title: The incidence of venous gas emboli in recreational diving.
abstract: From 1989-91, the Divers Alert Network monitored recreational divers for Doppler-detected venous gas emboli (VGE) and depth-time profiles following multi-day, repetitive, multi-level exposures. A Spencer score >0 occurred in 61 of 67 subjects (91%) and 205 of 281 dives (73%). No subject developed decompression sickness (DCS) on monitored days although 102 dives (36.3%) scored at Spencer Grades 2 or 3 (High Bubble Grade, HBG). We recorded the depth-time profiles with Suunto dive computers and estimated exposure severity with a probabilistic decompression algorithm. The HBG incidence increased 53% over the range of exposure severity (p < 0.001) in the divers, was approximately 20% higher for repetitive dives than for first dives, and decreased approximately 25% over the 6-8 days of multi-day diving (p < 0.001) suggesting a phenomenon similar to DCS adaptation. The observed HBG incidence was approximately 20% higher for males than females. Older male divers had a 25% increase in observed incidence of HBG while older female divers showed a 55% increase when compared to their younger counterparts.
authors.affiliation: Hyperbaric Center, Virginia Mason Medical Center, Seattle, WA, USA.
authors.forename: R G
authors.initials: RG
authors.lastname: Dunford
authors.forename: R D
authors.initials: RD
authors.lastname: Vann
authors.forename: W A
authors.initials: WA
authors.lastname: Gerth
authors.forename: C F
authors.initials: CF
authors.lastname: Pieper
authors.forename: K
authors.initials: K
authors.lastname: Huggins
authors.forename: C
authors.initials: C
authors.lastname: Wacholtz
authors.forename: P B
authors.initials: PB
authors.lastname: Bennett
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D003665:Decompression Sickness / Q000000981:diagnostic imaging / Q000453:epidemiology; D004242:Diving; D004618:Embolism, Air / Q000000981:diagnostic imaging / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D011336:Probability; D012737:Sex Factors; D013997:Time Factors; D014463:Ultrasonography