Salt water aspiration syndrome
| Salt water aspiration syndrome | |
|---|---|
| Other names | Saltwater aspiration syndrome |
| Specialty | Undersea medicine |
| Symptoms | Cough, shortness of breath, chest discomfort, fever, malaise, shivering, headache, nausea |
| Usual onset | Immediately after an underwater dive |
| Duration | ~ 24 hours |
| Causes | Lung inflammation caused by inhalation of salt water |
| Diagnostic method | Clinical |
| Treatment | Normobaric oxygen therapy |
Salt water aspiration syndrome or saltwater aspiration syndrome is a medical condition caused by the inhalation or aspiration of small amounts of salt water, leading to lung irritation and inflammation. Unlike drowning or near-drowning, it does not involve ingestion of large volumes of water. It often results from faulty diving equipment or improper breathing techniques, allowing fine water droplets to reach the lower respiratory tract.
The condition often begins with coughing and shortness of breath, followed by chest pain, fever, and chills. It can resemble a viral infection but improves within hours, especially with normobaric oxygen therapy. While most cases resolve on their own, severe instances may require intensive care. Diagnosis is based on clinical history and symptom progression. Salt water aspiration syndrome was first described in 1970.
Cause and mechanism
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Salt water aspiration syndrome occurs when small amounts of hypertonic salt water is inhaled or aspirated, causing lung irritation and inflammation. Unlike drowning or near-drowning, it does not involve inhaling large amounts of liquid. Factors such as faulty diving regulators, improper breathing techniques, or buddy breathing lead to the inhalation of fine salt water droplets. Due to the droplets' small size, they reach the lower respiratory tract without significantly triggering the upper airway's cough reflex.[1] Marine microorganisms and particulates can contribute to inflammation in lungs, which may explain systemic symptoms associated with the syndrome.[2]
Signs and symptoms
[edit]Salt water aspiration syndrome often begins with an aspiration event. Immediately after an underwater dive, the first symptom is usually a cough, sometimes producing sputum that may be excessive or blood-tinged. Within the next two hours, divers may develop bluish skin, shortness of breath, increased respiratory rate, increased heart rate, chest discomfort and pain.[1] In rare but severe cases, low oxygen levels in blood and inflammation of lungs can occur.[3] Lungs auscultation may reveal abnormal breath sounds such as rhonchi,[1] and chest imaging can show prominent lung markings or opacities.[3] Blood work usually does not show specific abnormalities, but slightly elevated white blood cell count and lactate dehydrogenase levels may be seen.[1]
Salt water aspiration syndrome generally mimics symptoms of an acute viral infection. Fever, malaise and chills are most commonly reported, and usually the first constitutional symptoms to appear. Most individuals experience tremors and shivering[4][2] – the latter is often worse with reduced oxygen supply.[5] Headaches are reported in about two-thirds of cases, while about one-third experience body aches. Gastrointestinal involvement can result in loss of appetite, nausea and vomiting. Less commonly, affected individuals experience fainting, temporary loss of consciousness and mild confusion.[1]
Diagnosis
[edit]The diagnosis of salt water aspiration syndrome is based on medical history and physical examination. Its initial symptoms of cough and difficulty breathing are similar to near-drowning, however near-drowning does not cause viral infection-like symptoms. Furthermore it can be difficult to distinguish the condition from an acute viral infection at first; unlike viral illnesses however, salt water aspiration syndrome tends to improve within a few hours.[2] The condition shares some symptoms with decompression sickness but can be differentiated based on the dive profile and the presence of other decompression-related symptoms. Significant improvement after supplementation with normobaric oxygen therapy further supports the diagnosis of salt water aspiration syndrome.[A] Other conditions like pulmonary barotrauma, immersion pulmonary edema and low body temperatures can produce similar symptoms or occur alongside this syndrome; these can be distinguished through the clinical course and imaging results.[1]
Treatment
[edit]Treatment involves supportive care with normobaric oxygen therapy, observation and rest. Most cases resolve within the first 24 hours,[1] often spontaneously without treatment.[2] Intensive care unit (ICU) care may be necessary for severe cases or cases complicated with other diving and respiratory disorders.[3]
Research
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The condition was first described in 1970 by Carl Edmonds, who documented 30 cases at the Royal Australian Navy School of Underwater Medicine.[2] A 1989 study estimated that 37 percent of deaths that occurred during recreational scuba diving in Australia and New Zealand in the 1980s involved salt water aspiration syndrome. The study hypothesized—based on reports of the victims symptoms and an analysis of their equipments—that the syndrome acted as an intermediate factor, exacerbating panic and exhaustion, which ultimately led to loss of consciousness.[7] In 2019, a case study described severe salt water aspiration syndrome in an individual requiring ICU admission which was caused by salt water splashed by a beluga whale at Georgia Aquarium during a show.[3]
Notes
[edit]- ^ Decompression sickness will improve significantly with hyperbaric oxygen therapy, not normobaric.[6]
References
[edit]- ^ a b c d e f g Edmonds, Carl; Bennett, Michael; Lippmann, John; Mitchell, Simon (2015). Diving and Subaquatic Medicine (5th ed.). Boca Raton, Florida: CRC Press. pp. 303–307. ISBN 978-1-4822-6013-7.
- ^ a b c d e Mitchell, Simon (2002). "Salt water aspiration syndrome". South Pacific Underwater Medicine Society Journal. 32 (4). Melbourne, Australia: South Pacific Underwater Medicine Society: 205–206. ISSN 0813-1988.
- ^ a b c d Rabih, Fadi; Velasquez, Alvaro (October 2019). "Splash by a beluga whale: an unusual case of salt water aspiration syndrome". Chest. 156 (4). Glenview, Illinois: American College of Chest Physicians: A1573. doi:10.1016/j.chest.2019.08.1387. ISSN 1931-3543.
- ^ Edmonds, Carl (1970-09-01). "A salt water aspiration syndrome". Military Medicine. 135 (9). Gaithersburg, MD: Association of Military Surgeons of the United States: 779–785. doi:10.1093/milmed/135.9.779. ISSN 0026-4075. PMID 4991232.
- ^ Bullard, Robert (December 1961). "Effects of hypoxia on shivering in man". Aerospace Medicine. 32. Alexandria, Virginia: Aerospace Medical Association: 1143–1147. ISSN 0001-9402. PMID 13874609.
- ^ Richard, Moon; Mitchell, Simon (2019). "Hyperbaric treatment for decompression sickness: current recommendations". In Moon, Richard (ed.). Hyperbaric Oxygen Therapy Indications (14th ed.). North Palm Beach, Florida: Best Publishing Company. ISBN 978-1-947239-17-3.
- ^ Edmonds, Carl; Walker, Douglas (1989). "Scuba diving fatalities in Australia and New Zealand: 1. The human factor". South Pacific Underwater Medicine Society Journal. 19 (3). Melbourne, Australia: South Pacific Underwater Medicine Society: 94–104. ISSN 0813-1988.
