Cristobal Barrios

Standard prophylactic enoxaparin dosing leads to inadequate anti-Xa levels and increased deep venous thrombosis rates in critically Ill trauma and surgical patients

BACKGROUND Deep venous thromboses (DVT) continue to cause significant morbidity in critically ill patients. Standard prophylaxis for high risk patients includes twice-daily dosing with 30 mg enoxaparin. Despite prophylaxis, DVT rates still exceed 10% to 15%. Anti-Xa levels are used to measure the activity of enoxaparin and 12-hour trough levels <or=0.1 IU/mL have been associated with higher rates of DVT in orthopedic patients. We hypothesized that low Anti-Xa levels would be found in critically ill trauma and surgical patients and that low levels would be associated with higher rates of DVT. METHODS All patients on the surgical intensive care unit (ICU) service were prospectively followed. In the absence of contraindications, patients were given prophylactic enoxaparin and anti-Xa levels were drawn after the third dose. Trough levels <or=0.1 IU/mL were considered low. Screening duplex exams were obtained within 48 hours of admission and then weekly. Patients were excluded if they did not receive a duplex, if they had a prior DVT, or if they lacked correctly timed anti-Xa levels. DVT rates and demographic data were compared between patients with low and normal anti-Xa levels. RESULTS Data were complete for 54 patients. Eighty-five percent suffered trauma (Injury Severity Score of 25 +/- 12) and 74% were male. Overall, 27 patients (50%) had low anti-Xa levels. Patients with low anti-Xa levels had significantly more DVTs than those with normal levels (37% vs. 11%, p = 0.026), despite similar age, body mass index, Injury Severity Score, creatinine clearance, high risk injuries, and ICU/ventilator days. CONCLUSION Standard dosing of enoxaparin leads to low anti-Xa levels in half of surgical ICU patients. Low levels are associated with a significant increase in the risk of DVT. These data support future studies using adjusted-dose enoxaparin.

Acute care surgery: a new training and practice model in the United States.

The specialty of trauma is at a crossroads. Choosing a career in trauma is associated with concerns related to lifestyle issues and maintenance of adequate operative experience. Trauma and critical care surgeons in the U.S. have reexamined their role based on these concerns and the realization that surgeon resources for the injured patient are in jeopardy. After much work over the past five years, a model of “Acute Care Surgery” has emerged and a training curriculum has been proposed. This article reviews the evolution of a new specialty and identifies some of the challenges and opportunities associated with the implementation of this model.

Which central venous catheters have the highest rate of catheter-associated deep venous thrombosis: a prospective analysis of 2,128 catheter days in the surgical intensive care unit.

BACKGROUND Catheter-associated deep venous thromboses (CADVTs) are a common occurrence in the surgical intensive care unit (SICU), necessitating central venous catheter (CVC) removal and replacement. Previous studies evaluating risk factors for CADVT in SICU patients are limited, and most lack a true denominator of all CVC days. We sought to determine the true incidence of and risk factors for CADVT based on patient characteristics as well as CVC site, type, and duration of insertion. METHODS The following data from all SICU patients in two urban Level I trauma centers were prospectively collected from 2009 to 2012: demographics, risk factors for DVT, CVC site/type/duration, and duplex results. Sites included the subclavian (SC), internal jugular (IJ), arm (for peripherally inserted central catheter [PICC] lines), and femoral. Types included multilumen (ML), introducer/hemodialysis (I/HD), and PICC. High-risk patients received weekly screening duplex examinations and a CADVT was defined as a DVT being detected on duplex with a CVC in place or within 7 days of removal. Rates of CADVT were normalized per 1,000 CVC days, and independent predictors of CADVT were determined using logistic regression. RESULTS Data were complete for 184 patients, 354 CVCs, and 2,128 CVC days. Fifty-nine CADVTs were diagnosed in 28% of patients. Rates of CADVT were 9 per 1,000 catheter days for SC, 61 for IJ (p < 0.01 vs. SC), 27 for arm (p < 0.01), 36 for femoral (p < 0.01), 22 for ML, 57 for I/HD (p < 0.01 vs. ML), and 27 for PICC (p = 0.24). After adjusting for patient risk factors, predictors of CADVT included the IJ and arm sites (odds ratio, 6.0 and 3.0 compared with SC) and the I/HD type (odds ratio, 2.6 compared with ML, all p < 0.05). CONCLUSION The IJ and arm sites and I/HD type are associated with increased CADVT. These data may be used to determine the optimal site and type of CVC for insertion. LEVEL OF EVIDENCE Prognostic/epidemiologic study, level III.

Ability of a chest X-ray and an abdominal computed tomography scan to identify traumatic thoracic injury

OBJECTIVE Our objective was to show that a chest X-ray (CXR) and an abdominal computed tomography (CT) scan are sufficient to identify most clinically significant thoracic injuries in trauma patients, rendering the thoracic CT scan useful in only a subset of patients. METHODS A retrospective study identified thoracic injuries in 374 trauma patients evaluated with a CXR, a thoracic CT scan, and an abdominal CT scan. Injuries seen on the initial CXR versus those seen on a CT scan only (occult) were identified and assessed for clinical relevance. RESULTS An abdominal CT scan identified 65% (15/23) of occult pneumothoraces, 100% (25/25) of occult hemothoraces, 64% (18/28) of occult pulmonary contusions, and 58% (18/31) of occult rib fractures. No occult pneumothoraces seen on the thoracic CT scan alone required tube thoracostomy. CONCLUSIONS Our pilot study suggests that a CXR and an abdominal CT scan will identify most occult intrathoracic injuries. Reserving a thoracic CT scan for patients with an abnormal CXR or high-risk mechanism could safely reduce cost and radiation exposure while still diagnosing significant thoracic injuries.

Risk factors for venous thromboembolism in critically ill trauma patients who cannot receive chemical prophylaxis

BACKGROUND Standard venous thromboembolism (VTE) prevention for critically ill trauma patients includes sequential compression devices and chemical prophylaxis. When contraindications to anticoagulation are present, prophylactic inferior vena cava filters (IVCF) may be used to prevent pulmonary emboli (PE) in high-risk patients, but specific indications are lacking. We sought to identify independent predictors of VTE in critically-ill trauma patients who cannot receive chemical prophylaxis in order to identify a subset of patients who may benefit from aggressive screening and/or prophylactic IVCF placement. METHODS All trauma patients in the surgical ICU from 2008 to 2009 were prospectively followed. Patients with an ICU length of stay ≥2 days who had contraindications to prophylactic anticoagulation were included. Screening duplex exams were obtained within 48 h of admission and then weekly. CT-angiography for PE was obtained if clinically indicated. Patients were excluded if they did not receive a duplex or if they had a post-injury VTE prior to ICU admission. Data regarding VTE rates (lower extremity [LE] DVT or PE), demographics, past medical history (PMH), injuries, and surgeries were collected. Univariate and multivariable analyses were performed to identify independent predictors of VTE with a p<0.05. RESULTS 411 trauma patients with a mean age of 48 (SD 22) years and 8 (SD 9) ICU days were included. 72% were male and the mean ISS was 22 (SD 13). 30 (7.3%) patients developed VTE: 28 (6.8%) with LEDVT and 2 (0.5%) with PE. Risk factors for VTE with a p<0.2 on univariate analysis included: PMH of DVT, injury severity score (ISS), extremity fractures (Fx), and a pelvis or LE extremity Fx repair. After logistic regression, only PMH of DVT (OR=22.6) and any extremity Fx (OR=2.4) remained as independent predictors. CONCLUSION VTE occur in 7% of critically injured trauma patients who cannot receive chemical prophylaxis. Aggressive screening and/or prophylactic IVCF placement may be considered in patients with a PMH of DVT or extremity fractures when anticoagulation is prohibited.

Predictors of Hazardous Drinking Behavior in 1,340 Adult Trauma Patients: A Computerized Alcohol Screening and Intervention Study

BACKGROUND Alcohol screening and brief intervention (SBI) is used to decrease alcohol consumption, health care costs, and injury recidivism in trauma patients. Despite SBI being mandated for trauma centers, various concerns have led many centers to conduct SBI only on patients with a detectable blood alcohol concentration (BAC). We sought to determine the predictive nature of BAC on hazardous drinking behavior. STUDY DESIGN Adult trauma patients were included if they received an SBI before discharge. SBI was administered using a computerized alcohol screening and intervention (CASI) system with the Alcohol Use Disorder Identification Test (AUDIT). Data regarding demographics, injuries, and BAC were prospectively collected. Multivariate analyses were performed to identify independent predictors of hazardous drinking behavior. RESULTS Data were complete for 1,340 patients, with a mean age of 43 years (SD 20 years). Sixty-eight percent were male, 33% had detectable BAC, and 19% had hazardous drinking behavior. Multivariate analysis identified age (odds ratio [OR] 0.97 per year), male sex (OR 3.1), BAC (OR 1.009 per mg/dL), detectable BAC (OR 3.9), and legal intoxication (OR 7.8) as independent predictors of hazardous drinking behavior. Asian/Pacific Islander ethnicity was a significant negative predictor (OR 0.53) compared with white. Thirty-eight percent of patients with hazardous drinking behavior had no detectable BAC. CONCLUSIONS Younger age, male sex, and higher BAC are early predictors of hazardous drinking behavior in adult trauma patients. Asian/Pacific Islander patients are half as likely to report hazardous drinking behavior compared with white patients. More than one-third of patients with hazardous drinking behavior do not have detectable BAC on admission and are not receiving interventions in centers that screen solely based on BAC.

The natural history of upper extremity deep venous thromboses in critically ill surgical and trauma patients: what is the role of anticoagulation?

BACKGROUND The natural history and optimal treatment of upper extremity (UE) deep venous thromboses (DVTs) remains uncertain as does the clinical significance of catheter-associated (CA) UE DVTs. We sought to analyze predictors of UE DVT resolution and hypothesized that anticoagulation will be associated with quicker UE DVT clot resolution and that CA UE DVTs whose catheters are removed will resolve more often than non-CA UE DVTs. METHODS All patients on the surgical intensive care unit service were prospectively followed from January 2008 to May 2010. A standardized DVT prevention protocol was used and screening bilateral UE and lower extremity duplex examinations were obtained within 48 hours of admission and then weekly. Computed tomography angiography for pulmonary embolism was obtained if clinically indicated. Patients with UE DVT were treated according to attending discretion. Data regarding patient demographics and UE DVT characteristics were recorded: DVT location, catheter association, occlusive status, treatment, and resolution. The primary outcome measure was UE DVT resolution before hospital discharge. Interval decrease in size on the subsequent duplex after UE DVT detection was also noted. UE DVTs without a follow-up duplex were excluded from the final analysis. Univariate and multivariate analyses were used to identify independent predictors of UE DVT resolution. RESULTS There were 201 UE DVTs in 129 patients; 123 DVTs had a follow-up duplex and were included. Fifty-four percent of UEDVTs improved on the next duplex, 60% resolved before discharge, and 2% embolized. The internal jugular was the most common site (52%) and 72% were nonocclusive. Sixty-four percent were CAUEDVTs and line removal was associated with more frequent improvement on the next duplex (55% vs. 17%, p = 0.047, mid-P exact). Sixty-eight percent of UEDVTs were treated with some form of anticoagulation, but this was not associated with improved UE DVT resolution (61% vs. 60%). Independent predictors of clot resolution were location in the arm (odds ratio = 4.1 compared with the internal jugular, p = 0.031) and time from clot detection until final duplex (odds ratio =1.052 per day, p = 0.032). CONCLUSION A majority of UE DVTs are CA, more than half resolve before discharge, and 2% embolize. Anticoagulation does not appear to affect outcomes, but line removal does result in a quicker decrease in clot size.

Assessment of Readiness to Change and Relationship to AUDIT Score in a Trauma Population Utilizing Computerized Alcohol Screening and Brief Intervention

Trauma patient readiness-to-change score and its relationship to the Alcohol Use Disorder Identification Test (AUDIT) score were assessed in addition to the feasibility of computerized alcohol screening and brief intervention (CASI). A bilingual computerized tablet for trauma patients was utilized and the data were analyzed using Stata. Twenty-five percent of 1145 trauma patients drank more than recommended and 4% were dependent. As many Spanish-speaking as English-speaking males did not drink, but a higher percentage of Spanish-speaking males drank more than recommended and were dependent. Half of patients who drank more than recommended rated themselves 8 or higher on a 10-point readiness-to-change scale. CASI also provided personalized feedback. A high percentage of trauma patients (92%) found CASI easy and a comfort in use (87%). Bilingual computerized technology for trauma patients is feasible, acceptable, and an innovative approach to alcohol screening, brief intervention, and referral to treatment in a tertiary care university.

A comparison of thoracic CT and abdominal CT for the identification of thoracic blunt trauma

BACKGROUND In light of current trends to limit radiation exposure and costs, as well as increased traffic safety, computed tomography (CT) may have decreasing value for evaluating patients with blunt trauma. The authors examined the utility of chest x-ray and abdominal CT for identifying clinically significant thoracic blunt trauma. METHODS In this prospective study, findings on thoracic CT, abdominal CT, and chest x-ray from trauma patients were compared to assess injury prevalence and relevance to treatment outcomes. RESULTS Four hundred forty-four patients were identified, of whom 76% had no findings. Occult findings had significantly lower Injury Severity Scores. All clinically relevant pneumothoraces and most other injuries could be identified without thoracic CT. Two of 3 aortic abnormalities were suspected from chest x-ray. CONCLUSIONS Clinically significant injuries can be identified with abdominal CT and chest x-ray, safely allowing reductions in radiation exposure, hospital stays, and costs by limiting the use of thoracic CT.

A retrospective analysis of ethnic and gender differences in alcohol consumption among emergency department patients: A cross-sectional study

BackgroundPrevious studies of alcohol use have recognized several trends in consumption patterns among gender and age yet few have examined ethnic differences. This study examines the intra- and inter-ethnic differences in alcohol consumption among a population of patients seen in the emergency department.MethodsThis is a cross-sectional study conducted in the emergency department in a large urban setting. Information on drinking behavior and ethnicity was collected using the Computerized Alcohol Screening and Brief Intervention (CASI) tool. We explored differences in drinking patterns using a multivariate multinomial logistic regression model.ResultsWe analyzed the drinking habits of 2,444 patients surveyed between November 2012 and May 2014. The results indicate that when compared to non-Hispanic whites, Asians have the lowest odds of drinking within normal limits or excessively, followed by other Latinos, and Mexicans. Age and gender consistently showed statistically significant associations with alcohol-use. The odds of drinking within normal limits or excessively are inversely associated with age and were lower among females. The predicted probabilities show a marked gender-specific difference in alcohol use both between and within ethnic/racial groups. They also highlight an age-related convergence in alcohol use between men and women within ethnic groups.DiscussionThe results of this study show intra-racial/ethnic variability associated with sex and education. The highlighted differences within and between ethnic groups reinforce the need to use refined categories when examining alcohol use among minorities.ConclusionThe results of this study confirm some alcohol consumption trends among ethnic minorities observed in literature. It provides empirical evidence of the marked gender differences and highlights an age-related convergence for gender-specific alcohol use. Health-care personnel should be aware of these differences when screening and counseling.