Acute Respiratory Failure Insights

Sep 25, 2024

ICU Curriculum Session 3: Acute Respiratory Failure

Overview of Session

  • Definitions
    • Hypoxemic Respiratory Failure (Type 1)
    • Hypercapnic Respiratory Failure (Type 2)
  • Objectives
    • Classify respiratory failure types
    • Identify patient groups for non-invasive ventilation
    • Understand reasons for intubation and mechanical ventilation
    • Learn four major ventilator variables

Case Study Overview

  • Patient: 55-year-old male with COPD
  • Symptoms: Dyspnea, low oxygen saturation
  • Intervention: Transferred to ICU, ABG results show severe respiratory acidosis

Types of Respiratory Failure

Hypoxemic (Type 1)

  • Definition: Oxygen saturation <90% or PaO2 <60 mmHg
  • Causes:
    • Low inspired oxygen
    • Hypoventilation
    • Diffusion restriction
    • VQ mismatch
    • Shunt
  • Common influences: Blood, pus, water in alveoli
  • Treatment: Nasal cannula, non-rebreather, high-flow oxygen, mechanical ventilation

Hypercapnic (Type 2)

  • Definition: PaCO2 >45 mmHg with respiratory acidosis
  • Causes:
    • Hypoventilation
    • "Won't breathe" (CNS issues)
    • "Can't breathe" (Neuromuscular issues)
    • "Can't breathe enough" (Pulmonary issues)
  • Common influences: CNS depressants, neuromuscular disorders, COPD, asthma
  • Treatment: Non-invasive positive pressure ventilation

Non-Invasive Positive Pressure Ventilation (NIV)

  • Uses:
    • COPD and asthma exacerbations
    • Cardiogenic pulmonary edema
  • Mechanism:
    • Stents open airways, reduces lung hyperinflation
    • Improves tidal volume, lowers respiratory effort
  • Evidence:
    • Reduced intubation, mortality rates

Indications for Intubation

  • Head and CNS: Altered mental status, unprotected airway
  • Airway: Copious secretions, airway trauma
  • Cardiac: Arrest, failed non-invasive in edema
  • Pulmonary: ARDS, failed NIV
  • General: Shock, procedure facilitation

Ventilator Control Variables

  • Oxygenation:
    • FiO2 (Fraction of Inspired Oxygen)
    • PEEP (Positive End Expiratory Pressure)
  • Ventilation:
    • Tidal Volume
    • Respiratory Rate

Summary

  • Defined forms of respiratory failure
  • Recognized patient groups for non-invasive ventilation
  • Discussed intubation indications
  • Identified ventilator control variables
  • Session provided practical understanding of respiratory support management

Thank you for your participation.