Can quantitative capnometry differentiate between cardiac and obstructive causes of respiratory distress?

STUDY OBJECTIVE

To determine whether quantitative measurement of end-tidal carbon dioxide (ETCO2) can differentiate between cardiac and obstructive causes of respiratory distress.

DESIGN

Prospective observational study.

SETTING

Emergency department (ED) of a tertiary care hospital.

PATIENTS

Adult patients who presented to the ED with moderate-to-severe dyspnea. Patients were excluded if they were unable to cooperate with the performance of peak expiratory flow rate (PEFR) or ETCO2 tests, were younger than 18 years of age, or had received prehospital intervention for their respiratory distress.

INTERVENTIONS

Physicians obtained an ETCO2 level and PEFR prior to ED pharmacologic intervention. A hand-held capnometer with digital read-out was used to obtain the ETCO2 level. The patient's age, sex, initial vital signs, breath sounds and medication history, the presence or absence of diaphoresis and/or orthopnea, the duration of symptoms, the chest radiograph interpretation, and final diagnosis were also recorded.

MEASUREMENTS AND RESULTS

Forty-two patients were eligible for inclusion in the analysis. The mean ETCO2 level was 31.1+/-9.4 mm Hg; the mean PEFR was 161.3+/-53.1 L/min. The ETCO2 levels for pulmonary edema/congestive heart failure (CHF) patients differed significantly from those of asthma/COPD patients (27.1+/-7.8 mm Hg vs 33.4+/-9.6 mm Hg; p=0.0375). However, no single ETCO2 level was found to be a reliable predictor of diagnosis.

CONCLUSION

ETCO2 levels for pulmonary edema/CHF patients differ significantly from those of asthma/COPD patients. However, no single ETCO2 level reliably differentiates between the two disease processes.

Can EMS providers adequately assess trauma patients for cervical spinal injury?

OBJECTIVE

To determine whether EMS providers can accurately apply the clinical criteria for clearing cervical spines in trauma patients.

METHODS

EMS providers completed a data form based on their initial assessments of all adult trauma patients for whom the mechanism of injury indicated immobilization. Data collected included the presence or absence of: neck pain/tenderness; altered mental status; history of loss of consciousness; drug/alcohol use; neurologic deficit; and other painful/distracting injury. After transport to the ED, emergency physicians (EPs) completed an identical data form based on their assessments. Immobilization was considered to be indicated if any one of the six criteria was present. The EPs and EMS providers were blinded to each other's assessments. Agreement between the EP and EMS assessments was analyzed using the kappa statistic.

RESULTS

Five-hundred seventy-three patients were included in the study. The EP and EMS assessments matched in 78.7% (n = 451) of the cases. There were 44 (7.7%) patients for whom EP assessment indicated immobilization, but the EMS assessment did not. The kappa for the individual components of the assessments ranged from 0.35 to 0.81, with the kappa for the decision to immobilize being 0.48. The EMS providers' assessments were generally more conservative than the EPs'.

CONCLUSION

EMS and EP assessments to rule out cervical spinal injury have moderate to substantial agreement. However, the authors recommend that systems allowing EMS providers to decide whether to immobilize patients should follow those patients closely to ensure appropriate care and to provide immediate feedback to the EMS providers.

A comparison of oxygen administration practices of EMTs and emergency physicians

This study examined whether emergency medical technicians (EMTs) withhold oxygen from hypothetical patients whom emergency physicians would treat with high-flow oxygen, particularly chronic obstructive pulmonary disease (COPD) patients. A survey describing 12 hypothetical patients was distributed to 33 emergency physicians, 30 newly trained EMTs, and 27 experienced EMTs. For each patient, the respondents were asked to identify the most appropriate prehospital oxygen administration rate as "low flow" or "high flow". Using an alpha value of .05, chi 2 analysis was used to compare the frequency of high-flow oxygen administration for the three groups. Newly trained EMTs were significantly more likely than physicians to administer high-flow oxygen to patients with COPD who were not receiving home oxygen. Otherwise, the oxygen administration practices of EMTs were not inconsistent with those of emergency physicians.

The perceived importance of paramedic skills and the emphasis they receive during EMS education programs

OBJECTIVE

The National Standard Curriculum for paramedics is currently being revised. There is little scientific evidence of what does and what does not work in prehospital care, and of whether the National Standard Curriculum prepares paramedics for the field. To provide some basis for the current revisions to the National Standard Curriculum, the authors determined which prehospital skills are perceived by paramedics to be the most important, and whether the emphasis placed on those skills during initial and continuing education programs corresponds with the perceived importance.

METHODS

Surveys listing 21 paramedic skills were mailed to the directors of 41 EMS agencies who agreed to participate in the study. The directors distributed the surveys to 1,364 paramedics affiliated with their organizations. The participants were asked to rate the importance of each skill, and the emphasis placed on each skill during their initial and continuing education. Skills were ranked on a scale of 0 to 4, with 0 representing no importance or emphasis, and 4 representing the most possible importance or emphasis.

RESULTS

Six-hundred of the 1,364 (44%) surveys were returned. Respondents had a mean of 9.9 +/- 5.6 years of EMS experience, and 5.4 +/- 4.0 years of experience as paramedics. The three skills ranked highest in importance were: 1) endotracheal intubation; 2) defibrillation; and 3) assessment. Importance in prehospital care was ranked equal to or higher than emphasis in both initial and continuing education for all skills except splinting and urinary catheterization, which received higher rankings for emphasis in initial education. Emphasis in initial education equaled or exceeded the emphasis in continuing education for all skills except intraosseous infusion.

CONCLUSION

The perceived importance of most prehospital skills is very high, and exceeds the emphasis placed on those skills during both initial and continuing education programs. These findings have implications for medical directors, EMS instructors, and persons involved with the revision of the National Standard Curriculum.

Accuracy of rural EMS provider interpretation of three-lead ECG rhythm strips

OBJECTIVE

To measure the accuracy of lead II rhythm strip interpretations performed by advanced life support (ALS) emergency medical technicians (EMTs) in a rural emergency medical services (EMS) system.

METHODS

An electronic rhythm simulator was used to produce 24 three-lead electrocardiogram (ECG) rhythm strips. The rhythms were shown to 57 ALS EMTs participating in regularly scheduled continuing education classes. The participants were asked to identify the rhythms.

RESULTS

The three-lead ECG interpretations were generally accurate, although there was some difficulty in distinguishing between specific types of tachydysrhythmia and atrioventricular (AV) block. The overall accuracy of the rhythm interpretations was 79.2%, ranging from 45.6% (second-degree type II heart block) to 98.2% (sinus bradycardia). The sensitivity for specific tachydysrhythmias ranged from 68.4% (supraventricular tachycardia) to 86.0% (atrial fibrillation); the sensitivity for specific types of AV block ranged from 45.6% (second-degree, type II) to 71.9% (third-degree).

CONCLUSION

In this EMS system, ECG interpretations are generally accurate, with tachydysrhythmias and AV blocks being the source of most discrepancies.

A breathing manikin model for teaching nasotracheal intubation to EMS professionals

OBJECTIVE

The widespread use of orotracheal intubation with rapid-sequence induction has made it difficult for emergency medical services (EMS) professionals to gain experience in nasotracheal intubation (NTI) in a controlled and supervised setting. The purpose of this study was to determine whether a training session on NTI with a breathing manikin can be used to improve the self-assessed skill level and comfort of EMS professionals.

METHODS

A prospective trial was conducted with a convenience sample of 33 EMS professionals, previously trained in NTI techniques. For the training session, a Laerdal airway manikin was modified by replacing the lungs with self-inflating resuscitation bag. The bag could then be squeezed to simulate breathing, with an inspiratory and expiratory phase. Following didactic instruction, and with direct supervision, each participant practiced NTI using this breathing manikin. Each participant completed a questionnaire, both before and after the training session, to determine self-assessed comfort and skill level for both oral and nasal intubations (0 = lowest, 10 = highest). The pre- and postintervention scores were compared using the Wilcoxon signed-rank test, alpha = 0.01.

RESULTS

Following the training session, the comfort level for NTI by the participants increased significantly from a median value of 2 to 7 (p = 0.001). Furthermore, the self-assessed skill level for NTI following the training session increased significantly from a median value of 4 to 8 (p = 0.0001). As expected, there were no significant differences noted in self-assessed skill level for orotracheal intubation following the training session. However, there was statistically significant improvement in self-assessed comfort levels for orotracheal intubation after the skills laboratory, p = 0.0001.

CONCLUSION

For EMS professionals, a training session for NTI using a relatively inexpensive and easily assembled breathing manikin model increases both comfort and self-assessed skill level.

Effect of vital signs on advanced life support interventions for prehospital patients

OBJECTIVE

Routine vital signs assessment is considered a fundamental component of patient assessment. This study was undertaken to determine whether advanced life support (ALS) emergency medical services (EMS) providers depend on vital signs information in managing their patients.

METHODS

Emergency medical technician-paramedics (EMT-Ps) and EMT-Intermediates (EMT-Is) were presented with 20 randomized patient scenarios that did not included vital signs information. The participants were asked to identify all of the interventions they would perform for each hypothetical patient. At least six weeks later the same scenarios were presented in a new order, with vital signs information, and the participants again identified the interventions they would perform. The participants' estimations of the patients' blood pressures, as well as the frequencies with which 18 specific interventions were performed, were compared for the no-vital signs and the vital signs groups using chi-square of Fisher's exact test, with an alpha value of 0.05 considered significant.

RESULTS

Fourteen EMT-Ps and 16 EMT-Is completed both the no-vital signs and vital signs portions of the study, for a total of 1,160 hypothetical patient encounters. When vital signs were given, the EMT-Is were more likely to apply a cardiac monitor (65.2% vs 80.1%, p = 0.000), more likely to start at least one intravenous (i.v.) line (82.1% vs 87.8%, p = 0.038), and more likely to administer a medication (1.3% vs 5.6%, p = 0.003). The EMT-Ps were also more likely to apply a cardiac monitor (84.4% vs 90.3%, p = 0.041), more likely to run an i.v. at a "wide open" rate (9.5% vs 19.0%, p = 0.004), and less likely to identify patients as being hypotensive (39.9% vs 26.4%, p = 0.004).

CONCLUSION

The presence or absence of vital signs information does influence some of the patient care decisions of EMS providers; however, the clinical implications of these decisions are unclear. Further studies are needed to determine whether ALS providers can adequately manage actual patients without obtaining vital signs.

Potential time savings by prehospital administration of activated charcoal

OBJECTIVE

Activated charcoal (AC) has been proven useful in many toxic ingestions. Theoretically, administration of AC in the prehospital environment could save valuable time in the treatment of patients who have sustained potentially toxic oral ingestions. The purpose of this study was to determine the frequency of prehospital AC administration and to identify time savings that could potentially result from field AC administration.

METHODS

Adult patients with a chief complaint of toxic ingestion who had complete emergency medical services (EMS) and emergency department (ED) records and no medical treatment (gastric emptying, AC administration) prior to EMS arrival were eligible for inclusion. Data obtained from EMS and ED records included time of EMS departure from the scene, time of EMS arrival at the ED, and time of administration of AC in the ED. Since most EMS agencies in this system do not insert gastric tubes, patients requiring gastric tube placement for administration of AC were excluded.

RESULTS

Twenty-nine of 117 (24.8%) adult patients received oral AC with no other intervention. None of the 117 patients received AC in the prehospital setting. The EMS transport time for these patients ranged from 5 to 43 minutes (mean 16.2 +/- 9.7 minutes). The delay from ED arrival to AC administration ranged from 5 to 94 minutes (mean 48.8 +/- 24.1 minutes), and was more than 60 minutes for 14 (48.2%) of the patients. The total time interval from scene departure to ED AC administration ranged from 17 to 111 minutes (mean 65.0 +/- 25.9 minutes).

CONCLUSIONS

In a selected subset of patients who tolerate oral AC, prehospital administration of AC could result in earlier and potentially more efficacious AC therapy. Prospective study of the benefits and feasibility of prehospital AC administration is indicated.

Assessment of breath sounds during ambulance transport

STUDY OBJECTIVE

To determine whether the environment of a moving ambulance affects the ability of our-of-hospital care providers to auscultate breath sounds.

METHODS

Out-of-hospital care providers assessed breath sounds with a previously described breath-sounds model in a quiet environment (control) and in a moving ambulance. The setting was a nonurban emergency medical services system and an interhospital transport agency based at a 600-plus-bed tertiary care center. The participants were physicians, transport nurses, and advanced life support EMS providers routinely involved in the emergency out-of-hospital treatment and transportation of the ill and injured. The accuracy with which participants identified the presence or absence of breath sounds in the two environments was compared with the use of the chi 2 test, with the alpha-value set at .05.

RESULTS

The accuracy of breath-sounds assessment in the control environment was 96% (251 of 260); the sensitivity was 96% and the specificity 97%. The accuracy of breath-sounds assessment in the experimental environment was 54% (140 of 260); the sensitivity was .09% and the specificity 98%. Participants were significantly less likely to hear breath sounds in the moving ambulance than in the quiet room (P < .001).

CONCLUSION

Assessment of breath sounds is hampered by the environment of a moving ambulance.

Do pulse checks cause a significant delay in the initial defibrillation sequence?

This study was undertaken to determine if checking for a pulse between initial defibrillations causes a clinically significant delay in the administration of the defibrillations. Ten emergency department nurses and 10 emergency medicine resident physicians were timed delivering three successive defibrillations (200, 300 and 360 J) to a manikin under three randomly assigned scenarios: (1) without pulse checks; (2) with pulse checks performed by an assistant; and (3) with pulse checks performed by the participant. All participants performed the three defibrillation scenarios using three different models of defibrillators. Repeated measures analysis of variance was used to compare mean defibrillation times for the three scenarios. The mean time was 20.4 +/- 1.0 s for defibrillation without pulse checks; 20.2 +/- 1.2 s with pulse checks by an assistant and 22.0 +/- 2.0 s with pulse checks by the participant. There was a statistically significant difference between no pulse checks and pulse checks by the participant. No statistically significant difference was noted between no pulse checks and pulse checks by an assistant. We conclude that checking for a pulse does cause a statistically significant delay in the administration of defibrillations. This difference, however, is not likely to be clinically relevant.

Comparison of staples vs suturing for securing central venous catheters

OBJECTIVE

To determine whether skin staples can be used to secure central venous catheters as effectively as does suturing.

METHODS

A prospective, randomized trial of techniques to secure a central venous catheter was performed in a medical school human anatomy laboratory using human cadavers. Central lines were secured to the upper left thorax using either standard suture material (000 silk) or skin staples (5.7 mm x 3.8 mm). Once secured, an upward force was applied to the hub of the catheter perpendicular to the skin. The amount of force needed to break the catheter hub free of the skin was measured in kg. A total of 10 measurements were made for each of 3 methods for securing the catheters (2 sutures, 2 staples, 4 staples). In addition, the site of catheter breakage was recorded.

RESULTS

Those catheter hubs secured by 2 sutures required a mean force of 3.1 +/- 0.5 kg to cause breakage, and the break always occurred at the suture. Those hubs secured by 2 staples gave way at 3.0 +/- 0.3 kg (p = NS), while those secured with 4 staples gave way at 4.5 +/- 1.4 kg (p < 0.05). Although 1 hub did break, in all other stapled cases, the break occurred at the staple.

CONCLUSIONS

Based on this cadaver model, use of staples appears to be as effective as suturing for securing central venous catheters. Further studies of safety and time for placement are needed.

EMS knowledge and skills in rural North Carolina: a comparison with the National EMS Education and Practice Blueprint

INTRODUCTION

Many state and local emergency medical services (EMS) systems may wish to modify provider levels and their scope of practice to align their systems with the recommendations of the National Emergency Medical Services Education and Practice Blueprint. To determine any changes that may be needed in a typical EMS system, the knowledge and skills of EMS providers in one rural area of North Carolina were compared with the knowledge and skills recommended in the National Emergency Medical Services Education and Practice Blueprint.

METHODS

A survey listing 175 items of patient care-oriented knowledge and skills described in the National Emergency Medical Services Education and Practice Blueprint was developed. EMS providers from five rural eastern North Carolina counties were asked to identify on the survey those items of knowledge and skills they believed they possessed. The skills and knowledge selected by the respondents at the five different North Carolina levels of certification were compared with the knowledge and skills listed for comparable provider levels delineated by the National Emergency Medical Services Education and Practice Blueprint. The proportions of the recommended skills reported to be possessed by the respondents were compared to determine which North Carolina certification levels best correlate with the Blueprint.

RESULTS

One hundred forty-five EMS providers completed the survey. The proportion of recommended skills and knowledge reported to be possessed by Emergency Medical Technicians (EMTs) ranked significantly lower than did the skills and knowledge reported to be possessed by respondents at other levels in five of the 10 Blueprint elements. The proportion of recommended skills and knowledge reported to be possessed by EMT-Defibrillator-level personnel ranked lower than did those reported to be possessed by respondents at other levels in seven of the 10 Blueprint elements. The proportion of recommended skills and knowledge reported to be possessed by EMT-Intermediates ranked lower than did those reported to be possessed by respondents at other levels in nine of the 10 Blueprint elements. The proportion of recommended skills and knowledge reported to be possessed by EMT-Advanced Intermediates ranked lower than were the skills and knowledge reported to be possessed by respondents at other levels in two of the 10 Blueprint elements. Finally, the proportion of recommended skills and knowledge reported to be possessed by EMT-Paramedics ranked lower than were those reported to be possessed by respondents at other levels in one of the 10 Blueprint elements.

CONCLUSION

In North Carolina, combining the EMT and EMT-Defibrillator levels and eliminating the EMT-Intermediate level would create three levels of certification, which would be more consistent with levels recommended by the Blueprint. The results of this study should be considered in any effort to revise the levels of EMS certification in North Carolina and in planning the training curricula for bridging those levels. Other states may require similar action to align with the National Emergency Medical Services Education and Practice Blueprint.

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

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Serum estradiol in the differential diagnosis of ectopic pregnancy

In a prospective study using a cutoff value of 140 pg/mL, serum estradiol 17-beta assay had a sensitivity of 83% and a specificity of 100% in differentiating ectopic pregnancy (6 patients) from normal pregnancy with threatened abortion proceeding to viability (7 patients). In differentiating threatened abortion from spontaneous abortion (9 patients), the estradiol assay had a sensitivity of 88.9% and a specificity of 100%. All but one of the patients with ectopic pregnancy had estradiol levels below the cutoff value of 140 pg/mL, as did all but one of the patients who had spontaneous abortion. All the patients who had threatened abortion that progressed to viability had values well above the cutoff level. The mean estradiol values for the viable pregnancy group were significantly different from those of the other two groups. These data suggest that, at the institution where this study was done, serum estradiol determinations may be of value in the differentiation of both ectopic pregnancy and spontaneous abortion from threatened abortion but appears to be of very limited usefulness in distinguishing ectopic pregnancy from spontaneous abortion. The validity of these conclusions is limited by the small number of subjects. Further studies comprising greater numbers of subjects are needed.

Does ambulance crew size affect on-scene time or number of prehospital interventions?

INTRODUCTION

While large cities typically staff ambulances with two emergency medical services (EMS) professionals, some EMS agencies use three people for ambulance crews. The Greenville, North Carolina, EMS agency converted from three-person to two-person EMS crews in July 1993. There are no published reports investigating the best crew size for out-of-hospital emergency care.

HYPOTHESIS

Two-person EMS crews perform the same number and types of interventions as three-person EMS crews. Two-person EMS crews do not have longer on-scene times than do three-person EMS crews.

METHODS

Data for the two most common advanced life support calls in this system--seizures and chest pains--were collected for the months of June and August 1993. Three-person EMS crews responded to both types of calls in June. In August, two-person EMS crews responded to seizure calls; two-person EMS crews accompanied by a fire department engine (pumper) with additional manpower responded to chest pain calls. The frequency of specific interventions, number of total interventions, and scene times for the August calls were compared to their historical control groups, the June calls.

RESULTS

One hundred twenty-six patient contacts were included in the study. There were no significant differences in total number or types of procedures performed for the two patient groups. Mean on-scene time for patients with seizures was 11.0 +/- 4.2 minutes for three-person crews and 19.4 +/- 8.3 minutes for two-person crews (p < 0.001). Mean on-scene time for patients with chest pain was 13.6 +/- 4.9 minutes for three-person crews, and 15.4 +/- 3.2 minutes for two-person crews assisted by fire department personnel (p > 0.05).

CONCLUSION

Two-person EMS crews perform the same number of procedures as do three-person EMS crews. However, without the assistance of additional responders, two-person EMS crews may have statistically significantly longer on-scene times than three-person EMS crews.

Does the ambulance environment adversely affect the ability to perform oral endotracheal intubation?

OBJECTIVE

Oral endotracheal intubation (ETI) is the preferred method of controlling the airway in critically ill or injured patients. It was postulated that time could be saved if intubation was performed in the ambulance en route to the hospital. This study was designed to determine whether the ambulance environment adversely affected the ability of emergency medical technicians at the advanced-intermediate level (EMT-AI) to perform oral ETI.

HYPOTHESIS

The restrictive environment of a moving ambulance would affect adversely the ability of EMT-AIs to perform ETI compared with a controlled setting. This would result in a significant increase in the time necessary to perform ETI in the ambulance compared with a controlled setting not complicated by restrictive space and motion.

METHODS

Twenty on-duty EMT-AIs were recruited to volunteer for this prospective, nonrandomized, nonblinded trial. All participants performed three consecutive oral ETIs on an airway mannequin in two settings: 1) in the back of a moving ambulance; and 2) on a table in the rescue squad station. Of the participants, 10 performed the intubations in the ambulance first; the remainder performed the intubations at the station first. Time for intubation with the mannequin was recorded by stopwatch. The mean times for intubation in both settings were compared by Student's t-test (p < 0.05).

RESULTS

All intubation attempts were successful. The mean time for intubation in the station was 13.0 +/- 3.4 seconds. The mean time in the ambulance setting was 13.2 +/- 5.3 seconds. There was no significant difference between the intubation times in the two settings (p = 0.88).

CONCLUSION

The environment of a moving ambulance does not appear to hinder the ability of EMT-AIs to perform oral ETI in a laboratory setting with a mannequin model.

Can prehospital personnel detect hypoxemia without the aid of pulse oximeters?

Although pulse oximeters have been proven accurate in the prehospital environment, they have not been proven to be necessary. This study was undertaken to determine if emergency medical services (EMS) providers can identify hypoxemia without pulse oximetry. An oximeter was placed at the ambulance entrance to the emergency department (ED), and EMS personnel obtained saturation levels on all patients on arrival. Hypoxemia was defined as a saturation level of 95% or less. The hypoxemia was classified as "recognized" if the patient received aggressive intervention and "unrecognized" if the patient did not. One hundred eighty patients were enrolled in the study; 30 had a saturation level of 95% or less. Twenty-seven (90%) of those patients had "unrecognized" hypoxemia. Twenty-three (85.2%) of the 27 patients with "unrecognized" hypoxemia did not complain of respiratory distress. Thus, there are patients whose hypoxemia is unrecognized by EMS providers, and this occurs most frequently in patients who do not complain of respiratory distress.

Mistaken identity: the effect of badges on EMT recognition

INTRODUCTION

Many emergency medical services (EMS) providers wear badges with their uniforms. This study was undertaken to determine whether emergency medical technicians (EMTs) who wear badges with their uniforms are more likely to be mistaken for law enforcement personnel than are those who do not wear badges.

HYPOTHESIS

Emergency medical services providers who wear badges are more likely to be mistaken for law enforcement personnel than are those who do not wear badges.

METHODS

High school students, college students, civic organizations, and church groups were shown slides of different uniforms and badges/insignia and asked to identify the person portrayed. Responses were categorized as "EMS," "law enforcement," or "other." Frequency of responses for each uniform and insignia were compared with chi-square analysis.

RESULTS

Fifty-nine percent of the uniforms with badges were identified as law enforcement personnel. Only 5.5% of the uniforms with badges were identified as "EMS," compared with 74% of the uniforms with a Star of Life (p < 0.001).

CONCLUSION

Individuals wearing uniforms with badges are more likely to be identified as law enforcement personnel than are EMS personnel. Emergency medical services providers who do not wish to be mistaken for law enforcement personnel should wear the Star of Life, not a badge, with their uniform.

Do pulse checks delay semiautomatic defibrillation by EMT-defibrillators?

Advanced cardiac life support (ACLS) guidelines from the American Heart Association (AHA) now recommend not checking for a pulse between the initial three defibrillations for pulseless patients in ventricular tachycardia or fibrillation. The AHA asserts that checking for a pulse needlessly delays defibrillation. This study was undertaken to determine if pulse checks delay defibrillation by EMT-Defibrillators (EMT-Ds) using a semiautomatic defibrillator (SAED). Twenty-seven EMT-Ds demonstrated delivery of three successive defibrillations during two test scenarios: once with and once without pulse checks after the first and second defibrillations. The time from the first to third defibrillation was recorded. The mean time to deliver the defibrillations was 60.2 +/- 6.2 seconds with pulse checks and 57.5 +/- 4.6 seconds without pulse checks. The difference, 2.7 +/- 5.9 seconds, was statistically significant (P = 0.026). Pulse checks by EMT-Ds do delay administration of defibrillations, but consideration should be given to reinstating pulse checks as a part of the AHA guidelines, since this delay is of questionable clinical significance.

Is ambulance transport time with lights and siren faster than that without?

STUDY OBJECTIVE

To determine whether ambulance transport time from the scene to the emergency department is faster with warning lights and siren than that without.

DESIGN

In a convenience sample, transport times and routes of ambulances using lights and sirens were recorded by an observer. The time also was recorded by a paramedic who drove an ambulance without lights and siren over identical routes during simulated transports at the same time of day and on the same day of the week as the corresponding lights-and-siren transport.

SETTING

An emergency medical service system in a city with a population of 46,000.

PARTICIPANTS

Emergency medical technicians and paramedics.

RESULTS

Fifty transport times with lights and siren averaged 43.5 seconds faster than the transport times without lights and siren [t = 4.21, P = .0001].

CONCLUSION

In this setting, the 43.5-second mean time savings does not warrant the use of lights and siren during ambulance transport, except in rare situations or clinical circumstances.

Prehospital blood pressures: inaccuracies caused by ambulance noise?

Blood pressure measurements in a moving ambulance can be difficult to obtain. Sirens, engine noise, and road noise can all interfere with the accurate detection of a patient's blood pressure. This study was undertaken to determine the influence of ambulance noise and vibration on auscultated blood pressures. A model was developed that used dynamic pressures to simulate systolic Korotkoff sounds. Forty-nine emergency personnel were asked to obtain blood pressures using the model in both a quiet environment and in a moving ambulance. A total of 485 blood pressure measurements were obtained. Systolic pressures were randomized to two settings: 76 mm Hg and 138 mm Hg. Stationary readings were compared with moving readings using analysis of variance for repeated measures. Systolic blood pressure measurements obtained in the quiet environment averaged 133 +/- 5 mm Hg at the high setting, and 45 +/- 6 mm Hg at the low setting. Systolic blood pressure measurements obtained in a moving ambulance averaged 86 +/- 7 mm Hg at the high setting, and 41 +/- 7 mm Hg at the low setting. The average differences between quiet and moving measurements were 47 mm Hg at the "high" setting (P < .01) and 4 mm Hg at the "low" setting (P > .01). At physiological levels, blood pressures obtained in moving ambulances differ significantly from those obtained in a quiet environment, which may be caused by road noise and ambulance motion.

Public perceptions of a rural emergency medical services system

INTRODUCTION

To determine the awareness of citizens and physicians concerning the capabilities of a rural emergency medical services (EMS) system.

HYPOTHESIS

Citizens and physicians are unaware of the capabilities of the EMS system.

METHODS

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.

RESULTS

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).

CONCLUSION

This study indicates that both physicians and the lay public have little understanding of the capabilities of their EMS system.

Adverse lighting condition effects on the assessment of capillary refill

In 1989, Champion et al recommended revising the Trauma Score to exclude capillary refill because it is "difficult to assess at night. . . ." However, a literature search produced no studies evaluating the effect of lighting conditions on the assessment of capillary refill. This study was undertaken to determine if any such effect exists. Three hundred nine participants at an emergency medical services (EMS) seminar were asked to assess each others' capillary refill in both light and dark environments. The participants were nurses, emergency medical technicians (EMTs), and paramedics who had been instructed in the assessment of capillary refill. In daylight conditions (partly cloudy day, lux meter = 15 to 16), capillary refill was reported as normal in 94.2% of the participants, delayed in 1.9% of the participants, and undetected in 3.9% of the participants. In dark conditions (moonlight or street lamp, lux meter = 4 to 6), capillary refill was reported as normal in 31.7% of the participants, delayed in 1.6% of the participants, and undetected in 66.7% of the participants. chi 2 analysis demonstrated a statistically significant difference between capillary refill assessment in light versus dark environments (P < .001).

Study of the teratogenic potential of FD & C Yellow No. 5 when given by gavage to rats

FD & C Yellow No. 5 (tartrazine) was given to Osborne-Mendel rats by gavage at dose levels of 0, 60, 100, 200, 400, 600 or 1000 mg/kg body weight/day on days 0-19 of gestation. No maternal or developmental toxicity was observed when the rats were killed on day 20. The mean daily food consumption for the entire period of gestation was significantly greater in the females given 1000 mg/kg body weight/day than in the controls, but maternal body-weight gain was not affected. No dose-related effects were observed in implantations, foetal viability or external foetal development. Foetal skeletal and visceral development was similar among foetuses from all groups. At the doses given, FD & C Yellow No. 5 was neither toxic nor teratogenic.