Using Children's Artwork to Improve Adherence with Timely Antibiotic Administration in Open Fractures.

Introduction: Antibiotics for open fractures (OFs) administered within 60 min of emergency department (ED) arrival reduce patients' infection risk. We tested a novel method of displaying children's drawings to prompt clinicians to improve adherence with early antibiotics for OFs. Methods: Registry-based pre- (January 1, 2016-June 30, 2019) and post- (July 1, 2019-March 31, 2022) intervention at a level 1 trauma center. In July 2019, children's artwork depicting OF was displayed in the ED alongside OF guidelines and E-mailed to faculty and residents. Primary outcome: proportion of OF patients who received antibiotics within 60 min of arrival. Time to antibiotics was calculated from ED arrival to time-stamped administration in the electronic health record. We compared time to antibiotics as continuous variables between the two groups. Proportions are presented with percentages and 95% confidence interval (CI); continuous variables as median and quartiles. Chi-square or Mann-Whitney U-tests were used for group comparisons. Results: Five hundred fifty-four total OF patients were identified (excluded: transferred = 1, ED death = 4, unclear time to antibiotics = 11); 281 pre-implementation and 257 post-implementation. The median age was 34 years (quartiles 24 and 46). Trauma mechanisms of injury included 300 blunt (56%) and 238 penetrating (44%). Gustilo OF classification by type were as follows: 71% I, 13% II, 15% III, 1% unclassified. There was a significant difference (P = 0.001) in both percentage of patients who received antibiotics within 60 min (58%, 95% CI, 52%-63% vs. 79%, 95% CI, 74%-84%) and time to antibiotics (median: 46 min vs. 25 min) between pre- and postphases, respectively. Conclusions: Children's artwork in our ED improved adherence with OF guidelines and decreased time to antibiotics.

Computed tomography angiography for aerodigestive injuries in penetrating neck trauma: A systematic review.

OBJECTIVES: Management of hemodynamically stable patients with penetrating neck trauma (PNT) has evolved in recent years with improvements in imaging technology. Computed tomography angiography (CTA) encompassing all zones of the neck has become part of the standard diagnostic algorithm for PNT patients who do not require immediate surgical intervention for vascular or aerodigestive injuries (ADI). Several studies have demonstrated favorable operating characteristics for CTA at excluding arterial injuries; however, consensus as to CTA's ability to detect ADI is lacking. We conducted a systematic review (PROSPERO registration number CRD42019133509) to answer the question Is CTA sufficient to rule out ADI in hemodynamically stable PNT patients without hard signs? METHODS: Investigators independently searched PubMed, EMBASE, and Web of Science from their inception to August 2020 for the search terms "penetrating neck injuries" and "CT scan." To be included, studies required sufficient data to construct a 2×2 table of CTA for ADI. The operating characteristics of CTA for detecting ADIs are reported as sensitivity, specificity, and likelihood ratios (LRs), with 95% confidence intervals (95% CIs). Bias in our studies was quantified by QUADAS-2. RESULTS: Our search identified 1,242 citations with seven studies with moderate to high risk of bias meeting our inclusion/exclusion criteria and encompassing 877 subjects with an ADI prevalence of 13.4%. CTA for ADI had sensitivity of 92% (95% CI = 85% to 97%), specificity of 88% (95% CI = 85% to 90%), positive likelihood ratio of 12.2 (95% CI = 4.6 to 32), and negative LR of 0.14 (95% CI = 0.05 to 0.37). Of the 26 identified esophageal injuries across our studies that were diagnosed by either swallow studies or surgical exploration, five (19%, 95% CI = 8.1% to 38.3%) were initially missed by CTA. CONCLUSION: CTA alone is not sufficient to exclude esophageal injuries in PNT. Because delayed diagnosis is associated with increased morbidity, additional diagnostic interventions should be undertaken if there is remaining concern for esophageal injury.

Current topics in emergency trauma care: part 1: limiting radiation exposure in trauma imaging.

Increased diagnostic accuracy and widespread availability of computed tomography have enhanced initial trauma evaluation and facilitated nonoperative management of many types of injuries. However, concern that excessive radiation exposure could result in an increased lifetime cancer risk has prompted renewed evaluation of the potential risks and benefits of current diagnostic strategies. This supplement reviews best practices in diagnostic radiology for evaluation of the trauma patient and discusses approaches to optimize diagnostic assessment while limiting radiation exposure.

Evaluation and management of abdominal stab wounds: A Western Trauma Association critical decisions algorithm.

This is a recommended management algorithm from the Western Trauma Association addressing the management of adult patients with abdominal stab wounds. Because there is a paucity of published prospective randomized clinical trials that have generated Class I data, these recommendations are based primarily on published observational studies and expert opinion of Western Trauma Association members. The algorithm and accompanying comments represent a safe and sensible approach that can be followed at most trauma centers. We recognize that there will be patient, personnel, institutional, and situational factors that may warrant or require deviation from the recommended algorithm. We encourage institutions to use this as a guideline to develop their own local protocols.

Accuracy of Computed Tomography in Diagnosis of Intra-abdominal Injuries in Stable Patients With Anterior Abdominal Stab Wounds: A Systematic Review and Meta-analysis.

BACKGROUND: Workup for patients presenting to the emergency department (ED) following an anterior abdominal stab wound (AASW) has been debated since the 1960s. Experts agree that patients with peritonitis, evisceration, or hemodynamic instability should undergo immediate laparotomy (LAP); however, workup of stable, asymptomatic or nonperitoneal patients is not clearly defined. OBJECTIVES: The objective was to evaluate the accuracy of computed tomography of abdomen and pelvis (CTAP) for diagnosis of intraabdominal injuries requiring therapeutic laparotomy (THER-LAP) in ED patients with AASW. Is a negative CT scan without a period of observation sufficient to safely discharge a hemodynamically stable, asymptomatic AASW patient? METHODS: We searched PubMed, Embase, and Scopus from their inception until May 2017 for studies on ED patients with AASW. We defined the reference standard test as LAP for patients who were managed surgically and inpatient observation in those who were managed nonoperatively. In those who underwent LAP, THER-LAP was considered as disease positive. We used the Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2) to evaluate the risk of bias and assess the applicability of the included studies. We attempted to compute the pooled sensitivity, specificity, positive likelihood ratio (LR+), and negative likelihood ratio (LR-) using a random-effects model with MetaDiSc software and calculate testing and treatment thresholds for CT scan applying the Pauker and Kassirer model. RESULTS: Seven studies were included encompassing 575 patients. The weighted prevalence of THER-LAP was 34.3% (95% confidence interval [CI] = 30.5%-38.2%). Studies had variable quality and the inclusion criteria were not uniform. The operating characteristics of CT scan were as follows: sensitivity = 50% to 100%, specificity = 39% to 97%, LR+ = 1.0 to 15.7, and LR- = 0.07 to 1.0. The high heterogeneity (I2  > 75%) of the operating characteristics of CT scan prevented pooling of the data and therefore the testing and treatment thresholds could not be estimated. DISCUSSION: The articles revealed a high prevalence (8.7%, 95% CI = 6.1%-12.2%) of injuries requiring THER-LAP in patients with a negative CT scan and almost half (47%, 95% CI = 30%-64%) of those injuries involved the small bowel. CONCLUSIONS: In stable AASW patients, a negative CT scan alone without an observation period is inadequate to exclude significant intraabdominal injuries.

Clinical value of triage lactate in risk stratifying trauma patients using interval likelihood ratios.

Emergency physicians face the challenge of rapidly identifying high-risk trauma patients. Lactate (LAC) is widely used as a surrogate of tissue hypoperfusion. However, clinically important values for LAC as a predictor of mortality are not well defined. OBJECTIVES: 1. To assess the value of triage LAC in predicting mortality after trauma. 2. To compute interval likelihood ratios (LR) for LAC. METHODS: Retrospective chart review of trauma patients with a significant injury mechanism that warranted labs at an urban trauma center. OUTCOME: In-hospital mortality. Data are presented as median and quartiles or percentages with 95% confidence intervals. Groups (lived vs. died) were compared with Man-Whitney-U or Fisher's-exact test. Multivariate analysis was used to measure the association of the independent variables and mortality. The interval likelihood ratios were calculated for all LAC observed values. RESULTS: 10,575 patients; median age: 38 [25-57]; 69% male; 76% blunt; 1.1% [n=119] mortality. LAC was statistically different between groups in univariate (2.3 [1.6,3.0] vs 2.8 [1.6,4.8], p=0.008) and multivariate analyses (odds ratio: 1.14 [1.08-1.21], p=0.0001). Interval ratios for LR- ranged from 0.6-1.0. Increasing LAC increased LR+. However, LR+ for LAC reached 5 with LAC>9mmol/L and passed 10 (moderate and conclusive increase in disease probability, respectively) with LAC>18mmol/L. CONCLUSIONS: In a cohort of trauma patients with a wide spectrum of characteristics triage LAC was statistically able to identify patients at high risk of mortality. However, clinically meaningful contribution to decision-making occurred only at LAC>9. LAC was not useful at excluding those with a low risk of mortality.

Correlation of Venous Lactate and Time of Death in Emergency Department Patients with Noncritical Lactate Levels and Mortality from Trauma.

BACKGROUND: Serum venous lactate (LAC) levels help guide emergency department (ED) resuscitation of patients with major trauma. Critical LAC level (CLAC, ≥4.0 mmol/L) is associated with increased disease severity and higher mortality in injured patients. The characteristics of injured patients with non-CLAC (NCLAC) (<4.0 mmol/L) and death have not been previously described. OBJECTIVES: (1) To describe the characteristics of patients with venous NCLAC and death from trauma. (2) To assess the correlation of venous NCLAC with time of death. METHODS: A retrospective cohort study at an urban teaching hospital between 9/2011 and 8/2014. Inclusion: All trauma patients (all ages) who presented to the ED with any injury and met all criteria: (1) Venous LAC drawn at the time of arrival that resulted in an NCLAC level; (2) were admitted to the hospital; (3) died during their hospitalization. Exclusion: CLAC. Outcome: Correlation of NCLAC and time of death. Data were extracted from an electronic medical record by trained data abstractors using a standardized protocol. Cross-checks were performed on 10% of data entries and inter-observer agreement was calculated. Data were explored using descriptive statistics and Kaplan-Meier curves were created to define survival estimates. Data are presented as percentages with 95% confidence interval (CI) for proportions and medians with quartiles for continuous variables. Kaplan-Meier curves with differences in time to events based on LAC are used to analyze the data. RESULTS: A total of 60 patients met the inclusion criteria. The median age was 52 years (quartiles: 30, 75) and 73% were male (age range 2-92). The median LAC in the overall cohort was 1.9 mmol/L (quartiles: 1.5, 2.1). Sixteen patients (27%) died during the first 24 h with 5 (31%) due to intracranial hemorrhage. The median survival time was 5.6 days (134.4 h) (95% CI: 2.3-12.6). CONCLUSIONS: In trauma patients with NCLAC who died during the index hospitalization, the median survival time was 5.6 days, approximately one-third of patients died within the first 24 h. These findings indicate that relying on a triage NCLAC level alone may result in underestimating injury severity and subsequent morbidity and mortality.

The prognostic role of non-critical lactate levels for in-hospital survival time among ED patients with sepsis.

OBJECTIVE: This study describes emergency department (ED) sepsis patients with non-critical serum venous lactate (LAC) levels (LAC <4.0 mmol/L) who suffered in-hospital mortality and examines LAC in relation to survival times. METHODS: An ED based retrospective cohort study accrued September 2010 to August 2014. Inclusion criteria were ED admission, LAC sampling, >2 systemic inflammatory response syndrome criteria with an infectious source (sepsis), and in-hospital mortality. Kaplan-Meier curves were used for survival estimates. An a priori sub-group analysis for patients with repeat LAC within 6 hours of initial sampling was undertaken. The primary outcome was time to in-hospital death evaluated using rank-sum tests and regression models. RESULTS: One hundred ninety-seven patients met inclusion criteria. Pulmonary infections were the most common (44%) and median LAC was 1.9 mmol/L (1.5, 2.5). Thirteen patients (7%) died within 24 hours and 79% by ≤28 days. Median survival was 11 days (95% CI, 8.0-13). Sixty-two patients had repeat LAC sampling with 14 (23%) and 48 (77%) having decreasing increasing levels, respectively. No significant differences were observed in treatment requirements between the LAC subgroups. Among patients with decreasing LAC, median survival was 24 days (95% CI, 5-32). For patients with increasing LAC median survival was significantly shorter (7 days; 95% CI, 4-11, P = .04). Patients with increasing LAC had a non-significant trend toward reduced survival (HR = 1.6 95% CI, 0.90-3.0, P = .10). CONCLUSIONS: In septic ED patients experiencing in-hospital death, non-critical serum venous lactate may be utilized as a risk-stratifying tool for early mortality, while increasing LAC levels may identify those in danger of more rapid deterioration.

Utility of base deficit for identifying major injury in elder trauma patients.

BACKGROUND: Early identification of serious injuries is especially important in elders. Base deficit (BD) is an indicator of serious injury in trauma patients. There are limited data to support the utility of BD in elders who have sustained trauma. OBJECTIVES: To assess the diagnostic performance of BD in identifying major injury in elders. METHODS: This was a prospective, observational, preliminary study. Elder (age 65 years and older) patients with significant injury mechanisms had BD analyzed during initial emergency department resuscitation. Major injury was defined by an Injury Severity Score > or =15, a decrease in hematocrit of more than ten points, or blood transfusion. Patients were stratified into two groups of minor and major injuries. Data were reported as means (+/-SD). Receiver operating characteristic (ROC) curves tested the diagnostic ability of BD to identify major injury. RESULTS: Seventy-four patients were enrolled; the mean (+/-SD) age was 75 (+/-7) years, and 57% were male. Twenty-four patients (32%) had major injury. The mean (+/-SD) for BD in the major injury group (-2.9 [+/-6] mmol/L) was significantly different from that in the minor injury group (0.8 [+/-3] mmol/L), with a mean difference of 3.7 (95% confidence interval = 1.4 to 5.9). ROC curves revealed that BD was able to identify major injury in elder patients (area under the ROC curve, 0.72; 95% confidence interval = 0.60 to 0.85; p = 0.0003). CONCLUSIONS: The preliminary data from this study indicate that in trauma patients aged 65 years and older, increased BD at emergency department arrival can predict life-threatening injury.

Sublingual capnometry for rapid determination of the severity of hemorrhagic shock.

BACKGROUND: Sublingual capnometry (SLCO2) is a rapid, minimally invasive bedside test of focal tissue perfusion. We hypothesized that SLCO2 could diagnose hemorrhagic shock and monitor adequacy of resuscitation. We compared the ability of SLCO2, serum lactate (LAC), and base deficit (BD) to predict outcome in hypotensive trauma patients. METHODS: Prospective, observational trial at two Level I trauma centers was performed. Inclusion criteria were blunt or penetrating trauma patients, age > or =16 years, with hypotension (systolic blood pressure < or =90 mm Hg). SLCO2, LAC, and BD were measured in each patient at admission, at the end of active hemorrhage, and at 6, 24, and 48 hours. Data are reported as means (+/-SD). RESULTS: A total of 86 patients were enrolled: mean age 35 (+/-17) years, 80% male, 51% blunt trauma, Injury Severity Score score 20 (+/-14). Twenty patients died. SLCO2 at admission was 52.4 (+/-13.3) in survivors versus 87.9 (+/-35.6) in nonsurvivors (p < 0.001). Receiver operating characteristic (ROC) curves showed that SLCO2, LAC, and BD were all good predictors of mortality. The area under each ROC curve was as follows: SLCO2 (0.82; 95% CI 0.70-0.96; p < 0.001), LAC (0.80; 95% CI 0.69-0.91; p < 0.001), BD (0.87; 95% CI 0.77-0.98; p < 0.001). There was no significant difference (p > 0.05) in the areas under the three curves. CONCLUSIONS: SLCO2 predicted survival in hypotensive trauma patients. It had equivalent diagnostic ability to LAC and BD. This rapid test may supplement standard, more invasive measures of hemorrhagic shock.

The effect of non-insulin dependent diabetes mellitus on uncontrolled hemorrhage in a rodent model.

OBJECTIVE: Diabetes mellitus (DM) is an independent risk factor for higher morbidity and mortality rates from trauma. We tested the null hypothesis that there would be no difference in the hemorrhage volumes and hemodynamic responses to uncontrolled hemorrhage between Zucker Diabetic Fat rats (ZDF) and euglycemic Sprague-Dawley rats (SD). METHODS: Twenty-four adult male rats (12 ZDF and 12 SD) were anesthetized with althesin via the intraperitoneal route. The femoral artery was cannulated by cut-down to monitor the heart rate (HR), mean arterial pressure (MAP) and to obtain blood samples for blood gas analysis. Twelve rats (6 ZDF and 6 SD) underwent uncontrolled hemorrhage by 50% tail amputation. Twelve rats (6 ZDF and 6 SD) served as non-hemorrhage controls. The HR, MAP, lactate (LAC), glucose levels (GL) and cumulative hemorrhage volume (CHV) were measured pre-hemorrhage and then every 15 min post-hemorrhage for 120 min. Data were reported as mean+/-S.E.M. Group comparisons were analyzed by ANOVA with repeated values; post hoc testing by Bonferroni (all tests were two-tailed, alpha = 0.05). RESULTS: Pre-hemorrhage the SD and ZDF were evenly matched for LAC, HR and MAP. CHV (cm3/100 g) was significantly (p = 0.008) greater in the ZDF (1.49+/-0.12) as compared to the SD (0.38+/-0.11). The ZDF had significantly (p < 0.001) higher LAC (7.96+/-0.61 mmol/L) than the SD (2.0+/-0.41 mmol/L). CONCLUSION: DM as compared to non-DM rats suffered a greater blood loss with a more severe lactic acidosis after a comparable uncontrolled vascular injury.

Does ethanol explain the acidosis commonly seen in ethanol-intoxicated patients?

OBJECTIVE: Emergency physicians frequently treat ethanol-intoxicated trauma patients. In patients with apparently minor injuries, the presence of metabolic acidosis is often attributed to serum ethanol. We tested whether there is justification for the bias that ethanol reliably explains the acidosis commonly seen in alcohol-intoxicated patients. METHODS: Prospective, observational. INCLUSION CRITERIA: Ethanol-intoxicated patients admitted to the emergency department (ED) following significant trauma mechanisms, in whom diagnostic evaluation revealed only minor injury. EXCLUSION CRITERIA: Major trauma (blood transfusions, drop in Hct > 10 points over 24 h, or Injury Severity Score [ISS] >5) or positive urine toxicology screen. DEFINITIONS: Ethanol Intoxication: (Blood Alcohol Level (BAL) > or =80 mg/dl), Acidosis: BD < or = -3.0 mMol/L; Lactic Acidosis (LAC >2.2 mMol/L). Data were reported as mean+/-SD. Data were compared by t-tests or Fishers exact test as appropriate (alpha= 0.05, 2 tails) and correlations by Pearson correlation coefficient. RESULTS: 192 patients were studied (84% male) with a mean age of 31.7+/-15.6 years. Acidosis was observed in 19.3% (CI 95%, 14.5% to 25.0%) of all study patients. We observed significant (p<0.001) difference in prevalence of acidosis in ethanol intoxicated (42%) compared to nonintoxicated (1%) patients. Comparing the two study groups, patients with ethanol intoxication had lower BD (-2.24+/-2.74 vs. -0.05+/-2.35, p<0.001) and higher LAC (2.69+/-1.48 vs. 2.00+/-1.78, p=0.02). However, ethanol levels did not correlate significantly with BD (p=0.50) or LAC (p=0.14). CONCLUSION: Ethanol intoxication is associated with acidosis, which does not correlate with BD or LAC. The complexity of pathogenesis of acidosis in ethanol intoxication justifies further diagnostic evaluation of these patients in order to rule out other causes of acidosis.

Ethanol and illicit drugs do not affect the diagnostic utility of base deficit and lactate in differentiating minor from major injury in trauma patients.

OBJECTIVES: Base deficit (BD) and lactate are valuable screening tools for injured patients. They reflect the degree of oxygen debt and have been shown to predict outcome. Intake of ethanol and illicit drugs may further derange acid-base status. The authors evaluated the effect of blood alcohol level (BAL) and illicit drugs on admission BD and lactate levels in trauma patients. METHODS: Prospective, observational study of trauma patients in a Level 1 trauma center. Patients with penetrating or blunt trauma were included in the study. Patients were further stratified into major or minor categories. Major was defined by an Injury Severity Score >15, blood transfusions, or a decrease in hematocrit of more than ten points. Injury categories were further divided into several subgroups based on presence or absence of ethanol (BAL > or =0.08 g/dL) or positive urine toxicology screen (Utox). RESULTS: A total of 520 patients (84% male) with a mean (+/-SD) age of 33 (+/-15) years were studied. Compared with the minor injury categories, BD and lactate levels were significantly higher in the major injury categories in all different intoxication subgroups. Testing the diagnostic performance of BD and lactate in detecting major injury, the authors observed significant (p < 0.05) differences between the areas under the receiver operating characteristic curves for these two diagnostic tests compared with baseline in both intoxicated (BAL > or =0.08 g/dL and/or positive Utox) and nonintoxicated (BAL <0.08 g/dL and negative Utox) patients. CONCLUSIONS: The presence of ethanol and/or illicit drugs did not affect the ability of BD or lactate to identify patients with major injuries.

Diagnostic utility of sublingual PCO2 for detecting hemorrhage in penetrating trauma patients.

BACKGROUND: Hemorrhage results in early compromise of splanchnic circulation. Studies have shown that sublingual Pco2 (SLCO2) correlates with gut perfusion. We tested SLCO2's ability to detect hemorrhage. We compared SLCO2 with arterial base deficit (BD) and lactate (LAC). METHODS: This was a prospective study of patients with penetrating torso trauma. SLCO2 was measured at triage. Blood loss was defined as none (group 1), minimal to moderate (<1,500 mL) (group 2), or severe (>/=1,500 mL) (group 3). Data were reported as mean (95% confidence interval) and compared by analysis of variance. Receiver operating characteristic curves compared diagnostic performance between SLCO2, BD, and LAC. RESULTS: One hundred eight patients were enrolled. There was a significant difference (p < 0.001) in SLCO2 between all blood loss groups: group 1, 46.9 mm Hg (44.9-49.0 mm Hg); group 2, 53.5 mm Hg (50.8-56.2 mm Hg); and group 3, 66.0 mm Hg (53.1-78.9 mm Hg). There were no significant (p > 0.05) differences for receiver operating characteristic curves between SLCO2, BD, or LAC. CONCLUSION: SLCO2 differentiated blood loss groups. SLCO2 may be useful in triage of penetrating trauma patients.

Necessity of hospital admission for pediatric minor head injury.

The objective of this study was to evaluate the need for mandatory hospital admission of all pediatric patients with minor head injury (MHI) and negative computed tomographic (CT) scans for head injury. The study was a retrospective chart review of all patients admitted to a pediatric trauma service over a period of 4 years. MHI was defined as blunt head trauma with a Glasgow Coma Scale (GCS) score of 15 and a nonfocal neurological examination. Only patients < or = 13 years of age and with a negative head CT scan were included, and during hospitalization all patients were observed for delayed complications. A total of 197 patients met the inclusion criteria. The patients' mean age was 7.1 years, with a range of 2 months to 13 years. The most common mechanisms of injury were being struck by a motor vehicle while walking (82 patients), and falling (75 patients). No complications were observed, and although persistent symptoms occurred in 5 patients, they did not delay discharge. We conclude that pediatric patients with MHI and negative CT scans of the head do not require routine admission for observation for delayed complications.

The effect of hypertension on uncontrolled hemorrhage in a rodent model.

UNLABELLED: Patients with essential hypertension (EH) have higher mortality rates from hemorrhage. How the complex physiologic changes seen in EH affect the response to uncontrolled hemorrhage has yet to be adequately described. OBJECTIVE: To test the null hypothesis that there would be no difference in the hemorrhage volumes and hemodynamic responses to uncontrolled hemorrhage between hypertensive rats (SHRs) and normotensive rats (WKYs). METHODS: Twenty-four adult rats (12 WKYs and 12 SHRs) were anesthetized with althesin via the intra-peritoneal route. The femoral artery was cannulated by cutdown for mean arterial pressure (MAP) measurement and blood gas sampling. Twelve rats (6 WKYs and 6 SHRs) underwent uncontrolled hemorrhage by 50% tail amputation. Twelve rats (6 WKYs and 6 SHRs) served as non-hemorrhage controls. The MAP, base excess (BE), and cumulative blood loss were measured pre-hemorrhage and then every 15 minutes post-hemorrhage for 90 minutes. Data were reported as mean +/- standard error of the mean. Comparisons between control and uncontrolled hemorrhage groups were analyzed by analysis of variance (ANOVA) with repeated-measures post-hoc testing by Bonferroni. Statistical significance was defined by an alpha = 0.05. RESULTS: Mortality rates were significantly higher (p < 0.05) for the SHRs (100%) as compared with the WKYs (33%). Changes in time-averaged MAP post-hemorrhage were significantly greater (p < 0.001) in the SHR group (88 +/- 10 mm Hg) as compared with the WKY group (48 +/- 4 mm Hg). Hemorrhage volume was significantly lower (p = 0.02) in the SHR group (3.7 +/- 0.5 mL) as compared with the WKY group (6.1 +/- 0.7 mL). CONCLUSIONS: Hypertensive rats had a higher mortality rate than normotensives from a comparable vascular injury with lower hemorrhage volumes.