Systolic blood pressure below 110 mmHg is associated with increased mortality in penetrating major trauma patients: Multicentre cohort study
ABSTRACT Non-invasive systolic blood pressure (SBP) measurement is a commonly used triaging tool for trauma patients. A SBP of <90mmHg has represented the threshold for hypotension for many years, but recent studies have suggested redefining hypotension at lower levels. We therefore examined the association between SBP and mortality in penetrating trauma patients.
We conducted a prospective cohort study in adult (≥16 years) penetrating trauma patients. Patients were admitted to hospitals belonging to the Trauma Audit and Research Network (TARN) between 2000 and 2009. The main outcome measure was the association between SBP and mortality at 30 days. Multivariate logistic regression models adjusted for the influence of age, gender, Injury Severity Score (ISS) and Glasgow Coma Score (GCS) on mortality were used.
3444 patients with a median age of 30 years (IQR 22.5-41.4), SBP of 126mmHg (IQR 107-142), ISS of 9 (IQR 9-14) and GCS of 15 (IQR 15-15), were analysed. Multivariable logistic regression analysis adjusted for age, gender, severity of injury and level of consciousness showed a cut-off for SBP at <110mmHg, after which increased mortality was observed. Compared with the reference group with SBP 110-129mmHg, mortality was doubled at SBP 90-109mmHg, was four-fold higher at 70-89mmHg and 10-fold higher at <70mmHg. SBP values ≥150mmHg were associated with decreased mortality.
We recommend that penetrating trauma patients with a SBP<110mmHg are triaged to resuscitation areas within dedicated, appropriately specialised, high-level care trauma centres.
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ABSTRACT: Undertriage is a concern in geriatric patients. The National Trauma Triage Protocol (NTTP) recognized that systolic blood pressure (SBP) less than 110 mm Hg may represent shock in those older than 65 years. The objective was to evaluate the impact of substituting an SBP of less than 110 mm Hg for the current SBP of less than 90 mm Hg criterion within the NTTP on triage performance and mortality. Subjects undergoing scene transport in the National Trauma Data Bank (2010-2012) were included. The outcome of trauma center need was defined as Injury Severity Score (ISS) greater than 15, intensive care unit admission, urgent operation, or emergency department death. Geriatric (age > 65 years) and adult (age, 16-65 years) cohorts were compared. Triage characteristics and area under the curve (AUC) were compared between SBP of less than 110 mm Hg and SBP of less than 90 mm Hg. Hierarchical logistic regression was used to determine whether geriatric patients newly triaged positive under this change (SBP, 90-109 mm Hg) have a risk of mortality similar to those triaged positive with SBP of less than 90 mm Hg. There were 1,555,944 subjects included. SBP of less than 110 mm Hg had higher sensitivity but lower specificity in geriatric (13% vs. 5%, 93% vs. 99%) and adult (23% vs. 10%, 90% vs. 98%) cohorts. AUC was higher for SBP of less than 110 mm Hg individually in both geriatric and adult (p < 0.01) cohorts. Within the NTTP, the AUC was similar for SBP of less than 110 mm Hg and SBP of less than 90 mm Hg in geriatric subjects but was higher for SBP of less than 90 mm Hg in adult subjects (p < 0.01). Substituting SBP of less than 110 mm Hg resulted in an undertriage reduction of 4.4% with overtriage increase of 4.3% in the geriatric cohort. Geriatric subjects with SBP of 90 mm Hg to 109 mm Hg had an odds of mortality similar to those of geriatric patients with SBP of less than 90 mm Hg (adjusted odds ratio, 1.03; 95% confidence interval, 0.88-1.20; p = 0.71). SBP of less than 110 mm Hg increases sensitivity. SBP of less than 110 mm Hg has discrimination as good as that of SBP of less than 90 mm Hg, with superior improvements in undertriage relative to overtriage in geriatric patients. Geriatric patients newly triaged to be positive under this change have a risk of mortality similar to those under the current SBP criterion. This change in SBP criteria may be merited in geriatric patients, warranting further study to consider elevation to a Step 1 criterion in the NTTP. Diagnostic study, level IV.Journal of Trauma and Acute Care Surgery 02/2015; 78(2):352-359. DOI:10.1097/TA.0000000000000523 · 1.97 Impact Factor
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ABSTRACT: Recently, two simple clinical scores were published to predict survival in trauma patients. Both scores may successfully guide major trauma triage, but neither has been independently validated in a hospital setting. This is a cohort study with 30-day mortality as the primary outcome to validate two new trauma scores-Mechanism, Glasgow Coma Scale (GCS), Age, and Pressure (MGAP) score and GCS, Age and Pressure (GAP) score-using data from the UK Trauma Audit and Research Network. First, an assessment of discrimination, using the area under the receiver operating characteristic (ROC) curve, and calibration, comparing mortality rates with those originally published, were performed. Second, we calculated sensitivity, specificity, predictive values, and likelihood ratios for prognostic score performance. Third, we propose new cutoffs for the risk categories. A total of 79,807 adult (≥16 years) major trauma patients (2000-2010) were included; 5,474 (6.9%) died. Mean (SD) age was 51.5 (22.4) years, median GCS score was 15 (interquartile range, 15-15), and median Injury Severity Score (ISS) was 9 (interquartile range, 9-16). More than 50% of the patients had a low-risk GAP or MGAP score (1% mortality). With regard to discrimination, areas under the ROC curve were 87.2% for GAP score (95% confidence interval, 86.7-87.7) and 86.8% for MGAP score (95% confidence interval, 86.2-87.3). With regard to calibration, 2,390 (3.3%), 1,900 (28.5%), and 1,184 (72.2%) patients died in the low, medium, and high GAP risk categories, respectively. In the low- and medium-risk groups, these were almost double the previously published rates. For MGAP, 1,861 (2.8%), 1,455 (15.2%), and 2,158 (58.6%) patients died in the low-, medium-, and high-risk categories, consonant with results originally published. Reclassifying score point cutoffs improved likelihood ratios, sensitivity and specificity, as well as areas under the ROC curve. We found both scores to be valid triage tools to stratify emergency department patients, according to their risk of death. MGAP calibrated better, but GAP slightly improved discrimination. The newly proposed cutoffs better differentiate risk classification and may therefore facilitate hospital resource allocation. Prognostic study, level II.Journal of Trauma and Acute Care Surgery 11/2014; 77(5):757-763. DOI:10.1097/TA.0000000000000452 · 1.97 Impact Factor
Article: Understanding traumatic shockJournal of Trauma and Acute Care Surgery 01/2015; 78(2):342-351. DOI:10.1097/TA.0000000000000478 · 1.97 Impact Factor