Care of women with puerperal psychiatric disorders in England and Wales.

cleared the other three. His total time in the water for the nine dives was 44 minutes (figure). His subsequent neurological and musculoskeletal decom-pression sickness was successfully treated with hyper-baric oxygen according to the US Navy table No 6. Surface 18 m u_ A *-Surface interval 3 hours-B _-Time Dive profile, case 1. Total time in water (A +B) was 44 minutes (US Navy no stops time at 18 metres=60 mins) Case 2-Five descents and ascents to and from 15 metres took diver 2 a total of 48 minutes and were completed without decompression stops. Subsequent musculoskeletal decompression sickness was successfully treated with reference to US Navy table 6. Case 3-Over two weeks diver 3 made 14 dives a day in rapid succession with no decompression stops. The first six dives were to 18 metres with an average time spent on the bottom of 10 minutes, followed by eight dives to 9 metres with times spent on the bottom ranging from five to 10 minutes. He continued to dive to this pattern despite developing neurological de-compression sickness. When his illness was brought to medical attention he was successfully treated, 56 hours after surfacing from his last dive, according to an extended US Navy table 6 and had follow up hyperbaric oxygen treatments. Comment Three professionally trained divers followed widely used decompression tables but sustained decompression sickness from depths considered shallow and from total times at depth within safe limits for a single descent and ascent. Repeated descending and ascending along the series of cages was the factor that caused decompression sickness. The absorption, distribution, and release of nitrogen from the body during a dive with normal air is a complex event. Doppler studies have shown that "symptomless" bubbles are formed even after shallow dives, which do not cause decompression sickness.2 In "yo-yo" diving, on subsequent descents bubbles may not be completely returned to solution, and they may become coated by clotting proteins.3 These rheological seeds may grow more quickly with subsequent dives in a sequence and cause tissue damage through em-bolisation of blood vessels. Symptomless patent foramen ovale causing arterialisation of bubbles has been postulated as a mechanism ofbubble distribution,4 and clinical studies suggest permanent neurological deficits may remain after treatment for decompression sickness.' The long term health hazards of diving are not completely known; we believe that the diving techniques used in fish farming are dangerous. A dive conducted …