title: The effect of intravenous perfluorocarbon emulsions on whole-body oxygenation after severe decompression sickness.
abstract: BACKGROUND
  Decompression sickness (DCS) results from a decrease in ambient pressure leading to supersaturation of tissues with inert gas and bubble formation. Perfluorocarbons (PFCs) are able to dissolve vast amounts of non-polar gases. Intravenous (IV) PFC emulsions reduce both morbidity and mortality associated with DCS, but the mechanism of this protective effect has not yet been demonstrated.
  
  
  METHODS
  Juvenile Dorper-cross sheep (n = 31) were anaesthetised and instrumented for physiological monitoring, IV fluid administration and blood sampling. Animals were compressed in air in a hyperbaric chamber to 608 kPa for 30 minutes and then rapidly decompressed. Upon decompression, animals were randomly assigned to receive 6 mmol per L of PFC or saline over 10 minutes beginning immediately after chamber exit. Arterial and mixed venous bloods were drawn at 5, 10, 15, 30, 60 and 90 minutes to examine pH, partial pressures of oxygen and carbon dioxide, oxygen saturation and electrolytes.
  
  
  RESULTS
  Compared to saline, PFC administration increased arterial oxygen content (16.33 ± 0.28 vs. 14.68 ± 0.26 ml per dL, P < 0.0001), mixed venous oxygen content (12.56 ± 0.28 vs. 11.62 ± 0.26 ml per dL, P = 0.0167), oxygen delivery (14.83 ± 0.28 vs. 13.39 ± 0.26 mmol per L kg, P = 0.0003) and tissue oxygen consumption (3.30 ± 0.15 vs. 2.78 ± 0.13 mmol per L kg, P = 0.0149) but did not increase extraction ratio (0.22 ± 0.012 vs. 0.21 ± 0.011, P = 0.5343).
  
  
  CONCLUSIONS
  It is likely that the improved oxygenation explains, at least in part, the previously-observed therapeutic effects of PFCs in DCS.
authors.affiliation: Department of Anesthesiology,Virginia Commonwealth University Reanimation Engineering Shock Center, Richmond, Virginia 23298-0695, USA. crsmith@vcu.edu
authors.forename: Cameron R
authors.initials: CR
authors.lastname: Smith
authors.forename: J Travis
authors.initials: JT
authors.lastname: Parsons
authors.forename: Jiepei
authors.initials: J
authors.lastname: Zhu
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Spiess
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001273:Atmosphere Exposure Chambers; D002245:Carbon Dioxide / Q000097:blood*; D002302:Cardiac Output / Q000187:drug effects / Q000502:physiology; D003664:Decompression / Q000379:methods; D003665:Decompression Sickness / Q000097:blood* / Q000188:drug therapy* / Q000503:physiopathology; D004573:Electrolytes / Q000097:blood; D004655:Emulsions; D005466:Fluorocarbons / Q000008:administration & dosage / Q000494:pharmacology*; D007262:Infusions, Intravenous; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000187:drug effects* / Q000502:physiology; D010313:Partial Pressure; D011897:Random Allocation; D012756:Sheep; D012965:Sodium Chloride / Q000008:administration & dosage; D013997:Time Factors
chemical_list: D004573:Electrolytes; D004655:Emulsions; D005466:Fluorocarbons; D002245:Carbon Dioxide; D012965:Sodium Chloride; D010100:Oxygen