Cardiac complications occurring in the postanesthetic care unit (PACU) are typically due to hypotension, hypertension, and dysrhythmias. Patients with known coronary artery disease or congestive heart failure are more prone to these complications after surgical procedure.
Decreased intravascular volume, or hypovolemia is due to inadequate intravenous fluid administration or blood loss. Patients can be resuscitated with crystalloids, colloids, and various blood products. If fluid resuscitation is inadequate to perfuse end organs, then vasopressors and inotropes should be added.
Myocardial ischemia with acute heart failure and ventricular or valvular dysfunction can also lead to hypotension. This may be associated with tachycardia and ST segment changes on electrocardiogram. A history of coronary artery disease predisposes patients to these complications and should be noted on preoperative evaluation. Drug-eluting stents typically require antiplatelet therapy for surgical procedures; if antiplatelet therapy is halted, patients may be at increased risk for acute coronary events. Suspected coronary thrombosis requires immediate evaluation for cardiac catheterization.
Decreased systemic vascular resistance in the PACU setting is usually iatrogenic and leads to hypotension. Disease states that cause decreased SVR include sepsis, spinal shock from spinal cord injury, and histamine release during anaphylactic reactions. While supportive measures are instituted, the underlying cause should be identified and treated. Residual effects of anesthetics, including inhalational, intravenous, and neuraxial agents, also produce hypotension. Treatment is indicated if mean arterial pressure is 20% less than baseline.
Pain is a common cause of hypertension in the PACU. Surgical trauma and pain cause increased sympathetic tone leading to hypertension and tachycardia. Multimodal pain management strategies are preferable.
Hypercarbia from respiratory failure also leads to hypertension. Treatment includes promoting effective gas exchange via invasive or noninvasive, positive pressure ventilation.
Urinary retention and bladder distention are a common cause of hypertension in the PACU. It is more common after inguinal hernia repair, neuraxial anesthesia, and in elderly men with prostatic obstruction. Patients may require bladder catheterization.
Patients who remain intubated in the PACU, if not adequately sedated, may become hypertensive from irritation of the endotracheal tube.
Arrhythmias occur often in the PACU and some can be life-threatening. If cardiac arrest should occur, PACU treatment may have to be tailored to accommodate surgical incisions. Thorough review of current Advanced Cardiac Life Support (ACLS) algorithms should be undertaken.
Bradycardia in the PACU can be due to vasovagal reflexes, residual effects of anticholinesterases, β-blockers, or opioids. Bradycardia may also result from severe myocardial infarction with complete heart block. The ACLS algorithm should be consulted for unstable bradycardia. Anticholinergic medications and pacing options must be readily available.
Sinus tachycardia can result from pain, hypovolemia, fever, sepsis, or certain drugs such as albuterol or anticholinergics.