in this regard was that, in the 1969 dive, the deep and shallow excursions had 

 been separated by a two-hour return to the habitat.) 



A second subject in Mission 2-50 experienced bends pain in excursion diving. 

 In this instance, the subject made a two-hour-long excursion to 55 FSW, 

 followed by a further descent to 65 FSW lasting a half hour. He then 

 ascended to 25 FSW and noted pain in his right ankle, which resolved upon 

 his return to the habitat. 



In the possible third instance of bends, in Mission 12-50, the subject 

 reported vague joint pains, which persisted for two days, following a dive to 

 75 FSW. However, doubt that this was a genuine case of bends arises from the 

 fact that the subject simultaneously had symptoms of a viral infection; this 

 infection may well have been the source of his joint pains. 



Bends symptoms during decompression procedures : 



The decompression schedule used in the first two missions of TEKTITE II 

 (Appendix A) was the same one used in the TEKTITE I decompression. Two of the 

 Mission 2-50 aquanauts who had also served in TEKTITE I, as well as a third 

 scientist, reported the same bends symptomatology that they had experienced 

 in the earlier project: mild, fleeting joint pains immediately following 

 ascent to the various pressure stops up to 20 FSW, which disappeared during 

 the stop itself and were gone when the subjects reached surface pressure. 



This experience suggested that the decompression table was inadequate as 

 structured for the greater depths. Therefore, it was proposed to the Medical 

 Advisory Board, and approved by it, that two half-hour periods of oxygen 

 breathing be added at 30 and 25 FSW, plus the two five-minute "ascent" periods 

 to the next stop. 



From Mission 3-50 onward, the teams were decompressed according to the revised 

 table (see Appendix B) . Five subjects noted mild, fleeting pains (all recorded 

 retrospectively on a questionnaire sent to the aquanauts in early 1971). In 

 addition, the same subject who had had a viral infection and had experienced 

 joint pains on an excursion dive noted similar pains for two hours at the 

 10-FSW stop. There was only one case of dysbarism during decompression 

 recorded at the time. 



This subject experienced a mild, persistent pain in her right elbow at the 

 20-FSW stop and again at the 15-FSW stop. In each instance the pain was 

 relieved by oxygen breathing, and did not recur. Within a half hour of 

 reaching surface pressure, however, this subject experienced a mild pain in 

 her right knee. The pain in the knee, of Grade 1 severity, was continuous and 

 was accentuated by standing or weight-bearing. Therapy should logically have 

 taken the form of recompression in the chamber; but the environmental control 

 system had failed during decompression, and the temperature in the chamber had 

 risen to a mark over 100°F. An attempt was therefore made to relieve the 

 symptoms with oxygen inhalation at surface pressure. This procedure relieved 

 the symptoms to a degree, and the pain became intermittent rather than persistent. 

 Inasmuch as the pain persisted for two hours, another period of oxygen inhalation 

 was introduced for an additional 45 minutes, with the result of complete relief 

 of symptoms, of which there was no recurrence. As has been mentioned, X-ray 

 examination made some three months later revealed no residual effect of this 

 attach of dysbarism. 



IX-9 



