Fortnightly Review: Medical aspects of scuba diving

Abstract

In this review I will discuss aspects of diving medicine that cause clinical problems but are considered only in specialist postgraduate training. Experience suggests that most problems arise in determining fitness to dive and in recognising and treating medical conditions caused by exposure to raised environmental pressure. People's obsession with the underwater world began long before recorded history. Diving is considered in Greek mythology. Plutarch tells of an extraordinary fishing competition, using divers, between Anthony and Cleopatra, and Pliny refers to the use of military swimmers. As underwater endurance and depth are limited by the ability to hold breath, people have continually striven to extend their underwater capabilities by mechanical means. From the fourteenth century onwards various designs for equipment have been found, including some attributed to Leonardo da Vinci. The use of diving bells is well recorded, one of the earliest being by Alexander the Great during the siege of Tyre in about 332 BC. Edmund Halley designed and used a bell to dive in the Thames in 1690, achieving a depth of 10 fathoms (60 feet of sea water; 18 m of sea water) for about one and a half hours. Such systems were clearly the forerunners of modern bell diving systems. In 1819 Augustus Siebe introduced the “open diving dress,” the antecedent of the well known copper helmeted “standard diver,” supplied with air under pressure from pumps operated at the surface. Developing technology improved pump performance and hence the depths that could be achieved. The apparent poor performance of military divers in the first decade of this century prompted the Admiralty to commission an investigation. Far from criticising the men, the report identified nitrogen narcosis and hypercarbia as the physiological limitations on ability.1 The investigations also described the first scientific approach to decompression modelling and provided …