Anaesthetic Management of Patients with Low Ventricular Ejection Fraction

Abstract

Summary L ow Left Ventricular Ejection Fraction (LVEF) affects a growing percentage of our population. The anesthesiologist must be cognizant of the perioperative considerations of patients undergoing state-of-the-art therapy for low LVEF. Preoperative management includetesting with the use of electrocardiogram, echocardiography and a metabolic panel,continuation of beta blockers, Angiotensin converting enzyme inhibitors and angiotensin receptor blockers, Aldosterone antagonists and Diuretics. Intraoperative management include monitoring by the use of an intraarterialcatheter, central venous catheter, and/or transesophageal echocardiography (which is basedon specific patient needs). Pulmonary artery catheters are rarely used. Choice of a regional or general anesthetic technique is primarily guided by the surgical procedure and patient condition. When either regional anesthesia (including peripheral nerve or neuraxial) or general anesthesia isappropriate, there may be some benefits to regional anesthesia, such as preemptivepostoperativeanalgesia, a decreased risk of pneumonia, and possibly a reduction in 30-day-mortality in patients undergoingsurgery with high cardiac risk. These beneficial effects must be balanced against the potential forhypotension and other patient-specific factors. Modified neuraxial anesthetic techniques (e.g., a low-dosecombined spinal-epiduralwith or without intrathecalopioids, or a very slowly titrated epidural anesthetic) are a reasonable option. A reasonable approach to induction of general anesthesia is the use of a short-actinghypnotic (e.g., etomidate), a moderate dose of anopioid (e.g., fentanyl) and/or lidocaine, and a muscle relaxant with rapid onset. Maintenance of general anesthesia may be achieved with intravenous or volatile anesthetic agents. Doses ofvolatile agents are reduced to avoid significant myocardial depression. Regarding fluid administration, it's aim is to maintain adequate tissue perfusion by optimizing intravascular volumestatus and stroke volume. A continuous infusion of crystalloids may be supplemented with administration ofsmaller-than-usual crystalloid boluses, as needed. Transfusion of red blood cells and other blood components is appropriate for HF patients with borderlinehemoglobin levels (<8 g/dL) who have ongoing bleeding, coagulopathy, or evidence of inadequate perfusion of vital organs. In intraoperative decompensated HF, vasoactive agents are selected based on specific hemodynamic situations. In patients with systemic hypertension or severely symptomatic fluid overload the use of avasodilator (e.g., nitroglycerin) is preferred. In patients with low cardiac output syndrome, an inotropic agent (e.g., milrinone, an inodilator) can be used. In decompensated HF patients with hypotension and evidence of end-organhypoperfusion, an agent with inotropic and vasopressor properties (e.g., norepinephrine) can be used. In cases of severe or refractory vasodilatory shock, the potent direct peripheral vasoconstrictor (i.e., vasopressin) may be necessary. Patients with lowLVEF are more likely to develop postoperative complications (e.g.,pulmonary edema, new or unstable myocardial ischemia, and arrhythmias), therefore early detection and management of these complications is important for better outcome.