The predictive value and appropriate ranges of prehospital physiological parameters for high-risk injured children

Strategies to Obtain and Deliver Blood Products Into Critically Injured Children: A Survey of Pediatric Trauma Society Members

OBJECTIVES

Timely transfusion is associated with improved survival and a reduction in in-hospital morbidity. The benefits of early hemorrhagic shock recognition may be limited by barriers to accessing blood products and their timely administration. We examined how pediatric trauma programs obtain blood products, the types of rapid infusion models used, and the metrics tracked to improve transfusion process efficiency in their emergency department (ED).

METHODS

We developed and distributed a self-report survey to members of the Pediatric Trauma Society. The survey consisted of 6 initial questions, including the respondent's role and institution, whether a blood storage refrigerator was present in their ED, the rapid infuser model used to transfuse critically injured children in their ED, if their program tracked 4 transfusion process metrics, and if a video recording system was present in the trauma bay. Based on these responses, additional questions were prompted with an option for a free-text response.

RESULTS

We received 137 responses from 77 institutions. Most pediatric trauma programs have a blood storage refrigerator in the ED (n = 46, 59.7%) and use a Belmont rapid infuser to transfuse critically injured children (n = 45, 58.4%). The American College of Surgeons Level 1 designated trauma programs, or state-based equivalents, and "pediatric" trauma programs were more likely to have video recording systems for performance improvement review compared with lower designated trauma programs and "combined pediatric and adult" trauma programs, respectively.

CONCLUSIONS

Strategies to improve the timely acquisition and infusion of blood products to critically injured children are underreported. This study examined the current practices that pediatric trauma programs use to transfuse critically injured children and may provide a resource for trauma programs to cite for transfusion-related quality improvement.

Evaluation of Missing Prehospital Physiological Values in Injured Children and Adolescents

INTRODUCTION

Prehospital vital signs and the Glasgow Coma Scale score are often missing in clinical practice and not recorded in trauma databases. Our study aimed to identify factors associated with missing prehospital physiological values, including systolic blood pressure, heart rate, respiratory rate, peripheral oxygen saturation, and Glasgow Coma Scale.

METHODS

We used our hospital trauma registry to obtain patient, injury, resuscitation, and transportation characteristics for injured children and adolescents (age <15 y). We evaluated the association of missing documentation of prehospital values with other patient, injury, transportation, and resuscitation characteristics using multivariable regression. We standardized vital sign values using age-adjusted z-scores.

RESULTS

The odds of a missing physiological value decreased with age (odds ratio [OR] = 0.9, 95% confidence interval [CI] = 0.9, 0.9) and were higher when prehospital cardiopulmonary resuscitation was required (OR = 3.3, 95% CI = 1.9, 5.7). Among the physiological values considered, we observed the highest odds of missingness of systolic blood pressure, respiratory rate, and oxygen saturation. The odds of observing normal emergency department physiological values were lower when prehospital physiological values were missing (OR = 0.9, 95% CI = 0.9, 1.0; P = 0.04).

CONCLUSIONS

Missing prehospital physiological values were associated with younger age and cardiopulmonary resuscitation among the injured children treated at our hospital. Measurement and documentation of physiological variables of patients with these characteristics should be targeted.

National guideline for the field triage of injured patients: Recommendations of the National Expert Panel on Field Triage, 2021

This work details the process of developing the updated field triage guideline, the supporting evidence, and the final version of the 2021 National Guideline for the Field Triage of Injured Patients.

Progression of vital signs during ambulance transport categorised by a paediatric triage model: a population-based historical cohort study

OBJECTIVES

To examine the severity and progression of acute illness or injury in children using vital signs obtained during ambulance transport and categorised according to a paediatric triage model.

DESIGN

A population-based historical cohort study using data from prehospital patient medical records linked to a national civil registration database.

SETTING

Emergency medical services providing ground-level transport in a mixed urban-rural region with three hospitals in Denmark.

PARTICIPANTS

25 039 events with patients aged <18 years attended by emergency medical services dispatched after a 1-1-2 emergency call during the years 2006-2018.

PRIMARY AND SECONDARY OUTCOME MEASURES

Distribution of the first observed vital signs according to a paediatric triage model: heart rate, Glasgow Coma Score, respiratory rate, oxygen saturation and oxygen treatment, and proportion of patients progressing to a triage score with a lower level of urgency during ambulance transport.

RESULTS

The proportion of patients with the first observed vital signs outside the normal age-specific range was as follows: 33.6% for heart rate, 15.3% for Glasgow Coma Score, 17.4% for respiratory rate and 37.4% for oxygen saturation regardless of oxygen treatment. The proportion of patients progressing to a triage score with a lower level of urgency during transport varied with age: 146/354 (41.2%) for age 0-2 months, 440/986 (44.6%) for age 3-11 months, 1278/3212 (39.8%) for age 1-2 years, 967/2814 (34.4%) for age 3-7 years and 4029/13 864 (29.1%) for age 8-17 years (p<0.001). One-day mortality was 3.05 deaths per 1000 patient-days (95% CI 2.43 to 3.83).

CONCLUSIONS

One third of the patients' condition progressed to a triage score with a lower level of urgency during ambulance transport. Vital sign documentation in paediatric patients was incomplete, and educational initiatives should be taken to increase documentation of vital signs, especially in patients aged ≤2 years.

Correlation of Level of Trauma Activation With Emergency Department Intervention

BACKGROUND

In-hospital trauma team activation criteria are formulated to identify severely injured patients requiring specialized multidisciplinary care. Efficacy of trauma activation (TA) criteria is commonly measured by emergency department (ED) disposition, injury severity score, and mortality. Necessity of critical ED interventions is another measure that has been proposed to evaluate the appropriateness of TA criteria.

METHODS

Two-year retrospective cohort study of 1715 patients from our trauma registry at a Level 1 pediatric trauma center. We abstracted data on acute interventions, level and criterion of TA, ED disposition, and mortality. We report odds ratio (OR) with 95% confidence intervals (CIs), positive predictive value, and frequency of acute interventions.

RESULTS

Trauma activation was initiated for 947 (55%) of the 1715 patients. There were 426 ED interventions performed on 235 patients (14%); 67.8% were in level 1 activations; 17.6% in level 2, and 14.6% in level 3. Highest-level activations were highly associated with need for ED interventions (OR, 16.1; 95% CI, 11.5-22.4). The ORs for requiring an ED intervention were low for lower level activations (OR, 0.4; 95% CI, 0.3-0.5), trauma service consults (OR, 0.3; 95% CI, 0.2-0.4), and certain mechanism-based criteria. The ORs for ED intervention for isolated motor vehicle collision (0.2; 95% CI, 0.1-0.7), isolated all-terrain vehicle rollover (0.4; 95% CI, 0.1-1.7), and suspected spinal cord injury (0.5; 95% CI, 0.1-3.7) were significantly lower than 1.

CONCLUSIONS

Highest-level activation criteria correlate with high utilization of ED resources and interventions. Lower level activation criteria and trauma service consult criteria are not highly correlated with need for ED interventions. Downgrading isolated motor vehicle collision and all-terrain vehicle rollovers and suspected spinal cord injury to lower level activations could decrease the overtriage rate, and adding age-specific bradycardia as a physiologic criterion could improve our undertriage rate.

The inter-rater reliability and prognostic value of coma scales in Nepali children with acute encephalitis syndrome

Background Acute encephalitis syndrome (AES) is a common cause of coma in Nepali children. The Glasgow coma scale (GCS) is used to assess the level of coma in these patients and predict outcome. Alternative coma scales may have better inter-rater reliability and prognostic value in encephalitis in Nepali children, but this has not been studied. The Adelaide coma scale (ACS), Blantyre coma scale (BCS) and the Alert, Verbal, Pain, Unresponsive scale (AVPU) are alternatives to the GCS which can be used. Methods Children aged 1-14 years who presented to Kanti Children's Hospital, Kathmandu with AES between September 2010 and November 2011 were recruited. All four coma scales (GCS, ACS, BCS and AVPU) were applied on admission, 48 h later and on discharge. Inter-rater reliability (unweighted kappa) was measured for each. Correlation and agreement between total coma score and outcome (Liverpool outcome score) was measured by Spearman's rank and Bland-Altman plot. The prognostic value of coma scales alone and in combination with physiological variables was investigated in a subgroup (n = 22). A multivariable logistic regression model was fitted by backward stepwise. Results Fifty children were recruited. Inter-rater reliability using the variables scales was fair to moderate. However, the scales poorly predicted clinical outcome. Combining the scales with physiological parameters such as systolic blood pressure improved outcome prediction. Conclusion This is the first study to compare four coma scales in Nepali children with AES. The scales exhibited fair to moderate inter-rater reliability. However, the study is inadequately powered to answer the question on the relationship between coma scales and outcome. Further larger studies are required.

A consensus-based criterion standard for trauma center need

BACKGROUND

In civilian trauma care, field triage is the process applied by prehospital care providers to identify patients who are likely to have severe injuries and immediately need the resources of a trauma center. Studies of the efficacy of field triage have used various measures to define trauma center need because no "criterion standard" exists, making cross-study comparisons difficult. This study aimed to develop a consensus-based functional criterion standard definition of trauma center need.

METHODS

Local and national experts were recruited for participation. Blinded key informant interviews were conducted in order of availability until no new themes emerged. Themes identified during the interviews were used to develop a Modified Delphi survey, which was electronically delivered via Survey Monkey. The trauma center need criteria were refined iteratively based on participant responses. Participants completed additional surveys until there was at least 80% agreement for each criterion.

RESULTS

Fourteen experts were recruited. Five participated in key informant interviews. A Modified Delphi survey was administered five times (four modifications based on the expert's responses). After the fifth round, there was at least 82% agreement on each criterion. The final definition included 10 time-specific indicators: major surgery, advanced airway, blood products, admission for spinal cord injury, thoracotomy, pericardiocentesis, cesarean delivery, intracranial pressure monitoring, interventional radiology, and in-hospital death.

CONCLUSION

We developed a consensus-based functional criterion standard definition of needing the resources of a trauma center, which may help to standardize field triage research and quality assurance in trauma systems as well as allow for cross study comparisons.

Prognostic value of shock index in children with septic shock

OBJECTIVES

Septic shock is frequent in children and is associated with high mortality and morbidity rates. Early recognition of severe sepsis improve outcome. Shock index (SI), ratio of heart rate (HR) and systolic blood pressure (SBP), may be a good noninvasive measure of hemodynamic instability that has been poorly studied in children. The aim of the study was to explore the usefulness of SI as an early index of prognosis for septic shock in children.

METHODS

The study was retrospective and performed in 1 pediatric intensive care unit at a university hospital. The following specific data were collected at 0, 1, 2, 4, and 6 hours after admission: HR and SBP for SI calculation and lactate concentration. Patients were divided into 2 groups according to their outcome (death/survival).

RESULTS

A total of 146 children admitted with septic shock between January 2000 and April 2010 were included. Shock index was significantly different between survivors and nonsurvivors at 0, 4, and 6 hours after admission (P = 0.02, P = 0.03, and P = 0.008, respectively). Age-adjusted SIs were different between survivors and nonsurvivors at 0 and 6 hours, with a relative risk of death at these time points of 1.85 (1.04-3.26) (P = 0.03) and 2.17 (1.18-3.96) (P = 0.01), respectively. Moreover, an abnormal SI both at admission and at 6 hours was predictive of death with relative risk of 1.36 (1.05-1.76).

CONCLUSIONS

In our population of children with septic shock, SI was a clinically relevant and easily calculated predictor of mortality. It could be a better measure of hemodynamic status than HR and SBP alone, allowing for the early recognition of severe sepsis.

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.

Age- and sex-specific normal values for shock index in National Health and Nutrition Examination Survey 1999-2008 for ages 8 years and older

PURPOSE

Shock index (SI), the ratio of heart rate to systolic blood pressure, has found to outperform conventional vital signs as a predictor of shock. Although age-specific vital sign norms are recommended in screening for shock, there are no reported age- or sex-specific norms for SI. Our primary goal was to report age- and sex-specific SI normal values for a nationally representative population 10 years and older by 5-year age groups. A secondary goal was to report SI normal values for children ages 8 to 19 years by 1-year age groups.

BASIC PROCEDURES

Weighted data from the National Health and Nutrition Examination Survey 1999-2008 data sets were used to generate age- and sex-specific percentile curves of SI for subjects 8 years and older.

MAIN FINDINGS

The primary analysis included 33906 subjects (101837 weighted) 10 years and older. The secondary analysis included 13393 subjects (37983 weighted) 8 to 19 years old. Normalized SI values for each percentile decreased with increasing age and were higher for females across all ages. The most commonly cited SI threshold of 0.9 exceeded the 97th percentile for males younger than 25 years and for females younger than 40 years.

CONCLUSIONS

This first report of age- and sex-specific normal values for SI indicates that SI norms vary by age and sex. Just as age-specific vital sign norms are recommended in screening for shock, our findings suggest that age- and sex-specific SI norms may be more effective in screening for shock than a single-value threshold.

Predictive value of initial Glasgow coma scale score in pediatric trauma patients

OBJECTIVE

The objective of this study was to determine the predictive value of the Glasgow coma scale (GCS) and the Glasgow motor component (GMC) for overall mortality, death on arrival, and major injury and the relationship between GCS and length of stay (LOS) in the emergency department (ED) and hospital.

METHODS

Records from the American College of Surgeons National Trauma Data Base from 2007 to 2009 were extracted. Patients 0 to 18 years old transported from a trauma scene with complete initial scene data were included. Statistical analysis, including construction of receiver-operator curves, determined the correlation between GCS, GMC, and the clinical outcomes of interest.

RESULTS

There were 104,035 records with complete data for analysis, including 3946 deaths. Mean patient age was 12.6 (SD, 5.5) years. Glasgow coma scale was predictive of overall mortality, with area under the receiver-operator curve (AUC) of 0.946 (95% confidence interval [CI], 0.941-0.951); death on arrival, with AUC of 0.958 (95% CI, 0.953-0.963); and risk of major injury, with AUC of 0.720 (0.715-0.724). Lower GCS scores were associated with shorter ED LOS and longer hospital stays (P <0.001, analysis of variance) except GCS 3, associated with shorter hospitalizations. For predicting overall mortality, the AUC for GMC was 0.940 (95% CI, 0.935-0.945), and for predicting major injury, the AUC was 0.681 (95% CI, 0.677-0.686).

CONCLUSIONS

For pediatric trauma victims, the GCS is predictive of mortality and injury outcomes, as well as both ED and hospital LOS, and has excellent prognostic accuracy. The GMC has predictive value for injury and mortality that is nearly equivalent to the full GCS.

Factors associated with the interfacility transfer of the pediatric trauma patient: implications for prehospital triage

OBJECTIVE

The goal of this study was to identify prehospital factors associated with increased likelihood of interfacility transfer of pediatric trauma patients. Such factors might serve as a basis for improvements in future field pediatric trauma triage guidelines.

METHODS

This was a retrospective cohort study of children aged 12 years or younger with blunt, penetrating, or thermal injuries who were transported by ground emergency medical services from the scene to the emergency department of a Level I, II, or III trauma center within the Denver metropolitan area from January 1, 2000, to December 31, 2008. Characteristics predicting subsequent interfacility transfer to a pediatric trauma center (PTC) were assessed.

RESULTS

A total of 1673 patients were included in the analysis. Variables hypothesized to be most commonly associated with interfacility transfer were age, sex, mechanism of injury, body region of injury, and Glasgow Coma Scale score. The cohort included 1079 males and 593 females. Logistic regression analysis yielded the following as significant predictors of transfer: younger age (odds ratio [OR], 1.19; 95% confidence interval [CI], 1.15-1.25), lower Glasgow Coma Scale score (OR, 1.08; 95% CI, 1.01-1.16), the presence of burns (OR, 37.52; 95% CI, 7.3-191.7), non-accidental trauma (OR, 6.09; 95% CI, 2.44-15.25), falls (OR, 1.62; 95% CI, 1.06-2.48), other motor vehicle-related incidents (OR, 2.37; 95% CI, 1.08-5.19), abdominal injury (OR, 5.39; 95% CI, 2.31-12.55), head/neck injury (OR, 7.89; 95% CI, 4.21-14.77), limb injury (OR, 5.31; 95% CI, 2.78-10.16), and multiple injuries (OR, 13.01; 95% CI, 5.0-33.8).

CONCLUSIONS

Factors highly associated with transfer of an injured child from a non-PTC to a PTC included younger age, burns, non-accidental trauma, head/neck injury, and multiple injuries in younger children. Further investigation is warranted to determine whether these factors may have applicability in future improvements in field pediatric trauma patient triage guidelines.

Pediatric trauma mortality by type of designated hospital in a mature inclusive trauma system

Background:

Previous studies have shown divergent results regarding the survival of injured children treated at pediatric trauma centers (PTC) and adult trauma centers (ATC).

Aims:

(1) To document, in a regionalized inclusive trauma system, at which level of trauma centers were the injured children treated and (2) to compare the in-hospital mortality over five levels of trauma care, ranging from pediatric level I trauma centers (PTC) to designated local trauma hospitals (level IV) for the whole study sample and for subgroups of severely injured children and head trauma.

Materials and Methods:

A retrospective analysis included data on 11,053 injured children (age ≤16 years) treated between April 1998 and March 2005 in 58 designated trauma hospitals in the province of Quebec, Canada. Multiple imputation was used to handle missing physiological data and multivariate logistic regression was used to compare mortality over levels of care.

Results:

PTC treated 52.2% of the children. Children treated at PTC were more often transferred from another hospital (73%) and were more severely injured. ATC level I, II, III and IV centers treated, respectively, 3.0%, 16.2%, 24.3% and 4.3% of children. Compared with children treated at a PTC, the risk of mortality was higher for children treated at each other ATC, i.e. level I (adjusted odds ratio [OR] = 3.1; 95% confidence interval [CI]: 1.3–7.5), level II (OR = 2.5; 95% CI: 1.3–5.0), level III (OR = 5.2; 95% CI: 2.1–13.1) and level IV (OR = 9.9; 95% CI: 2.4–41.3). Similar findings were observed among the subsamples of children who were more severely injured (Injury Severity Score >15) and who sustained head injuries.

Conclusions:

In our trauma system, PTC cared for more than half of the injured children and patients treated there have better survival than those treated at all other levels of ATC.

Validation of length of hospital stay as a surrogate measure for injury severity and resource use among injury survivors

OBJECTIVES

While hospital length of stay (LOS) has been used as a surrogate injury outcome when more detailed outcomes are unavailable, it has not been validated. This project sought to validate LOS as a proxy measure of injury severity and resource use in heterogeneous injury populations.

METHODS

This observational study used four retrospective cohorts: patients presenting to 339 California emergency departments (EDs) with a primary International Classification of Diseases, Ninth Revision (ICD-9), injury diagnosis (years 2005-2006); California hospital injury admissions (a subset of the ED population); trauma patients presenting to 48 Oregon EDs (years 1998-2003); and injured Medicare patients admitted to 171 Oregon and Washington hospitals (years 2001-2002). In-hospital deaths were excluded, as they represent adverse outcomes regardless of LOS. Duration of hospital stay was defined as the number of days from ED admission to hospital discharge. The primary composite outcome (dichotomous) was serious injury (Injury Severity Score [ISS] >or= 16 or ICD-9 ISS <or= 0.90) or resource use (major surgery, blood transfusion, or prolonged ventilation). The discriminatory accuracy of LOS for identifying the composite outcome was evaluated using receiver operating characteristic (ROC) analysis. Analyses were also stratified by age (0-14, 15-64, and >or=65 years), hospital type, and hospital annual admission volume.

RESULTS

The four cohorts included 3,989,409 California ED injury visits (including admissions), 236,639 California injury admissions, 23,817 Oregon trauma patients, and 30,804 Medicare injury admissions. Composite outcome rates for the four cohorts were 2.1%, 29%, 27%, and 22%, respectively. Areas under the ROC curves for overall LOS were 0.88 (California ED), 0.74 (California admissions), 0.82 (Oregon trauma patients), and 0.68 (Medicare patients). In general, the discriminatory value of LOS was highest among children, tertiary trauma centers, and higher volume hospitals, although this finding differed by the injury population and outcome assessed.

CONCLUSIONS

Hospital LOS may be a reasonable proxy for serious injury and resource use among injury survivors when more detailed outcomes are unavailable, although the discriminatory value differs by age and the injury population being studied.

The availability and use of out-of-hospital physiologic information to identify high-risk injured children in a multisite, population-based cohort

OBJECTIVE

The validity of using adult physiologic criteria to triage injured children in the out-of-hospital setting remains unproven. Among children meeting adult field physiologic criteria, we assessed the availability of physiologic information, the incidence of death or prolonged hospitalization, and whether age-specific criteria would improve the specificity of the physiologic triage step.

METHODS

We analyzed a prospective, out-of-hospital cohort of injured children aged < or =14 years collected from December 2005 through February 2007 by 237 emergency medical services (EMS) agencies transporting to 207 acute care hospitals (trauma and nontrauma centers) in 11 sites across the United States and Canada. Inclusion criteria were standard adult physiologic values: systolic blood pressure (SBP) < or =90 mmHg, respiratory rate < 10 or > 29 breaths/min, Glasgow Coma Scale (GCS) score < or =12, and field intubation attempt. Seven physiologic variables (including age-specific values) and three demographic and mechanism variables were included in the analysis. "High-risk" children included those who died (field or in-hospital) or were hospitalized > 2 days. The decision tree was derived and validated using binary recursive partitioning.

RESULTS

Nine hundred fifty-five children were included in the analysis, of whom 62 (6.5%) died and 117 (12.3%) were hospitalized > 2 days. Missing values were common, ranging from 6% (respiratory rate) to 53% (pulse oximetry), and were associated with younger age and high-risk outcome. The final decision rule included four variables (assisted ventilation, GCS score < 11, pulse oximetry < 95%, and SBP > 96 mmHg), which demonstrated improved specificity (71.7% [95% confidence interval (CI) 66.7-76.6%]) at the expense of missing high-risk children (sensitivity 76.5% [95% CI 66.4-86.6%]).

CONCLUSIONS

The incidence of high-risk injured children meeting adult physiologic criteria is relatively low and the findings from this sample do not support using age-specific values to better identify such children. However, the amount and pattern of missing data may compromise the value and practical use of field physiologic information in pediatric triage.

Paramedic determinations of medical necessity: a meta-analysis

INTRODUCTION

Reducing unnecessary ambulance transports may have operational and economic benefits for emergency medical services (EMS) agencies and receiving emergency departments. However, no consensus exists on the ability of paramedics to accurately and safely identify patients who do not require ambulance transport. Objective. This systematic review and meta-analysis evaluated studies reporting U.S. paramedics' ability to determine medical necessity of ambulance transport.

METHODS

PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Cochrane Library databases were searched using Cochrane Prehospital and Emergency Care Field search terms combined with the Medical Subject Headings (MeSH) terms "triage"; "utilization review"; "health services misuse"; "severity of illness index," and "trauma severity indices." Two reviewers independently evaluated each title to identify relevant studies; each abstract then underwent independent review to identify studies requiring full appraisal. Inclusion criteria were original research; emergency responses; determinations of medical necessity by U.S. paramedics; and a reference standard comparison. The primary outcome measure of interest was the negative predictive value (NPV) of paramedic determinations. For studies reporting sufficient data, agreement between paramedic and reference standard determinations was measured using kappa; sensitivity, specificity, and positive predictive value (PPV) were also calculated.

RESULTS

From 9,752 identified titles, 214 abstracts were evaluated, with 61 studies selected for full review. Five studies met the inclusion criteria (interrater reliability, kappa = 0.75). Reference standards included physician opinion (n = 3), hospital admission (n = 1), and a composite of physician opinion and patient clinical circumstances (n = 1). The NPV ranged from 0.610 to 0.997. Results lacked homogeneity across studies; meta-analysis using a random-effects model produced an aggregate NPV of 0.912 (95% confidence interval: 0.707-0.978). Only two studies reported complete 2 x 2 data: kappa was 0.105 and 0.427; sensitivity was 0.992 and 0.841; specificity was 0.356 and 0.581; and PPV was 0.158 and 0.823.

CONCLUSION

The results of the few studies evaluating U.S. paramedic determinations of medical necessity for ambulance transport vary considerably, and only two studies report complete data. The aggregate NPV of the paramedic determinations is 0.91, with a lower confidence limit of 0.71. These data do not support the practice of paramedics' determining whether patients require ambulance transport. These findings have implications for EMS systems, emergency departments, and third-party payers.

Establishing the need for trauma center care: anatomic injury or resource use?

OBJECTIVE

It remains unclear whether the "need" for care at a trauma center should be based on anatomic injury (the current standard) or specialized resource use. We investigated whether anatomic injury severity scores adequately explain hospital resource use.

METHODS

This was a retrospective cohort study including children and adults meeting statewide trauma criteria and transported to 48 hospitals from 1998 to 2003. The injury severity score (ISS) was considered as both continuous (range 0-75) and categorical (0-8, 9-15, and >or= 16) terms. Specialized resource use was defined as: major surgery (with and without orthopedic intervention), mechanical ventilation > 96 hours, blood transfusion, intensive care unit (ICU) stay >or= 2 days, or in-hospital mortality. Resource use was assessed as both a binary variable and a continuous term. Descriptive statistics and simple and multivariable linear regressions were used to compare ISS and resource use.

RESULTS

33,699 injured persons were included in the analysis. Within mild, moderate, and serious anatomic injury categories, 8%, 26%, and 69%, respectively, had specialized resource use. When the resource use definition included orthopedic surgery, 12%, 49%, and 76%, respectively, had specialized resource use. Whereas there was fair correlation between ISS and additive resource use (rho = 0.61), ISS explained only 37% of the variability in resource use (adjusted R-squared = 0.37). Resource use within anatomic injury categories differed by age group.

CONCLUSIONS

The standard anatomic injury criterion for trauma center "need" (i.e., ISS >or= 16) misclassifies a substantial number of injured persons requiring critical trauma resources. Out-of-hospital trauma triage guidelines based on anatomic injury may need revision to account for patients with resource need.

Paediatric coma scales

Traumatic and non-traumatic coma is a common problem in paediatric practice with high mortality and morbidity. Early recognition of the potential for catastrophic deterioration in a variety of settings is essential and several coma scales have been developed for recording depth of consciousness that are widely used in clinical practice in adults and children. Prediction of outcome is probably less important, as this may be able to be modified by appropriate emergency treatment, and other clinical and neurophysiological criteria allow a greater degree of precision. The scales should be reliable, i.e. with little variation between observers and in test-retest by one observer, since this promotes confidence in the assessments at different time points and by different examiners. This is particularly important when the patient is being assessed by personnel dealing with adults as well as children, discussed on the telephone, handed over at shift change, or transferred between units or hospitals. The British Paediatric Neurology Association has recommended one of the modified child's Glasgow coma scales (CGCS) for use in the UK. This review looks at the recent history of the development of coma scales and the rationale for recommending the CGCS.