IngentaConnect Prophylactic High Dose Methylprednisolone Fails to Treat Severe D...

Abstract:

Dromsky DM, Weathersby PK, Fahlman A. Prophylactic high dose methylprednisolone fails to treat severe decompression sickness in swine. Aviat Space Environ Med 2003; 74:21-28.

Introduction: Controlled decompression from saturation conditions is not always an option, particularly in a disabled submarine scenario. Hypothesis: Prophylactic high dose methylprednisolone (MP) would improve outcome in severe cases of decompression sickness (DCS). Methods: Littermate pairs of male Yorkshire swine (n = 86, mean weight ± SE = 19.3 ± 0.2 kg) were randomized to one of three groups, then compressed on air to 4.3 ATA (33 msw) for 22 h and brought directly to surface pressure (1 ATA) at 0.9 ATA · min⁻¹. The MP-50 group received i.v. infusion of 50 mg · kg⁻¹ of MP dissolved in 60 cc normal saline (NS) immediately prior to the hyperbaric exposure. The NS group received 60 cc NS i.v. immediately prior to the hyperbaric exposure. The MP-10 group received i.v. infusion of 10 mg · kg⁻¹ MP dissolved in 60 cc NS during the hyperbaric exposure, 7 h before the decompression. Results: Outcomes of severe DCS and death were recorded. NS group: 14 DCS, 4 died; MP-50 group: 19 DCS, 12 died; MP-10 group: 19 DCS, 10 died. Compared with the NS group, logistic regression analysis suggested that animals in the MP-10 group were more likely to get severe DCS and to die (p < 0.01) and animals in the MP-50 group were more likely to die from their disease (p < 0.01). Discussion: Prophylactic high dose MP exerts no protective effect against severe DCS and actually worsens mortality in this model. An earlier group of untreated controls (UC, n = 44, 30 DCS, 11 died, mean weight ± SE = 19.9 ± 0.3 kg) exposed to the same profile was also available for analysis. Comparison of the UC and NS animals suggested that pre-dive NS treatment may protect against severe DCS.

Prophylactic High Dose Methylprednisolone Fails to Treat Severe Decompression Sickness in Swine