BACKGROUND AND OBJECTIVE: An estimated 150 million people worldwide use cannabis. The effect of cannabis on anaesthetic requirements in humans does not appear to have been studied. METHODS: In this prospective, randomized, single-blinded study, 30 male patients using cannabis more than once per week (group C) and 30 nonusers (group NC), aged 18-50 years, were induced with propofol 1.5, 2, 2.5, 3 or 3.5 mg kg. Additional doses were given when required. The primary outcome was the 50% effective dose of propofol and successful induction was determined by loss of consciousness with a bispectral index value of less than 60 and satisfactory insertion of a laryngeal mask. Propofol requirements to achieve these outcomes were recorded. RESULTS: The dose required to achieve the target bispectral index value was not significantly higher in group C, but group C required a significantly higher propofol dose to achieve laryngeal mask insertion (314.0 +/- 109.3 vs. 263.2 +/- 69.5 mg, P < 0.04). The estimated effective propofol induction dose in 50-95% of patients did not significantly differ between groups. CONCLUSION: We conclude that cannabis use increases the propofol dose required for satisfactory clinical induction when inserting a laryngeal mask.
RCT Entities:
BACKGROUND AND OBJECTIVE: An estimated 150 million people worldwide use cannabis. The effect of cannabis on anaesthetic requirements in humans does not appear to have been studied. METHODS: In this prospective, randomized, single-blinded study, 30 male patients using cannabis more than once per week (group C) and 30 nonusers (group NC), aged 18-50 years, were induced with propofol 1.5, 2, 2.5, 3 or 3.5 mg kg. Additional doses were given when required. The primary outcome was the 50% effective dose of propofol and successful induction was determined by loss of consciousness with a bispectral index value of less than 60 and satisfactory insertion of a laryngeal mask. Propofol requirements to achieve these outcomes were recorded. RESULTS: The dose required to achieve the target bispectral index value was not significantly higher in group C, but group C required a significantly higher propofol dose to achieve laryngeal mask insertion (314.0 +/- 109.3 vs. 263.2 +/- 69.5 mg, P < 0.04). The estimated effective propofol induction dose in 50-95% of patients did not significantly differ between groups. CONCLUSION: We conclude that cannabis use increases the propofol dose required for satisfactory clinical induction when inserting a laryngeal mask.
Authors: Karim S Ladha; Varuna Manoo; Ali-Faizan Virji; John G Hanlon; Alexander Mclaren-Blades; Akash Goel; Duminda N Wijeysundera; Lakshmi P Kotra; Carlos Ibarra; Marina Englesakis; Hance Clarke Journal: Cannabis Cannabinoid Res Date: 2019-12-06
Authors: Tsun Yee Law; Jennifer Kurowicki; Samuel Rosas; Karim Sabeh; Spencer Summers; Zachary Hubbard; Martin Roche Journal: J Long Term Eff Med Implants Date: 2018