Incident Insights

Incident Insight reprinted from Alert Diver magazine
By Marty McCafferty

In Denial

Small, easy-to-ignore symptoms are often the first signs of decompression sickness.


The diver was a 52-year-old female who had been certified for 19 years and logged more than 400 dives in locations throughout the world. She had no known medical history, took no medications and had no previous diving injuries. She and her dive group were on a liveaboard traveling near an archipelago in the northern Indian Ocean.

The Incident

This diver participated in a series of 10 dives over four days. All her dives were on air and conducted within her computer's no-decompression limits. The deepest dive of her series was to 96 feet, with her other dives all being to the same or shallower depths. On day three of the dive trip, she chose not to participate in two morning dives due to a headache, nausea and pain in both hips. She noted that the location of her hip pain was in the muscles, not the joints. Later that same day she felt well enough to rejoin the group for three afternoon dives. Of note, she did not report the symptoms to the dive group leader.

Approximately one hour after the last dive, her headache, nausea and hip pain returned along with a new symptom: thigh pain. There was no skin discoloration on either her hips or thighs. While returning to her cabin below deck, she appeared to have difficulty walking down the stairs; this caught the attention of the dive leader, who evaluated her and subsequently called DAN®.

The symptoms reported to the on-call medic indicated possible decompression sickness (DCS) with neurological involvement, and the medic recommended immediate oxygen therapy. He also recommended a full evaluation by a dive physician as soon as possible and provided the location and contact information for the nearest hyperbaric facility. The group leader understood the recommendations and relayed them to the boat crew.

The Complications

The liveaboard was not affiliated with a U.S.-based operator, and English fluency varied widely among the crew members. In addition to communication barriers, the crew members also appeared unfamiliar with the emergency oxygen equipment, which apparently contributed to a delay in oxygen administration. Ultimately these issues were resolved, and the patient received high-flow oxygen via a non-rebreather mask. The vessel's remote location further complicated the scenario and prolonged the transit time required to reach an appropriate medical facility.

The diver received four hours of oxygen and noted a marked reduction in her symptom severity, and treatment was discontinued. During that time a local dive physician was contacted by phone, and, after a review of the symptoms, the physician recommended an evaluation to be followed by possible hyperbaric treatment.

The next morning (more than eight hours after the original onset of symptoms), the dive group leader contacted DAN with an update. The DAN medic emphasized the need for further evaluation due to the possibility of undetected neurological symptoms. Since the liveaboard was still several hours from the chamber, the boat crew arranged for a local speedboat to transport the patient quickly and safely to the hospital.

The Diagnosis

At the medical facility, the diver was evaluated and treated in a hyperbaric chamber following the U.S. Navy Treatment Table 5 (TT5). Her leg and hip soreness improved with the first treatment. She was brought back the next day for a subsequent TT5, and she noted additional improvement. After this second hyperbaric treatment, she was discharged back to the boat and instructed to refrain from diving for the rest of her trip.

Over the next three days, the residual soreness in her legs and hips resolved, and she returned home to the United States five days after her last treatment without any recurrence of symptoms. Within four months after the incident, she was deemed fit to dive and returned to diving without incident or symptoms.

The Discussion

Remote travel can complicate medical management. Limited facilities, long travel times and language barriers all affect a situation and how it is handled. Fortunately for this diver, the outcome was positive.

One of the many challenges facing practitioners of dive medicine is the often subtle presentation of DCS. Initial symptoms, such as hip pain or skin rashes, may be mild, and they are easily misattributed to non-diving-related causes. To complicate matters, people on dive boats want to dive and will deny or underplay symptoms in an effort to return to the water. It is every diver's responsibility to discuss symptoms with available dive staff or with DAN, even when he symptoms seem insignificant.

Try to refrain from self-diagnosis, and fight the temptation to downplay post-dive symptoms. As an example, the fact that this diver had difficulty walking down the stairs may not have been due to DCS, but it certainly wasn't normal, and it warranted evaluation.

If you experience any post-dive symptoms that could indicate DCS (see box), and especially if you experience a combination of symptoms, stop diving immediately. Seek assistance from a dive professional or the DAN medical staff at +1-919-684-9111. Continued diving may worsen the condition and may make treatment more difficult.

In addition, the location of a dive physician or the nearest medical facility should be in your emergency action plan. A final recommendation is to question your dive operator or resort regarding how they manage emergencies. Ultimately, each of us is responsible for our own safety, and the more prepared we are, the better off we'll be when trouble occurs.

Symptoms of Decompression Illness

Decompression illness (DCI) encompasses decompression sickness (DCS) and arterial gas embolism (AGE). Injured divers may have just one of the following signs and symptoms of DCI, or they may have several at the same time. DCI is unpredictable.

COMMON SIGNS AND SYMPTOMS OF DCI:
• Numbness
• Headache
• Dizziness
• Nausea
• Pain
• Weakness
• Unusual fatigue
• Difficulty walking

OTHER SIGNS AND SYMPTOMS OF DCI:
• Difficulty breathing
• Visual disturbance
• Decreased skin sensation
• Restlessness
• Itching/rash
• Paralysis
• Muscle twitching
• Unconsciousness
• Speech disturbance
• Personality change
• Altered level of consciousness
• Bladder/bowel problems
• Convulsions
• Hearing loss/ringing ears


© Alert Diver — Spring 2010