Urban Emergency Medical Services System Research Articles

Why the Closest Ambulance Cannot be Dispatched in an Urban Emergency Medical Services System

Response time performance is related to increased survival for a relatively small group of patients with critical emergencies. Effectively utilizing current resources is a challenge for all emergency medical services (EMS) systems for reasons of cost-effectiveness and safety. The objective of this study was to identify opportunities for improving ambulance response-time performance in an urban EMS system using fixed deployment. This was a qualitative and quantitative case study which consisted of structured interviews with policy makers, managers, and workers in a fire department EMS division, as well as analysis of dispatch data and observation of dispatch operations. The current computer-aided dispatch (CAD) system does not identify the closest ambulance to the emergency, and therefore, dispatchers must guess which unit is closer when units are not within their stations or "first due" areas. There is no means to track how often dispatchers guess correctly or how often the closest ambulance actually is dispatched to the emergency. Temporal and geographic patterns were identified. Opportunities also were identified to improve response time performance through the use of dynamic deployment and peak-load staffing. The results suggest that there were opportunities for improving ambulance response times by implementing strategies such as peak-load staffing and dynamic deployment. However, the most important improvement would be the implementation of a policy to send the closest ambulance to the emergency. More research is needed to identify how prevalent the failure to send the closest ambulance is within EMS systems that use fixed-deployment response strategies and computer-aided dispatch systems that are incapable of tracking unit locations outside of their stations.

Epidemiology of Pediatric Transports andNon-Transports in an Urban Emergency Medical Services System

Objective. This study was done to describe an urban, Emergency Medical Service (EMS) system's experiences with pediatric patients andthe rate andcharacteristics of non-transports in this setting. Methods. A retrospective analysis of all pediatric patients responded to by the Detroit Fire Department Division of EMS between January 1, 2002 andAugust 30, 2002 was done. Results. There were 5,976 pediatric EMS cases. Children 10 years of age or older accounted for 49.4% of transports, 53.8% of all patients had medical illness, and38.8% of the patients belonged to the non-urgent category. A large percentage of patients were not transported (27.2%), most commonly secondary to parent/caregiver/patient refusals. The median number of minutes on-scene for refusals was longer than for transports (23.5 vs. 17.3, respectively)[difference = 6.2 minutes (95% CI: 5.6–6.9)]. The odds ratios (OR) for refusal was highest for assaults (2.09; 95% CI: 1.66–2.63), difficulty in breathing (1.38; 95% CI: 1.14–1.68), andmotor vehicle accidents (1.19; 95% CI: 1.04–1.37). Conclusions. In this system, the majority of pediatric patients are not severely ill, anda large number are not transported. Non-transports are more likely to be young adolescents, have been involved in assaults, andhave a longer on-scene time.

Thrombin-Antithrombin Appearance in Out-of-Hospital Cardiac Arrest

Objective. Intravascular thrombosis induced during out-of-hospital cardiac arrest (OOHCA) may contribute to the pathophysiology of cardiac arrest andcomplicate resuscitation. We characterized the prevalence of thrombogenesis during OOHCA by measuring plasma levels of thrombin-antithrombin complexes (TAT). Methods. An observational cohort study of medical OOHCA patients in an urban emergency medical services (EMS) system. Subjects were patients ≥18 years suffering medical OOHCA. Citrated blood samples were drawn in the prehospital setting either directly from venous blood or during the placement of a central venous catheter andfrozen (−70°C). The EMS physician documented age, gender, time intervals, return of spontaneous circulation (ROSC), therapies administered andtime of blood draw. TAT assays were performed by commercial ELISA. Results. Eighty-eight patients (58% male) aged 63.4 ± 15.9 years were enrolled in the study. Median [interquartile range IQR] TAT values in 80 samples (8 samples were grossly clotted andexcluded) were 159.2 [38, 2, 522, 8] andranged from 0.79 to 1,343.9. Patients transported to the hospital had lower TAT levels than those pronounced in the field (p = 0.014). Of four EMS-witnessed arrests, three had return of pulses with TAT values of 0.79, 6.8, and17.9. The fourth had a TAT over 525 after a long unsuccessful resuscitation. For subjects with TAT below 50 (n = 23), all but three were witnessed arrests or received bystander CPR. Conclusions. Except for a single case witnessed by EMS andimmediately defibrillated into a perfusing rhythm, all cases of OOHCA exhibited increased thrombotic state. Intravascular thrombosis may represent a global barrier to resuscitation andultimately, end-organ perfusion.

Impact of Citywide Blackout on an Urban Emergency Medical Services System

On 14 August 2003, New York City and a large portion of the northeastern United States experienced the largest blackout in the history of the country. An analysis of such a widespread disaster on emergency medical service (EMS) operations may assist in planning for and managing such disasters in the future. A retrospective review of all EMS activity within New York City's 9-1-1 emergency telephone system during the 29 hours during which all or parts of the city were without power (16:11 hours (h) on 14 August 2003 until 21:03 h on 15 August 2003) was performed. Control periods were established utilizing identical time periods during the five weeks preceding the blackout. Significant increases were identified in the overall EMS demand (7,844 incidents vs. 3,860 incidents; p < 0.001) as well as in 20 of the 62 call-types of the system, including cardiac arrests (119 vs. 76, p = 0.043). Significant decreases were found only among calls related to psychological emergencies (114 vs. 221; p = 0.006) and drug- or alcohol-related emergencies (78 vs. 146; p = 0.009). Though median response times increased by only 60 seconds, median call-processing times within the 9-1-1 emergency telephone system EMS dispatch center of the city increased from 1.1 to 5.5 minutes. The citywide blackout resulted in dramatic changes in the demands upon the EMS system of New York City, the types of patients for whom EMS providers were assigned to provide care, and the dispositions for those assignments. During this time of increased, system-wide demand, the use of cross-trained firefighter and first-responder engine companies resulted in improved response times to cardiac arrest patients. Finally, the ability of the EMS dispatch center to process the increased requests for EMS assistance proved to be the rate-limiting step in responding to these emergencies. These findings will prove useful in planning for future blackouts or any disaster that may broadly impact the infrastructure of a city.

Triage Accuracy at a Multiple Casualty Incident Disaster Drill: The Emergency Medical Service, Fire Department of New York City Experience

We sought to evaluate the accuracy and speed for the triage of multiple patients during a disaster drill by Emergency Medical Service (EMS) personnel. During a disaster drill (train collision with blast injury and chemical release), the accuracy and speed of triage of 130 patient-actors by the Fire Department of New York City (FDNY) EMS personnel was evaluated using the Simple Triage and Rapid Treatment (START) triage system. All EMS personnel had been previously trained in START, but refresher training was not administered before the drill. Overall triage accuracy was 78%. In patients that had additional changes in their status during the triage process (injects), 62% were retriaged appropriately. Because of security and decontamination procedures, triage at the triage/treatment area began 40 minutes after the drill commenced. It took 2 hours and 38 minutes to completely clear the scene of all patients. On average, the time from the start of triage to transport was 1 hour and 2 minutes. Despite the fact that triage is a skill practiced by every EMS system in the country on a daily basis, few studies regarding triage accuracy are available. Limited data suggest that the triage accuracy rates using different triage strategy algorithms are approximately 45% to 55%. During this drill, FDNY-EMS triage accuracy using the START system exceeded these expectations. This study provides insight as to the triage experience of a large urban EMS system operating at a disaster drill.

Use of an Automated, Load-Distributing Band Chest Compression Device for Out-of-Hospital Cardiac Arrest Resuscitation

Only 1% to 8% of adults with out-of-hospital cardiac arrest survive to hospital discharge. To compare resuscitation outcomes before and after an urban emergency medical services (EMS) system switched from manual cardiopulmonary resuscitation (CPR) to load-distributing band (LDB) CPR. A phased, observational cohort evaluation with intention-to-treat analysis of 783 adults with out-of-hospital, nontraumatic cardiac arrest. A total of 499 patients were included in the manual CPR phase (January 1, 2001, to March 31, 2003) and 284 patients in the LDB-CPR phase (December 20, 2003, to March 31, 2005); of these patients, the LDB device was applied in 210 patients. Urban EMS system change from manual CPR to LDB-CPR. Return of spontaneous circulation (ROSC), with secondary outcome measures of survival to hospital admission and hospital discharge, and neurological outcome at discharge. Patients in the manual CPR and LDB-CPR phases were comparable except for a faster response time interval (mean difference, 26 seconds) and more EMS-witnessed arrests (18.7% vs 12.6%) with LDB. Rates for ROSC and survival were increased with LDB-CPR compared with manual CPR (for ROSC, 34.5%; 95% confidence interval [CI], 29.2%-40.3% vs 20.2%; 95% CI, 16.9%-24.0%; adjusted odds ratio [OR], 1.94; 95% CI, 1.38-2.72; for survival to hospital admission, 20.9%; 95% CI, 16.6%-26.1% vs 11.1%; 95% CI, 8.6%-14.2%; adjusted OR, 1.88; 95% CI, 1.23-2.86; and for survival to hospital discharge, 9.7%; 95% CI, 6.7%-13.8% vs 2.9%; 95% CI, 1.7%-4.8%; adjusted OR, 2.27; 95% CI, 1.11-4.77). In secondary analysis of the 210 patients in whom the LDB device was applied, 38 patients (18.1%) survived to hospital admission (95% CI, 13.4%-23.9%) and 12 patients (5.7%) survived to hospital discharge (95% CI, 3.0%-9.3%). Among patients in the manual CPR and LDB-CPR groups who survived to hospital discharge, there was no significant difference between groups in Cerebral Performance Category (P = .36) or Overall Performance Category (P = .40). The number needed to treat for the adjusted outcome survival to discharge was 15 (95% CI, 9-33). Compared with resuscitation using manual CPR, a resuscitation strategy using LDB-CPR on EMS ambulances is associated with improved survival to hospital discharge in adults with out-of-hospital nontraumatic cardiac arrest.

Ventilatory Rates in an Urban Emergency Medical Services System

Ventilatory Rates in an Urban Emergency Medical Services System

Do Medications Affect Vital Signs in the Prehospital Treatment of Acute Decompensated Heart Failure?

Introduction. Prehospital treatment of patients with acute decompensated heart failure (ADHF) has been shown to decrease mortality andmorbidity. Vital sign changes have been proposed as clinical endpoints in the evaluation of prehospital treatment for this condition. Objective. To examine the effect of prehospital treatments on vital signs among patients with ADHF. Methods. Records of an urban emergency medical services system from September 1, 2002, through September 1, 2003, were queried for patients who had a paramedic impression of shortness of breath or respiratory distress andhad received nitroglycerin and/or furosemide. Demographics, initial andrepeat vital signs (blood pressure, heart rate, respiratory rate, andoxygen saturation), andmedications anddoses were collected. Results. Three hundred nineteen patients were included; the average age was 77 (±12) years and47% were male. Treatments administered to these patients included nitroglycerin, 296 (93%); furosemide, 194 (61%); albuterol, 189 (59%); aspirin, 57 (18%); morphine, 20 (6%); andprehospital intubation, 15 (5%). Patients were initially hypertensive [mean ± standard deviation of systolic blood pressure (SBP) was 167 ±37 mm Hg], tachycardic (heart rate 106 ± 24 beats/min), tachypneic (respiratory rate 33 ± 7 breaths/min), andhypoxic (pulse oximetry 88% ± 9.5%). After treatment, mean changes included decreases (95% confidence interval) in (SBP), −10.6 mm Hg (−14.1 to −7.1), heart rate, −2.3 beats/min (−4.0 to −0.7), andrespiratory rate, −3.0 (−3.6 to −2.3), andan increase in oxygen saturation, +8.2 (7.1 to 9.3). Changes in blood pressure andoxygen saturation after treatment correlated with initial values. There was no independent association of either nitroglycerin, furosemide, albuterol, or morphine with improvement in vital signs. Conclusion. Prehospital patients with ADHF are a heterogeneous group of patients with significant variability in vital signs. The change in systolic blood pressure or oxygen saturation after treatment depends greatly on the patient's starting point. There was no association of either nitroglycerin or other medications with the improvement in vital signs.

Predictors of Intubation Success andTherapeutic Value of Paramedic Airway Management in a Large, Urban EMS System

Background. Endotracheal intubation (ETI) is commonly used by paramedics for definitive airway management. The predictors of success andtherapeutic value with regard to oxygenation are not well studied. Objectives. 1) To explore the relationship between intubation success andperfusion status, Glasgow Coma Scale (GCS) score, andend-tidal carbon dioxide (EtCO2); 2) to describe the incidence of unrecognized esophageal intubations with use of continuous capnometry; and3) to document the incremental benefit of invasive versus noninvasive airway management techniques in correcting hypoxemia. Methods. This was a prospective, observational study conducted in a large urban emergency medical services system. Paramedics completed a telephone debriefing interview with quality assurance personnel following delivery of all patients in whom invasive airway management had been attempted. Continuous capnometry was used for confirmation of tube position in all patients. Descriptive statistics were used to document airway management performance, including first-attempt ETI success, overall ETI success, andCombitube insertion (CTI) success. In addition, the incidence of unrecognized esophageal intubation was recorded. The relationship between intubation success andperfusion status, GCS score, andinitial EtCO2 value was explored using logistic regression. Finally, recorded SpO2 values andthe incidence of hypoxemia (SpO2 < 90%) at baseline, following noninvasive airway maneuvers, andafter invasive airway management were compared for perfusing patients. Results. A total of 703 patients were enrolled over 12 months. First-attempt ETI success was 61%, andoverall ETI success was 81%; invasive airway management (ETI or CTI) was unsuccessful in 11% of patients. A single unrecognized esophageal intubation was observed (0.1%). A clear relationship between airway management success andperfusion status, GCS score, andinitial EtCO2 value was observed. Only EtCO2 demonstrated an independent association with ETI success after adjusting for the other variables. Significant improvements in mean SpO2 andthe incidence of hypoxemia over baseline were observed with both noninvasive andinvasive airway management techniques in 168 perfusing patients. Conclusions. A relationship between intubation success andperfusion status, GCS score, andinitial EtCO2 value was observed. Capnometry was effective in eliminating unrecognized esophageal intubations. Both noninvasive andinvasive airway management strategies were effective in increasing SpO2 values anddecreasing the incidence of hypoxemia, with additional benefit observed with invasive airway maneuvers in some patients.

Is prehospital blood glucose measurement necessary in suspected cerebrovascular accident patients?

The present study was completed to establish an epidemiologic database defining prehospital management of suspected cerebrovascular accidents (CVAs) with attention to blood glucose measurement, in the hope of developing recommendations for further treatment protocols. On review of 9495 paramedic run reports for the 24-month period from January 2001 through December 2002, from a low-volume urban emergency medical services system, 185 persons presented with CVA signs and/or symptoms. Data collected included patient chief complaint, neurologic examination, patient age, vital signs, ambulance field times, patient past medical history, and blood glucose measurement with resulting prehospital interventions, efficacy of interventions, and iatrogenic complications. Five persons (2.70%), all medication-controlled diabetics, were found to be hypoglycemic. After administration of intravenous dextrose 50% by rescue personnel, improvement in neurologic condition was noted in 100% of these cases. No sequelae as a result of such care occurred. No inappropriate use, point estimate ([0]/[5][0.00%-52.20%]), or unmet need, point estimate ([0]/[9495][0.00%-0.04%]), of care was noted. The data presented in this study suggest that given similar emergency medical service system characteristics, hypoglycemic patients presenting with neurologic deficits suggestive of CVAs constitute a rare event, associated with medical histories predictive of problems involving glucose homeostasis. Blood glucose measurement in persons presenting with CVA signs and/or symptoms is only necessary given the presence of history suspicious for hypoglycemia, or rescuer inability to obtain adequate patient information. Routine prehospital blood glucose measurement in patients with suspected CVA appears unnecessary.

Real-time paramedic compared with blinded physician identification of ST-segment elevation myocardial infarction: results of an observational study

The aim of the study were to determine if paramedics can accurately identify ST-segment elevation myocardial infarction (STEMI) on prehospital 12-lead (PHTL) electrocardiogram and to compare paramedic with blinded physician identification of STEMI. Paramedics identified definite STEMI, or possible acute myocardial infarction but not definite, and nondiagnostic. Two blinded readers (cardiologist and emergency physician) independently categorized each PHTL. A third reviewer assigned final diagnoses and determined whether the PHTL met STEMI criteria. One hundred sixty-six PHTL were acquired over an 8-month period. Fifteen were excluded from analysis. Sixty-two percent of the patients (94/151) were male, mean age was 61.1 years (±14.8 SD, range 20-92 years), and 81% had chest pain. Twenty-five patients (16.6%; 95% confidence interval [CI], 11%-23.5%) had confirmed STEMI and 16 (10.6%) had confirmed non-STEMI acute myocardial infarction. Paramedic sensitivity was 0.80 (95% CI, 0.64-0.96); specificity was 0.97 (95% CI, 0.94-1.00) with positive likelihood ratio of 25.2 and negative likelihood ratio of 0.21. Overall accuracy was similar for paramedic and physician reviewers (0.94, 0.93, 0.95). Highly trained paramedics in an urban emergency medical services system can identify patients with STEMI as accurately as blinded physician reviewers.

An Evaluation of Out-of-hospital Advanced Airway Management in an Urban Setting

To determine the success and complication rates associated with endotracheal intubation in an urban emergency medical services (EMS) system. This study evaluated consecutive airway interventions between March 2001 and May 2001 performed by paramedics from the Denver Health Paramedic Division in Denver, Colorado. Patients were identified and enrolled prospectively with the identification of all patients for whom intubation was attempted. A retrospective chart review of the emergency department (ED), intensive care unit, other hospital records, and the coroner's records was then conducted with the intent of identifying all complications related to attempted intubation, including the placement of each endotracheal tube. A total of 278 patients were included in this study. Of these, 154 (55%) had an initial nasal intubation attempt, and 124 (45%) had an initial oral intubation attempt. Of the 278 patients for whom an intubation was attempted, 234 (84%, 95% CI = 77% to 88%) were reported by paramedics to be successfully intubated. Of 114 nasal intubations reported as successful by paramedics, two (2%; 95% CI = 0.2% to 6%) were found to be misplaced. Of the 120 oral intubations reported as successful by paramedics, one (1%; 95% CI = 0.02% to 5%) was found to be misplaced. Of the 278 patients, 22 (8%; 95% CI = 5% to 12%) had complications; three (1%; 95% CI = 0.2% to 3%) endotracheal tubes were incorrectly positioned, two (0.7%; 95% CI = 0.08% to 3%) of which were undetected esophageal intubations and one (0.4%; 95% CI = 0 to 2%) of which was in the posterior pharynx. Reasonable success and complication rates of endotracheal intubation in the out-of-hospital setting can be achieved in a busy, urban EMS system without the assistance of medications.

Emergency medical services in Zimbabwe

Emergency medical services in Zimbabwe are of a very variable standard, and exist in many forms: • Reasonably well-developed urban emergency medical services systems mixed with very poorly resourced and under-developed rural services. • Very high patient workloads, with severely ill medical patients and a large proportion of major trauma and multiple-casualty situations (public safety is given a low priority, and public transport is poorly regulated). • Long emergency response times and patient transport distances. • Somewhat under resourced and under developed emergency departments, with large numbers of critically ill acute patients, as well as many non-emergency/chronic patients who have no other access to appropriate health care. This paper provides a description of the development of ambulance services and acute health care in Zimbabwe, and outline the current demands on the system. Particular reference is made to the City of Harare Ambulance Service, which is considered to be the most developed of the local authority services.

The three-phase model of cardiac arrest as applied to ventricular fibrillation in a large, urban emergency medical services system

Background: Cardiac arrest is responsible for significant morbidity and mortality, with consistently poor outcomes despite the rapid availability of prehospital personnel for defibrillation attempts in patients with ventricular fibrillation (VF). Recent evidence suggests a period of cardiopulmonary resuscitation (CPR) prior to defibrillation attempts may improve outcomes in patients with moderate time since collapse (4–10 min). Objectives: To determine cardiac arrest outcomes in our community and explore the relationship between time since collapse, performance of bystander CPR, and survival. Methods: Non-traumatic cardiac arrest data were collected prospectively over an 18-month period. Patients were excluded for: age <18 years, a “Do Not Attempt Resuscitation” (DNAR) directive, determination of a non-cardiac etiology for arrest, and an initially recorded rhythm other than VF. Patients were stratified by time since collapse (<4, 4–10, >10 min, and unknown) and compared with regard to survival and neurological outcome. In addition, patients with and without bystander CPR were compared with regard to survival. Results: A total of 1141 adult non-traumatic cardiac arrest victims were identified over the 18-month study period. This included 272 patients with VF as the initially recorded rhythm. Of these, 185 had a suspected cardiac etiology for the arrest; survival to hospital discharge was 15% in this group, with 82% of these having a good outcome or only moderate disability. Survival was highest among patients with time since collapse of less than 4 min and decreased with increasing time since collapse. There were no survivors among patients with time since collapse greater than 10 min. Among patients with time since collapse of 4 min or longer, survival was significantly higher with the performance of bystander CPR; there was no survival advantage to bystander CPR among patients with time since collapse less than 4 min. Conclusions: The performance of bystander CPR prior to defibrillation by EMS personnel is associated with improved survival among patients with time since collapse longer than 4 min but not less than 4 min. These data are consistent with the three-phase model of cardiac arrest.

The Effect of an 18-Hour Electrical Power Outage on an Urban Emergency Medical Services System

Objectives. To describe the experience of an urban, commercial ambulance provider during the multistate August 2003 electrical power outage (EPO) andto identify how such an event can affect an emergency medical services (EMS) system. Methods. Data were abstracted from all dispatch andprehospital medical records generated during the 18-hour EPO. An hour-by-hour comparison was made between the median number of hourly EMS dispatches during the month of August 2003 andthe total number of hourly EMS dispatches during the EPO. Presenting complaints were categorized, andall calls related to the EPO were identified. Results. During the first ten hours of the EPO, hourly call volume increased an average of 250% (range 50%–500%) as compared with all of August 2003. The greatest increase in call volume occurred during the first seven hours of the EPO. During the EPO, 16% (n = 13) of patients presented with a heat-related complaint precipitated by the failure of air conditioning. In the same period, 37% (n = 31) of patients presented with a respiratory-related complaint, 52% (n = 16) of which were precipitated by the failure of home respiratory equipment such as ventilators, nebulizers, andoxygen concentrators. During the EPO, the average time spent on scene with patients increased 63%, from 11 to 18 minutes, when compared with the time spent 16 hours immediately prior and14 hours immediately after the EPO. Average response andtransport times did not change. Conclusion. Loss of power can cause a dramatic but short-term increase in call volume andlead to a disaster-like situation. EMS resources may be conserved by proactively assisting patients with home medical devices before they develop emergent conditions. Such a patient population might benefit, for example, from home deliveries of portable oxygen tanks or from the creation of temporary facilities that provide a climate-controlled environment andelectrically powered medical devices. Key words: power outage; acute respiratory; emergency medical services; disaster preparedness; environmental emergency.

Treatment of Suspected Cardiac Ischemia with Aspirin by Paramedics in an Urban Emergency Medical Services System

Background. Aspirin (ASA) has unquestioned benefit to patients with cardiac ischemia. Previous studies indicate health care providers may not adequately treat patients experiencing cardiac ischemia with ASA. Objective. To determine the rate of ASA use for patients being treated for chest pain suggestive of cardiac ischemia in the prehospital setting. Methods. This was a retrospective study of paramedic encounters identified through billing records for all patients receiving the combination of an intravenous catheter, supplemental oxygen, andcardiac monitoring from November 2001 to January 2002. Prehospital medical records were reviewed in order to determine the proportion of patients with suspected cardiac ischemia who received ASA. The setting was a single prehospital emergency medical services system serving an urban population. Results. A total of 2,457 paramedic encounters were reviewed over a three-month period. Two hundred thirty-two patients were assessed as having cardiac ischemia, of whom 169 (73%) had no absolute or relative contraindication to ASA. Of the 169 patients, only 92 (54%) received ASA. Of the 99 patients, who received nitroglycerin for presumed cardiac ischemia andhad no contraindication to receiving ASA, only 78 (79%) received ASA. Of the 453 patients complaining of nontraumatic chest pain andwithout a contraindication, 157 (35%) received ASA. Conclusions. Paramedics do not use ASA optimally andmay choose therapies with less proven benefit.

Impact of Liberalization of Protocols for the Use of Morphine Sulfate in an Urban Emergency Medical Services System

Objective. To investigate the impact of liberalization of paramedic management protocols for the use of morphine sulfate (MS). Methods. A retrospective database analysis tallied andcategorized MS use into seven conditions during two intervals—six months before (control) andsix months after (study) the protocol change. Results. In the control interval, 760 of 34,020 (2.2%) patients received MS. In the study interval, 999 of 30,320 (3.3%) received the drug, a 50% relative increase in MS use. MS use dramatically increased in two assessment categories: other painful medical conditions (19.0% vs. 2.8% of transports, relative risk [RR] 6.8, 95% confidence interval [CI] 5.2–8.9) andnontraumatic abdominal pain (9.2% vs. 1.9% of transports, RR 4.8, 95% CI 3.3–6.9). Conclusion. Liberalization of pain management protocols resulted in an appreciable increase in the use of MS only in medical categories, predominantly abdominal pain, with no apparent safety or misuse issues.

Presentation andSurvival of Prehospital Apparent Sudden Infant Death Syndrome

Background. Prehospital providers are often involved in the resuscitation of apparent sudden infant death syndrome (SIDS) victims; however, data are few on the presentation andoutcome of these patients.Objectives. To describe the presentation anddetermine the survival rate of infants who have an unwitnessed, prehospital arrest consistent with SIDS (apparent SIDS), andto compare the presentation of infants with a final diagnosis of SIDS with those who presented as apparent SIDS but had a different final diagnosis.Methods. This was a secondary analysis of data from a controlled trial whose methodology has been previously described. The setting was two large, urban emergency medical services (EMS) systems of Los Angeles andOrange Counties, California. The population included 113 apparent SIDS victims from the original interventional study who had a prehospital, unwitnessed arrest consistent with SIDS, defined by the scenario of an infant aged ≤12 months being placed to sleep andlater found in full arrest (pulseless andapneic). Data collected included ethnicity, gender, arrest etiology, signs of death (lividity, rigor mortis), prehospital interventions, return of spontaneous circulation (ROSC), arrest rhythm, code 3 transport (lights andsirens), andsurvival to hospital discharge.Results. One hundred ten of 113 apparent SIDS patients had survival data; 0 of 110 (95% CI 0% to 3.3%) survived, although ROSC was achieved in 5%; for three patients data on survival were missing. Arrest rhythms were determined in 94% of the subjects: asystole 87%, pulseless electrical activity (PEA) 8%, andventricular fibrillation 4%. Only 50 of 113 (44%) of the EMS records documented code 3 transport; the remainder of the records were ambiguous. SIDS was the final coroner's diagnosis for 79 of 113 (70%) of the cases. Other causes of death in these apparent SIDS victims included respiratory causes (12%), asphyxiation (3%), abuse (2%), congenital heart disease (2%), sepsis (2%), other (4%), andunknown (5%). Apparent SIDS victims with a final diagnosis of SIDS were more likely to show signs of death (27/79, 34% vs. 5/34, 15%, p = 0.035) andwere less likely to have a rhythm of PEA (4/77, 5% vs. 5/31, 16%, p = 0.08), although the latter result was not statistically significant.Conclusions. Apparent SIDS victims have a dismal prognosis; all infants presenting with apparent SIDS died, even the 30% whose final diagnosis was not SIDS. Given that there were no survivors, new prehospital policies are needed governing the use of lights andsirens, resuscitation decisions including termination of resuscitation, provision of grief support to families, andincident stress debriefing for prehospital personnel.

P.6.011 Modulation of cholinergic brain activity and its reflection in special EEG frequency ranges from various brain areas in the freely moving rat

Objective. Combative patients pose a threat to themselves and prehospital personnel, and are at risk for sudden death. Droperidol is an antipsychotic and sedative agent that might be effectively utilized by paramedics to assist in the management of uncontrollably violent patients. Methods. A prospective observational study of patients requiring sedation was conducted in an urban third-service emergency medical services system (55,000 calls per year). Patients were scored by paramedics on a five-point agitation scale with 5 being extremely combative (continuous, vigorous fighting against restraints) and 1 being somnolent (sleeping or sleepy). Eligible (score 4-5) patients received 5 mg of intramuscular droperidol on direct physician order. Data including vital signs and agitation scores were recorded at 5-minute intervals until hospital arrival. Adverse effects were also recorded. Results. Fifty-three patients received droperidol (51 patients received 5 mg; two received 2.5 mg) during the study period. The average predrug agitation score was 4.7 (±0.1 SD). The average 5-minute postdrug score was 3.9 (±0.1 SD, 95% CI 3.7-4.1). The average 10-minute postdrug score was 3.3 (±0.1 SD, 95% CI 3.1-3.6). The average hospital arrival score was 2.8 (±0.1 SD, 95% CI 2.5-3.1). One patient became obtunded and required supplemental oxygen; no other patient experienced an adverse event after receiving droperidol. Sedation was ineffective in seven patients, three of whom had head injuries, and one of whom received 2.5 mg of droperidol per physician order. Paramedics sustained no needlestick exposures. Conclusion. Intramuscular droperidol contributed to effective and rapid prehospital sedation in this observational series of 53 combative patients. PREHOSPITAL EMERGENCY CARE 2001;5:391-394

An opportunity for reform: A comprehensive evaluation of non-transport patterns in an urban emergency medical services setting

Study objectives: Patients who summon 911 paramedics and are subsequently not transported represent a high-risk patient group for an emergency medical services (EMS) system. In an effort to understand the magnitude and construct of our EMS system's nontransport population, we undertake a comprehensive review of every nontransport in our urban EMS system during 1 month's time. Our EMS system serves a population of 1.4 million and has a dual (private and fire-based) paramedic response. Methods: During January 2002, every 911 call in which paramedics made patient contact and that did not result in a patient transport was reviewed. A detailed data collection form and predetermined data dictionary were used for chart abstraction. EMS agencies and providers were blinded to the study details and purpose. Runs that did not result in a patient contact and all patients who were declared dead on arrival were excluded from the study. Our intent was to examine 4 important areas: (1) to quantify the total number and type of high-risk patients who were encountered; (2) to assess the quality of the EMS evaluation and documentation; (3) to determine whether decisionmaking capacity was assessed or documented by paramedics; and (4) to determine the amount of effort that was put forth by the paramedics to persuade the patients to go to the hospital. All data were abstracted and entered into a database (MS Access) by 2 of the emergency physician authors, and statistical analysis was performed using MS Excel. Results: During the 31-day study period, there were 755 nontransport charts submitted for review; of these, 732 had complete information and constitute the analysis cohort. The average patient age was 40.3±0.84 years (range 6 months to 98 years). Two hundred fifty-six (35%) patients represented high-risk chief complaints. Of the 12 high-risk chief complaints that were sought, 6 (shortness of breath: n=66; syncope: n=45; chest pain: n=44; altered mental status: n=29; abdominal pain: n=26; and traumatic neck pain: n=23) accounted for 91% of the high-risk chief complaint cases. One hundred thirty-one (19%) of the patients who were not transported had abnormal vital signs, and only 8% of these had vital signs repeated. One hundred seventy-two (24%) represented patients who were difficult, if not impossible, to establish decisionmaking capacity because of being a minor (n=111), being intoxicated (n=45), or because of communication barriers (n=16). And finally, 142 (19%) had advanced care provided (12-lead ECG, intravenous access, parenteral medications) and were subsequently released. In terms of documentation, an adequate medical history was recorded and physical examination performed in 82% (602/732) and 68% (495/732) of the cases, respectively. Decisionmaking capacity was documented in 41% (301/732) of the cases, and a complete set of vital signs (blood pressure, pulse rate, respiratory rate, for all and Spo 2 for patients with shortness of breath and chest pain) were taken in 48% (348/732) of the cases. The most consistently documented aspect of the entire against medical advice (AMA) process was completion of the AMA Form. In 655 (89.5%) of the cases, paramedics had a signed form before release. Paramedics documented that they had encouraged transport in 258 (35%) of the cases, explained the risks of not being transported in 112 (15%), enlisted the help of others in 173 (24%), contacted medical control in only 8 (1%), and instructed patients to re-call 911 if their condition worsened or if they changed their mind in 140 (19%) of the cases. This study's limitations include its being performed in a single system and that it represents only a single time interval. The high-risk chief complaints need prospective validation and comparison to outcomes to truly determine amount of risk. Conclusion: In our EMS system, there is an opportunity to improve the entire process of nontransport documentation and decisionmaking by our paramedics. Because just over one third of nontransported patients are high-risk cases, and the vast majority of these cases are accounted for by 6 chief complaints, our results may have important educational and performance improvement implications for similar EMS systems.