Barotrauma in Emergency Medicine Clinical Presentation

Patients with DCS present with a history of diving, generally within 24 hours of the onset of symptoms. Patients may also have a recent history of occupational pressurization or depressurization. For example, this occurs with aircraft mechanics who must test aircraft windows by working in pressurized aircraft. Air emboli have also occurred in mechanics who maintain training altitude chambers. Recently, military operations involving troops traveling from ground level to high-altitude environments in a relatively short time and operations involving soldiers doing strenuous activities at higher altitudes have resulted in many cases of DCS. Recent studies have indicated that aerobic exercise either prior to a dive or during decompression stops may decrease the post dive gas bubble formation.^{[2, 3]}

Sinus squeeze

Patients usually present with complaints of facial or oral pain, nausea, vertigo, or headache.

Other important information to gather includes any history of recent upper respiratory infections, allergic rhinitis, sinus polyps, and sinus surgeries and whether the pain worsened during descent or ascent.

Middle ear squeeze

Patients often have a history of sudden vertigo, nausea, tinnitus, ear pain, deafness, or headache.

They may have a history of previous diving ear injury or a history of previous or current ear infection.

Decompression sickness type I

Patients often have a history of recent diving followed by a flight home. They may complain of slowly progressing pain or numbness in their limbs or back.

Patients present with joint, muscle, or back pain that worsens over time. The pain worsens with motion but is always present. The pain may range from mild (tickles) to severe (the bends).

Patients may have a history of previous decompression illness and multiple dives in the same day and frequently have not followed the dive tables closely. New dive computers that offer more "bottom time" do so by modifying the US Navy dive tables and possibly place divers at an increased risk for DCS injuries. Divers should be questioned as to the method of computing bottom and ascent times with safety stops. This information should be recorded as part of the medical record.

Decompression sickness type II

DCS type II usually presents sooner than DCS type I.

Patients may present with shortness of breath (the chokes), chest pain, severe headache, altered mental status, and shock. They also may complain of dizziness or weakness. Patients may rapidly deteriorate without emergent intervention.

Essential history to ascertain includes time since dive ended, the dive profile (see images below), when the symptoms began, and prior medical history. The dive profile consists of prior dives that day, depth of dive, bottom time, decompression stop depth, and length of stop.

Diver should be asked about his or her prior dive category.

Inquiry should be made specifically about previous decompression injuries, pulmonary blebs, Marfan syndrome, asthma, congenital pulmonary illnesses, HIV status, chronic obstructive pulmonary disease (COPD), lung tumors, histiocytosis X, cystic fibrosis, pregnancy, and any prior pulmonary injuries or surgeries.

Arterial gas embolism

AGE usually occurs shortly after ascending very rapidly, often from fairly shallow depths. People may be described to scream suddenly and lose consciousness. Onset of AGE often occurs within a few minutes of surfacing. Patients who experience AGE often die before reaching a medical facility. Air emboli have also recently been noted to occur iatrogenically in association with central venous monitoring during surgical procedures. Case reports have shown AGE occurring secondary to occupational rapid decompression in both aircraft maintenance and altitude-chamber maintenance personnel.^[4]

Obtaining a history from these patients can be difficult because they often present with altered mental status or are in shock.

Witnesses often report that divers experience a sudden or immediate loss of consciousness or collapse, usually within minutes of surfacing.

Ask the patient or dive partner about a history of patent foramen ovale.

Abdominal compartment syndrome ^[5]

Divers can develop large amounts of intraperitoneal extraluminal gas, which can compress the intraperitoneal organs. This can lead to venous compression of these organs and secondary compartment syndrome.

The physical examination should be tailored to the patient's history.

Perform a general physical examination on all patients, with initial emphasis on ears, sinuses, and neck as well as on the pulmonary, cardiovascular, and neurologic systems. AGE often presents with signs and symptoms of acute stroke.

Inspect and palpate the extremities, and test range of motion in all joints.

Sinus squeeze

Inspect nasal mucosa for polyps, hemorrhage, or lesions.

Palpate and transilluminate sinuses to inspect for hemorrhage.

Percuss upper teeth with a tongue blade to inspect for severe sinus tenderness.

Ear squeeze

Carefully inspect the tympanic membrane (TM), looking in particular for the following signs:

• Amount of congestion around the umbo
• Percent of TM involvement
• Amount of hemorrhage noted behind eardrum
• Evidence of TM rupture

Palpate the eustachian tube for tenderness.

Test the patient's balance and hearing.

Evaluate the TM on the Teed scale:

• Teed 0 - No visible damage, normal ear
• Teed 1 - Congestion around the umbo, occurs with a pressure differential of 2 pounds per square inch (PSI)
• Teed 2 - Congestion of entire TM, occurs with a pressure differential of 2-3 PSI
• Teed 3 - Hemorrhage into the middle ear
• Teed 4 - Extensive middle ear hemorrhage with blood bubbles visible behind TM; TM may rupture
• Teed 5 - Entire middle ear filled with dark (deoxygenated) blood

Decompression sickness type I

Inspect for swelling or effusion in the affected joint.

Test for range of motion both actively and passively.

Palpate the affected area for crepitus and compartment tightness.

Evaluate neurovascular status by performing a complete neurologic examination. The examination should include testing motor and sensory functions, cerebellar function, and mental status. The findings from this examination must be recorded and used as a baseline to determine improvement in postdive chamber treatment.

Decompression sickness type II

Evaluate cardiovascular and pulmonary systems.

Note neck vein distention or petechiae on the head or neck.

Palpate the skin for crepitus.

Auscultate the lungs and heart for decreased breath sounds, muffled heart tones, or heart murmurs.

Evaluate neurologic status, including gross motor, sensory, and cerebellar examinations. Tandem walking (heel to toe, with eyes closed) is an excellent method of evaluation.

Document Glasgow Coma Scale and Mini Mental State Examination.

Arterial gas embolism

Use the same examination used for decompression sickness type II.

The causes of DCS are related to predisposing medical or genetic factors, as listed above, and to diver error. Diver error includes the following practices:

• Multiple daily dives
• Poor adherence to the dive tables
• Breath holding (most common scenario for pulmonary barotrauma)
• Rapid ascent - This can occur from relatively shallow depths. For example, pilots undergoing rapid ascent while performing underwater escape training after flight may experience DCS.
• Flying or traveling to high altitudes within 24 hours after diving
• Occupational causes - These causes include rapid depressurization by maintenance workers and mechanics after working in pressurized aircraft cabins. Reports of altitude chamber mechanics who have depressurized too quickly while working on the altitude chambers have also been documented. Pilots and crewmembers performing high-altitude air drops on military missions and special-operations soldiers involved in such missions have also reported instances of DCS.