Diagnosis and Management of Post-Operative Complications: Hypoxia

Jun 17, 2024

Diagnosis and Management of Post-Operative Complications: Hypoxia

Introduction

  • Focus on post-operative complications.
  • Emphasis on hypoxia rather than specific complications (e.g., pneumonia, PE).
  • Real-world data is limited; clinicians need to act quickly without a definitive diagnosis.
  • Goal: Stabilize the patient and methodically work towards a diagnosis.

Scenario Example

  • Patient post-op, suddenly hypoxic, requiring 6L of nasal cannula.
  • Immediate action is crucial before even knowing the full differential diagnosis.
  • Treatment and basic workup happen in parallel with initial steps.

Immediate Actions for Acutely Hypoxic Patients

  1. Increase Oxygenation

    • Increase oxygen delivery if patient is not oxygenating well enough.
    • This is essential even without a clear diagnosis.

  2. Order Immediate Workup

    • Basic investigations: Put in orders for labs and imaging (e.g., chest x-ray) as you walk up to see the patient.

  3. Level of Care Assessment

    • Determine the appropriate level of care early (general floor vs. ICU).
    • Match the level of care with patient’s current stability and treatment needs.

Respiratory Failure Basics

  • Modes of Respiration:
    • Oxygenation: Delivery of oxygen to the blood.
    • Ventilation: Removal of CO2 from the blood.
  • Clinical Concern: Immediate need to address oxygenation; ventilation considerations come later.

Spectrum of Oxygen Therapy

  1. Nasal Cannula: Low-level oxygen support through nasal prongs.
  2. Oxymask: Similar to nasal cannula but covers nose and mouth.
  3. High Flow Nasal Cannula (HFNC):
  • More oxygen support plus some positive pressure.
  • Acts as a hybrid between simple nasal cannula and more intensive support like CPAP.
  1. Positive Pressure Ventilation (PPV)
  • CPAP: Continuous positive airway pressure.
  • BiPAP: Bilevel positive airway pressure, assists with both oxygenation and CO2 clearance.
  1. Intubation and Mechanical Ventilation: Last resort if other methods fail.

Workup Strategy

  • Chest X-Ray and VBG: Order these immediately while heading to see the patient.
  • VBG: Important to assess ventilatory status (e.g., hypercarbia indicates need for BiPAP).

Level of Care Consideration

  • General Floor: Suitable for less intensive therapies (e.g., nasal cannula, oxymask).
  • Intermediate Care (IMC): For patients needing more support but not full ICU care.
  • ICU: Necessary for patients requiring intensive therapies (e.g., CPAP, BiPAP, intubation).

Developing a Differential Diagnosis

  • After initial stabilization and workup, return to considering differential diagnoses.
  • Use patient history and physical exam to narrow down causes.
  • Common causes: Atelectasis, pulmonary edema, pneumonia, bronchospasm, PE, pneumothorax, opioid overdose, etc.
  • Definitive treatment depends on the specific diagnosis (e.g., antibiotics for pneumonia, anticoagulation for PE).

Summary

  • Prioritize immediate actions: Increase oxygenation, order basic workup, determine appropriate level of care.
  • Consider differential diagnosis after initial stabilization.
  • Keep patient safe and calm throughout the process.