title: Nitrox permits direct exit for attendants during extended hyperbaric oxygen treatment.
abstract: BACKGROUND
  Intermittent breathing of oxygen-enriched air, nitrox (1:1 air:oxygen, 60.5% O2), for attendants in multiplace hyperbaric chambers should enable treatment protocols (HOPAN - hyperbaric oxygen protocol attendants' nitrox) of up to 200 minutes at 2.8 atmospheres absolute (ATA), while retaining the option of a direct decompression and exit.
  
  
  METHODS
  HOPAN with cycles of 15 minutes of nitrox breathing followed by 10 minutes of chamber air for attendants were occasionally used from 2007-2009. HOPAN vs. LTP (local treatment protocols) were evaluated via an anonymous enquiry among attendants; patients' medical records were followed six months post-HBO2 treatment (HBO2T).
  
  
  RESULTS
  88 HOPANs, with 59 chamber attendants assisting 30 patients, were documented. HOPAN duration ranged from 55-167 minutes (median 140 minutes). 31/59 attendants answered the enquiry. Perceived comfort of each protocol (HOPAN vs. LTP) by attendants was reported as equal. Symptoms, both minor (parestesias) and severe (joint pain), were reported in connection with LTP, while only one occurrence (mild joint pain) was reported in connection with HOPAN. No complications were documented among the attendants or the patients. It is suggested that nitrox breathing for chamber attendants provide flexible HBO2T for patients at 2.8 ATA for up to 200 minutes within no-decompression limits, facilitating future studies of HBO2T dosage.
authors.affiliation: Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden. agneta.larsson@ki.se
authors.forename: Agneta C
authors.initials: AC
authors.lastname: Larsson
authors.forename: Johan
authors.initials: J
authors.lastname: Uusijärvi
authors.forename: Oskar
authors.initials: O
authors.lastname: Frånberg
authors.forename: Staffan
authors.initials: S
authors.lastname: Eksborg
authors.forename: Peter
authors.initials: P
authors.lastname: Lindholm
mesh_terms: D000328:Adult; D001273:Atmosphere Exposure Chambers; D002985:Clinical Protocols / Q000592:standards; D003665:Decompression Sickness / Q000209:etiology*; D005240:Feasibility Studies; D005260:Female; D006282:Health Personnel; D006801:Humans; D006931:Hyperbaric Oxygenation / Q000009:adverse effects / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009584:Nitrogen / Q000008:administration & dosage* / Q000009:adverse effects; D009784:Occupational Diseases / Q000209:etiology*; D016273:Occupational Exposure / Q000706:statistics & numerical data; D010100:Oxygen / Q000008:administration & dosage* / Q000009:adverse effects; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: C041364:nitrox; D009584:Nitrogen; D010100:Oxygen