Dujic
Exogenous Nitric Oxide may reduce bubble formation in both wet and dry divers.
| Clinical Bottom Line: 1. Dry diving produces fewer bubbles than wet diving.2. Nitroglycerine probably reduces bubble formation in both wet and dry dives. |
Citation:Dujic Z, Palada I, Valic Z, Duplancic D, Obad A, Wisløff U, Brubakk A: Exogenous nitric oxide and bubble formation in divers. Med Sci Sports Exerc. 2006 Aug;38(8):1432-5. Lead author's name and e-mail: Zeljko Dujic, [| zdujic@bsb.mefst.hr]
Three-part Clinical Question: Among divers, would a short lasting NO-donor, nitroglycerine, reduce bubble formation after standard dives and decompression in man? Search Terms: Decompression Illness, Nitric Oxide, Diving
The Study:Non-blinded randomised trial with intention-to-treat. The Study Patients: 16 experienced divers. All fit and well. Control groups (N =16; 16 analysed): 10 Wet divers, 30 msw, swimming for 500 m. Bottom time 30 min with 3 min safety stop at 3 msw. 6 Dry divers, 18 msw, bottom time 75 min with stop at 3 msw for 7 minutes. Experimental groups (N =16; 16 analysed): As above preceded by 0.4 mg of nitroglycerine oral spray 30 min before diving.
The Evidence:
| Measure | Control Group | Nitroglycerine Group | Difference | 95% CI | ||
| ^ | Mean | SD | Mean | SD | ^ | ^ |
| Wet dive (bubbles/cm²) N 10 | 0.87 | 1.3 | 0.32 | 0.7 | 0.55 | -0.43 to 1.53 |
| Dry dive (bubbles/cm²) N 6 | 0.12 | 0.23 | 0.03 | 0.03 | 0.09 | -0.12 to 0.30 |
| Wet divers N10 | Dry divers N6 | |||||
| Wet vs. dry dive (bubbles/cm²) | 0.87 | 1.3 | 0.12 | 0.23 | 0.75 | -0.42 to 1.92 |
Comments: 1. The allocation to wet versus dry diving was randomised, but all divers then did the control dive followed by the nitroglycerine dive. 2. Our table reflects an independent t-test for the significance of the difference for the NO/no-NO comparisons. The authors used a paired t-test for these sequential dives and reported a P-value of 0.04 (wet dives) and 0.05 (dry dives). 3. Results may not extrapolate to all divers - only divers with "considerable experience of air and oxygen diving" were eligible. 4. No side-effects measured.
Appraised by: Ing Han Gho and Mike Bennett, Prince of Wales Hospital, Sydney; Friday, 1 August 2008Email: [| m.bennett@unsw.edu.au] Kill or Update By: December 2021
