IntroductionCognitive Load Theory (CLT) relates to the efficiency with which individuals manipulate the limited capacity of working memory load. Repeated training generally results in individual performance increase and cognitive load decrease, as measured by both behavioral and neuroimaging methods. One of the known biomarkers for cognitive load is frontal theta band, measured by an EEG. Simulation-based training is an effective tool for acquiring practical skills, specifically to train new surgeons in a controlled and hazard-free environment. Measuring the cognitive load of young surgeons undergoing such training can help to determine whether they are ready to take part in a real surgery. In this study, we measured the performance of medical students and interns in a surgery simulator, while their brain activity was monitored by a single-channel EEG.MethodsA total of 38 medical students and interns were divided into three groups and underwent three experiments examining their behavioral performances. The participants were performing a task while being monitored by the Simbionix LAP MENTOR™. Their brain activity was simultaneously measured using a single-channel EEG with novel signal processing (Aurora by Neurosteer®). Each experiment included three trials of a simulator task performed with laparoscopic hands. The time retention between the tasks was different in each experiment, in order to examine changes in performance and cognitive load biomarkers that occurred during the task or as a result of nighttime sleep consolidation.ResultsThe participants’ behavioral performance improved with trial repetition in all three experiments. In Experiments 1 and 2, delta band and the novel VC9 biomarker (previously shown to correlate with cognitive load) exhibited a significant decrease in activity with trial repetition. Additionally, delta, VC9, and, to some extent, theta activity decreased with better individual performance.DiscussionIn correspondence with previous research, EEG markers delta, VC9, and theta (partially) decreased with lower cognitive load and higher performance; the novel biomarker, VC9, showed higher sensitivity to lower cognitive load levels. Together, these measurements may be used for the neuroimaging assessment of cognitive load while performing simulator laparoscopic tasks. This can potentially be expanded to evaluate the efficacy of different medical simulations to provide more efficient training to medical staff and measure cognitive and mental loads in real laparoscopic surgeries.

Background During the Syrian civil war, patients were initially treated on-site in Syria and later transferred to medical centers in Israel. Relevant details concerning the exact nature of injury and medical/surgical care received in Syria were unavailable to clinicians in Israel. Many of these patients required abdominal re-exploration for obvious or suspected problems related to their injury. Our aim is to present our approach to abdominal trauma patients who survived initial on-site surgery and needed subsequent abdominal re-exploration abroad, in our medical center. Methods Clinical data from all medical records were retrospectively analyzed. Each patient underwent total body computerized tomography on arrival, revealing diverse multi-organ trauma. We divided the patient population who had abdominal trauma into 4 sub-groups according to the location in which abdominal surgical intervention was performed (abdominal surgery performed only in Syria, surgery in Syria and subsequent re-laparotomy in Israel, abdominal surgery only in Israel, and management of patients without abdominal surgical intervention). We focused on missed injuries and post-operative complications in the re-laparotomy sub-group. Results By July 2018, 1331 trauma patients had been admitted to our hospital, of whom 236 had suffered abdominal trauma. Life-saving abdominal intervention was performed in 138 patients in Syria before arrival to our medical center. A total of 79 patients underwent abdominal surgery in Israel, of whom 46 (33%) required re-laparotomy. The absence of any communication between the surgical teams across the border markedly affected our medical approach. Indications for re-exploration included severe peritoneal inflammation, neglected or overlooked abdominal foreign bodies, hemodynamic instability and intestinal fistula. Mortality occurred in 37/236 patients, with severe abdominal trauma as the main cause of fatality in 10 of them (4.2%), usually following urgent re-laparotomy. Conclusions Lack of information about the circumstances of injury in an environment of catastrophe in Syria at the time and the absence of professional communication between the surgical teams across the border markedly dictated our medical approach. Our concerns were that some patients looked deceptively stable while others had potentially hidden injuries. We had no information on who had had definitive versus damage control surgery in Syria. The fact that re-operation was not performed by the same team responsible for initial abdominal intervention also posed major diagnostic challenges and warranted increased clinical suspicion and a change in our standard medical approach.

Background Serum biochemical changes during laparoscopic surgery and positive pressure pneumoperitoneum (PP) may reflect mild oxidative stress due to the ischemia-reperfusion (I/R) mechanism. However, there is still a controversy regarding the exact mechanism of PP in creating oxidative stress and whether the induction of PP causes I/R effects at all. To elucidate this debated issue, we studied, for the first time, the changes of I/R parameters in the serum, in a pilot study, during laparoscopic cholecystectomy using a reliable, independent exogenous oxidative biomarker, together with common intrinsic biomarkers of oxidative stress. Patients and methods Our study included 20 patients scheduled for elective laparoscopic cholecystectomy. We evaluated the levels of the extrinsic and endogenous markers for oxidative stress during awareness, under anesthesia, the end of surgery (abdominal CO2 evacuation), and 2 h afterward. Results After an initial increase in oxidative stress following anesthesia, we did not notice any further significant rise in the levels of the synthetic exogenous and the endogenous biomarkers at the end of the surgery and 2 h later on. However, a positive correlation was noted between the levels of both the intrinsic and extrinsic markers. Conclusions In our study, the capability of the extrinsic biomarker to detect mild oxidative stress was not validated. Our study stresses the heterogeneous nature of the oxidative reactions and the diversity of the endogenous and exogenous biomarkers while detecting various biochemical patterns under mild oxidative stress, during the short period of laparoscopic surgery.