The likelihood of postoperative cardiac complications is influenced by the type of surgery, the patient’s preexisting comorbid state, and perioperative management. Postoperative complications can be general or specific to particular operations and can also be classified according to their time of onset: immediate, early, and late. This chapter will outline a range of common postoperative cardiac complications.

Cardiac complications including nonfatal myocardial infarction (MI), cardiac arrest, and death occur in up to 5% of the patients undergoing noncardiac surgery, and up to 8% in patients undergoing major vascular surgery. Patients who experience an MI after noncardiac surgery have a 15% to 25% in-hospital mortality rate and are at increased risk of cardiovascular death and nonfatal MI during the 6 months following the surgery.

Common cardiac complications in the immediate postoperative period include disorders of blood pressure (hypertension and hypotension), arrhythmias, MI, and cardiac arrest.

I. HYPERTENSION

Hypertension is defined as systolic blood pressure >140 mm Hg or diastolic blood pressure >90 mm Hg. Hypertension in the postanesthesia care unit (PACU) places patients at a higher risk of intensive care unit admission compared to hypotension.

A. Common causes of hypertension in the PACU include:

1. Preexisting hypertension: The most common cause of hypertension in the PACU, especially if the patient did not take his or her morning dose(s) of antihypertensive agent(s)

2. Pain: usually hypertension in association with tachycardia and/or tachypnea

3. Urinary retention and bladder distention: Intraoperative administration of large volumes of intravenous (IV) fluids, history of benign prostatic hyperplasia, inadequate bladder tone because of neuraxial anesthesia, no intraoperative urinary catheter

4. Hypercapnia

5. Hypoxemia

6. Fluid overload: Administration of large volume of IV fluids, intraoperative blood transfusion, and/or large volume of irritation fluid during urologic procedures (prostate surgery)

7. Drug withdrawal (β-blocker, angiotensin-converting enzyme (ACE) inhibitor, opioids, and benzodiazepines)

8. Alcohol withdrawal: Can occur as early as 24 hours after the last alcoholic beverage

9. Anxiety, agitation, or emergence delirium

B. Treatment

1. Administer the patient’s outpatient antihypertensive medications to prevent/treat rebound hypertension.

2. Treat postoperative pain adequately with acetaminophen, nonsteroidal anti-inflammatory drugs (if not contraindicated), and opioids as needed.

3. Measure bladder residual volume and insert urinary catheter if needed.

4. Provide supplemental oxygen via nasal prongs, facemasks, high-flow nasal cannula, constant positive airway pressure (CPAP), or reintubate if needed.

5. In case of hypercapnia, assist ventilation by inserting an oral or a nasopharyngeal airway, start noninvasive ventilation, or reintubate if needed.

6. Administer diuretics in case of fluid overload.

7. Administer benzodiazepines or barbiturates if alcohol withdrawal is suspected.

8. Assess and treat reversible causes of anxiety such as pain, bladder distention, or hypoxemia. Administer IV haloperidol and/or IV physostigmine to treat anxiety, emergence delirium, or agitation.

II. HYPOTENSION

Hypotension in the PACU is caused by decreased preload, decreased cardiac contractility, or decreased vascular tone (decreased systemic vascular resistance).

A. Common causes of hypotension in the PACU include:

1. Hypovolemia secondary to intra- or postoperative hemorrhage, and/or inadequate volume replacement. Check chest tubes, surgical drains, and urinary catheter bags for excessive output.

2. Arrhythmias

3. Myocardial infarction (MI)

4. Pulmonary embolus (PE)

5. Tension pneumothorax

6. Septic or anaphylactic shocks

7. Residual anesthetic effect

8. Neuraxial anesthesia (epidural and spinal)

9. Residual effects of long-acting antihypertensive medications (ACE inhibitors and angiotensin receptor blockers [ARBs])

B. Treatment

1. Treat hypovolemia with a 500 mL IV fluid bolus and assess the patient’s response and repeat this as needed. Avoid excessive volume administration to patients with left- or right-sided heart failure with decreased ejection fraction.

2. For detailed treatment of arrhythmias, please refer to Section III.