title: Effect of caffeine and taurine on simulated laparoscopy performed following sleep deprivation.
abstract: BACKGROUND
  Sleep deprivation affects surgical performance and has the potential to endanger patient safety. Pharmacological stimulants may counter this consequence of long working hours. This study aimed to investigate whether commonly available stimulants can counter the effects of fatigue on technical and neurocognitive skill.
  
  
  METHODS
  This was a single-blind crossover study of surgical novices trained to proficiency on the Minimally Invasive Surgical Trainer-Virtual Reality laparoscopic simulator. Participants were acutely sleep-deprived three times each, followed by administration of either placebo, 150 mg caffeine, or 150 mg caffeine combined with 2 g taurine before simulated laparoscopy. Outcome measures were: laparoscopic psychomotor skill, cognitive performance and the Stanford Sleepiness Scale (range 1-7). Rested baselines were gathered following completion of test sessions.
  
  
  RESULTS
  Baseline performance was recorded for 18 participants in the rested state. Sleep-deprived participants receiving the placebo took longer (median 41 versus 35 s; P = 0·016), were less economical with movement (3·25 versus 2·95 m; P = 0·016) and made more errors (66 versus 59; P = 0·021) on the laparoscopic task compared with the rested state. Caffeine restored psychomotor skills to baseline for time taken (37 versus 35 s; P = 0·101), although the number of errors remained significantly greater than in the rested state (63 versus 59; P = 0·046). Sleep-deprived subjects receiving placebo had slower reaction times (377 versus 299 ms; P = 0·008) and a higher score on the Stanford Sleepiness Scale (6 versus 2 points; P = 0·001) than rested surgeons. Negative effects of sleep deprivation on reaction time were reversed when caffeine (307 ms versus 299 ms in rested state; P = 0·214) or caffeine plus taurine (326 versus 299 ms; P = 0·110) was administered. Subjective sleepiness was also improved, but not to baseline levels.
  
  
  CONCLUSIONS
  Sleep deprivation affects laparoscopic psychomotor skills, reaction time and subjective measures of sleepiness in novice surgical subjects. Caffeine and taurine restore simulated laparoscopic performance to rested levels, but do not reduce errors.
authors.affiliation: Department of Biosurgery and Surgical Technology, Imperial College London, London, UK. rajesh.aggarwal@imperial.ac.uk
authors.forename: R
authors.initials: R
authors.lastname: Aggarwal
authors.forename: A
authors.initials: A
authors.lastname: Mishra
authors.forename: P
authors.initials: P
authors.lastname: Crochet
authors.forename: P
authors.initials: P
authors.lastname: Sirimanna
authors.forename: A
authors.initials: A
authors.lastname: Darzi
mesh_terms: D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003071:Cognition / Q000502:physiology; D003198:Computer Simulation; D018592:Cross-Over Studies; D013502:General Surgery / Q000193:education; D006801:Humans; D010535:Laparoscopy / Q000592:standards*; D011597:Psychomotor Performance / Q000187:drug effects*; D016037:Single-Blind Method; D012892:Sleep Deprivation / Q000503:physiopathology*; D013654:Taurine / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D013654:Taurine; D002110:Caffeine