Lisa N. Sharwood

High-Concentration Nitrous Oxide for Procedural Sedation in Children: Adverse Events and Depth of Sedation

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 childrens 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.

No improvement in neurocognitive outcomes after off-pump versus on-pump coronary revascularisation: a meta-analysis

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.

Limited analgesic efficacy of nitrous oxide for painful procedures in children

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.

Assessing sleepiness and sleep disorders in Australian long-distance commercial vehicle drivers: self-report versus an "at home" monitoring device

STUDY OBJECTIVES As obstructive sleep apnea (OSA) is associated with a higher risk of motor vehicle crashes, there is increasing regulatory interest in the identification of commercial motor vehicle (CMV) drivers with this condition. This study aimed to determine the relationship between subjective versus objective assessment of OSA in CMV drivers. DESIGN Cross-sectional survey. SETTINGS Heavy vehicle truck stops located across the road network of 2 large Australian states. PARTICIPANTS A random sample of long distance commercial vehicle drivers (n = 517). INTERVENTIONS None. MEASUREMENTS AND RESULTS Drivers were interviewed regarding their driving experience, personal health, shift schedules, payments, and various questions on sleep and tiredness in order to describe their sleep health across a range of variables. In addition, home recordings using a flow monitor were used during one night of sleep. Only 4.4% of drivers reported a previous diagnosis of sleep apnea, while our at home diagnostic test found a further 41% of long-distance heavy vehicle drivers likely to have sleep apnea. The multivariable apnea prediction index, based on self-report measures, showed poor agreement with the home-monitor detected sleep apnea (AUC 0.58, 95%CI = 0.49-0.62), and only 12% of drivers reported daytime sleepiness (Epworth Sleepiness Scale score > 10). Thirty-six percent of drivers were overweight and a further 50% obese; 49% of drivers were cigarette smokers. CONCLUSIONS Sleep apnea remains a significant and unrecognized problem in CMV drivers, who we found to have multiple health risks. Objective testing for this sleep disorder needs to be considered, as symptom reports and self-identification appear insufficient to accurately identify those at risk.

Use of caffeinated substances and risk of crashes in long distance drivers of commercial vehicles: case-control study

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.

Topical lignocaine for pain relief in acute otitis media: results of a double-blind placebo-controlled randomised trial

Objective: Acute otitis media (AOM) is common in children, yet the optimal management of ear pain associated with AOM has not been well studied. We set out to determine the efficacy of topical aqueous 2% lignocaine eardrops compared with a placebo (saline) for pain relief of AOM in children. Design: Double-blind, randomised, placebo-controlled trial. Setting: Tertiary children’s hospital emergency department. Patients and interventions: Children aged between 3 and 17 years with earache and AOM without evidence of perforation were eligible. Patients were randomised to receive either 2% lignocaine or saline eardrops (placebo). Main outcome measures: Pain scores were measured before and after ear-drop administration. Patient and physician-interpreted pain scores were measured by using the Bieri faces pain scale and visual analogue scale at 10, 20 and 30 minutes. The primary outcome measure was reduction in patient-measured pain scores by 50% from the baseline. Secondary outcome measures were reduction in patient- measured pain scores by 25% or by at least two points. Telephone follow-up occurred after 1 day and 1 week. Analysis was by intention to treat. Results: 63 children (31 were treated with lignocaine, 32 with placebo) aged 3 to 12 years were enrolled. The groups were demographically and clinically similar, with similar proportions having received analgesia in the preceding 4 hours. Children receiving lignocaine showed significantly lower patient-measured pain scores with a reduction by 50% from baseline at 10 minutes (RR 2.06, 95% CI 1.03–4.11, p = 0.03) and 30 minutes (RR 1.44, 95% CI 1.07–1.93, p = 0.009) but not at 20 minutes (RR 1.35 95% CI 0.88–2.06). The response to lignocaine treatment showed significantly lower patient-measured pain scores for 25% reduction at all time points and for two-point reduction at 10 minutes and favoured lignocaine at 20 minutes and 30 minutes without reaching statistical significance. There were no serious adverse events during the 30 minute follow-up period. Conclusion: This study suggests that topical aqueous 2% lignocaine eardrops provide rapid relief for many young children presenting with ear pain attributed to AOM. The concurrent use of simple oral analgesia is a likely contributor to effective management of this painful childhood condition.

Pediatric procedural sedation with ketamine: time to discharge after intramuscular versus intravenous administration.

OBJECTIVES Ketamine is an attractive agent for pediatric procedural sedation. There are limited data on time to discharge comparing intramuscular (IM) vs. intravenous (IV) ketamine. The authors set out to determine whether IM or IV ketamine leads to quicker discharge from the emergency department (ED) and how side effect profiles compare. METHODS All patients who had received ketamine IM or IV at a tertiary childrens hospital ED during the 3-year study period (2004-2007) were identified. Prospective sedation registry data, retrospective medical records, and administrative data were reviewed for drug dosages, use of additional agents, time of drug administration to discharge, total ED time (triage to discharge), and adverse events. A subgroup analysis for patients requiring five or fewer sutures (short suture group) was performed. RESULTS A total of 229 patients were enrolled (60% male) with median age of 2.8 years (IQR =1.8-4.3 years) and median weight of 15.7 kg (range = 8.7-74 kg). Ketamine was most frequently employed for laceration repair (80%) and foreign body removal (9%). Overall, 48% received ketamine IM and 52% received it IV. In the short-suture subgroup, 52% received ketamine IM, while 48% received it IV. Multivariate linear regression analysis determined time from drug administration to patient discharge as 21 minutes shorter for IV compared with IM administration, adjusted for age and number of additional doses (R(2) = -0.35; 95% CI = -0.5 to -0.19; p < 0.001). Total time in the ED (triage to discharge) comparing IV versus IM administration, adjusting for age and gender and number of additional doses, was not significantly different (p = 0.16). In the short-suture subgroup, time to discharge from administration was also shorter in the IV ketamine group (R(2) = -0.454; 95%CI = -0.66 to -0.25; p < 0.001) but similar for total time in ED (p = 0.16). Overall, adverse events occurred in 35% (95% CI = 27% to 45%) of the IM group and 20% (95% CI = 13% to 28%) of the IV group (p = 0.01). Only one patient required brief bag-mask ventilation. CONCLUSIONS In this institution, time from drug injection to discharge was shorter in the IV compared to IM ketamine group, both overall and for the short-suture group. However, time from triage to discharge was similar.

The heavy vehicle study: a case-control study investigating risk factors for crash in long distance heavy vehicle drivers in Australia.

BackgroundHeavy vehicle transportation continues to grow internationally; yet crash rates are high, and the risk of injury and death extends to all road users. The work environment for the heavy vehicle driver poses many challenges; conditions such as scheduling and payment are proposed risk factors for crash, yet the precise measure of these needs quantifying. Other risk factors such as sleep disorders including obstructive sleep apnoea have been shown to increase crash risk in motor vehicle drivers however the risk of heavy vehicle crash from this and related health conditions needs detailed investigation.Methods and DesignThe proposed case control study will recruit 1034 long distance heavy vehicle drivers: 517 who have crashed and 517 who have not. All participants will be interviewed at length, regarding their driving and crash history, typical workloads, scheduling and payment, trip history over several days, sleep patterns, health, and substance use. All participants will have administered a nasal flow monitor for the detection of obstructive sleep apnoea.DiscussionSignificant attention has been paid to the enforcement of legislation aiming to deter problems such as excess loading, speeding and substance use; however, there is inconclusive evidence as to the direction and strength of associations of many other postulated risk factors for heavy vehicle crashes. The influence of factors such as remuneration and scheduling on crash risk is unclear; so too the association between sleep apnoea and the risk of heavy vehicle driver crash. Contributory factors such as sleep quality and quantity, body mass and health status will be investigated. Quantifying the measure of effect of these factors on the heavy vehicle driver will inform policy development that aims toward safer driving practices and reduction in heavy vehicle crash; protecting the lives of many on the road network.

The efficacy and effect of opioid analgesia in undifferentiated abdominal pain in children: a review of four studies

Introduction:  The question of whether opioid analgesia should be given in patients with undifferentiated acute abdominal pain has been characterized by concerns about its efficacy and that signs used to determine accurate diagnosis may be masked by the drug. The objective of this review is to critically analyze pertinent pediatric randomized controlled studies considering this issue.

Early decompression following cervical spinal cord injury: examining the process of care from accident scene to surgery

Early decompression may improve neurological outcome after spinal cord injury (SCI), but is often difficult to achieve because of logistical issues. The aims of this study were to 1) determine the time to decompression in cases of isolated cervical SCI in Australia and New Zealand and 2) determine where substantial delays occur as patients move from the accident scene to surgery. Data were extracted from medical records of patients aged 15-70 years with C3-T1 traumatic SCI between 2010 and 2013. A total of 192 patients were included. The median time from accident scene to decompression was 21 h, with the fastest times associated with closed reduction (6 h). A significant decrease in the time to decompression occurred from 2010 (31 h) to 2013 (19 h, p = 0.008). Patients undergoing direct surgical hospital admission had a significantly lower time to decompression, compared with patients undergoing pre-surgical hospital admission (12 h vs. 26 h, p < 0.0001). Medical stabilization and radiological investigation appeared not to influence the timing of surgery. The time taken to organize the operating theater following surgical hospital admission was a further factor delaying decompression (12.5 h). There was a relationship between the timing of decompression and the proportion of patients demonstrating substantial recovery (2-3 American Spinal Injury Association Impairment Scale grades). In conclusion, the time of cervical spine decompression markedly improved over the study period. Neurological recovery appeared to be promoted by rapid decompression. Direct surgical hospital admission, rapid organization of theater, and where possible, use of closed reduction, are likely to be effective strategies to reduce the time to decompression.