P REHOSPITAL E MERGENCY C ARE , 6 TH E DITION

Abstract

Background. Traumatic brain injury (TBI) represents a serious subset of injuries among persons in the United States, and prehospital care of these injuries can mitigate both the morbidity and the mortality in patients who suffer from these injuries. Guidelines for triage of injured patients have been set forth by the American College of Surgeons Committee on Trauma (ACS-COT) in cooperation with the Centers for Disease Control and Prevention (CDC). These guidelines include physiologic criteria, such as the Glasgow Coma Scale (GCS) score, systolic blood pressure, and respiratory rate, which should be used in determining triage of an injured patient. Objectives. This study examined the numbers of visits at level I and II trauma centers by patients with a diagnosed TBI to determine the prevalence of those meeting physiologic criteria from the ACS-COT/CDC guidelines and to determine the extent of mortality among this patient population. Methods. The data for this study were taken from the 2007 National Trauma Data Bank (NTDB) National Sample Program (NSP). This data set is a nationally representative sample of visits to level I and II trauma centers across the United States and is funded by the American College of Surgeons. Estimates of demographic characteristics, physiologic measures, and death were made for this study population using both chi-square analyses and adjusted logistic regression modeling. Results. The analyses demonstrated that although many people who sustain a TBI and were taken to a level I or II trauma center did not meet the physiologic criteria, those who did meet the physiologic criteria had significantly higher odds of death than those who did not meet the criteria. After controlling for age, gender, race, Injury Severity Score (ISS), and length of stay in the hospital, persons who had a GCS score ≤13 were 17 times more likely to die than TBI patients who had a higher GCS score (odds ratio [OR] 17.4; 95% confidence interval [CI] 10.7–28.3). Other physiologic criteria also demonstrated significant odds of death. Conclusions. These findings support the validity of the ACS-COT/CDC physiologic criteria in this population and stress the importance of prehospital triage of patients with TBI in the hopes of reducing both the morbidity and the mortality resulting from this injury.     

T ACTICAL E MERGENCY C ARE,M ILITARY AND O PERATIONAL O UT-OF -H OSPITAL M EDICINE

To improve the outcomes of stroke patients, public awareness of stroke must be increased and emergency medical services (EMS) response to stroke calls optimized. Rapid response to stroke is key, as emphasized in the American Stroke Association's “Stroke Chain of Survival,” which consists of four components—rapid recognition of and reaction to stroke warning signs through immediate use of the 9-1-1 system; rapid EMS assessment; priority transport with prenotification of the receiving hospital; and rapid and accurate diagnosis and treatment at the hospital. Neither the risk factors for stroke nor the most common warning signs are adequately known to the public in general, and in particular, to the groups at highest risk for stroke. Effective education through mass media and health care professionals is paramount in increasing the public's awareness of stroke. Whether tools to aid dispatchers and paramedics in stroke diagnosis, assessment, and management can improve stroke patients' outcomes requires further study, as does the value of designated stroke centers. Overall, according stroke the same urgency as acute myocardial infarction, from both the public and the prehospital provider perspectives, might improve stroke patient outcomes.     

U SE OF E MERGENCY M EDICAL S ERVICES BY C HILDREN WITH S PECIAL H EALTH C ARE N EEDS

Objective. This study describes emergency medical services (EMS) responses for children with special health care needs (CSHCN) in an urban area over a one-year period. Methods. A prospective surveillance system was established to identify EMS responses for children, 21 years of age or younger, with a congenital or acquired condition or a chronic physical or mental illness. Responses related to the special health care needs of the child were compared with unrelated responses. Results. During a one-year period, 924 responses were identified. Fewer than half of the responses were related to the child's special health care need. Younger children were significantly more likely to have a response related to their special needs than older children. Among related responses, seizure disorder was the most common diagnosis, while asthma was more common for unrelated responses. Almost 58% of the responses resulted in transport of the child to a hospital. Conclusions. Emergency medical services responses related to a child's special health care needs differ from unrelated responses. The most common special health care needs of children did not require treatment beyond the prehospital care provider's usual standard of care. These results are relevant for communities providing EMS services for CSHCN.     

T HE P RACTICE OF C LINICAL E CHOCARDIOGRAPHY,S ECOND E DITION

Abstract

Background. Multiple studies have demonstrated varying rates of successful endotracheal intubation (ETI). Until the application of video laryngoscopy, little information regarding prehospital intubation could be analyzed objectively by individuals other than the provider performing the ETI. Objective. To evaluate the association of variables recorded during video laryngoscopy and successful ETI attempts, defined as placing the endotracheal tube in the trachea. Methods. We retrospectively reviewed intubations performed by a single helicopter emergency medical service (HEMS) using a video larygoscope from March 1, 2010, to October 1, 2010. All videos were de-identified and analyzed by a single researcher. Time intervals (e.g., attempt time) and intubation process variables (e.g., Cormack-Lehane [C-L] view) were abstracted from all videos. Time intervals were begun when the laryngoscope blade passed the lips and entered the oral cavity (entry). We describe variables using means and standard deviations (continuous), medians with interquartile ranges (ordinal), and percentages with 95% confidence intervals (categorical). We then looked at univariate associations between these variables and ETI success using logistic regression. Results. We recorded 116 intubations during the study period. Twenty-nine recordings were either incomplete (n = 26) or of insufficient quality for analysis (n = 3). The remaining 87 videos represented 87 different patients with a total of 102 attempts at laryngoscopy. Thirty-six providers performed 64 cases, with the majority of providers (n = 21) performing only one intubation. The first-pass success rate in this series was 76% (n = 66), with 98% success within three attempts. Successful ETI attempts had lower entry–to–percentage of glottic opening (POGO) times (16.6 sec vs. 32.1 sec, p = 0.013), entry–to–first view of the endotracheal tube or entry-to-tube times (17.6 sec vs. 27.4 sec, p = 0.04), higher POGO scores (76 vs. 39, p < 0.001), and a lower C-L view (one vs. three, p < 0.001). Recognized esophageal intubation was more likely to occur during unsuccessful ETI attempts (43% vs. 8%, p < 0.001). Conclusion. Video laryngoscopy can measure multiple components of ETI performance. Successful ETI attempts have significantly shorter entry-to-POGO times and entry-to-tube times, obtain better views of the glottic opening (POGO and C-L view), and have a lower incidence of recognized esophageal intubation.     

C ARDIAC A RREST M ANAGEMENT

Approximately 1,000 people in the United States suffer cardiac arrest each day, most often as a complication of acute myocardial infarction (AMI) with accompanying ventricular fibrillation or unstable ventricular tachycardia. Increasing the number of patients who survive cardiac arrest and minimizing the clinical sequelae associated with cardiac arrest in those who do survive are the objectives of emergency medical personnel. In 1990, the American Heart Association (AHA) suggested the chain of survival concept, with four links—early access, cardiopulmonary resuscitation (CPR), defibrillation, and advanced care—as the way to approach cardiac arrest. The recently published International Resuscitation Guidelines 2000 of the AHA have addressed advances in our understanding of the chain of survival. While the chain of survival concept has withstood a decade of scrutiny, there are only a few scientifically rigorous research studies that support changes in prehospital patient care. Additional research efforts carried out in the prehospital setting are needed to support the concepts included in the chain of survival for cardiac arrest patients. Participants at the second Turtle Creek Conference, a meeting of experts in the field of emergency medicine held in Dallas, Texas, on March 29–31, 2000, discussed these and other issues associated with prehospital emergency care in the cardiac arrest patient. This paper addresses a number of the issues associated with each of the links of the chain of survival, the evidence that exists, and what should be done to achieve the clinical evidence needed for true clinical significance. Also included in this paper are the consensus statements developed from small discussion groups held after the main presentation. These comments provide another perspective to the problems and to possible approaches to deal with them.     

W EAPONS OF M ASS D ESTRUCTION : E MERGENCY C ARE

Objectives. The authors investigated the dying patterns, and cause and preventability of deaths in a major earthquake disaster, and estimated the cost needed to enhance emergency medical services (EMS) response to prevent “unnecessary” deaths. Methods. The authors reviewed autopsy data in the Hanshin-Awaji (Kobe) earthquake of 1995. A survival analysis was performed to determine the time course and pattern of dying of these deaths. A cost analysis to estimate acceptable cost for EMS to reduce fatalities was also performed. Potentially salvageable life-years based on expected life-years among fatalities were calculated and used to simulate an acceptable cost for an enhanced EMS disaster response. Results. The authors analyzed 5,411 fatalities. More than 80% of these patients died within three hours. There were statistically significant differences in survival/dying patterns among causes of death. Thirteen percent of victims experienced a protracted death, which could have been prevented with earlier medical or surgical intervention. The monetary cost of these lost lives was estimated at approximately $600 million US. Conclusions. Survival analysis revealed a significant population of potentially salvageable patients if more timely and appropriate medical intervention had been available immediately after the earthquake. Based on our cost analysis, and assuming a 1% annual probability of an earthquake and a 30% enhanced lifesaving capability of the EMS effort, approximately $2 million annually could be a reasonable expenditure to achieve the goal of reducing preventable deaths in disasters.     

D YSRHYTHMIA R ECOGNITION AND M ANAGEMENT,T HIRD E DITION

Abstract

Objectives. To evaluate whether chest compressions affect the time taken for intubation (TTI) using the Macintosh laryngoscope and two portable video laryngoscopes (VLs) (GlideScope Ranger and Airway Scope) when used by novice prehospital caregivers, and to compare the TTIs and rates of successful intubation among the three laryngoscopes with and without chest compressions in a manikin model. Methods. This was a pilot randomized crossover study. Twenty paramedic students and paramedics who had no clinical experience with tracheal intubation and had never used any of two VLs participated in the study. After a one-hour training session for the VLs, participants performed intubations on a Laerdal Resusci Anne Simulator placed on the floor. Each paramedic used all three laryngoscopes, with the order of usage being randomly assigned. The TTIs and rates of successful intubation among the three laryngoscopes, with and without ongoing chest compressions, were compared. Results. The difference between the TTIs using each laryngoscope with and without chest compressions was not significant (Macintosh: 2.99 sec, p == 0.06; GlideScope Ranger: 2.04 sec, p == 0.11; and Airway Scope: 0.91 sec, p == 0.10). The median TTI using the Airway Scope (15.46 sec) was significantly shorter than those for the Macintosh (24.14 sec) and the GlideScope Ranger (24.12 sec) during chest compressions (p == 0.028 and p == 0.004, respectively). There were no significant differences in the rates of successful intubation among the three laryngoscopes on each condition (without chest compressions, p == 0.15; with chest compressions, p == 0.27), but the cumulative success rates related to the TTI were significantly greater with the Airway Scope than with the other devices in both conditions. Conclusion. In this pilot study, chest compressions did not significantly affect the TTI using the Macintosh laryngoscope and two portable VLs when used by novice prehospital caregivers in the manikin model on the floor. Considering the fairly short training time, two portable VLs may be potentially useful adjuncts for tracheal intubation during chest compressions for novice prehospital caregivers. Further studies are required to validate whether these findings are clinically relevant.     

F2M—1型心肺复苏器抢救心脏骤停患者的临床观察

目的：观察Ｆ２Ｍ１型心肺复苏器抢救心脏骤停患者的临床应用价值。方法：根据胸泵原理，利用自行研制的Ｆ２Ｍ１型心肺复苏器与徒手胸外心脏按压相比较，用于抢救９例心脏骤停患者，观察其血压、潮气量及心电图变化。结果：Ｆ２Ｍ１型心肺复苏器与徒手按压时患者收缩压（分别为１５．１±３．０ｋＰａ和５．７±１．６ｋＰａ，１ｋＰａ＝７．５ｍｍＨｇ）比较，差异非常显著（Ｐ＜０．０１），舒张压（分别为７．０±２．５ｋＰａ和１．８±０．９ｋＰａ）差异极显著（Ｐ＜０．００１）。不同部位进行人工通气的潮气量对比，Ｆ２Ｍ１型心肺复苏器潮气量大于徒手按压法，尤以按压剑突下及上腹部潮气量增加最为显著。心电图观察对比，应用Ｆ２Ｍ１型心肺复苏器较徒手按压有利于室性自主心律和窦性心律的恢复。结论：Ｆ２Ｍ１型心肺复苏器显著提高了心脏骤停患者的血压、潮气量和窦性心律的恢复，有利于急症患者的抢救。     

C OMPARISON OF C APILLARY AND V ENOUS G LUCOSE M EASUREMENTS IN H EALTHY V OLUNTEERS

Background. Out-of-hospital (OOH) emergency personnel measure serum glucose in order to determine the need for dextrose therapy. Most devices that measure serum glucose are designed to use capillary blood obtained from a finger puncture. However, OOH emergency personnel often use venous blood obtained during intravenous line (IV) placement to determine serum glucose. Objective. To compare capillary and venous glucose measurements. Methods. This prospective study used healthy, non-fasting volunteers. Simultaneous venous and capillary blood samples were obtained from each subject. Glucose levels were measured using a glucometer designed for capillary samples. The capillary and venous measurements were compared using a Pearson correlation coefficient. Power analysis revealed that the study had the ability to detect a difference of 15?mg/dL. Results. Ninety-seven volunteers (56 males, 41 females) with a mean age of 37 ± 11.9 years were enrolled. The mean capillary and venous glucose values were 104.5 ± 20.7?mg/dL and 109.7 ± 22.4?mg/dL, respectively. The Pearson correlation coefficient was 0.24. Conclusions. The correlation between venous and capillary blood glucose measurements is relatively poor in this group of healthy volunteers. Further research must be conducted on patients at risk for abnormal blood glucose.     

H EALTH C ARE F ACILITY P REPARATION FOR W EAPONS OF M ASS D ESTRUCTION

Weapons of mass destruction (WMD) are a threat that all health care facilities must be prepared for. Every health care facility is a vital part of the community response system and must be ready to respond. A terrorist attack using WMD can occur in any location, urban or rural. Private vehicles or buses may transport the majority of patients, with only a small percentage arriving by emergency medical services. Most will go to the hospitals closest to the incident, even if this results in overcrowding. Others will go directly to their private physicians' offices or primary hospitals, even if these facilities are not part of the local disaster plan. Most of these victims will not be decontaminated before arrival. If a hospital allows any of these patients in, the staff may become ill from the toxic exposure and the facility may require closure for decontamination. Since the risk is universal, all health care facilities must plan for the care of victims of a WMD incident. They must plan for communications that allow local government to transmit alerts regarding the emergency. Health care facilities must also communicate their status and emergency needs to local officials during the emergency. They must be prepared to establish a single entry control point and attempt to secure all other entrances. They must be able to establish a patient decontamination team from on-duty staff with only a few minutes' notice at any time of the day or night.     

A N E MERGENCY M EDICAL S ERVICES P ROGRAM OF A LTERNATE D ESTINATION OF P ATIENT C ARE

Objective: The emergency department (ED) is ideally reserved for urgent health needs. The ED, however, is often the site of care for nonurgent conditions. The authors investigated whether emergency medical technicians could decrease ED use by patients with nonurgent concerns who use 911 by appropriately identifying and triaging them to alternate care destinations. Methods: From August 2000 through January 2001, two King County fire-based emergency medical services (EMS) agencies participated in an alternate care destination program for patients with specific low-acuity diagnosis codes (intervention group). Eligible patients were offered care at a clinic-based destination as an alternate to the ED (n = 1,016). The frequency of the destination of care (ED, clinic, or home) for the intervention group was compared with a matched control group that was comprised of a preintervention historical cohort of EMS encounters from the same two fire-based agencies and with the same acuity and diagnosis criteria and seasonal interval (n = 2,617). Results: Compared with the preintervention group, a smaller proportion of patients in the intervention group received care in the ED (44.6% vs. 51.8%, p = 0.001), while a greater proportion of patients in the intervention group received clinic care (8.0% vs. 4.5%, p = 0.001) or home care (no transport) (47.4 vs. 43.7%, p = 0.043). Results were comparable when adjusted for other patient characteristics. Similar relationships were not evident among nonparticipating King County EMS agencies. Based on physician review and patient interview, the alternate care intervention appeared to be safe and satisfactory. Conclusion: An EMS-based program may represent one approach to limiting nonurgent ED use.     

E MERGENCY P REPAREDNESS FOR C HILDREN WITH S PECIAL H EALTH C ARE N EEDS

Objective. To evaluate the change in nausea scales andincidence of vomiting with the use of ondansetron in the treatment of nausea andvomiting in the prehospital setting. Methods. Data were prospectively collected on all emergency medical service patients who received ondansetron for undifferentiated nausea andvomiting during a 6-month study period. Added outcome measures for this study were verbal quantitative (scale of 1–10) andqualitative “nausea scales,” incidence of vomiting prior to andafter administration of ondansetron, andadverse events. Patients who had this additional data collected andones who did not were compared. Changes in the “nausea scales” andincidence of vomiting before andafter administration andcorrelation among these measures were also compared. There was no control or placebo group. Results. Ondansetron was administered to 952 patients of 20,054 patients transported during this time period (5%); of these 472 had at least some of the outcome measures documented. There were minimal differences in the two cohorts; 198 patients had paired before andafter quantitative “nausea scales” documented: 7.6 ± 2.4 and4.6 ± 3.1, respectively (Δ = 2.9, 95% CI: 2.5–3.4); 447 patients had a qualitative change in nausea level documented: 0.4% “a lot worse,” 1.3% “a little worse,” 34% “unchanged,” 40% “a little better,” and25% “a lot better”; 187 patients had all three measures documented with a Pearson correlation coefficient of 0.63 between the change in the quantitative scale andthe qualitative scale (95% CI: 0.14–0.20, R 0.39). In 462 patients, vomiting decreased from 60% to 30% (Wilcoxon signed ranks test p < 0.001). The Pearson correlation coefficients for the change in vomiting incidence with the qualitative andquantitative “nausea scales” were poor: 0.012 (95% CI: ?0.015 to 0.039, R 0.00014) and0.051 (95% CI: ?0.032 to 0.118, R 0.00026), respectively. There were no reported adverse events. Conclusions. Ondansetron appears to be moderately effective in decreasing nausea andvomiting in undifferentiated prehospital patients. Additional controlled trials may be needed to compare it with other antiemetics.     

D ETERMINATION OF M EDICAL N ECESSITY FOR A IR AND C RITICAL C ARE M EDICAL T RANSPORTATION

Abstract

Objective. We aimed to assess the diagnostic accuracy of focused assessment with sonography for trauma (FAST) examinations when used by emergency medical technicians (EMTs) to detect the presence of free abdominal fluid. Methods. Six level 1 EMTs (similar to intermediate EMTs in the United States) who worked at a tertiary emergency department in Korea underwent an educational program consisting of two one-hour didactic lectures that included the principles of ultrasonography, the anatomy of the abdomen, and two hours of hands-on practice. After this educational session, the EMTs performed FAST examinations on a convenience sample of patients from July 1 to October 5, 2009. These patients also received an abdominal computed tomography (CT) scan regardless of their chief complaints. The CT findings served as the definitive standard and were interpreted routinely and independently by emergency radiologists who were blinded to the study protocol. In addition, the EMTs were blinded to the CT findings. A positive CT finding was defined as the presence of free fluid, as interpreted by the radiologist. The sensitivity, specificity, predictive values, and their 95% confidence intervals (CIs) were calculated. Informed consent was obtained from all participating patients. Results. Among the 1,060 eligible patients with abdominal CT scans, 403 patients were asked to participate in the study, and 240 patients agreed. Of these 240 patients, 80 (33.3%) had results showing the presence of free fluid. Fourteen patients had a significant amount of peritoneal cavity fluid, 15 had a moderate amount of peritoneal cavity fluid, and 51 had a minimal amount of peritoneal cavity fluid. Compared with the CT findings, the diagnostic performance of the FAST examination had a sensitivity of 61.3% (95% CI, 50.3%–71.2%), specificity of 96.3% (95% CI, 92.1%–98.3%), positive predictive value of 89.1% (95% CI, 77.0%–95.4%), and negative predictive value of 83.2% (95% CI, 76.9%–88.2%). For a significant or moderate amount of peritoneal cavity fluid, the sensitivity was considerably higher (86.2%). Conclusion. EMTs in Korea showed a high diagnostic performance that was comparable to that of surgeons and physicians when detecting peritoneal cavity free fluid in a Korean emergency department setting. The validity of FAST examinations in prehospital care situations should be investigated further.     

E ND - TIDAL C ARBON D IOXIDE M ONITORING IN THE P REHOSPITAL S ETTING

End-tidal carbon dioxide (ETCO₂) monitoring is an exciting technology and has the potential to become a very useful tool in the prehospital setting. It can be useful in verifying endotracheal tube position and during cardiopulmonary resuscitation in the field. Recent reports of misplaced endotracheal tubes in the prehospital setting make it important to ensure that paramedics learn correct techniques of endotracheal intubation, and that they verify tube placement with an ETCO₂ monitor. The new American Heart Association guidelines require secondary confirmation of proper tube placement in all patients by exhaled CO₂ immediately after intubation and during transport. This article covers the terminology, the basic physiology, the technology (both colorimetric detectors and infrared capnometers), and the clinical applications of ETCO₂ monitoring with special reference to the pediatric patient.     

EPO对心肺复苏后大鼠海马神经元的细胞凋亡、Bcl-2及Bax表达的影响

目的观察促红细胞生成素(EPO)在心肺复苏后对大鼠脑海马神经元细胞凋亡、Bcl-2和Bax表达的影响。方法雄性Wistar大鼠32只,随机分4组:正常对照组(A组)、假手术组(B组)、心肺复苏模型组(C组)、EPO干预组(D组)。C组、D组采用窒息的方法制作大鼠呼吸心跳骤停模型,后行心肺复苏治疗(CPR),D组CRP同时静脉给予EPO 3000U/kg;B组仅静脉给予等剂量生理盐水,4小时的脑海马组织,采用免疫组化法观察各组神经元细胞凋亡、Bcl-2及Bax的表达情况。结果光镜下A、B组未见凋亡细胞,C组可见较多凋亡细胞,D组凋亡细胞数少于C组(P0.01)。A、B组少量Bcl-2、Bax阳性细胞,C、D组Bcl-2、Bax阳性细胞数均高于A、B组(P0.01),D组Bcl-2阳性细胞数高于C组(P0.01),D组Bax阳性细胞数低于C组。结论心肺复苏后大鼠海马神经元的细胞凋亡明显增加,Bcl-2、Bax表达上调。EPO可抑制心肺复苏后海马神经元的细胞凋亡、上调Bcl-2表达同时下调Bax表达。