What is the appropriate management for a patient in the PACU with new-onset tachycardia and fever?

Management of New-Onset Tachycardia and Fever in PACU

This patient requires immediate assessment for hemodynamic instability and identification of reversible causes, with malignant hyperthermia being the most critical differential given the dramatic heart rate change from 60 to 105 bpm in the immediate postoperative period. 1

Immediate Assessment and Stabilization

Critical first steps:

• Assess for hemodynamic instability: altered mental status, hypotension, signs of shock, or acute heart failure 1, 2
• Attach continuous cardiac monitoring and obtain 12-lead ECG if patient is stable 1, 2
• Establish or verify IV access 1, 2
• Check oxygen saturation and provide supplemental oxygen if needed 1, 2
• Obtain vital signs including blood pressure 1

The dramatic increase in heart rate (from 60 to 105 bpm) is more concerning than the low-grade fever (99.9°F/37.7°C) and suggests a pathologic process rather than simple compensatory tachycardia. 1

Identify Reversible Causes

In the PACU setting, immediately evaluate for:

Life-Threatening Causes

• Malignant hyperthermia: Most critical given the combination of tachycardia and fever in the immediate postoperative period, even with low-grade temperature 3
• Sepsis/infection: Obtain blood cultures and initiate empiric antibiotics if clinically indicated 3
• Hemorrhage/hypovolemia: Check surgical drains, assess for bleeding 3
• Myocardial ischemia: Obtain cardiac enzymes if clinically appropriate 4

Common PACU-Specific Causes

• Pain: Assess pain intensity on agreed scale and treat appropriately 3
• Hypoxia: Verify oxygen saturation and respiratory adequacy 3
• Hypothermia with compensatory response: Although temperature is 99.9°F, verify core temperature with appropriate low-reading thermometer 3
• Electrolyte abnormalities: Check potassium and magnesium levels 4
• Medication effects: Review anesthetic drugs administered 3

Management Algorithm Based on Stability

If Patient is Hemodynamically UNSTABLE:

Do not delay treatment to obtain 12-lead ECG. 1, 2

• Prepare for immediate synchronized cardioversion if tachycardia is causing cardiovascular compromise 1, 2
• Notify anesthesiologist immediately 3
• Consider transfer to ICU 3

If Patient is Hemodynamically STABLE:

Temperature management:

• Patients should not be discharged from PACU if significantly hypothermic, and temperature should be within acceptable limits 3
• However, fever prevention is reasonable as fever after procedures is associated with poor outcomes 3
• Consider antipyretic therapy (acetaminophen 1000 mg IV over 15 minutes for adults ≥50 kg) 5

Tachycardia management:

• Heart rates <150 bpm are unlikely to cause symptoms unless ventricular function is impaired 1
• Sinus tachycardia requires treatment of the underlying cause rather than specific antiarrhythmic therapy 1
• Obtain 12-lead ECG to define rhythm 1, 2
• Assess QRS width (narrow vs. wide complex) 1

Critical Pitfalls to Avoid

Do not normalize heart rate in compensatory tachycardia where cardiac output depends on the rapid rate (e.g., hypovolemia, pain, hypoxia). 1, 2

Do not discharge patient from PACU until:

• Cardiovascular system is stable with no unexplained cardiac irregularity 3
• Pulse and blood pressure approximate normal preoperative values or are at acceptable level 3
• Temperature is within acceptable limits 3
• Pain is adequately controlled 3

Do not attribute all tachycardia to fever alone - the relationship between pulse and fever deviates from expected norms during pharmacological antipyresis, with greater pulse reduction than predicted. 6, 7

Do not use multiple AV nodal blocking agents with overlapping half-lives, which can cause profound bradycardia. 1, 2

Ongoing Monitoring Requirements

Patients must be observed on a one-to-one basis until they have regained airway control, respiratory and cardiovascular stability. 3

Minimum monitoring parameters:

• Heart rate and rhythm 3
• Blood pressure 3
• Oxygen saturation 3
• Core temperature 3
• Level of consciousness 3

The anaesthetist must assess the patient before discharge if there is any doubt about meeting discharge criteria or if problems occurred during recovery. 3