Understanding traumatic shock: out-of-hospital hypotension with and without other physiologic compromise

BACKGROUND

Among trauma patients with out-of-hospital hypotension, we evaluated the predictive value of systolic blood pressure (SBP) with and without other physiologic compromise for identifying trauma patients requiring early critical resources.

METHODS

This was a secondary analysis of a prospective cohort of injured patients 13 years or older with out-of-hospital hypotension (SBP ≤ 90 mm Hg) who were transported by 114 emergency medical service agencies to 56 Level I and II trauma centers in 11 regions of the United States and Canada from January 1, 2010, through June 30, 2011. The primary outcome was early critical resource use, defined as blood transfusion of 6 U or greater, major nonorthopedic surgery, interventional radiology, or death within 24 hours.

RESULTS

Of 3,337 injured patients with out-of-hospital hypotension, 1,094 (33%) required early critical resources and 1,334 (40%) had serious injury (Injury Severity Score [ISS] ≥ 16). Patients with isolated hypotension required less early critical resources (14% vs. 52%), had less serious injury (20% vs. 61%), and had lower mortality (24 hours, 1% vs. 26%; in-hospital, 3% vs. 34%). The standardized probability of requiring early critical resources was lowest among patients with blunt injury and isolated moderate hypotension (0.12; 95% confidence interval, 0.09-0.15) and steadily increased with additional physiologic compromise, more severe hypotension, and penetrating injury (0.94; 95% confidence interval, 0.90-0.98).

CONCLUSION

A minority of trauma patients with isolated out-of-hospital hypotension require early critical resuscitation resources. However, hypotension accompanied by additional physiologic compromise or penetrating injury markedly increases the probability of requiring time-sensitive interventions.

LEVEL OF EVIDENCE

Prognostic study, level II.

Revisiting the "Golden Hour": An Evaluation of Out-of-Hospital Time in Shock and Traumatic Brain Injury

STUDY OBJECTIVE

We evaluate patients with shock and traumatic brain injury who were previously enrolled in an out-of-hospital clinical trial to test the association between out-of-hospital time and outcome.

METHODS

This was a secondary analysis of patients with shock and traumatic brain injury who were aged 15 years or older and enrolled in a Resuscitation Outcomes Consortium out-of-hospital clinical trial by 81 emergency medical services agencies transporting to 46 Level I and II trauma centers in 11 sites (May 2006 through May 2009). Inclusion criteria were systolic blood pressure less than or equal to 70 mm Hg or systolic blood pressure 71 to 90 mm Hg with pulse rate greater than or equal to 108 beats/min (shock cohort) and Glasgow Coma Scale score less than or equal to 8 (traumatic brain injury cohort); patients meeting both criteria were placed in the shock cohort. Primary outcomes were 28-day mortality (shock cohort) and 6-month Glasgow Outcome Scale-Extended score less than or equal to 4 (traumatic brain injury cohort).

RESULTS

There were 778 patients in the shock cohort (26% 28-day mortality) and 1,239 patients in the traumatic brain injury cohort (53% 6-month Glasgow Outcome Scale-Extended score ≤4). Out-of-hospital time greater than 60 minutes was not associated with worse outcomes after accounting for important confounders in the shock cohort (adjusted odds ratio [aOR] 1.42; 95% confidence interval [CI] 0.77 to 2.62) or traumatic brain injury cohort (aOR 0.77; 95% CI 0.51 to 1.15). However, shock patients requiring early critical hospital resources and arriving after 60 minutes had higher 28-day mortality (aOR 2.37; 95% CI 1.05 to 5.37); this finding was not observed among a similar traumatic brain injury subgroup.

CONCLUSION

Among out-of-hospital trauma patients meeting physiologic criteria for shock and traumatic brain injury, there was no association between time and outcome. However, the subgroup of shock patients requiring early critical resources and arriving after 60 minutes had higher mortality.

Variability in early do not attempt resuscitation orders among patients with serious traumatic brain injury

OBJECTIVES

The objective was describe the use of early do not attempt resuscitation (DNAR) orders in patients with serious traumatic brain injury (TBI) and its association with outcomes.

METHODS

This was a retrospective cohort study of all serious TBI patients admitted through the emergency department (ED) to acute care hospitals in California between 2002 and 2010 using ED International Classification of Diseases, 9th revision (ICD-9), admitting diagnosis codes specifying intracranial hemorrhage. DNAR placement within 24 hours of admission was the primary variable of interest. Outcomes included neurosurgical procedures and in-hospital mortality. Hospital and patient characteristics were analyzed using descriptive statistics and multivariable generalized estimation equation regression models to account for hospital-level clustering.

RESULTS

Of all 76,962 patients with serious TBI, 71,275 were admitted at 141 hospitals that each cared for at least 10 serious TBI patients annually and formed the primary sample. Early DNAR orders were placed in 7.5% of patients (range = 0 to 36.1% by hospital). Early DNAR use varied by trauma designation: Level I, 4.0% (95% confidence interval [CI] = 3.8% to 4.4%); Level II, 6.7% (95% CI = 6.5% to 7.1%); Level III, 9.7% (95% CI = 8.4% to 11.3%); and nontrauma hospitals, 10.8% (95% CI = 10.6% to 11.3%). Early DNAR was also less likely in teaching hospitals (9.3% vs. 4.3%). These results persisted after accounting for age, year, and hospital-level clustering. In-hospital mortality (39.4% vs. 8.7%) and neurosurgical interventions (14.5% vs. 19.7%) also differed for patients with versus without early DNAR orders. Patients 65 years of age and older constituted 87.7% of those with early DNAR orders; our findings remained qualitatively unchanged when restricted to older adults.

CONCLUSIONS

Use of early DNAR orders among patients with serious TBI is highly variable by individual hospital and hospital type, suggesting substantial practice variation. Associations with fewer surgical intervention and higher mortality suggest that such practice variation may be contributing to differences in TBI outcomes, particularly among older adults.

Increased trauma center volume is associated with improved survival after severe injury: results of a Resuscitation Outcomes Consortium study

OBJECTIVE

To investigate the relationship between trauma center volume and outcome.

BACKGROUND

The Resuscitation Outcomes Consortium is a network of 11 centers and 60 hospitals conducting emergency care research. For many procedures, high-volume centers demonstrate superior outcomes versus low-volume centers. This remains controversial for trauma center outcomes.

METHODS

This study was a secondary analysis of prospectively collected data from the Resuscitation Outcomes Consortium multicenter out-of-hospital Hypertonic Saline Trial in patients with Glasgow Coma Scale score of 8 or less (traumatic brain injury) or systolic blood pressure of 90 or less and pulse of 110 or more (shock). Regression analyses evaluated associations between trauma volume and the following outcomes: 24-hour mortality, 28-day mortality, ventilator-free days, Multiple Organ Dysfunction Scale incidence, worst Multiple Organ Dysfunction Scale score, and poor 6-month Glasgow Outcome Scale-Extended score.

RESULTS

A total of 2070 patients were evaluated: 1251 in the traumatic brain injury cohort and 819 in the shock cohort. Overall, 24-hour and 28-day mortality was 16% and 25%, respectively. For every increase of 500 trauma center admissions, there was a 7% decreased odds of 24-hour and 28-day mortality for all patients. As trauma center volume increased, nonorgan dysfunction complications increased, ventilator-free days increased, and worst Multiple Organ Dysfunction Scale score decreased. The associations with higher trauma center volume were similar for the traumatic brain injury cohort, including better neurologic outcomes at 6 months, but not for the shock cohort.

CONCLUSIONS

Increased trauma center volume was associated with increased survival, more ventilator-free days, and less severe organ failure. Trauma system planning and implementation should avoid unnecessary duplication of services.

Physiologic field triage criteria for identifying seriously injured older adults

OBJECTIVE

To evaluate the ability of out-of-hospital physiologic measures to predict serious injury for field triage purposes among older adults and potentially reduce the undertriage of seriously injured elders to non-trauma hospitals.

METHODS

This was a retrospective cohort study involving injured adults 55 years and older transported by 94 emergency medical services (EMS) agencies to 122 hospitals (trauma and non-trauma) in 7 regions of the western United States from January 1, 2006 to December 31, 2008. We evaluated initial out-of-hospital Glasgow Coma Scale (GCS) score, systolic blood pressure (SBP), respiratory rate, heart rate, shock index (SBP ÷ heart rate), out-of-hospital procedures, mechanism of injury, and patient demographics. The primary outcome was "serious injury," defined as Injury Severity Score (ISS) ≥ 16, as a measure of trauma center need. We used multivariable regression models, fractional polynomials and binary recursive partitioning to evaluate appropriate physiologic cut-points and the value of different physiologic triage criteria.

RESULTS

A total of 44,890 injured older adults were evaluated and transported by EMS, of whom 2,328 (5.2%) had ISS ≥ 16. Nonlinear associations existed between all physiologic measures and ISS ≥ 16 (unadjusted and adjusted p ≤ 0.001 for all,), except for heart rate (adjusted p = 0.48). Revised physiologic triage criteria included GCS score ≤ 14; respiratory rate < 10 or > 24 breaths per minute or assisted ventilation; and SBP < 110 or > 200 mmHg. Compared to current triage practices, the revised criteria would increase triage sensitivity from 78.6 to 86.3% (difference 7.7%, 95% CI 6.1-9.6%), reduce specificity from 75.5 to 60.7% (difference 14.8%, 95% CI 14.3-15.3%), and increase the proportion of patients without serious injuries transported to major trauma centers by 60%.

CONCLUSIONS

Existing out-of-hospital physiologic triage criteria could be revised to better identify seriously injured older adults at the expense of increasing overtriage to major trauma centers.

The cost of overtriage: more than one-third of low-risk injured patients were taken to major trauma centers

Regionalized trauma care has been widely implemented in the United States, with field triage by emergency medical services (EMS) playing an important role in identifying seriously injured patients for transport to major trauma centers. In this study we estimated hospital-level differences in the adjusted cost of acute care for injured patients transported by 94 EMS agencies to 122 hospitals in 7 regions, overall and by injury severity. Among 301,214 patients, the average adjusted per episode cost of care was $5,590 higher in a level 1 trauma center than in a nontrauma hospital. We found hospital-level differences in cost among patients with minor, moderate, and serious injuries. Of the 248,342 low-risk patients-those who did not meet field triage guidelines for transport to trauma centers-85,155 (34.3 percent) were still transported to major trauma centers, accounting for up to 40 percent of acute injury costs. Adhering to field triage guidelines that minimize the overtriage of low-risk injured patients to major trauma centers could save up to $136.7 million annually in the seven regions we studied.

Addressing the challenges of obtaining functional outcomes in traumatic brain injury research: missing data patterns, timing of follow-up, and three prognostic models

Traumatic brain injury (TBI) is common and debilitating. Randomized trials of interventions for TBI ideally assess effectiveness by using long-term functional neurological outcomes, but such outcomes are difficult to obtain and costly. If there is little change between functional status at hospital discharge versus 6 months, then shorter-term outcomes may be adequate for use in future clinical trials. Using data from a previously published multi-center, randomized, placebo-controlled TBI clinical trial, we evaluated patterns of missing outcome data, changes in functional status between hospital discharge and 6 months, and three prognostic models to predict long-term functional outcome from covariates available at hospital discharge (functional measures, demographics, and injury characteristics). The Resuscitation Outcomes Consortium Hypertonic Saline trial enrolled 1282 TBI patients, obtaining the primary outcome of 6-month Glasgow Outcome Score Extended (GOSE) for 85% of patients, but missing the primary outcome for the remaining 15%. Patients with missing outcomes had less-severe injuries, higher neurological function at discharge (GOSE), and shorter hospital stays than patients whose GOSE was obtained. Of 1066 (83%) patients whose GOSE was obtained both at hospital discharge and at 6-months, 71% of patients had the same dichotomized functional status (severe disability/death vs. moderate/no disability) after 6 months as at discharge, 28% had an improved functional status, and 1% had worsened. Performance was excellent (C-statistic between 0.88 and 0.91) for all three prognostic models and calibration adequate for two models (p values, 0.22 and 0.85). Our results suggest that multiple imputation of the standard 6-month GOSE may be reasonable in TBI research when the primary outcome cannot be obtained through other means.

Variation in prehospital use and uptake of the national Field Triage Decision Scheme

BACKGROUND

The Field Triage Decision Scheme is a national guideline that has been implemented widely for prehospital emergency medical services (EMS) and trauma systems. However, little is known about the uptake, modification, or variation in field application of triage criteria between trauma systems.

OBJECTIVE

To describe and compare the use of field triage criteria by EMS personnel in six regions, including the timing of guideline uptake and the use of nonguideline criteria.

METHODS

This was a retrospective cohort study of injured children and adults transported by 48 EMS agencies to 105 hospitals (trauma centers and non-trauma centers) in six Western U.S. regions from 2006 through 2008. We used probabilistic linkage to match patient-level prehospital information from multiple sources, including EMS records, base-hospital phone communication records, and trauma registry data files. Triage criteria were evaluated individually and grouped by "steps" (physiologic, anatomic, mechanism, and special considerations). We used descriptive statistics to compare the frequency of triage criteria use (overall and between regions) and to evaluate the timing of guideline uptake across multiple versions of the guidelines.

RESULTS

A total of 260,027 injured patients were evaluated and transported by EMS over the three-year study period, of whom 46,414 (18%) met at least one field triage criterion and formed the primary sample for analysis. The three most common criteria cited (of 33 in use) were EMS provider judgment (26%), age <5 or >55 years (10%), and Glasgow Coma Scale (GCS) score <14 (9%). Of the 33 criteria in use, five (15%) were previously retired from the guidelines and seven (21%) were never included in the guidelines. 11,048 (24%) patients had more than one criterion applied (range 1-21). There was large variation in the type and frequency of criteria used between systems, particularly among the nonphysiologic triage steps. Only one of six regions had translated the most recent guidelines into field use within two years after release.

CONCLUSION

There is large variation between regions in the frequency and type of field triage criteria used. Field uptake of guideline revisions appears to be slow and variable, suggesting opportunities for improvement in dissemination and implementation of updated guidelines.

Triage of elderly trauma patients: a population-based perspective

BACKGROUND

Elderly patients are frequently undertriaged. However, the associations between triage patterns and outcomes from a population perspective are unknown. We hypothesized that triage patterns would be associated with differences in outcomes.

STUDY DESIGN

This is a population-based, retrospective, cohort study of all injured adults aged 55 years or older, from 3 counties in California and 4 in Utah (2006 to 2007). Prehospital data were linked to trauma registry data, state-level discharge data, emergency department records, and death files. The primary outcome was 60-day mortality. Patients treated at trauma centers were compared with those treated at nontrauma centers. Undertriage was defined as an Injury Severity Score (ISS) >15, with transport to a nontrauma center.

RESULTS

There were 6,015 patients in the analysis. Patients who were taken to nontrauma centers were, on average, older (79.4 vs 70.7 years, p < 0.001), more often female (68.6% vs 50.2%, p < 0.01), and less often had an ISS >15 (2.2% vs 6.7%, p < 0.01). There were 244 patients with an ISS >15 and the undertriage rate was 32.8% (n = 80). Overall 60-day mortality for patients with an ISS >15 was 17%, with no difference between trauma and nontrauma centers in unadjusted or adjusted analyses. However, the median per-patient costs were $21,000 higher for severely injured patients taken to trauma centers.

CONCLUSIONS

This is the first population-based analysis of triage patterns and outcomes in the elderly. We have shown high rates of undertriage that are not associated with higher mortality, but are associated with higher costs. Future work should focus on determining how to improve outcomes for this population.

Gunshot injuries in children served by emergency services

OBJECTIVE

To describe the incidence, injury severity, resource use, mortality, and costs for children with gunshot injuries, compared with other injury mechanisms.

METHODS

This was a population-based, retrospective cohort study (January 1, 2006-December 31, 2008) including all injured children age ≤ 19 years with a 9-1-1 response from 47 emergency medical services agencies transporting to 93 hospitals in 5 regions of the western United States. Outcomes included population-adjusted incidence, injury severity score ≥ 16, major surgery, blood transfusion, mortality, and average per-patient acute care costs.

RESULTS

A total of 49,983 injured children had a 9-1-1 emergency medical services response, including 505 (1.0%) with gunshot injuries (83.2% age 15-19 years, 84.5% male). The population-adjusted annual incidence of gunshot injuries was 7.5 cases/100,000 children, which varied 16-fold between regions. Compared with children who had other mechanisms of injury, those injured by gunshot had the highest proportion of serious injuries (23%, 95% confidence interval [CI] 17.6-28.4), major surgery (32%, 95% CI 26.1-38.5), in-hospital mortality (8.0%, 95% CI 4.7-11.4), and costs ($28,510 per patient, 95% CI 22,193-34,827).

CONCLUSIONS

Despite being less common than other injury mechanisms, gunshot injuries cause a disproportionate burden of adverse outcomes in children, particularly among older adolescent males. Public health, injury prevention, and health policy solutions are needed to reduce gunshot injuries in children.

Patient choice in the selection of hospitals by 9-1-1 emergency medical services providers in trauma systems

OBJECTIVES

Reasons for undertriage (transporting seriously injured patients to nontrauma centers) and the apparent lack of benefit of trauma centers among older adults remain unclear; understanding emergency medical services (EMS) provider reasons for selecting certain hospitals in trauma systems may provide insight to these issues. In this study, the authors evaluated reasons cited by EMS providers for selecting specific hospital destinations for injured patients, stratified by age, injury severity, field triage status, and prognosis.

METHODS

This was a retrospective cohort study of injured children and adults transported by 61 EMS agencies to 93 hospitals (trauma and nontrauma centers) in five regions of the western United States from 2006 through 2008. Hospital records were probabilistically linked to EMS records using trauma registries, state discharge data, and emergency department data. The seven standardized reasons cited by EMS providers for selecting hospital destinations included closest facility, ambulance diversion, physician choice, law enforcement choice, patient or family choice, specialty resource center, and other. "Serious injury" was defined as an Injury Severity Score (ISS) ≥ 16, and unadjusted in-hospital mortality was considered as a marker of prognosis. All analyses were stratified by age in 10-year increments, and descriptive statistics were used to characterize the findings.

RESULTS

A total of 176,981 injured patients were evaluated and transported by EMS over the 3-year period, of whom 5,752 (3.3%) had ISS ≥ 16 and 2,773 (1.6%) died. Patient or family choice (50.6%), closest facility (20.7%), and specialty resource center (15.2%) were the most common reasons indicated by EMS providers for selecting destination hospitals; these frequencies varied substantially by patient age. The frequency of patient or family choice increased with increasing age, from 36.4% among 21- to 30-year-olds to 75.8% among those older than 90 years. This trend paralleled undertriage rates and persisted when restricted to patients with serious injuries. Older patients with the worst prognoses were preferentially transported to major trauma centers, a finding that was not explained by field triage protocols.

CONCLUSIONS

Emergency medical services transport patterns among injured patients are not random, even after accounting for field triage protocols. The selection of hospitals appears to be heavily influenced by patient or family choice, which increases with patient age and involves inherent differences in patient prognosis.

Predicting ambulance time of arrival to the emergency department using global positioning system and Google maps

OBJECTIVE

To derive and validate a model that accurately predicts ambulance arrival time that could be implemented as a Google Maps web application.

METHODS

This was a retrospective study of all scene transports in Multnomah County, Oregon, from January 1 through December 31, 2008. Scene and destination hospital addresses were converted to coordinates. ArcGIS Network Analyst was used to estimate transport times based on street network speed limits. We then created a linear regression model to improve the accuracy of these street network estimates using weather, patient characteristics, use of lights and sirens, daylight, and rush-hour intervals. The model was derived from a 50% sample and validated on the remainder. Significance of the covariates was determined by p < 0.05 for a t-test of the model coefficients. Accuracy was quantified by the proportion of estimates that were within 5 minutes of the actual transport times recorded by computer-aided dispatch. We then built a Google Maps-based web application to demonstrate application in real-world EMS operations.

RESULTS

There were 48,308 included transports. Street network estimates of transport time were accurate within 5 minutes of actual transport time less than 16% of the time. Actual transport times were longer during daylight and rush-hour intervals and shorter with use of lights and sirens. Age under 18 years, gender, wet weather, and trauma system entry were not significant predictors of transport time. Our model predicted arrival time within 5 minutes 73% of the time. For lights and sirens transports, accuracy was within 5 minutes 77% of the time. Accuracy was identical in the validation dataset. Lights and sirens saved an average of 3.1 minutes for transports under 8.8 minutes, and 5.3 minutes for longer transports.

CONCLUSIONS

An estimate of transport time based only on a street network significantly underestimated transport times. A simple model incorporating few variables can predict ambulance time of arrival to the emergency department with good accuracy. This model could be linked to global positioning system data and an automated Google Maps web application to optimize emergency department resource use. Use of lights and sirens had a significant effect on transport times.

The trade-offs in field trauma triage: a multiregion assessment of accuracy metrics and volume shifts associated with different triage strategies

BACKGROUND

National benchmarks for trauma triage sensitivity (≥95%) and specificity (≥50%) have not been rigorously evaluated across broad populations of injured patients. We evaluated the impact of different field triage schemes for identifying seriously injured patients across a range of sensitivity values. Impact metrics included specificity and number of undertriaged and overtriaged patients compared with current triage practices.

METHODS

This was a retrospective cohort study of injured children and adults transported by 48 emergency medical service (EMS) agencies to 105 hospitals in 6 regions of the Western United States from 2006 through 2008. Hospital outcomes were probabilistically linked to EMS records through trauma registries, state discharge databases, and state emergency department databases. The primary outcome was an Injury Severity Score (ISS) of 16 or greater. We evaluated 40 field predictor variables, including 31 current field triage criteria, using classification and regression tree analysis and cross-validation to generate estimates for sensitivity and specificity.

RESULTS

A total of 89,261 injured patients were evaluated and transported by EMS providers during the 3-year period, of whom 5,711 (6.4%) had ISS of 16 or greater. As the 95% sensitivity target for triage was approached (from the current value of 87.5%), decision tree complexity increased, specificity decreased (from 62.8% to 18.7%), and the number of triage-positive patients without serious injury doubled (67,927 vs. 31,104). Analyses restricted to children and older adults were similar. The most consistent modification to the current triage algorithm to increase sensitivity without a major decrease in specificity was altering the Glasgow Coma Scale (GCS) score cutoff point from 13 or less to 14 or less (sensitivity increase to 90.4%).

CONCLUSION

Reaching the field triage sensitivity benchmark of 95% would require a large decrease in specificity (increase in overtriage). A 90% sensitivity target seems more realistic and may be obtainable by modest changes to the current triage algorithm.

End-of-life decision-making for patients admitted through the emergency department: hospital variability, patient demographics, and changes over time

BACKGROUND

Early studies suggest that racial, economic, and hospital-based factors influence the do-not-attempt-resuscitation (DNAR) status of admitted patients, although it remains unknown how these factors apply to patients admitted through the emergency department (ED) and whether use is changing over time.

OBJECTIVES

The objective was to examine patient and hospital attributes associated with DNAR orders placed within 24 hours of admission through the ED and changes in DNAR use over time.

METHODS

This was a population-based, retrospective cross-sectional study of patients 65 years and older admitted to 367 acute care hospitals in California between 2002 and 2010; the subset of patients admitted through the ED formed the primary sample. The primary outcome was placement of a DNAR order within 24 hours of admission. Associations between DNAR order placement and hospital characteristics, patient demographics, and year were tested. Descriptive statistics are reported, and multivariable logistic regression models with generalized estimating equations (GEEs) were used to account for clustering within hospitals.

RESULTS

There were 9,507,921 patients older than 65 years admitted to 367 California hospitals over the 9-year period, of whom 1,029,335 (10.8%) had DNAR orders placed within 24 hours of admission; 83% of DNAR orders were placed for patients admitted through the ED. Among patients over 65 years admitted through the ED (n = 6,396,910), DNAR orders were used less frequently at teaching hospitals (9.5% vs. 13.7%), for-profit hospitals (8.6% vs. 14.6% nonprofit), nonrural hospitals (12.0% vs. 26.2%), and large hospitals (11.1% vs. 15.0% for hospitals in the smallest quartile for bed size; all p < 0.0001). In regression modeling adjusted for clustering and patient demographics, these trends persisted for all hospital types, except teaching hospitals. Decreased DNAR frequency was associated with race (African American odds ratio [OR] = 0.59, 95% confidence interval [CI] = 0.51 to 0.67; Asian OR = 0.70, 95% CI = 0.59 to 0.82; reference = white), ethnicity (Hispanic OR = 0.61, 95% CI = 0.55 to 0.68), sex (male OR = 0.90, 95% CI = 0.88 to 0.92), and MediCal insurance (OR = 0.70, 95% CI = 0.57 to 0.85). Statewide rates of DNAR steadily increased from 12.2% in 2002 to 14.3% in 2010, although this trend occurred primarily among white and Asian patients.

CONCLUSIONS

While statewide rates of DNAR use have increased over time among patients admitted through the ED, there is variable penetrance of this practice by hospital types, patient race, and patient ethnicity. These patterns may suggest barriers to end-of-life discussions, differences in hospital case mix, and variation in cultural or institutional beliefs and practices.

Survival in out-of-hospital cardiac arrests with initial asystole or pulseless electrical activity and subsequent shockable rhythms

BACKGROUND

Non-shockable arrest rhythms (pulseless electrical activity and asystole) represent an increasing proportion of reported cases of out-of-hospital cardiac arrest (OHCA). The prognostic significance of conversion from non-shockable to shockable rhythms during the course of resuscitation remains unclear.

OBJECTIVE

To evaluate whether out-of-hospital cardiac arrest survival with initially non-shockable arrest rhythms is improved with subsequent conversion to shockable rhythms.

METHODS

Secondary analysis of data in Epistry - Cardiac Arrest, an epidemiologic registry maintained by the Resuscitation Outcomes Consortium (ROC). This analysis includes OHCA events from December 1, 2005 through May 31, 2007 contributed by six US and two Canadian sites. For all EMS-treated adult (18 and older) cardiac arrest patients who presented with non-shockable cardiac arrest, we compared survival to hospital discharge between patients who did develop a shockable rhythm and those who did not based on receipt of subsequent defibrillation. Missing data were handled using multiple imputation. Multivariable logistic regression was used to adjust for potentially confounding variables.

RESULTS

A total of 6556 EMS treated adult cardiac arrest cases presented in non-shockable rhythms. Survival to discharge in patients who converted to a shockable rhythm was 2.77% while survival in those who did not was 2.72% (p=0.92). After adjusting for confounders, conversion to a shockable rhythm was not associated with improved survival (OR 0.88, 95% CI: 0.60-1.30).

CONCLUSION

For OHCA patients presenting in PEA/asystole, survival to hospital discharge was not associated with conversion to a shockable rhythm during EMS resuscitation efforts.

Why persons choose to opt out of an exception from informed consent cardiac arrest trial

BACKGROUND

We sought to characterize persons who requested to opt out of an exception from informed consent (EFIC) cardiac arrest trial and their reasons for opting out.

METHODS

At one site of a multi-site, out-of-hospital, cardiac arrest EFIC trial (September 2007 - June 2009), persons who did not want to participate in the study could request an opt-out "NO STUDY" bracelet to prevent trial enrollment. We surveyed all persons who requested a bracelet by phone interview, web or mail. Opt-out bracelets were advertised in all public communication about the study, including community consultation and public disclosure efforts. Survey questions included demographics, Likert scale items about attitudes toward the trial and research in general, plus open-ended questions. We used descriptive statistics for standardized questions and qualitative analysis to identify common themes from open-ended questions.

RESULTS

Sixty bracelets were requested by 50 individuals. Surveys were completed by 46 persons (92% response rate). Seventy percent of respondents agreed emergency research is important, but 87% objected to any research without consent. In the qualitative analysis, 5 overlapping themes emerged: questioning the ethics of EFIC research; concerns about how the study would impact end-of-life preferences; subjective emotions including sarcasm, anger, and allusions to past unethical research; negative reference to unrelated public health controversies; and objections to the study protocol based on misinformation.

CONCLUSIONS

A primary reason for opting out from this EFIC trial was opposition to all research without informed consent, despite stated support for emergency research. Understanding the demographics and beliefs of persons opting out may aid researchers planning EFIC studies and help provide clarity in future EFIC-related community education efforts.

Establishing an emergency medicine education research network

This project was developed from the research network track at the 2012 Academic Emergency Medicine consensus conference on education research in emergency medicine (EM). Using a combination of consensus techniques, the modified Delphi method, and qualitative research methods, the authors describe multiple aspects of developing, implementing, managing, and growing an EM education research network. A total of 175 conference attendees and 24 small-group participants contributed to discussions regarding an education research network; participants were experts in research networks, education, and education research. This article summarizes relevant conference discussions and expert opinion for recommendations on the structure of an education research network, basic operational framework, site selection, leadership, subcommittees, guidelines for authorship, logistics, and measuring success while growing and maintaining the network.

Variability of ICU use in adult patients with minor traumatic intracranial hemorrhage

STUDY OBJECTIVE

Patients with minor traumatic intracranial hemorrhage are frequently admitted to the ICU, although many never require critical care interventions. To describe ICU resource use in minor traumatic intracranial hemorrhage, we assess (1) the variability of ICU use in a cohort of patients with minor traumatic intracranial hemorrhage across multiple trauma centers, and (2) the proportion of adult patients with traumatic intracranial hemorrhage who are admitted to the ICU and never receive a critical care intervention during hospitalization. In addition, we evaluate the association between ICU admission and key independent variables.

METHODS

A structured, historical cohort study of adult patients (aged 18 years and older) with minor traumatic intracranial hemorrhage was conducted within a consortium of 8 Level I trauma centers in the western United States from January 2005 to June 2010. The study population included patients with minor traumatic intracranial hemorrhage, defined as an emergency department (ED) Glasgow Coma Scale (GCS) score of 15 (normal mental status) and an Injury Severity Score less than 16 (no other major organ injury). The primary outcome measure was initial ICU admission. The secondary outcome measure was a critical care intervention during hospitalization. Critical care interventions included mechanical ventilation, neurosurgical intervention, transfusion of blood products, vasopressor or inotrope administration, and invasive hemodynamic monitoring. ED disposition and the proportion of ICU patients not receiving a critical care intervention were compared across sites with descriptive statistics. The association between ICU admission and predetermined independent variables was analyzed with multivariable regression.

RESULTS

Among 11,240 adult patients with traumatic intracranial hemorrhage, 1,412 (13%) had minor traumatic intracranial hemorrhage and complete ED disposition data (mean age 48 years; SD 20 years). ICU use within this cohort across sites ranged from 50% to 97%. Overall, 847 of 888 patients (95%) with minor traumatic intracranial hemorrhage who were admitted to the ICU did not receive a critical care intervention during hospitalization (range between sites 80% to 100%). Three of 524 (0.6%) patients discharged home or admitted to the observation unit or ward received a critical care intervention. After controlling for severity of injury (age, blood pressure, and Injury Severity Score), study site was independently associated with ICU admission (odds ratios ranged from 1.5 to 30; overall effect P<.001).

CONCLUSION

Across a consortium of trauma centers in the western United States, there was wide variability in ICU use within a cohort of patients with minor traumatic intracranial hemorrhage. Moreover, a large proportion of patients admitted to the ICU never required a critical care intervention, indicating the potential to improve use of critical care resources in patients with minor traumatic intracranial hemorrhage.

The impact of early do not resuscitate (DNR) orders on patient care and outcomes following resuscitation from out of hospital cardiac arrest

OBJECTIVES

Among patients successfully resuscitated from out-of-hospital cardiac arrest (OHCA) and admitted to California hospitals, we examined how the placement of a do not resuscitate (DNR) order in the first 24h after admission was associated with patient care, procedures and inhospital survival. We further analyzed hospital and patient demographic factors associated with early DNR placement among patients admitted following OHCA.

METHODS

We identified post-OHCA patients from a statewide California database of hospital admissions from 2002 to 2010. Documentation of patient and hospital demographics, hospital interventions, and patient outcome were analyzed by descriptive statistics and multiple regression models to calculate odds ratios and 95% confidence intervals.

RESULTS

Of 5212 patients admitted to California hospitals after resuscitation from OHCA, 1692 (32.5%) had a DNR order placed in the first 24h after admission. These patients had decreased frequency of cardiac catheterization (1.1% vs. 4.3%), blood transfusion (7.6% vs. 11.2%), ICD placement (0.1% vs. 1.1%), and survival to discharge (5.2% vs. 21.6%, all p-values<0.0001). There was wide intrahospital variability and significant racial differences in the adjusted odds of early DNR orders (Asian, OR 0.67, 95% CI 0.48-0.95; Black, OR 0.49, 95% CI 0.35-0.69).

CONCLUSIONS

Early DNR placement is associated with a decrease in potentially critical hospital interventions, procedures, and survival to discharge, and wide variability in practice patterns between hospitals. In the absence of prior patient wishes, DNR placement within 24h may be premature given the lack of early prognostic indicators after OHCA.

The association between hospital type and mortality among critically ill children in US EDs

STUDY AIM

Little is known about the setting of care for critically ill children and whether differences in outcomes are related to the presenting hospital type. This study describes the characteristics of hospitals to which critically ill children present and explores the associations between hospital factors and mortality.

METHODS

This is a retrospective cohort study using data from the 2007 Healthcare Cost and Utilization Project National Emergency Department Sample, representative of all US ED visits. Subjects include children aged 0-18 with ICD9 codes for cardiac arrest, respiratory arrest and/or respiratory failure. Predictor variables include: age, sex, presence of chronic illness, self-pay, public insurance, trauma diagnosis, major trauma center, urban hospital, ED volume and teaching hospital. Multivariate logistic regression estimates predictors of mortality. Analyses integrate clusters, strata, and weights from the probability sample.

RESULTS

There were an estimated 29 million pediatric ED visits in 2007 including 42,036 (0.1%) visits for cardiac or respiratory failure. Teaching hospitals (OR 0.57, 95% CI 0.50-0.66), trauma centers (OR 0.76, 95% CI 0.67-0.86), and urban hospitals (OR 0.78, 95% CI 0.63-0.97) were associated with lower mortality odds. Presence of a chronic illness (OR 14.5, 95% CI 10.5-20.1), diagnosis of an injury (OR 1.2, 95% CI 1.1-1.4) and self-pay status (OR 3.6, 95% CI 2.9-4.4) were associated with increased mortality odds.

CONCLUSIONS

The majority of children with cardiac and respiratory arrest present to urban teaching hospitals and trauma centers. After accounting for important confounders, mortality is lower at teaching hospitals and/or major trauma centers.