Prehospital Studies Research Articles

Military medical research in Britain and the USA: the challenge of informed consent

Military medical research requires informed consent from test subjects, which is difficult to obtain for deployed (in-theatre) or prehospital studies where patients are incapacitated and legal representatives are not available....

Utilizing Propensity Score Analyses in Prehospital Blood Product Transfusion Studies: Lessons Learned and Moving Toward Best Practice.

Recently, observational studies analyzing prehospital blood product transfusions (PHT) for trauma have become more widespread in both military and civilian communities. Due to these studies’ non-random treatment assignment, propensity score (PS) methodologies are often used to determine an intervention’s effectiveness. However, there are no guidelines on how to appropriately conduct PS analyses in prehospital studies. Such analyses are complicated when treatments are given in emergent settings as the ability to administer treatment early, often before hospital admission, can interfere with assumptions of PS modeling. This study conducts a systematic review of literature from military and civilian populations to assess current practice of PS methodology in PHT analyses. The decision-making process from the multicenter Prehospital Resuscitation on Helicopter Study (PROHS) is discussed and used as a motivating example. Results show that researchers often omit or incorrectly assess variable balance between treatment groups and include inappropriate variables in the propensity model. When used correctly, PS methodology is an effective statistical technique to show that aggressive en route resuscitation strategies, including PHT, can reduce mortality in individuals with severe trauma. This review provides guidelines for best practices in study design and analyses that will advance trauma care.

A novel rat model of orthopedic trauma for prehospital pain studies

Animal models of orthopedic trauma usually consist of tibia or femur fractures that require a post‐fracture fixation surgery. Such an approach compromises subsequent assessments of pain following orthopedic trauma. The goal of the current study was to establish a rat model of long bone fracture that needs no post‐trauma surgeries, thereby optimizing its utility for future studies especially with prehospital pain management. Orthopedic trauma, including soft tissue injury and fibula fracture, was performed on the right hindlimb in Sprague Dawley rats. Soft tissue injury was induced in anesthetized rats via clamping the retrofemoral tissue groups for 30 sec, followed by closed fibula fracture using a 15‐gauge needle. Thermal hyperalgesia (paw withdrawal time, PW, n = 24), mechanical allodynia (mechanical threshold, MT, n = 17), weight‐bearing ratio (right/left, WB, n = 12), and tail flick latency (n = 10) were determined before and 90 minutes after the injury. Rats were then treated with 5 mg/kg ketamine or vehicle (saline) through jugular catheters, and nociceptive measurements were repeated at 10, 40, 80, and 120 minutes after injection. Trauma had no effect on tail flick responses but decreased PW, MT, and WB (Table 1). Ketamine increased PW, WB, and tail flick latency mainly within the first 40 minutes following injection (Figure 1). As no post‐trauma surgery is required, our data suggest that this trauma model may be ideal for prehospital pain research. To our knowledge, this is the first study to show that 5 mg/kg of ketamine iv could be considered for instant analgesia in rats. Thermal hyperalgesia (PW), mechanical allodynia (MT), weight‐bearing ratio (WB), and tail flick response before and after trauma. PW (second) MT (gram) WB (right/left) Tail flick (second) Basal 11.3±0.5 40.5±1.5 1.0±0.1 5.6±0.2 Trauma 6.5±0.2* 31.7±2.3* 0.5±0.1* 5.6±0.1 P < 0.05 trauma vs. basal.

Erratum to: The effectiveness of apneic oxygenation during tracheal intubation in various clinical settings: a narrative review.

During the process of tracheal intubation, patients are apneic or hypoventilating and are at risk of becoming hypoxemic. This risk is especially high in patients with acute or chronic respiratory failure and accompanying compromised respiratory reserve. To address this concern, apneic oxygenation can be administered during tracheal intubation to aid in maintaining arterial oxygen saturation. The objective of this narrative review is to examine the utilization of apneic oxygenation within the operating room, intensive care unit (ICU), emergency department, and pre-hospital settings and to determine its efficacy compared with controls. For this narrative review, we obtained pertinent articles using MEDLINE® (1946 to April 2016), EMBASE™ (1974 to April 2016), Google Scholar, and manual searches. Apneic oxygenation was administered using various techniques, including the use of nasal prongs, nasopharyngeal or endotracheal catheters, or laryngoscopes. First, all 12 operating room studies showed that apneic oxygenation significantly prolonged the duration to, and incidence of, desaturation. Second, two of the five ICU studies showed a significantly smaller decline in oxygen saturation with apneic oxygenation, with three studies showing no statistically significant difference vs controls. Lastly, two emergency department or pre-hospital studies showed that the use of apneic oxygenation resulted in a significantly lower incidence of desaturation and smaller declines in oxygen saturation. Sixteen of the 19 studies showed that apneic oxygenation prolongs safe apneic time and reduces the incidence of arterial oxygen desaturation. Overall, studies in this review show that apneic oxygenation prolongs the time to oxygen desaturation during tracheal intubation. Nevertheless, the majority of the studies were small in size, and they neither measured nor were adequately powered to detect adverse respiratory events or other serious rare complications. Prolonged apneic oxygenation (with its consequent hypercarbia) can have risks and should be avoided in patients with conditions such as increased intracranial pressure, metabolic acidosis, hyperkalemia, and pulmonary hypertension.

Abstract WP257: Accuracy of Pre-enrollment Last Known Well Time in a Large Prehospital Stroke Clinical Trial

Background: Clinical trials of stroke therapies require accurate documentation of last known well time (LKWT) to account for injury accumulation prior to treatment start. For prehospital studies, this requirement is particularly challenging, as paramedic-determined and final-determined LKWTs in routine practice are concordant (within 15 mins) in only half of cases. We sought to determine the accuracy of LKWT obtained in the field by a two-tier enrollment system of study-trained paramedics and cellphone-connected physician-investigators. Methods: Paramedics screened consecutive transports for participation in the NIH Field Administration of Stroke Therapy-Magnesium (FAST-MAG) clinical trial. Paramedic screening criteria included LKWT <2 hours. Physician-investigators by cellphone confirmed or refined the LKWT after conversation with paramedics and patients or legally authorized representative. Prehospital LKWT was compared with post-arrival LKWT determined by trained study nurses after ED arrival by speaking with patients, family and other sources. We describe the number of enrollment calls with inaccurate LKWT at the paramedic-screening level and at the post paramedic plus physician-investigator telephone screening level. Results: A total of 4458 post-screening enrollment calls were made by paramedics from January 2005 to December 2012 of which 539 (12%) were determined by physician-instigators to have inaccurate LKWT leading to non-enrollment. Of the remaining 3919 calls, 1700 led to enrollments in the study and 2219 were not enrolled for a reason other than inaccurate LKWT. Among enrolled cases, exact congruence between prehospital and post-arrival LKWTs occurred 72% (n=1220), concordance within 15 minutes in 87%, within 30 minutes in 93%, and within 1 hour in 97%. Among enrolled cases, final-determined LKWT was within the study entry window of 2h in 96.3%. Conclusions: A 2-tiered system of paramedic screening followed by physician-investigator cellphone assessment led to high congruence between prehospital-determined and post-arrival-determined of LKWT. This system can be used in future trials of prehospital, paramedic-in initiated stroke therapy when accuracy of LKWT is important for intervention evaluation.

Abstract TP250: A Substantial Rate of Neurological and Non-Neurological Stroke Mimics Are Transported by Emergency Medical Services for Acute Stroke Evaluation

Introduction: The impact of prehospital triage of stroke mimics to designated stroke centers may be considerable, yet little information exists regarding stroke mimics in the prehospital setting. We aimed to describe the rate and clinical characteristics of neurological and non-neurological stroke mimics transported by Emergency Medical Services (EMS) to the Emergency Department (ED) for acute stroke evaluation. Methods: A retrospective, cross-sectional, observational analysis of a centralized EMS database of patients transported by EMS to the ED for suspected stroke during an 18-month period. Hospital charts and neuroimaging were utilized to determine the final diagnosis (acute stroke, stroke mimic, as well as specific underlying diagnoses). Results: A total of 960 patients were transported by EMS to the ED with suspected stroke, among whom 405 (42.2%) were stroke mimics (mean age ± SD: 66.9 ± 17.1 years; 54% male). Stroke mimics were neurological in origin in 223 (55.1%) patients and non-neurological in 182 (44.9%). Most common neurological diagnoses were seizures (n=44,19.7%), migraines (n=42,18.8%) and peripheral neuropathies (n=25, 11.2%). Most common non-neurological mimics included cardiovascular (15.9%), psychiatric (11.9%), and infectious (8.9%) diagnoses. Neurological mimics were younger (64.1 ± 17.3 years) than non-neurological mimics (70.5 ± 16.1 years, p<0.001). Median prehospital Glasgow Coma Scale scores were similar between groups (15 vs. 15, p=0.26). Mean prehospital systolic blood pressure was slightly higher in neurological (147.8±24.2 mmHg) than non-neurological mimics (141.2±26.2 mmHg, p=0.01). Conclusions: Stroke mimics represent a substantial number of patients transported by EMS for suspected stroke, with a considerable amount being non-neurological in origin. Prospective prehospital studies are warranted to help refine prehospital identification of acute stroke and thus minimize the number of stroke mimics transported by EMS for acute stroke evaluation.

The effectiveness of apneic oxygenation during tracheal intubation in various clinical settings: a narrative review.

During the process of tracheal intubation, patients are apneic or hypoventilating and are at risk of becoming hypoxemic. This risk is especially high in patients with acute or chronic respiratory failure and accompanying compromised respiratory reserve. To address this concern, apneic oxygenation can be administered during tracheal intubation to aid in maintaining arterial oxygen saturation. The objective of this narrative review is to examine the utilization of apneic oxygenation within the operating room, intensive care unit (ICU), emergency department, and pre-hospital settings and to determine its efficacy compared with controls. For this narrative review, we obtained pertinent articles using MEDLINE® (1946 to April 2016), EMBASE™ (1974 to April 2016), Google Scholar, and manual searches. Apneic oxygenation was administered using various techniques, including the use of nasal prongs, nasopharyngeal or endotracheal catheters, or laryngoscopes. First, all 12 operating room studies showed that apneic oxygenation significantly prolonged the duration to, and incidence of, desaturation. Second, two of the five ICU studies showed a significantly smaller decline in oxygen saturation with apneic oxygenation, with three studies showing no statistically significant difference vs controls. Lastly, two emergency department or pre-hospital studies showed that the use of apneic oxygenation resulted in a significantly lower incidence of desaturation and smaller declines in oxygen saturation. Sixteen of the 19 studies showed that apneic oxygenation prolongs safe apneic time and reduces the incidence of arterial oxygen desaturation. Overall, studies in this review show that apneic oxygenation prolongs the time to oxygen desaturation during tracheal intubation. Nevertheless, the majority of the studies were small in size, and they neither measured nor were adequately powered to detect adverse respiratory events or other serious rare complications. Prolonged apneic oxygenation (with its consequent hypercarbia) can have risks and should be avoided in patients with conditions such as increased intracranial pressure, metabolic acidosis, hyperkalemia, and pulmonary hypertension.

Guidance Document for the Prehospital Use of Tranexamic Acid in Injured Patients

Tranexamic acid (TXA) is being administered already in many prehospital air and ground systems. Insufficient evidence exists to support or refute the prehospital administration of TXA, and results are pending from several prehospital studies currently in progress. We have created this document to aid agencies and systems in best practices for TXA administration based on currently available best evidence. This document has been endorsed by the American College of Surgeons–Committee on Trauma, the American College of Emergency Physicians, and the National Association of EMS Physicians.

Development of research governance awareness to support pre-hospital studies

Background: Development of new evidence to support pre-hospital emergency care benefits both patients and practitioners. Clinical research must be conducted within a formal governance framework but it is challenging for paramedics to access traditional good clinical practice (GCP) training due to high service demands and some content is of little relevance to the pre-hospital setting. Objective: To establish the content and format of easily accessible research governance awareness training for use by paramedics and other members of the ambulance service as and when appropriate. Methods: A systematic literature review identified descriptions of pre-hospital research training. An online survey sought views about the formal research training undertaken by NHS paramedics and an expert consensus process confirmed the content of training materials. Results: Research governance training was rarely acknowledged in pre-hospital clinical trial literature and was recalled by only one in eight respondents who had assisted with clinical research. A pre-hospital orientated slide set and matching assessment questions were reviewed in two cycles by an expert panel to achieve a consensus on the content and format. Conclusions: Through a structured process of literature review, stakeholder engagement and expert consensus we have developed training and assessment materials which can be used flexibly to prepare paramedics and the wider ambulance workforce for safe hosting of low-risk research activities.

The efficacy of hydrogel dressings as a first aid measure for burn wound management in the pre-hospital setting: a systematic review of the literature.

The aim of this systematic review was to determine the supporting evidence for the clinical use of hydrogel dressings as a first aid measure for burn wound management in the pre-hospital setting. Two authors searched three databases (Ovid Medline, Ovid Embase and The Cochrane Library) for relevant English language articles published through September 2014. Reference lists, conference proceedings and non-indexed academic journals were manually searched. A separate search was conducted using the Internet search engine Google to source additional studies from burns advisory agencies, first aid bodies, military institutions, manufacturer and paramedic websites. Two authors independently assessed study eligibility and relevance of non-traditional data forms for inclusion. Studies were independently assessed and included if Hydrogel-based burn dressings (HBD) were examined in first aid practices in the pre-hospital setting. A total of 129 studies were considered for inclusion, of which no pre-hospital studies were identified. The review highlights that current use of HBD in the pre-hospital setting appears to be driven by sources of information that do not reflect the paramedic environment. We recommend researchers in the pre-hospital settings undertake clinical trials in this field. More so, the review supports the need for expert consensus to identify key demographic, clinical and injury outcomes for clinicians and researchers undertaking further research into the use of dressings as a first aid measure.

A pilot study of angiotensin converting enzyme (ACE) genotype and return of spontaneous circulation following out-of-hospital cardiac arrest

ObjectiveIn the last few years the genetic influence on health and disease outcome has become more apparent. The ACE genotype appears to play a significant role in the pathophysiology of...

Review of new topical hemostatic dressings for combat casualty care.

This review analyzes the new (2008-2013) hemostatic agents and dressings for enhanced efficacy in preclinical studies, and investigates supportive findings among case reports of effectiveness and safety in hospital and prehospital literature. A literature search was conducted using PubMed, National Library of Medicine using key words and phrases. The search revealed a total of 16 articles that fit the criteria established for third-generation hemostatic dressings. There were a total of 9 preclinical, 5 clinical, and 2 prehospital studies evaluated. Evaluation of these third-generation studies reveals that mucoadhesive (chitosan) dressings, particularly Celox Gauze and ChitoGauze, clearly show equal efficacy to Combat Gauze across many dependent variables. Chitosan-based products are ideal prehospital dressings because they are shown to work independently from the physiological clotting mechanisms. Many first-, second-, and third-generation chitosan-based dressings have been in use for years by the United States and other NATO militaries at the point of injury, and during tactical evacuation, in Operation Enduring Freedom and Operation Iraqi Freedom without reported complications or side effects. Based on the reported efficacy and long-term safety of chitosan-based products, increased use of Celox Gauze and ChitoGauze within the Department of Defense and civilian venues merits further consideration and open debate.

The Airtraq as a Primary and Rescue Device in the Prehospital Setting

Several studies have shown that the Airtraq, a self-powered, single-use, indirect laryngoscope, has a higher intubation success rate than direct laryngoscopy, particularly for novice intubators (NEJM Journal Watch Emerg Med Dec 2 2011). To assess use of the device in the prehospital setting, researchers in Sweden performed a retrospective chart review of prehospital endotracheal intubations over a 5-year period. The Airtraq was used in 28 of 2453 intubations (1%). Of these 28 patients, 23 were in cardiac arrest. The overall success rate was 68%. The success rate was 61% in the 23 cases in which the device was used for anticipated or unexpected difficult airway. Of 13 patients with failed prior attempts at intubation with conventional laryngoscopy or a laryngeal mask airway, 46% were intubated successfully with the Airtraq. Airtraq intubation failures were rescued with combinations of direct laryngoscopy, use of a bougie, and blind nasal intubation. Comment: The Airtraq intubation success rate in this study (68%) is higher than that in the only prospective prehospital study (47%), but is lower than that in other, prior prehospital studies. The small number of Airtraq intubations in this study limits extrapolation of the findings, and the study fails to further clarify the device's role in prehospital difficult airways. Larger studies comparing the Airtraq to both video and direct laryngoscopes are needed. As with every intubation technique, provider familiarity and experience is paramount for success. Citation(s):

Effectiveness and Safety of Paramedic Administration of Verapamil and Adenosine for the Treatment of Supraventricular Tachycardia: A Review of the Literature

Introduction Adenosine and verapamil are the most commonly used pharmacological agents to treat supraventricular tachycardia (SVT). This review aims to identify the effectiveness and safety of pre-hospital use of adenosine and verapamil by paramedics. Methods A comprehensive electronic literature search was conducted. Studies of pre-hospital comparative effectiveness of adenosine and verapamil were included for further analysis. Studies where individual effectiveness of either verapamil or adenosine was reported in either the medical or pre-hospital setting were excluded. Animal studies and those articles unavailable in English were also excluded. Results Two pre-hospital studies were identified. Verapamil demonstrated greater reversion effectiveness across both studies, with side effects more commonly reported in the adenosine arm of each. The duration and severity of side effects resulting from verapamil administration was greater than that of adenosine. Paramedic electrocardiogram (ECG) interpretation was questionable, resulting in a number of errors across both studies. Conclusion Available studies report that verapamil is more effective for pre-hospital SVT reversion. Effective pre-hospital drug therapy for SVT must incorporate a measure of patient impact with regard to severity, duration and interventions required to correcting adverse effects. A larger contemporary study is required to further evidence paramedic use of pharmacological agents to treat SVT. Paramedic ECG interpretation is a key factor influencing correct treatment, and adequate education must form the basis of pre-hospital guidelines for SVT management.

Pre-hospital management and outcome of acute poisonings by ambulances in Yekaterinburg, Russia

Introduction. Large, prospective pre-hospital studies of acute poisonings are scarce. We present the epidemiology of the pre-hospital poisonings, the treatment given, the complications of the poisoning itself and the treatment, predictors for hospitalization, and the safety of the present approach in a large industrial Russian city. Methods. Data were collected from March 2009 to March 2010. All adult (≥ 16 years) acute poisonings in the city of Yekaterinburg, Russia were included. The prospective cohort inclusion of data included age, gender, simple clinical features (including consciousness, respiratory status, circulatory status, convulsions, etc.), main toxic agent, reason why poisoning was suspected, treatment given, and outcome. Multivariate logistic regression analysis was used to identify the factors associated with hospitalization of the patients. Results. In total, 1795/2536 patients (71%) were brought to hospitals, 736/2536 (29%) were discharged by the ambulance, and 5/2536 (0.2%) died on scene. The most frequent main agents were opioids (25%), ethanol (9%), benzodiazepines (8%), corrosive substances (7%), carbon monoxide (5%), and neuroleptics (5%). Pre-hospital treatment was given to 73% of patients; 3% were intubated, and antidotes were given in 27% (naloxone 24%, atropine 2%, and flumazenil 0.2%). Gastric lavage was performed in 34%, but only 20% within the first hour after ingestion; 49% had a Glasgow Coma Scale (GCS)< 15, but only 6% of them were intubated in the ambulance. Activated charcoal was given to two patients, both with a GCS = 15. A suicidal behavior was the strongest predictor for hospitalization. Conclusion. This study reveals current practice differing from the common treatment practice in most places, especially concerning the use of gastric lavage. Whether the current practice led to an increased morbidity and mortality is uncertain, but it justifies the need for thorough evaluation of clinical practice. These findings highlight the importance of studies like the present to improve diagnostics, triage, and treatment in acute poisonings.

Pre-hospital femoral neck fracture management: A review of the literature

Introduction: Falls are a common incident in the pre-hospital setting with a significant number resulting in fractures to the femoral neck. There is some disagreement as to the best way to manage this injury, especially the immobilisation of the affected leg. The objective of the study was to review the literature evaluating the best practice management of patients who present with a femoral neck fracture in the Australian pre-hospital setting. Methods: A literature search was conducted using medical electronic databases, Medline, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) from the beginning of each database until the end of September 2012. Articles were included if they reported the pre-hospital management of a patient with a femoral neck fracture. Non-English and hospital-based articles were excluded. References from articles retrieved were reviewed. Results: There were 49 articles located with five articles meeting the inclusion criteria. All five articles described the evaluation of pain management techniques for patients presenting with injuries to the femoral neck. There were no studies that investigated the immobilisation of a femoral neck fracture. Conclusions: This study found a lack of evidence for the management of pre-hospital femoral neck fractures in Australia. Further pre-hospital studies are required to determine the most effective pain management technique as well as the best method to immobilise a femoral neck fracture.

Rapid P2Y 12 Inhibition

Acute coronary syndrome (ACS) is still a serious condition associated with decreased quality of life, increased healthcare expenditures, and premature death. The prevalence of ACS is expected to increase with aging of the population and with the epidemics of obesity and diabetes. The short- and long-term mortality after an ACS has been dramatically reduced by the development of revascularization techniques and new antithrombotic agents. The past decade has seen many trials evaluating new oral and parenteral antiplatelet agents with greater potency than aspirin and clopidogrel. Several antiplatelet agents have been developed, with the ultimate goal to obtain optimal antiplatelet therapy for both the acute and the chronic phases of disease. Articles see p 336, 347 Ideally, efficiency requires several pharmacodynamic proprieties, such as a fast onset of action (immediate onset for emergency situations), a strong degree of platelet inhibition (at least stronger than the standard of care [aspirin and clopidogrel]), a narrow interindividual variability with no impact of genetic variants and no drug-to-drug interaction, and an easy administration (an oral drug for maintenance therapy and an intravenous formulation for rapid loading). Of course, this drug should also lead to a convincing reduction of recurrent ischemic events in an adequately powered phase 3 trial. With regard to safety, the illusion of having the same dose of a single antiplatelet drug to treat all clinical situations has passed. The degree of platelet activation and aggregation is different across clinical situations (eg, acute ST-segment–elevation myocardial infarction [STEMI] versus secondary prevention) and varies over time in the same patient. Recent large phase 3 trials have confirmed the importance of dosing and the target population treated with the new agents.1–4 From a safety standpoint, an ideal antiplatelet agent would also have an intravenous and oral formulation, with different doses tested in …

Abstract 66: Ischemic Lesion Evolution and Hemorrhagic Transformation After Thrombolysis with Neuroprotection in FAST-MAG

Background: The frequency and range of early infarct signs in acute cerebral ischemia patients have been described in several 6-24 hour cohorts, but are incompletely characterized among under 2 hour presenting patients who actually proceed to receive IV tissue plasminogen activator (tPA). Prompt treatment with tPA improves outcomes after acute ischemic stroke, providing a platform to test promising neuroprotective strategies. We analyzed baseline and 24-hour imaging studies in an initial cohort of thrombolysis cases in the FAST-MAG trial of prehospital initiation of neuroprotection. Methods: Baseline and 24-hour CT/MRI studies acquired in 100 consecutive patients enrolled in FAST-MAG and treated with intravenous tPA were rated by two imaging experts for the presence of early ischemic changes (EIC), hyperdense vessel signs (HVS), ASPECTS score, white matter hyperintensities, prior infarction, lesion pattern and hemorrhagic transformation (HT), blind to all other data in the trial. Results: Among the 100 patients, mean age was 72±13 years; 44% were women; and median NIHSS was 14 (IQR 8-20). Initial imaging was obtained a mean of 91±29 minutes after last known well and routine post-thrombolysis imaging was obtained a mean of 23±13 hours later. Modality for initial scans was CT in 92% and MRI in 8%, and for follow-up scans CT in 63% and MRI in 37%. EIC were noted in 44%, including insular ribbon sign in 35%, lenticular obscuration in 28% and cortical effacement in 10%. HVS was visualized in 50%. Initial ASPECTS was median 9 (IQR 8-10) and 7 (IQR 4-9) at 24 hours. 24-hour lesion patterns were characterized as predominantly cortical in 50%, subcortical in 19%, scattered in 23% and no lesion in 8%. At 24 hours, ASPECTS correlated with NIHSS (R=-0.409, p&lt;0.001) whereas specific lesion patterns did not (p=NS). Cortical lesion patterns at 24 hours were predicted by cortical effacement on initial CT (23% vs. 0%, p=0.011). HT occurred in 26%, including 15% HI1, 3% HI2, 4% PH1, 3% PH2 and 1% IVH. Factors associated with HT were lower baseline ASPECTS (7.5 vs. 8.7, p=0.002) and more severe baseline NIHSS (18 vs. 13, p=0.021). Conclusions: Among patients imaged a mean of 1.5 hours after onset and then treated with thrombolysis, hyperdense vessel signs are present in one-half and early signs of ischemic parenchymal injury are present in nearly half, but are generally mild. Observed rates of HT were low. Serial imaging of patients treated with field neuroprotective therapies followed by post-arrival thrombolysis is often informative at initial and follow-up time points and has potential as biomarkers to interrogate treatment effects in prehospital neuroprotection studies.

Empiric Management of Cyanide Toxicity Associated with Smoke Inhalation

Enclosed-space smoke inhalation is the fifth most common cause of all unintentional injury deaths in the United States. Increasingly, cyanide has been recognized as a significant toxicant in many cases of smoke inhalation. However, it cannot be emergently verified. Failure to recognize the possibility of cyanide toxicity may result in inadequate treatment. Findings suggestive cyanide toxicity include: (1) a history of an enclosed-space fire scene in which smoke inhalation was likely; (2) the presence of oropharyngeal soot or carbonaceous expectorations; (3) any alteration of the level of consciousness, and particularly, otherwise inexplicable hypotension (systolic blood pressure ≤90 mmHg in adults). Prehospital studies have demonstrated the feasibility and safety of empiric treatment with hydroxocobalamin for patients with suspected smoke inhalation cyanide toxicity. Although United States Food and Drug Administration (FDA)-approved since 2006, the lack of efficacy data has stymied the routine use of this potentially lifesaving antidote. Based on a literature review and on-site observation of the Paris Fire Brigade, emergency management protocols to guide empiric and early hydroxocobalamin administration in smoke inhalation victims with high-risk presentations are proposed.

Prehospital Use of Continuous Positive Airway Pressure for Acute Severe Congestive Heart Failure

BackgroundThe utility of continuous positive airway pressure (CPAP) in the in-hospital treatment of congestive heart failure (CHF) is well established. Its exact role is less clear in the prehospital arena. ObjectiveTo describe the prehospital use of CPAP for patients presenting with acute severe heart failure in a large Emergency Medical Services system in New Jersey. MethodsRetrospective review of prehospital charts from January 1, 2005 to December 31, 2006 of patients treated for acute CHF. Inclusion criteria for eligibility for CPAP mask use were: respiratory rate > 25 breaths/min, labored and shallow breathing, bilateral rales, history of CHF, intact mental status, and prehospital clinical diagnosis of CHF. Data collected included demographics, vital signs, oxygen saturation (SaO2), need for endotracheal intubation (ETI), and complications. ResultsThere were 1306 charts reviewed; 387 patients met inclusion criteria. Of the 387, 149 patients had placement of CPAP (38.5%). The prehospital treatment times were (CPAP = 30 min; non-CPAP = 31 min; p < 0.01). The increase in SaO2 for the CPAP group (9%) vs. the non-CPAP group (5%) was statistically significant (p < 0.01). Systolic blood pressure (BP) reduction (CPAP [27.1 mm Hg], non-CPAP [19.9 mm Hg], p < 0.01), diastolic BP reduction (CPAP [14.1 mm Hg], non-CPAP [7.4 mm Hg], p < 0.01), heart rate reduction (CPAP [17.2 beats/min], non-CPAP [9.6 beats/min], p < 0.01), respiratory rate reduction (CPAP [5.63], non-CPAP [4.09], p < 0.01), and ETI reduction (CPAP [2.6%], non-CPAP [5.46%], p < 0.01), all were statistically significant. Adjunctive CHF treatments were similar between the groups. ConclusionThe use of CPAP for eligible patients with acute severe CHF seems to be feasible and beneficial. Large-scale randomized prospective prehospital studies are needed to validate these results.