Evaluation of a new automated quantitative d-dimer, Advanced D-Dimer, in patients suspected of venous thromboembolism.

The objective of our study was to evaluate the performance characteristics of a new automated d-dimer, the Advanced D-Dimer (Dade Behring Inc., Deerfield, IL) for use in the diagnosis of venous thromboembolism (VTE). To do this we compared the Advanced D-Dimer to existing d-dimer methods using established target cut-off values in patients suspected of VTE who were to undergo definitive radiographic studies for VTE. We studied hospitalized patients and outpatients who were suspected of having VTE and who had whole blood d-dimer performed. The patients who underwent a diagnostic study for VTE had their D-dimer results used to determine sensitivity, specificity and negative predictive values. There was relatively poor correlation between the Advanced D-Dimer and D-Dimer Gold (r = 0.63; t-test: P < 0.005) and Asserachrome D-Di (r = 0.58; t-test: P < 0.005). The Advanced D-Dimer target cutoff values for excluding VTE in hospitalized and outpatients were < or = 1800 microg/L and < or = 1500 microg/l respectively. There were 139 patients suspected with pulmonary embolism (PE) and 328 evaluated for deep vein thrombosis (DVT). There were 24 patients with PE, and 43 with DVT. The Advanced D-Dimer had comparable sensitivity, specificity and negative predictive values (96, 43, 98% for PE and 96, 48, 99% for DVT respectively) to other d-dimer methods used for that purpose. We conclude that the Advanced D-Dimer correlates relatively poorly with enzyme-linked immunosorbent assay methods. This poor correlation is likely due to incorrect reporting units and concentration. When these factors are corrected correlations improved. Compared to existing d-dimer methods used for VTE exclusion, the high sensitivity and negative predictive value would suggest that this method can be used as part of a diagnostic algorithm for the exclusion of PE and DVT.

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.

Biochemical basis for the hypercoagulable state seen in Cushing syndrome; discussion 1006-7.

HYPOTHESIS: Cushing syndrome (CS) is associated with a hypercoagulable state that results in a 4-fold increase in the incidence of pulmonary embolism, deep venous thrombosis, and a 4-fold mortality rate compared with the general population. The incidence of CS in humans is approximately 2 to 5 per million per year, whereas in dogs it is much higher. The clinical complications of CS in humans are also manifested in dogs. We used a dog model of CS to better define the biochemical basis for the hypercoagulable state seen in the disease. DESIGN: A consecutive sample of dogs with CS and a cohort of healthy control dogs identified at a "well-dog check" were enrolled. All dogs underwent blood assays to identify the levels of procoagulant factors, natural antithrombotics, and the degree of ongoing activation of the coagulation cascade. SETTING: University veterinary medical teaching hospital. RESULTS: A total of 86 dogs were enrolled, 56 with CS and 30 control dogs. Levels of procoagulation factors II, V, VII, IX, X, XII, and fibrinogen were significantly increased in dogs with CS (P<.05). The natural antithrombotic antithrombin was significantly decreased in dogs with CS (P<.02). Thrombin-antithrombin complexes, a marker of subclinical thrombosis, were significantly increased in dogs with CS (P<.05). CONCLUSIONS: The hypercoagulable state of CS is demonstrated by an increase in thrombin-antithrombin complexes. This hypercoagulable state may be caused in part by (1) an elevation of procoagulant factors, and (2) a decrease in antithrombin. Because of the similar clinical and biochemical changes between dogs with CS and humans, this canine model may be a useful tool for the future study of the hypercoagulable state in CS.

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.

Systemic coagulation and fibrinolysis after laparoscopic and open gastric bypass.

HYPOTHESIS: Laparoscopic gastric bypass (GBP) induces a postoperative hypercoagulable state that is similar or reduced compared with open GBP. SETTING: University hospital. PATIENTS: Between May 1999 and June 2000, 70 patients were randomly assigned to laparoscopic (n = 36) or open (n = 34) GBP. Deep venous thrombosis (DVT) prophylaxis consisted of antiembolism stockings and sequential pneumatic compression devices. MAIN OUTCOME MEASURES: Plasminogen, thrombin-antithrombin complex (TAT), prothrombin fragment 1.2 (F1.2), fibrinogen, D-dimer, antithrombin III (AT), and protein C levels were measured at baseline and at 1, 24, 48, and 72 hours postoperatively. A venous duplex examination of both lower extremities was performed preoperatively and between the third and fifth day postoperatively. RESULTS: The 2 groups were similar in age, weight, and body mass index. Plasminogen levels decreased, and TAT, F1.2, and fibrinogen levels increased after laparoscopic and open GBP. There was no significant difference in these levels between groups. D-dimer levels increased in both groups, but the levels were significantly higher after open GBP than after laparoscopic GBP (P<.01). Antithrombin III and protein C levels decreased in both groups. The reduction of AT (at 1 hour) and protein C (at 72 hours) was significantly less after laparoscopic GBP than after open GBP (P<.05). Postoperative venous duplex examination revealed DVT in 1 (2.9%) of 34 patients after open GBP but in none of 36 patients after laparoscopic GBP. One patient developed pulmonary embolism after open GBP. CONCLUSIONS: Laparoscopic GBP induces a hypercoagulable state similar to that of open GBP. Our findings suggest that DVT prophylaxis should be used during laparoscopic GBP as in open GBP.

Anticoagulation of children undergoing cardiopulmonary bypass is overestimated by current monitoring techniques.

HYPOTHESIS: Children who undergo cardiopulmonary bypass (CPB) are proportionally more hemodiluted than adults who undergo CPB. Current methods of monitoring high-dose heparin sulfate anticoagulation are dependent on fibrinogen level. Because of the decreased fibrinogen levels in children, current methods of monitoring heparin anticoagulation overestimate their level of anticoagulation. DESIGN: Prospective controlled trial. MAIN OUTCOME MEASURE: Production of thrombin (adequacy of anticoagulation). METHODS: Children and adults undergoing cardiac surgery who received CPB were anticoagulated in the standard fashion as directed by activated clotting time (ACT) results. Each subject had blood sampled at baseline; heparinization; start of the CPB; CPB at 30, 60, and 90 minutes; and at termination of CPB. Samples were used to assess anticoagulation with the Heparin Management Test (less dependent on fibrinogen level than ACT). We also assessed 2 subclinical markers of thrombosis, thrombin-antithrombin complexes and prothrombin fragment F1.2; a marker of procoagulant reserve, fibrinogen; the natural antithrombotic, antithrombin; and heparin concentration. RESULTS: Ten children and 10 adults completed the study. Children had lower fibrinogen levels than adults throughout CPB (P<.05). All adults had both therapeutic ACT and Heparin Management Test levels measured throughout CPB. Although children had therapeutic ACT levels, their Heparin Management Test levels were subtherapeutic while undergoing CPB. The children had significantly higher thrombin-antithrombin complexes and prothrombin fragment F1.2 than adults, indicating ongoing thrombin production (P<.01). The increases in thrombin-antithrombin complexes and prothrombin fragment F1.2 in children were inversely proportional to their weight. CONCLUSIONS: Children undergoing CPB with heparin dosing adjusted to optimize the ACT manifest inadequate anticoagulation (ongoing thrombin formation). High-dose heparin anticoagulation therapy in children undergoing CPB should be directed by tests (like the Heparin Management Test) that are less dependent on fibrinogen level than ACT.

A comparison of point-of-care instruments designed for monitoring oral anticoagulation with standard laboratory methods.

Our study compared point-of-care (POC) device monitoring with traditional clinical laboratory methods device of patients on oral anticoagulant therapy. The POC devices used in the study were Coumatrak, CoaguChek, CoaguChek Plus, Thrombolytic Assessment System (TAS) PT-One, TAS PTNC, TAS PT, Hemachron Jr. Signature, ProTime Microcoagulation System, and Medtronics ACT II. The clinical laboratory method used thromboplastins with different ISI values: Innovin and Thromboplastin C Plus (TPC). All POC INRs showed strong correlation with both laboratory methods, with correlation coefficients of >0.900. All POC methods demonstrated a significant (p <0.05) difference in INR values, except the TAS PTNC and ACT II INRs (p: 0.12 and 0.71 respectively) when compared with Innovin INRs. All POC INRs were significantly different from TPC generated INRs (p <0.05). Comparisons of the POC INRs to the group mean of the POC methods, show higher correlation (R>0.93), but there were still significant (p<0.05) differences noted between the POC group INR mean and CoaguChek Plus, ACT II, TAS PT-One, TAS PTNC, and Hemachron Jr Signature INRs. These data indicate that POC INR biases exist between laboratory methods and POC devices. Until a suitable whole blood INR standardization method is available, we conclude that clinicians using point-of-care anticoagulation monitoring should be aware of differences between POC and parent laboratory values.

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.

A new method for measuring D-dimer using immunoturbidometry: a study of 255 patients with suspected pulmonary embolism and deep vein thrombosis.

D-Dimer testing has been suggested as a non-invasive method for the exclusion of pulmonary embolism (PE) and deep vein thrombosis (DVT). In this study, we compared a new method, the Miniquant D-dimer (Biopool International, Ventura, California, USA) to other previously validated D-dimer methods used for the purpose. Patients who were undergoing a definitive diagnostic study for thromboembolism had a blood sample drawn at that time. A whole-blood D-dimer (SimpliRed; Agen Biomedical Ltd, Brisbane, Australia) test was performed, and residual plasma was frozen and later analyzed using two enzyme-linked immunosorbent assay (ELISA) methods (D-dimer Gold; Agen, and Asserachrome D-Di; Stago International, Parsippany, New Jersey, USA) and the Miniquant D-dimer. Once all samples were analyzed, the correlation and accuracy of the Miniquant was compared with the ELISA method using Spearman's regression and Dunn's multiple paired comparison. All D-dimer methods were compared with radiographic studies. The data was analyzed collectively and segregated into in-patient (n = 112) and out-patient (n = 143) populations. The Miniquant D-dimer sensitivity, specificity and negative predictive value (NPV) for all patients were 95, 21, and 94% for DVT, and 100, 26, and 100% for PE. This new D-dimer method demonstrates acceptable sensitivity in patients with PE and DVT and, based on the high NPV of this method, it can be used for the exclusion of thromboembolism.

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.

Bedside noninvasive detection of acute pulmonary embolism in critically ill surgical patients.

HYPOTHESIS: We hypothesized that late pulmonary dead space fraction (Fd(late)) would be a useful tool to screen for pulmonary embolism (PE) in a group of surgical patients, including patients who required mechanical ventilation and patients with adult respiratory distress syndrome. DESIGN: We prospectively calculated Fd(late) in patients with suspected PE who underwent pulmonary angiography. SETTING: University-based, level I trauma center. MAIN OUTCOME MEASURE: Ability of Fd(late) to identify patients with PE. RESULTS: Twelve patients had 14 angiograms for suspected PE. The Fd(late) was 0.12 or above in all 5 patients who had PE; 4 required mechanical ventilation. The Fd(late) values were below 0.12 in 8 of 9 patients without PE. Four patients had adult respiratory distress syndrome. The Fd(late) had 100% sensitivity and 89% specificity for the detection of PE. CONCLUSIONS: The Fd(late) is a valuable tool for bedside screening of PE in surgical patients. We were able to accurately detect all PEs.

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.