Randomized crossover trial comparing physical strain on advanced life support providers during transportation using real-time automated feedback.

BACKGROUND: Feedback devices provide verbal and visual real-time information on cardiopulmonary resuscitation (CPR) quality. Feedback devices can improve the quality of CPR during transportation. It remains unclear if feedback has an effect on the physical strain felt by providers during ongoing CPR. OBJECTIVES: The objective was to assess the influence of real-time automated feedback on physical strain of rescuers during ongoing chest compressions in different means of transportation. METHODS: The study was a randomized crossover trial comparing physical strain on advanced life support (ALS) providers during chest compressions using real-time automated feedback in different transport environments: 1) a moving ambulance and 2) a flying helicopter. The authors measured objective and subjective measures of physical strain and calculated the difference in the rate pressure product (RPP) after 8 minutes of external chest compressions. RESULTS: There was no difference in the RPP (mean intraindividual difference = 21; 95% confidence interval [CI] = -1,438 to 1,480; p = 0.98) between using the feedback device versus no feedback. There was no significant interaction of vehicle type on the effect of feedback on the RPP. Feedback resulted in a significant mean perceived exertion reduction of a Borg scale score by 0.89 points (95% CI = 0.42 to 1.35; p < 0.001). For systolic and diastolic blood pressure, for serum lactate concentrations, and for the modified Nine Hole Peg Test (NHPT; measurement of fine motor skills), we found no statistically significant differences. CONCLUSIONS: Feedback devices for CPR during transportation do not have an effect on objective components of physical strain, but decrease perceived exertion in experienced rescuers in an experimental setting.

Randomized placebo controlled trial of furosemide on subjective perception of dyspnoea in patients with pulmonary oedema because of hypertensive crisis.

BACKGROUND: To compare the administration of furosemide with placebo on the subjective perception of dyspnoea in patients with acute pulmonary oedema because of hypertensive crisis. Design Randomized, controlled and double-blinded clinical trial. SETTING: Municipal emergency medical service system and university-based emergency department. PARTICIPANTS: Fifty-nine patients with pulmonary oedema because of hypertensive crisis. INTERVENTIONS: Additional to administration of oxygen, morphine-hydrochloride and urapidil until the systolic blood pressure was below 160mmHg, the patients were randomized to receive furosemide 80mg IV bolus (furosemide group) or saline placebo (placebo group). MAIN OUTCOME MEASURES: The primary outcome was the subjective perception of dyspnoea as measured with a modified BORG scale at one hour after randomization. Secondary outcome parameters were the subjective perception of dyspnoea of patients as measured with a modified BORG scale and a visual analogue scale at 2, 3 and 6h after randomization of the patient; course of the systolic arterial pressure and peripheral oxygen saturation and lactate at admission and at 6h after admission. RESULTS: In 25 patients in the furosemide group and in 28 patients in the placebo group, a BORG score could be obtained. There was no statistically significant difference in the severity of dyspnoea at one hour after randomization (P=0·40). The median BORG score at 1h after randomization in the furosemide group was 3 (IQR 2 to 4) compared to 3 (IQR 2 to 7) in the placebo group (P=0·40). Those patients who were randomized to the placebo group needed higher doses of urapidil at 20min after randomization. There were no significant differences in the rate of adverse events, nonfatal cardiac arrests or death between the two groups. CONCLUSIONS: The subjective perception of dyspnoea in patients with hypertensive pulmonary oedema was not influenced by the application of a loop-diuretic. Therefore, additional furosemide therapy needs to be scrutinized in the therapy of these patients.

Surface cooling for rapid induction of mild hypothermia after cardiac arrest: design determines efficacy.

OBJECTIVES: Recently, a novel cooling pad was developed for rapid induction of mild hypothermia after cardiac arrest. The aim of this study was to evaluate the cooling efficacy of three different pad designs for in-hospital cooling. METHODS: Included in this prospective interventional study were patients with esophageal temperature (Tes) > 34 degrees C on admission. The cooling pad consists of multiple cooling units, filled with a combination of graphite and water, which is precooled to -18 degrees C (design A) or to -9 degrees C (designs B and C) before use. The designs of the cooling pad differed in number, shape, and thickness of the cooling units, with weights of 9.7 kg (design A), 5.3 kg (design B), and 6.2 kg (design C). All three designs were tested in sequential order and were changed according to the results found in the previous trial. Cooling was started after admission until Tes = 34 degrees C, when the cooling pad was removed. The target temperature of Tes = 32-34 degrees C was maintained for 24 hours. Data are presented as medians and interquartile ranges (IQRs = 25%-75%) or proportions. RESULTS: Cooling rates were 3.4 degrees C/hour (IQR = 2.5-3.7) with design A (n = 12), 2.8 degrees C/hour (IQR = 1.6-3.3) with design B (n = 7), and 2.9 degrees C/hour (IQR = 1.9-3.6) with design C (n = 10; p = 0.5). To reach 34 degrees C, the cooling pad had to be exchanged with a new one due to melting and therefore depleting cooling capacity in three patients with design A, in five patients with design B, and in no patient with design C (p = 0.004). CONCLUSIONS: With adequate design and storage temperature, the cooling pad proved to be efficient for rapid in-hospital cooling of patients resuscitated from cardiac arrest.

Quality of closed chest compression on a manikin in ambulance vehicles and flying helicopters with a real time automated feedback.

CONTEXT: Automated verbal and visual feedback improves quality of resuscitation in out-of-hospital cardiac arrest and was proven to increase short-term survival. Quality of resuscitation may be hampered in more difficult situations like emergency transportation. Currently there is no evidence if feedback devices can improve resuscitation quality during different modes of transportation. OBJECTIVE: To assess the effect of real time automated feedback on the quality of resuscitation in an emergency transportation setting. DESIGN: Randomised cross-over trial. SETTING: Medical University of Vienna, Vienna Municipal Ambulance Service and Helicopter Emergency Medical Service Unit (Christophorus Flugrettungsverein) in September 2007. PARTICIPANTS: European Resuscitation Council (ERC) certified health care professionals performing CPR in a flying helicopter and in a moving ambulance vehicle on a manikin with human-like chest properties. INTERVENTIONS: CPR sessions, with real time automated feedback as the intervention and standard CPR without feedback as control. MAIN OUTCOME MEASURES: Quality of chest compression during resuscitation. RESULTS: Feedback resulted in less deviation from ideal compression rate 100 min(-1) (9+/-9 min(-1), p<0.0001) with this effect becoming steadily larger over time. Applied work was less in the feedback group compared to controls (373+/-448 cm x compression; p<0.001). Feedback did not influence ideal compression depth significantly. There was some indication of a learning effect of the feedback device. CONCLUSIONS: Real time automated feedback improves certain aspects of CPR quality in flying helicopters and moving ambulance vehicles. The effect of feedback guidance was most pronounced for chest compression rate.

Factors associated with a change in functional outcome between one month and six months after cardiac arrest: a retrospective cohort study.

AIM OF THE STUDY: The appropriate time point of evaluation of functional outcome in cardiac arrest survivors remains a matter of debate. In this cohort study we posed the hypothesis that there are no significant changes in Cerebral Performance Categories (CPC) between one month and six months after out-of hospital cardiac arrest. If changes were present we aimed to identify reasons for these changes. METHODS: Based on a cardiac arrest registry, a potential change in CPC and mortality between one month and six months after cardiac arrest was analysed. Variables that were associated with these changes were identified. RESULTS: Thirty percent of 681 patients showed a significant change in functional outcome and mortality between one month and six months after out-of hospital cardiac arrest, 12% improved in CPC, 1% deteriorated, 17% died. The only factor that was associated with an improvement in CPC in the multivariate analysis was time to restoration of spontaneous circulation (ROSC) (RRR 1.04, 95% CI 1.01-1.06, per minute). We could not find any significant factors associated with a deterioration of CPC. Factors that were associated with mortality were age (RRR 1.03, 95% CI 1.01-1.06) and ventricular fibrillation as initial cardiac rhythm (RRR 0.34, 95% CI 0.16-0.71). CONCLUSIONS: There is a relevant change of functional outcome even one month after out-of hospital cardiac arrest. Especially when studies compare patient groups with unequal arrest times, and an unequal distribution of initial cardiac rhythms a follow-up period longer than one month should be considered for the final outcome evaluation after cardiac arrest.

The strong ion gap and outcome after cardiac arrest in patients treated with therapeutic hypothermia: a retrospective study.

OBJECTIVE: This study investigates whether the strong ion gap (SIG) is associated with long-term outcome after cardiac arrest in patients treated with therapeutic hypothermia. The hypothesis of the study was that an elevated SIG was associated with unfavourable outcome after cardiac arrest. DESIGN: Retrospective review of records from 1995 to 2007 of patients who received cardiopulmonary resuscitation. SETTING: Emergency department of a university hospital. PATIENTS: Patients who were successfully resuscitated after cardiac arrest (n = 288) and treated with mild therapeutic hypothermia. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Acid-base variables were calculated according to Stewart's approach, as modified by Figge and Fencl, and were determined immediately on admission and 12 h after the return of spontaneous circulation. Acid-base variables were determined at 37 degrees C and are reported without correction for patient temperature. Differences in SIG were compared between patients with favourable (survival 6 months with cerebral performance category 1 or 2) and unfavourable outcomes. SIG on admission and 12 h after return of spontaneous circulation was higher in patients with unfavourable outcome (n = 151; 52%). SIG 12 h after return of spontaneous circulation was identified as an independent predictor of outcome. A SIG > 8.9 mmol/L was associated with an increased cumulative hazard of death. CONCLUSIONS: An elevated SIG 12 h after return of spontaneous circulation may be associated with unfavourable outcome in patients after cardiac arrest treated with mild therapeutic hypothermia. The unmeasured anions hidden behind an elevated SIG may represent markers of tissue damage.

Physical strain on advanced life support providers in different out of hospital environments.

OBJECTIVES: To examine to what extent the type of emergency medical transportation influences the physical response of advanced life support providers. BACKGROUND: Providing external chest compression during resuscitation is physically exhausting. If the decision is made to bring the patient to a hospital undergoing resuscitation procedures, there are usually two options for transportation: ambulance vehicles or helicopters. There should be discussion on deciding which means of transportation should be preferred, because there is evidence that the quality of rescuers performance influences patient's outcome. METHODS: The study was a randomised crossover trial comparing physical strain on 11 European Resuscitation Council (ERC) approved healthcare professionals during external chest compression in different environments: (a) moving ambulance vehicle vs. (b) flying helicopter, and both compared to (c) staying at the scene (control). MAIN OUTCOME MEASURES: Difference in heart rate to systolic blood pressure ratio after 8 min of external chest compression. Secondary outcomes were BORG-rate of perceived exertion scale, blood pressure, serum lactate, and a Nine Hole Peg Test. RESULTS: Mean heart rate to systolic blood pressure ratio was 0.89+/-0.21 in the ambulance vehicle compared to 1.01+/-0.21 in the flying helicopter (p=0.04) There were no significant differences in the secondary outcome parameters. Perceived exertion increased by resuscitation time in all groups. CONCLUSION: External chest compression CPR is possible in a flying helicopter as it is in a moving ambulance vehicle. There is no clinical relevant difference in physical strain during ALS between a flying helicopter and a moving ambulance car. As would be expected, the exertion increases with duration of CPR.

Thrombolytic therapy vs primary percutaneous intervention after ventricular fibrillation cardiac arrest due to acute ST-segment elevation myocardial infarction and its effect on outcome.

The aim of this study was to evaluate the effect of thrombolytic therapy on neurologic outcome and mortality in patients after cardiac arrest due to acute ST-elevation myocardial infarction and to compare this with those in patients treated with primary percutaneous coronary intervention (PCI). We retrospectively examined patients after they had ventricular fibrillation cardiac arrests. To assess the effect of thrombolysis and PCI on outcome, we used odds ratios and their 95% confidence intervals and logistic regression modeling. Thrombolysis was applied in 101 patients (69%) and PCI in 46 patients (31%). More patients who received thrombolysis had favorable functional neurologic recovery (cerebral performance category 1 and 2) and survived to 6 months compared with patients with primary PCI (P = .38 and P = .13, respectively). In patients with cardiac arrest due to ST-elevation myocardial infarction, it may be acceptable to use thrombolysis as a reperfusion strategy. This applies especially in hospitals where immediate PCI is not available.

Feasibility and efficacy of a new non-invasive surface cooling device in post-resuscitation intensive care medicine.

AIM OF THE STUDY: There is sufficient evidence that therapeutic hypothermia after non-traumatic cardiac arrest improves neurological outcome and reduces mortality. Many different invasive and non-invasive cooling devices are currently available. Our purpose was to show the efficacy, safety and feasibility using a non-invasive cooling device to control patient temperature within a range of 33-37 degrees C. MATERIALS AND METHODS: A convenience sample of patients who have been resuscitated successfully from cardiac arrest and were intended for mild hypothermia therapy according to the guidelines and inclusion criteria were studied in a prospective observational case series at an emergency department of a tertiary care university hospital. The Medivance Arctic Sun System provides a new, non-invasive approach to reach a target temperature of 33 degrees C quickly, to maintain the target temperature for 24h, and then to actively re-warm at 0.4 degrees C/h to normothermia. Cooling was applied using the Arctic Sun in 27 patients. Data are presented as median and the interquartile range (25, 75%). RESULTS: Median age was 58 (49.5, 70) years. Time from cooling start to target temperature was 137 (96, 168)min, cooling rate was 1.2 degrees C/h (0.8, 1.5), stability of target temperature during hypothermia maintenance phase was satisfactory at 33.0 degrees C (32.9, 33.1), and duration of re-warming was 428 (394, 452)min. CONCLUSION: Using the Arctic Sun System in post-resuscitation care medicine for cooling cardiac arrest survivors is feasible and has proven to be highly effective in lowering patients' temperature rapidly without inducing skin irritations.

Quality of closed chest compression in ambulance vehicles, flying helicopters and at the scene.

CONTEXT: Transport of patients during resuscitation is a critical procedure. In both, ambulances and helicopters the quality of resuscitation is potentially hampered due to the movement of the vehicle and confined space. To date, however, no direct comparison of the quality of resuscitation at the scene, during a helicopter flight and in a moving ambulance has been made. OBJECTIVE: Direct comparison of the quality of resuscitation at the scene, during a helicopter flight and in a moving ambulance. DESIGN: The study was performed in July 2005 as a randomised cross-over trial comparing different environments for resuscitation. SETTING: Medical University of Vienna. PARTICIPANTS: Eleven European Resuscitation Council (ERC) approved health care professionals. INTERVENTIONS: Interventions during resuscitation: (a) in a moving ambulance, (b) in a flying helicopter, were compared to those staying at the (c) scene (control). Each participant performed resuscitation in all three environments. MAIN OUTCOME MEASURES: Quality of chest compression during resuscitation. RESULTS: Compared to resuscitation at the scene, efficiency of chest compressions during a helicopter flight was 86% and 95% in the moving ambulance 95%. There were no differences in secondary outcomes (time without chest compression, total number of incorrect hand position relative to total compressions, and total number of incorrect pressure release relative to total compressions). CONCLUSIONS: Resuscitation during transport is feasible and relatively efficient. There is some difference between the environments, but there is no relevant difference between helicopters and ambulances regarding the effectiveness of CPR.

[Surgical reduction of fat surplus leading to pulmonary embolism]. / Pulmonalembolie nach chirurgischer Fettreduktion.

Surgical reduction of fat surplus is usually performed on healthy individuals and is reported as a safe procedure as it is not associated with a lethal outcome. Due to the anticipation of peri- and postoperative bleeding as a result of the large wound area, which may have a negative influence on the cosmetic result, patients often receive no or only inadequate anticoagulation. We report three cases in which surgical reduction of fat surplus led to sudden collapse and cardiac arrest. In all of our patients, fatal pulmonary embolism was the cause of cardiac arrest. These patients received only inadequate or no anticoagulation. Early postoperative mobilization, elastic stockings and compressive wound-dressing did not prevent pulmonary embolism. In addition to early postoperative mobilization of the patient and even though there is a risk of perioperative bleeding complications, the use of anticoagulation is highly recommended in surgical procedures like abdominoplasty or dermolipectomy. If sudden dyspnea, chest pain, collapse or cardiac arrest occurs after surgical interventions like these, pulmonary embolism should be considered and further diagnostic steps should be initiated.