Ben L. Zarzaur

Temporary abdominal closure techniques: a prospective randomized trial comparing polyglactin 910 mesh and vacuum-assisted closure.

OBJECTIVE The options for abdominal coverage after damage control laparotomy or abdominal compartment syndrome vary by institution, surgeon preference, and type of patient. Some advocate polyglactin mesh (MESH), while others favor vacuum-assisted closure (VAC). We performed a single institution prospective randomized trial comparing morbidity and mortality differences between MESH and VAC. METHODS Patients expected to survive and requiring open abdomen management were prospectively randomized to either MESH or VAC. After randomization, an enteral feeding tube was inserted and the closure device placed. VAC patients returned to the operating room every 3 days for a total of three changes at which time polyglactin mesh was placed if closure was not possible. The MESH group had twice daily assessments for the possibility of bedside mesh cinching and closure. Both groups underwent split thickness skin grafting when granulation tissue was evident, if delayed primary closure was not possible. RESULTS Fifty-one patients were randomized. Both cohorts were matched for Injury Severity Scale score, gender, blunt/penetrating/abdominal compartment syndrome and age. Three patients died within 7 days and were excluded from closure rate calculation. There were no differences between delayed primary fascial closure rates in the VAC (31%) or MESH (26%) groups. The fistula rate in the VAC group was 21% but not statistically different from the 5% rate for MESH. Intraabdominal rates were not statistically different. All VAC fistulas were related to feeding tubes and suture line areas; the MESH fistula followed a retroperitoneal colon leak remote from the mesh. CONCLUSIONS MESH and VAC are both useful methods for abdominal coverage, and are equally likely to produce delayed primary closure. The fistula rate for VAC is most likely due to continued bowel manipulation with VAC changes with a feeding tube in place-enteral feeds should be administered via nasojejunal tube. Neither method precludes secondary abdominal wall reconstruction.

Blood transfusion is an independent predictor of increased mortality in nonoperatively managed blunt hepatic and splenic injuries.

BACKGROUND Management strategies for blunt solid viscus injuries often include blood transfusion. However, transfusion has previously been identified as an independent predictor of mortality in unselected trauma admissions. We hypothesized that transfusion would adversely affect mortality and outcome in patients presenting with blunt hepatic and splenic injuries after controlling for injury severity and degree of shock. METHODS We retrospectively reviewed records from all adults with blunt hepatic and/or splenic injuries admitted to a Level I trauma center over a 4-year period. Demographics, physiologic variables, injury severity, and amount of blood transfused were analyzed. Univariate and multivariate analysis with logistic and linear regression were used to identify predictors of mortality and outcome. RESULTS One hundred forty-three (45%) of 316 patients presenting with blunt hepatic and/or splenic injuries received blood transfusion within the first 24 hours. Two hundred thirty patients (72.8%) were selected for nonoperative management, of whom 75 (33%) required transfusion in the first 24 hours. Transfusion was an independent predictor of mortality in all patients (odds ratio [OR], 4.75; 95% confidence interval [CI], 1.37-16.4; p = 0.014) and in those managed nonoperatively (OR, 8.45; 95% CI, 1.95-36.53; p = 0.0043) after controlling for indices of shock and injury severity. The risk of death increased with each unit of packed red blood cells transfused (OR per unit, 1.16; 95% CI, 1.10-1.24; p < 0.0001). Blood transfusion was also an independent predictor of increased hospital length of stay (coefficient, 5.45; 95% CI, 1.64-9.25; p = 0.005). CONCLUSION Blood transfusion is a strong independent predictor of mortality and hospital length of stay in patients with blunt liver and spleen injuries after controlling for indices of shock and injury severity. Transfusion-associated mortality risk was highest in the subset of patients managed nonoperatively. Prospective examination of transfusion practices in treatment algorithms of blunt hepatic and splenic injuries is warranted.

Glutamine-Enriched Total Parenteral Nutrition Maintains Intestinal Interleukin-4 and Mucosal Immunoglobulin A Levels

BACKGROUND Total parenteral nutrition (TPN) prevents progressive malnutrition but fails to maintain intestinal gut-associated lymphoid tissue (GALT) or established respiratory antiviral or antibacterial mucosal immunity. Our previous work demonstrated that decreases in intestinal immunoglobulin A (IgA) were associated with decreases in Th2-type IgA-stimulating cytokines, interleukin (IL)-4 and IL-10. Because glutamine supplementation of TPN partially preserves respiratory defenses and normalizes GALT, we investigated the ability of parenteral glutamine to normalize respiratory and intestinal IgA levels and measured Th2 cytokines in intestinal homogenates. METHODS Animals were cannulated and randomly assigned to receive chow (n = 17), TPN (n = 18), or an isonitrogenous, isocaloric TPN solution formulated by removing the appropriate amount of amino acids and replacing them with 2% glutamine (n = 18) for 5 days. Respiratory tract and intestinal washings were obtained for IgA and the intestine homogenized and analyzed for IL-4 and IL-10. RESULTS TPN decreased intestinal and respiratory IgA in association with decreases in intestinal IL-4 and IL-10 compared with chow-fed animals. Glutamine significantly improved respiratory and intestinal IgA levels, significantly improved IL-4 compared with TPN animals, and maintained IL-10 levels midway between chow-fed and TPN animals. CONCLUSIONS Glutamine-enriched TPN preserved both extraintestinal and intestinal IgA levels and had a normalizing effect on Th2-type IgA-stimulating cytokines.

TPN decreases IL-4 and IL-10 mRNA expression in lipopolysaccharide stimulated intestinal lamina propria cells but glutamine supplementation preserves the expression.

Total parenteral nutrition (TPN) decreases intestinal IgA and levels of Th2 cytokines, interleukin (IL)-4, and IL-10 within the supernatants of intestinal homogenates. These cytokines are known to stimulate IgA production in vitro by cells of the gut-associated lymphoid tissue (GALT). Glutamine (GLN) supplementation of TPN normalizes GALT mass and cytokine levels. Because intestinal homogenates contain mucosa which itself is a source of cytokines, it was unclear whether cytokines change within the GALT itself. This study investigates dietary effects on IL-4 and IL-10 cytokine mRNA expression within isolated GALT lamina propria cells after lipopolysaccharide (LPS) stimulation. Prospective randomized experimental trials were used in this study. Fifty-nine mice were randomized to chow, intravenous TPN (IV-TPN), intragastric TPN (IG-TPN), complex enteral diet (CED), or 2% GLN-supplemented TPN (GLN-TPN). In experiment 1, animals were fed chow, IV-TPN, IG-TPN, or CED for 5 days and received intraperitoneal LPS (100 microg/kg BW), and then were sacrificed 1 h later. Intestine was harvested for GALT lamina propria. Total RNA was extracted from lamina propria cells and cytokine mRNA for IL-4, and IL-10 was measured by reverse transcriptase polymerase chain reaction. IgA levels of intestinal washing were also measured with ELISA. In experiment 2, mRNA for IL-4 and IL-10, and intestinal IgA levels were measured in mice fed chow, IV-TPN, or GLN-TPN as in experiment 1. Both IL-4 and IL-10 mRNA expression decreased significantly in IV-TPN mice compared to chow or CED feeding. IG-TPN resulted in IL-10 mRNA expression significantly lower than chow or CED but significantly better than IV-TPN. GLN preserved IL-4 and IL-10 mRNA levels, which correlated with intestinal IgA levels. Route and type of nutrition as well as GLN influence message for the Th2 type IgA-stimulating cytokines, IL-4 and IL-10, within the primary site of GALT IgA production, the lamina propria.

New Vitals After Injury: Shock Index for the Young and Age × Shock Index for the Old

BACKGROUND The traditional view that tachycardia and hypotension accompany hemorrhagic shock following injury has been challenged. This is particularly true at extremes of age. Shock index (SI) may be an alternative indicator of life-threatening bleeding after injury. Because age negatively impacts physiological reserve, we hypothesized that age multiplied by SI (Age x SI) would be a better predictor of 48 h mortality (48 MORT) compared to heart rate (HR), systolic blood pressure (SBP), or SI. METHODS A Level I trauma center registry was used to identify victims of blunt injury, aged 18-84 (YOUNG < or =55 and OLD >55) admitted from 1996-2005. Patients with head and spinal cord injury injuries were excluded. The main outcome was 48 MORT. Areas under the receiver operating characteristic curves (AUC) for each predictor were determined. RESULTS Sixteen thousand seventy-seven patients were identified. Forty-eight MORT was 1.27% (0.93% in YOUNG and 3.17% in OLD; P < 0.0001). Overall, SI (AUC 0.812) and Age x SI (AUC 0.831) were better predictors of 48 MORT compared to HR (AUC 0.716, P < 0.0001) or SBP (AUC 0.753, P = 0.0004) alone. In OLD patients, AGE x SI (AUC 0.828) was a better predictor of 48 MORT compared to HR (AUC 0.659 P < 0.0001), SBP (AUC 0.762 P = 0.003), or SI (AUC 0.787 P = 0.0005). CONCLUSION SI and Age x SI are better predictors of 48 MORT in injured patients than HR or SBP alone. SI and Age x SI should be used to identify patients at risk for early mortality following injury.

Impact of decompressive craniectomy on functional outcome after severe traumatic brain injury.

BACKGROUND The beneficial effect of decompressive craniectomy (DC) in the treatment of traumatic brain injury (TBI) remains controversial. In many centers, it is used as a salvage procedure for uncontrollable intracranial pressure (ICP). It is our contention that DC represents a viable early option for head trauma patients. The purpose of this study was to evaluate the efficacy of DC on functional outcome after severe TBI in the largest single institutional series reported in the literature. METHODS Patients with severe TBI (Abbreviated Injury Score 4-5) treated with DC for the management of increased ICP during 6-year period were identified from the trauma registry. Functional outcome was measured 1 year to 6 years postinjury using the Glasgow Outcome Score Extended (GOSE) via telephone interview and classified as good (GOSE 5-8) or poor (GOSE 1-4, including death). Outcomes were compared using Wilcoxon rank-sum and chi2 tests where appropriate. RESULTS One hundred and seventy-one patients were identified: 137 (80%) men and 34 (20%) women. Overall mortality (all in-hospital) was 32% (head-related = 22%). Of the 117 survivors, follow-up was obtained in all but 6 (95%). Good outcome was achieved in 96 patients (56% overall, 82% of survivors). Those with good outcome were younger (26 years vs. 43 years, p = 0.0028) and experienced a greater change in predecompression to postdecompression ICP (ICP reduced by 23 mm Hg vs. 10 mm Hg, p < 0.0001). Not surprisingly, unchanged ICP (predecompression to postdecompression) was associated with poor outcome (p = 0.0031). There was no difference in immediate predecompression ICP between survivors versus nonsurvivors. However, immediate predecompression Glasgow Coma Score was significantly higher in survivors compared with nonsurvivors (7 vs. 5, p < 0.0001). CONCLUSIONS DC resulted in good functional outcome in >50% of patients with severe TBI. The greatest benefit was observed in younger patients with a demonstrable reduction in ICP after decompression. The prospect of improved functional outcome offered by this procedure in the treatment of severe TBI warrants prospective investigation.

Enteral Nutrition Prevents Remote Organ Injury and Death After a Gut Ischemic Insult

ObjectiveTo determine whether parenteral feeding (IV-TPN) influences the local and systemic response to an intestinal insult. Summary Background DataParenteral feeding increases ICAM-1 expression and attracts neutrophils (PMNs) to the intestine compared with enterally fed animals. Because the gut is a priming bed for PMNs, the authors hypothesized that IV-TPN may affect organ injury after gut ischemia—reperfusion (I/R). MethodsMice were randomized to chow, IV-TPN, intragastric TPN, or complex enteral diet for 5 days’ feeding. In experiment 1, 162 mice underwent 15 or 30 minutes of gut I/R, and death was recorded at 72 hours. In experiment 2, 43 mice underwent 15 minutes of gut ischemia and permeability was measured by 125I-labeled albumin at 3 hours after reperfusion. Lung PMN accumulation was measured by myeloperoxidase assay. In experiment 3, albumin leak was tested in the complex enteral diet group (n = 5) and the intragastric TPN group (n = 5) after 30 minutes of gut ischemia and 1 hour of reperfusion. ResultsIn experiment 1, enteral feeding significantly reduced the death rate compared with IV-TPN after 15 minutes of I/R. After 30 minutes of gut ischemia, the IV-TPN and intragastric TPN groups showed a higher death rate than the chow and enteral diet groups. In experiment 2, IV-TPN significantly increased pulmonary and hepatic 125I albumin leak compared with enteral feeding without increasing pulmonary myeloperoxidase levels. In experiment 3, there were no differences in 125I albumin leak between the complex enteral diet and intragastric TPN groups. ConclusionEnteral feeding reduced the death rate and organ permeability after 15 minutes of ischemia. However, prolonged ischemia (30 minutes) eliminated any benefits of intragastric TPN on survival.

Improved Survival After Hemostatic Resuscitation: Does the Emperor Have No Clothes?

BACKGROUND In light of recent data, controversy surrounds the apparent 30-day survival benefit of patients achieving a fresh frozen plasma (FFP) to packed red blood cell (PRBC) ratio of at least 1:2 in the face of massive transfusions (MT) (≥10 units of PRBC within 24 hours of admission). We hypothesized that initial studies suffer from survival bias because they do not consider early deaths secondary to uncontrolled exsanguinating hemorrhage. To help resolve this controversy, we evaluated the temporal relationship between blood product administration and mortality in civilian trauma patients receiving MT. METHODS Patients requiring MT over a 22-month period were identified from the resuscitation registry of a Level I trauma center. Shock severity at admission and timing of shock-trauma admission, blood product administration, and death were determined. Patients were divided into high- and low-ratio groups (≥1:2 and<1:2 FFP:PRBC, respectively) and compared. Kaplan-Meier analysis and log-rank test was used to examine 24-hour survival. RESULTS One hundred three patients (63% blunt) were identified (66 high-ratio and 37 low-ratio). Those patients who achieved a high-ratio in 24 hours had improved survival. However, severity of shock was less in the high-group (base excess: -8.0 vs. -11.2, p=0.028; lactate: 6.3 vs. 8.4, p=0.03). Seventy-five patients received MT within 6 hours. Of these, 29 received a high-ratio in 6 hours. Again, severity of shock was less in the high-ratio group (base excess: -7.6 vs. -12.7, p=0.008; lactate: 6.7 vs. 9.4, p=0.02). For these patients, 6-hour mortality was less in the high-group (10% vs. 48%, p<0.002). After accounting for early deaths, groups were similar from 6 hours to 24 hours. CONCLUSIONS Improved survival was observed in patients receiving a higher plasma ratio over the first 24 hours. However, temporal analysis of mortality using shorter time periods revealed those who achieve early high-ratio are in less shock and less likely to die early from uncontrolled hemorrhage compared with those who never achieve a high-ratio. Thus, the proposed survival advantage of a high-ratio may be because of selection of those not likely to die in the first place; that is, patients die with a low-ratio not because of a low-ratio.

Long-Term Follow-Up of Abdominal Wall Reconstruction after Planned Ventral Hernia: A 15-Year Experience

BACKGROUND Although damage control strategies and the open abdomen have improved survival, they present their own unique set of challenges in caring for the multiply injured trauma patient. We previously reported the technique of staged abdominal wall closure for the management of the open abdomen. The purpose of this study was to evaluate the efficacy of various techniques of abdominal wall reconstruction (final stage of management) on long-term outcomes after planned ventral hernia, and to better define risk factors for recurrence. STUDY DESIGN Patients undergoing abdominal wall reconstruction over a 15-year period were identified and stratified by gender, age, severity of shock, injury severity, and method of repair: secondary fascial closure +/- prosthetic, standard components separation (SCS) +/- prosthetic and modified components separation (MCS) +/- prosthetic. Long-term outcomes (recurrence) were determined using hospital records, telephone interview, and physical examination. Multivariable logistic regression analysis was performed to determine independent predictors of recurrence. RESULTS One hundred fifty-two patients were identified. Fourteen (9%) patients underwent secondary fascial closure +/- prosthetic, 47 (31%) underwent SCS +/- prosthetic, and 91 (60%) underwent MCS +/- prosthetic. Long-term follow-up (up to 14.6 years, mean 5.3 years) was obtained in 114 (75%) patients. Sixteen patients (14%) had a recurrence. Prosthetic use increased recurrence 4-fold. There were 2 known recurrences (5%) in patients with MCS without prosthetic. Logistic regression identified both female gender and body mass index as independent predictors of recurrence. CONCLUSIONS The MCS technique is the procedure of choice for repair of giant abdominal wall defects. This approach can avoid the need for prosthetics. In fact, MCS without prosthetic resulted in an acceptably low hernia recurrence rate (5%).

Blunt Cerebrovascular Injury Screening With 32-Channel Multidetector Computed Tomography: More Slices Still Don't Cut It

Objective:We sought to determine the diagnostic accuracy of computed tomographic angiography (CTA) using 32-channel multidetector computed tomography for blunt cerebrovascular injuries (BCVIs). Background:Unrecognized BCVI is a cause of stroke in young trauma patients. Digital subtraction angiography (DSA), the reference standard, is invasive, expensive, and time-consuming. Computed tomographic angiography has been rapidly adopted by many institutions because of its availability, less resource intensive, and noninvasive nature. However, conflicting results comparing CTA and DSA have been reported. Studies with 16-channel CTA report a wide range of sensitivities for BCVI diagnosis. Methods:From January 2007 through May 2009, patients with risk factors for BCVI underwent both CTA and DSA. All CTAs were performed using a 32-channel multidetector CT scanner. Using DSA as the reference standard, the diagnostic accuracy of CTA for determination of BCVI was calculated. Results:There were 684 patients who met the inclusion criteria. Ninety patients (13%) had 109 injuries identified; 52 carotid and 57 vertebral injuries were diagnosed. CTA failed to detect 53 confirmed BCVI, yielding a sensitivity of 51%. Conclusion:Given the devastation of stroke, and high mortality from missed injuries, this study demonstrates that even with more advanced technology (32 vs 16 channel), CTA is inadequate for BCVI screening. Digital subtraction angiography remains the gold standard for the diagnosis of BCVI.