Patrick Schoettker

Evaluation of six videolaryngoscopes in 720 patients with a simulated difficult airway: a multicentre randomized controlled trial

BACKGROUND Videolaryngoscopes are aggressively marketed, but independent evaluation in difficult airways is scarce. This multicentre, prospective randomized controlled trial evaluates six videolaryngoscopes in patients with a simulated difficult airway. METHODS With ethics committee approval and written informed consent, 12 senior anaesthetists intubated the trachea of 720 patients. A cervical collar limited mouth opening and neck movement, making intubation difficult. We evaluated three unchannelled (C-MAC™ D-blade, GlideScope™, and McGrath™) and three channelled videolaryngoscopes (Airtraq™, A.P. Advance™ difficult airway blade, and KingVision™). The primary outcome was first-attempt intubation success rate. Secondary outcomes included overall success rate, laryngeal view, intubation times, and side-effects. The primary hypothesis for every videolaryngoscope was that the 95% confidence interval of first-attempt success rate is ≥90%. RESULTS Mouth opening was decreased from 46 (sd 7) to 23 (3) mm with the cervical collar. First-attempt success rates were 98% (McGrath™), 95% (C-MAC™ D-blade), 87% (KingVision™), 85% (GlideScope™ and Airtraq™), and 37% (A.P. Advance™, P<0.01). The 95% confidence interval of first-attempt success rate was >90% only for the McGrath™. Overall success, laryngeal view, and intubation times differed significantly between videolaryngoscopes (all P<0.01). Side-effects were minor. CONCLUSIONS This trial revealed differences in the performance of six videolaryngoscopes in 720 patients with restricted neck movement and limited mouth opening. In this setting, first-attempt success rates were 85-98%, except for the A.P. Advance™ difficult airway blade. Highest success and lowest tissue trauma rates were achieved by the McGrath™ and C-MAC™ D-blade, highlighting the importance of the videolaryngoscope blade design. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov: identifier NCT01692535.

Evaluation of the GlideScope® for tracheal intubation in patients with cervical spine immobilisation by a semi‐rigid collar

Application of cervical collars may reduce cervical spine movements but render tracheal intubation with a standard laryngoscope difficult if not impossible. We hypothesised that despite the presence of a Philadelphia Patriot® cervical collar and with the patient’s head taped to the trolley, tracheal intubation would be possible in 50 adult patients using the GlideScope® and its dedicated stylet. Laryngoscopy was attempted using a Macintosh laryngoscope with a size 4 blade, and the modified Cormack–Lehane grade was scored. Subsequently, laryngoscopy with the GlideScope was graded and followed by tracheal intubation. All patients’ tracheas were successfully intubated with the GlideScope. The median (IQR) intubation time was 50 s (43–61 s). The modified Cormack–Lehane grade was 3 or 4 at direct laryngoscopy. It was significantly reduced with the GlideScope (p < 0.0001), reaching grade 2a in most patients. Tracheal intubation in patients wearing a semi‐rigid collar and having their head taped to the trolley is possible with the help of the GlideScope.

Accuracy of Brain Multimodal Monitoring to Detect Cerebral Hypoperfusion After Traumatic Brain Injury

Objective:To examine the accuracy of brain multimodal monitoring—consisting of intracranial pressure, brain tissue PO2, and cerebral microdialysis—in detecting cerebral hypoperfusion in patients with severe traumatic brain injury. Design:Prospective single-center study. Patients:Patients with severe traumatic brain injury. Setting:Medico-surgical ICU, university hospital. Intervention:Intracranial pressure, brain tissue PO2, and cerebral microdialysis monitoring (right frontal lobe, apparently normal tissue) combined with cerebral blood flow measurements using perfusion CT. Measurements and Main Results:Cerebral blood flow was measured using perfusion CT in tissue area around intracranial monitoring (regional cerebral blood flow) and in bilateral supra-ventricular brain areas (global cerebral blood flow) and was matched to cerebral physiologic variables. The accuracy of intracranial monitoring to predict cerebral hypoperfusion (defined as an oligemic regional cerebral blood flow < 35 mL/100 g/min) was examined using area under the receiver-operating characteristic curves. Thirty perfusion CT scans (median, 27 hr [interquartile range, 20–45] after traumatic brain injury) were performed on 27 patients (age, 39 yr [24–54 yr]; Glasgow Coma Scale, 7 [6–8]; 24/27 [89%] with diffuse injury). Regional cerebral blood flow correlated significantly with global cerebral blood flow (Pearson r = 0.70, p < 0.01). Compared with normal regional cerebral blood flow (n = 16), low regional cerebral blood flow (n = 14) measurements had a higher proportion of samples with intracranial pressure more than 20 mm Hg (13% vs 30%), brain tissue PO2 less than 20 mm Hg (9% vs 20%), cerebral microdialysis glucose less than 1 mmol/L (22% vs 57%), and lactate/pyruvate ratio more than 40 (4% vs 14%; all p < 0.05). Compared with intracranial pressure monitoring alone (area under the receiver-operating characteristic curve, 0.74 [95% CI, 0.61–0.87]), monitoring intracranial pressure + brain tissue PO2 (area under the receiver-operating characteristic curve, 0.84 [0.74–0.93]) or intracranial pressure + brain tissue PO2+ cerebral microdialysis (area under the receiver-operating characteristic curve, 0.88 [0.79–0.96]) was significantly more accurate in predicting low regional cerebral blood flow (both p < 0.05). Conclusion:Brain multimodal monitoring—including intracranial pressure, brain tissue PO2, and cerebral microdialysis—is more accurate than intracranial pressure monitoring alone in detecting cerebral hypoperfusion at the bedside in patients with severe traumatic brain injury and predominantly diffuse injury.

Accuracy of prehospital triage of trauma patients by emergency physicians: a retrospective study in western Switzerland.

Objective Accurate identification of major trauma patients in the prehospital setting positively affects survival and resource utilization. Triage algorithms using predictive criteria of injury severity have been identified in paramedic-based prehospital systems. Our rescue system is based on prehospital paramedics and emergency physicians. The aim of this study was to evaluate the accuracy of the prehospital triage performed by physicians and to identify the predictive factors leading to errors of triage. Methods Retrospective study of trauma patients triaged by physicians. Prehospital triage was analyzed using criteria defining major trauma victims (MTVs, Injury Severity Score >15, admission to ICU, need for immediate surgery and death within 48 h). Adequate triage was defined as MTVs oriented to the trauma centre or non-MTV (NMTV) oriented to regional hospitals. Results One thousand six hundred and eighti-five patients (blunt trauma 96%) were included (558 MTV and 1127 NMTV). Triage was adequate in 1455 patients (86.4%). Overtriage occurred in 171 cases (10.1%) and undertriage in 59 cases (3.5%). Sensitivity and specificity was 90 and 85%, respectively, whereas positive predictive value and negative predictive value were 75 and 94%, respectively. Using logistic regression analysis, significant (P<0.05) predictors of undertriage were head or thorax injuries (odds ratio >2.5). Predictors of overtriage were paediatric age group, pedestrian or 2 wheel-vehicle road traffic accidents (odds ratio >2.0). Conclusion Physicians using clinical judgement provide effective prehospital triage of trauma patients. Only a few factors predicting errors in triage process were identified in this study.

Comparison of the single-use Ambu® aScope™ 2 vs the conventional fibrescope for tracheal intubation in patients with cervical spine immobilisation by a semirigid collar*

Fibreoptic intubation remains a key technique for the management of difficult intubation. We randomly compared the second generation single‐use Ambu® aScope™ 2 videoscope with a standard re‐usable flexible intubating fibrescope in 50 tracheal intubations in patients with a difficult airway simulated by a semirigid collar. All patients’ tracheas were intubated successfully with the aScope 2 or the re‐usable fibrescope. The median (IQR [range]) time to intubate was significantly longer with the aScope 2 70 (55–97 [41?–226]) s vs 50 (40–59 [27–175]) s, p = 0.0003) due to an increased time to see the carina. Quality of vision was significantly lower with the aScope 2 (excellent 24 (48%) vs 49 (98%), p = 0.0001; good 22 (44%) vs 1 (2%), p = 0.0001; poor 4 (8%) vs 0, p = 0.12) but with no difference in the subjective ease to intubate (easy score of 31 (62%) vs 38 (76%), p = 0.19; intermediate 12 (24%) vs 7 (14%), p = 0.31; difficult 7 (14%) vs 5 (5%), p = 0.76). The longer times to intubate and the poorer scores for quality of vision do not support the use of the single‐use aScope 2 videoscope as an alternative to the re‐usable fibrescope.

Is trauma in Switzerland any different? Epidemiology and patterns of injury in major trauma - a 5-year review from a Swiss trauma centre

UNLABELLED Switzerland, the country with the highest health expenditure per capita, is lacking data on trauma care and system planning. Recently, 12 trauma centres were designated to be reassessed through a future national trauma registry by 2015. Lausanne University Hospital launched the first Swiss trauma registry in 2008, which contains the largest database on trauma activity nationwide. METHODS Prospective analysis of data from consecutively admitted shock room patients from 1 January 2008 to 31 December 2012. Shock room admission is based on physiology and mechanism of injury, assessed by prehospital physicians. Management follows a surgeon-led multidisciplinary approach. Injuries are coded by Association for the Advancement of Automotive Medicine (AAAM) certified coders. RESULTS Over the 5 years, 1,599 trauma patients were admitted, predominantly males with a median age of 41.4 years and median injury severity score (ISS) of 13. Rate of ISS >15 was 42%. Principal mechanisms of injury were road traffic (40.4%) and falls (34.4%), with 91.5% blunt trauma. Principal patterns were brain (64.4%), chest (59.8%) and extremity/pelvic girdle (52.9%) injuries. Severe (abbreviated injury scale [AIS] score ≥ 3) orthopaedic injuries, defined as extremity and spine injuries together, accounted for 67.1%. Overall, 29.1% underwent immediate intervention, mainly by orthopaedics (27.3%), neurosurgeons (26.3 %) and visceral surgeons (13.9%); 43.8% underwent a surgical intervention within the first 24 hours and 59.1% during their hospitalisation. In-hospital mortality for patients with ISS >15 was 26.2%. CONCLUSION This is the first 5-year report on trauma in Switzerland. Trauma workload was similar to other European countries. Despite high levels of healthcare, mortality exceeds published rates by >50%. Regardless of the importance of a multidisciplinary approach, trauma remains a surgical disease and needs dedicated surgical resources.

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

BackgroundVideo-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/DesignThe 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.DiscussionWe 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 registrationNCT01692535

Knowledge of Glasgow coma scale by air-rescue physicians

ObjectiveTo assess the theoretical and practical knowledge of the Glasgow Coma Scale (GCS) by trained Air-rescue physicians in Switzerland.MethodsProspective anonymous observational study with a specially designed questionnaire. General knowledge of the GCS and its use in a clinical case were assessed.ResultsFrom 130 questionnaires send out, 103 were returned (response rate of 79.2%) and analyzed. Theoretical knowledge of the GCS was consistent for registrars, fellows, consultants and private practitioners active in physician-staffed helicopters. The clinical case was wrongly scored by 38 participants (36.9%). Wrong evaluation of the motor component occurred in 28 questionnaires (27.2%), and 19 errors were made for the verbal score (18.5%). Errors were made most frequently by registrars (47.5%, p = 0.09), followed by fellows (31.6%, p = 0.67) and private practitioners (18.4%, p = 1.00). Consultants made significantly less errors than the rest of the participating physicians (0%, p < 0.05). No statistically significant differences were shown between anesthetists, general practitioners, internal medicine trainees or others.ConclusionAlthough the theoretical knowledge of the GCS by out-of-hospital physicians is correct, significant errors were made in scoring a clinical case. Less experienced physicians had a higher rate of errors. Further emphasis on teaching the GCS is mandatory.

Helicopter Rescue Involving the Winching of a Physician

INTRODUCTION We sought to study the operational and medical aspects of helicopter rescue missions involving the use of a winch. SETTING A single helicopter-based medical service of a pre-alpine region of Switzerland. METHODS We prospectively studied consecutive primary rescue interventions involving winching of a physician, from October 1, 1998 to October 1, 2002. Demographic, medical and operational aspects as well as outcome at 48 hours were analyzed. RESULTS We included 133 patients. Most (74%) were male, with traumatic injuries (77%). The median scene time of the nine severely injured patients (Injury Severity Scale [ISS] > 15) was significantly longer compared with the other patients (54 vs 37 minutes; P < .05). The main medical procedures performed were orotracheal intubation (n = 5), fracture reductions (n = 5), major analgesia with sedation (n = 4), and intravenous fluid administration of more than 1,500 mL (n = 4). Fourteen (10%) patients suffering from minor injuries were triaged by the physician and not airlifted to the hospital. All 133 patients were alive at 48 hours. Sixty-nine (52%) were still hospitalized. No secondary interhospital transfer was required. CONCLUSION Our study provides a better knowledge of injury profile, medical aspects, and outcomes of patients rescued necessitating a winching procedure.

Surgical Treatment of Severe Traumatic Brain Injury in Switzerland: Results from a Multicenter Study

OBJECTIVE Since the introduction of modern surgical techniques and monitoring tools for the treatment of severe traumatic brain injury (TBI) in Switzerland, standardized nationwide operative procedures are still lacking. This study aimed to assess surgical management and monitoring strategies in patients admitted throughout Switzerland with severe TBI. METHODS Demographic, clinical, and radiologic data from a prospective national cohort study on severe brain-injured patients (Patient-relevant Endpoints after Brain Injury from Traumatic Accidents [PEBITA]) were collected during a 3-year period. This study evaluated patients admitted to 7 of the 11 trauma centers included in PEBITA. We retrospectively analyzed surgery-related computed tomography (CT) findings prior to and after treatment, intracranial pressure (ICP) monitoring, size and technical features of craniotomy, as well as surgical complications. ResULTS: This study included 353 of the 921 patients enrolled in PEBITA who underwent surgical treatment for severe TBI. At admission, acute subdural hematoma was the most frequent focal lesion diagnosed (n = 154 [44%]), followed by epidural hematoma (n = 96 [27%]) and intracerebral hematoma (n = 84 [24%]). A total of 198 patients (61%) presented with midline shift. Clinical deterioration in terms of Glasgow Coma Scale scores or intractable ICP values as an indication for surgical evacuation or decompression were documented in 20% and 6%, respectively. A total of 97 (27.5%) only received a catheter/probe for ICP monitoring. Surgical procedures to treat a focal lesion or decompress the cerebrum were performed in 256 patients (72.5%). Of the 290 surgical procedures (excluding ICP probe implantation), craniotomy (137 [47.2%]) or decompressive craniectomy (133 [45.9%]) were performed most frequently. The mean size of craniectomy in terms of maximal linear width on the CT axial slice was 8.4 ± 2.9 cm. Intraoperative ICP monitoring was reported in 61% of the interventions. Significant intraoperative brain swelling was documented in 50.6% of the procedures. Surgery-related complications occurred in 89 cases (32%). CONCLUSION This study highlights the lack of standardized and systematic documentation of technical aspects of surgical treatment of patients presenting with severe TBI in Switzerland. Technical strategies such as size of craniectomy and the use of perioperative ICP measurement were not documented in a standardized manner. A prospective systematic surgical documentation system might contribute to future formulation of recommendations for the surgical treatment of patients presenting with severe TBI in Switzerland.