Urban EMS Research Articles

Management of Prehospital Seizure Patients by Paramedics

Background. Seizure patients are frequently encountered in the prehospital environment andhave the potential to need advanced interventions, though the utility of advanced life support (ALS) interventions in many of these patients has not been proven. Objective. Our goals were to assess the management of prehospital seizure patients by paramedics in an urban EMS system with an existing ALS-based prehospital seizure protocol andto assess characteristics andshort-term outcomes that may aid in addressing the utility of specific ALS interventions. Methods. This was a retrospective study of 97 EMS cases with the chief complaint of seizure. Prehospital records were reviewed for patient andevent characteristics, including past seizure history, seizure timing, level of consciousness, on-scene andtransport times, andEMS interventions. Emergency department (ED) records were reviewed for recurrence of seizure activity, ED evaluation, anddisposition. Data were analyzed using descriptive statistics andStudent t-test. Results. Of 87 patients meeting the protocol inclusion criteria for all ALS interventions, 11 (12.6%) received cardiac monitoring, 55 (63.2%) had intravenous (IV) access attempted, and56 (64.4%) had blood glucose determination. Average on-scene time was 5.9 minutes longer if IV access was attempted (p = 0.001), though transport times were not significantly different (11.6 versus 11.3 minutes, respectively; p = 0.851). Additional seizure activity occurred in the prehospital and/or ED settings in 28 patients (28.9% of all cases), including 17 in the prehospital setting and15 in the ED. Diazepam was administered by EMS for half of the eight (8.2%) patients who had seizures lasting more than 1 minute, while the remainder had seizures that were focal or spontaneously resolved. Conclusion. This study showed a lower-than-anticipated level of compliance with an ALS-based prehospital seizure protocol, though patient-specific care appeared appropriate. Prehospital seizure patients have the potential for seizure recurrence andmay benefit from focused ALS interventions, but their heterogeneity makes uniform protocols difficult to develop andfollow.

Biphasic Defibrillation Does not Improve Outcomes Compared to Monophasic Defibrillation in Out-of-Hospital Cardiac Arrest

Study Objective. To compare the outcomes of out-of hospital cardiac arrest (OHCA) victims treated with monophasic truncated exponential (MTE) versus biphasic truncated exponential (BTE) defibrillation in an urban EMS system. Methods. We conducted a retrospective review of electronic prehospital andhospital records for victims of OHCA between August 2000 andJuly 2004, including two years before andafter implementation of biphasic defibrillators by the Fresno County EMS agency. Main outcome measures included: return of spontaneous circulation (ROSC), number of defibrillations required for ROSC, survival to hospital discharge, anddischarge to home versus an extended care facility. Results. There were 485 cases of cardiac arrest included. Baseline characteristics between the monophasic andbiphasic groups were similar. ROSC was achieved in 77 (30.6%, 95% CI 25.2–36.5%) of 252 patients in the monophasic group, andin 70 (30.0% 95% CI 24.5–36.2%) of 233 in the biphasic group (p =. 92). Survival to hospital discharge was 12.3% (95% CI 8.8–17%) for monophasic and10.3% (95% CI 7.0–14.9%) for biphasic (p =. 57). Discharge to home was accomplished in 20 (7.9%, 95% CI 5.1–12.0%) of the monophasic, andin 15 (6.4%, 95% CI 3.9–10.4%) of the biphasic group (p =. 60). More defibrillations were required to achieve ROSC (3.5 vs. 2.6, p =. 015) in the monophasic group. Conclusions. We found no difference in ROSC or survival to hospital discharge between MTE andBTE defibrillation in the treatment of OHCA, although fewer defibrillations were required to achieve ROSC in those treated with biphasic defibrillation.

Paramedic Use of Needle Thoracostomy in the Prehospital Environment

Objective. The use of prehospital needle thoracostomy (NT) is controversial as it is not without risk. Issues such as inappropriate patient selection, misplacement causing iatrogenic injury, treatment failures in obese patients, anddelaying definitive tube thoracostomy in the emergency department contribute to this controversy. The purpose of this study is to evaluate a cohort of patients undergoing NT by paramedics for tension pneumothorax andreview the indications for use, complications, andemergency department outcomes of NT. Methods. We conducted a retrospective review of patients undergoing NT in the prehospital setting andtransported directly to a Level 1 trauma center over a one-year period. Patients were transported by a single ground transport agency staffed by paramedics. All paramedics were trained to follow uniform protocols for treatment procedures. Variables included indications for NT, patient demographics, prehospital vital signs, injury mechanism, chest X-ray, andEmergency Department outcomes. Results. Paramedics responded to 20,330 advanced life support calls, and39 (0.2%) patients had a NT placed for treatment of tension pneumothorax. Twenty-two (56.4%) patients were in circulatory arrest, with 12 suffering traumatic arrest and10 patients in nontraumatic PEA arrest. The remaining 17 (43.6%) patients were treated for nonarrest causes. Conclusions. The use of NT appears to be a safe procedure when preformed by paramedics in an urban EMS system. Prehospital NT resulted in four cases of unexpected survival.

Estimates of Cost-Effectiveness of Prehospital Continuous Positive Airway Pressure in the Management of Acute Pulmonary Edema

Objective. To estimate the cost-effectiveness of continuous positive airway pressure (CPAP) in managing prehospital acute pulmonary edema in an urban EMS system. Methods. Using estimates from published reports on prehospital andemergency department CPAP, a cost-effectiveness model of implementing CPAP in a typical urban EMS system was derived from the societal perspective as well as the perspective of the implementing EMS system. To assess the robustness of the model, a series of univariate andmultivariate sensitivity analyses was performed on the input variables. Results. The cost of consumables, equipment, andtraining yielded a total cost of $89 per CPAP application. The theoretical system would be expected to use CPAP 4 times per 1000 EMS patients andis expected to save 0.75 additional lives per 1000 EMS patients at a cost of $490 per life saved. CPAP is also expected to result in approximately one less intubation per 6 CPAP applications andreduce hospitalization costs by $4075 per year for each CPAP application. Through sensitivity analyses the model was verified to be robust across a wide range of input variable assumptions. Conclusion. Previous studies have demonstrated the clinical effectiveness of CPAP in the management of acute pulmonary edema. Through a theoretical analysis which modeled the costs andclinical benefits of implementing CPAP in an urban EMS system, prehospital CPAP appears to be a cost-effective treatment.

Abstract 2003: More Chest Compressions and Fewer Shocks Are Given During Out-of-Hospital Cardiac Arrest Resuscitation With the 2005 AHA Guidelines

Introduction Long pauses without chest compressions (CC) have been identified in CPR provided by EMS professionals for out-of-hospital cardiac arrest (OOHCA). The 2005 AHA ECC CPR guidelines emphasize CC. The 2005 AHA Basic Life Support (BLS) for Healthcare Professionals (HCP) course introduced a training method with more CPR skills practice during the DVD based course. The purpose of this before/after study was to determine whether CC rates increased after introduction of the 2005 course. Methods This urban EMS system has 400 cardiac etiology OOHCA events annually. A convenience sample of 49 continuous electronic ECG recordings of VF patients was analyzed with the impedance channel of the LIFEPAK 12 (Physio-Control, Redmond WA) and proprietary software. A trained researcher verified the automated analysis. Each CC during the resuscitation attempt and pauses in CC before and after the first defibrillation shock were noted. The time of return of spontaneous circulation (ROSC) was determined by medical record review and onset of regular electrical activity without CC. Medical records were reviewed for outcome to hospital discharge. The EMS patient care protocol for VF was changed on July 1, 2006 to comply with the 2005 AHA ECC guidelines. Cases were grouped by the OOHCA date: 9/2004 to 12/31/2006 (pre) and 7/1/2006 to 4/21/2007 (post). EMS personnel began taking the 2005 BLS for HCP course during spring 2006. Monthly courses over 3 years will recertify 1500 personnel. Results 29 cases were analyzed from the pre group and 20 from the post group. Compressions per minute increased from a mean (±SD) of 47 ± 16 pre to 75 ± 33 post (P < 0.01). The mean count of shocks given per victim decreased from 4.5 ± 4.0 pre to 2.8 ± 1.8 post (P < 0.04). The CC pause before the first shock was unchanged (23.6 ± 18.4 seconds to 22.1 ± 17.9). but the CC pause following that shock decreased significantly from 48.7 ± 63.2 to 11.8 ± 22.5 (p=0.008). Rates of ROSC (55% pre, 50% post) and survival to discharge (15% pre, 13% post) were similar. Conclusion Following introduction of the 2005 BLS for HCP course and the EMS protocol change, the quality of CPR delivered to victims of OOHCA improved significantly compared with pre-2006 CPR. The sample size was too small to detect differences in survival rates.

Derivation and evaluation of a termination of resuscitation clinical prediction rule for advanced life support providers

The primary aim was to derive a new termination of resuscitation (TOR) clinical prediction rule for advanced life support paramedics (ALS) and to measure both its pronouncement rate and diagnostic test characteristics. Secondary aims included measuring the test characteristics of a previously derived and published basic life support termination of resuscitation (BLS TOR) clinical prediction rule [Morrison LJ, Visentin LM, Kiss A, et al. Validation of a rule for termination of resuscitation in out-of-hospital cardiac arrest. N Engl J Med 2006;355(5):478-87] on the same cohort of patients for comparison purposes. Secondary data analysis of adult cardiac arrests treated by ALS in rural and urban EMS systems participating in the OPALS study (data extracted from Phase III). A previous study for a basic life support termination of resuscitation (BLS TOR) clinical prediction rule proposed Termination of Resuscitation if the patient had no return of spontaneous circulation (ROSC) before transport; no shock administered; EMS personnel did not witness the arrest [Morrison LJ, Visentin LM, Kiss A, et al. Validation of a rule for termination of resuscitation in out-of-hospital cardiac arrest. N Engl J Med 2006;355(5):478-87]. Multivariable logistic regression was used to examine the relationship between these variables, additional Utstein variables, and the primary outcome of survival to hospital discharge. Diagnostic test characteristics were measured for both the ALS TOR and BLS TOR models on this derivation cohort. Four thousand six hundred and seventy-three cardiac arrest patients were included; 3098 (66%) were male, mean (S.D.) age 69 (15); 239 (5.1%; 95% CI 4.5-5.8) survived to hospital discharge; 3841 patients had no ROSC (82%) and of these only three survived (0.08%; 95% CI 0.02, 0.23). The final ALS TOR model associated with survival, included: ROSC (OR 260.9; 95% CI 96.3, 706.7), bystander witnessed (OR 2.0; 95% CI 1.3, 3.1), bystander CPR (OR 2.8; 95% CI 1.9, 4.1), EMS witnessed (OR 12.3; 95% CI 7.1, 21.3) and shock prior to transport (OR 6.4; 95% CI 4.1, 10.1). A new ALS TOR clinical prediction rule based on these variables was 100% sensitive (95% CI 99.9-100) for survival and had 100% negative predictive value (95% CI 99.9-100) for death. Under the ALS TOR clinical prediction rule, 30% of patients would be pronounced in the field. The BLS TOR clinical prediction rule, was 100% sensitive (95% CI 99.9, 100), had 100% negative predictive value (95% CI 99.9-100) and the field pronouncement rate was 48%. Cardiac arrest patients may be considered for prehospital ALS TOR when there is no ROSC prior to transport, no shock delivered, no bystander CPR and the arrest was not witnessed by bystanders or EMS. A single EMS termination clinical prediction rule for all levels of providers would be optimal for EMS systems to implement. Prospective evaluation of the ALS TOR clinical prediction rule in the hands of ALS providers will be required before implementation.

The feasibility of a regional cardiac arrest receiving system

Patients suffering out-of-hospital cardiac arrest (OOHCA) are generally transported to the closest ED, presumably to expedite a hospital level of care and improve the chances of return for spontaneous circulation (ROSC) or provide post-resuscitative care for patients with prehospital ROSC. As hospital-based therapies for survivors of OOHCA are identified, such as hypothermia and emergency primary coronary interventions (PCI), certain hospitals may be designated as cardiac arrest receiving facilities. The safety of bypassing non-designated facilities with such a regional system is not known. To explore the potential ED contribution in OOHCA victims without prehospital ROSC and document the relationship between transport time and outcome in patients with prehospital ROSC. This was a prospective, observational study conducted in a large, urban EMS system over an 18-month period. Data were collected using the Utstein template for OOHCA. The incidence of prehospital ROSC was calculated for patients who were declared dead on scene, transported but died in the ED, died in the hospital, and survived to hospital discharge. The relationship between transport time and survival was also explored for patients with prehospital ROSC. A total of 1141 cardiac arrest patients were enrolled over the 18-month period. A strong association between prehospital ROSC and final disposition was observed (chi-square test for trend p<0.001). Only two patients who survived to hospital discharge did not have prehospital ROSC. Mean transport times were not significantly different for patients with prehospital ROSC who were declared dead in the ED (8.3min), died following hospital admission (7.8min), and survived to hospital discharge (8.5min). Outcomes in patients with prehospital ROSC who had shorter (7min or less) versus longer transport times were similar, and receiver-operator curve analysis indicated no predictive ability of transport time with regard to survival to hospital admission (area under the curve=0.52). In this primarily urban EMS system, the vast majority of survivors from OOHCA are resuscitated in the field. A relationship between transport time and survival to hospital admission or discharge was not observed. This supports the feasibility of developing a regional cardiac arrest system with designated receiving facilities.

Dispatcher-assisted CPR improves survival from non-traumatic out-of hospital cardiac arrest

Purpose of the study: Cardiopulmonary resuscitation (CPR) can improve survival and/or neurological outcome from out-of-hospital cardiac arrest (CA). Dispatcher-assisted CPR (D-CPR) uses dispatchers to assist the caller to perform CPR, and enhance survival. We aimed to assess the effect of D-CPR on survival and neurological outcome after CA in an urban EMS system. Material and methods: All non-traumatic out-of-hospital CA cases in Prague, Czech republic in 2004–2005 were analysed retrospectively and all cases, where the victim was not reported by the caller as “being conscious” in the time of first emergency call were included to the study.

The out-of-hospital use of a domestic violence screen for assessing patient risk

Objectives. To determine the following: 1) whether a Domestic Violence Scene Assessment Screen (DVSAS) is accurate at predicting domestic violence (DV) when compared with results on the validated Abuse Assessment Screen (AAS), and 2) whether EMTs can perform accurately on a DVSAS after they have finished a transport so as not to interfere with routine care. Methods. All patients transported by ambulance from domestic environments (i.e., home) by an urban EMS system were included in the study. A ten-question screen was developed to assess whether a domestic environment had a high risk of having DV (DVSAS). A positive answer to any of the questions was considered to be a positive result on the screen. A trained observer with no clinical duties rode on the ambulance for randomized shifts during a two-month period. The observer completed the DVSAS while at the scene, then the patient, if able, completed the AAS. After finishing the transport, the EMT completed the DVSAS based on his or her memory of the scene. Results of the observer DVSAS were compared with the results of the EMT DVSAS and with the AAS. Results. A total of 43 transports from domestic scenes were included in the study. The observer DVSAS alone was positive in five cases (12%), the EMT DVSAS alone was positive in five cases (12%), and both were positive in seven cases (17%). Agreement between the EMT and the observer yielded a kappa of 0.56 adjusted for chance. Of 15 (42%) patients able to complete the AAS, one (7%) was positive on the AAS alone, four (27%) were positive on the observer DVSAS alone, and three (29%) were positive on both. The observer DVSAS agreed with the AAS results in ten of 15 (66%) of cases. When compared with the AAS, the observer DVSAS had a sensitivity of 75%, specificity of 55%, positive predictive value of 38%, and negative predictive value of 86%. Conclusion. Emergency medical technicians can complete the DVSAS at the end of a transport with good agreement with results obtained by an independent observer at the scene. The DVSAS is able to reflect the results of the AAS with moderate to good agreement. PREHOSPITAL EMERGENCY CARE 2000;4:24-27

Do warning lights and sirens reduce ambulance response times?

Objective. To determine the time saving associated with lights and siren (L&S) use during emergency response in an urban EMS system. Methods. This prospective study evaluated ambulance response times from the location at time of dispatch to the scene of an emergency in an urban area. A control group of responses using L&S was compared with an experimental group that did not use L&S. An observer was assigned to ride along with ambulance crews and record actual times for all L&S responses. At a later date, an observer and an off-duty paramedic in an identical ambulance retraced the route—at the same time of day on the same day of the week—without using L&S and recorded the travel time. Response times for the two groups were compared using paired t-test. Results. The 32 responses with L&S averaged 105.8 seconds (1 minute, 46 seconds) faster than those without (95% confidence interval: 60.2 to 151.5 seconds, p = 0.0001). The time difference ranged from 425 seconds (7 minutes, 5 seconds) faster with L&S to 210 seconds (3 minutes, 30 seconds) slower with L&S. Conclusion. In this urban EMS system, L&S reduce ambulance response times by an average of 1 minute, 46 seconds. Although statistically significant, this time saving is likely to be clinically relevant in only a very few cases. A large-scale multicenter L&S trial may help address this issue on a national level. PREHOSPITAL EMERGENCY CARE 2000;4:70-74

Prospective use of a clinical decision rule to identify pulmonary embolism as likely cause of outpatient cardiac arrest

A clinical decision rule (CDR) derived retrospectively found that 57% of outpatients aged 65 years or less, with witnessed arrest + PEA had pulmonary embolism (PE) as cause of cardiac arrest. These retrospectively studied patients also had significant frequency of pre-arrest respiratory distress, altered mental status, and shock. Objectives: (1) To test prospectively the feasibility and diagnostic accuracy of this CDR. (2) To test if the pre-arrest clinical triad of respiratory distress, altered mental status and shock predicts the presence of PE. All EMS personnel ( N = 204) in an urban EMS system and Emergency Department physicians ( N = 143) at 7 hospitals were included in the CDR and data collection. Inclusion criteria: age 18–70, non-trauma, witnessed arrest, PEA as the first and primary rhythm. Exclusion: defibrillation before or more often than once after PEA. Criterion standards: autopsy or predefined cardiopulmonary imaging for PE. Over 21 months, 44 subjects were enrolled. Thirty-three subjects had a criterion standard ( N = 20 autopsy, 13—other criteria). 18/33 (54%; 95% CI 36–72%) had PE. Of the PE arrests, 88% were witnessed by EMS ( N = 8) or ED physicians ( N = 8), compared with 47% in the non-PE group ( N = 3 EMS and N = 4 ED). Of the PE arrests, 83% had at least two of the three components of the triad versus 33% of the non-PE group (95% CI for difference 20–79). Mortality was 100% in the PE group. Analysis of the EMS cardiac arrest registry indicated that 65% of all patients served by the EMS system, age ≤70 recorded as having pre-hospital PEA arrest were enrolled during the study period. Conclusions: We implemented successfully a CDR in a large, urban prehospital system to detect PE rapidly as most likely cause of cardiac arrest.

Impact of a bimodal SARS outbreak on paramedic resources of a large urban EMS system

Impact of a bimodal SARS outbreak on paramedic resources of a large urban EMS system

Hand sanitization rates in an urban EMS system

Hand sanitization rates in an urban EMS system

The perspective of paramedics about on-scene termination of resuscitation efforts for pediatric patients

The purpose of this study was to assess the attitude of paramedics to on-scene termination of cardiopulmonary resuscitation (T-CPR) efforts in children prior to developing a pediatric T-CPR policy. A 26-item anonymous survey was conducted of all of the active paramedics in a large urban EMS system where T-CPR had been practiced routinely for adults. Questions addressed paramedic demographics, training level, experience with adult and pediatric advanced cardiac life support (ACLS), experience with T-CPR in adults, T-CPR case scenarios, and T-CPR in children. All 201 paramedics in the system (mean age=34.2 years; mean years as paramedic = 8.5 ) completed all relevant items of the survey (100% compliance). Two-thirds had provided ACLS for cardiac arrest to >50 adults (93% >10 adults) and more than one-third had performed ACLS on >20 children (72% >5 children). In addition, 90% had participated in T-CPR for adults. The majority of paramedics reported at least occasional (pre-defined) difficulty with adult T-CPR including family confrontation, 43%; personal discomfort, 13%; disagreement with physician decision to continue efforts, 11%; and fear of liability, 10%. Paramedic self ratings of comfort with terminating CPR on a scale from 1 to 10 (1: very comfortable; 10: uncomfortable) for adults and children were 1 and 9, respectively (P<0.001). In addition, the clear majority (72%) responded that children deserve more aggressive resuscitative efforts than adults. Paramedics feel relatively uncomfortable with the concept of terminating resuscitation efforts in children in the pre-hospital setting.

How far is that by air? The derivation of an air:ground coefficient

The objective of this study was to derive a simple equation to convert distances between air miles traveled by a helicopter and ground miles traveled by an ambulance. We performed a retrospective analysis of a convenience sampling of 245 “lights and sirens” ground ambulance transports between 1993 and 1997. Ground distances were recorded from odometer miles for each transport. Air miles were calculated using the Global Positioning System (GPS), measuring the distance in a straight line from the scene to the hospital. Air and ground distances were entered into a computerized spreadsheet, and the correlation coefficient and regression equation were derived. A simple approximation equation was developed and compared against the derived regression equation. There was a strong linear correlation between ground miles and air miles at virtually all distances studied (R = 0.932, R 2 = 0.869). Regression analysis revealed the following relationship: Ground miles = 0.94 + 1.25 (air miles). This was simplified to an approximation of: Ground miles = 1.3 (air miles). The approximation equation yielded an answer within 1 mile of the regression equation for distances up to 40 air miles. It is concluded that in a mixed rural and urban EMS system, one may convert air and ground mileage estimates by using the simple relationship: Ground miles = 1.3 (air miles). This conversion coefficient may prove useful for EMS personnel in designing reasonable helicopter utilization policies, making accurate transport decisions and conducting research.

An accurate tool for measuring ED saturation levels in an urban EMS system: Phoenix's year-long experience

An accurate tool for measuring ED saturation levels in an urban EMS system: Phoenix's year-long experience

Implementation of standing field treatment protocols in an urban EMS system

The objective was to describe our experience with implementation of standing field treatment protocols (SFTP) in a large, urban EMS system. A prospective, consecutive observational study examining the first 21 days of implementation of SFTPs in the City of Los Angeles, California. SFTPs were developed for 7 medical chief complaints and all major trauma patients. There were 13,586 EMS incidents, of which 4,037 (30%) received ALS treatment. SFTPs were used on 2,177 of these incidents, representing 54% of all ALS runs and 16% of all EMS incidents. The most frequently used SFTPs were for altered level of consciousness (29%), and chest pain (25%). The most common errors found were failure to document reassessment of the patient after each medication administration (45% fallout rate), and failure to document and attach a copy of the ECG to the EMS report (40%). The mean fallout rate for failure to establish or attempt IV access, administer oxygen, or provide cardiac monitoring was 7%. Out of 1,450 incidents with outcome data provided by the receiving hospitals, only 3 cases (2%) involved incorrect treatment, with an additional 2 involving the unnecessary use of lidocaine. None of these instances resulted in adverse effects or complications. SFTPs were integrated into a large EMS system with few procedural errors or adverse outcomes.

D O W ARNING L IGHTS AND S IRENS R EDUCE A MBULANCE R ESPONSE T IMES ?

Objective. To determine the time saving associated with lights and siren (L&S) use during emergency response in an urban EMS system. Methods. This prospective study evaluated ambulance response times from the location at time of dispatch to the scene of an emergency in an urban area. A control group of responses using L&S was compared with an experimental group that did not use L&S. An observer was assigned to ride along with ambulance crews and record actual times for all L&S responses. At a later date, an observer and an off-duty paramedic in an identical ambulance retraced the route—at the same time of day on the same day of the week—without using L&S and recorded the travel time. Response times for the two groups were compared using paired t-test. Results. The 32 responses with L&S averaged 105.8 seconds (1 minute, 46 seconds) faster than those without (95% confidence interval: 60.2 to 151.5 seconds, p = 0.0001). The time difference ranged from 425 seconds (7 minutes, 5 seconds) faster with L&S to 210 seconds (3 minutes, 30 seconds) slower with L&S. Conclusion. In this urban EMS system, L&S reduce ambulance response times by an average of 1 minute, 46 seconds. Although statistically significant, this time saving is likely to be clinically relevant in only a very few cases. A large-scale multicenter L&S trial may help address this issue on a national level.

T HE O UT-OF-HOSPITAL U SE OF A D OMESTIC V IOLENCE S CREEN FOR A SSESSING P ATIENT R ISK

Objectives. To determine the following: 1) whether a Domestic Violence Scene Assessment Screen (DVSAS) is accurate at predicting domestic violence (DV) when compared with results on the validated Abuse Assessment Screen (AAS), and 2) whether EMTs can perform accurately on a DVSAS after they have finished a transport so as not to interfere with routine care. Methods. All patients transported by ambulance from domestic environments (i.e., home) by an urban EMS system were included in the study. A ten-question screen was developed to assess whether a domestic environment had a high risk of having DV (DVSAS). A positive answer to any of the questions was considered to be a positive result on the screen. A trained observer with no clinical duties rode on the ambulance for randomized shifts during a two-month period. The observer completed the DVSAS while at the scene, then the patient, if able, completed the AAS. After finishing the transport, the EMT completed the DVSAS based on his or her memory of the scene. Results of the observer DVSAS were compared with the results of the EMT DVSAS and with the AAS. Results. A total of 43 transports from domestic scenes were included in the study. The observer DVSAS alone was positive in five cases (12%), the EMT DVSAS alone was positive in five cases (12%), and both were positive in seven cases (17%). Agreement between the EMT and the observer yielded a kappa of 0.56 adjusted for chance. Of 15 (42%) patients able to complete the AAS, one (7%) was positive on the AAS alone, four (27%) were positive on the observer DVSAS alone, and three (29%) were positive on both. The observer DVSAS agreed with the AAS results in ten of 15 (66%) of cases. When compared with the AAS, the observer DVSAS had a sensitivity of 75%, specificity of 55%, positive predictive value of 38%, and negative predictive value of 86%. Conclusion. Emergency medical technicians can complete the DVSAS at the end of a transport with good agreement with results obtained by an independent observer at the scene. The DVSAS is able to reflect the results of the AAS with moderate to good agreement.

A Time-Motion Study of the Emergency Medical Services Turnaround Interval

Study objective: Because overall EMS system response depends on ambulance availability, we conducted a prospective study of the EMS turnaround interval. This interval represents the time elapsed from ambulance arrival at the hospital until the ambulance reports back in service. Methods: An on-site observer, while monitoring EMS radio traffic, recorded the delivery and recovery activities of personnel from a large urban EMS system at a university hospital emergency department. System policy permitted a maximum turnaround interval of 30 minutes. Prospectively defined subintervals were analyzed. Results: A convenience sample of 122 patient deliveries was collected. Observed and radio-reported times of arrival at the hospital differed by -1′24" to +11'08". In 18.9% of cases, arrival was reported on radio more than 5 minutes after the observed arrival. Time from arrival to removal of the patient from the ambulance averaged 59" (range, 13" to 2′53"), and time from patient removal to emergency department entry averaged 42" (range, 10" to 5′22"). Time from ED entry to placement of the patient on an ED bed averaged 2′11" (range, 33" to 9′35"). Although the mean interval for the verbal report to ED staff was 33" (range, 13" to 2′53"), it was 15" or less in 36% of cases. Writing the ambulance call report took an average of 17′12" (range, 5′20" to 52′11"). The mean time off radio was 29′51" (range, 11′43" to 53′37"), and the mean time the ambulance was actually at the ED was 30′01" (range, 11′25" to 1°17′53"). Observed and radio-reported ambulance departure times differed by -4′31" to +23′32". In 22% of cases, departure was reported by radio more than 5′ after actual departure. Conclusion: In this system, ambulance call report documentation required the greatest subinterval of turnaround interval. The turnaround interval and its subintervals varied widely, and radio contact times correlated poorly with observed times at the ED. Attempts at improvement of overall system response through active management of the turnaround interval may be frustrated by reliance on radio-reported availability. [Cone DC, Davidson SJ, Nguyen Q: A time-motion study of the emergency medical services turnaround interval. Ann Emerg Med February 1998;31:241-246.]