The effect of adding clonidine to local anesthetics for nerve or plexus blocks remains unclear. The authors searched for randomized placebo-controlled trials testing the impact of adding clonidine to local anesthetics for peripheral single-injection nerve or plexus blocks in adults undergoing any surgery (except eye) without general anesthesia. Twenty trials (1,054 patients, 573 received clonidine) published 1992-2006 tested plexus (14 brachial, 1 cervical) and nerve blocks (2 sciatic/femoral, 1 midhumeral, 1 ilioinguinal/iliohypogastric, 1 ankle). Clonidine doses ranged from 30 to 300 microg; most patients received 150 microg. Clonidine prolonged the duration of postoperative analgesia (weighted mean difference 122 min; 95% confidence interval [CI] 74-169), sensory block (weighted mean difference 74 min; 95% CI 37-111), and motor block (weighted mean difference 141 min; 95% CI 82-199). In a subgroup of patients receiving an axillary plexus block, these effects were independent of whether clonidine was added to an intermediate or a long-acting local anesthetic. Clonidine increased the risk of arterial hypotension (odds ratio 3.61; 95% CI 1.52-8.55; number-needed-to-harm 11), orthostatic hypotension or fainting (odds ratio 5.07; 95% CI 1.20-21.4; number-needed-to-harm 10), bradycardia (odds ratio 3.09; 95% CI 1.10-8.64; number-needed-to-harm 13), and sedation (odds ratio 2.28; 95% CI 1.15-4.51; number-needed-to-harm 5). There was a lack of evidence of dose-responsiveness for beneficial or harmful effects. Clonidine added to intermediate or long-acting local anesthetics for single-shot peripheral nerve or plexus blocks prolongs duration of analgesia and motor block by about 2 h. The increased risk of hypotension, fainting, and sedation may limit its usefulness. Dose-responsiveness remains unclear.

BackgroundSimulation has become integral to the training of both undergraduate medical students and medical professionals. Due to the increasing degree of realism and range of features, the latest mannequins are referred to as high-fidelity simulators. Whether increased realism leads to a general improvement in trainees’ outcomes is currently controversial and there are few data on the effects of these simulators on participants’ personal confidence and self-assessment.MethodsOne-hundred-and-thirty-five fourth-year medical students were randomly allocated to participate in either a high- or a low-fidelity simulated Advanced Life Support training session. Theoretical knowledge and self-assessment pre- and post-tests were completed. Students’ performance in simulated scenarios was recorded and rated by experts.ResultsParticipants in both groups showed a significant improvement in theoretical knowledge in the post-test as compared to the pre-test, without significant intergroup differences. Performance, as assessed by video analysis, was comparable between groups, but, unexpectedly, the low-fidelity group had significantly better results in several sub-items. Irrespective of the findings, participants of the high-fidelity group considered themselves to be advantaged, solely based on their group allocation, compared with those in the low-fidelity group, at both pre- and post-self-assessments. Self-rated confidence regarding their individual performance was also significantly overrated.ConclusionThe use of high-fidelity simulation led to equal or even worse performance and growth in knowledge as compared to low-fidelity simulation, while also inducing undesirable effects such as overconfidence. Hence, in this study, it was not beneficial compared to low-fidelity, but rather proved to be an adverse learning tool.

In adults having surgery under general anesthesia, concomitant epidural analgesia reduces postoperative mortality and improves a multitude of cardiovascular, respiratory, and gastrointestinal morbidity endpoints compared with patients receiving systemic analgesia. Because adverse effects and technical failures cannot be ruled out, individual risk-benefit analyses and professional care are recommended.

Postoperative pain is often stated to be a significant contributor to a sympathetic stress response after surgery. However, hardly any evidence has been published to support this assumption. Hence it was the aim of this trial to investigate the relationship between postoperative pain and hemodynamic, endocrine, and autonomic parameters. A total of 85 postoperative patients in the recovery room were repeatedly asked to rate their pain on a numeric rating scale (NRS). Concurrently, the parameters of heart rate variability (HRV) were analysed, and mean arterial pressure (MAP), heart rate (HR) and respiration rate (RR) were recorded. Pain was categorized into no, mild, moderate, and severe. Blood samples were taken for epinephrine (EPI) and norepinephrine (NE) plasma level assessment at the time of recovery room admission and discharge, and each time pain was found decreased in categorized severity. A total of 239 pain readings were obtained. None of the investigated parameters correlated with NRS scores. NE was higher at NRS 5 to 10 vs. NRS 0 to 4 (mean [SEM]: 1009 [73] pg/mL vs. 872 [65] pg/mL; P<0.01). This was also found for MAP, but not for EPI or the parameters of HRV, HR, and RR. In contrast to common belief, the severity of postoperative pain does not appear to be associated with the degree of sympathetic stress response after surgery, and other factors such as surgical trauma may be more important. Importantly, the absence of signs of sympathetic stimulation cannot be seen as a guarantee for the absence of significant pain.

Background Performance of sufficient cardiopulmonary resuscitation (CPR) by medical personnel is critical to improve outcomes during cardiac arrest. It has however been shown that even health care professionals possess a lack of knowledge and skills in CPR performance. The optimal method for teaching CPR remains unclear, and data that compares traditional CPR instructional methods with newer modalities of CPR instruction are needed. We therefore conducted a single blinded, randomised study involving medical students in order to evaluate the short- and long-term effects of a classical CPR education compared with a bilateral approach to CPR training, consisting of problem-based learning (PBL) plus high fidelity simulation. Methods One hundred twelve medical students were randomized during a curricular anaesthesiology course to a control ( n = 54) and an intervention ( n = 58) group. All participants were blinded to group assignment and partook in a 30-min-lecture on CPR basics. Subsequently, the control group participated in a 90-min tutor-guided CPR hands-on-training. The intervention group took part in a 45-min theoretical PBL module followed by 45 min of high fidelity simulated CPR training. The rate of participants recognizing clinical cardiac arrest followed by sufficiently performed CPR was the primary outcome parameter of this study. CPR performance was evaluated after the intervention. In addition, a follow-up evaluation was conducted after 6 months. Results 51.9% of the intervention group met the criteria of sufficiently performed CPR as compared to only 12.5% in the control group on the day of the intervention ( p = 0.007). Hands-off-time as a marker for CPR continuity was significantly less in the intervention group (24.0%) as compared to the control group (28.3%, p = 0.007, Hedges’ g = 1.55). At the six-month follow-up, hands-off-time was still significantly lower in the intervention group (23.7% vs. control group: 31.0%, p = 0.006, Hedges’ g = 1.88) but no significant difference in sufficiently performed CPR was detected (intervention group: 71.4% vs. control group: 54.5%, p = 0.55). Conclusion PBL combined with high fidelity simulation training leads to a measurable short-term increase in initiating sufficient CPR by medical students immediately after training as compared to classical education. At six month post instruction, these differences remained only partially. Electronic supplementary material The online version of this article (10.1186/s12909-019-1626-7) contains supplementary material, which is available to authorized users.

a b s t r a c tOpioids are widely used as additives to local anesthetics for intrathecal anesthesia. Benefit and risk remain unclear. We systematically searched databases and bibliographies to February 2011 for full reports of randomized comparisons of any opioid added to any intrathecal local anesthetic with the local anesthetic alone in adults undergoing surgery (except cesarean section) and receiving single-shot intrathecal anesthesia without general anesthesia. We included 65 trials (3338 patients, 1932 of whom received opioids) published between 1983 and 2010. Morphine (0.05-2 mg) and fentanyl (10-50 lg) added to bupivacaine were the most frequently tested. Duration of postoperative analgesia was prolonged with morphine (weighted mean difference 503 min; 95% confidence interval [CI] 315 to 641) and fentanyl (weighted mean difference 114 min; 95% CI 60 to 168). Morphine decreased the number of patients needing opioid analgesia after surgery and decreased pain intensity to the 12th postoperative hour. Morphine increased the risk of nausea (number needed to harm [NNH] 9.9), vomiting (NNH 10), urinary retention (NNH 6.5), and pruritus (NNH 4.4). Fentanyl increased the risk of pruritus (NNH 3.3). With morphine 0.05 to 0.5 mg, the NNH for respiratory depression varied between 38 and 59 depending on the definition of respiratory depression chosen. With fentanyl 10 to 40 lg, the risk of respiratory depression was not significantly increased. For none of these effects, beneficial or harmful, was there evidence of dose-responsiveness. Consequently, minimal effective doses of intrathecal morphine and fentanyl should be sought. For intrathecal buprenorphine, diamorphine, hydromorphone, meperidine, methadone, pentazocine, sufentanil, and tramadol, there were not enough data to allow for meaningful conclusions.Ó

Simulation-based teaching (SBT) is increasingly used in medical education. As an alternative to other teaching methods there is a lack of evidence concerning its efficacy. The aim of this study was to evaluate the potency of SBT in anesthesia in comparison to problem-based discussion (PBD) with students in a randomized controlled setting. Thirty-three fourth-year medical students attending a curricular anesthesiology course were randomly allocated to either a session of SBT or a session of PBD on an emergency induction method. Ten days later all students underwent examination in a simulator. The performance of each student was evaluated by weighted tasks, established according to a modified Delphi process. Confidence and a multiple-choice questionnaire were additionally performed pre- and post-intervention. A total of 32 students completed the study. Participants in the SBT group presented with significantly higher self-assessment scores after the intervention than students in the PBD group. However, students in the SBT group achieved only slightly and statistically insignificantly higher scores in the theoretical and simulator examination (p > 0.05) with only a moderate effect size of d = 0.52. The current study demonstrates that both PBD and SBT lead to comparable short-term outcomes in theoretical knowledge and clinical skills. However, undesirably, SBT students overrated their anticipated clinical abilities and knowledge improvement.

Even though thoracotomy is associated with significant postoperative complications, a growing understanding of the underlying pathophysiology and advances in multimodal pain therapy concepts in this specific group of patients are promising improved postoperative outcomes and potential reduction of the incidence of persistent pain.