Pulmonology Book

http://www.fpnotebook.com/

Acute Respiratory Failure

Advertisement

  1. See Also
    1. Dyspnea
    2. Dyspnea Causes
  2. HypoVentilatory Respiratory Failure (Bellows Failure)
    1. Defining features
      1. High PaCO2
      2. Normal A-a Gradient
    2. Causes: Compromised lung mechanics
      1. Upper airway obstruction
      2. Pulmonary muscle Fatigue
        1. Skeletal muscle Fatigues at >40% of maximum load
        2. Exacerbating factors
          1. Obesity
          2. Ascites
          3. Supine position
          4. Scoliosis
          5. Ankylosing Spondylitis
          6. Hypercarbia (fever, Sepsis, burns)
          7. Inefficient breathing (flat diaphragm, high RV)
            1. Asthma
            2. Emphysema
      3. Unstable chest wall
        1. Pneumothorax
        2. Flail chest
    3. Causes: Neuromuscular
      1. Drug overdose or depressant drugs
        1. Example: Phencyclidine (PCP)
      2. Brainstem injury
      3. Severe global CNS injury
        1. Head Trauma
        2. Intracranial Hemorrhage
        3. CNS Infection
      4. Nerve dysfunction
        1. Spinal cord injury
        2. Polyneuritis (e.g. Guillain-Barre Syndrome)
        3. Amyotrophic Lateral Sclerosis
        4. Poliomyelitis
        5. Nerve Agent Exposure (e.g. Organophosphates)
        6. Phrenic nerve injury
          1. Example: Phrenic Nerve Injury from Birth Trauma
      5. Muscular dysfunction
        1. Muscular Dystrophy
        2. Polymyositis
        3. Severe Hypophosphatemia
  3. Ventilation-perfusion mismatch (venous admixture)
    1. Defining features
      1. High PaCO2
      2. Increased A-a Gradient
      3. Often improves with Supplemental Oxygen
    2. Causes
      1. Asthma
      2. Chronic Obstructive Lung Disease (COLD)
      3. Pneumonia
      4. Pneumothorax
      5. Pulmonary Embolism
      6. Interstitial Lung Disease
  4. Hypoxemic Respiratory Failure (Right to left shunting)
    1. Defining features
      1. Low PaCO2
      2. Low PaO2
      3. A-a Gradient may be increased
      4. May not improve with Supplemental Oxygen
    2. Causes
      1. Adult Respiratory Distress Syndrome (ARDS)
        1. Increased permeability (low prEssure edema)
      2. Cardiac pulmonary edema (high prEssure edema)
        1. Left Ventricular Failure
        2. Acute Myocardial Ischemia (left ventricle)
        3. Malignant Hypertension
        4. Mitral Regurgitation or stenosis
      3. Focal Lesions
        1. Lobar Pneumonia
        2. Atelectasis
        3. Pulmonary Contusion
        4. Alveolar hemorrhage
  5. References
    1. Davies (1986) Acute Respiratory Failure, Cyberlog
    2. Presberg in Noble (2001) Primary Care, p. 705-16

Navigation Tree