Advanced Life Support Care Research Articles

Intact neurological status after induced therapeutic hypothermia in cardiac arrest

Introduction: Cardiac arrest patients in whom return of spontaneous circulation (ROSC) is achieved after resuscitation frequently develop irreversible neurological impairments owing to hypoxic injury and reperfusion induced cell death. Therapeutic hypothermia has become a standard strategy in specific unconscious adult patients with ROSC after out-of-hospital cardiac arrest (OHCA) as per American Heart Association (AHA) guidelines. Case Report: A 48-year-old South Asian male arrived to our emergency department with 20 minutes duration of OHCA with no basic life support (BLS) measures en route to hospital. His initial rhythm was ventricular fibrillation and he had ROSC after 13 minutes of cardiopulmonary resuscitation (CPR) and subsequently underwent therapeutic hypothermia for 24 hours and recovered completely without neurological impairment after eight days of incident. Conclusion: Therapeutic hypothermia in eligible cardiac arrest patients is an important component of the post-cardiac arrest care in the AHA chain of survival. The AHA chain of survival is a chain of five interdependent links for cardiac arrest and comprises early recognition, early CPR, early defibrillation, early advanced cardiac life support and post-cardiac arrest care. It has substantial benefits on patient outcome. The ease of administration and positive clinical outcome should encourage other medical professionals to avail this modality.

Fatal Cesium Chloride Toxicity After Alternative Cancer Treatment

Cesium chloride (CsCl) is sold as a treatment for several types of cancers. The purported mechanism of action is alkalinization of relatively acidic neoplastic cells. The efficacy of CsCl has not been demonstrated in controlled experiments. Oral and intravenous CsCl use has been associated with seizures, cardiotoxicity, syncope, and death. Although intratumoral treatment with various antineoplastic agents is described, no cases of intratumoral cancer treatment with CsCl have been found in the medical literature. The case described here appears to be of the first reported patient with CsCl toxicity secondary to subcutaneous exposure after attempted intratumoral injection. A 61-year-old woman presented in cardiac arrest 20 hours after injecting 9 mL of an oral CsCl preparation around a mass in her breast. She had been taking the CsCl orally for approximately 1 year to treat her breast mass. The patient had a headache and nausea for several hours after injection and then experienced ventricular tachycardia arrest at home. She received advanced cardiac life support care and multiple antiarrhythmic medications and underwent electrical cardioversion early in the course of the arrest. After stabilization, her electrocardiogram revealed QT interval prolongation to >700 milliseconds. Upon discovery of her CsCl exposure, she was treated with Prussian blue. Her initial whole blood cesium level was 100,000 μg/L (reference range <10 μg/L). Her QT prolongation resolved after several days, but she experienced no meaningful postarrest neurologic recovery and died at home less than a week after exposure. CsCl is sold as an alternative treatment for cancer. There is no demonstrable efficacy, and clear evidence shows life-threatening toxicity. Reported here is a case of fatal CsCl toxicity after attempted intratumoral injection.

Out‐of‐hospital cardiac arrest: 10 years of progress in research and treatment

Cardiac disease is the most common cause of mortality in Western countries, with most deaths due to out-of-hospital cardiac arrest (OHCA). In Sweden, 5000-10000 OHCAs occur annually. During the last decade, the time from cardiac arrest to start of cardiopulmonary resuscitation (CPR) and defibrillation has increased, whereas survival has remained unchanged or even increased. Resuscitation of OHCA patients is based on the 'chain-of-survival' concept, including early (i) access, (ii) CPR, (iii) defibrillation, (iv) advanced cardiac life support and (v) post-resuscitation care. Regarding early access, agonal breathing, telephone-guided CPR and the use of 'track and trigger systems' to detect deterioration in patients' condition prior to an arrest are all important. The use of compression-only CPR by bystanders as an alternative to standard CPR in OHCA has been debated. Based on recent findings, guidelines recommend telephone-guided chest compression-only CPR for untrained rescuers, but trained personnel are still advised to give standard CPR with both compressions and ventilation, and the method of choice for this large group remains unclear and demands for a randomized study. Data have shown the benefit of public access defibrillation for dispatched rescuers (e.g. police and fire fighters) but data are not as strong for the use of automated defibrillators (AEDs) by trained or untrained rescuers. Postresuscitation, use of therapeutic hypothermia, the importance of specific prognostic survival factors in the intensive care unit and the widespread use of percutaneous coronary intervention have all been considered. Despite progress in research and improved treatment regimens, most patients do not survive OHCA. Particular areas of interest for improving survival include (i) identification of high-risk patients prior to their arrest (e.g. early warning symptoms and genes); (ii) increased use of bystander CPR training (e.g. in schools) and simplified CPR techniques; (iii) better identification of high-incidence sites and better recruitment of AEDs (via mobile phone solutions?); (iv) improved understanding of the use of therapeutic hypothermia; (v) determining which patients should undergo immediate coronary angiography on hospital admission; and (vi) clarifying the importance of extracorporeal membrane oxygenation during CPR.

Safety and Efficacy of Prehospital Diltiazem

Introduction: Very few studies exist on the use of diltiazem in the prehospital setting. Some practitioners believe this medication is prone to causing hypotension in this setting. Our goals were to determine whether the prehospital administration of diltiazem induced hypotension and to evaluate the efficacy of the drug.Methods: Our two-tiered system is located in a suburban region of New Jersey with advanced life support (ALS) care provided by fly-car units. The ALS units do not transport patients, and all of them are hospital based. The ALS providers are employed by the hospital system. In New Jersey, all ALS care requires online medical control, including the administration of diltiazem. We retrospectively reviewed patient care records for those who were believed to be in rapid atrial fibrillation and were given diltiazem in a suburban emergeny medical services system over a 22-month period. We examined the differences between heart rate (HR) and blood pressure (BP) on the initial evaluation and on arrival to the emergency department (ED). A hypotensive response was defined as a final systolic BP (SBP) less than 90 mmHg and a drop in SBP of at least 10 mmHg. Diltiazem was considered effective if the ED HR was <100 beats per minute (bpm) or if it decreased ≥20%.Results: During the study period, 26,979 patients were transported. Of these patients, 2,488 had a documented rhythm of atrial fibrillation or atrial flutter. Of the 320 patients who received diltiazem, 42 patient encounters were excluded for incomplete data, yielding 278 patients for analysis. The average initial SBP was 139 mmHg and the average diastolic BP was 84 mmHg. The average diltiazem dosage was 16.7 mg. Two patients became hypotensive. The average initial HR was 154 bpm. On arrival to the ED, 33% of the patients had an HR < 100 bpm and 69% had a drop in HR ≥ 20%. The overall efficacy of prehospital diltiazem was 73%.Conclusion: In the prehospital setting, diltiazem is associated with a very low rate of hypotension and appears to be effective in decreasing HR adequately. Prospective studies are needed to confirm these findings.

A pan-European study of capabilities to manage mass casualties from the release of chemical agents: The MASH project

The European Union (EU) Mass Casualties and Health (MASH) project that ran between 2008 and 2010 was designed to study the management of mass casualties from chemical and radiological releases and associated health implications. One area of study for this project concerned arrangements within EU Member States for the management of mass casualties following a chemical release. This was undertaken via a confidential online questionnaire that was sent to selected points of contact throughout the EU. Responses were obtained from 18 states from respondents holding senior positions in chemical planning and incident response. Information gathered shows a lack of uniformity within the EU about the organization of responses to chemical releases and the provision of medical care. This article presents the overall findings of the study demonstrating differences between countries on planning and organization, decontamination, prehospital emergency medical responses, clinical diagnoses, and therapy and aftercare. Although there may be an understandable reluctance from national respondents to share information on security and other grounds, the findings, nevertheless, revealed substantial differences between current planning and operational responses within the EU states for the management of mass chemical casualties. The existing international networks for response to radiation incidents are not yet matched by equivalent networks for chemical responses yet sufficient information was available from the study to identify potential deficiencies, identify common casualty management pathways, and to make recommendations for future operations within the EU. Improvements in awareness and training and the application of modern information and communications will help to remedy this situation. Specialized advanced life support and other medical care for chemical casualties appear lacking in some countries. A program of specialized training and action are required to apply the findings revealed by the MASH study into a unified cross-border emergency medical response.

RECOVER evidence and knowledge gap analysis on veterinary CPR. Part 7: Clinical guidelines

To present a series of evidence-based, consensus guidelines for veterinary CPR in dogs and cats. Standardized, systematic evaluation of the literature, categorization of relevant articles according to level of evidence and quality, and development of consensus on conclusions for application of the concepts to clinical practice. Questions in five domains were examined: Preparedness and Prevention, Basic Life Support, Advanced Life Support, Monitoring, and Post-Cardiac Arrest Care. Standardized worksheet templates were used for each question, and the results reviewed by the domain members, by the RECOVER committee, and opened for comments by veterinary professionals for 4 weeks. Clinical guidelines were devised from these findings and again reviewed and commented on by the different entities within RECOVER as well as by veterinary professionals. Academia, referral practice and general practice. A total of 74 worksheets were prepared to evaluate questions across the five domains. A series of 101 individual clinical guidelines were generated. In addition, a CPR algorithm, resuscitation drug-dosing scheme, and postcardiac arrest care algorithm were developed. Although many knowledge gaps were identified, specific clinical guidelines for small animal veterinary CPR were generated from this evidence-based process. Future work is needed to objectively evaluate the effects of these new clinical guidelines on CPR outcome, and to address the knowledge gaps identified through this process.

Cardiopulmonary cerebral resuscitation: advanced life support and post-resuscitation care

Cardiopulmonary arrest (CPA) is the cessation of spontaneous ventilation and systemic perfusion, which, if not rapidly detected and treated, leads to hypoxia and death. Cardiopulmonary cerebral resuscitation (CPCR) is a technique employed to reverse CPA. The goal of CPCR is not only to achieve return of spontaneous circulation (ROSC) but to ensure survival following discharge from hospital with a good quality of life. This article provides a review of how to provide effective advanced life support after basic life support has been initiated, while highlighting the importance of post-resuscitation care in order to optimize the chance of the patient being discharged from hospital. This review of veterinary and human literature aims to suggest some guidelines for nurses to follow.

The pending loss of advanced life support paramedics in South Africa

Background In 2008 South Africa (SA) had 1631 registered advanced life support (ALS) paramedics to provide pre-hospital advanced life support care to a population of approximately 50 million. Compared to globally accepted ratios, the number of ALS paramedics in South Africa can be considered as grossly inadequate. This current shortage may be ascribed to migration. However, the extent and nature of this migration, the factors that have contributed to them leaving the country and the existence or effectiveness of implemented strategies that attempt to manage migration of SA ALS paramedic is not known for sure. Methods The study consisted of a two-phase mixed method descriptive survey. A subset of SA ALS paramedics made up the study population. Quantitative data (Phase One) was obtained from a web-based survey distributed to the accessible population (N=97). Thereafter, qualitative data (Phase Two) was gathered through in-depth interviews with selected information rich participants (n=10) also from within the accessible population. Through methodological triangulation, data from Phase One and Phase Two were integrated to obtain an in-depth understanding of South African ALS paramedic migration. In addition, the study investigated whether strategies that attempted to manage migration of SA ALS paramedics existed, and if they did, how effective have they been. Result Fifty-one of 97 (53%) ALS paramedics responded to the questionnaire in Phase One. Of those, 24 (47.1%) were found to be working inside South Africa, while 27 (52.9%) were working outside South Africa. Working conditions, physical security, and economic considerations were ranked as the top three major factors contributing to the decision or intended decision to migrate. Initiatives to manage the shortage of ALS paramedics in the public sector EMS do exist; however, it appears to be inadequate at its current rate of progress. Conclusion This study suggests that ALS paramedics in SA are leaving to find work outside the country because of working conditions, physical security, and economic considerations. The current measures to manage migration appear to be ineffective, indicating that new or additional strategies to manage migration of ALS paramedics in SA may be required.

272 Imposed Educational Requirements for Out-of-Hospital Providers Relating to Patients With Autism Spectrum Disorder

Recently there has been increased publicity about Autism Spectrum Disorder (ASD) and a political push for more educational programs for health care providers. In some states, government regulations required that EMS providers take annual continuing education courses related to ASD because it is thought that patients with this disorder present unique challenges to EMS providers. To our knowledge, there are no studies analyzing the out-of-hospital evaluation and management of patients with ASD. We sought to identify and analyze the out-of-hospital advanced life support (ALS) care of patients with ASD.

Kindernotfälle in der Luftrettung – eine epidemiologische Studie zur Versorgung in Österreich

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. 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). 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). 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.

Neurologic Recovery Following Prolonged Out-of-Hospital Cardiac Arrest With Resuscitation Guided by Continuous Capnography

A 54-year-old man with no known cardiac disease collapsed outdoors in a small rural community. The cardiac arrest was witnessed, and immediate cardiopulmonary resuscitation was begun by a bystander and a trained first responder who was nearby. The patient was moved into a building across the street for continued resuscitation. First responders arrived with an automated external defibrillator, and ventricular fibrillation was documented. First responders delivered 6 defibrillation shocks, 4 of which transiently restored an organized electrocardiographic rhythm but with no pulse at any time. Additional emergency medical services personnel from nearby communities and an advanced life support (ALS) flight crew arrived. The flight crew initiated ALS care. The trachea was intubated, ventilation controlled, and end-tidal carbon dioxide tension continuously monitored. Antiarrhythmic and inotropic drugs were administered intravenously. An additional 6 shocks were delivered using the ALS defibrillator. End-tidal carbon dioxide measurements confirmed good pulmonary blood flow with chest compressions, and resuscitation was continued until a stable cardiac rhythm was restored after 96 minutes of pulselessness. The patient was transported by helicopter to the hospital. He was in cardiogenic shock but maintained a spontaneous circulation. Coronary angiography confirmed a left anterior descending coronary artery thrombotic occlusion that was treated successfully. After hospital admission, the patient required circulatory and ventilatory support and hemodialysis for acute renal failure. He experienced a complete neurologic recovery to his pre-cardiac arrest state. To our knowledge, this is the longest duration of pulselessness in an out-of-hospital arrest with a good outcome. Good pulmonary blood flow was documented throughout by end-tidal carbon dioxide measurements.

Delayed Prehospital Implementation of the 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiac Care

Introduction. In 2005, the American Heart Association (AHA) released guidelines to improve survival rates from out-of-hospital cardiac arrest (OHCA). Objective. To determine if, and when, emergency medical services (EMS) agencies participating in the Resuscitation Outcomes Consortium (ROC) implemented these guidelines. Methods. We contacted 178 EMS agencies and completed structured telephone interviews with 176 agencies. The survey collected data on specific treatment protocols before and after implementation of the 2005 guidelines as well as the date of implementation crossover (the “crossover date”). The crossover date was then linked to a database describing the size, type, and structure of each agency. Descriptive statistics and regression were used to examine patterns in time to crossover. Results. The 2005 guidelines were implemented by 174 agencies (99%). The number of days from guideline release to implementation was as follows: mean 416 (standard deviation 172), median 415 (range 49–750). There was no difference in time to implementation in fire-based agencies (mean 432), nonfire municipal agencies (mean 365), and private agencies (mean 389, p = 0.31). Agencies not providing transport took longer to implement than agencies that transported patients (463 vs. 384 days, p = 0.004). Agencies providing only basic life support (BLS) care took longer to implement than agencies who provided advanced life support (ALS) care (mean 462 vs. 397 days, p = 0.03). Larger agencies (>10 vehicles) were able to implement the guidelines more quickly than smaller agencies (mean 386 vs. 442 days, p = 0.03). On average, it took 8.9 fewer days to implement the guidelines for every 50% increase in EMS-treated runs/year to which an agency responded. Conclusion. ROC EMS agencies required an average of 416 days to implement the 2005 AHA guidelines for OHCA. Small EMS agencies, BLS-only agencies, and nontransport agencies took longer than large agencies, agencies providing ALS care, and transport agencies, respectively, to implement the guidelines. Causes of delays to guideline implementation and effective methods for rapid EMS knowledge translation deserve investigation.

Paramedic Intercepts with Basic Life Support Ambulance Services in Rural Minnesota

In rural Minnesota, it is common for paramedics providing advanced life support (ALS) to rendezvous with ambulances providing only basic life support (BLS). These "intercepts" presumably allow for a higher level of care when patients have certain problems or need ALS interventions. The aim of this study was to review and understand the frequency of paramedic intercepts with regard to the actual care rendered and transport urgency (lights and sirens vs. none). All paramedic intercepts occurring between January 2003 and December 2007 for one multi-site emergency medical services (EMS) provider were reviewed for ALS interventions and treatments provided. In addition, the urgency of responses to the dispatch call or "intercept" and transport to a receiving facility were analyzed. During the study period, 1,675 paramedic intercepts occurred and were reviewed. The ALS ambulances responded to the dispatch emergently (lights and sirens) in 97.5% of intercepts (1,633), but emergently transported only 24.2% of the patients (405). Paramedics performed no interventions above BLS levels in 11.6% (194) of the cases. Of the remaining 1,481 patients who received ALS interventions, 955 (64.4%) received no treatment or diagnostic testing other than electrocardiographic monitoring, intravenous access, or both. A significant discrepancy between emergent responses and actual ALS care rendered during intercept calls was demonstrated. Given the significant rate of EMS worker fatalities and transferable patient care costs, further study is needed to determine whether costs and safety are potentially improved by decreasing emergent responses. Future directions include developing or emulating Medical Priority Dispatch System triage protocols for advanced services providing intercepts. In addition, further study of patient outcomes between intercept and non-intercept cases is necessary.

Improving outcome after out-of-hospital cardiac arrest by strengthening weak links of the local Chain of Survival; quality of advanced life support and post-resuscitation care

Background Survival after out-of-hospital cardiac arrest (OHCA) depends on a well functioning Chain of Survival. We wanted to assess if targeted attempts to strengthen the weak links of our local chain; quality of advanced life support (ALS) and post-resuscitation care, would improve outcome. Materials and methods Utstein data from all OHCAs in Oslo during three distinct 2-year time periods 1996–1998, 2001–2003 and 2004–2005 were collected. Before the second period the local ALS guidelines changed with increased focus on good quality chest compressions with minimal pauses, while standardized post-resuscitation care including goal directed therapy with therapeutic hypothermia and percutaneous coronary intervention was added in the third period. Additional a priori sub-group analyses of arrests with cardiac aetiology as well as bystander witnessed ventricular fibrillation/tachycardia (VF/VT) arrests with cardiac aetiology were performed. Results ALS was attempted in 454, 449, and 417 patients with OHCA in the first, second and last time period, respectively. From the first to the third period VF/VT arrests declined (40% vs. 33%, p = 0.039) and fewer arrests were witnessed (80% vs. 72%, p = 0.022) and response intervals increased (7 ± 4 to 9 ± 4 min, p < 0.001). Overall survival increased from 7% (first period) to 13% (last period), p = 0.002, and survival in the sub-group of bystander witnessed VF/VT arrests with cardiac aetiology increased from 15% (first period) to 35% (last period), p = 0.001. Conclusions Survival after OHCA was increased after improving weak links of our local Chain of Survival, quality of ALS and post-resuscitation care.

Clinical Decision Rules for Termination of Resuscitation in Out-of-Hospital Cardiac Arrest

Background: Out-of-hospital cardiac arrest (OHCA) has a low probability of survival to hospital discharge. Four clinical decision rules (CDRs) have been validated to identify patients with no probability of survival. Three of these rules focus on exclusive prehospital basic life support care for OHCA, and two of these rules focus on prehospital advanced life support care for OHCA. Clinical Question: Can a CDR for the termination of resuscitation identify a patient with no probability of survival in the setting of OHCA? Evidence Review: Six validation studies were selected from a PubMed search. A structured review of each of the studies is presented. Results: In OHCA receiving basic life support care, the BLS-TOR (basic life support termination of resuscitation) rule has a positive predictive value for death of 99.5% (95% confidence interval 98.9–99.8%), and decreases the transportation of all patients by 62.6%. This rule has been appropriately validated for widespread use. In OHCA receiving advanced life support care, no current rule has been appropriately validated for widespread use. Conclusions: The BLS-TOR rule is a simple rule that identifies patients who will not survive OHCA. Further research is required to identify similarly robust CDRs for patients receiving advanced life support care in the setting of OHCA.

Validation of a universal prehospital termination of resuscitation clinical prediction rule for advanced and basic life support providers

Prehospital termination of resuscitation rules have been derived for Emergency Medical Technician-Paramedics providing advanced life support care and defibrillation-only Emergency Medical Technicians providing basic life support care. We sought to externally validate each rule on a prospective cohort of prehospital cardiac arrest patients to determine if either rule could be proposed as a universal prehospital termination of resuscitation rule. Investigators at the University of Toronto performed a secondary cohort analysis of data prospectively collected for the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest trial from 1 April 2006 to 1 April 2007 by one site. The diagnostic test characteristics and predicted transportation rate were calculated for each rule. Of the 2415 patients with cardiac arrest of presumed cardiac etiology, the advanced life support rule recommended termination of resuscitation for 743 patients. No survivors were identified in this group. It had a specificity of 100% for recommending transport of potential survivors, a positive predictive value of 100% for death and a predicted transport rate of 69%. The basic life support rule recommended termination of resuscitation for 1302 patients, with no survivors. This rule had a specificity of 100%, a positive predictive value of 100% and a predicted transport rate of 46%. Implementing the basic life support rule as a universal termination of resuscitation clinical prediction rule would result in a lower overall transport rate without missing any potential survivors. The universal rule would recommend termination of resuscitation when there was no return of spontaneous circulation prior to transport, no shock was given and the arrest was not witnessed by Emergency Medical Services personnel. This rule may be useful for emergency medical services systems with mixed levels of providers responding to cardiac arrest patients.

Recurrent Ventricular Fibrillation During Advanced Life Support Care of Patients with Prehospital Cardiac Arrest: Koster RW, Walker RG, Chapman FW. Resuscitation 2008;78:252–7

This Dutch study documents the response of patients with ventricular fibrillation (VF) to defibrillation in the pre-hospital and emergency setting using 2000 Advanced Life Support (ALS) guidelines. There were 467 patients with ventricular fibrillation enrolled prospectively, and their response to three stacked shocks of 200 J, 200 J, and 360 J as part of ALS protocol was monitored for termination of VF and sustained organized rhythm. Ninety-two percent, 61%, and 83% of VF was terminated within the first three shocks, respectively.

Profile of Emergency Medical Dispatch Calls for Breathing Problems within the Medical Priority Dispatch System Protocol

A common chief complaint to emergency dispatch communication centers worldwide is "breathing problems". The chief complaint of breathing problems represents a wide spectrum of underlying diseases, patient conditions, and onset types. The current debate is on the potential ability of a dispatch protocol to safely and with high specificity, differentiate patients with minor or non-critical conditions from those conditions that pose risk to the patient and require advanced life support evaluation and care. This issue also has extended into the paramedic prehospital evaluation realm. The objective of this study was to describe the distribution of Medical Priority Dispatch System (MPDS) codes representing the spectrum of clinical descriptions within the breathing problems chief complaint and their associated outcomes, at the scene and during transport, as determined by [UK] paramedics. A retrospective, one-year study (September 2005 to August 2006) of a de-identified aggregate dataset from the London Ambulance Service (LAS) Trust was evaluated. A profile of the distribution of calls, incidents, patients, and outcomes (cardiac arrest [CA] and blue-in [BI] high acuity i.e., patients transported with lights and siren based on paramedic protocol) for the breathing problems chief complaint was evaluated. Odds ratios and 95% confidence intervals (CI) were used to quantify associations between the MPDS priority level's concurrent asthmatic conditions and outcomes. Two-sided Fisher's exact p-values were obtained to determine statistically significant associations, at a level of0.05. Sixteen percent (95,848/599,093) of all the patients were classified under the breathing problems chief complaint. Of these 95,848 patients, 367 (0.38%) were CA outcomes, and 7.82% (n = 7,493) were BI outcomes.The Cardiac Arrest Quotient (i.e., the number of CA cases as a percentage of the number of patients) for the ECHO priority level was 46 times higher than was that of non-ECHO priority levels: DELTA and CHARLIE (17.05% vs. 0.37%). Asthmatics were associated with CA outcome (OR(95%CI): 0.60(0.47,0.77), p <0.001), but not with BI outcome. The MPDS coding yielded a richer mix of severe outcomes in the higher priority levels.The Severe Respiratory Distress coding had the greatest number of patients and severe outcomes. Future studies that help refine the Severe Respiratory Distress code in the MPDS by more specific subgroups of patients would be beneficial.

Medication storage temperatures in primary response vehicles.

To the Editor : Paramedics practising pre-hospital emergency advanced life support care carry a range of parenteral medications including antiarrhythmics, analgesics, hypnotics and anticonvulsants. Unless otherwise indicated, medications should be stored at controlled room temperature (CRT) to limit accelerated thermal degradation caused by temperatures above CRT.

Recurrent ventricular fibrillation during advanced life support care of patients with prehospital cardiac arrest

The response of recurrent episodes of ventricular fibrillation (VF) to defibrillation shocks has not been systematically studied. We analyzed outcomes from countershocks delivered for VF during advanced life support (ALS) care of patients with out-of-hospital cardiac arrest. Cohort of patients with prehospital cardiac arrest presenting with VF, treated by ALS ambulance staff following ERC Guidelines 2000. Biphasic defibrillators provided shocks increasing from 200 to 360J. Recorded signals were analyzed to determine, for each shock, if VF was terminated and if a sustained organized rhythm was restored within 60s. In 465 of the 467 patients enrolled, the initial VF episode was terminated within three shocks: 92%, 61%, and 83% responded to 200J first, 200J second and 360J third shocks, respectively. VF recurred in 48% of patients within 2min of the first episode, and in 74% sometime during prehospital care. In the 175 patients experiencing five or more VF episodes, single shock VF termination dropped from the first to the fifth episode (90-80%, p<0.001) without change in transthoracic impedance, yet the proportion returning to organized rhythms increased (11-42%, p<0.0001). Repeated refibrillation is common in patients with VF cardiac arrest. The likelihood of countershocks to terminate VF declines for repeated episodes of VF, yet shocks that terminate these episodes result increasingly in a sustained organized rhythm.