Impact of Infant Positioning on Cardiopulmonary Resuscitation Performance During Simulated Pediatric Cardiac Arrest: A Randomized Crossover Study.

OBJECTIVES: The primary objective was to determine the impact of infant positioning on cardiopulmonary resuscitation performance during simulated pediatric cardiac arrest. DESIGN: A single-center, prospective, randomized, unblinded manikin study. SETTING: Medical university-affiliated simulation facility. SUBJECTS: Fifty-two first-line professional rescuers (n = 52). INTERVENTIONS: Performance of cardiopulmonary resuscitation was determined using an infant manikin model in three different positions (on a table [T], on the provider's forearm with the manikin's head close to the provider's elbow [P], and on the provider's forearm with the manikin's head close to the provider's palm [D]). For the measurement of important cardiopulmonary resuscitation performance variables, a commercially available infant simulator was modified. In a randomized sequence, healthcare professionals performed single-rescuer cardiopulmonary resuscitation for 3 minutes in each position. Performances of chest compression (primary outcome), ventilation, and hands-off time were analyzed using a multilevel regression model. MEASUREMENTS AND MAIN RESULTS: Mean (± SD) compression depth significantly differed between table and the other two manikin positions (31 ± 2 [T], 29 ± 3 [P], and 29 ± 3 mm [D]; overall p < 0.001; repeated measures design adjusted difference: T vs P, -2 mm [95% CI, -2 to -1 mm]; T vs D, -1 mm [95% CI, -2 to -1 mm]). Secondary outcome variables showed no significant differences. CONCLUSIONS: Compressions were significantly deeper in the table group compared to positions on the forearm during cardiopulmonary resuscitation, yet the differences were small and perhaps not clinically important.

Soluble Receptor for Advanced Glycation End Products Quantifies Lung Injury in Polytraumatized Patients.

BACKGROUND: Biomarkers caused by blunt chest trauma might leak into the vascular compartment and therefore reflect the severity of parenchymal lung injury (PLI). Five promising proteins were preselected after a literature scan. The objective of our study was to identify a biomarker that is released abundantly into the serum shortly after trauma and reliably quantifies the loss of functional lung tissue. METHODS: Polytraumatized patients (aged ≥18 years, Injury Severity Score [ISS] ≥16) were included in our prospective observational study if they were admitted directly to our level I trauma center during the first hour after trauma occurred. Immediately after stabilizing the patient's condition, blood samples were taken and a whole-body computed tomographic (CT) scan was obtained. Biomarker levels were measured directly after admission and on day 2. PLI volume was calculated using volumetric analysis. RESULTS: One hundred thirty patients met the inclusion criteria. Compared with a matched healthy control population, median levels of the soluble receptor for advanced glycation end products (sRAGE) was almost 3 times higher and decreased by 41% on day 2. Higher initial median sRAGE levels were detected in patients with PLI compared with patients without PLI and in individuals with severe PLI compared with those with mild PLI. Spearman correlation analysis and a univariate linear log regression model revealed a significant correlation/equation between initial sRAGE levels and relative PLI volume. Receiver operating characteristic (ROC) statistics identified the initial sRAGE level as an indicator of severe PLI. CONCLUSIONS: sRAGE levels measured shortly after trauma seem to be a promising diagnostic tool to assess the severity of PLI in polytraumatized patients.

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.

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).

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.

Degrees of reality: airway anatomy of high-fidelity human patient simulators and airway trainers.

BACKGROUND: Human patient simulators and airway training manikins are widely used to train airway management skills to medical professionals. Furthermore, these patient simulators are employed as standardized "patients" to evaluate airway devices. However, little is known about how realistic these patient simulators and airway-training manikins really are. This trial aimed to evaluate the upper airway anatomy of four high-fidelity patient simulators and two airway trainers in comparison with actual patients by means of radiographic measurements. The volume of the pharyngeal airspace was the primary outcome parameter. METHODS: Computed tomography scans of 20 adult trauma patients without head or neck injuries were compared with computed tomography scans of four high-fidelity patient simulators and two airway trainers. By using 14 predefined distances, two cross-sectional areas and three volume parameters of the upper airway, the manikins' similarity to a human patient was assessed. RESULTS: The pharyngeal airspace of all manikins differed significantly from the patients' pharyngeal airspace. The HPS Human Patient Simulator (METI®, Sarasota, FL) was the most realistic high-fidelity patient simulator (6/19 [32%] of all parameters were within the 95% CI of human airway measurements). CONCLUSION: The airway anatomy of four high-fidelity patient simulators and two airway trainers does not reflect the upper airway anatomy of actual patients. This finding may impact airway training and confound comparative airway device studies.

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

INTRODUCTION: 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.

A comparison of paediatric airway anatomy with the SimBaby high-fidelity patient simulator.

BACKGROUND: The SimBaby high-fidelity patient simulator is a widely used paediatric simulator for the training of standard and critical airway management scenarios. Furthermore this simulator is frequently used for the evaluation of different airway devices and techniques. However, the anatomic structures of the SimBaby have not been compared to actual patients' anatomy. METHODS: The CT radiographic measures of the upper airway anatomy of two SimBaby simulators were compared to MRI images of the upper airway of 20 children aged 1-11 months who underwent routine MRI scans under sedation for diagnostic purposes. Various distances of the tongue, soft palate and pharynx, cross sectional areas and volumes of anatomic structures of the upper airway including the retroglossal airspace were compared. RESULTS: The SimBaby's retroglossal airspace volume greatly differed from the measurements in patients (SimBaby 5.3±0.4 vs. 1.9±0.8 cm(3) in infants, p<0.01). Furthermore the distance from the alveolar process of the mandible to the posterior pharyngeal wall was larger in the SimBaby than in infants (5.8±0.1 vs. 4.5±0.5 cm, p<0.001) and dimensions of the epiglottis and pharynx were larger in the Simbaby. CONCLUSION: The anatomic features of the SimBaby do not adequately simulate the upper airway anatomy of infants. These results imply inadequate realism of this simulator for airway training and compromise the validity of comparative trials of different airway devices with the SimBaby as airway model.

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.

A common gene variant in methionine synthase reductase is not associated with peak homocysteine concentrations after nitrous oxide anesthesia.

OBJECTIVES: Oxidation of vitamin B12 by nitrous oxide leads to the inactivation of methionine synthase resulting in elevated plasma total homocysteine concentrations. Methionine synthase reductase is the only human enzyme that is able to reverse the oxidation of vitamin B12, which also occurs naturally by reactive oxygen species. A common polymorphism in methionine synthase reductase, MTRR 66A>G, is associated with reduced enzyme activity. Thus, we hypothesized that patients with this gene variant develop higher plasma total homocysteine concentrations after nitrous oxide anesthesia than wild-type patients. METHODS: In this follow-up investigation of a previous gene association study, we prospectively included 140 healthy individuals undergoing elective surgery under general anesthesia that included 66% nitrous oxide. Peak postoperative plasma total homocysteine was the main outcome variable and was measured within 2 h after the end of anesthesia. The MTRR 66A>G genotype was determined after completion of the study. The association between genotype and peak postoperative total homocysteine was modeled with a general linear model. RESULTS: No association between MTRR 66A>G and immediate postoperative plasma total homocysteine after nitrous oxide anesthesia was detected. All three groups, stratified by genotype (MTRR 66AA, AG, GG), shared similar baseline characteristics and increases in plasma total homocysteine. The average increase in plasma homocysteine was 2.4 mumol/l (+28%) in all three groups indicating the expected inactivation of methionine synthase by nitrous oxide through oxidation of vitamin B12, but no genetic effect. CONCLUSION: In conclusion, this study showed that the MTRR 66A>G gene variant is not associated with peak elevated postoperative plasma total homocysteine after nitrous oxide anesthesia. Whether the gene influences the rate of recovery of methionine synthase remains to be determined.

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] microm) than wild-type or heterozygous patients (9.3 [7.5-15.5] microm; n = 115). The change in homocysteine after nitrous oxide anesthesia was tripled in homozygous patients compared with wild-type (5.6 microm [+60%] vs. 1.8 microm [+22%]). Only homozygous patients reached average homocysteine levels considered abnormal (> 15 microm). 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.

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.

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.

Epidemiology and outcome of pediatric trauma treated by an emergency-physician-staffed advanced life-support unit.

BACKGROUND: The aim of this study was to describe the epidemiology and outcome of pediatric trauma in the setting of an emergency-physician-staffed mobile advanced life support (ALS) unit serving a predominantly urban area in Austria. METHODS: In this retrospective chart review, all pediatric trauma patients (0-14 years of age) who were treated by a physician-staffed ALS unit in Innsbruck within a 3-year period were analyzed. In addition, hospital charts were assessed to determine the clinical course and the outcome of these patients. RESULTS: 113 injured children were treated by the physician-staffed ALS unit (1.5% of all runs) during the study period; a frequency of three pediatric trauma patients per month. On average, injuries were of moderate severity (2.6 +/- 1.3 on the NACA severity scale). Thirteen children (11.5%) sustained severe to life-threatening injuries and two of whom underwent out-of-hospital resuscitation. The majority of the injuries were caused by vehicular accidents and sports/recreation-related trauma; head trauma was the most frequent injury. Violence-related trauma including weapon-inflicted injuries was uncommon. 40% of the children were hospitalized. The overall outcome was favorable: 78% of the hospitalized children had no impairment at the time of discharge. By comparing the prehospital trauma diagnosis with the final diagnosis, we found that the vast majority of emergency-physician trauma diagnoses were accurate. CONCLUSION: Because the frequency of pediatric trauma is so low, ALS units may not gain adequate experience in the management of (severe) pediatric trauma, thus rendering regular training of paramount importance.

Percutaneous saline-enhanced radiofrequency ablation of unresectable hepatic tumors: initial experience in 26 patients.

OBJECTIVE: The purpose of our study was to evaluate the safety and efficacy of percutaneous saline-enhanced radiofrequency ablation for unresectable primary or metastatic hepatic tumors. SUBJECTS AND METHODS: Twenty-six patients with 15 hepatocellular carcinomas and 33 hepatic metastases (maximum diameter < or = 8.6 cm) were treated; of these, seven tumors in five patients were treated twice. Thus, 44 radiofrequency treatments were performed. Saline-enhanced and impedance-controlled radiofrequency ablation (0.5-1.1 mL/min of saline, 15-mm conductive portion of the electrode tip, 25-60 W, 5-43 min) was performed using MR imaging guidance. Coagulation necrosis, volume indexes, morbidity, and complications were assessed. RESULTS: The volume of coagulation necrosis 1-7 days after radiofrequency ablation was 1.6-126.6 cm(3) (median, 18.9 cm(3)), corresponding to coagulation diameters of 1.5-6.2 cm (median, 3.2 cm). The coagulation volume was significantly larger if there were more than four radiofrequency applications (p = 0.006). Tumors of 3 cm or less in diameter were eight times as likely to be successfully completely ablated (p = 0.01) and volume indexes of lesions treated with the patient under general anesthesia were significantly larger than those treated with the patient under conscious sedation (p < 0.001). Major complications occurred in four patients (15%). Incomplete ablation in 19 (35%) of 54 radiofrequency lesions was due to cooling by a large vessel nearby (n = 2) or to low power applied in painful (n = 11) or critical (n = 6) locations. Residual tumor was observed in 14 (58%) of 24 tumors evaluated 6-8 months after radiofrequency ablation. CONCLUSION: Percutaneous saline-enhanced and impedance-controlled radiofrequency ablation can be effective in the treatment of unresectable hepatic tumors and minimizes potential carbonization. A greater number of radiofrequency applications, general anesthesia, and increasing experience provide significantly better results.