Recognition and management of complications during moderate and deep sedation. Part 2: cardiovascular considerations

Abstract

The risk for cardiovascular complications while providing any level of sedation or general anesthesia is greatest when caring for patients already medically compromised. It is reassuring that significant untoward events can generally be prevented by careful preoperative assessment, along with attentive intraoperative monitoring and support. Nevertheless, providers must be prepared to manage untoward events should they arise. This continuing education article will review cardiovascular complications and address their appropriate management.

Figure 1.

Determinants of arterial blood pressure. The first step for improving blood pressure is to increase venous return (preload). When this proves unsuccessful, contractility must be improved. Arterial resistance and heart rate are rarely primary targets, because they produce a greater impact on myocardial oxygen requirements.

Figure 2.

Hypotension algorithm. Hypotensive patients will generally respond to leg elevations or intravenous fluid administration. When drug therapy is indicated, the choice of drug is predicated on heart rate.

Figure 3.

Hypertension algorithm. Episodes of hypertension rarely require treatment. Asymptomatic episodes will generally correct after addressing possible causes. If pressure remains elevated, referral to the primary care physician should be considered. When accompanied by symptoms, emergency medical service transport should be arranged and nitroglycerin or labetalol may be considered.

Figure 4.

Sudden-onset tachycardia algorithm. Current advanced cardiovascular life support guidelines provide several suggestions for managing tachycardias. Although lidocaine is not listed as the preferred agent for ventricular tachycardia, it is nevertheless mentioned as an acceptable alternative. Clinicians will determine the most suitable drugs based on their experience and training. A sinus tachycardia that responds to a beta blocker, such as esmolol, does not necessarily require emergency medical service transport. However, emergency medical service transport should be considered for a sudden onset of all remaining atrial tachydysrhythmias (supraventricular tachycardia, atrial flutter, atrial fibrillation) or ventricular tachycardia, whether or not treatment is performed. While awaiting emergency medical service transport, unstable patients may be managed using antidysrhythmic drugs if cardioversion is not available. Adapted and abridged from the 2010 American Heart Association advanced cardiovascular life support guidelines.

Figure 5.

Chest pain algorithm. It may be difficult to determine whether sudden onset of chest pain is an episode of stable angina or acute coronary syndrome. If the episode was provoked in a patient with a known history of ischemic heart disease and spontaneously subsides or responds to his or her usual dose of nitroglycerin, treatment may be continued and emergency medical support transport is not necessary.

Figure 6.

Office protocol for basic life support. This algorithm summarizes the actions that should be followed when a patient unexpectedly loses consciousness and primary assessment reveals no evidence of breathing. Unlike the American Heart Association guidelines for lay rescuers, health care providers should check for a pulse and provide ventilations along with chest compressions. AED indicates automated external defibrillator; CPR, cardiopulmonary resuscitation; BVM, bag-valve-mask device; EMS, emergency medical service.

Figure 7.

Abridged version of the advanced cardiovascular life support cardiac arrest algorithm. When cardiac arrest is determined, the emergency medical service (911) should be alerted and cardiopulmonary resuscitation commenced immediately as presented in Figure 6. The office team may then follow this abridged version of the 2010 American Heart Association cardiac arrest algorithm. Analysis of the time required for each step in this sequence will reveal that any decision regarding choice of antidysrhythmic drug will likely be unnecessary because the emergency medical service will have arrived.