Correspondence (reply): In Reply

We thank Dr Cüppers and agree completely, that studying a CME article is absolutely no substitute for a specialist training qualification in diving medicine. This is obvious from our article, in which we explicitly recommend (for example, in the Overview section) attending the courses of the German Society for Diving and Hyperbaric Medicine (GTÜM) and obtain GTÜM certification by passing the two relevant courses that the association offers, “Medical Evaluation for Diving” (Tauchmedizinische Untersuchungen, GTÜM Course I) and “The Diving Physician Course” (Taucherarzt, GTÜM Course IIa). We also clearly pointed out the GTÜM’s pertinent examination standards and recommendations, seeking expert advice, making available advice over the telephone from diving medicine specialists, and relevant literature. Our article aimed to inform the wide readership of Deutsches Ärzteblatt about the physiological-physical basics of diving, about fitness to dive examinations and medical diving advice, as well as about diving emergencies and their treatment.

Attentive readers could not fail to notice that the psychological state of divers is a subject we dealt with in our article. When conducting the fitness to dive examination, doctors should pay attention to the potential diver’s psychological condition, not only in the context of a thorough medical history, but they should also conduct a critical analysis of a person’s medication (see the Box in our article). The GTÜM explicitly provides for considering the psychological state of divers with its questionnaire (www.gtuem.org).

With regard to diving incidents, Cüppers thinks that examining the psychological situation of recreational divers is more important. We do not have any robust data to contribute to this evaluation. It is therefore important during a careful diving medical examination to identify all potential risk factors, if possible. This obviously includes the psychological sector.

Dr Stockhausen rightly mentions the often lacking emergency equipment on dive boats. However, we counsel against the suggested “in-water decompression” (a repeated dive on noticing the first symptoms of decompression sickness), for a multitude of reasons: the initially mild symptoms of decompression sickness are often progressive and can deteriorate in an unforeseeable manner. Options for intervention in deep water are extremely limited, and adequate monitoring of a diver is not possible. A depth of 10 meters (=2 bar) is mostly not sufficient to eliminate the bubbles responsible for the symptoms. Although additional administration of 100% O₂ would mean that the higher concentration gradient in the lung would favor elimination of nitrogen, the induced high partial O₂ pressures are dangerous with regard to the potential of oxygen to trigger seizures. Furthermore, the gas reserves on board are not likely to be sufficient for recompression of adequate duration (the US Navy Table 6, for example, which is often used for the purposes of treatment, provides for a treatment duration of >280 min). Furthermore, the boat cannot return to base with a diver dangling from a rope, so the transfer into a decompression chamber is delayed further.

To conclude, divers should be clearly instructed to ask dive base operators for adequate emergency equipment and to find out about the emergency management on site.