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Pulmonary Barotrauma

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Other Names

  • Pulmonary Barotrauma (PBT)

Background

  • This page covers pulmonary barotrauma (PBT), a disease process occurring from divers breathing compressed air who ascend too rapidly
    • Note that this page covers PBT related to sport and recreation, and does not review iatrogenic PBT from procedures or mechanical ventilation

History

  • First described by Behnke[1] and Polak and Adams[2] in 1932

Epidemiology

  • According to DAN fatality data, 15% of barotrauma is PBT (need citation)

Pathophysiology

  • See: Dive Medicine Main
  • General
    • Characterized by damage to the lung parenchyma caused by an increase in pulmonary gas volume during a decrease in ambient pressure
    • Wide range of symptoms from very mild pneumothorax or pneumomediastinum to life threatening arterial gas embolism[3]
    • Can occur in the absence of an evident overpressure event

Etiology

  • General
    • Occur when the ambient pressure decreases, allowing dissolved gas to expand
    • Can occur from ascent to the surface from depths as shallow as 4 feet after breathing compressed air
    • Risk is likely increased with underlying obstructive pulmonary disease, however most cases do not identify a predisposing factor
  • May occur in the following scenarios[4]
    • Involuntary laryngospasm on ascent (e.g. caused by loss of consciousness, panic
    • Intentional or involuntary breath-holding while ascending (even for a short period e.g., coughing)
    • Sudden increase in the volume of gas supplied by scuba equipment
    • During a fast ascent
  • Tetzlaff and colleagues identified a reduced mid-expiratory flow at 25% of vital capacity in divers who presented with lung barotrauma[5]
    • Findings suggest pulmonary function testing could be used to perform risk assessment

Associated Conditions

  • Pneumothorax
    • Occurs when gas in the lung interstitial space enters pleural space[6]
    • 3% of patients in one case study of 31 patients[7]
    • Can be simple or tension
  • Pneumoperitoneum
    • 3% of patients in one case study of 31 patients[7]
  • Subcutaneous Emphysema
    • 10% of patients in one case study of 31 patients[7]
  • Pneumomediastinum
    • 25% of patients in one case study of 31 patients[7]
  • Pneumopericardium
    • 6% of patients in one case study of 31 patients[7]
  • Air Gas Emboli
    • Can result in stroke, cardiac arrest and death

Risk Factors

  • Diver related
    • Novice or inexperienced divers, likely related to breath holding
  • Pulmonary

Differential Diagnosis

Differential Diagnosis Dive Medicine


Clinical Features

  • History
    • Symptoms ten to occur immediately upon surfacing or within 10 minutes
    • Substernal pain exacerbated by coughing or swallowing suggests mediastinal emphysema
    • Throat pain, horseness, dysphagia, choking sensation
    • Cough, shortness of breath, hemoptysis, dypsnea, cyanosis
  • Physical Exam
    • Must perform thorough cardiopulmonary and neurological exam
    • Crunching sound on auscultation may be indicative of mediastinal air (Hamman's sign)
    • Swelling or crepitus due to subcutaneous emphysema
    • Asymmetric breath sounds if large or tension pneumothorax
    • More rarely, patients have neuro-dysfunction, cardiorespiratory distress or cardiac arrest
  • Special Tests

Evaluation

Radiograph

  • Standard Chest Radiograph
    • Helps include/ exclude things like pneuothorax, pneumomediastinum, etc
  • Findings
    • Pneumomediastinum is most commonly seen (need citation)
    • Pneumothorax
    • Subcutaneous Emphysema
    • Pulmonary edema or infiltrates

CT

  • Indications
    • No hard indications
    • Recommend angiography if any concern for AGE (Chest vs Head and Neck)
  • Potential findings
    • Arterial Gas embolism
  • Tetzlaff found 13 lung abnormalities among patients with pulmonary barotrauma[5]
    • Suggests unexplained lung barotrauma may stem from occult lung disease

Ultrasound

  • Echocardiogram
    • Can be used to detect number, size of bubbles in the right side of the heart

EKG

  • Should be obtained on all patients
  • Potential findings
    • Sinus tachycardia
    • Arrhythmia
    • Myocardial Infarction

Classification

  • Currently, no classification system exists

Management

Nonoperative

  • General
    • The patient should be transferred to the nearest Emergency Department
    • It is important that the diving team communicate with the ED staff
    • The patient should be treated with BLS and ACLS as needed
    • Obtain IV access, apply supplemental oxygen, patient may require advanced airway
  • Oxygen Therapy
    • 100% Non rebreather for mild cases is likely appropriate, however mild cases will often resolve spontaneously
    • Indicated for anyone who is hypoxic
  • Tension Pneumothorax
  • Hyperbaric Oxygen Therapy (HBOT)
    • Indicated for any limb or life threatening presentation, includes spinal cord injury, neurological impairment, myocardial infarction
    • Patient must be stable enough for hyperbaric chamber
    • Definitive treatment should be initiated within 2 hours if possible
    • Delays greater than 6 hours associated with worse outcomes (need citation)
  • Unknown benefit
    • Heliox (50% helium/ 50% oxygen mixture)
    • Surfactant
  • Restricted air travel
    • Previously recommended to wait 6 weeks until complete resolution of pneumthorax[8]
    • Current guidelines based on sparse data recommend waiting 1-3 weeks after resolution[9]

Prevention


Rehab and Return to Play

Rehabilitation

  • Needs to be updated

Return to Play/ Work

  • All divers with lung disease should be screened

Complications and Prognosis

Prognosis

  • General
    • Varies wildly based on severity
    • Mild cases have few sequalae and complete resolution
    • Air gas embolism has a 30% mortality rate (need citation)

Complications

  • Air Gas Emboli
    • 30% mortality rate (need citation)
    • Can result in stroke, cardiac arrest, death
  • Cerebral Embolization
    • Can result in loss of consciousness
    • Neuro dysfunction including hemiplegia, stupor, confusion, visual disturbance, seizures, vertigo, headache
    • Occurs within minutes of surfacing
  • Myocardial Infarction
  • Cardiac Arrest
    • Occurs in about 5% of victims
    • Due to cardiac chambers and great vessels filling with air
  • Other pulmonary complicates documented in case reports
    • Aspiration pneumonitis
    • Pneumonia
    • Pleural Effusion
    • Empyema
    • Pyopneumothorax
    • Scarring and fibrosis
    • Decreased lung function

See Also


References

  1. Behnke AR. Analysis of accidents occurring in training with the submarine “lung.” U S Nav Med Bull 1932;30:177–184.
  2. Polak B, Adams H. Traumatic air embolism in submarine escape training. U S Nav Med Bull 1932;30:165–177.
  3. Leitch DR, Green RD. Pulmonary barotrauma in divers and the treatment of cerebral arterial gas embolism. Aviat Space Environ Med. 1986;57:931–8
  4. Siermontowski P, Kozlowski W, Pedrycz A, Krefft K, Kaczerska D. Experimental modelling of pulmonary barotrauma. Undersea Hyperb Med. 2015;42:143–9.
  5. 5.0 5.1 Tetzlaff K, Reuter M, Leplow B, Heller M, Bettinghausen E. Risk factors for pulmonary barotrauma in divers. Chest 1997;112:654–659.
  6. Schaffer KE, McNulty WP Jr, Carey C, Liebow AA. Mechanisms in development of interstitial emphysema and air embolism on decompression from depth. J Appl Physiol 1958;13:15–29.
  7. 7.0 7.1 7.2 7.3 7.4 Harker CP, Neuman TS, Olson LK, Jacoby I, Santos A. The roentgenographic findings associated with air embolism in sport scuba divers. J Emerg Med 1993;11:443–449
  8. Coker R. BTS updates advice on air travel for patients with respiratory disease. Available from: https://www.guidelinesinpractice.co.uk/bts-updates-advice-on-air-travel-for-patients-with-respiratory-disease/300746.article.
  9. Hu X, Cowl CT, Baqir M, Ryu JH. Air travel and pneumothorax. Chest. 2014;145:688–94. doi: 10.1378/chest.13-2363.
Created by:
John Kiel on 7 June 2022 13:48:22
Authors:
Last edited:
25 July 2022 20:54:34
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