Colin Sugden

Effect of Pharmacological Enhancement on the Cognitive and Clinical Psychomotor Performance of Sleep-Deprived Doctors: A Randomized Controlled Trial

Objectives: To investigate the effect of modafinil 200 mg on the performance of a cohort of healthy male doctors after 1 night of supervised sleep deprivation. Summary Background Data: Sleep-deprived and fatigued doctors pose a safety risk to themselves and their patients. Yet, because of the around-the-clock nature of medical practice, doctors frequently care for patients after periods of extended wakefulness or during circadian troughs. Studies suggest that a group of substances may be capable of safely and effectively reversing the effects of fatigue. However, little work has been done to investigate their role within our profession. Methods: We conducted a parallel, double-blind, randomized, and placebo-controlled study to investigate the effect of pharmacological enhancement on performance doctors. Thirty-nine healthy male resident doctors received either lactose placebo (n = 19) or modafinil 200 mg (n = 20) after 1 night of sleep deprivation. A selection of CANTAB neuropsychological tests was used to assess higher cognitive function. Clinical psychomotor performance was assessed using the Minimally Invasive Surgical Trainer Virtual Reality. Assessments were carried out between 6.00 AM and approximately 8.00 AM. Results: Modafinil improved performance on tests of higher cognitive function; participants in the modafinil group worked more efficiently when solving working memory (F 1,38 = 5.24, P = 0.028) and planning (F 1,38 = 4.34, P = 0.04) problems, were less-impulsive decision makers (F 1,37 = 6.76, P = 0.01), and were more able to flexibly redirect their attention (F 1,38 = 4.64, P = 0.038). In contrast, no improvement was seen in tests of clinical psychomotor performance. Conclusions: Our results suggest that fatigued doctors might benefit from pharmacological enhancement in situations that require efficient information processing, flexible thinking, and decision making under time pressure. However, no improvement is likely to be seen in the performance of basic procedural tasks.

The development of a virtual reality training curriculum for colonoscopy.

Objectives: The development of a structured virtual reality (VR) training curriculum for colonoscopy using high-fidelity simulation. Background: Colonoscopy requires detailed knowledge and technical skill. Changes to working practices in recent times have reduced the availability of traditional training opportunities. Much might, therefore, be achieved by applying novel technologies such as VR simulation to colonoscopy. Scientifically developed device-specific curricula aim to maximize the yield of laboratory-based training by focusing on validated modules and linking progression to the attainment of benchmarked proficiency criteria. Methods: Fifty participants comprised of 30 novices (<10 colonoscopies), 10 intermediates (100 to 500 colonoscopies), and 10 experienced (>500 colonoscopies) colonoscopists were recruited to participate. Surrogates of proficiency, such as number of procedures undertaken, determined prospective allocation to 1 of 3 groups (novice, intermediate, and experienced). Construct validity and learning value (comparison between groups and within groups respectively) for each task and metric on the chosen simulator model determined suitability for inclusion in the curriculum. Results: Eight tasks in possession of construct validity and significant learning curves were included in the curriculum: 3 abstract tasks, 4 part-procedural tasks, and 1 procedural task. The whole-procedure task was valid for 11 metrics including the following: “time taken to complete the task” (1238, 343, and 293 s; P < 0.001) and “insertion length with embedded tip” (23.8, 3.6, and 4.9 cm; P = 0.005). Learning curves consistently plateaued at or beyond the ninth attempt. Valid metrics were used to define benchmarks, derived from the performance of the experienced cohort, for each included task. Conclusions: A comprehensive, stratified, benchmarked, whole-procedure curriculum has been developed for a modern high-fidelity VR colonoscopy simulator.

Pharmacological enhancement of performance in doctors.

The benefits have not been proved, and more evidence is needed

A randomized controlled trial evaluating endoscopic and laparoscopic training in skills transfer for novices performing a simulated NOTES task.

Background. The NOSCAR white paper lists training as an important step to the safe clinical application of natural orifice translumenal endoscopic surgery (NOTES). The aim of this randomized controlled trial was to evaluate whether training novices in either a laparoscopic or endoscopic simulator curriculum would affect performance in a NOTES simulator task. Methods. A total of 30 third-year medical undergraduates were recruited. They were randomized to 3 groups: no training (control; n = 10), endoscopy training on a validated colonoscopy simulator protocol (n = 10), and training on a validated laparoscopy simulator curriculum (n = 10). All participants subsequently completed a simulated NOTES task, consisting of 7 steps, on the ELITE (endoscopic-laparoscopic interdisciplinary training entity) model. Performance was assessed as time taken to complete individual steps, overall task time, and number of errors. Results. The endoscopy group was significantly faster than the control group at accessing the peritoneal cavity through the gastric incision (median 27 vs 78 s; P = .015), applying diathermy to the base of the appendix (median 103.5 vs 173 s; P = .014), and navigating to the gallbladder (median 76 vs 169.5 s; P = .049). Endoscopy participants completed the full NOTES procedure in a shorter time than the laparoscopy group (median 863 vs 2074 s; P < .001). Conclusion. This study highlights the importance of endoscopic training for a simulated NOTES task that involves both navigation and resection with operative maneuvers. Although laparoscopic training confers some benefit for operative steps such as applying diathermy to the gallbladder fossa, this was not as beneficial as training in endoscopy.

Inhibitory control and perception of the future health in obese adolescents and normal weight adolescents

Abstract Background Childhood obesity tracks into adulthood, meaning obesogenic behaviours learned in early years are likely to be sustained throughout life. Studies of the neurocognitive mechanisms underlying obesity-related behaviours have implicated the role of impulsivity in weight gain. Food-related and physical-activity-related impulsive actions such as discounting of the future health benefits of present rewards or the inability to inhibit tempting unhealthy choices can lead to gradual weight gain. Impulsivity was compared in a group of obese and non-obese adolescents to test this hypothesis. Methods 47 obese adolescents (mean body-mass index [BMI] 33·22 [SD 8·0]) who attended a residential lifestyle summer camp with a mean age of 14·28 years (SD 1·7) were recruited with parental consent over two summers. A normal weight control group (BMI 20·6 [SD 2·3]) with a mean age of 13·83 years (SD 1·7) from a UK secondary school were used for comparison. Behavioural measures of impulsivity were tested using the stop signal reaction time (SSRT) as a marker of inhibitory control and the temporal discounting constant for monetary rewards. Self-reported scores of impulsivity using Cloningers junior temperament and character inventory were correlated with behavioural measures by use of a Spearmans correlation. Findings The non-obese group had better inhibitory control as measured by the SSRT with a mean value of 156·93 ms (SD 43·12) compared with the obese group with a mean value of 218·42 ms (80·48; p=0·0001). Additionally, SSRT direction errors were significantly higher in the obese adolescents (5·48 [SD 4·88]) than in normal weight individuals (2·88 [0·41]; p=0·0001), and the proportion of successful stops were significantly higher in the normal weight adolescents (0·49 [SD 0·1]) than in the obese group (0·53 [0·09]; p=0·02). Those who were obese (k=0·56 [SD 0·36]) were found to discount the future value of money significantly more than normal weight individuals (0·40 [0·29]; p=0·018) and scored higher on the novelty seeking subscale of the junior temperament and character inventory (r=0·23; p=0·03). Interpretation Impulsivity is a unitary construct, which is an independent predictor of BMI in adults and may act as a causal factor in adolescents. Obese adolescents exhibit poor inhibitory control and discount the future for monetary rewards more than their non-obese counterparts. In addition, there were greater response errors and a failure to stop during the no-go paradigm, suggesting the presence of either inattention or hyperactive traits in addition to impulsive behaviours in the obese group. The difference in socioeconomic status between both groups may be a confounding factor and was not available for analysis. Bias was reduced by ensuring all participants were in full-time education, matched for age, and masked to testing. Understanding of the neurocognitive mechanisms underlining obesogenic behaviours such as impulsivity is needed to improve existing interventions, through the development of novel methods to train self-control and self-efficacy as part of a personalised approach to weight reduction. Funding None.