Hypothermia for neuroprotection in adults after cardiac arrest.

BACKGROUND: Good neurological outcome after cardiac arrest is difficult to achieve. Interventions during the resuscitation phase and treatment within the first hours after the event are critical for a favourable prognosis. Experimental evidence suggests that therapeutic hypothermia is beneficial, and several clinical studies on this topic have been published. This review was originally published in 2009; updated versions were published in 2012 and 2016. OBJECTIVES: To evaluate the benefits and harms of therapeutic hypothermia after cardiac arrest in adults compared to standard treatment. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 30 September 2022. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and quasi-RCTs in adults comparing therapeutic hypothermia after cardiac arrest with standard treatment (control). We included studies with adults cooled by any method, applied within six hours of cardiac arrest, to target body temperatures of 32 °C to 34 °C. Good neurological outcome was defined as no or only minor brain damage allowing people to live an independent life. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcome was 1. neurological recovery. Our secondary outcomes were 2. survival to hospital discharge, 3. quality of life, 4. cost-effectiveness and 5. ADVERSE EVENTS: We used GRADE to assess certainty. MAIN RESULTS: We found 12 studies with 3956 participants reporting the effects of therapeutic hypothermia on neurological outcome or survival. There were some concerns about the quality of all the studies, and two studies had high risk of bias overall. When we compared conventional cooling methods versus any type of standard treatment (including a body temperature of 36 °C), we found that participants in the therapeutic hypothermia group were more likely to reach a favourable neurological outcome (risk ratio (RR) 1.41, 95% confidence interval (CI) 1.12 to 1.76; 11 studies, 3914 participants). The certainty of the evidence was low. When we compared therapeutic hypothermia with fever prevention or no cooling, we found that participants in the therapeutic hypothermia group were more likely to reach a favourable neurological outcome (RR 1.60, 95% CI 1.15 to 2.23; 8 studies, 2870 participants). The certainty of the evidence was low. When we compared therapeutic hypothermia methods with temperature management at 36 °C, there was no evidence of a difference between groups (RR 1.78, 95% CI 0.70 to 4.53; 3 studies; 1044 participants). The certainty of the evidence was low. Across all studies, the incidence of pneumonia, hypokalaemia and severe arrhythmia was increased amongst participants receiving therapeutic hypothermia (pneumonia: RR 1.09, 95% CI 1.00 to 1.18; 4 trials, 3634 participants; hypokalaemia: RR 1.38, 95% CI 1.03 to 1.84; 2 trials, 975 participants; severe arrhythmia: RR 1.40, 95% CI 1.19 to 1.64; 3 trials, 2163 participants). The certainty of the evidence was low (pneumonia, severe arrhythmia) to very low (hypokalaemia). There were no differences in other reported adverse events between groups. AUTHORS' CONCLUSIONS: Current evidence suggests that conventional cooling methods to induce therapeutic hypothermia may improve neurological outcomes after cardiac arrest. We obtained available evidence from studies in which the target temperature was 32 °C to 34 °C.

Impact of more conservative European Society of Cardiology guidelines on the management of patients with acute chest pain.

OBJECTIVE: Early diagnosis or rule-out of acute coronary syndrome (ACS) is a key competence of emergency medicine. Changes in the NSTE-ACS guidelines of the European Society of Cardiology (ESC) in 2015 and 2020 both warranted a henceforth more conservative approach regarding high-sensitivity troponin t (hsTnt) testing. We aimed to assess the impact of more conservative guidelines on the frequency of early rule-out and prolonged observation with repeated hsTnt testing at a high-volume tertiary care emergency department. PATIENTS AND METHODS: We conducted a pre- and post-changeover analysis 3 months before and 3 months after transition from less (hsTnt cut-off 30 ng/L, 3-hour rule-out) to more conservative (hsTnt cut-off 14 ng/L, 1-hour rule-out) guidelines in 2015, comparing proportions of patients requiring repeated testing. RESULTS: We included 5442 cases of symptoms suspicious of acute cardiac origin (3451 before, 1991 after, 2370 (44%) female, age 55 (SD 19) years). The proportion of patients fulfilling early-rule out criteria decreased from 68% (2348 patients) before to 60% (1195 patients) with the 2015 guidelines (P < .01). Those requiring repeated testing significantly (P < .01) increased from 22% (743 patients) to 25% (494 patients). Positive results in repeated testing significantly (P = .02) decreased from 43% (320 patients) to 37% (181 patients). Invasive diagnostics were performed in 91 patients (2.6%) before and in 75 patients (3.8%) after (P = .02) the guideline revision. CONCLUSION: The implementation of the more conservative 2015 ESC guidelines led to a minor rise in prolonged observations because of an increase in negative repeated testing and to an increase in invasive procedures.

Different Mortality Time Points in Critical Care Trials: Current Practice and Influence on Effect Estimates in Meta-Analyses.

OBJECTIVE: Mortality is frequently used as an outcome in critical care trials, being a patient-orientated variable and robust against information/selection bias. Mortality frequency, however, should be measured at a defined time point of follow-up. Practice of meta-analysis shows that follow-up times of trials in critical care medicine differ substantially. This may have substantial implications on potential pooling of effect estimates. We aimed to describe the current practice of mortality follow-up time definitions in a representative sample of published critical care randomized controlled trials and to analyze the influence of different follow-up times on subsequently pooled effect estimates. DATA SOURCES: Cochrane CENTRAL, EMBASE, MEDLINE, PASCAL Biomed, and PsycINFO. STUDY SELECTION: Databases were searched for critical care randomized controlled trials published after 2000. A random sample of 50% was drawn for further review. DATA EXTRACTION: Study characteristics were extracted, as well as the number and time points of mortality ascertainment. Additional data were extracted from Kaplan-Meier plots, as available. DATA SYNTHESIS: Meta-regression and multilevel mixed-effects linear regression were used to analyze the influence of follow-up time (independent variable) on deviation of pooled risk ratios from study baseline (dependent variable). From 9,246 retrieved references, we included 106 studies representing 63,713 participants. Among these, 45 studies (43%) reported more than one time point, with 24 different time points at all, only three (28, 30, and 90 d) being reported in more than 10% of studies. Limiting meta-analyses to only one predefined time point would reduce the number of eligible studies by at least 60%. No influence of time points on meta-analytic summary effect estimates was found. CONCLUSIONS: In a large sample of critical care randomized controlled trials, numerous different mortality time points are reported. Mortality time points did not influence pooled point estimates of the effects. Consequently, it seems possible to pool effect estimates, which in turn will increase the precision of these effect estimates.

Hypothermia for neuroprotection in adults after cardiopulmonary resuscitation.

BACKGROUND: Good neurological outcome after cardiac arrest is difficult to achieve. Interventions during the resuscitation phase and treatment within the first hours after the event are critical. Experimental evidence suggests that therapeutic hypothermia is beneficial, and several clinical studies on this topic have been published. This review was originally published in 2009; updated versions were published in 2012 and 2016. OBJECTIVES: We aimed to perform a systematic review and meta-analysis to assess the influence of therapeutic hypothermia after cardiac arrest on neurological outcome, survival and adverse events. SEARCH METHODS: We searched the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 10); MEDLINE (1971 to May 2015); EMBASE (1987 to May 2015); the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1988 to May 2015); and BIOSIS (1989 to May 2015). We contacted experts in the field to ask for information on ongoing, unpublished or published trials on this topic.The original search was performed in January 2007. SELECTION CRITERIA: We included all randomized controlled trials (RCTs) conducted to assess the effectiveness of therapeutic hypothermia in participants after cardiac arrest, without language restrictions. We restricted studies to adult populations cooled by any cooling method, applied within six hours of cardiac arrest. DATA COLLECTION AND ANALYSIS: We entered validity measures, interventions, outcomes and additional baseline variables into a database. Meta-analysis was performed only for a subset of comparable studies with negligible heterogeneity. We assessed the quality of the evidence by using standard methodological procedures as expected by Cochrane and incorporated the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach. MAIN RESULTS: We found six RCTs (1412 participants overall) conducted to evaluate the effects of therapeutic hypothermia - five on neurological outcome and survival, one on only neurological outcome. The quality of the included studies was generally moderate, and risk of bias was low in three out of six studies. When we compared conventional cooling methods versus no cooling (four trials; 437 participants), we found that participants in the conventional cooling group were more likely to reach a favourable neurological outcome (risk ratio (RR) 1.94, 95% confidence interval (CI) 1.18 to 3.21). The quality of the evidence was moderate.Across all studies that used conventional cooling methods rather than no cooling (three studies; 383 participants), we found a 30% survival benefit (RR 1.32, 95% CI 1.10 to 1.65). The quality of the evidence was moderate.Across all studies, the incidence of pneumonia (RR 1.15, 95% CI 1.02 to 1.30; two trials; 1205 participants) and hypokalaemia (RR 1.38, 95% CI 1.03 to 1.84; two trials; 975 participants) was slightly increased among participants receiving therapeutic hypothermia, and we observed no significant differences in reported adverse events between hypothermia and control groups. Overall the quality of the evidence was moderate (pneumonia) to low (hypokalaemia). AUTHORS' CONCLUSIONS: Evidence of moderate quality suggests that conventional cooling methods provided to induce mild therapeutic hypothermia improve neurological outcome after cardiac arrest, specifically with better outcomes than occur with no temperature management. We obtained available evidence from studies in which the target temperature was 34°C or lower. This is consistent with current best medical practice as recommended by international resuscitation guidelines for hypothermia/targeted temperature management among survivors of cardiac arrest. We found insufficient evidence to show the effects of therapeutic hypothermia on participants with in-hospital cardiac arrest, asystole or non-cardiac causes of arrest.

Pre-hospital versus in-hospital initiation of cooling for survival and neuroprotection after out-of-hospital cardiac arrest.

BACKGROUND: Targeted temperature management (also known under 'therapeutic hypothermia', 'induced hypothermia'", or 'cooling') has been shown to be beneficial for neurological outcome in patients who have had successful resuscitation from sudden cardiac arrest, but it remains unclear when this intervention should be initiated. OBJECTIVES: To assess the effects of pre-hospital initiation of cooling on survival and neurological outcome in comparison to in-hospital initiation of cooling for adults with pre-hospital cardiac arrest. SEARCH METHODS: We searched CENTRAL, MEDLINE, EMBASE, CINAHL, BIOSIS, and three trials registers from inception to 5 March 2015, and carried out reference checking, citation searching, and contact with study authors to identify additional studies. SELECTION CRITERIA: We searched for randomized controlled trials (RCTs) in adults with out-of-hospital cardiac arrest comparing cooling in the pre-hospital setting to in-hospital cooling. Our primary outcomes were survival and neurological outcome; our secondary outcomes were adverse events, quality of life, and length of stay in the intensive care unit (ICU) and in the hospital. DATA COLLECTION AND ANALYSIS: We used Cochrane's standard methodological procedures. MAIN RESULTS: We included seven RCTs (2369 participants randomized) on the induction of pre-hospital cooling in comparison to in-hospital cooling. There was considerable methodological heterogeneity and risk of bias mainly due to deficits in the administration of cooling, therefore we refrained from pooling the results for survival and neurological outcome and we presented the results for each study separately. Adverse events were rare: based on four studies with 1713 adults pre-hospital induction of cooling may increase the risk of cardiac re-arrests. Risk of bias within the seven individual studies was generally moderate. Overall the quality of the evidence was very low. This was mainly driven by inconsistency and low precision. AUTHORS' CONCLUSIONS: Currently, there is no convincing evidence to clearly delineate beneficial or harmful effects of pre-hospital induction of cooling in comparison to in-hospital induction of cooling. This conclusion is based on very low quality evidence.

Vasopressors for hypotensive shock.

BACKGROUND: Initial goal-directed resuscitation for hypotensive shock usually includes administration of intravenous fluids, followed by initiation of vasopressors. Despite obvious immediate effects of vasopressors on haemodynamics, their effect on patient-relevant outcomes remains controversial. This review was published originally in 2004 and was updated in 2011 and again in 2016. OBJECTIVES: Our objective was to compare the effect of one vasopressor regimen (vasopressor alone, or in combination) versus another vasopressor regimen on mortality in critically ill participants with shock. We further aimed to investigate effects on other patient-relevant outcomes and to assess the influence of bias on the robustness of our effect estimates. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015 Issue 6), MEDLINE, EMBASE, PASCAL BioMed, CINAHL, BIOSIS and PsycINFO (from inception to June 2015). We performed the original search in November 2003. We also asked experts in the field and searched meta-registries to identify ongoing trials. SELECTION CRITERIA: Randomized controlled trials (RCTs) comparing various vasopressor regimens for hypotensive shock. DATA COLLECTION AND ANALYSIS: Two review authors abstracted data independently. They discussed disagreements between them and resolved differences by consulting with a third review author. We used a random-effects model to combine quantitative data. MAIN RESULTS: We identified 28 RCTs (3497 participants) with 1773 mortality outcomes. Six different vasopressors, given alone or in combination, were studied in 12 different comparisons.All 28 studies reported mortality outcomes; 12 studies reported length of stay. Investigators reported other morbidity outcomes in a variable and heterogeneous way. No data were available on quality of life nor on anxiety and depression outcomes. We classified 11 studies as having low risk of bias for the primary outcome of mortality; only four studies fulfilled all trial quality criteria.In summary, researchers reported no differences in total mortality in any comparisons of different vasopressors or combinations in any of the pre-defined analyses (evidence quality ranging from high to very low). More arrhythmias were observed in participants treated with dopamine than in those treated with norepinephrine (high-quality evidence). These findings were consistent among the few large studies and among studies with different levels of within-study bias risk. AUTHORS' CONCLUSIONS: We found no evidence of substantial differences in total mortality between several vasopressors. Dopamine increases the risk of arrhythmia compared with norepinephrine and might increase mortality. Otherwise, evidence of any other differences between any of the six vasopressors examined is insufficient. We identified low risk of bias and high-quality evidence for the comparison of norepinephrine versus dopamine and moderate to very low-quality evidence for all other comparisons, mainly because single comparisons occasionally were based on only a few participants. Increasing evidence indicates that the treatment goals most often employed are of limited clinical value. Our findings suggest that major changes in clinical practice are not needed, but that selection of vasopressors could be better individualised and could be based on clinical variables reflecting hypoperfusion.

"Push as hard as you can" instruction for telephone cardiopulmonary resuscitation: a randomized simulation study.

BACKGROUND: The medical priority dispatch system (MPDS®) assists lay rescuers in protocol-driven telephone-assisted cardiopulmonary resuscitation (CPR). OBJECTIVE: Our aim was to clarify which CPR instruction leads to sufficient compression depth. METHODS: This was an investigator-blinded, randomized, parallel group, simulation study to investigate 10 min of chest compressions after the instruction "push down firmly 5 cm" vs. "push as hard as you can." Primary outcome was defined as compression depth. Secondary outcomes were participants exertion measured by Borg scale, provider's systolic and diastolic blood pressure, and quality values measured by the skill-reporting program of the Resusci(®) Anne Simulator manikin. For the analysis of the primary outcome, we used a linear random intercept model to allow for the repeated measurements with the intervention as a covariate. RESULTS: Thirteen participants were allocated to control and intervention. One participant (intervention) dropped out after min 7 because of exhaustion. Primary outcome showed a mean compression depth of 44.1 mm, with an inter-individual standard deviation (SDb) of 13.0 mm and an intra-individual standard deviation (SDw) of 6.7 mm for the control group vs. 46.1 mm and a SDb of 9.0 mm and SDw of 10.3 mm for the intervention group (difference: 1.9; 95% confidence interval -6.9 to 10.8; p = 0.66). Secondary outcomes showed no difference for exhaustion and CPR-quality values. CONCLUSIONS: There is no difference in compression depth, quality of CPR, or physical strain on lay rescuers using the initial instruction "push as hard as you can" vs. the standard MPDS(®) instruction "push down firmly 5 cm."

Exposure to carbon monoxide for patients and providers in an urban emergency medical service.

BACKGROUND: Carbon monoxide (CO) poisoning poses danger to both patients and emergency medical services (EMS) personnel, as its symptoms are nonspecific and EMS is currently not equipped to detect CO in ambient air. OBJECTIVE: We aimed to assess the degree of non-fire-related CO exposure at the high-volume EMS system of a city with 2 million inhabitants. METHODS: The EMS system was equipped with handheld CO detectors (Dräger Pac 3500), which were added to EMS standard backpacks and had to be carried to the patient at all times. During a period of one year, all alarms by those devices were recorded, sources of CO were confirmed by the fire department, and hospital follow-up was conducted for both patients and exposed EMS staff. RESULTS: During the study period, there were 40 alarms, including two false alarms. Alarms occurred during the whole year, with a peak during the winter months. The median ambient CO concentration was 167 parts per million; gas heating systems were the main source of CO. One hundred ten patients and 108 EMS personnel were exposed. One hundred fifteen persons, including 22 EMS staff, had to be hospitalized, which represents one out of 1,000 total EMS patients. CONCLUSIONS: Carbon monoxide poisoning was found to be a significant matter for a high-volume EMS system. Handheld CO detectors helped in identifying those cases. Key words: carbon monoxide; emergency care, prehospital; equipment and supplies; poisoning.

Airway management of adult patients without trauma in an ED led by internists.

BACKGROUND: Airway management is a key competence in emergency medicine. Patients heavily differ from those in the operating room. They are acutely ill by definition and usually not fasting. Evaluation of risk factors is often impossible. Current literature primarily originates from countries where emergency medicine is an independent specialty. We evaluated intubations in a high-volume emergency department run by internists and comprising its own distinctive intensive care unit. METHODS: In this prospective, noncontrolled, observational study, we continuously documented all intubations performed at the emergency department. We analyzed demographic, medical, and staff-related factors predicting difficulties during intubation using logistic regression models. RESULTS: For 73 months, 660 cases were included, 69 (10.5%) of them were without any induction therapy. Two hundred fifty-two (38.2%) patients were female, and their mean age was 59 ± 17 years. Three hundred four (49.9%) had an initial Glasgow Coma Scale of 3. Leading indications were respiratory insufficiency (n = 246; 37.3%), resuscitation (n = 172; 26.1%), and intracranial hemorrhage (n = 75; 11.4%). First attempt was successful in 465 cases (75.1%); alternative airway devices were used in 22 cases (3.3%). Time from the first intubation attempt to a validated airway was 1 minute (interquartile range, 0-2 minutes). Physicians' experience and anatomical risk factors were associated with failure at the first attempt, prolonged intubation, and the need for alternative devices. CONCLUSIONS: Airway management at the emergency department possesses a high potential of failure. Experience seems to be the key to success.

Unrecognized carbon monoxide poisoning leads to a multiple-casualty incident.

BACKGROUND: Carbon monoxide (CO) is regarded as a leading cause of morbidity and mortality. It endangers not only patients, but also health care professionals, especially emergency medical services (EMS) personnel because CO exposure is often unknown at the time EMS is called. OBJECTIVE: Our objective was to report a case of unrecognized CO exposure during the treatment of a patient that finally led to the hospitalization of 11 EMS personnel. CASE REPORT: A 71-year-old man was found unconscious in the basement of his house. EMS was called and, due to ST-segment elevations on electrocardiogram, the patient was treated for acute coronary syndrome. Unknown to EMS personnel, ongoing CO exposure was the cause of the patient's symptoms. EMS staff finally had to be evacuated by firefighters, and a total of 12 persons, including the initial patient, had to be hospitalized. CONCLUSIONS: In the prehospital setting, hazardous environments always have to be considered as potential causes of a patient's altered status. Together with the correct use of modern equipment, such as permanently switched-on CO detectors, this can help avoid harm to both patients and staff.

Hypothermia for neuroprotection in adults after cardiopulmonary resuscitation.

BACKGROUND: Good neurologic outcome after cardiac arrest is hard to achieve. Interventions during the resuscitation phase and treatment within the first hours after the event are critical. Experimental evidence suggests that therapeutic hypothermia is beneficial, and a number of clinical studies on this subject have been published. This review was originally published in 2009. OBJECTIVES: We performed a systematic review and meta-analysis to assess the effectiveness of therapeutic hypothermia in patients after cardiac arrest. Neurologic outcome, survival and adverse events were our main outcomes. We aimed to perform individual patient data analysis, if data were available, and to form subgroups according to the cardiac arrest situation. SEARCH METHODS: We searched the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2001, Issue 7); MEDLINE (1971 to July 2011); EMBASE (1987 to July 2011); CINAHL (1988 to July 2011); PASCAL (2000 to July 2011); and BIOSIS (1989 to July 2011). The original search was performed in January 2007. SELECTION CRITERIA: We included all randomized controlled trials assessing the effectiveness of therapeutic hypothermia in patients after cardiac arrest, without language restrictions. Studies were restricted to adult populations cooled with any cooling method, applied within six hours of cardiac arrest. DATA COLLECTION AND ANALYSIS: Validity measures, the intervention, outcomes and additional baseline variables were entered into a database. Meta-analysis was only done for a subset of comparable studies with negligible heterogeneity. For these studies, individual patient data were available. MAIN RESULTS: We included four trials and one abstract reporting on 481 patients in the systematic review. The updated search resulted in no new studies to include. Quality of the included studies was good in three out of five studies. For the three comparable studies on conventional cooling methods all authors provided individual patient data. With conventional cooling methods, patients in the hypothermia group were more likely to reach a best cerebral performance categories (CPC) score of one or two (five point scale: 1 = good cerebral performance, to 5 = brain death) during the hospital stay (individual patient data; RR 1.55; 95% CI 1.22 to 1.96) and were more likely to survive to hospital discharge (individual patient data; RR 1.35; 95% CI 1.10 to 1.65) compared to standard post-resuscitation care. Across all studies, there was no significant difference in reported adverse events between hypothermia and control. AUTHORS' CONCLUSIONS: Conventional cooling methods to induce mild therapeutic hypothermia seem to improve survival and neurologic outcome after cardiac arrest. Our review supports the current best medical practice as recommended by the International Resuscitation Guidelines.

An electrocardiogram technician improves in-hospital first medical contact-to-electrocardiogram times: a cluster randomized controlled interventional trial.

BACKGROUND: In the case of chest pain, the current guidelines require electrocardiogram (ECG) recording and patient assessment within 10 minutes upon arrival in the emergency department. METHODS: We investigated the effect of an ECG technician (ECG-T) on in-hospital first medical contact-to-ECG times (iFMC-to-ECG) investigated in a cluster randomized, controlled trial. Allocation of intervention was concealed. Staff satisfaction and feasibility was defined as a secondary outcome. Delays between ECG and the availability of an emergency physician and the assessment of ECG were additionally evaluated. RESULTS: A total of 163 (44 clusters) and 191 (47 clusters) patients were allocated to control and intervention, respectively. Twenty-seven (17%) of 163 patients in the control group vs 110 (58%) of 191 patients in the intervention group received ECG registration within 10 minutes (risk ratio, 3.40 [2.24-5.15]; P < .001). The iFMC-to-ECG time was 23 (95% confidence interval [CI], 20-27) minutes for the control group vs 9 (95% CI, 8-11) minutes for the intervention group (P < .001). Nursing staff judged the feasibility of intervention with a median of 1 (interquartile range [IQR], 1-1 (on a scale of 1 [best] to 5 [worst]), perceived workload alleviation with a median of 1 (IQR, 1-1), and improvement of quality of care with a median of 1 (IQR, 1-2). The ECG-to-EP time was 78 (95% CI, 64-92) seconds, and diagnosis was made within 17 (95% CI, 16-18) seconds. CONCLUSIONS: Delays of iFMC-to-ECG can be effectively addressed by implementation of an ECG-T. The service of an ECG-T is feasible and improves staff satisfaction. Both ECG-to-EP time and ECG assessment constitute no relevant delay.

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.

Accuracy of noninvasive multiwave pulse oximetry compared with carboxyhemoglobin from blood gas analysis in unselected emergency department patients.

STUDY OBJECTIVE: Accurate and timely diagnosis of carbon monoxide (CO) poisoning is difficult because of nonspecific symptoms. Multiwave pulse oximetry might facilitate the screening for occult poisoning by noninvasive measurement of carboxyhemoglobin (COHb), but its reliability is still unknown. We assess bias and precision of COHb oximetry compared with the criterion standard blood gas analysis. METHODS: This was a prospective diagnostic accuracy study according to STARD (Standards for the Reporting of Diagnostic accuracy studies) criteria, performed at a tertiary care hospital emergency department. We included all patients for whom both invasive and noninvasive measurement within 60 minutes was available, regardless of their complaints, during a 1-year period. RESULTS: One thousand five hundred seventy-eight subjects were studied, of whom 17 (1.1%) received a diagnosis of CO poisoning. In accordance with this limited patient cohort, we found a bias of 2.99% COHb (1.50% for smokers, 4.33% for nonsmokers) and a precision of 3.27% COHb (2.90% for smokers, 2.98% for nonsmokers), limits of agreement from -3.55% to 9.53% COHb (-4.30% to 7.30% for smokers, -1.63% to 10.29% for nonsmokers). Upper limit of normal cutoff of 6.6% COHb had the highest sensitivity in screening for CO poisoning. Smoking status and COHb level had the most influence on the deviation between measurements. CONCLUSION: Multiwave pulse oximetry was found to measure COHb with an acceptable bias and precision. These results suggest it can be used to screen large numbers of patients for occult CO poisoning.

Vasopressors for hypotensive shock.

BACKGROUND: Initial goal directed resuscitation for shock usually includes the administration of intravenous fluids, followed by initiating vasopressors. Despite obvious immediate effects of vasopressors on haemodynamics their effect on patient relevant outcomes remains controversial. This review was originally published in 2004 and was updated in 2011. OBJECTIVES: Our primary objective was to assess whether particular vasopressors reduce overall mortality, morbidity, and health-related quality of life. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 2), MEDLINE, EMBASE, PASCAL BioMed, CINAHL, BIOSIS, and PsycINFO (from inception to March 2010). The original search was performed in November 2003. We also asked experts in the field and searched meta-registries for ongoing trials. SELECTION CRITERIA: Randomized controlled trials comparing various vasopressor regimens for hypotensive shock. DATA COLLECTION AND ANALYSIS: Two authors abstracted data independently. Disagreement between the authors was discussed and resolved with a third author. We used a random-effects model for combining quantitative data. MAIN RESULTS: We identified 23 randomized controlled trials involving 3212 patients, with 1629 mortality outcomes. Six different vasopressors, alone or in combination, were studied in 11 different comparisons.All 23 studies reported mortality outcomes; length of stay was reported in nine studies. Other morbidity outcomes were reported in a variable and heterogeneous way. No data were available on quality of life or anxiety and depression outcomes. We classified 10 studies as being at low risk of bias for the primary outcome mortality; only four studies fulfilled all trial quality items.In summary, there was no difference in mortality in any of the comparisons between different vasopressors or combinations. More arrhythmias were observed in patients treated with dopamine compared to norepinephrine. Norepinephrine versus dopamine, as the largest comparison in 1400 patients from six trials, yielded almost equivalence (RR 0.95, 95% confidence interval 0.87 to 1.03). Vasopressors used as add-on therapy in comparison to placebo were not effective either. These findings were consistent among the few large studies as well as in studies with different levels of within-study bias risk. AUTHORS' CONCLUSIONS: There is some evidence of no difference in mortality between norepinephrine and dopamine. Dopamine appeared to increase the risk for arrhythmia. There is not sufficient evidence of any difference between any of the six vasopressors examined. Probably the choice of vasopressors in patients with shock does not influence the outcome, rather than any vasoactive effect per se. There is not sufficient evidence that any one of the investigated vasopressors is clearly superior over others.

Accelerated management of patients with ST-segment elevation myocardial infarction in the ED.

PURPOSES: The objective of this study was to evaluate improvement opportunities in the emergency department for timely ST-segment elevation myocardial infarction management and evaluated the new process flow. BASIC PROCEDURES: In a prospective study, we compared time from door to cath laboratory before and after implementation of a new ST-segment elevation myocardial infarction (STEMI) protocol. The new protocol included a blend of strategies to reduce door to cath laboratory time. MAIN FINDINGS: We included 55 patients. After implementing a new STEMI protocol, we included 54 patients. Time to cath laboratory was 21 (interquartile range, 9-40) minutes before and 10 (interquartile range 5-25) minutes after initiation of the new protocol (P = .02). A door to cath laboratory time less than 15 minutes was reached in 36% of our patients in phase 1 and in 61% in phase 2 (odds ratio; 0.36, 95% confidence interval, 0.16-0.81; P = .01). PRINCIPAL CONCLUSION: Simple changes in organizational strategies resulted in a significantly faster care for patients with acute uncomplicated STEMI.

Victim of carbon monoxide poisoning identified by carbon monoxide oximetry.

BACKGROUND: Carbon monoxide (CO) is known as a leading cause of unintentional poisoning death in many countries. Diagnosis is usually made by measuring carboxyhemoglobin (COHb), but due to the non-specific symptoms, the crucial step is considering CO poisoning. A possible solution might be screening emergency department (ED) patients. A cutaneous sensor that measures oxygen and CO saturation simultaneously could accomplish that. OBJECTIVES: We report a case in which CO-oximetry screening helped to identify CO poisoning in a patient with otherwise non-specific complaints presenting to a busy university hospital ED. CASE REPORT: A 53-year-old woman presented to our ED, reporting non-specific but common symptoms including emesis and diarrhea, one-sided headache, paresthesia, and palpitations. Whereas conventional pulse oximetry showed normal results, a COHb level of 28% was measured using a CO-oximeter. This allowed a diagnosis of CO poisoning to be made at admission. The patient was treated with 100% oxygen continuous positive airway pressure ventilation, and CO washout was monitored continuously and non-invasively. In the meantime, the local fire department was alerted and found a malfunctioning water heater as the source of CO in the patient's residence. As COHb fell to normal levels and the patient reported feeling well, she was discharged the next day. CONCLUSION: CO-oximetry served as a powerful tool in both identifying and monitoring a CO-poisoned patient in a busy ED. Future studies should address possible sources of error using this method on a long-term basis and its level of acceptance by ED staff.

Safety, feasibility, and hemodynamic and blood flow effects of active compression-decompression of thorax and abdomen in patients with cardiac arrest.

OBJECTIVE: During closed chest compression for cardiac arrest, any increase in coronary perfusion pressure accounts for a proportional increase in myocardial blood flow and therefore the resuscitability of the patient. The objectives of this study were to evaluate the safety, feasibility, and hemodynamic effects of phased chest and abdominal compression-decompression and to compare it with mechanical chest compression during cardiopulmonary resuscitation. DESIGN: In this prospective, single-center, phase II study, we compared patients treated with the Datascope Lifestick Resuscitator with patients who had been treated with mechanical precordial compression. SETTING: Emergency department of a tertiary care university hospital. PATIENTS: We included 31 patients with cardiac arrest who had received cardiopulmonary resuscitation in the emergency department. INTERVENTIONS: The Lifestick device was used in 20 patients. In 11 patients, mechanical chest compression with the Thumper device was used as a control intervention. MEASUREMENTS AND MAIN RESULTS: We evaluated the safety, feasibility, and hemodynamic effects of both interventions and observed, with the help of echocardiography, the mechanisms through which blood flow was generated. We found no significant difference between the use of the Lifestick device and standard chest compression with the Thumper device in resuscitations. Most operators regarded the Lifestick as a feasible alternative to the Thumper. We could observe a mean increase in coronary perfusion pressure of 9.33 mm Hg (interquartile range, 1.96-14.36; p = .08) and an increase of end-tidal CO2 of 10 mm Hg (interquartile range, 5-16; p = .003) (1333Pa [interquartile range, 665-2133]) during resuscitation with the Lifestick compared with using the Thumper. CONCLUSION: In this preliminary study, resuscitation with the Lifestick was found to be safe and feasible. The design of the study and small number of patients included in it limit the conclusions about the hemodynamic effects of the Lifestick.

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.

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.