Optimal oxygen pressure and time for reduced bubble formation in theN2-saturated decompressed prawn

• Published in: Journal of applied physiology (1985) 2005-04, Vol.98 (4), p.1309
• Main Authors: Ertracht, O, Arieli, R, Arieli, Y, Ron, R, Erlichman, Z, Adir, Y
• Format: Article
• Language: English
• Subjects: Diving; Oxygen
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.01051.2004

Israel Naval Medical Institute, IDF Medical Corps, Haifa, Israel Submitted 23 September 2004 ; accepted in final form 22 November 2004 Bubbles that grow during decompression are believed to originate from preexisting gas micronuclei. We showed that pretreatment of prawns with 203 kPa oxygen before nitrogen loading reduced the number of bubbles that evolved on decompression, presumably owing to the alteration or elimination of gas micronuclei (Arieli Y, Arieli R, and Marx A. J Appl Physiol 92: 2596–2599, 2002). The present study examines the optimal pretreatment for this assumed crushing of gas micronuclei. Transparent prawns were subjected to various exposure times (0, 5, 10, 15, and 20 min) at an oxygen pressure of 203 kPa and to 5 min at different oxygen pressures (P O 2 values of 101, 151, 203, 405, 608, and 810 kPa), before nitrogen loading at 203 kPa followed by explosive decompression. After the decompression, bubble density and total gas volume were measured with a light microscope equipped with a video camera. Five minutes at a P O 2 of 405 kPa yielded maximal reduction of bubble density and total gas volume by 52 and 71%, respectively. It has been reported that 2–3 h of hyperbaric oxygen at bottom pressure was required to protect saturation divers decompressed on oxygen against decompression sickness. If there is a shorter pretreatment that is applicable to humans, this will be of great advantage in diving and escape from submarines. decompression; bubbles; diving Address for reprint requests and other correspondence: R. Arieli, Israel Naval Medical Institute, POB 8040, Haifa 31080, Israel (E-mail: rarieli{at}netvision.net.il )