Michael Hüpfl

Chest-compression-only versus standard cardiopulmonary resuscitation: a meta-analysis.

BACKGROUND In out-of-hospital cardiac arrest, dispatcher-assisted chest-compression-only bystander CPR might be superior to standard bystander CPR (chest compression plus rescue ventilation), but trial findings have not shown significantly improved outcomes. We aimed to establish the association of chest-compression-only CPR with survival in patients with out-of-hospital cardiac arrest. METHODS Medline and Embase were systematically reviewed for studies published between January, 1985, and August, 2010, in which chest-compression-only bystander CPR was compared with standard bystander CPR for adult patients with out-of-hospital cardiac arrest. In the primary meta-analysis, we included trials in which patients were randomly allocated to receive one of the two CPR techniques, according to dispatcher instructions; and in the secondary meta-analysis, we included observational cohort studies of chest-compression-only CPR. All studies had to supply survival data. The primary outcome was survival to hospital discharge. A fixed-effects model was used for both meta-analyses because of an absence of heterogeneity among the studies (I(2)=0%). FINDINGS In the primary meta-analysis, pooled data from three randomised trials showed that chest-compression-only CPR was associated with improved chance of survival compared with standard CPR (14% [211/1500] vs 12% [178/1531]; risk ratio 1·22, 95% CI 1·01-1·46). The absolute increase in survival was 2·4% (95% CI 0·1-4·9), and the number needed to treat was 41 (95% CI 20-1250). In the secondary meta-analysis of seven observational cohort studies, no difference was recorded between the two CPR techniques (8% [223/2731] vs 8% [863/11 152]; risk ratio 0·96, 95% CI 0·83-1·11). INTERPRETATION For adults with out-of-hospital cardiac arrest, instructions to bystanders from emergency medical services dispatch should focus on chest-compression-only CPR. FUNDING US National Institutes of Health and American Heart Association.

Influence of Methylenetetrahydrofolate Reductase Gene Polymorphisms on Homocysteine Concentrations after Nitrous Oxide Anesthesia

Background:Mutations in the methylenetetrahydrofolate reductase (MTHFR) gene (677C>T, 1298A>C) cause elevated plasma homocysteine concentrations and have been linked to fatal outcomes after nitrous oxide anesthesia. This study tested the hypothesis that patients with common MTHFR 677C>T or 1298A>C mutations develop higher plasma homocysteine concentrations after nitrous oxide anesthesia than wild-type patients. Methods:In this prospective, observational cohort study with blinded, mendelian randomization, the authors included 140 healthy patients undergoing elective surgery. All patients received 66% nitrous oxide for at least 2 h. The main outcome variable, plasma total homocysteine, and folate, vitamin B12, and holotranscobalamin II were measured before, during, and after surgery. After completion of the study, all patients were tested for their MTHFR 677C>T or 1298A>C genotype. Results:Patients with a homozygous MTHFR 677C>T or 1298A>C mutation (n = 25) developed higher plasma homocysteine concentrations (median [interquartile range], 14.9 [10.0–26.4] &mgr;m) than wild-type or heterozygous patients (9.3 [7.5–15.5] &mgr;m; n = 115). The change in homocysteine after nitrous oxide anesthesia was tripled in homozygous patients compared with wild-type (5.6 &mgr;m [+60%] vs. 1.8 &mgr;m [+22%]). Only homozygous patients reached average homocysteine levels considered abnormal (> 15 &mgr;m). Plasma 5-methyl-tetrahydrofolate concentrations increased uniformly by 20% after nitrous oxide anesthesia, indicating the inactivation of methionine synthase and subsequent folate trapping. Holotranscobalamin II concentrations remained unchanged, indicating no effect of nitrous oxide on vitamin B12 plasma concentrations. Conclusions:This study shows that patients with a homozygous MTHFR 677C>T or 1298A>C mutation are at a higher risk of developing abnormal plasma homocysteine concentrations after nitrous oxide anesthesia.

Over-the-head cardiopulmonary resuscitation improves efficacy in basic life support performed by professional medical personnel with a single rescuer: a simulation study.

Two-rescuer cardiopulmonary resuscitation (CPR) is considered the best method for professional basic life support (BLS). However, in many prehospital cardiac arrest situations, one rescuer has to begin CPR alone while the other performs additional tasks. In theory, over-the-head CPR is a suitable alternative in this situation, with the added benefit of allowing the single rescuer to use a self-inflating bag for ventilation. In this trial, we compared standard single-rescuer CPR with over-the-head CPR in manikins. We planned this study using a crossover study design where each participant administered both CPR techniques in a randomized order. Ventilation and chest compression data were collected with analysis software during a 2-min CPR test for each technique. Sixty-seven emergency medical technician students participated in this trial. Over-the-head CPR allowed for superior ventilation compared to standard CPR (number of correct ventilations: 330 of 760 versus 279 of 779; P = 0.002). The quality of delivered chest compressions did not differ between the two groups (correct chest compressions: 4293 of 6304 versus 4313 of 6395; P = 0.44). In conclusion, our study has shown that over-the-head CPR may be an effective alternative BLS technique when a single professional rescuer has to perform CPR, likely offering superior ventilation and comparable chest compression quality compared with standard BLS.

Prehospital pediatric emergencies in Austrian helicopter emergency medical service – a nationwide, population-based cohort study

ZusammenfassungFRAGESTELLUNG: Kindernotfälle stellen im Notarztdienst eine große Herausforderung dar. Bislang gibt es nur wenige epidemiologische Daten zu Kindernotfällen in der Flugrettung. Daher war das Ziel, die Einsatzcharakteristika von Kindernotfällen in verschiedenen Einsatzregionen zu analysieren, die in ganz Österreich von der Christophorus Flugrettung versorgt werden. METHODIK: Es wurde eine retrospektive Kohortenstudie durchgeführt und alle Kinder unter 15 Jahren inkludiert, die im Untersuchungszeitraum (Januar 2006–Juni 2007) von der Christophorus Flugrettung versorgt wurden. RESULTATE: Im Untersuchungszeitraum wurden von insgesamt 26.850 Einsätzen 2207 (8,2 %) Kinder primär versorgt. Insgesamt waren 1543 Kinder (69,9 %) nicht lebensbedrohlich erkrankt oder verletzt. Die Rate an schwerwiegenden Kindernotfällen war im städtischen Einsatzgebiet (45,2 %) höher als im ländlichen (38,2 %) oder alpinen Gelände (20,3 %). Die häufigste Notfallkategorie waren Unfälle; die Häufigkeit von Verletzungen lag im ländlichen Bereich bei 54,2 % (582/1074), im städtischen Einsatzgebiet bei 60,3 % (44/73) und im alpinen Gelände bei 91,4 % (969/1060). Die häufigsten Einzeldiagnosen waren Frakturen (34,9 %; 557/1595) und Schädel-Hirn-Traumata (26,3 %; 419/1595). 82 (3,7 %) Kinder wurden prähospital intubiert, 42 (1,9 %) wurden aufgrund eines Herz-Kreislauf-Stillstands reanimiert und 19 (0,9 %) erhielten einen intraossären Zugang. SCHLUSSFOLGERUNGEN: Die epidemiologischen Charakteristika von Kindernotfällen in der österreichischen Luftrettung unterscheiden sich im städtischen, ländlichen und alpinen Einsatzgebiet. Aufgrund der fehlenden Erfahrung mit Kindernotfällen sind konsequente Aus- und Weiterbildung der Flugrettungsteams in erweiterten Notfalltechniken und in der Traumaversorgung von Kindern entscheidend.SummaryINTRODUCTION: Arguably, the most challenging emergencies encountered by emergency medical service crews involve children. Because only scant data exist about the epidemiology of pediatric emergencies in helicopter emergency medical service (HEMS) on a population level, we sought to determine the epidemiological characteristics stratified by responding area in a large nationwide sample. METHODS: This was a retrospective cohort study including all pediatric patients (0–14 years of age) who were treated by HEMS in Austria from January 2006 to June 2007 (18 months). RESULTS: Pediatric emergencies accounted for 2207 (8.2%) of a total of 26.850 helicopter rescue missions. Of those, 69.9% (n = 1543) were not involved in life-threatening emergencies. The rate of critical pediatric emergencies was higher in urban than in rural or alpine environment (45.2%, 38.2% and 20.3%, respectively). The most common chief complaint was trauma; the frequency of injuries ranged from 54.2% (582/1074) in rural area and 60.3% (44/73) in urban area to 91.4% (969/1060) in alpine environment. Fracture and head trauma (34.9%; 557/1595 and 26.3%; 419/1595, respectively) were the most common injuries. Advanced life support measures like tracheal intubation, cardiopulmonary resuscitation and intraosseous access were rarely performed (3.7%; n = 82, 1.9%; n = 42 and 0.9%; n = 19, respectively). CONCLUSIONS: Pediatric emergencies in Austrian HEMS show different epidemiological characteristics in alpine, urban and rural operational environments. Because of challenges and infrequency of prehospital pediatric emergencies, HEMS crews need to maintain their skills in pediatric advanced life support and trauma care.

Pediatric trauma in the Austrian alps: the epidemiology of sport-related injuries in helicopter emergency medical service

BACKGROUND/PURPOSE We aimed to examine the epidemiological characteristics and injury patterns of pediatric trauma in helicopter emergency medical service (HEMS) caused by sports/outdoor activities in alpine environment. METHODS This retrospective cohort study analyzed 912 primary HEMS missions for pediatric trauma (0-14 years of age) in Austrian Alps between 1 January 2006 and 30 June 2007. Children were stratified by age into toddlers (3-5 years), children in early (6-9 years), and late school age (10-14 years). RESULTS The majority of pediatric sports-related trauma in alpine environment was caused by skiing (82.1%; n=749). Pediatric patients were predominately in late school age and boys (72.8%, n=664 and 61.0%, n=556, respectively) and a minority (16.0%, n=146) was severely injured. Overall, fracture (47.0%, n=429), contusion (17.9%, n=163), and traumatic brain injury (17.0%, n=155) were the most common prehospital diagnoses. The most frequent pattern of injury was related to the head/face and spine (36.3%, n=331). CONCLUSIONS The knowledge about epidemiological characteristics of HEMS use for injured children in alpine environment may be essential for training requirements of HEMS crews and operational considerations of HEMS providers. The incidence of head and spinal injuries requires support for initiatives to promote helmet wear and appropriate risk behavior amongst skiers and snowboarders.

Preparedness of anesthesiologists working in humanitarian disasters

OBJECTIVE Many skills needed to provide patients with safe, timely, and adequate anesthesia care during humanitarian crisis and disaster relief operations are not part of the daily routine before deployment. An exploratory study was conducted to identify preparedness, knowledge, and skills needed for deployment to complex emergencies. METHODS Anesthesiologists who had been deployed during humanitarian crisis and disaster relief operations completed an online questionnaire assessing their preparedness, skills, and knowledge needed during deployment. Qualitative data were sorted by frequencies and similarities and clustered accordingly. RESULTS Of 121 invitations sent out, 55 (46%) were completed and returned. Of these respondents, 24% did not feel sufficiently prepared for the deployment, and 69% did not undertake additional education for their missions. Insufficient preparedness involved equipment, drugs, regional anesthesia, and related management. CONCLUSIONS As the lack of preparation and relevant training can create precarious situations, anesthesiologists and deploying agencies should improve preparedness for anesthesia personnel. (Disaster Med Public Health Preparedness. 2013;0;1-5).

MR‐guided percutaneous ethanol ablation of hepatocellular carcinomas before liver transplantation

It was the objective of this study to evaluate MR‐guided, percutaneous ethanol injection of hepatocellular carcinoma in ten patients scheduled for liver transplantation. Using a 0.2 T open MR scanner (Magnetom Open, Siemens Medical Systems, Erlangen, Germany) and percutaneous instillation of ethanol, 12 liver tumors (median tumor volume, 6.3; range, 0.6–43.2 ccm) were treated. Coagulation necrosis, morbidity, and post‐transplant histology were assessed. No major complications were observed. A mean of 16.4±11.4 ml ethanol was injected for each tumor. The median volume of the ablation necrosis was 12.3 (range, 0.3–48.3) ccm. Three tumors were retreated and complete radiological necrosis before liver transplantation was found in eight of 12 tumors (67%). One patient developed multifocal disease and was excluded from transplantation; thus nine of ten patients underwent liver transplantation within 3.9±3.1 months. In the explants, satellite nodules (n = 2), new liver tumors (n = 2) and a complete necrosis were found in five of 12 treated tumors (42%). During follow‐up (median 41.3; range, 0.4–86.1 months), three patients died, but no tumor‐seeding or post‐transplantation recurrence occurred. MR‐guided ethanol injection is feasible, and may delay tumor progression. However, the local recurrence rate is high, and the spatial resolution of a low‐field MR scanner limits the detection of small tumors.

The Impact of Monitoring on the Initiation of Cardiopulmonary Resuscitation in Children: Friend or Foe?

BACKGROUND:The immediate initiation and high quality of basic life support (BLS) are pivotal to improving patient outcome after cardiac arrest. Although cardiorespiratory monitoring could shorten the time to recognize the onset of cardiac arrest, little is known about how monitoring and the misinterpretation of monitor readings could impair the initiation of BLS. In this study, we assessed the speed of initiation and quality of BLS in simulated monitored and nonmonitored pediatric cardiac arrest. METHODS:Sixty residents frequently involved in the care of critically ill children were randomly assigned to either the intervention (monitoring) group or the control (nonmonitoring) group. Participants of both groups performed BLS in 1 of 2 clinically identical, unwitnessed simulated cardiac arrest scenarios. Although in 1 scenario cardiorespiratory monitoring (i.e., electrocardiogram) was attached, the other scenario reflected a nonmonitored cardiac arrest. Time to first chest compression was chosen as the primary outcome variable. Adherence to resuscitation guidelines and subjective performance ratings were secondary outcome variables. RESULTS:Participants in the monitoring group initiated chest compressions significantly later than those in the nonmonitoring group (91 ± 36 vs 71±26 seconds, hazard ratio, 0.26; 95% confidence interval, 0.14–0.49, P < 0.001). Six members of the monitoring group did not start chest compression within 5 minutes. Furthermore, adherence to the guidelines was better in the nonmonitoring group. Participants who were previously involved in BLS training did not show better performance. CONCLUSIONS:The presence of cardiorespiratory monitoring significantly delayed or even prevented the initiation of chest compressions and impaired the quality of BLS in simulated pediatric cardiac arrest. Based on these data, specific training should be conducted for exposed personnel.