Oliver Spelten

Comparison of different video laryngoscopes for emergency intubation in a standardized airway manikin with immobilized cervical spine by experienced anaesthetists. A randomized, controlled crossover trial

BACKGROUND The aim of the present study was to evaluate whether different video laryngoscopes (VLs) facilitate endotracheal intubation (ETI) faster or more secure than conventional laryngoscopy in a manikin with immobilized cervical spine. METHODS After local ethics board approval, a standard airway manikin with cervical spine immobilization by means of a standard stiff collar was placed on a trauma stretcher. We compared times until glottic view, ETI, cuff block and first ventilation were achieved, and verified the endotracheal tube position, when using Macintosh laryngoscope, Glidescope Ranger, Storz C-MAC, Ambu Pentax AWS, Airtraq, and McGrath Series5 VLs in randomized order. Wilcoxon signed-rank test and McNemars test were used for statistical analysis; p<0.05 was considered as significant. RESULTS Twenty-three anaesthetists (mean age 32.1±4.9 years, mean experience in anaesthesia of 6.9±4.8 years) routinely involved in the management of multitrauma patients participated. The primary study end point, time to first effective ventilation, was achieved fastest when using Macintosh laryngoscope (21.0±7.6s) and was significantly slower with all other devices (Airtraq 33.2±23.9 s, p=0.002; Pentax AirwayScope 32.4±14.9 s, p=0.001; Storz C-MAC 34.1±23.9 s, p<0.001; McGrath Series5 101.7±108.3 s, p<0.001; Glidescope Ranger 46.3±59.1 s, p=0.001). Overall success rates were highest when using Macintosh, Airtraq and Storz C-MAC devices (100%), and were lower in Ambu Pentax AWS and Glidescope Ranger (87%, p=0.5) and in McGrath Series5 device (72.2%, p=0.063). CONCLUSION When used by experienced anaesthesiologists, video laryngoscopes did not facilitate endotracheal intubation in this model with an immobilized cervical spine in a faster or more secure way than conventional laryngoscopy. However, data was gathered in a standardized model and further studies in real trauma patients are desirable to verify our findings.

Success rates and endotracheal tube insertion times of experienced emergency physicians using five video laryngoscopes: a randomised trial in a simulated trapped car accident victim.

Context No randomised controlled trial has yet compared different video laryngoscopes in respect of the success rates and the time taken to achieve endotracheal intubation in trapped car accident victims. Objective The aim of the present study was to evaluate whether five video laryngoscopes facilitate tracheal intubation more quickly or more securely than conventional laryngoscopy. Design Prospective, controlled, randomised crossover trial. Setting An airway manikin was placed on the drivers seat of a compact car. Access was possible only through the opened drivers door. Participants Twenty-five experienced anaesthetists. Intervention Tracheal intubation in a simulated trapped patient using video laryngoscopes in a typical out-of-hospital setting. Main outcome measures Times to achievement of a view of the glottis, tracheal intubation, cuff inflation, first ventilation and tracheal tube position were compared using a standard Macintosh laryngoscope or Glidescope Ranger, Storz C-MAC, Ambu-Pentax AWS, Airtraq and McGrath Series 5 video laryngoscopes in a randomised order. Wilcoxon signed-rank test and McNemar test were used for statistical analysis. A P value of less than 0.05 was considered statistically significant. Results Twenty-five anaesthetists (35.1 ± 7.3 years; 16 male, nine female) with an intubation experience of 374 ± 96 intubations per year and an experience of 9.1 ± 7.3 years participated. Glottic view, tracheal intubation, cuff inflation and first ventilation were achieved most rapidly with the Macintosh laryngoscope, although the Airtraq and Pentax AWS video laryngoscopes were not significantly slower. Times were significantly longer when the Glidescope Ranger, McGrath Series 5 or Storz C-MAC video laryngoscopes were used (P < 0.05), failure to place the endotracheal tube correctly was significantly commoner with the McGrath Series 5 than with the Macintosh (P = 0.031). Conclusion When attempting to intubate a trapped car accident victim, video laryngoscopes provide a better view of the glottis, but some delay tracheal intubation significantly. The devices with a tube guide (Airtraq and Ambu Pentax AWS) enable tracheal intubation to be achieved significantly faster and with a lower failure rate than devices without a tube guide. No video laryngoscope outperformed direct laryngoscopy with a Macintosh laryngoscope in this simulation study. Trial registration Clinicaltrials.gov NCT01182740.

An assessment of resuscitation quality in the television drama Emergency Room: Guideline non-compliance and low-quality cardiopulmonary resuscitation lead to a favorable outcome?

OBJECTIVE Two earlier studies found that outcome after cardiopulmonary resuscitation (CPR) in the television medical drama Emergency Room (ER) is not realistic. No study has yet evaluated CPR quality in ER. DESIGN Retrospective analysis of CPR quality in episodes of ER. SETTING Three independent board-certified emergency physicians trained in CPR and the American Heart Association (AHA) guidelines reviewed ER episodes in two 5-year time-frames (2001-2005 and 2005-2009). Congruency with the corresponding 2000 and 2005 AHA guidelines was determined for each CPR scene. PATIENTS None. INTERVENTIONS None. MAIN OUTCOME MEASURES To evaluate whether CPR is in agreement with the specific algorithms of the AHA guidelines. Fishers exact test and Mann-Whitney-U-test were used to evaluate statistical significance (P<0.05). RESULTS A total of 136 on-screen cardiac arrests occurred in 174 episodes. Trauma was the leading cause of cardiac arrest (56.6%), which was witnessed in 80.1%. Return of spontaneous circulation occurred in 38.2%. Altogether, 19.1% of patients survived until ICU admission, and 5.1% were discharged alive. CONCLUSIONS Only one CPR scene was in agreement with the published AHA guidelines. However, low-quality CPR and non-compliance with the guidelines resulted in favorable outcomes.

In a difficult access scenario, supraglottic airway devices improve success and time to ventilation.

The success of tracheal intubation (TI) is unacceptably low in unconventional positions. Supraglottic airway devices (SAD) have become an important alternative. An airway manikin was placed in a car, simulating an entrapped motor vehicle accident victim. The rescuer only had access through the driver’s door. Participants were (n=25) anaesthesiologists with experience in prehospital emergency medicine. They attempted to secure the airway by TI or an SAD (Ambu AuraOnce, iGel, laryngeal tube) in a random sequence. Performance was compared using the Wilcoxon signed-rank test. P values less than 0.05 were considered statistically significant. Fastest effective ventilation was achieved with iGel (11.5±6.9 s, P<0.001), followed by a laryngeal mask (15.1±5.6 s, P<0.001) and a laryngeal tube (17.6±5.3 s, P<0.001); TI was the slowest (42.8±23.9 s, comparator). iGel (P<0.001) and laryngeal mask (P=0.01) also significantly outperformed the laryngeal tube. First ventilation was achieved significantly faster with SADs compared with TI. Success rates were also higher when using SADs.

Tracheal intubation in the ice-pick position with video laryngoscopes: A randomised controlled trial in a manikin

CONTEXT Tracheal intubation in nonstandardised positions is associated with a higher risk of tube misplacement and may have deleterious consequences for patients. Video laryngoscopes for tracheal intubation facilitate both glottic view and success rates. However, their use in the ice-pick position has not been evaluated. OBJECTIVE To evaluate the role of video laryngoscopes for tracheal intubation in the ice-pick position. DESIGN A randomised, controlled manikin trial. SETTING A standardised airway manikin was placed in the corner of a room. Tracheal intubation was only possible from the lower right side of the manikin. In randomised order, participants used a standard Macintosh laryngoscope and GlideScope Ranger, Storz C-MAC, Pentax AWS, Airtraq and McGrath Series5 video laryngoscopes. Statistical analysis was performed using the Wilcoxon signed-rank and McNemars tests; A P value of less than 0.05 was deemed statistically significant. PARTICIPANTS Twenty anaesthesiologists, all emergency medicine board-certified. MAIN OUTCOME MEASURES Time to first ventilation (primary); time to glottic view and confirmation of tube position (secondary). RESULTS Successful ventilation was achieved most rapidly with the Macintosh laryngoscope (36.1 ± 13.4 s; reference method), followed by the Airtraq (38.4 ± 36.3 s; P = n.s.), Pentax AWS (51.6 ± 43.3 s; P = n.s.) and Storz C-Mac (62.7 ± 49.7 s; P = n.s.). The use of the GlideScope Ranger (79.8 ± 61.9 s, P = 0.01) and McGrath series5 (79.8 ± 58.5 s, P = 0.023) resulted in significantly longer times. When comparing overall intubation success, the rate of successful tracheal intubation was higher with the Airtraq than with the McGrath Series5 (P = 0.031; all others n.s.). CONCLUSION The use of video laryngoscopes did not result in higher success rates or faster tracheal intubation in the ice-pick position when compared with conventional laryngoscopy in this manikin study. TRIAL REGISTRATION www.clinicaltrials.gov, NCT01210105.

Hyperoxia-Induced Protein Alterations in Renal Rat Tissue: A Quantitative Proteomic Approach to Identify Hyperoxia-Induced Effects in Cellular Signaling Pathways

Introduction. In renal tissue as well as in other organs, supranormal oxygen pressure may lead to deleterious consequences on a cellular level. Additionally, hyperoxia-induced effect in cells and related free radicals may potentially contribute to renal failure. The aim of this study was to analyze time-dependent alterations of rat kidney protein expression after short-term normobaric hyperoxia using proteomics and bioinformatic approaches. Material and Methods. N = 36 Wistar rats were randomized into six different groups: three groups with normobaric hyperoxia (exposure to 100% oxygen for 3 h) and three groups with normobaric normoxia (NN; room air). After hyperoxia exposure, kidneys were removed immediately, after 3 days and after 7 days. Kidney lysates were analyzed by two-dimensional gel electrophoresis followed by peptide mass fingerprinting using tandem mass spectrometry. Statistical analysis was performed with DeCyder 2D software (p < 0.01). Biological functions of differential regulated proteins were studied using functional network analysis (Ingenuity Pathways Analysis and PathwayStudio). Results. Expression of 14 proteins was significantly altered (p < 0.01): eight proteins (MEP1A_RAT, RSSA_RAT, F16P1_RAT, STML2_RAT, BPNT1_RAT, LGMN_RAT, ATPA_RAT, and VDAC1_RAT) were downregulated and six proteins (MTUS1_RAT, F16P1_RAT, ACTG_RAT, ACTB_RAT, 2ABA_RAT, and RAB1A_RAT) were upregulated. Bioinformatic analyses revealed an association of regulated proteins with inflammation. Conclusions. Significant alterations in renal protein expression could be demonstrated for up to 7 days even after short-term hyperoxia. The identified proteins indicate an association with inflammation signaling cascades. MEP1A and VDAC1 could be promising candidates to identify hyperoxic injury in kidney cells.

Dispatcher-assisted compression-only cardiopulmonary resuscitation provides best quality cardiopulmonary resuscitation by laypersons: A randomised controlled single-blinded manikin trial.

BACKGROUND High-quality cardiopulmonary resuscitation (CPR) by laypersons is a key determinant of both outcome and survival for out-of-hospital cardiac arrest. Dispatcher-assisted CPR (telephone-CPR, T-CPR) increases the frequency and correctness of bystander-CPR but results in prolonged time to first chest compressions. However, it remains unclear whether instructions for rescue ventilation and/or chest compressions should be recommended for dispatcher-assisted CPR. OBJECTIVE The aim of this study was to evaluate both principles of T-CPR with respect to CPR quality. DESIGN Randomised controlled single-blinded manikin trial. SETTING University Hospital of Cologne, Germany, 1 July 2012 to 30 September 2012. PARTICIPANTS Sixty laypersons between 18 and 65 years. Medically educated individuals, medical professionals and pregnant women were excluded. Participants were asked to resuscitate a manikin and were randomised into three groups: not dispatcher-assisted (uninstructed) CPR (group 1; U-CPR; n = 20), dispatcher-assisted compression-only CPR (group 2; DACO-CPR; n = 19) and full dispatcher-assisted CPR with rescue ventilation (group 3; DAF-CPR; n = 19). MAIN OUTCOME MEASURES Specific parameters of CPR quality [i.e. no-flow-time (NFT) as well as compression and ventilation parameters] were analysed. To compare different groups we used Students t test and P less than 0.05 was considered significant. RESULTS Initial NFT was lowest in the DACO-CPR group (mean 21.3 ± 14.4%), followed by dispatcher-assisted full CPR (mean 49.1 ± 8.5%) and by unassisted CPR (mean 55.0 ± 12.9%). Initial NFT covering the time of instruction was lower in DACO-CPR (12.1 ± 5.4%) as compared to dispatcher-assisted full CPR (20.7 ± 8.1%). Compression depth was similar in all three groups: 40.6 ± 13.0 mm (unassisted CPR), 41.0 ± 12.2 mm (DACO-CPR) and 38.8 ± 15.8 mm (dispatcher-assisted full CPR). Average compression frequency was highest in the DACO-CPR group (65.2 ± 22.4 min−1) compared with the unassisted CPR group (35.6 ± 24.2 min−1) and the dispatcher-assisted full CPR group (44.5 ± 10.8 min−1). Correct rescue ventilation was given in 3.1 ± 11.1% (unassisted CPR) and 1.6 ± 16.1% (dispatcher-assisted full CPR) of all ventilation attempts. CONCLUSION Best quality of CPR was achieved by DACO-CPR because of superior compression frequencies and reduced NFT. In contrast, the full dispatcher-assisted CPR with a longer initial instructing phase (initial NFT) did not result in enhanced CPR quality or an optimised compression depth.

Helicopter type and accident severity in helicopter emergency medical services missions

OBJECTIVE Whereas accident rates and fatal accident rates for Helicopter Emergency Medical Services (HEMS) were investigated sufficiently, resulting consequences for the occupants remain largely unknown. The present study aimed to classify HEMS accidents in Germany to prognosticate accident severity with regard to the helicopter model used. METHODS German HEMS accidents (1 Sept. 1970-31 Dec. 2009) were gathered as previously reported. Accidents were categorized in relation to the most severe injury, i.e., (1) no; (2) slight; (3) severe; and (4) fatal injuries. Only helicopter models with at least five accidents were analyzed to retrieve representative data. Prognostication was estimated by the relative percentage of each injury type compared to the total number of accidents. RESULTS The model BO105 was most often involved in accidents (38 of 99), followed by BK117 and UH-1D. OfN = 99 accidents analyzed, N = 63 were without any injuries (63.6%), N = 8 resulted in minor injuries of the occupants (8.1%), and N = 9 in major injuries (9.1%). Additionally, N = 19 fatal accidents (19.2%) were registered. EC135 and BK1 17 had the highest incidence of uninjured occupants (100% vs. 88.2%) and the lowest percentage of fatal injuries (0% vs. 5.9%; all P > 0.05). Most fatal accidents occurred with the models UH-1D, Bell 212, and Bell 412. DISCUSSION Use of the helicopter models EC135 and BK117 resulted in a high percentage of uninjured occupants. In contrast, the fatality rate was highest for the models Bell UH-I D, Bell 222, and Bell 412. Data from the present study allow for estimating accident risk in HEMS missions and prognosticating resulting fatalities, respectively.

APPLICATION OF THE FIA SCORE TO GERMAN RESCUE HELICOPTER ACCIDENTS TO PREDICT FATALITIES IN HELICOPTER EMERGENCY MEDICAL SYSTEMS (HEMS) CRASHES

BACKGROUND In the past several decades, multiple studies have examined factors influencing occupant survival in aviation crashes, but only a few have addressed this question in Helicopter Emergency Medical Systems (HEMS) accidents. The four-point FIA Score is a valid tool to measure fatality risk in aviation crashes. OBJECTIVE The aim of the present study was to analyze the performance of the FIA Score when applied to German HEMS accidents, and to determine the prognostic value for fatalities and for survival. METHODS The FIA Score uses three parameters (F=fire; I=Instrument meteorological conditions; A=Away from airport) to determine the fatality risk after crashes. Data for German HEMS accidents between October 1970 and December 2009 were gathered retrospectively from the Federal Agency for Flight Accident Investigation. Accidents were graded according to the FIA Score by two emergency physician-pilots, and crash fatality rates (CFR) were calculated. RESULTS A total of 99 HEMS accidents were analyzed that occurred from September 1970 to December 2009. In 19.2% of these, at least one occupant was fatally injured. There were 63 accidents (63.6%) that took place with no injuries; 8 occurred with minor injuries (8.1%); and 9 resulted in major injuries (9.1%). A total of 72 data sets were complete and were used for analysis. Depending on the FIA Score (FIA0, FIA1, FIA2, and FIA3), CFRs of 0.0%, 8.1%, 53.3%, and 100.0%, respectively, were calculated. CONCLUSIONS The FIA Score is a valuable tool in German HEMS accident analysis. It can predict fatalities and is easy to use. Thus, it may also be a valuable tool in EMS call centers to predict survival after a crash.

Novel Navigated Ultrasound Compared With Conventional Ultrasound for Vascular Access—a Prospective Study in a Gel Phantom Model

OBJECTIVES The authors hypothesized that, compared with conventional ultrasound (CUS), the use of a novel navigated ultrasound (NUS) technology would increase success rates and decrease performance times of vascular access procedures in a gel phantom model. DESIGN A prospective, randomized, crossover study. SETTING A university Hospital. PARTICIPANTS Participants were 44 anesthesiologists with varying clinical experience. INTERVENTIONS Anesthesiologists performed in-plane and out-of-plane vascular access procedures using both NUS and CUS for needle visualization in a gel phantom model. MEASUREMENTS AND MAIN RESULTS Procedure time was measured from needle insertion to verbalization of final needle positioning by the participants, and successful needle placement into the simulated vessel was verified by aspiration of simulated blood. By employing ultrasound navigation capabilities in addition to real-time ultrasound imaging during in-plane/long-axis vascular access procedures, median procedure time showed a nonsignificant decrease (7.5 seconds v 13.0 seconds; p = 0.028), and the observed increase in procedure success rate (90.9% v 100%; p = 0.125) did not reach statistical significance. For out-of-plane/short-axis vascular access procedures, a significant reduction in median procedure time (5.0 seconds v 11.5 seconds; p<0.001) and a significant increase in procedure success rate (75% v 100%; p<0.001) were achieved by using navigation technology combined with real-time ultrasound. CONCLUSIONS NUS technology improved the performance times and success rates of vascular access procedures conducted by anesthesiologists in a gel phantom model.