Intravenous Delta-9-Tetrahydrocannabinol to Prevent Postoperative Nausea and Vomiting: A Randomized Controlled Trial.

BACKGROUND: Evidence suggests that cannabinoids can prevent chemotherapy-induced nausea and vomiting. The use of tetrahydrocannabinol (THC) has also been suggested for the prevention of postoperative nausea and vomiting (PONV), but evidence is very limited and inconclusive. To evaluate the effectiveness of IV THC in the prevention of PONV, we performed this double-blind, randomized, placebo-controlled trial with patient stratification according to the risk of PONV. Our hypothesis was that THC would reduce the relative risk of PONV by 25% compared with placebo. METHODS: With IRB approval and written informed consent, 40 patients at high risk for PONV received either 0.125 mg/kg IV THC or placebo at the end of surgery before emergence from anesthesia. The primary outcome parameter was PONV during the first 24 hours after emergence. Secondary outcome parameters included early and late nausea, emetic episodes and PONV, and side effects such as sedation or psychotropic alterations. RESULTS: The relative risk reduction of overall PONV in the THC group was 12% (95% confidence interval, -37% to 43%), potentially less than the clinically significant 25% relative risk reduction demonstrated by other drugs used for PONV prophylaxis. Calculation of the effect of treatment group on overall PONV by logistic regression adjusted for anesthesia time gave an odds ratio of 0.97 (95% confidence interval, 0.21 to 4.43, P = 0.97). Psychotropic THC side effects were clinically relevant and mainly consisted of sedation and confusion that were not tampered by the effects of anesthesia. The study was discontinued after 40 patients because of the inefficacy of THC against PONV and the finding of clinically unacceptable side effects that would impede the use of THC in the studied setting. CONCLUSIONS: Because of an unacceptable side effect profile and uncertain antiemetic effects, IV THC administered at the end of surgery before emergence from anesthesia cannot be recommended for the prevention of PONV in high-risk patients.

Point-of-care prothrombin time testing in paediatric intensive care: an observational study of the ease of use of two devices.

BACKGROUND: Two major difficulties arise when taking blood samples in children: the challenge of venous access and the comparatively large amount of blood required. OBJECTIVE: To assess the value of point-of-care prothrombin time testing in paediatric intensive care patients. We evaluated two point-of-care devices, CoaguChek XS Plus and CoaLine, assessing ease of use in clinical practice and correlation with the standard prothrombin time measurement of the haematology laboratory. DESIGN: Single-centre observational study. SETTING: Between October 2007 and March 2008, patients in an interdisciplinary paediatric ICU of a tertiary centre were analysed. PATIENTS OR OTHER PARTICIPANTS: Thirty-eight patients, 22 female and 16 male (58 and 42%), aged between 0 and 13 years, participated in the study. The intention was to evaluate the ease of use of the devices in daily clinical practice, and no exclusion criteria were applied. MAIN OUTCOME MEASURES: The usefulness of the two point-of-care devices in the paediatric setting was evaluated. Measurements of point-of-care and standard laboratory prothrombin time were compared in terms of agreement and correlation. RESULTS: CoaguChek XS Plus had a failure rate of 2%, CoaLine 17% and the laboratory standard 4%. CoaguChek XS Plus received a better ease of use rating than CoaLine by the study personnel. Compared with the laboratory standard, there was considerable variability of the observed measurements with both devices. The measurements of CoaguChek XS Plus and the standard had a correlation coefficient r of being 0.79. CoaLine and the standard had a correlation coefficient r value of 0.72. CONCLUSION: CoaguChek XS Plus showed 'good' agreement, whereas CoaLine showed 'moderate' agreement compared with prothrombin time values using the standard method. The fast availability of results and the reduction of the required blood volume are advantages of point-of-care tests in the paediatric setting.

Performance of the pediatric-sized i-gel compared with the Ambu AuraOnce laryngeal mask in anesthetized and ventilated children.

BACKGROUND: This prospective, randomized, controlled trial compares the performance of the pediatric i-gel (Intersurgical Ltd., Wokingham, United Kingdom) with the Ambu AuraOnce laryngeal mask (Ambu A/S, Ballerup, Denmark) in anesthetized and ventilated children. METHODS: With ethics committee approval and written informed consent, the authors included 208 children, aged 0-17 yr, scheduled for elective day-surgery under general anesthesia. The primary outcome variable was oropharyngeal leak pressure. Other outcome variables were first-attempt and overall success, time to sufficient ventilation, and adverse events. RESULTS: Demographic data did not differ between groups. The leak pressure of the i-gel was significantly higher than the leak pressure of the Ambu (mean ± SD: 22 ± 5 cm H2O vs. 19 ± 3, P < 0.01). First-attempt success was 91% for the i-gel and 93% for the Ambu (P = 0.50). Overall success was 93% for the i-gel versus 98% for the Ambu (P = 0.10). Successfully inserted i-gels needed to be secured by taping in place to ensure the seal in 44% (0% with the Ambu, P < 0.01). Insertion was faster with the Ambu (24 ± 8 s vs. 27 ± 11, P = 0.02). There were no major side effects with either device. CONCLUSIONS: The leak pressure of the i-gel was statistically but not clinically significantly higher than the leak pressure of the Ambu. Time to insertion was longer with the i-gel. Both airway devices are suitable for positive pressure ventilation with high success rates in infants and children. Because the i-gel is prone to sliding out, it must be taped in place to avoid loss of the airway.

Trauma-induced coagulopathy in severely injured patients: knowledge lost in translation?

BACKGROUND: Many guidelines exist on how to treat patients with multiple injuries correctly in an accident and emergency setting. The aim of the present work was to find out how well patients are treated focusing on trauma induced coagulopathy (TIC), and what anaesthetists involved in trauma care think about their own experiences with TIC. METHODS: In a retrospective chart review of patients with an Injury Severity Score (ISS) > or = 16 between October 2007 and October 2008. A total of 172 patients with multiple injuries (134 men, 38 women) were treated in the resuscitation room and underwent complete coagulation screening (international normalised ratio (INR), activated partial thromboplastin time (aPTT), thrombin time (TT)). The presence of TIC was defined as INR>1.5 and aPTT>60 s or TT>15 s. Additionally, during the weekly anaesthesia and critical care grand round, a short questionnaire about TIC management was distributed to all anaesthetists involved in trauma care. RESULTS: Of the 172 patients with multiple injuries, 56 (32.6%) had TIC at admission to the resuscitation bay and 7 of these 56 (12.5%) received fresh-frozen plasma in the first hour of treatment. The mean of 55 anaesthetists thought that TIC could be corrected within about 30 min, although a chart review shows that it takes about 60 min to get complete laboratory based coagulation screening results. However, 70% of the doctors are not satisfied with the laboratory results they receive concerning TIC. CONCLUSIONS: There is an obvious discrepancy between the content of guidelines and the everyday practice. Future academic efforts in the area of trauma care should therefore focus more on the translational approach and the implementation of existing knowledge rather than on simply formulating guidelines.

Is perioperative point-of-care prothrombin time testing accurate compared to the standard laboratory test?

There is no accepted way of measuring prothrombin time without time loss for patients undergoing major surgery who are at risk of intraoperative dilution and consumption coagulopathy due to bleeding and volume replacement with crystalloids or colloids. Decisions to transfuse fresh frozen plasma and procoagulatory drugs have to rely on clinical judgment in these situations. Point-of-care devices are considerably faster than the standard laboratory methods. In this study we assessed the accuracy of a Point-of-care (PoC) device measuring prothrombin time compared to the standard laboratory method. Patients undergoing major surgery and intensive care unit patients were included. PoC prothrombin time was measured by CoaguChek XS Plus (Roche Diagnostics, Switzerland). PoC and reference tests were performed independently and interpreted under blinded conditions. Using a cut-off prothrombin time of 50%, we calculated diagnostic accuracy measures, plotted a receiver operating characteristic (ROC) curve and tested for equivalence between the two methods. PoC sensitivity and specificity were 95% (95% CI 77%, 100%) and 95% (95% CI 91%, 98%) respectively. The negative likelihood ratio was 0.05 (95% CI 0.01, 0.32). The positive likelihood ratio was 19.57 (95% CI 10.62, 36.06). The area under the ROC curve was 0.988. Equivalence between the two methods was confirmed. CoaguChek XS Plus is a rapid and highly accurate test compared with the reference test. These findings suggest that PoC testing will be useful for monitoring intraoperative prothrombin time when coagulopathy is suspected. It could lead to a more rational use of expensive and limited blood bank resources.

Crossover comparison of the laryngeal mask supreme and the i-gel in simulated difficult airway scenario in anesthetized patients.

BACKGROUND: The single-use supraglottic airway devices LMA-Supreme (LMA-S; Laryngeal Mask Company, Henley-on-Thames, United Kingdom) and i-gel (Intersurgical Ltd, Wokingham, Berkshire, United Kingdom) have a second tube for gastric tube insertion. Only the LMA-S has an inflatable cuff. They have the same clinical indications and might be useful for difficult airway management. This prospective, crossover, randomized controlled trial was performed in a simulated difficult airway scenario using an extrication collar limiting mouth opening and neck movement. METHODS: Sixty patients were included. Both devices were placed in random order in each patient. Primary outcome was overall success rate. Other measurements were time to successful ventilation, airway leak pressure, fiberoptic glottic view, and adverse events. RESULTS: Success rate for the LMA-S was 95% versus 93% for the i-gel (P = 1.000). LMA-S needed shorter insertion time (34 +/- 12 s vs. 42 +/- 23 s, P = 0.024). Tidal volumes and airway leak pressure were similar (LMA-S 26 +/- 8 cm H20; i-gel 27 +/- 9 cm H20; P = 0.441). Fiberoptic view through the i-gel showed less epiglottic downfolding. Overall agreement in insertion outcome was 54 (successes) and 1 (failure) or 55 (92%) of 60 patients. The difference in success rate was 1.7% (95% CI -11.3% to 7.6%). CONCLUSIONS: Both airway devices had similar insertion success and clinical performance in the simulated difficult airway situation. The authors found less epiglottic downfolding and better fiberoptic view but longer insertion time with the i-gel. Our study shows that both devices are feasible for emergency airway management in patients with reduced neck movement and limited mouth opening.

Low-threshold monopolar motor mapping for resection of lesions in motor eloquent areas in children and adolescents.

OBJECT: Resection of lesions close to the primary motor cortex (M1) and the corticospinal tract (CST) is generally regarded as high-risk surgery due to reported rates of postoperative severe deficits of up to 50%. The authors' objective was to determine the feasibility and safety of low-threshold motor mapping and its efficacy for increasing the extent of lesion resection in the proximity of M1 and the CST in children and adolescents. METHODS: The authors analyzed 8 consecutive pediatric patients in whom they performed 9 resections for lesions within or close (≤ 10 mm) to M1 and/or the CST. Monopolar high-frequency motor mapping with train-of-five stimuli (pulse duration 500 µsec, interstimulus interval 4.0 msec, frequency 250 Hz) was used. The motor threshold was defined as the minimal stimulation intensity that elicited motor evoked potentials (MEPs) from target muscles (amplitude > 30 µV). Resection was performed toward M1 and the CST at sites negative to 1- to 3-mA high-frequency train-of-five stimulation. RESULTS: The M1 was identified through high-frequency train-of-five via application of varying low intensities. The lowest motor thresholds after final resection ranged from 1 to 9 mA in 8 cases and up to 18 mA in 1 case, indicating proximity to motor neurons. Intraoperative electroencephalography documented an absence of seizures during all surgeries. Two transient neurological deficits were observed, but there were no permanent deficits. Postoperative imaging revealed complete resection in 8 patients and a very small remnant (< 0.175 cm3) in 1 patient. CONCLUSIONS: High-frequency train-of-five with a minimal threshold of 1-3 mA is a feasible and safe procedure for resections in the proximity of the CST. Thus, low-threshold motor mapping might help to expand the area for safe resection in pediatric patients with lesions located within the precentral gyrus and close to the CST, and may be regarded as a functional navigational tool. The additional use of continuous MEP monitoring serves as a safety feedback for the functional integrity of the CST, especially because the true excitability threshold in children is unknown.

SWIVIT--Swiss video-intubation trial evaluating video-laryngoscopes in a simulated difficult airway scenario: study protocol for a multicenter prospective randomized controlled trial in Switzerland.

BACKGROUND: Video-laryngoscopes are marketed for intubation in difficult airway management. They provide a better view of the larynx and may facilitate tracheal intubation, but there is no adequately powered study comparing different types of video-laryngoscopes in a difficult airway scenario or in a simulated difficult airway situation. METHODS/DESIGN: The objective of this trial is to evaluate and to compare the clinical performance of three video-laryngoscopes with a guiding channel for intubation (Airtraq™, A. P. Advance™, King Vision™) and three video-laryngoscopes without an integrated tracheal tube guidance (C-MAC™, GlideScope™, McGrath™) in a simulated difficult airway situation in surgical patients. The working hypothesis is that each video-laryngoscope provides at least a 90% first intubation success rate (lower limit of the 95% confidence interval >0.9). It is a prospective, patient-blinded, multicenter, randomized controlled trial in 720 patients who are scheduled for elective surgery under general anesthesia, requiring tracheal intubation at one of the three participating hospitals. A difficult airway will be created using an extrication collar and taping the patients' head on the operating table to substantially reduce mouth opening and to minimize neck movement. Tracheal intubation will be performed with the help of one of the six devices according to randomization. Insertion success, time necessary for intubation, Cormack-Lehane grade and percentage of glottic opening (POGO) score at laryngoscopy, optimization maneuvers required to aid tracheal intubation, adverse events and technical problems will be recorded. Primary outcome is intubation success at first attempt. DISCUSSION: We will simulate the difficult airway and evaluate different video-laryngoscopes in this highly realistic and clinically challenging scenario, independently from manufacturers of the devices. Because of the sufficiently powered multicenter design this study will deliver important and cutting-edge results that will help clinicians decide which device to use for intubation of the expected and unexpected difficult airway. TRIAL REGISTRATION: NCT01692535.

Accuracy of prehospital diagnosis and triage of a Swiss helicopter emergency medical service.

BACKGROUND: Helicopter emergency medical services (HEMSs) have become a standard element of modern prehospital emergency medicine. This study determines the percentage of injured HEMS patients whose injuries were correctly recognized by HEMS physicians. METHODS: A retrospective level III evidence prognostic study using data from the largest Swiss HEMS, REGA (Rettungsflugwacht/Guarde Aérienne), on adult patients with trauma transported to a Level I trauma center (January 2006-December 2007). National Advisory Committee on Aeronautics (NACA) scores and the Injury Severity Score (ISS) were assessed to identify severely injured patients. Injured body regions diagnosed by REGA physicians were compared with emergency department discharge diagnoses. RESULTS: Four hundred thirty-three patients were analyzed. Median age was 42.1 years (interquartile range, 25.5-57.9). Three hundred twenty-three (74.6%) were men. Patients were severely injured, with an in-hospital NACA score of 4 or higher in 88.7% of patients and median ISS of 13. REGA physicians correctly recognized injuries to the head in 92.9%, to the femur in 90.5%, and to the tibia/fibula in 83.8% of patients. Injuries to these body regions were overdiagnosed in less than 30%. Abdominal injuries were missed in 56.1%, pelvic injuries in 51.8%, spinal injuries in 40.1%, and chest injuries in 31.2% of patients. CONCLUSION: This study shows that patients are adequately triaged by REGA physicians reflected by a NACA score 4 or higher in 88.7% of patients and a median ISS of 13. However, recognition of injured body regions seems to be challenging in the prehospital setting. Prospective studies on specific training of HEMS physicians for recognition of these injuries (e.g., portable ultrasonography, telemedicine) might help in the future. LEVEL OF EVIDENCE: Prognostic study, level III.

Does point of care prothrombin time measurement reduce the transfusion of fresh frozen plasma in patients undergoing major surgery? The POC-OP randomized-controlled trial.

BACKGROUND: Bleeding is a frequent complication during surgery. The intraoperative administration of blood products, including packed red blood cells, platelets and fresh frozen plasma (FFP), is often live saving. Complications of blood transfusions contribute considerably to perioperative costs and blood product resources are limited. Consequently, strategies to optimize the decision to transfuse are needed. Bleeding during surgery is a dynamic process and may result in major blood loss and coagulopathy due to dilution and consumption. The indication for transfusion should be based on reliable coagulation studies. While hemoglobin levels and platelet counts are available within 15 minutes, standard coagulation studies require one hour. Therefore, the decision to administer FFP has to be made in the absence of any data. Point of care testing of prothrombin time ensures that one major parameter of coagulation is available in the operation theatre within minutes. It is fast, easy to perform, inexpensive and may enable physicians to rationally determine the need for FFP. METHODS/DESIGN: The objective of the POC-OP trial is to determine the effectiveness of point of care prothrombin time testing to reduce the administration of FFP. It is a patient and assessor blind, single center randomized controlled parallel group trial in 220 patients aged between 18 and 90 years undergoing major surgery (any type, except cardiac surgery and liver transplantation) with an estimated blood loss during surgery exceeding 20% of the calculated total blood volume or a requirement of FFP according to the judgment of the physicians in charge. Patients are randomized to usual care plus point of care prothrombin time testing or usual care alone without point of care testing. The primary outcome is the relative risk to receive any FFP perioperatively. The inclusion of 110 patients per group will yield more than 80% power to detect a clinically relevant relative risk of 0.60 to receive FFP of the experimental as compared with the control group. DISCUSSION: Point of care prothrombin time testing in the operation theatre may reduce the administration of FFP considerably, which in turn may decrease costs and complications usually associated with the administration of blood products. TRIAL REGISTRATION: NCT00656396.