Hypothermia induces T-cell production of immunosuppressive cytokines.

BACKGROUND: Hypothermia is associated with increased postoperative infectious complications. We hypothesized that hypothermia suppresses the inflammatory response by altering T-cell cytokine production from a proinflammatory to an antiinflammatory profile, thus explaining the increased susceptibility to infectious complications associated with perioperative hypothermia. METHODS: Forty rats were randomized to either a Hypothermia (30 degrees C) or Control (38 degrees C) group. Blood samples taken at baseline and after 8 h of thermoregulation were stimulated with phorbol 12-myristate 13-acetate and ionomycin. Interleukin (IL)-2 receptor expression and intracellular IL-10 production were measured using monoclonal antibodies and flow cytometry in CD4 and CD8 T cells. Differences in IL-10 production and IL-2 receptor expression for stimulated samples in the Hypothermia and Control groups were compared. RESULTS: Stimulated CD4 cells demonstrated an antiinflammatory cytokine expression profile after hypothermia. Intracellular IL-10 production increased in the Hypothermia group but remained the same in the Control group (% change = 40 [3,87] and 2 [-36,26], respectively; P = 0.043). The increase in IL-2 receptor expression observed in the control group was suppressed after hypothermia (% change = 12[8,30] and 1 [-3,13], respectively; P = 0.026). We observed a greater increase in IL-10 production by CD8 cells from hypothermic animals than in those from control animals (% change = 41 [-8,90] and -4 [-40,5], respectively; P = 0.019). CD8 IL-2 receptor expression in hypothermic animals was similar to that of control animals (% change = 23 [-7,37] vs 25 [2,80], respectively; P = 0.32). CONCLUSIONS: Hypothermia induced an antiinflammatory T-cell cytokine profile.

Platelet activation and function after trauma.

BACKGROUND: Abnormal hemostasis is associated with many of the complications of trauma-associated morbidity and mortality. Platelets are integral in the maintenance of hemostasis. METHODS: Samples were obtained from 100 trauma patients on arrival at the emergency room (initial time) and at 24, 48, and 72 hours later. Samples were also obtained from 10 healthy controls at the same time intervals. Using flow cytometry, three parameters were used to measure platelet activation: platelet microparticles, expression of P-selectin (CD62P), and expression of the activated conformation of glycoprotein IIb-IIIa (PAC-1 binding). Platelet function was measured using a platelet function analyzer (PFA-100, Dade International Inc., Miami, FL). RESULTS: One hundred trauma patients were enrolled. The average age was 40 years, 75% were men, and 84% had blunt injuries. The mean Injury Severity Score was 22.3 +/- 10.9 (mean +/- SD) and the average Glasgow Coma Scale score was 11 +/- 4. All three platelet activation parameters were increased in trauma patients versus controls for all time periods (p < 0.001). Trauma patients had a trend toward a shorter initial collagen/epinephrine closure time versus controls (p = 0.096). Compared with the 24-, 48-, and 72-hour time intervals, initial collagen/epinephrine closure times were shortened (p < 0.001, p < 0.001, and p < 0.001). Platelet function returned to normal reference ranges within 24 hours but platelet activation parameters remained elevated at least 72 hours after initial trauma. In contrast, when trauma patients with and without brain injury were compared, brain injury patients had increased platelet activation but decreased platelet function (increased collagen/epinephrine closure times). In addition, there was a significant prolongation in collagen/epinephrine closure times for the 24-, 48-, and 72-hour time points in nonsurviving patients versus survivors. There was no association between platelet activation and function and other adverse outcomes including pulmonary embolism, deep venous thrombosis, and disseminated intravascular coagulation. CONCLUSION: Severe injury usually results in increased platelet activation and function. However, the combination of increased platelet activation with decreased function was associated with increased mortality.

Practical utility of the D-dimer assay for excluding thromboembolism in severely injured trauma patients.

BACKGROUND: We have advocated the use of a D-dimer assay to exclude the diagnosis of pulmonary embolism (PE) and deep venous thrombosis (DVT) in surgical and trauma patients suspected of having these diagnoses. Injury is known to increase D-dimer levels independent of thromboembolism. The purpose of this study was to assess the period after injury over which the D-dimer assay remains positive because of injury exclusive of thromboembolism. METHODS: We prospectively sampled the plasma of severely injured patients for D-dimer using an enzyme-linked immunosorbent assay method at admission; at hours 8, 16, 24, and 48; and at days 3, 4, 5, and 6. Patients were then screened for DVT with a routine duplex Doppler at day 7. Patients were followed for PE, adult respiratory distress syndrome, and disseminated intravascular coagulation. RESULTS: One hundred fifty-four patients (mean Injury Severity Score of 23) underwent a total of 1,230 D-dimer assays. Twenty-six (17%) had thromboembolism. Nine (6%) patients developed DVT, 2 (1%) developed PE, 13 (8%) developed disseminated intravascular coagulation, and 11 (7%) developed severe adult respiratory distress syndrome. None of the trauma patients with thromboembolism had a (false) negative D-dimer at or after the time of their thromboembolic complication. True-negative D-dimer results as a function of time from injury are: 0 hours, 18%; 8 hours, 16%; 16 hours, 17%; 24 hours, 22%; 48 hours, 37%; day 3, 34%; day 4, 32%; day 5, 30%; and day 6, 30%. The negative predictive value of the assay was 100%. D-dimer levels were significantly higher in those who developed a thromboembolic complication than in those who did not (independent of Injury Severity Score). CONCLUSION: These data serve to validate D-dimer as a means of excluding thromboembolism, specifically in patients with severe injury (100% negative predictive value). Before 48 hours after injury, however, the vast majority of these patients without thromboembolism had positive D-dimer assays. Because of the high false-positive rate early after severe injury, the D-dimer assay may be of little value before postinjury hour 48.

Abbreviated thoracotomy and temporary chest closure: an application of damage control after thoracic trauma.

HYPOTHESIS: Abbreviated thoracotomy, a damage-control strategy, improves survival in patients with metabolic exhaustion. DESIGN: Case series report. SETTING: University-based, level I trauma center. PATIENTS: All patients admitted to our trauma center with severe chest trauma in whom an abbreviated thoracotomy was performed between January 1, 1994, and January 1, 1998. INTERVENTIONS: Patients in whom an abbreviated thoracotomy was performed had their life-threatening thoracic injuries treated and had temporary closure of the incision. They were then resuscitated in the intensive care unit (ICU). Definitive care of injuries and formal chest closure were performed when physiological characteristics were normalized. MAIN OUTCOME MEASURES: Survival to discharge and postoperative complications. RESULTS: Of 10 787 patients admitted to the trauma center, 196 required thoracic operations. Eleven of these 196 patients underwent abbreviated thoracotomy; all patients survived to reach the ICU. Four died in the ICU within 24 hours of injury; the remaining 7 patients survived and were discharged. Based on their Trauma and Injury Severity Score, predicted mortality for our 11 patients was 59%; our mortality was 36%. Complications after abbreviated thoracotomy were similar to those seen after standard thoracotomy. CONCLUSIONS: Abbreviated thoracotomy is a useful strategy in the treatment of severe chest trauma. Its use in situations of metabolic exhaustion or planned reexploration may increase patient survival rates by expediting transfer of the patient from the operating room to the ICU, where homeostasis can be restored.

Hemothorax.

Hemothorax has been recognized as a clinical entity for centuries. However, the use of closed drainage has only recently been described in the last 50 years. Chest radiography remains the mainstay of diagnosis, however computed tomography and ultrasound are useful in some circumstances. The treatment of hemothorax is adequate drainage. Drainage allows for apposition of the visceral and parietal pleura, which aids hemostasis. Massive hemothorax and ongoing bleeding are indications for thoracotomy. Clotted hemothorax can be difficult to drain adequately with tube thoracostomy alone. Video assisted thoracic surgery (VATS) has proven most effective in obtaining adequate drainage if performed early in the patient's course.

Whole blood D-dimer assay: an effective noninvasive method to rule out pulmonary embolism.

BACKGROUND: The whole blood D-dimer assay has gained recognition as a noninvasive test to rule out pulmonary embolism (PE) in medical patients. METHODS: We performed a whole blood D-dimer assay in medical and surgical patients undergoing either pulmonary angiogram or pulmonary ventilation perfusion scan for suspected PE or duplex Doppler or venogram for suspected deep venous thrombosis (DVT). RESULTS: A total of 483 patients were enrolled; 16 were excluded because of an equivocal pulmonary ventilation perfusion scan. The 467 remaining patients had a mean age of 56 +/- 27 years. There were 258 women and 209 men. A total of 353 patients were admitted to a medical service and 114 to surgery/ trauma. A total of 82 patients (18%) developed thromboembolism: 20 had PE, and 62 had DVT. CONCLUSION: No surgical patient with PE or DVT (n = 27) had a negative D-dimer. A negative D-dimer result in a stable surgical patient should be considered conclusive evidence to rule out thromboembolism and, thus, negate the need for further diagnostic studies. In our surgical patients suspected of DVT or PE, had D-dimer been used, one third of the patients would have avoided an expensive or invasive diagnostic test.

Perihepatic packing of major liver injuries: complications and mortality.

HYPOTHESIS: Perihepatic packs used to control hemorrhage after liver injury increase the risk of complications and this risk increases the longer packs are left in place. DESIGN: Retrospective case series. SETTING: University level I trauma center. PATIENTS: Consecutive patients with hepatic injury. MAIN OUTCOME MEASURES: Liver-related complications (biliary leak and abscess), rebleeding, and mortality. RESULTS: One hundred twenty-nine of 804 patients with liver injuries were treated with perihepatic packing. Of the 69 who survived more than 24 hours, 75% lived to hospital discharge. Mortality rates were 14% and 30% in patients with and without liver complications, respectively (P = .23). Liver complication rates were similar (P = .83) when packs were removed within 36 hours (early [33%]) or between 36 and 72 hours (late [29%]) after they were placed; the rebleeding rate was greater in the early group (21% vs 4%; P<.001). CONCLUSIONS: Liver complications associated with perihepatic packing did not affect survival. Removing liver packs 36 to 72 hours after placement reduced the risk of rebleeding without increasing the risk of liver-related complications.

Increased use of prophylactic vena cava filters in trauma patients failed to decrease overall incidence of pulmonary embolism.

BACKGROUND: Recent studies have reported that placement of vena cava filters (VCFs) early after injury may decrease the incidence of pulmonary embolism (PE) in high-risk trauma patients. STUDY DESIGN: This was a retrospective review of all trauma patients with placement of VCFs admitted to a single level-1 trauma center between 1989 and 1997. Two cohorts corresponding to years of high or low prophylactic VCF use (PVCF) were compared. RESULTS: Records were reviewed for 299 trauma patients identified as having had placement of a VCE Two hundred forty-eight filters were placed before the diagnosis of PE. During years of low PVCF use, the overall PE incidence was 0.31%; during years of high PVCF use, the incidence of PE was higher at 0.48% (p = 0.045, chi-square). CONCLUSIONS: Increased use of PVCFs failed to decrease the overall rate of PE in our trauma patient population.

Field triage of the pulseless trauma patient.

HYPOTHESIS: Trauma patients who are pulseless at the scene of injury and whose electrical cardiac activity is less than 40 beats/min cannot be revived. DESIGN: Retrospective review. SETTING: University hospital, level I trauma center. PATIENTS: Pulseless trauma patients who had cardiopulmonary resuscitation at the scene, en route, or in the emergency department and presented between January 1, 1991, and July 1, 1996. MAIN OUTCOME MEASURE: Survival after traumatic cardiopulmonary arrest. RESULTS: Sixteen thousand seven hundred twenty-four trauma patients were admitted. The study cohort comprised 604 victims of traumatic cardiopulmonary arrest, 304 as a result of blunt injury and 300 as a result of penetrating injury. Transport time for the study patients was 11+/-6.1 minutes (mean +/- SD). Cardiopulmonary resuscitation was performed on them for 22+/-11 minutes. Three hundred four patients (50%) had resuscitative thoracotomy in the emergency department; 160 patients were taken to the operating room for further resuscitation and treatment of their injuries. Sixteen patients (2.6%) survived to discharge from the hospital; 7 had severe neurologic disabilities. No patient (0/212) with electrical asystole survived. Five of 134 patients with an initial electrical heart rate between 1 and 39 beats/min survived long enough to reach the intensive care unit but died within 48 hours (4 died within 24 hours). No patient survived to leave the hospital if the initial electrical heart rate was less than 40 beats/min. All 16 survivors had an initial heart rate of 40 beats/min or greater. CONCLUSION: Trauma victims who are pulseless and have asystole or agonal electrical cardiac activity (heart rate <40 beats/min) should be pronounced dead at the scene of injury.

Isolated transient loss of consciousness is an indicator of significant injury.

OBJECTIVE: To determine if isolated transient loss of consciousness is an indicator of significant injury. SETTING: University-based level I trauma center. DESIGN AND PATIENT: Phase 1 retrospective case series of all patients with trauma admitted directly from the emergency department to the operating room or an intensive care unit who had transient loss of consciousness as their only trauma triage criterion. Phase 2 prospective case series of all trauma patients transported by emergency medical system personnel with transient loss of consciousness as their only trauma triage criterion. MAIN OUTCOME MEASURES: Emergency operation and intensive care unit admission. RESULTS: Phase 1: From January 1, 1992, to March 31, 1995, we admitted 10255 patients with trauma. Three hundred seven (3%) met the enrollment criteria and were admitted to the operating room (n = 168) or intensive care unit (n = 139). Of these, 58 (18.9%) were taken to the operating room emergently to manage life-threatening injuries: 11 (4%) had craniotomies and 47 (15%) had non-neurosurgical operations. Phase 2: From July 1 to December 31, 1996, 2770 trauma patients were transported to our facility; 135 (4.9%) met the enrollment criteria. Forty-one (30.4%) of these required admission, and 6 (4.4%) were taken emergently to the operating room from the emergency department (1 [1%] for a craniotomy, 3 [2.2%] for intra-abdominal bleeding, and 2 [1.5%] for other procedures). Two (1.5%) of the 135 patients died. CONCLUSIONS: Patients with isolated transient loss of consciousness are at significant risk of critical surgical and neurosurgical injuries. These patients should be triaged to trauma centers or hospitals with adequate imaging, surgical, and neurosurgical resources.

Comparison of gastric mucosal pH and clinical judgement in critically ill patients.

OBJECTIVES: To compare gastric tonometry (pHi) with estimates of pHi in ill injured patients, and to correlate pHi with haemodynamic variables. DESIGN: Prospective, non-interventional study. SETTING: ICU of Level I trauma centre, USA. MAIN OUTCOME MEASURES: 154 gastric tonometry measurements were compared with physicians' estimates of adequacy of resuscitation. Resuscitation was categorised as inadequate (pHi < 7.35) or adequate (pHi> or = 7.35). Measured and estimated pHi were also compared with oxygen delivery, oxygen consumption, cardiac index, mixed venous O2 saturation, and critical illness scores. RESULTS: Estimated pHi was often higher than measured pHi in the judgement of all four surgical intensive care physicians. Measured pHi correlated positively with mixed venous O2 tension (r = 0.21). There were significant negative correlations between measured pHi and both oxygen delivery (r = -0.25) and oxygen consumption (r = 0.28). Estimated pHi correlated positively with mean arterial pressure (r = 0.21) and hospital day (r = 0.26); it correlated negatively with pulmonary arterial elastance (r = -0.35). CONCLUSION: Experienced intensive care physicians tended to overestimate visceral perfusion, which suggests that gastric tonometry adds useful information over and above routine haemodynamic indices. Arterial blood pressure and mixed venous oxygen saturation correlated better with measured pHi than with other indices of perfusion.

Use of cardiopulmonary bypass to salvage patients with multiple-chamber heart wounds.

BACKGROUND: The need for cardiopulmonary bypass in the treatment of penetrating heart injuries is debated. OBJECTIVES: To review our experience with penetrating heart injuries and determine the indications and outcome for cardiopulmonary bypass. DESIGN: Retrospective review. SETTING: A university-based, level I trauma center. PATIENTS: All victims of penetrating heart injury presenting between July 1, 1989, and December 31, 1995. METHODS: Medical records were reviewed for demographic and physiological data, operative findings, and outcome. RESULTS: Overall survival for 106 patients with penetrating heart injury was 55%. In an effort to resuscitate the heart, 4 patients with unresponsive cardiogenic shock were placed on cardiopulmonary bypass; none survived. Of 30 patients with multiple-chamber injuries, 11 presented with signs of life and 7 survived. Cardiopulmonary bypass was essential to repair complex injuries in 2 of the 7 survivors. CONCLUSION: Cardiopulmonary bypass was ineffective in salvaging patients with cardiogenic shock but was essential in some patients with complex multiple-chamber cardiac injuries that could not be exposed and repaired by other means.

Posttraumatic lymphocyte response: a comparison between peripheral blood T cells and tissue T cells.

BACKGROUND: T-cell response to trauma has been assessed primarily by sampling peripheral blood lymphocytes. We hypothesized that lymphocytes residing in tissue and traveling through lymph vessels are more likely to be activated by tissue injury and hemorrhage-induced hypoperfusion. We compared peripheral blood T-cell response with tissue or lymph T-cell response in an ovine model of multiple injury. METHODS: Anesthetized adult sheep instrumented with a chronic prefemoral lymph fistula were subjected to lower-extremity fractures, fixed-volume hemorrhage, resuscitation, and fracture stabilization. Peripheral blood and tissue T-cell receptor expression was determined at baseline and after injury. RESULTS: At baseline, we found significant differences in the expression of CD4, CD8, and L selectin between peripheral blood T cells and tissue T cells. After trauma, the percentage of tissue T cells expressing CD8 decreased from 19 +/- 9 to 14 +/- 5 (p < 0.05) and the percentage expressing gammadelta-TcR receptors decreased from 12 +/- 4 to 7 +/- 2 (p < 0.05). T-cell phenotype composition in peripheral blood was not affected by trauma. CONCLUSION: Peripheral blood T-cell composition differs from tissue T-cell composition before and after trauma. Trauma produced changes in tissue T-cell phenotypes but not in peripheral blood T-cell phenotypes.

Video-assisted thoracic surgery in the treatment of posttraumatic empyema.

BACKGROUND: Video-assisted thoracic surgery (VATS) appears to be replacing open thoracotomy for the treatment of posttraumatic thoracic complications. OBJECTIVE: To compare operative times, complication rates, and outcomes in patients who underwent VATS vs open thoracotomy. DESIGN: Retrospective review. SETTING: University hospital, level I trauma center. PATIENTS: Trauma patients who between December 1993 and May 1997 underwent open thoracotomy or VATS to drain a persistent thoracic collection. METHODS: Medical records were reviewed for demographic data, operative times, and clinical outcomes. RESULTS: Of the 524 trauma patients requiring tube thoracostomy, 22 underwent 23 procedures to drain empyema (17 VATS, 6 thoracotomies [based on surgeon preferencel). There were no differences in age, Injury Severity Score, or mechanism of injury between the 2 groups. Three patients who underwent VATS (18%) required conversion to open thoracotomy for adequate drainage. All remaining patients who underwent VATS had successful treatment of their empyema. Complication rates (VATS=29%, open thoracotomy=33%; P=.99), operative times (VATS=3.4+/-1.3 hours [mean+/-SD], open thoracotomy=3.0+/-1.5 hours; P=.46), postoperative epidural catheter use (VATS=31%, open thoracotomy=50%; P=.63), duration of chest tube drainage (VATS=5.1+/-1.7 days [mean+/-SD], open thoracotomy=4.5+/-1.5 days; P=.48), and hospital stay after the procedure (VATS=16+/-14 days [mean+/-SD], open thoracotomy=11+/-5 days; P=.39) were similar for both groups. CONCLUSIONS: Video-assisted thoracic surgery was a safe and effective operative strategy for the treatment of posttraumatic empyema. Therefore, because VATS has been shown in nontrauma patients to reduce morbidity and because it provides better cosmesis, we believe that it should be the initial operative approach to trauma patients with suspected posttraumatic empyema.

Percutaneous diagnostic peritoneal lavage using a Veress needle versus an open technique: a prospective randomized trial.

OBJECTIVE: To prospectively compare the speed, sensitivity, complications, and technical failures of percutaneous diagnostic peritoneal lavage (DPL) using a Veress needle versus open DPL. METHODS: One hundred seventy-six blunt trauma patients requiring DPL were prospectively randomized to undergo either open DPL using a standard technique or percutaneous DPL using an 18-gauge Veress needle to penetrate the peritoneal cavity, with the lavage catheter then being inserted over a guide wire. RESULTS: Mean time to successful placement of the lavage catheter for the percutaneous Veress needle technique was 2.73 minutes versus 7.28 minutes for the open DPL technique (p < 0.001). Sixteen percent of open lavage procedures took more than 11 minutes; the majority (60%) of Veress needle lavage procedures took less than 2 minutes. There were no false-negative findings in either group, and there was one false-positive result in each group. A wound infection after an open DPL was the only complication. Poor return of lavage fluid (<200 mL) accounted for most technical failures; this was more prevalent with the percutaneous method (11.2%) than with the open technique (3.8%) (p < 0.05). CONCLUSION: The percutaneous DPL method using a Veress needle is significantly faster than the open DPL method. The Veress needle lavage was as safe and as sensitive as the open lavage; however, technical failure occurred more frequently with the Veress needle lavage than with the open DPL.

Trauma patients 75 years and older: long-term follow-up results justify aggressive management.

BACKGROUND: Long-term survival rate and functional status after trauma for one of the fastest growing segments of the population, patients 75 years and older, is poorly documented. METHODS: Trauma patients 75 years and older who were discharged from our Level I trauma center between June 1988 and July 1992 (n = 279) were contacted by mail or phone. Public death records were used to identify patients who had died. A stepwise logistic regression analysis was performed to determine predictors of poor outcome (death within 6 months). Main outcome measures included mortality and self-assessed functional status. RESULTS: A minimum 4-year follow-up was obtained for 81% of the 279 study patients. The mean follow-up period was 5.4 +/- 1.1 years. Mean age at time of injury was 81 +/- 5 years (range, 75-101 years); mean Injury Severity Score was 9.4 +/- 7.7. At follow-up, 132 patients (47%) had died, 93 patients (33%) were contacted, and 54 patients (19%) could not be located. Twelve percent of patients survived less than 6 months after discharge. Poor survival was predicted by preexisting diseases (dementia, p = 0.001; hypertension, p = 0.02; and chronic obstructive pulmonary disease, p = 0.05) and not by age or severity of injury. The mean age of patients still living was 85 +/- 3.9 years (range, 79-99 years), and 77 of 93 patients were living in an independent setting (33 alone, 44 with spouse or family); of these, 57% reported no difficulties in performing 12 of 14 activities of daily living. CONCLUSION: Despite higher than expected mortality after discharge, aggressive management of trauma patients 75 years and older is justified by the favorable long-term outcome.

Ventilation in the trauma and surgical patient.

Changes in the understanding of the pathophysiology of ARDS and effects of mechanical ventilation with high pressures have led to treatment strategies that resulted in improved survival rates. The central principle in these strategies is to avoid ventilation induced lung injury by allowing the lungs to rest. A number of promising new treatments emphasizing this principle are under investigation. Physicians caring for patients who develop ARDS should make every effort to avoid alveolar overdistention by ventilating patients in the compliant portion of pressure-flow loop and avoid peak inspiratory pressures in excess of 40 cm H2O.

A prospective, randomized trial of intravenous fat emulsion administration in trauma victims requiring total parenteral nutrition.

OBJECTIVE: Intravenous fat infusions are a standard component of total parenteral nutrition (TPN). We studied the effects of withholding fat infusions in trauma patients requiring TPN. DESIGN: Polytrauma patients receiving TPN were randomized to receive a standard fat emulsion dose (L) or to have fat infusions withheld (NL) for the first 10 days of TPN. The two groups received the same amino acid and carbohydrate dose (isonitrogenous, nonisocaloric). MATERIALS AND METHODS: Clinical outcome parameters were measured. T-cell function was assessed by measuring lymphokine activated killer and natural killer cell activity. MEASUREMENTS AND MAIN RESULTS: Demographics including Injury Severity Score (27 +/- 8; 30 +/- 9) and APACHE II scores (23 +/- 6; 22 +/- 5) were similar for the L (n = 30) and NL (n = 27) groups, respectively. Differences (p < 0.05) were found in length of hospitalization (L = 39 +/- 24; NL = 27 +/- 16), intensive care unit length of stay (L = 29 +/- 22; NL = 18 +/- 12), and days on mechanical ventilation (L = 27 +/- 21; NL = 15 +/- 12). The L group had a higher number of infections (72 in 30) than the NL group (39 in 27) and T-cell function was depressed in this group. CONCLUSIONS: Intravenous fat emulsion infusions during the early postinjury period increased susceptibility to infection, prolonged pulmonary failure, and delayed recovery in critically injured patients. It is not clear whether the improved outcome in the NL group was directly related to withholding the fat infusions or due to the hypocaloric nutritional regimen (underfeeding) these patients received.

Hospital readmission after trauma: an analysis of outpatient complications.

BACKGROUND: Outpatient complications leading to hospital readmission after hospitalization for trauma have not been examined. METHODS: A retrospective chart review of all trauma victims admitted to a Level 1 trauma center from January of 1990 to January of 1995 was performed to characterize patients who required readmission after hospitalization for trauma. Risk factors for readmission were determined by stepwise regression analysis. RESULTS: Of 15,463 trauma admissions, 209 patients (1.4%) required readmission, 84% within 30 days, 71% within 14 days. Reasons for readmission included wound (29%), abdominal (29%), pulmonary (18%), and thromboembolic (19%) complications. Fifty of the patients (24%) readmitted with a complication required an operation. Risk factors for readmission included: operation during first hospitalization (p < 0.0001), penetrating injury (p = 0.0001), and advanced age (p = 0.0001). Injury Severity Score, length of hospitalization, and gender were not independent predictors of readmission. CONCLUSIONS: Outpatient complications leading to readmission after hospitalization for trauma are not common; however, many are serious and require operative intervention. Because most complications were identified by the second week after discharge, outpatient follow-up visits should be scheduled within 7 to 14 days. Based on our findings, we recommend protocols be established to ensure follow-up for trauma patients, especially those who have had an operation, were victims of penetrating injury, or those > 65 years of age.

Posttraumatic empyema. Risk factor analysis.

BACKGROUND: Empyema remains a distressing complication after thoracic injury. OBJECTIVE: To identify high-risk factors associated with the development of empyema. DESIGN: Retrospective cohort review. SETTING: University hospital, level I trauma center. PATIENTS: Trauma patients who required tube thoracostomy (TT) between January 1, 1991, and November 31, 1993 (n = 584). METHODS: Data (demographic characteristics, injuries, chest x-ray film reports, and setting of TT) were assessed using a stepwise logistic regression analysis to identify risk factors associated with the development of post-traumatic empyema. RESULTS: Empyema that required decortication developed in 25 patients (4%). Factors predictive of development of empyema were retained hemothorax (odds ratio, 12.5; 95% confidence interval, 0.96-163), pulmonary contusion (odds ratio, 6.3; 95% confidence interval, 1.53-25.8), and multiple chest tube placement (odds ratio, 2.5; 95% confidence interval, 1.91-3.28); factors not predictive of empyema were severity of injury, mechanism of injury, setting in which TT was performed, number of days chest tubes were in place, and antibiotic drugs at the time of TT. CONCLUSIONS: The extent of pulmonary injury (pulmonary contusion) is an important predictor of empyema development. Previously implicated factors such as setting in which a TT was performed and mechanism of injury did not correlate with the development of posttraumatic empyema. Based on the results of our study, we recommend early drainage of the pleural space with video-assisted thoracoscopic techniques in patients at risk of empyema, which may spare them the morbidity of a thoracotomy.