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Post-Operative Tachycardia

I. Principles

  • Tachycardia = HR > 100 bpm sustained.
  • Can be a normal physiologic response (pain, fever, hypovolemia) or a sign of serious pathology (bleeding, sepsis, PE, arrhythmia).
  • Always distinguish sinus tachycardia from non-sinus tachyarrhythmia using EKG.
  • Persistent unexplained tachycardia = assume complication until proven otherwise.

II. Sinus vs Non-Sinus Tachycardia

Sinus Tachycardia (most common post-op)

  • P waves present, upright in II, III, aVF.
  • Gradual onset/offset.
  • Etiologies = physiologic stress:
  • Pain, agitation, anxiety
  • Fever, sepsis, SIRS
  • Hypovolemia, hemorrhage, third-spacing
  • Hypoxemia, hypercarbia
  • Anemia
  • Medications (beta-blocker withdrawal, albuterol, pressors)

Non-Sinus Tachycardia (pathologic arrhythmia)

  • Atrial fibrillation/flutter – irregularly irregular, no consistent P waves, rapid ventricular response.
  • SVT (AVNRT, AVRT, atrial tachycardia) – abrupt onset/termination, narrow complex, no visible P waves.
  • Ventricular tachycardia – wide complex, life-threatening.
  • Multifocal atrial tachycardia (MAT) – irregular rhythm with ≥3 P wave morphologies, often in COPD.

III. Differential Diagnosis

Volume / Circulatory

  • Hemorrhage (surgical site, drains, hematoma)
  • Hypovolemia (NPO, inadequate resuscitation, third spacing)
  • Sepsis

Pulmonary

  • Hypoxia, hypercarbia (atelectasis, pneumonia, pulmonary edema)
  • Pulmonary embolism
  • Pneumothorax

Cardiac

  • Myocardial ischemia or infarction
  • Arrhythmia (AFib, SVT, VT, MAT)
  • CHF exacerbation

Other

  • Pain, anxiety, agitation
  • Fever
  • Endocrine (thyrotoxicosis, pheochromocytoma, withdrawal states)
  • Medications (albuterol, pressors, anticholinergics)

IV. Stepwise Evaluation

Step 1 – Confirm

  • Recheck vitals manually.
  • Obtain EKG to distinguish sinus vs arrhythmia.

Step 2 – Assess Stability

  • Hemodynamics: BP, mentation, urine output.
  • Oxygenation and ventilation.
  • If unstable: ACLS, call senior/ICU, resuscitate.

Step 3 – Focused History & Exam

  • Chest pain, dyspnea, palpitations, bleeding, abdominal pain.
  • Inspect wounds, drains, dressings for hemorrhage.
  • Examine chest, lungs, extremities.

Step 4 – Workup

  • Continuous telemetry, EKG.
  • CBC (hemoglobin/hematocrit), BMP (lytes).
  • Troponin if chest pain or ischemia concern.
  • Lactate and cultures if febrile or septic features.
  • CXR (pneumonia, effusion, pneumothorax).
  • CT chest (PE protocol) if hypoxia or unexplained tachycardia with risk factors.

V. Management

Sinus Tachycardia (secondary to physiologic stress)

  • Treat underlying cause:
  • Pain → multimodal analgesia.
  • Fever/sepsis → cultures, antibiotics, source control.
  • Hypovolemia/hemorrhage → IV fluids, blood products.
  • Hypoxia → O2, pulmonary toilet, bronchodilators.
  • Anemia → transfusion if indicated.

Non-Sinus Tachycardia (primary arrhythmia)

  • Atrial fibrillation/flutter with RVR
  • Stable: metoprolol 5 mg IV q15 min (max 15 mg) OR diltiazem 10–20 mg IV.
  • Unstable: synchronized cardioversion; call cardiology.
  • SVT
  • Vagal maneuvers → adenosine 6 mg IV push → 12 mg if no effect.
  • Ventricular tachycardia
  • ACLS protocol, amiodarone, cardioversion/defibrillation.
  • MAT
  • Treat underlying cause (often hypoxia), rate control with verapamil or beta-blocker if tolerated.

VI. Red Flags – Call Senior Immediately

  • HR > 130 sustained.
  • Hypotension, hypoxia, altered mental status.
  • Chest pain or ST changes on EKG.
  • Evidence of bleeding (falling H/H, bloody drains, hemodynamic instability).
  • Persistent tachycardia without clear explanation after initial workup.

VII. Intern Pearls

  • Always get an EKG — don’t assume sinus tachycardia.
  • In post-op patients, tachycardia is often the first sign of hemorrhage, sepsis, or PE.
  • Don’t reflexively give beta-blockers for sinus tachycardia — treat the cause.
  • Tachycardia + fever = infection until proven otherwise.
  • Tachycardia + falling H/H = bleeding until proven otherwise.

VIII. References

  1. Sessler CN, et al. Mechanisms and management of tachycardia in critically ill patients. Crit Care Med. 2015;43(12):2641–2650.
  2. Devereaux PJ, et al. Association between postoperative troponin levels and 30-day mortality among patients undergoing noncardiac surgery. JAMA. 2012;307(21):2295–2304.
  3. Dellinger RP, et al. Surviving Sepsis Campaign: international guidelines for management of severe sepsis and septic shock. Crit Care Med. 2013;41(2):580–637.
  4. January CT, et al. 2019 AHA/ACC/HRS guideline for the management of atrial fibrillation. Circulation. 2019;140(2):e125–e151.

Key Takeaways

  • Step 1: Confirm and get an EKG.
  • Step 2: Assess stability (ABCs).
  • Sinus tachycardia = physiologic stressor → treat cause.
  • Non-sinus tachycardia = arrhythmia → follow ACLS, cardiology consult.
  • Persistent unexplained tachycardia is a red flag — bleed, sepsis, PE, ischemia until ruled out.