search was limited to English-language articles published between 1970 and 2008. Subsequent PubMed searches were performed to clarify data from the initial search.

RESULTS

As patients with hypertensive urgency are not at great risk for target-organ damage (TOD), continuous infusions that require intensive care unit (ICU) monitoring and intraarterial catheters seem to be unnecessary and a possible misuse of resources.

CONCLUSIONS

When oral therapy cannot be administered, patients with hypertensive urgency can have their blood pressure (BP) reduced with hydralazine, enalaprilat, metoprolol, or labetalol. Due to the scarcity of comparative trials looking at clinically significant outcomes, the medication should be chosen based on comorbidity, efficacy, toxicity, and cost.

Controlling the hemodynamic response to laryngoscopy and endotracheal intubation

The hemodynamic response to the stress of laryngoscopy and endotracheal intubation does not present a problem for most patients. However, patients with cardiovascular or cerebral disease may be at increased risk of morbidity and mortality from the tachycardia and hypertension resulting from this stress. These hemodynamic effects gained notice after the introduction and use of muscle relaxants, such as curare and succinylcholine, for endotracheal intubation at the time of anesthesia induction. A variety of anesthetic techniques and drugs are available to control the hemodynamic response to laryngoscopy and intubation. The method or drug of choice depends on many factors, including the urgency and length of surgery, choice of anesthetic technique, route of administration, medical condition of the patient, and individual preference. The possible solutions number as many as the medications and techniques available and depend on the individual patient and anesthesia care provider. This paper reviews these medications and techniques to guide the clinician in choosing the best methods.

Treating hypertensive emergencies. Controlled reduction of blood pressure and protection of target organs

Diastolic blood pressure of 120 mm Hg or more is often cited as identifying a hypertensive crisis. However, the absolute level of blood pressure may not be as important as the rate of increase. One important feature that distinguishes hypertensive emergency from hypertensive "urgency" is the ongoing vascular damage that occurs with hypertensive emergency. When this is present, therapy should be initiated as soon as possible. The initial goal is to reduce mean arterial pressure about 15% to 25% within the first 48 hours. Overzealous or uncontrolled reduction in blood pressure may result in coma, stroke, myocardial infarction, acute renal failure, or death. Thus, a drug with titratable dosing (eg, intravenous nitroprusside sodium [Nipride, Nitropress]) is preferred in most situations. Patients with hypertensive urgency do not have evidence of vascular damage. Usually, they are asymptomatic, have no retinal lesions, and have a marked elevation in diastolic blood pressure. Hypertensive urgency does not require immediate normalization of blood pressure, but initiation of therapy and careful follow-up are critical.

Clinical implications of autonomic drugs

Drugs that influence autonomic function are used more frequently than surgeons generally imagine. This article summarizes principles of autonomic pharmacology and highlights specific drugs that are useful to the practicing oral and maxillofacial surgeon.