Louis J. Magnotti

Gut-derived mesenteric lymph but not portal blood increases endothelial cell permeability and promotes lung injury after hemorrhagic shock.

OBJECTIVE To determine whether gut-derived factors leading to organ injury and increased endothelial cell permeability would be present in the mesenteric lymph at higher levels than in the portal blood of rats subjected to hemorrhagic shock. This hypothesis was tested by examining the effect of portal blood plasma and mesenteric lymph on endothelial cell monolayers and the interruption of mesenteric lymph flow on shock-induced lung injury. SUMMARY BACKGROUND DATA The absence of detectable bacteremia or endotoxemia in the portal blood of trauma victims casts doubt on the role of the gut in the generation of multiple organ failure. Nevertheless, previous experimental work has clearly documented the connection between shock and gut injury as well as the concept of gut-induced sepsis and distant organ failure. One explanation for this apparent paradox would be that gut-derived inflammatory factors are reaching the lung and systemic circulation via the gut lymphatics rather than the portal circulation. METHODS Human umbilical vein endothelial cell monolayers, grown in two-compartment systems, were exposed to media, sham-shock, or postshock portal blood plasma or lymph, and permeability to rhodamine (10K) was measured. Sprague-Dawley rats were subjected to 90 minutes of sham or actual shock and shock plus lymphatic division (before and after shock). Lung permeability, pulmonary myeloperoxidase levels, alveolar apoptosis, and bronchoalveolar fluid protein content were used to quantitate lung injury. RESULTS Postshock lymph increased endothelial cell monolayer permeability but not postshock plasma, sham-shock lymph/plasma, or medium. Lymphatic division before hemorrhagic shock prevented shock-induced increases in lung permeability to Evans blue dye and alveolar apoptosis and reduced pulmonary MPO levels. In contrast, division of the mesenteric lymphatics at the end of the shock period but before reperfusion ameliorated but failed to prevent increased lung permeability, alveolar apoptosis, and MPO accumulation. CONCLUSIONS Gut barrier failure after hemorrhagic shock may be involved in the pathogenesis of shock-induced distant organ injury via gut-derived factors carried in the mesenteric lymph rather than the portal circulation.

Angiographic embolization for liver injuries: low mortality, high morbidity.

OBJECTIVE Angiographic embolization (AE) is a safe and effective method for controlling hemorrhage in both blunt and penetrating liver injuries. Improved survival after hepatic injuries has been documented using a multimodality approach; however, patients still have significant long-term morbidity. This study examines further the role of AE in both blunt and penetrating liver injuries and the outcomes of its use. METHODS The medical records of 37 consecutive patients admitted from 1995 to 2002 to a Level I trauma center who underwent hepatic angiography with the intent to embolize were reviewed. Demographic and clinical information including Injury Severity Score, length of stay, mortality, intra-abdominal complications, admission physiologic variables, and the number and type of abdominal operations performed were collected. RESULTS Thirty-seven patients underwent hepatic angiography and 26 patients had hepatic embolization performed. Eleven patients underwent early-AE, immediately after computed tomographic scanning, and 15 underwent late-AE, after liver-related operations or later in their hospital course. There was a 27% mortality rate overall. There were 11 liver-related complications in the 26 embolizations. Excluding the early deaths, the associated morbidity was 58%, which included hepatic necrosis, hepatic abscesses, and bile leaks. CONCLUSION There is increasing adjunctive use of AE in patients managed both operatively and nonoperatively. Intra-abdominal complications are common in these salvaged patients with severe liver injuries. Those patients that underwent early-AE received significantly fewer blood transfusions and more commonly had sterile hepatic collections. Only 26% of patients required liver-related surgery after AE. Therefore, the integration of AE as an adjunctive modality for patients with high-grade liver injuries is a safe and effective therapeutic option.

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.

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.

Mesenteric lymph duct ligation provides long term protection against hemorrhagic shock-induced lung injury.

Recently we have shown that ligation of the main mesenteric lymph (MLN) duct prior to an episode of hemorrhagic shock (HS) prevents shock-induced lung injury. Yet, ligation or diversion of intestinal lymph immediately prior to injury is not clinically feasible. Diversion of intestinally derived lymph after injury to protect against secondary insults is possible, but it is not known how long the protective effects of lymph ligation would last. Thus, we tested whether ligation of the MLN duct seven days prior to HS would still be protective. Male Sprague-Dawley rats were subjected to laparotomy with or without MLN duct ligation. Seven days later, half of the sham and actual MLN duct ligated animals randomly were selected to undergo HS (30 mmHG for 90 min). The other half of the animals was subjected to sham shock. Lung permeability, pulmonary myeloperoxidase (MPO) activity, and bronchoalveolar fluid (BALF) protein content were used to determine lung injury. Lymphatic division 7 days prior to HS continued to prevent shock induced lung injury as assessed by a lower Evans Blue dye concentration, BALF protein and MPO activity. In addition, there was no evidence of Patent Blue dye in the previously ligated MLN duct. Since ligation of the main mesenteric lymphatic duct continues to protect against shock-induced lung injury 1 week after duct ligation, it is feasible that lymphatic ligation performed after an injury remains protective against certain secondary insults for at least 1 week.

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.

Improving Outcomes Following Penetrating Colon Wounds: Application Of A Clinical Pathway

IntroductionDuring World War II, failure to treat penetrating colon injuries with diversion could result in court martial. Based on this wartime experience, colostomy for civilian colon wounds became the standard of care for the next 4 decades. Previous work from our institution demonstrated that primary repair was the optimal management for nondestructive colon wounds. Optimal management of destructive wounds requiring resection remains controversial. To address this issue, we performed a study that demonstrated risk factors (pre or intraoperative transfusion requirement of more than 6 units of packed red blood cells, significant comorbid diseases) that were associated with a suture line failure rate of 14%, and of whom 33% died. Based on these outcomes, a clinical pathway for management of destructive colon wounds was developed. The results of the implementation of this pathway are the focus of this report. MethodsPatients with penetrating colon injury were identified from the registry of a level I trauma center over a 5-year period. Records were reviewed for demographics, injury characteristics, and outcome. Patients with nondestructive injuries underwent primary repair. Patients with destructive wounds but no comorbidities or large transfusion requirement underwent resection and anastomosis, while patients with destructive wounds and significant medical illness or transfusion requirements of more than 6 units/blood received end colostomy. The current patients (CP) were compared to the previous study (PS) to determine the impact of the clinical pathway. Outcomes examined included colon related mortality and morbidity (suture line leak and abscess). ResultsOver a 5.5-year period, 231 patients had penetrating colon wounds. 209 survived more 24 hours and comprise the study population. Primary repair was performed on 153 (73%) patients, and 56 patients had destructive injuries (27%). Of these, 40 (71%) had resection and anastomosis and 16 (29%) had diversion. More destructive injuries were managed in the CP group (27% vs. 19%). Abscess rate was lower in the CP group (27% vs. 37%), as was suture line leak rate (7% vs. 14%). Colon related mortality in the CP group was 5% as compared with 12% in the PS group. ConclusionsThe clinical pathway for destructive colon wound management has improved outcomes as measured by anastomotic leak rates and colon related mortality. The data demonstrated the need for colostomy in the face of shock and comorbidities. Institution of this pathway results in colostomy for only 7% of all colon wounds.

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.

An evidence-based approach to patient selection for emergency department thoracotomy: A practice management guideline from the Eastern Association for the Surgery of Trauma

BACKGROUND Within the GRADE (Grading of Recommendations Assessment, Development and Evaluation) framework, we performed a systematic review and developed evidence-based recommendations to answer the following PICO (Population, Intervention, Comparator, Outcomes) question: should patients who present pulseless after critical injuries (with and without signs of life after penetrating thoracic, extrathoracic, or blunt injuries) undergo emergency department thoracotomy (EDT) (vs. resuscitation without EDT) to improve survival and neurologically intact survival? METHODS All patients who underwent EDT were included while those involving either prehospital resuscitative thoracotomy or operating room thoracotomy were excluded. Quantitative synthesis via meta-analysis was not possible because no comparison or control group (i.e., survival or neurologically intact survival data for similar patients who did not undergo EDT) was available for the PICO questions of interest. RESULTS The 72 included studies provided 10,238 patients who underwent EDT. Patients presenting pulseless after penetrating thoracic injury had the most favorable EDT outcomes both with (survival, 182 [21.3%] of 853; neurologically intact survival, 53 [11.7%] of 454) and without (survival, 76 [8.3%] of 920; neurologically intact survival, 25 [3.9%] of 641) signs of life. In patients presenting pulseless after penetrating extrathoracic injury, EDT outcomes were more favorable with signs of life (survival, 25 [15.6%] of 160; neurologically intact survival, 14 [16.5%] of 85) than without (survival, 4 [2.9%] of 139; neurologically intact survival, 3 [5.0%] of 60). Outcomes after EDT in pulseless blunt injury patients were limited with signs of life (survival, 21 [4.6%] of 454; neurologically intact survival, 7 [2.4%] of 298) and dismal without signs of life (survival, 7 [0.7%] of 995; neurologically intact survival, 1 [0.1%] of 825). CONCLUSION We strongly recommend that patients who present pulseless with signs of life after penetrating thoracic injury undergo EDT. We conditionally recommend EDT for patients who present pulseless and have absent signs of life after penetrating thoracic injury, present or absent signs of life after penetrating extrathoracic injury, or present signs of life after blunt injury. Lastly, we conditionally recommend against EDT for pulseless patients without signs of life after blunt injury. LEVEL OF EVIDENCE Systematic review/guideline, level III.

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%).