Local and national laparoscopic skill competitions: residents' opinions and impact on adoption of simulation-based training.

BACKGROUND: Dedicated practice using laparoscopic simulators improves operative performance. Yet, voluntary utilization is minimal. We hypothesized that skill competition between peers, at the local and national level, positively influences residents' use of laparoscopic simulators. METHODS: A web-based survey evaluated the relationship between Canadian General Surgery residents' use of laparoscopic simulation and participation in competition. Secondary outcomes assessed attitudes regarding simulation training, factors limiting use, and associations between competition level and usage. RESULTS: One hundred ninety (23%) of 826 potential participants responded. Eighty-three percent rated their laparoscopic abilities as novice or intermediate. More than 70% agreed that use of simulation practice improves intra-operative performance, and should be a mandatory component of training. However, 58% employed simulator practice less than once per month, and 18% never used a simulator. Sixty-five percent engaged in simulator training for 5 h or less over the preceding 6 months. Seventy-three percent had participated in laparoscopic skill competition. Of those, 51% agreed that competition was a motivation for simulation practice. No association was found between those with competition experience and simulator use. However, 83% of those who had competed nationally reported >5 h of simulator use in the previous 6 months compared to those with no competition experience (26%), local competition (40%), and local national-qualifying competition (23%) (p < 0.001). CONCLUSIONS: This study does not support the hypothesis that competition alone universally increases voluntary use of simulation-based training, with only the minority of individuals competing at the national level demonstrated significantly higher simulation use. However, simulation training was perceived as a valuable exercise. Lack of time and access to simulators, as opposed to lack of interest, were the most commonly reported to limited use.

A serious game skills competition increases voluntary usage and proficiency of a virtual reality laparoscopic simulator during first-year surgical residents' simulation curriculum.

BACKGROUND: The objective of this study was to assess the effect of a serious game skills competition on voluntary usage of a laparoscopic simulator among first-year surgical residents' standard simulation curriculum. METHODS: With research ethics board approval, informed consent was obtained from first-year surgical residents enrolled in an introductory surgical simulation curriculum. The class of 2013 served as a control cohort following the standard curriculum which mandates completion of six laparoscopic simulator skill tasks. For the 2014 competition cohort, the only change introduced was the biweekly and monthly posting of a leader board of the top three and ten fastest peg transfer times. Entry surveys were administered assessing attitudes towards simulation-based training and competition. Cohorts were observed for 5 months. RESULTS: There were 24 and 25 residents in the control and competition cohorts, respectively. The competition cohort overwhelmingly (76 %) stated that they were not motivated to deliberate practice by competition. Median total simulator usage time was 132 min (IQR = 214) in the competition cohort compared to 89 (IQR = 170) in the control cohort. The competition cohort completed their course requirements significantly earlier than the control cohort (χ 2 = 6.5, p = 0.01). There was a significantly greater proportion of residents continuing to use the simulator voluntarily after completing their course requirements in the competition cohort (44 vs. 4 %; p = 0.002). Residents in the competition cohort were significantly faster at peg transfer (194 ± 66 vs. 233 ± 53 s, 95 % CI of difference = 4-74 s; p = 0.03) and significantly decreased their completion time by 33 ± 54 s (95 % CI 10-56 s; paired t test, p = 0.007). CONCLUSIONS: A simple serious games skills competition increased voluntary usage and performance on a laparoscopic simulator, despite a majority of participants reporting they were not motivated by competition. Future directions should endeavour to examine other serious gaming modalities to further engage trainees in simulated skills development.

Association between Prehospital Time and Mortality following Blunt Thoracic Aortic Injuries.

BACKGROUND: Blunt thoracic aortic injuries (BTAIs) can be lethal, but advances in trauma systems and surgical care have helped reduce mortality. The purpose of this study is to investigate whether time from injury to presentation is associated with mortality following BTAI. METHODS: Using the Ontario Trauma Registry, all patients were identified who were hospitalized with BTAI between 1999 and 2009. Variables including age, sex, Injury Severity Score, Charlson comorbidity index, systolic blood pressure on admission, operative intervention, and time from injury to presentation were analyzed using multivariate logistic regression to determine independent predictors of mortality. RESULTS: We identified 264 cases of BTAI that survived until hospital admission. Of these, 220 patients had documented time from injury to presentation to hospital. Most, 68.2% (n = 150), presented within 60 min of injury. On adjusted multivariate analysis, a prehospital time of ≤60 min independently predicted higher mortality (odds ratio 0.27, 95% confidence interval 0.08-0.89, P = 0.03). Tight clustering was seen with prehospital time and mortality. CONCLUSIONS: Rather than reducing mortality as hypothesized, a shorter time between BTAI and hospital presentation (<60 min) is associated with increased mortality. This may be the result of selection bias with the quicker transport of more severely injured patients.

Predictors of Discharge Home after Blunt Traumatic Thoracic Aortic Injury.

BACKGROUND: Blunt traumatic thoracic aortic injury (BTAI) can be a highly lethal injury but in the last decade major advances have been made in diagnostic accuracy, injury grading, and therapy. Traditionally, emphasis has been on studying survival postinjury with a paucity of studies examining the discharge characteristics of patients that survive a BTAI. The purpose of this study is to define the epidemiology and predictors of disposition in patients with BTAI in a provincial database. METHODS: Using the Ontario Trauma Registry, all patients were identified who were hospitalized with a BTAI between 1999 and 2009. Trends in therapy and discharge disposition were determined. RESULTS: We identified 264 cases of BTAI. Of these, 157 were discharged from hospital with 36% (n = 56) going directly home and 64% (n = 101) going to continuing care facilities. There was no difference in disposition in those with BTAI treated operatively or nonoperatively (P = 0.48). In those that had repair of BTAI, there was no difference in discharge home between open and endovascular repair (P = 1.00). Univariate analyses identified younger age, male sex, lower injury severity score (ISS), and lower Charlson comorbidity indices as being predictors of discharge home. On adjusted multivariate regression analysis, lower ISS (odds ratio, 0.91; 95% confidence interval, 0.87-0.95; P < 0.001) was the only independent predictors of discharge home. CONCLUSIONS: Our findings suggest that the only independent predictor for discharge home for patients who survive is the overall severity of all their injuries irrespective of their condition on admission or management of their BTAI.

Priming of hypoxia-inducible factor by neuronal nitric oxide synthase is essential for adaptive responses to severe anemia.

Cells sense and respond to changes in oxygen concentration through gene regulatory processes that are fundamental to survival. Surprisingly, little is known about how anemia affects hypoxia signaling. Because nitric oxide synthases (NOSs) figure prominently in the cellular responses to acute hypoxia, we defined the effects of NOS deficiency in acute anemia. In contrast to endothelial NOS or inducible NOS deficiency, neuronal NOS (nNOS)(-/-) mice demonstrated increased mortality during anemia. Unlike wild-type (WT) animals, anemia did not increase cardiac output (CO) or reduce systemic vascular resistance (SVR) in nNOS(-/-) mice. At the cellular level, anemia increased expression of HIF-1α protein and HIF-responsive mRNA levels (EPO, VEGF, GLUT1, PDK1) in the brain of WT, but not nNOS(-/-) mice, despite comparable reductions in tissue PO(2). Paradoxically, nNOS(-/-) mice survived longer during hypoxia, retained the ability to regulate CO and SVR, and increased brain HIF-α protein levels and HIF-responsive mRNA transcripts. Real-time imaging of transgenic animals expressing a reporter HIF-α(ODD)-luciferase chimeric protein confirmed that nNOS was essential for anemia-mediated increases in HIF-α protein stability in vivo. S-nitrosylation effects the functional interaction between HIF and pVHL. We found that anemia led to nNOS-dependent S-nitrosylation of pVHL in vivo and, of interest, led to decreased expression of GSNO reductase. These findings identify nNOS effects on the HIF/pVHL signaling pathway as critically important in the physiological responses to anemia in vivo and provide essential mechanistic insight into the differences between anemia and hypoxia.

Reassessing the risk of hemodilutional anemia: Some new pieces to an old puzzle.

PURPOSE: Clinical studies demonstrate that anemia increases the risk of morbidity and mortality. Tissue hypoxia is an attractive but incompletely characterized candidate mechanism of anemia-induced organ injury. Physiological responses that optimize tissue oxygen delivery (nitric oxide synthase-NOS) and promote cellular adaptation to tissue hypoxia (hypoxia inducible factor-HIF) may reduce the risk of hypoxic organ injury and thereby improve survival during anemia. The presence of vascular diseases would likely impair the efficacy of these physiological mechanisms, increasing the risk of anemia-induced organ injury. In all cases, biological signals that indicate the activation of these adaptive mechanisms could provide an early and treatable warning signal of impending anemia-induced organ injury. Thus, we review the evidence for tissue hypoxia during acute hemodilutional anemia and also explore the novel hypothesis that methemoglobin, a measurable byproduct of increased NOS-derived nitric oxide (NO), may serve as a biomarker for "anemic stress". SOURCE: Published peer-reviewed studies provided the main source of information. Data from experimental studies were reassessed to derive the relationship between hemodilution (reduced hemoglobin concentration) and increased methemoglobin levels. PRINCIPAL FINDINGS: Active physiological mechanisms (sympathetic nervous system) are required to maintain optimal tissue oxygen delivery during hemodilutional anemia. Despite these responses, tissue hypoxia occurs during acute hemodilution, as demonstrated by a decrease in tissue PO(2) and an increase in hypoxic cellular responses (NOS, HIF). Optimal tissue oxygen delivery may be compromised further when cardiovascular responses are impaired. The positive correlation between decreased hemoglobin concentration (Hb) and an increase in methemoglobin levels in acutely anemic animals supports the hypothesis that anemia-induced increases in tissue NOS activity could promote methemoglobin formation. Methemoglobin may be a measurable byproduct of NO-mediated Hb oxidation. CONCLUSIONS: Evidence continues to demonstrate that anemia increases morbidity and mortality, possibly via hypoxic mechanisms. A potential strategy for assessing "anemic stress" was derived from experimental data based on a readily measurable biomarker, methemoglobin. New methods for measuring real-time hemoglobin and methemoglobin levels in patients may provide the basis to translate this idea into clinical practice. Further mechanistic studies are required to determine if the impact of reduced tissue oxygen delivery and activation of hypoxic cellular mechanism can be linked to measurable changes in biomarkers and clinical outcomes in acutely anemic patients.

A survey of primary care physician referral to bariatric surgery in Manitoba: access, perceptions and barriers.

BACKGROUND: There is an important disconnect between surgical programs and primary care physicians (PCP) in the delivery of bariatric care. The objective of this study is to assess PCP knowledge and perception of a provincial bariatric surgery program. METHODS: A 32-question, IRB approved, survey was developed by bariatric surgery experts and vetted by local PCPs. A single round of paper surveys was administered to 1,000 PCPs between July and September 2015. Continuous variables were assessed by t-test and categorical variables by Chi-square test. RESULTS: There were 131 survey responses (13.1%). Half (54.2%) of respondents did not feel equipped to counsel their patients on operative management strategies. PCPs counselled on average 11.6%±17.0% of their obese patients on bariatric surgery. Many respondents (58.3%) thought excess weight loss from gastric bypass was less than 40% and most believed there was less than 50% resolution of diabetes (62.4%), hypertension (72.3%), dyslipidemia (77.8%) and obstructive sleep apnea (60.6%). PCPs who referred patients to the bariatric program (71.8%) were more comfortable counselling their patients on bariatric surgery options (56.8% vs. 17.1%, P<0.001) and were more comfortable with post-operative care (67.4% vs. 38.2%, P=0.004). Additionally, these PCPs estimated higher rates of diabetes and hypertension resolution post-bariatric surgery. The predominant perceived barrier to accessing bariatric surgery was wait times (33.3%). CONCLUSIONS: PCPs appear to underestimate the efficacy of bariatric surgery in the treatment of obesity and feel ill-equipped to counsel patients. Further education related to bariatric surgery may improve PCP comfort in counselling and long-term follow-up.

Outcomes of extracorporeal, transumbilical versus intracorporeal laparoscopic appendectomy for acute uncomplicated appendicitis in children and adolescents: A retrospective observational cohort study.

BACKGROUND: An extracorporeal (ECA), transumbilical appendectomy has been proposed as a treatment for appendicitis. This study assessed the 30-day perioperative outcomes and cost between ECA and traditional intracorporeal (ICA) techniques for acute uncomplicated appendicitis. METHODS: IRB approval was obtained for this retrospective cohort study of acute uncomplicated appendicitis in children aged 4 to 17 between April 2014 and April 2017. Patients were grouped based on ICA versus ECA. Operative time, length of stay, and complication rates were recorded. RESULTS: A total of 289 patients were included, and of these 217 underwent ICA, and 72 underwent ECA. Median weight-for-age percentile was the only demographic characteristic different between groups (ECA 50 [0.1-100] vs. ICA 71 [0-100]; p < 0.01). Median operative time was significantly shorter in the ECA group (21.0 min [8.0-61.0] vs. 38.0 min [19.0-87.0]; p < 0.0001). Length of stay and complication rates were similar between groups. The median per case cost was significantly lower in the ECA group (CAD$ 593.05 range: 499.70-900.81 vs. CAD$ 858.78 range: 490.36-1106.29; p < 0.001). CONCLUSIONS: Extracorporeal transumbilical laparoscopic appendectomy is associated with shorter operative times and no increased risk of 30-day postoperative complications in children and adolescents. This offers a new operative approach that may reduce hospital cost and resources. LEVEL OF EVIDENCE: III.

Metoprolol impairs resistance artery function in mice.

Acute ß-blockade with metoprolol has been associated with increased mortality by undefined mechanisms. Since metoprolol is a relatively high affinity blocker of ß(2)-adrenoreceptors, we hypothesized that some of the increased mortality associated with its use may be due to its abrogation of ß(2)-adrenoreceptor-mediated vasodilation of microvessels in different vascular beds. Cardiac output (CO; pressure volume loops), mean arterial pressure (MAP), relative cerebral blood flow (rCBF; laser Doppler), and microvascular brain tissue Po(2) (G2 oxyphor) were measured in anesthetized mice before and after acute treatment with metoprolol (3 mg/kg iv). The vasodilatory dose responses to ß-adrenergic agonists (isoproterenol and clenbuterol), and the myogenic response, were assessed in isolated mesenteric resistance arteries (MRAs; ∼200-µm diameter) and posterior cerebral arteries (PCAs ∼150-µm diameter). Data are presented as means ± SE with statistical significance applied at P < 0.05. Metoprolol treatment did not effect MAP but reduced heart rate and stroke volume, CO, rCBF, and brain microvascular Po(2), while concurrently increasing systemic vascular resistance (P < 0.05 for all). In isolated MRAs, metoprolol did not affect basal artery tone or the myogenic response, but it did cause a dose-dependent impairment of isoproterenol- and clenbuterol-induced vasodilation. In isolated PCAs, metoprolol (50 µM) impaired maximal vasodilation in response to isoproterenol. These data support the hypothesis that acute administration of metoprolol can reduce tissue oxygen delivery by impairing the vasodilatory response to ß(2)-adrenergic agonists. This mechanism may contribute to the observed increase in mortality associated with acute administration of metoprolol in perioperative patients.

Functional contribution of specific brain areas to absence seizures: role of thalamic gap-junctional coupling.

The synchronized discharges typical of seizures have a multifactorial origin at molecular, cellular and network levels. During recent years, the functional role of gap-junctional coupling has received increased attention as a mechanism that may participate in seizure generation. We have investigated the possible functional roles of thalamic and hippocampal gap-junctional communication (GJC) in the generation of spike-and-wave discharges in a rodent model of atypical absence seizures. Seizures in this model spread throughout limbic, thalamic and neocortical areas. Rats were chronically implanted with cannulae to deliver drugs or saline, and local field potentials recordings were performed using intracerebral electrodes positioned in distinct brain areas. Initially, the effects on synaptic transmission of the gap-junctional blockers used in this study were determined. Neither carbenoxolone (CBX) nor 18-alpha-glycyrrhetinic acid altered chemical synaptic transmission at the concentrations tested. These two compounds, when injected via cannulae into the reticular nucleus of the thalamus (NRT), decreased significantly the duration of seizures as compared with saline injections or injections of the CBX inactive derivative glycyrrhizic acid. CBX injections into the hippocampus resulted in diminished seizure activity as well. NRT injections of trimethylamine, which presumably causes intracellular alkalinization (thereby promoting gap-junctional opening), enhanced seizures and spindle activity. These observations suggest that, in this rodent model, thalamic and limbic areas are involved in the synchronous paroxysmal activity and that GJC contributes to the spike-and-wave discharges.