OBJECTIVE. Nitrous oxide is an attractive agent for procedural sedation and analgesia in the emergency department; however, there are limited safety data for high-concentration continuous-flow nitrous oxide (50%–70%) and its use in young children. We set out to characterize the depth of sedation and incidence of adverse events associated with various concentrations of nitrous oxide used in a pediatric emergency department. METHODS. This was a prospective observational study of nitrous oxide use for procedural sedation and analgesia in a tertiary children's hospital emergency department. Nitrous oxide concentration, adverse events, and sedation depth were recorded. Adverse events were categorized as mild or serious. Sedation depth was recorded on a sedation scale from 0 to 6. RESULTS. A total of 762 patients who were aged 1 to 17 years received nitrous oxide during the 2-year study period. A total of 548 (72%) received nitrous oxide 70%, and 101 (13%) received nitrous oxide 50%. Moderate or deep sedation with scores of ≤2 occurred in 3% of patients who had received nitrous oxide 70% and no patients who had received nitrous oxide 50%. Mean sedation scores were 4.4 at nitrous oxide 70% and 4.6 at nitrous oxide 50%. Sixty-three (8.3%) patients sustained 70 mild and self-resolving adverse events, most of which were vomiting (5.7%); 2 (0.2%) patients had serious adverse events. There was no significant difference in adverse events rates between nitrous oxide 70% (8.4%) and nitrous oxide 50% (9.9%). There was no significant difference in the percentage of deep sedation when children who were ≤3 years of age (2.9%) were compared with older children (2.8%). CONCLUSIONS. In this largest prospective emergency department series, high-concentration continuous-flow nitrous oxide (70%) was found to be a safe agent for procedural sedation and analgesia when embedded in a comprehensive sedation program. Nitrous oxide also seems safe in children aged 1 to 3 years.

The popularity of off-pump (beating heart) coronary artery bypass grafting (CABG) was initially stimulated by numerous theoretical benefits including lower incidence of stroke and neurocognitive dysfunction. With a postoperative stroke rate of less than 1% for elective CABG, it has been very difficult to demonstrate any significant differences in this outcome between techniques. However, changes in neurocognitive function are more common in the postoperative setting and thus provide greater power for demonstrating improvement with changes in surgical technique. The aim of this meta-analysis was to assess whether there were significant differences in neurocognitive outcomes in patients after undergoing off-pump versus on-pump CABG. A database search for prospective randomised controlled trials of off-pump versus on-pump CABG in any language was conducted. Eight trials incorporating 892 patients fulfilled all the inclusion criteria for reporting of neurocognitive outcomes, and were able to be included in this meta-analysis. Sufficient data were available across the seven studies to combine results for five neurocognitive tests (Rey Auditory Verbal Learning, Grooved Pegboard, Trail A and B, and Digit Symbol). Overall there were no convincing differences in outcomes in neurocognitive testing between off-pump and on-pump CABG groups. The results of this meta-analysis show that there are no significant neurocognitive benefits when comparing off-pump versus on-pump CABG.

Heavy-vehicle driving involves a challenging work environment and a high crash rate. We investigated the associations of sleepiness, sleep disorders, and work environment (including truck characteristics) with the risk of crashing between 2008 and 2011 in the Australian states of New South Wales and Western Australia. We conducted a case-control study of 530 heavy-vehicle drivers who had recently crashed and 517 heavy-vehicle drivers who had not. Drivers' crash histories, truck details, driving schedules, payment rates, sleep patterns, and measures of health were collected. Subjects wore a nasal flow monitor for 1 night to assess for obstructive sleep apnea. Driving schedules that included the period between midnight and 5:59 am were associated with increased likelihood of crashing (odds ratio = 3.42, 95% confidence interval: 2.04, 5.74), as were having an empty load (odds ratio = 2.61, 95% confidence interval: 1.72, 3.97) and being a less experienced driver (odds ratio = 3.25, 95% confidence interval: 2.37, 4.46). Not taking regular breaks and the lack of vehicle safety devices were also associated with increased crash risk. Despite the high prevalence of obstructive sleep apnea, it was not associated with the risk of a heavy-vehicle nonfatal, nonsevere crash. Scheduling of driving to avoid midnight-to-dawn driving and the use of more frequent rest breaks are likely to reduce the risk of heavy-vehicle nonfatal, nonsevere crashes by 2–3 times.

Objective To determine whether there is an association between use of substances that contain caffeine and the risk of crash in long distance commercial vehicle drivers. Design Case-control study. Setting New South Wales (NSW) and Western Australia (WA), Australia. Participants 530 long distance drivers of commercial vehicles who were recently involved in a crash attended by police (cases) and 517 control drivers who had not had a crash while driving a commercial vehicle in the past 12 months. Main outcome measure The likelihood of a crash associated with the use of substances containing caffeine after adjustment for factors including age, health disorders, sleep patterns, and symptoms of sleep disorders as well as exposures such as kilometres driven, hours slept, breaks taken, and night driving schedules. Results Forty three percent of drivers reported consuming substances containing caffeine, such as tea, coffee, caffeine tablets, or energy drinks for the express purpose of staying awake. Only 3% reported using illegal stimulants such as amphetamine (“speed”); 3,4 methylenedioxymethamphetamine (ecstasy); and cocaine. After adjustment for potential confounders, drivers who consumed caffeinated substances for this purpose had a 63% reduced likelihood of crashing (odds ratio 0.37, 95% confidence interval 0.27 to 0.50) compared with drivers who did not take caffeinated substances. Conclusions Caffeinated substances are associated with a reduced risk of crashing for long distance commercial motor vehicle drivers. While comprehensive mandated strategies for fatigue management remain a priority, the use of caffeinated substances could be a useful adjunct strategy in the maintenance of alertness while driving.

Study objective: Nitrous oxide (N₂O) is an attractive agent for procedural analgesia and sedation of children in the emergency department (ED). Despite increasing use, efficacy data for painful procedures are limited. This study aimed to determine pain scores during ED procedural sedation with N₂O in the ED setting. Methods: Prospective observational study of N₂O use as a sole agent for procedural analgesia at a tertiary children’s hospital ED. Pain scores were obtained from patients and parents using visual analogue or faces scales, as appropriate. Parent and staff satisfaction with sedation and analgesia were assessed. Results: 124 children aged 1–17 years (mean 8.1) underwent procedural analgesia with N₂O for 131 procedures. Most procedures were orthopaedic (44%) or laceration repair (30%). In 51% of patients (95% CI 42% to 60 to 23%) pain scores remained unchanged and in 34% (95% CI 26% to 43%) pain scores increased. Overall, 34% (95% CI 26% to 43%) patients had intraprocedural scores of 50 mm or greater and 21% (95% CI 14% to 29%) had pain scores of 70 mm or greater. Some procedures such as fracture reduction had a larger proportion of patients with high pain scores or 50 mm or greater (45%) and 70 mm or greater (29%). Staff rated both sedation and analgesia as “adequate” in 92%. Parents contacted in follow-up were satisfied or very satisfied with procedures in 96% and sedations in 93%. Conclusion: Data indicate that parents and staff are generally satisfied with N₂O for procedural use in the ED. The efficacy of N₂O as a sole agent in very painful procedures is limited.

S and full research articles published in SLEEP, the official journal of the APSS. Sleep and sleep disorder scientific findings.