title: Isoproterenol accelerates decompression sickness and death after saturation dives in swine.
abstract: BACKGROUND
  Disabled submarine (DISSUB) survivors are expected to achieve inert gas tissue saturation that would likely cause severe decompression sickness (DCS). Rescue procedures in a DISSUB scenario cannot accommodate a staged decompression and the availability of recompression treatment chambers is limited. Alternatives to the standard recompression procedures for treating DCS are needed. Experimentally, isoproterenol has successfully addressed many underlying physiological concerns expected to result in cardiopulmonary DCS in this group.
  
  
  OBJECTIVE
  We hypothesized that isoproterenol would reduce the incidence of cardiopulmonary DCS in a saturation dropout model.
  
  
  METHODS
  Yorkshire swine (21.8 +/- 1.68 kg) were fitted with an external jugular catheter and compressed to 4.33 ATA in a dry chamber for 22 h. They were infused with isoproterenol (0.002 mg x kg(-1)) while still at depth and returned to the surface without decompression stops. They received additional infusions every 10 min throughout a 2-h observation period. Signs of DCS were recorded to the nearest minute.
  
  
  RESULTS
  Isoproterenol administration resulted in a significant increase in the incidence of severe cardiopulmonary DCS (13/34 control vs. 12/18 isoproterenol) and death from DCS (10/34 control vs. 11/18 isoproterenol). There was no difference in the incidence of severe neurological DCS.
  
  
  CONCLUSIONS
  Administering isoproterenol as an intervention/treatment for DCS significantly increases the risk of cardiopulmonary DCS and death following saturation dropout in 20-kg swine. As an adjunctive therapy or alternative to staged decompression, isoproterenol in the dose regimen delivered here is not expected to improve outcome in a DISSUB mass casualty scenario.
authors.affiliation: Naval Medical Research Center, Silver Spring, MD 20910-7500, USA.
authors.forename: John W
authors.initials: JW
authors.lastname: Nelson
authors.forename: J Kent
authors.initials: JK
authors.lastname: Werner
authors.forename: J Robert
authors.initials: JR
authors.lastname: Burge
mesh_terms: D000318:Adrenergic beta-Agonists / Q000633:toxicity*; D000818:Animals; D003665:Decompression Sickness / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology; D004242:Diving / Q000009:adverse effects*; D007545:Isoproterenol / Q000633:toxicity*; D008297:Male; D018709:Statistics, Nonparametric; D013552:Swine
chemical_list: D000318:Adrenergic beta-Agonists; D007545:Isoproterenol