Dysbarism Workup

Updated: Jun 15, 2018
  • Author: Stephen A Pulley, DO, MS, FACOEP; Chief Editor: Joe Alcock, MD, MS  more...
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Laboratory Studies

No specific tests are required for the diagnosis of dysbarism. When diving is involved, the primary consideration should be a pressure-related injury. Baseline laboratory studies usually have no bearing on initial management. They could be useful in excluding other entities on the differential diagnosis list while HBO therapy is pursued. Transfer should not be delayed. For a patient with a mental status change, routine evaluation of reversible causes is mandated. If the individual is in extremis (eg, shock), appropriate resuscitation studies should be obtained.

For changes in mental status or in medically unstable patients, consider the following:

  • Serum glucose level, CBC count

  • Electrolytes, magnesium, calcium, phosphorous, BUN, and creatinine levels

  • Oxygen saturation

  • Ethanol level, drug screen

  • Carboxyhemoglobin level

  • Type and screen, cross-match

  • Prothrombin time (PT), activated partial thromboplastin time (aPTT)


Imaging Studies

Chest radiography

Chest radiography is the primary diagnostic imaging study for overpressurization injuries.

Chest radiography can identify evidence of pneumothorax, pneumomediastinum, subcutaneous emphysema, pneumopericardium, and alveolar hemorrhage.

Sinus radiography

Opacification of the sinuses confirms the presence of pathology in that area.

It does not confirm that the pathology is related to diving.

CT scanning

CT scanning is readily available in many hospitals worldwide. Modern scanners are very fast for capture of images. It is more sensitive than plain radiography. CT scanning can readily identify barotraumatic injuries in the brain, sinuses and orbits, chest, and abdomen/pelvis and is a reasonable first-line approach when there is a concern for diving injuries. CT scanning differentiates pathology in areas of concern better than radiography.

Chest CT, especially spiral CT, is recommended for evaluation of the lungs after a pulmonary barotrauma event. It can show preexisting pathology, such as small lung cysts. [95]

Although this information is not helpful for treatment of a dysbaric injury, it can help determine future fitness for diving. CT scanning has also been advocated for detection of arterial gas embolism in postmortem examinations (see Decompression Sickness). [96]


Other Tests

Diagnostic repressurization: When a question exists as to whether the patient's problem is dysbarism or DCS, repressurization in a hyperbaric chamber can be pursued for diagnostic and therapeutic reasons. (This may require patient transfer.)

Electrocardiography may be warranted.