Decompression Sickness - Environmental Emergencies

DECOMPRESSION SICKNESS

Decompression sickness (DCS), also called “the bends,” occurs in patients who have engaged in diving, high-altitude flying, or flying in commercial aircraft within 24 hours after diving. Al-though DCS occurs in relatively few divers compared with the number of dives worldwide, its effects can be hazardous. Being aware of DCS and assessing the patient properly will ensure proper management and result in the least morbidity possible.

DCS results from nitrogen bubbles trapped in the body. They may occur in joint or muscle spaces, resulting in musculoskeletal pain, numbness, or hypesthesia. More significantly, nitrogen bub-bles can become air emboli in the bloodstream and thereby pro-duce stroke, paralysis, or death. Taking a rapid history about the events preceding the symptoms is essential. Recompression is nec-essary as soon as possible and may necessitate a low-altitude flight to the nearest hyperbaric chamber.

Assessment and Diagnostic Findings

To identify DCS, a detailed history is obtained from the patient or diving buddy. Evidence of rapid ascent, loss of air in the tank, buddy breathing, recent alcohol intake or lack of sleep, or a flight within 24 hours after diving suggests the potential for DCS. Note that some patients describe a perfect dive yet still have the signs and symptoms of DCS and must be treated as such.

Signs and symptoms include joint or extremity pain, numbness, hypesthesia, and loss of range of motion. Neurologic symptoms mimicking those of a stroke or spinal cord injury could indicate an air embolus. Cardiopulmonary arrest can also occur with se-vere cases of DCS. Because of hypoxia, these patients seldom sur-vive. Any neurologic symptoms should be rapidly assessed. All patients with DCS need rapid transfer to a hyperbaric chamber.

Management

A patent airway and adequate ventilation are established as de-scribed previously, and 100% oxygen is administered throughout treatment and transport. A chest x-ray is obtained to identify as-piration, and at least one intravenous line is started with lactated Ringer’s or normal saline solution.

The cardiopulmonary and neurologic systems are supported as needed. If an air embolus is suspected, the head of the bed should be lowered. The patient’s wet clothing is removed, and the patient is kept warm. Transfer to the closest hyperbaric chamber capable of treating DCS is initiated. The Divers Alert Network (DAN) can be contacted by telephone (1-919-684-8111) to lo-cate the nearest chamber. If air transport is necessary, low-altitude flight (below 1000 feet) is required. However, the patient who is awake and alert without central neurologic deficits may be able to travel by ground ambulance or by automobile, depending on the severity of symptoms. Throughout treatment, the patient is continually assessed, and changes are documented. If aspiration is suspected, antibiotics and other treatment may be prescribed.