Paul A. MacLennan

Preexisting conditions and mortality in older trauma patients.

BACKGROUND Among older trauma patients, those with preexisting chronic medical conditions (CMCs) appear to have an elevated risk of death. Whether this association is dependent on the severity of injury or other occult factors remains unanswered. This study evaluated the association between preexisting CMCs and risk of death among older trauma patients according to injury severity. METHODS This was a retrospective cohort study using data from the National Trauma Data Bank, a registry of trauma patients admitted to 131 trauma centers across the United States. The main outcome measure was in-hospital mortality. RESULTS In patients 50 to 64 years of age who sustain severe (Injury Severity Score [ISS] of 26+) and moderate injuries (ISS of 16-25), the presence of one or more CMCs is not associated with an increased relative risk (RR) of death (RR, 0.80 and 95% confidence interval [CI], 0.71-0.90; RR, 1.09 and 95% CI, 0.95-1.24, respectively). Those with minor injuries (ISS < 16) have increased risk of death (RR, 2.80; 95% CI, 2.33-3.36). For those patients 65 years of age and older who sustain severe, moderate, and minor injuries, the pattern of results is similar (RR, 0.91 and 95% CI, 0.83-1.00; RR, 1.13 and 95% CI, 1.04-1.23; and RR, 1.88 and 95% CI, 1.73-2.05, respectively). CONCLUSION Older trauma patients with CMCs who present with minor injuries should be considered to have an increased risk of death when compared with their nonchronically ill counterparts.

Cancer Incidence Among Triazine Herbicide Manufacturing Workers

This study evaluated cancer incidence and prostate specific antigen (PSA) testing among workers at a plant in Louisiana (LA) that made atrazine and other triazine herbicides. The study covered the time period 1985 through 1997 and included 2045 subjects, of whom 757 worked for the company that owned the plant and 1288 were contract employees. Linkage with a population-based cancer registry and review of death certificates and plant medical records identified cancer cases. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) compared subjects’ cancer incidence rates with those of a regional general population. Plant medical records provided data on the proportion receiving PSA tests among male company employees. Subjects had 46 observed and 40 expected cases of all cancers combined (SIR = 114, CI = 83–152) and had 11/6.3 prostate cancers (SIR = 175, CI = 87–312). The prostate cancer excess was greater in actively working company employees (5/1.3, SIR = 394, CI = 128–920) than in contract employees or inactive company employees (6/5.0, SIR = 119, CI = 44–260) and was limited to men under 60 years of age. Of the 11 prostate cancer cases, nine were diagnosed at an early clinical stage. From 1993 to 1999, the proportion of male company employees who had at least one PSA test was 86% for those who reached 40 years of age while actively working and was 98% for those who reached 45 years of age. The observed prostate cancer increase may have been due to the frequent PSA testing of actively working company employees. There is no epidemiologic or other information that clearly supports a causal relation between atrazine and prostate cancer.

Stress-induced hyperglycemia, not diabetic hyperglycemia, is associated with higher mortality in trauma.

Objectives:To identify all trauma patients with diabetes and compare diabetic hyperglycemia (DH) patients with those with stress-induced hyperglycemia (SIH). Background:SIH has been shown to result in worse outcomes after trauma. The presence of diabetes mellitus (DM) or occult DM within the cohort confounded previous studies. We identified 2 distinct populations of trauma patients with SIH or DH to determine the impact of hyperglycemia on these 2 groups. Methods:Admission glycosylated hemoglobin (HbA1c), glucose levels, and comorbidity data were collected over a 2-year period. DM was determined by patient history or admission HbA1c 6.5% or more. SIH was determined by absence of DM and admission glucose 200 mg/dL or more. Cox proportional hazards models [adjusted for age, sex, injury mechanism, and injury severity score] were used to calculate risk ratios (RRs) and associated 95% confidence intervals (CIs) for outcomes of interest. Results:During the study period, 6852 trauma patients were evaluated, and 5117 had available glucose, HbA1c, and comorbidity data. Patients with SIH had an over twofold increase in mortality risk (RR 2.41, 95% CI 1.81–3.23), and patients with DH had a nonsignificant, near-50% increase in mortality risk (RR 1.47, 95% CI 0.92–2.36). Risk of pneumonia was similarly higher for both the DH (RR 1.49, 95% CI 1.03–2.17) and the SIH (RR 1.44, 95% CI 1.08–1.93). Conclusions:DM is common in patients with hyperglycemia after trauma. As opposed to DH, SIH is associated with higher mortality after trauma. Further research is warranted to identify mechanisms causing hyperglycemia and subsequent worse outcomes after trauma.

A National Study of Outcomes among HIV-Infected Kidney Transplant Recipients

Kidney transplantation is a viable treatment for select patients with HIV and ESRD, but data are lacking regarding long-term outcomes and comparisons with appropriately matched HIV-negative patients. We analyzed data from the Scientific Registry of Transplant Recipients (SRTR; 2002-2011): 510 adult kidney transplant recipients with HIV (median follow-up, 3.8 years) matched 1:10 to HIV-negative controls. Compared with HIV-negative controls, HIV-infected recipients had significantly lower 5-year (75.3% versus 69.2%) and 10-year (54.4% versus 49.8%) post-transplant graft survival (GS) (hazard ratio [HR], 1.37; 95% confidence interval [95% CI], 1.15 to 1.64; P<0.001) that persisted when censoring for death (HR, 1.43; 95% CI, 1.12 to 1.84; P=0.005). However, compared with HIV-negative/hepatitis C virus (HCV)-negative controls, HIV monoinfected recipients had similar 5-year and 10-year GS, whereas HIV/HCV coinfected recipients had worse GS (5-year: 64.0% versus 52.0%, P=0.02; 10-year: 36.2% versus 27.0%, P=0.004 [HR, 1.38; 95% CI, 1.08 to 1.77; P=0.01]). Patient survival (PS) among HIV-infected recipients was 83.5% at 5 years and 51.6% at 10 years and was significantly lower than PS among HIV-negative controls (HR, 1.34; 95% CI, 1.08 to 1.68; P<0.01). However, PS was similar for HIV monoinfected recipients and HIV-negative/HCV-negative controls at both times. HIV/HCV coinfected recipients had worse PS compared with HIV-negative/HCV-infected controls (5-year: 67.0% versus 78.6%, P=0.007; 10-year: 29.3% versus 56.23%, P=0.002 [HR, 1.57; 95% CI, 1.11 to 2.22; P=0.01]). In conclusion, HIV-negative and HIV monoinfected kidney transplant recipients had similar GS and PS, whereas HIV/HCV coinfected recipients had worse outcomes. Although encouraging, these results suggest caution in transplanting coinfected patients.

Risk of injury for occupants of motor vehicle collisions from unbelted occupants

Objective: Unbelted occupants may increase the risk of injury for other occupants in a motor vehicle collision (MVC). This study evaluated the association between occupant restraint use and the risk of injury (including death) to other vehicle occupants. Design: A population based cohort study. Setting: United States. Subjects: MVC occupants (n = 152 191 unweighted, n = 18 426 684 weighted) seated between a belted or unbelted occupant and the line of the principal direction of force in frontal, lateral, and rear MVCs were sampled from the 1991–2002 National Automotive Sampling System General Estimates System. Offset MVCs were not included in the study. Main outcome measure: Risk ratios and 95% confidence intervals for injury (including death) for occupants seated contiguous to unbelted occupants compared to occupants seated contiguous to belted occupants. Risk ratios were adjusted for at risk occupant’s sex, age, seating position, vehicle type, collision type, travel speed, crash severity, and at risk occupants’ own seat belt use. Results: Exposure to unbelted occupants was associated with a 40% increased risk of any injury. Belted at risk occupants were at a 90% increased risk of injury but unbelted occupants were not at increased risk. Risks were similar for non-incapacitating and capacitating injuries. There was a 4.8-fold increased risk of death for exposed belted occupants but no increased risk of death for unbelted occupants. Conclusions: Belted occupants are at an increased risk of injury and death in the event of a MVC from unbelted occupants.

Motor vehicle crash-related mortality is associated with prehospital and hospital-based resource availability.

BACKGROUND To date, attempts to assess the relationship between motor vehicle collision (MVC)-related mortality and medical resources availability have largely been unsuccessful. METHODS Information regarding sociodemographic characteristics, prehospital resources, and hospital-based resources for each county (n = 67) in the state of Alabama was obtained. MVC-related mortality rates (deaths per 1,000 collisions) by county were calculated and compared according to prehospital and hospital-based resource availability within each county after correcting for sociodemographic factors. RESULTS Counties with 24-hour availability of a general surgeon, orthopedic surgeon, neurosurgeon, computed tomographic scanner, and operating room were shown to have decreased MVC-related mortality (relative risk [RR], 0.88). The same was true for those counties with hospitals classified as Level I-II (RR, 0.71) and Level III-IV (RR, 0.83) trauma centers compared with counties with no trauma centers. CONCLUSION Appropriate, readily available hospital-based resources are associated with lower MVC-related mortality rates. This information may be useful in trauma system planning and development.

Comparison of Posthospitalization Function and Community Mobility in Hospital Mobility Program and Usual Care Patients: A Randomized Clinical Trial

IMPORTANCE Low mobility is common during hospitalization and associated with loss or declines in ability to perform activities of daily living (ADL) and limitations in community mobility. OBJECTIVE To examine the effect of an in-hospital mobility program (MP) on posthospitalization function and community mobility. DESIGN, SETTING, AND PARTICIPANTS This single-blind randomized clinical trial used masked assessors to compare a MP with usual care (UC). Patients admitted to the medical wards of the Birmingham Veterans Affairs Medical Center from January 12, 2010, through June 29, 2011, were followed up throughout hospitalization with 1-month posthospitalization telephone follow-up. One hundred hospitalized patients 65 years or older were randomly assigned to the MP or UC groups. Patients were cognitively intact and able to walk 2 weeks before hospitalization. Data analysis was performed from November 21, 2012, to March 14, 2016. INTERVENTIONS Patients in the MP group were assisted with ambulation up to twice daily, and a behavioral strategy was used to encourage mobility. Patients in the UC group received twice-daily visits. MAIN OUTCOMES AND MEASURES Changes in self-reported ADL and community mobility were assessed using the Katz ADL scale and the University of Alabama at Birmingham Study of Aging Life-Space Assessment (LSA), respectively. The LSA measures community mobility based on the distance through which a person reports moving during the preceding 4 weeks. RESULTS Of 100 patients, 8 did not complete the study (6 in the MP group and 2 in the UC group). Patients (mean age, 73.9 years; 97 male [97.0%]; and 19 black [19.0%]) had a median length of stay of 3 days. No significant differences were found between groups at baseline. For all periods, groups were similar in ability to perform ADL; however, at 1-month after hospitalization, the LSA score was significantly higher in the MP (LSA score, 52.5) compared with the UC group (LSA score, 41.6) (P = .02). For the MP group, the 1-month posthospitalization LSA score was similar to the LSA score measured at admission. For the UC group, the LSA score decreased by approximately 10 points. CONCLUSIONS AND RELEVANCE A simple MP intervention had no effect on ADL function. However, the MP intervention enabled patients to maintain their prehospitalization community mobility, whereas those in the UC group experienced clinically significant declines. Lower life-space mobility is associated with increased risk of death, nursing home admission, and functional decline, suggesting that declines such as those observed in the UC group would be of great clinical importance. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00715962.

Microvascular response to red blood cell transfusion in trauma patients.

ABSTRACT Trauma patients are often transfused allogeneic red blood cells (RBCs) in an effort to augment tissue oxygen delivery. However, the effect of RBC transfusion on microvascular perfusion in this patient population is not well understood. To this end, we investigated the effect of RBC transfusion on sublingual microvascular perfusion in trauma patients. Sublingual microcirculation was imaged at bedside with a sidestream dark-field illumination microscope before and after transfusion of one RBC unit in hemodynamically stable, anemic trauma patients. The perfused proportion of capillaries (PPC) before and after transfusion was determined, and the percent change in capillary perfusion following transfusion (&Dgr;PPC) calculated. Sublingual microcirculation was observed in 30 patients. Mean age was 47 (SD, 21) years, mean Injury Severity Score was 29 (SD, 16), and mean pretransfusion hemoglobin was 7.5 (SD, 0.9) g/dL. No patients had a mean arterial pressure of less than 65 mmHg (mean, 89 [SD, 17] mmHg) or lactate of greater than 2.5 mmol/L (mean, 1.1 [SD, 0.3] mmol/L). Following transfusion, &Dgr;PPC ranged from +68% to −36% and was found to inversely correlate significantly with pretransfusion PPC (Spearman r = −0.63, P = 0.0002). Pretransfusion PPC may be selectively deranged in otherwise stable trauma patients. Patients with relatively altered baseline PPC tend to demonstrate improvement in perfusion following transfusion, whereas those with relatively normal perfusion at baseline tend to demonstrate either no change or, in fact, a decline in PPC. Bedside sublingual imaging may have the potential to detect subtle perfusion defects and ultimately inform clinical decision making with respect to transfusion.

The deleterious effect of red blood cell storage on microvascular response to transfusion.

BACKGROUND The transfusion of relatively older red blood cells (RBCs) has been associated with both morbidity and mortality in trauma patients in observational studies. Although the mechanisms responsible for this phenomenon remain unclear, alterations in the microcirculation as a result of the transfusion of relatively older blood may be a causative factor. To assess this hypothesis, we evaluated microvascular perfusion in trauma patients during RBC transfusion. METHODS Anemic but otherwise stable trauma intensive care unit patients with orders for transfusion were identified. Thenar muscle tissue oxygen saturation (StO2) was measured continuously by near-infrared spectroscopy during the course of transfusion of one RBC unit. Sublingual microcirculation was observed by sidestream dark-field illumination microscopy before and after transfusion of one RBC unit. Thenar muscle StO2 was recorded during the course of transfusion. Pretransfusion and posttransfusion perfused capillary vascular density (PCD) was determined by semiquantitative image analysis. Changes in StO2 and PCD relative to age of RBC unit were evaluated using mixed models that adjusted for baseline StO2 and Spearman correlation, respectively. RESULTS Overall, 93 patients were recruited for study participation, 69% were male, and average Injury Severity Score (ISS) was 26.4. The average pretransfusion hemoglobin was 7.5 mg/dL, and the average age of RBC unit transfused was 29.4 days. The average peritransfusion StO2 was negatively associated with increasing RBC age (slope, −0.11; p = 0.0014). Change in PCD from pretransfusion to posttransfusion period was found to correlate negatively with RBC storage age (Spearman correlation, −0.27; p = 0.037). CONCLUSION The transfusion of relatively older RBC units was associated with a decline in both StO2 and PCD. Collectively, these observations demonstrate that transfusions of older RBC units are associated with the inhibition of regional microvascular perfusion. In patients requiring multiple units of RBCs, alteration of the microcirculation by relatively older units could potentially contribute to adverse outcomes. LEVEL OF EVIDENCE Prognostic study, level III.

Long-term Outcomes After Liver Transplantation Among Human Immunodeficiency Virus-Infected Recipients.

Background Early outcomes after human immunodeficiency virus (HIV) + liver transplantation (LT) are encouraging, but data are lacking regarding long-term outcomes and comparisons with matched HIV− patients. Methods We examined outcomes among 180 HIV+ LT, and compared outcomes to matched HIV− counterfactuals (Scientific Registry of Transplant Recipients 2002-2011). Iterative expanding radius matching (1:10) on recipient age, race, body mass index, hepatitis C virus (HCV), model for end-stage liver disease score, and acute rejection; and donor age and race, cold ischemia time, and year of transplant. Patient survival and graft survival were estimated using Kaplan-Meier methodology and compared using log-rank and Cox proportional hazards. Subgroup analyses were performed by transplant era (early: 2002-2007 vs modern: 2008-2011) and HCV infection status. Results Compared to matched HIV− controls, HIV+ LT recipients had a 1.68-fold increased risk for death (adjusted hazard ratio [aHR], 1.68, 95% confidence interval [95% CI], 1.28-2.20; P < 0.001), and a 1.70-fold increased risk for graft loss (aHR, 1.70; 95% CI, 1.31-2.20; P < 0.001). These differences persisted independent of HCV infection status. However, in the modern transplant era risk for death (aHR, 1.11; 95% CI, 0.52-2.35; P = 0.79) and graft loss (aHR, 0.89; 95% CI, 0.42-1.88; P = 0.77) were similar between monoinfected and uninfected LT recipients. In contrast, independent of transplant era, coinfected LT recipients had increased risk for death (aHR, 2.24; 95% CI, 1.43-3.53; P < 0.001) and graft loss (aHR, 2.07; 95% CI, 1.33-3.22; P = 0.001) compared to HCV+ alone LT recipients. Conclusions These results suggest that outcomes among monoinfected HIV+ LT recipients have improved over time. However, outcomes among HIV+ LT recipients coinfected with HCV remain concerning and motivate future survival benefit studies.