Acute decompression sickness

The Laryngologist Who Saved the Brooklyn Bridge

OBJECTIVE

To understand the role of a single laryngologist, Andrew Heermance Smith, in elucidating the mechanisms of Caisson Disease and controlling it effects on bridge workers.

DATA SOURCES

Scientific and lay publications, letters and records of the Roebling family, obituaries and internet sources.

REVIEW METHODS

Historical review.

RESULTS

AH Smith combined physiological observations and experiments in the Brooklyn Bridge caissons with a review of the existing engineering and medical literature to describe the Caisson Disease and to devise strategies to ameliorate its effects.

CONCLUSION

Despite an incorrect conclusion about the pathophysiology of decompression sickness, Smith's stringent standards and timely interventions allow completion of the masonry towers of the Brooklyn Bridge.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:3044-3048, 2024.

COVID-19-related complications and decompression illness share main features.: Could the SARS-CoV2-related complications rely on blood foaming?

A study by Saraiva et al. (2011) demonstrated the presence of Angiotensin II receptors on the erythrocyte membrane. This little-known information should be deemed as crucial as the SARS-CoV-2 relationships with oxygen saturation and the Renine Angiotensin System but it currently remains unexploited. The pulmonary and cardiovascular systems are involved in any typical complications of COVID-19 but numerous other unrelated symptoms may occur. To fill the gap, we shall first emphasize some similarities between the complications of this infectious disease and Decompression Illness (DCI), which involves bubble formation. We theorized that the Angiotensin II clearance by the red blood cells could trigger the release of its oxygen content in the bloodstream. The resulting foam would worsen the widespread endotheliitis, worsen the gas exchange, trigger the coagulation process, the inflammation process and the complement pathway as typically occurs in DCI. At the end, we propose a plausible mechanism.

Analytic Reviews : Hyperbaric Oxygen Therapy

The physiological effects of hyperbaric oxygen extend beyond the elevation of oxygen concentration in body tissues, and clinical data is available to support its use in more than gas bubble diseases. Hyperbaric medicine is discussed within the context of its recognized mecha nisms of action. The experimental data and clinical ex perience for hyperbaric oxygen therapy are reviewed for the following conditions: clostridial myonecrosis, necrotizing soft-tissue infections, chronic refractory os teomyelitis, radiation necrosis, refractory cutaneous ul cerations, compromised skin grafts and flaps, crush in jury and acute peripheral ischemia, carbon monoxide poisoning, arterial gas embolism, decompression sick ness, and thermal burns. Risks associated with hyper baric oxygen therapy are discussed, and cost analysis data are noted for specific conditions.

Medical Disorders Related to Diving

Exposure to the underwater environment is associated with several unique disorders that may require recompression in a hyperbaric chamber. Increasing pressure during descent reduces the volume of the paranasal sinuses and middle ear, which, if not properly equalized, will sustain injury due to barotrauma. Barotrauma of the inner ear results in vertigo, tinnitus, and often permanent hearing loss. During ascent, expanding gas can produce lung injury accompanied by pneumothorax, mediastinal and subcutaneous emphysema, injection of air into the pulmonary veins, and arterial air embolism to the brain. Divers with pulmonary barotrauma often present with unconsciousness, seizures, or other evidence of cerebral dysfunction. Rapid treatment with recompression often reverses the cerebral deficits. Air embolism lesions are usually diffuse, in contradistinction to a stroke which usually follows the distribution of a single cerebral artery. Decompression sickness is a disorder caused by evolution of supersaturated dissolved gas in tissues and blood following exposure to increased pressure. Protocols for avoiding excess supersaturation during ascent from depth have been available for more than 100 years, and diving is considered safe when established decompression schedules are followed. Decompression sickness causes pain in the joints of the upper and lower extremities, and can injure the spinal cord. Paralysis, paresthesias, sensory loss, and bowel and bladder paralysis accompany spinal cord injury. Treatment involves recompression and oxygen. Platelet inhibitors and other anti-inflammatory drugs are also useful. A diving disorder must be considered in any patient with a neurologic syndrome, vertigo, hearing loss, or joint pain following diving.

[Neurological decompression illness in a Japanese breath-held diver: a case report]

We report a Japanese breath-hold diver (Ama) who presented neurological disorders after diving. He repeated diving into 25-30 meters depth in the sea for 6 hours. After diving, he felt dizziness and unsteady gait. Neurological examination showed left quadrant hemianopia, bilateral limb ataxia and ataxic gait. Head CT revealed gas bubbles in the left parietal lobe. In CT scan on 3 days after onset, gas bubbles disappeared and low density areas were observed in the bilateral parietal lobes. Brain imaging (DWI, T(2)WI and FLAIR) demonstrated high intensity in the parieto-occipital lobes. Neither pulmonary barotrauma nor intracardiac shunt was detected. He was diagnosed as having neurological decompression illness and therefore underwent hyperbaric oxygen therapy. The pathogenesis of this case was considered to be microbubbles induced by decompression. The present case suggests that repetitive rapid surfacing from the deep sea causes neurological decompression illness even in the breath-hold diver.

[Central nervous system involvement in patients with decompression illness]

Dysbarism or decompression illness (DCI), a general term applied to all pathological changes secondary to altered environmental pressure, has two forms decompression sickness (DCS) and arterial gas embolism (AGE) after pulmonary barotrauma. Cerebral and spinal disorders have been symptomatically categorized as AGE and DCS, respectively. Magnetic resonance images (MRIs) of divers with DCI showed multiple cerebral infarction in the terminal and border zones of the brain arteries. In addition, there were no differences between MRI findings for compressed air and breath-hold divers. Although the pathogenesis of the brain is not well understood, we propose that arterialized bubbles passing through the lungs and heart involved the brain. From the mechanisms of bubble formation, however, this disorder has been classified as DCS. We propose that there is a difference between clinical and mechanical diagnoses in the criteria of brain DCI. In contrast to brain injury, the spinal cord is involved only in compressed air divers, and is caused by disturbed venous circulation due to bubbles in the epidural space. The best approach to prevent diving accidents is to make known the problems for professional and amateur divers.

Cerebral vasculopathy in divers

Brains from 12 amateur and 13 professional divers, all but one of whom died accidentally, were examined neuropathologically. Grossly distended, empty vessels (presumably caused by gas bubbles) were found in the brains of 15 out of 22 divers who died from diving accidents. Perivascular lacuna formation was found in cerebral and/or cerebellar white matter in three amateurs and in five professionals. In addition to lacuna formation, hyalinization of vessel walls was present in the brains of three amateurs and five professionals. Necrotic foci in grey matter occurred in seven cases and perivascular vacuolation of white matter occurred in seven cases. The vascular changes probably arose from intravascular gas bubble formation. In one professional diver, there was also unilateral necrosis of the head of the caudate nucleus.

Cerebral perfusion deficits in dysbaric illness

Decompression sickness (DCS) is usually categorised as type I (mild; peripheral pain, non-neurological) or type II (serious; neurological). Type II is regarded as predominantly a spinal cord disease with infrequent cerebral involvement. Cerebral perfusion was studied by injection of 99Tcm-hexamethylpropyleneamine oxime and single photon emission tomography in 28 divers with confirmed incidents of DCS and cerebral arterial gas embolism (CAGE). Cerebral perfusion deficits were present in all 23 cases of type II DCS and in all 4 cases of CAGE. No deficits were present in the single case of type I DCS. Type II DCS should be recognised as a diffuse, multifocal, central nervous system disease.

Iatrogenic pulmonary overpressure accident

An unconscious victim of an overdose was intubated with an endotracheal tube to prevent aspiration. The respiratory therapist deflated the cuff of the endotracheal tube to allow for a retrograde oral air leak and then tightly attached the oxygen tube directly to the endotracheal tube. Seconds later there was a loud pop as the oxygen tube blew off the end of the endotracheal tube. The patient sustained both a hemodynamic and a neurologic decompensation as the result of marked pulmonary overinflation, with bilateral pneumothoraces and probable cerebral and coronary artery air emboli. We present the case in the hope that it will help avoid any such future occurrences.

Fatal dissecting aneurysm of the aorta in a diver

A 20-yr-old trained sports diver developed severe chest pain shortly after decompressing from a 40 m repetitive freshwater sinkhole dive, and died 6 h later. An autopsy examination showed a dissecting aneurysm of the aorta with rupture into the left pleural cavity. The relationship between the fatal event and the diving is discussed.

Urinary problems in decompression sickness

The records of 25 patients with type II decompression sickness and urinary problems have been reviewed. Seventeen patients were professionals and 8 were above the age of 40. The disease appeared within the 1st hour of emergence from the water in 70% of the cases and within the first 4 hours in the remaining 30%. Nine patients were diagnosed as paraplegic and two as tetraplegic. All patients had urinary disturbances and 14 were on Foley-catheter drainage during the decompression while 11 were on intermittent catheterisation. Fifteen patients had improved urinary function after recompression, 8 had some difficulty, 2 underwent a sphincterotomy and one a transurethral prostatectomy. The low percentage of complete recovery was due to the delayed arrival at the decompression chamber.

Spinal cord injury resulting from scuba diving

With the recent increase in the number of scuba divers, there has come a concomitant increase in the cases of decompression sickness. About 24% of these cases have some neurological consequence involving the spinal cord and the potential to render a victim permanently paraplegic. The initial symptoms may be obvious or insidious and progressive. Victims have presented themselves to a physician days later complaining only of low back pain. If not suspected, the diagnosis may be overlooked and a victim may become permanently paraplegic. Twenty-five cases of spinal injuries resulting from decompression illness over a 5-year period treated at the University of South ern California Catalina Marine Science Center are reviewed. Emergency treatment was required and consisted of recompression and O2 therapy under pressure in a hyperbaric chamber to immediately pre vent the progression of the illness and lead to a reversal of pathology in the majority of cases. It is recommended that hyperbaric treatment be initiated early to best prevent progression of the disease, how ever, late treatment is helpful, even after 10 days. Adjunct therapy advised consists of 100% O 2 by mask, Ringer's solution, dextran 40, dexamethasone, and rapid sea-level transport of a victim to a de compression chamber. If air transport is used, the altitude should be maintained at 800 feet or less, or aircraft capable of sea-level pressurization should be used. It is also advised that one not drive or fly for a period of time after scuba diving. It is hoped that increased awareness of this problem on the part of physicians will accomplish prompt and thus more ef fective treatment.

Pneumatosis oculi and spontaneous hyphema in association with pneumatosis intestinalis

A premature infant with acute necrotizing enterocolitis, Escherichia coli sepsis, and disseminated intravascular coagulation developed spontaneous bilateral hyphemas at 3 days of age. The necrotizing enterocolitis was associated with gas bubbles in the intestinal walls. The anterior chambers of both eyes also contained bubbles of gas, formed possibly by a mechanism similar to those in the intestine.

Nitrogen-oxygen saturation therapy in serious cases of compressed-air decompression sickness

Decompression sickness and arterial air embolism which follow exposure to raised environmental pressures of compressed air are usually adequately treated by accepted recompression procedures of relatively short durations. With serious cases, however, conventional treatment may not allow sufficient time at depth for the complete resolution of manifestations because of the need to avoid pulmonary oxygen toxicity which is associated with a prolonged period of breathing compressed air. Treatment by nitrogen-oxygen saturation at a pressure equivalent of 30 m (100 ft) sea water is proposed. Based upon the success of three refractory cases treated by this procedure, recommendation are made for the conversion of standard compressed-air chambers into an emergency saturation mode for therapy.

Paraplegia due to decompression sickness

Eight patients with spinal cord lesions due to decompression sickness are described. The cord lesions were in the cervical cord in four cases and in the upper dorsal cord in the other four, seven patients had incomplete lesions, one had a complete lesion, all patients were spastic. The diving details and description of the onset of paralysis are given and possible pathological processes are discussed. Prophylaxis is by adequate use of decompression stops. The most satisfactory treatment is immediate recompression.

Venous air embolism during neurosurgery. A comparison of various methods of detection in man

A comparison of the various methods available for the detection of air embolus has been carried out in patients undergoing posterior fossa exploration in the sitting position. A group of 17 patients (Group A) was comprehensively monitored by a central venous catheter, an infra-red carbon dioxide analyser and a Doppler ultrasonic flow transducer in addition to more traditional clinical methods. Group B (19 patients) was monitored by commonly used clinical methods consisting of continuous palpation of the radial pulse, intermittent blood pressure measurement, the use of an oesophageal stethoscope and the electrocardiograph. In Group A the detection of air embolus varied from 6% using an oesophageal stethoscope to 58% by the Doppler method. In Group B air embolus was diagnosed in 10% of patients. One patient in each group died from air embolus; one patient had a paradoxical embolus to the coronary arteries. It is concluded that comprehensive monitoring for air embolus, including the use of Doppler ultrasound, is an essential part of the management of these patients, for both diagnosis and treatment.

Air embolism and decompression sickness in scuba divers

The recognition and prompt treatment of air embolism and decompression sickness by the emergency physician can do much to reverse the unfavorable outcome of these two medical emergencies. Recognition depends on the physician maintaining a high index of suspicion. While the primary treatment for these disorders is recompression, other forms of therapy are outlined which must be instituted promptly.