Clinical Indications for Hyperbaric Oxygen Therapy

Hyperbaric or diving-medicine consultation should be obtained for suspected decompression sickness, particularly when symptoms develop following a plausible decompression exposure.

Urgent consultation is especially important for:

• Motor weakness
• Difficulty walking
• Sensory deficits
• Bladder or bowel dysfunction
• Severe or progressive neurologic symptoms
• Vertigo or other significant vestibular symptoms
• Altered mental status
• Cardiopulmonary symptoms
• Dyspnea
• Hypotension
• Shock
• Severe or persistent musculoskeletal pain
• Cutis marmorata
• Progressive symptoms
• Symptoms that recur after initially improving with oxygen

Even apparently mild symptoms should be discussed with a clinician experienced in diving medicine when DCS is reasonably suspected.

Timing of Recompression

Recompression should generally be initiated as soon as practical when clinically indicated.

Treatment delays may allow initially reversible tissue dysfunction to progress toward permanent injury, particularly in serious neurologic decompression sickness.

However, there is no universal time cutoff after which consultation or HBOT becomes inappropriate.

Patients may present after substantial delays because:

• Symptoms were initially mild
• DCS was not recognized
• The dive occurred in a remote location
• Transportation was difficult
• Symptoms initially improved
• Access to a suitable recompression chamber was limited

Delayed presentation should therefore trigger individualized assessment rather than automatic exclusion from treatment.

Hyperbaric Treatment Approach

Hyperbaric treatment for decompression sickness typically uses established recompression treatment tables rather than the shorter treatment profiles commonly used for chronic hyperbaric indications.

A commonly used initial treatment for significant DCS is the U.S. Navy Treatment Table 6 or an equivalent recompression protocol.

The appropriate treatment table is selected by the hyperbaric physician according to:

• Type and severity of manifestations
• Neurologic findings
• Cardiopulmonary involvement
• Response during recompression
• Time to treatment
• Previous treatment
• Operational circumstances
• Available chamber capabilities

Treatment may be extended when symptoms improve incompletely during the initial recompression.

Patients with significant residual manifestations may require additional hyperbaric treatments.

The treatment strategy should be individualized by a physician experienced in diving and hyperbaric medicine.

Neurologic Decompression Sickness

Neurologic involvement represents one of the most consequential forms of DCS.

Spinal cord DCS may initially produce subtle symptoms such as:

• Tingling
• Leg heaviness
• Mild gait disturbance
• Abnormal sensation

These findings may progress to substantial weakness, sensory loss, bladder dysfunction, or paralysis.

A careful neurologic examination should therefore be performed and documented whenever DCS is suspected, even when the patient’s primary complaint appears to be musculoskeletal pain.

Serial examinations are valuable because neurologic findings may evolve during transport, oxygen treatment, or recompression.

Persistent neurologic deficits following initial HBOT may warrant additional recompression treatment, rehabilitation, and specialty neurologic follow-up.

Transportation to a Hyperbaric Facility

Transportation decisions should be coordinated with the receiving hyperbaric or diving-medicine team whenever possible.

Additional ascent to altitude can worsen decompression stress.

For symptomatic patients, unnecessary commercial air travel or travel over significant elevations should therefore be avoided unless the transportation strategy has been specifically evaluated by the medical team.

When air evacuation is medically necessary, aircraft pressure and flight altitude become clinically relevant considerations. A pressurized aircraft capable of maintaining near-sea-level cabin pressure is preferred when available.

If transport must occur by unpressurized aircraft, flight planning should minimize altitude as safely as practical.

The safest and fastest route to definitive care depends on geography, clinical severity, transportation options, and the availability of an appropriate recompression facility.

HBOT as Part of Multidisciplinary Care

Although recompression is the definitive therapy for DCS, patients may require additional management depending on the severity and organs involved.

Care may involve:

• Emergency medicine
• Hyperbaric medicine
• Diving medicine
• Critical care
• Neurology
• Pulmonology
• Otolaryngology
• Physical medicine and rehabilitation
• Physical and occupational therapy

Patients with severe neurologic DCS may require prolonged rehabilitation even after successful recompression.

Associated diving conditions must also be considered, including:

• Arterial gas embolism
• Pulmonary barotrauma
• Pneumothorax
• Immersion pulmonary edema
• Hypothermia
• Near drowning
• Trauma
• Marine envenomation
• Cardiac events

The presence of another medical condition does not necessarily exclude DCS, as more than one dive-related injury may occur simultaneously.

Clinical Evidence and Guidelines

Decompression sickness is recognized by the Undersea & Hyperbaric Medical Society as an accepted indication for Hyperbaric Oxygen Therapy.

Unlike many elective medical therapies, conventional randomized trials comparing recompression with no recompression are neither practical nor ethically appropriate in serious DCS because recompression has long been considered definitive treatment.

The evidence base therefore includes extensive clinical experience, observational evidence, physiologic research, military and commercial diving experience, treatment-series data, and international expert consensus.

European hyperbaric medicine consensus recommendations classify decompression illness among the conditions for which HBOT is strongly recommended.

These recommendations support:

• High-concentration oxygen as initial first aid
• Appropriate fluid resuscitation
• Recompression using established treatment tables
• Additional treatment when clinically significant residual manifestations persist

Current diving-medicine guidance similarly identifies recompression with hyperbaric oxygen as definitive treatment for DCS.

Medicare Coverage

Decompression illness is specifically listed as a covered condition under the Centers for Medicare & Medicaid Services National Coverage Determination for Hyperbaric Oxygen Therapy (NCD 20.29).

Coverage recognition does not guarantee payment for every individual treatment.

Applicable documentation, coding, medical necessity, facility, and payer requirements should be reviewed.

When to Refer

Consider immediate diving-medicine or hyperbaric consultation when a patient develops symptoms compatible with decompression sickness following diving, altitude exposure, or another significant decompression event.

Particular concern is warranted for:

• Neurologic deficits
• Weakness or paralysis
• Difficulty walking
• Altered sensation
• Bladder or bowel dysfunction
• Vertigo or significant vestibular symptoms
• Altered mental status
• Dyspnea or other cardiopulmonary manifestations
• Hypotension
• Severe or persistent joint or limb pain
• Cutis marmorata
• Progressive symptoms
• Recurrence of symptoms after oxygen administration

Do not rule out decompression sickness solely because imaging is normal, the dive computer recorded no decompression violation, or symptoms improve after surface oxygen.

When DCS is suspected, early communication with an appropriate hyperbaric facility can help determine the need for recompression and coordinate safe transport.