Rural Emergency Medical Services System Research Articles

Guest Editorial: AAENP Releases Position Statement: The Role of Nurse Practitioners in Emergency Medical Services.

Recently, there has been a national discussion about nurse practitioners (NPs) working within emergency medical services (EMS). The National Association of EMS Physicians, the Society for Emergency Medicine Physician Assistants (SEMPA), and most recently, the American Academy of Emergency Nurse Practitioners (AAENP) have all issued position statements on this issue (AAENP, 2022; SEMPA, 2021; Wright et al., 2021). The joint mission should be centered around high-quality patient care, a multidisciplinary team, and elevating the level of NP practice available in the prehospital and interfacility settings. NPs working in prehospital roles can add value to rural, suburban, and urban environments. In rural America, providing adequate EMS response creates challenges for ambulance providers (National Rural Health Association, 2018). Urban EMS programs are already utilizing NPs as a potential solution to augment care delivery within the EMS system in various roles (Sanko et al., 2020). However, NPs face regulatory challenges, limiting or prohibiting more active involvement in the EMS system. According to the American Association of Nurse Practitioners (AANP), NPs in full practice authority states are more likely to practice in rural and underserved areas (AANP, 2022). To enable NPs to contribute more to prehospital care, national health care practice models and state regulators must consider rule changes that strengthen the utilization of NPs in EMS systems. NPs with appropriate training are in an ideal space to support rural EMS systems. In addition, there are barriers to NPs working in EMS leadership roles. One of the most significant barriers is the National Registry of Emergency Medical Technicians (NREMT, 2019) requirement that all paramedics and advanced emergency medical technicians have a physician medical director. This rule becomes problematic in some of the most rural areas of the country that struggle to find medical direction. Although medical directors trained in EMS fellowships may be ideal, the physician-only language written in NREMT's guidelines marginalizes rural health care and prevents qualified NPs from participating in certain levels of medical direction. AAENP (2022) believes that “NPs are uniquely positioned to provide and direct care of the patient within a multidisciplinary EMS system. The AAENP supports utilization of NPs in EMS to the full extent of their licensure, education, and scope of practice based on state and agency regulations.” —Wesley D. Davis, DNP, ENP-C, FNP-C, AGACNP-BC, CEN, FAANP, FAEN Family and Emergency Nurse Practitioner Program Coordinator and Assistant Professor, College of Nursing University of South Alabama Mobile, Alabama —Chivas Guillote, DNP, ENP, FNP, AGACNP, LP Vice President of Clinical Services Harris County Emergency Corps Houston, Texas Guest Editors

Validation of field assessment stroke triage for emergency destination for prehospital use in a rural EMS system.

Field Assessment Stroke Triage for Emergency Destination (FAST-ED) is a simple and accurate prehospital stroke severity scale that has been shown to have comparable accuracy to the gold standard National Institutes of Health Stroke Scale (NIHSS) but requires further field validation for use by emergency medical services (EMS), particularly in rural systems. FAST-ED scores ≥4 are considered high probability for large vessel occlusion (LVO) strokes, while scores <4 are low to moderate probability for LVO. The objective of this study was to assess inter-rater reliability of the EMS FAST-ED (EMS) score to the emergency department FAST-ED (ED-MD) scores. EMS calculated FAST-ED scores prior to transport to the emergency department (ED) on patients with a positive prehospital stroke screen. EDMD calculated FAST-ED scores for the same patients upon arrival to the ED. Interrater reliability and test characteristics were calculated. A total of 95 patients were included in this study and 14 were subsequently diagnosed with an LVO. EMS assigned 34 patients (35.8%) a FAST-ED score of ≥4. EDMD assigned 25 patients (26.3%) a FAST-ED score of ≥4. Using the clinical cut-points of FAST-ED scores <4 and ≥ 4, a linearly weighted Cohen's kappa coefficient showed moderate interrater reliability when comparing EMS and EDMD scores (kw 0.44, 95% CI 0.25-0.63). At ≥4, EMS FAST-ED scores had a sensitivity 0.48, specificity 0.75, PPV 0.62, NPV 0.62 for predicting an LVO, while EDMD FAST-ED scores had a sensitivity 0.36, specificity 0.82, PPV 0.64, NPV 0.60. Comparable receiver operator curve area under the curve values were obtained. EMS and EDMD FAST-ED scores were moderately comparable in a rural EMS system. Similar NPVs compared to EDMD suggest the use of FAST-ED as an appropriate screening tool for EMS to predict the probability of LVO in the prehospital setting and make destination determinations regarding primary transport to a thrombectomy-capable stroke center.

Administration of epinephrine by advanced emergency medical technicians for out-of-hospital cardiac arrest in a rural emergency medical services system.

ObjectiveEpinephrine in out‐of‐hospital cardiac arrest (OHCA) remains controversial and understudied in rural emergency medical services (EMS) systems. We evaluated the effects of allowing advanced emergency medical technicians (AEMTs) to administer epinephrine during OHCA in a rural EMS system.MethodsAn interrupted time series study was conducted using statewide EMS electronic records. Patients with OHCA before (phase I) and after (phase II) a protocol change expanding the AEMT scope of practice to include epinephrine for OHCA were identified. Number and timing of initial epinephrine administration, return of spontaneous circulation, and 30‐day survival rates were compared using descriptive statistics, logistic regression, regression discontinuity, and propensity score matching.ResultsA total of 1037 OHCAs met the inclusion criteria. In phase 1 compared with phase 2, 275 (56.12%) patients received epinephrine versus 624 (83.53%; P < 0.001). The mean time to first administration of epinephrine for unwitnessed and bystander‐witnessed OHCA were 11.73 minutes versus 8.17 minutes (P < 0.001) and 11.59 minutes versus 8.85 minutes (P < 0.01), respectively. Unadjusted analysis showed a decrease in 30‐day survival rates among patients receiving epinephrine from 18.01% to 12.66% (P < 0.05). Adjusted analysis showed an increase in 30‐day survival with decreased time to first epinephrine dose(OR 0.960, 1.005; 95% confidence interval, 0.929, 0.992).ConclusionAdding epinephrine for OHCA to the AEMT scope of practice was associated with an increased percentage of patients receiving epinephrine and decreased time to first administration of epinephrine for patients with unwitnessed OHCA. Unadjusted analysis showed a decrease in 30‐day survival rates among patients receiving epinephrine. Adjusted analysis found that earlier administrationof epinephrine was associated with increased ROSC and 30‐day survival.

Rural Stroke Patients Have Higher Mortality: An Improvement Opportunity for Rural Emergency Medical Services Systems.

Early recognition and prompt prehospital care is a cornerstone of acute stroke treatment. Residents of rural areas have worse access to stroke services than urban residents. The purpose of this study was to (1) describe US trends in rural-urban stroke mortality and (2) identify possible factors associated with rural-urban stroke case-fatality disparities. This study was a nationwide retrospective cohort study of stroke admissions. The primary exposure was rurality of patient's residence. The primary outcome was death during hospital encounter. The secondary outcome was discharge to a care facility or home healthcare. Univariable and multivariable logistic regressions estimated the odds of mortality by subject rurality among stroke subjects. Rural stroke subjects had higher mortality than nonrural counterparts (18.6% rural vs 16.9% nonrural). After adjustment for patient and hospital factors, patient rurality was associated with increased odds of mortality (aOR = 1.11; 95% CI: 1.06-1.15; P < .001). For the secondary outcome of discharge to home, rural stroke subjects were less likely to be discharged to a care facility than nonrural stroke visits (aOR 0.94; 95% CI: 0.91-0.97; P < .001). Results were similar after adjusting for thrombolytics administration and transfer status. Rural stroke patients have higher mortality than their urban counterparts likely due to their increased burden of chronic disease, lower health literacy, and reduced access to prompt prehospital care. There may be an opportunity for emergency medical services systems to assist in increasing stroke awareness for both patients and clinicians and to establish response patterns to expedite emergency care.

Impact of a "Team-focused CPR" Protocol on Out-of-hospital Cardiac Arrest Survival in a Rural EMS System.

More than 300,000 persons in the United States experience an out-of-hospital cardiac arrest every year. The American Heart Association emphasizes on the rapid, effective delivery of cardiac arrest interventions by bystanders and emergency medical services (EMS) on scene. In July 2013, the EMS of Randolph County, a rural county in central North Carolina, implemented a team-focused cardiopulmonary resuscitation(CPR) protocol. The protocol emphasized early chest compressions and resuscitation on scene until the return of spontaneous circulation (ROSC) or until efforts were deemed futile. Data were collected on all cardiac out-of-hospital cardiac arrest cases from June 30, 2012 to June 30, 2014. Outcomes for the year before the institution of the team-focused CPR protocol were compared with rates for the year following implementation. A significantly higher proportion of patients achieved ROSC after protocol implementation: 25/38 [66%, 95% confidence interval (CI), 49%-80%] versus 19/67 (28%; 95% CI, 18-41%, P < 0.001). More patients survived to hospital admission in the team-focused CPR group (16/38, 42.1%, 95% CI, 26%-59%) versus the preprotocol period (10/67, 14.9%, 95% CI, 7.4%-26%, P = 0.004). Although survival to discharge was higher in the team-focused protocol period (6/38, 15.8%, 95% CI, 6.0%-31%) than the preprotocol period (4/67, 6.0%, 95% CI, 1.7%-14.6%), this did not meet statistical significance (P = 0.16). The introduction of a team-focused CPR protocol in a single rural county-based EMS system dramatically improved ROSC and hospital admission rates, but not survival to discharge. Continued surveillance, as well as evaluation and optimization of inpatient care, is warranted.

Analysis of Complaints in a Rural Emergency Medical Service System

The health care industry is increasingly focused on customer service, one aspect of which is dealing with customer complaints. The purpose of this study was to assess the prevalence and nature of complaints against prehospital providers in a rural Emergency Medical Services (EMS) system. This retrospective study of logged complaints utilized data from May 28, 1999 through September 26, 2008. All complaints were investigated by a single trained staff member of the regional EMS office. He interviewed witnesses, and reviewed statements and other documentation related to the complaints. Each complaint was classified into one of four categories: (1) operational; (2) clinical; (3) educational; or (4) customer service. In addition, each complaint was examined to determine if the grievance was founded. The study was conducted in a seven-county region of western Pennsylvania with a population of 639,641 and more than 3,000 EMS providers. There were 110 complaints over a nine-year period (approximately 12 per year). Forty were considered unfounded complaints (43%) and 49 persons (45%) had made more than a single complaint. No EMS provider had an EMS certification suspended or revoked based on a clinically-related complaint. The data revealed a substantial number of complaints for which insufficient information was available to allow a conclusion based on reasonable certainty or the degree of certainty expected of a reasonable person evaluating the facts. One hundred ten complaints were logged for the study EMS program. No complaints violated treatment protocols. Forty complaints were unfounded. There were 49 "repeat" complaints against providers who had previously had complaints made against them.

Prehospital Administration of Tenecteplase for ST-segment Elevation Myocardial Infarction in a Rural EMS System

Introduction. In the setting of ST-segment elevation myocardial infarction (STEMI), early reperfusion yields better patient outcomes. Emergency medical services (EMS) is the first medical contact for half of the afflicted population, and prehospital thrombolysis may result in considerably faster reperfusion compared with percutaneous coronary intervention (PCI) in rural settings. However, there are few reports of prehospital thrombolysis in rural EMS systems. Objective. To describe a rural EMS system's experience with tenecteplase in STEMI. Methods. Data were retrospectively abstracted from the medical records of patients receiving tenecteplase using standard chart review guidelines. Primary outcomes included time saved by EMS-initiated thrombolysis, aborted infarctions, serious bleeding events, and in-hospital mortality. Secondary outcomes included reinfarction, rescue angioplasty, and appropriateness of treatment. Time savings was defined as transport time after tenecteplase administration plus 90 minutes, which is the typical door-to-balloon time for PCI laboratories. Aborted infarction was defined as resolution of the cumulative ST-segment elevation to ≤50% of that on the initial electrocardiogram (ECG) within two hours after treatment, and peak creatine kinase (CK)/CK-MB levels less than or equal to twice the upper limit of normal. Results. Seventy-three patients received prehospital tenecteplase; this treatment was determined to be appropriate in 86.4% of cases. The mean patient age was 59 years, and 71.6% of the patients were male. Mean (± standard deviation) scene-arrival-to-drug time was 26.2 (±11.4) minutes, the mean scene-arrival-to-hospital-arrival time was 73.0 (±20.6) minutes, and the mean transport time was 46.0 (± 11.1) minutes. Tenecteplase was administered 35.9 (±25.0) minutes prior to hospital arrival, and the estimated reperfusion time savings over PCI was 125.9 (±25.0) minutes. Aborted infarctions were observed in 24.1% of patients, whereas 9.6% suffered reinfarction, 47.9% underwent rescue angioplasty, and 16.7% required coronary artery bypass grafting (CABG). Serious bleeding events occurred in 15 patients (20.5%), and four (5.5%) died. Conclusion. In this retrospective review of rural STEMI patients, tenecteplase was administered 36 minutes prior to hospital arrival, saving approximately two hours over typical PCI strategies and resulting in aborted infarctions in one-fourth of patients. In a rural setting with lengthy transport times to PCI facilities, tenecteplase appears to be a feasible prehospital intervention. Randomized controlled trials are needed to fully evaluate the safety and effectiveness of this intervention prior to widespread adoption.

Use of Continuous Positive Airway Pressure in Rural Emergency Medical Services Systems for Acute Pulmonary Edema

Use of Continuous Positive Airway Pressure in Rural Emergency Medical Services Systems for Acute Pulmonary Edema

Adequacy of musculoskeletal pain control by emergency medical services providers compared to an emergency department gold standard

Study objectives: Pain management by emergency medical services (EMS) personnel has received limited attention in the literature. We examine the adequacy of EMS pain control for musculoskeletal complaints compared with the criterion standard of subsequent emergency department (ED) pain management. Methods: This retrospective, consecutive case series examined EMS and ED records for all patients who had a chief complaint of musculoskeletal pain and were transported in a 3-month period to the sponsor hospital by a suburban or rural paramedic EMS system. Data collected included demographics, pain medications given, adverse drug reactions, EMS disposition, and ED medications given within 1 hour of physician examination. Patients with major trauma or injuries greater than 2 weeks old were excluded. Data were analyzed descriptively. Institutional review board approval was obtained. Results: Age and sex were similar among groups. Patients were determined to need pain medications if treated by the ED or if they were treated by EMS and there was no documentation in the ED record that treatment was inappropriate. Using these criteria, 64 of 173 patients required pain medication. Of patients requiring pain medications, EMS treated 23% (n=15). Patients with evidence of fracture were more likely to receive EMS pain medications (5/11, 45%). There were only 2 EMS adverse drug reactions; in both cases, the patients were sleepy but easily arousable. Conclusion: Of all patients requiring pain medications, EMS failed to treat 77% (49/64). Potential reasons for EMS undertreatment of musculoskeletal pain include failure to recognize pain, fear of adverse reactions, underappreciation of pain morbidity, and absence of pain control education.

Out-of-hospital analgesia in adults and children

Study objectives: Numerous studies have assessed the delivery of analgesia in the emergency department; however, few have assessed analgesia delivery in the out-of-hospital setting. We describe the use of out-of-hospital analgesia in adults and children with suspected extremity fractures or burns. Methods: This was a retrospective review of all patient encounters in a statewide emergency medical services (EMS) database from January 2001 through December 2002. The statewide database consists of a mix of rural and small urban EMS systems with more than 200,000 annual patient encounters. Records for all patients with fractures or burns, excluding multisystem trauma and head injuries, were included. Data collected included age, type of injury, pain medication administration, and adjunctive therapies for fracture management. Interventions including oral suctioning, oral or nasal airway, bag-valve-mask ventilation, endotracheal intubation, cardiopulmonary resuscitation, and naloxone use were collected for patients receiving analgesia. This study was approved by the hospital institutional review board. Results: A total of 426,767 EMS runs were reviewed. Fractures or burns were identified in 25,647 patients. Of these, 21,393 patients were included in the study, with 4,254 meeting exclusion criteria. There were 2,120 (9.9%) patients younger than 18 years compared with 19,273 (90.1%) patients who were 18 years and older. Overall, 9.9% of patients received any type of analgesia. The rate of analgesia use in patients younger than 18 years was 13.0% (95% confidence interval [CI] 11.6% to 14.5%). For patients 18 years and older, 9.5% received analgesia (95% CI 9.1% to 10%). Of the 20,584 patients with fractures, 49.7% (95% CI 47.5% to 51.9%) of children and 23.2% (95% CI 22.6% to 23.8%) of adults were splinted. Cold application for patients with fractures occurred in 38.0% (95% CI 37.5% to 42.0%) of children and 14.8% (95% CI 14.3% to 15.3%) of adults. An intravenous line was placed in 21.9% of children and 22.3% of adults. Adults receiving analgesia were more likely to undergo an intervention for airway or vascular compromise compared with those receiving no analgesia (1.1% versus 0.5%). Only 1 child (0.1%) who received analgesia required any of the airway or cardiac interventions. Conclusion: In this study, children were more likely to receive analgesia for their injuries compared with adults. In addition, children were more likely to receive adjunctive therapy for fracture management. The need for airway or cardiac interventions in patients receiving analgesia was limited. The overall rate of analgesia delivery remains low.

Paramedic judgment of the need for trauma team activation for pediatric patients.

To determine the value of paramedic judgment in determining the need for trauma team activation (TA) for pediatric blunt trauma patients. A prospective, observational study was conducted at the ED of Children's Hospital Medical Center of Akron between July 12, 1996, and February 28, 1997, in cooperation with Akron Fire Department emergency medical technician-paramedics (EMT-Ps). The ED provides on-line and off-line medical control for pediatric transports. Patients with minor or no identifiable injuries are released at the scene with the instructions to see a physician. The remainder are transported to the ED. The decision for TTA is based on ED trauma protocols as well as emergency physician judgment of injury severity in combination with the judgment of the treating paramedic. During the study, EMT-Ps were asked (before physician input) whether, based solely on their judgment, a patient needed TTA. Patients 0-14 years old who were involved in motor vehicle crashes, bike crashes, or falls from a height of >10 feet were included in the study. TTA was defined as necessary if the patient was admitted to the intensive care unit (ICU) or operating room (OR) for nonorthopedic surgical procedures. Out-of-hospital, ED, and hospital records were reviewed. Coroners' records as well as medical records of all trauma admissions during the study period were reviewed to ensure that the patients released at the scene were not mistriaged. One hundred ninety-two patients met study criteria. Eighty-five patients (44%) were transported to the ED, of whom 12 had TTA. EMT-Ps requested TTA for 10 of these patients, and 2 patients had TTA per ED trauma protocol. Two of the patients who were judged by EMT-Ps to need TTA were admitted to the ICU/OR, and neither of the patients identified by ED trauma protocol to require TTA were admitted to the ICU/OR. Two initially stable patients who did not have TTA deteriorated after arrival to the ED. Both were admitted to the ICU. The sensitivity and specificity of paramedic judgment of the need for TTA for pediatric blunt trauma patients were 50% (95% CI 9.2-90.8) and 87.7% (95% CI 78.0-93.6), respectively. The positive and negative predictive values were 16.7% (95% CI 2.9-49.1) and 97.3% (95% CI 89.6-99.5). None of the patients released at the scene was mistriaged based on the review of the coroners' and trauma admission records. Results of this investigation indicate that a small percentage of pediatric blunt trauma patients require TTA. EMT-P judgment alone of the need for TTA for pediatric blunt trauma patients is not sufficiently sensitive to be of clinical use. The low sensitivity is explained by the deterioration in the clinical condition of 2 initially stable patients. The paramedic disposition decisions from the scene were always accurate. Nontransport by emergency medical services (EMS) may be acceptable in some uninjured pediatric trauma patients. Injured pediatric trauma patients who appear to be stable may deteriorate shortly after injury. However, if a pediatric patient appears injured, transport from the scene and examination by a trauma specialist are needed. Finally, the role of paramedic judgment must be further defined by larger studies with urban, rural, and suburban EMS systems before it can be used as a sole predictor of TTA.

Does basic life support in a rural EMS system influence the outcome of patients with respiratory distress?

The purpose of this study was to determine whether basic life support, prehospital emergency medical care in a rural area affects the hospital course of patients with respiratory distress. Medical records for patients admitted from the emergency department with a discharge diagnosis related to respiratory disease were reviewed. Data collected included: 1) mode of arrival; 2) initial symptom; 3) vital signs; 4) prehospital interventions applied; 5) hospital days; 6) discharge status; and 7) principal diagnosis. Multiple logistic regression analysis was used to predict length of hospital stay. Charts for 603 patients were reviewed. Complete data for all variables included in the logistic regression analysis were available for 471 patients (78.1%). Because 55 patients died, only 416 (69.0%) were included in the multiple regression analysis conducted to predict length of hospital stay. Logistic regression analysis demonstrated that patients who arrived by ambulance and older patients were more likely to die; patients with higher systolic blood pressures were more likely to survive. Only patient age predicted length of hospital stay, with older patients having longer stays. Basic life support prehospital care in this rural emergency medical services system does not result in a lower mortality rate or a shorter hospital stay for a broad group of patients with respiratory distress who require hospital admission. Although this study is limited to a single population and a single emergency medical services system, it is one of only a few studies of outcome in basic life support systems.

Simplifying the assessment of rural emergency medical service trauma transport.

The authors determine whether assessments of effects of rural emergency medical services (EMS) system characteristics on trauma outcomes using patient-level data are biased significantly if the Injury Severity Score (ISS) is not available. Data are taken from ambulance trip reports merged with the trauma registry data for the Georgia EMS region VI trauma center hospital, located in Augusta. All 294 trauma patients for the rural counties surrounding Richmond County for the calendar year 1991 who were not dead at the scene and who were treated at the trauma center are included. A 20% random sample of trauma patients from Richmond county from May 1991 to September 1991 not dead at the scene and treated at the trauma center yielded an additional 96 cases. Excluding 43 patients with missing data yields 347 trauma cases with 18 trauma deaths. A logistic regression model for trauma mortality is estimated using the Revised Trauma Score, ISS, type of trauma, and patient age (analogous to the standard Trauma Related Injury Severity Score model). The predicted probability of patient mortality from this model is compared with the predicted probability of mortality when the logistic regression model omits ISS. Correlations between the difference in predicted probability (ie, the error in predicted probability associated with the omitted ISS variable) and EMS system characteristics are determined. Although ISS adds to the predictive power of the trauma outcome model, the errors in predicted probabilities associated with the omission of ISS generally are small and uncorrelated with patient or EMS system characteristics, with the exception of patient gender. In rural settings, where a patient's ISS generally is not available, studies of rural EMS system characteristics and trauma outcomes may use Revised Trauma Score, patient age, and type of trauma to control for expected survival. The patient's ISS does not appear to be essential, at least for the rural area analyzed in this study.

Use of end-tidal carbon dioxide to predict outcome in prehospital cardiac arrest: Ann Emerg Med 1995; 25/6: 762–767

Abstract Study objective: End-tidal CO 2 (ETCOH 2 ) measurement can be used to predict death in prehospital cardiac arrest patients with pulseless electrical activity (PEA). Design: A prospective, observational study. Setting: An urban and rural emergency medical services system in northwestern Washington state. Participants: Ninety consecutive victims of prehospital cardiac arrest with PEA. Interventions: Patients were intubated in the field and treated using standard advanced cardiac life support protocols with on-line medical control. In addition, all patients were evaluated using mainstream ETCO 2 monitoring. In this study, a hypothetical decision was made to cease resuscitative efforts based on an ETCO 2 level of 10 mm Hg or less after 20 minutes of advanced cardiac life support. Results: The study included 90 patients (61 were men) with a mean age of 67.6±13.6 years (range, 27 to 95 years). The initial ETCO 2 averaged 11.7±6.6 mm Hg in nonsurvivors (range, 5 to 50 mm Hg) and 10.9±4.9 mm Hg in survivors (range, 5 to 24 mm Hg) ( P >.672 [NS]). After 20 minutes of advanced cardiac life support, ETCO 2 averaged 3.9±2.8 mm Hg (range, 0 to 12 mm Hg) in patients in whom the theoretical decision was made to cease field resuscitation. In contrast, survivors' ETCO 2 , just before restoration of circulation, averaged 31±5.3 mm Hg (range, 16 to 35 mm Hg) ( P <.0001). Using an ETCO 2 of 10 mm Hg or less as a theoretical threshold to predict death in the field successfully discriminated between the 16 survivors to hospital admission (those that achieved return of spontaneous circulation) and 75 prehospital deaths. Of the 16 survivors to hospital admission, 9 died in the hospital, and 7 were discharged from the hospital alive. In 13 of the 16 survivors, the first evidence of return of spontaneous circulation, before a palpable pulse or blood pressure, was a rising ETCO 2 . The logistic-regression parameters for the model are 4.4391+ETCO 2* -0.3624 ( P Conclusion: This study suggests that a low ETCO 2 (10 mm Hg or less) can be used to predict irreversible death in patients with pulseless electrical activity undergoing prehospital advanced cardiac life support. If future studies validate this model, use of ETCO 2 may allow for triage decisions in the field. [Wayne MA, Levine RL, Miller CC: Use of end-tidal carbon dioxide to predict outcome in prehospital cardiac arrest. Ann Emerg Med June 1995;25:762-767.]

Use of End-Tidal Carbon Dioxide to Predict Outcome in Prehospital Cardiac Arrest

Study objective: End-tidal CO 2 (ETCOH 2) measurement can be used to predict death in prehospital cardiac arrest patients with pulseless electrical activity (PEA). Design: A prospective, observational study. Setting: An urban and rural emergency medical services system in northwestern Washington state. Participants: Ninety consecutive victims of prehospital cardiac arrest with PEA. Interventions: Patients were intubated in the field and treated using standard advanced cardiac life support protocols with on-line medical control. In addition, all patients were evaluated using mainstream ETCO 2 monitoring. In this study, a hypothetical decision was made to cease resuscitative efforts based on an ETCO 2 level of 10 mm Hg or less after 20 minutes of advanced cardiac life support. Results: The study included 90 patients (61 were men) with a mean age of 67.6±13.6 years (range, 27 to 95 years). The initial ETCO 2 averaged 11.7±6.6 mm Hg in nonsurvivors (range, 5 to 50 mm Hg) and 10.9±4.9 mm Hg in survivors (range, 5 to 24 mm Hg) ( P >.672 [NS]). After 20 minutes of advanced cardiac life support, ETCO 2 averaged 3.9±2.8 mm Hg (range, 0 to 12 mm Hg) in patients in whom the theoretical decision was made to cease field resuscitation. In contrast, survivors' ETCO 2, just before restoration of circulation, averaged 31±5.3 mm Hg (range, 16 to 35 mm Hg) ( P<.0001). Using an ETCO 2 of 10 mm Hg or less as a theoretical threshold to predict death in the field successfully discriminated between the 16 survivors to hospital admission (those that achieved return of spontaneous circulation) and 75 prehospital deaths. Of the 16 survivors to hospital admission, 9 died in the hospital, and 7 were discharged from the hospital alive. In 13 of the 16 survivors, the first evidence of return of spontaneous circulation, before a palpable pulse or blood pressure, was a rising ETCO 2. The logistic-regression parameters for the model are 4.4391+ETCO 2*-0.3624 ( P<.0001). Sensitivity was 97.3%; specificity 100%; positive predictive value 100%; and negative predictive value 88.9%. Conclusion: This study suggests that a low ETCO 2 (10 mm Hg or less) can be used to predict irreversible death in patients with pulseless electrical activity undergoing prehospital advanced cardiac life support. If future studies validate this model, use of ETCO 2 may allow for triage decisions in the field. [Wayne MA, Levine RL, Miller CC: Use of end-tidal carbon dioxide to predict outcome in prehospital cardiac arrest. Ann Emerg Med June 1995;25:762-767.]

Public perceptions of a rural emergency medical services system.

To determine the awareness of citizens and physicians concerning the capabilities of a rural emergency medical services (EMS) system. Citizens and physicians are unaware of the capabilities of the EMS system. Residents were selected randomly from the local telephone directory and asked a series of structured questions about their EMS agency. A written survey was distributed to area physicians. Chi-square analysis was used to compare the proportion of respondents who knew the available interventions in their community with the proportion of those who did not. Statistical significance was inferred at p < 0.01. A total of 49% of the citizens were able to identify available skills, and 41.4% of the physicians were able to identify available skills. Physicians were less likely than were the citizens to be able to identify the skills performed by each provider (p < 0.001). This study indicates that both physicians and the lay public have little understanding of the capabilities of their EMS system.

Simulation modelling of emergency medical services

This paper deals with the problem of application of simulation modelling in Emergency Medical Services (EMS) systems. Approaches to modelling of EMS are discussed and a review of EMS simulation models is presented. A simple simulation model of a rural EMS system in Poland is described. Some results of the initial application of the model are presented. Possibilities of simulation modelling for solving EMS managerial and planning problems are briefly analysed.

An analytic method for the evaluation of rural Emergency Medical Service development.

An analytic method is presented for assessing the marginal impact of incremental changes in rural Emergency Medical Services (EMS) on cardiac mortality, morbidity, EMS system process and performance, and health care system utilization. The method incorporates a model of the EMS system. This model specifies five sets of interactive variables characterizing EMS system development and effectiveness. The analytic method quantifies the contribution of each of these sets of interactive variables on the outcome variables (cardiac mortality, morbidity, EMS process/performance, and health care system utilization) for three target populations: those who utilize the EMS system, all hospitalized patients with acute ischemic heart disease independent of EMS system use, and the population of all patients dying from acute ischemic heart disease on a communitywide basis. By including in the model those factors unique to rural areas, such as scarcity of fiscal and health care system resources, geographical constraints, and the skewed severity of case mix due to the clinical and socioeconomic conditions found among rural patients, the analytic method is able to quantify and help explain the impact of these factors on the EMS system and the limitations which they impose. The analytic method affords planners and administrators and rational basis for decisions regarding future rural EMS system development through its identification of those system characteristics amenable to change and worth pursuing from a health policy perspective.