Testing for Substance Use in Trauma Patients

HYPOTHESIS

Only a fraction of trauma patients are being tested for substance use, and the proportion of those tested may have decreased over time.

DESIGN

Retrospective review of longitudinal data.

SETTING

National Trauma Data Bank.

PATIENTS

Individuals aged 15 to 50 years admitted with injuries from 1998 to 2003.

MAIN OUTCOME MEASURES

The primary outcomes of interest are the incidence of drug and alcohol testing and the results of these tests. The primary exposure of interest is year of admission.

RESULTS

Half of patients admitted with injuries are being tested for alcohol use, and half of these patients have positive test results. Only 36.3% of patients admitted with injuries are tested for drug use, and 46.5% of these patients have positive test results. There have been no significant trends for either alcohol testing or results in the past 6 years. Compared with 1998, patients are significantly less likely to be tested for drugs, but more likely to have positive test results.

CONCLUSIONS

Only a small proportion of patients who are admitted with injuries are tested for substance use. The proportion of patients tested for drugs has decreased significantly during the past 6 years. Routine testing would maximize identification of patients who may benefit from interventions. Several obstacles exist to routine screening, including legal and physician-related barriers. Future efforts to facilitate routine testing of trauma patients for substance use should concentrate on protecting patient confidentiality and educating physicians on the techniques and benefits of brief interventions.

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.

Performance of abdominal ultrasonography in blunt trauma patients with out-of-hospital or emergency department hypotension

STUDY OBJECTIVES

We determine the test performance of abdominal ultrasonography for detecting hemoperitoneum in blunt trauma patients with out-of-hospital or emergency department (ED) hypotension.

METHODS

We reviewed the medical records of all blunt trauma patients hospitalized at a Level I trauma center. Patients were included if they were older than 6 years and had out-of-hospital or ED hypotension (systolic blood pressure < or =90 mm Hg) and underwent ED ultrasonography. The initial interpretation of the abdominal ultrasonography was recorded, including the presence or absence of intraperitoneal fluid and the specific location of such fluid. Presence or absence of intra-abdominal injury was determined by abdominal computed tomography scan, laparotomy, or clinical follow-up.

RESULTS

Four hundred forty-seven patients with a mean age of 36.0+/-17.5 years were enrolled. One hundred forty-eight (33%) patients had intra-abdominal injuries, and 116 (78%) of these patients had hemoperitoneum. Abdominal ultrasonography had the following test performance for detecting patients with intra-abdominal injury and hemoperitoneum: sensitivity 92/116 (79%; 95% confidence interval [CI] 71% to 86%), specificity 316/331 (95%; 95% CI 93% to 97%), positive predictive value 92/107 (86%; 95% CI 78% to 92%), and negative predictive value 316/340 (93%; 95% CI 90% to 95%). The positive likelihood ratio was 15.8, and the negative likelihood ratio was 0.22. One hundred five (91%) of the 116 patients with intra-abdominal injuries and hemoperitoneum underwent a therapeutic laparotomy. Abdominal ultrasonography demonstrated intraperitoneal fluid in 87 (sensitivity 83%; 95% CI 74% to 90%) of these 105 patients.

CONCLUSION

Of patients with out-of-hospital or ED hypotension, abdominal ultrasonography identifies most patients with hemoperitoneum and intra-abdominal injuries. Hypotensive patients with negative abdominal ultrasonography results, however, must be further evaluated for sources of their hypotension, including additional abdominal evaluation, once they are hemodynamically stabilized.

Femur fractures and lung complications: a prospective randomized study of reaming

Reaming the intramedullary canal during fixation of femoral shaft fractures may contribute to pulmonary morbidity in patients with trauma. The purpose of our study was to compare acute and late pulmonary complications after reamed or nonreamed nailing of femur fractures. Patients who had femoral shaft fractures were randomized prospectively to a reamed (n = 41) or nonreamed (n = 41) femoral nailing group. Arterial blood gases were measured before and after femur fixation. Ratios of PaO2/FiO2 and alveolar arterial gradients were calculated. Pulmonary complications (acute respiratory distress syndrome) (ARDS), pneumonia, and respiratory failure) were monitored. Age, gender, fracture site, fracture type, time to nailing, length of operation, Injury Severity Score, and Abbreviated Injury Scale-thorax were similar for the two groups. No significant differences were observed in the ratio of PaO2/FiO2 ratios or alveolar arterial (A-a) gradients before and after nailing. The overall incidence of pulmonary complications was 14.6% (eight patients who had reamed nailing and four patients who had nonreamed nailing), and given the sample size, definitive conclusions could not be reached because of inadequate statistical power. We were unable to document differences in pulmonary physiologic response or clinical outcome between patients having reamed and nonreamed femoral nailing. This study may serve as a pilot investigation for other clinical investigations.

Trauma and Emergency Surgery: An Evolutionary Direction for Trauma Surgeons

BACKGROUND

The success of nonoperative management of injuries has diminished the operative experience of trauma surgeons. To enhance operative experience, our trauma surgeons began caring for all general surgery emergencies. Our objective was to characterize and compare the experience of our trauma surgeons with that of our general surgeons.

METHODS

We reviewed records to determine case diversity, complexity, time of operation, need for intensive care unit care, and payor mix for patients treated by the trauma and emergency surgery (TES) surgeons and elective practice general surgery (ELEC) surgeons over a 1-year period.

RESULTS

TES and ELEC surgeons performed 253 +/- 83 and 234 +/- 40 operations per surgeon, respectively (p = 0.59). TES surgeons admitted more patients and performed more after-hours operations than their ELEC colleagues. Both groups had a mix of cases that was diverse and complex.

CONCLUSION

Combining the care of patients with trauma and general surgery emergencies resulted in a breadth and scope of practice for TES surgeons that compared well with that of ELEC surgeons.

Videotape review leads to rapid and sustained learning

BACKGROUND

Performance review using videotapes is a strategy employed to improve future performance. We postulated that videotape review of trauma resuscitations would improve compliance with a treatment algorithm.

METHODS

Trauma resuscitations were taped and reviewed during a 6-month period. For 3 months, team members were given verbal feedback regarding performance. During the next 3 months, new teams attended videotape reviews of their performance. Data on targeted behaviors were compared between the two groups.

RESULTS

Behavior did not change after 3 months of verbal feedback; however, behavior improved after 1 month of videotape feedback (P <0.05) and total time to disposition was reduced by 50% (P <0.01). This response was sustained for the remainder of the study.

CONCLUSIONS

Videotape review can be an important learning tool as it was more effective than verbal feedback in achieving behavioral changes and algorithm compliance. Videotape review can be an important quality assurance adjunct, as improved algorithm compliance should be associated with improved patient care.

Does tachycardia correlate with hypotension after trauma?

BACKGROUND

Tachycardia is believed to be closely associated with hypotension and is often listed as an important sign in the initial diagnosis of hemorrhagic shock, but the correlation between heart rate and hypotension remains unproved.

STUDY DESIGN

Data were collected from all trauma patients, 16 to 49 years old, presenting to our university-based trauma center between July 1988 and January 1997. Moribund patients with a systolic blood pressure < or =50 or heart rate < or = 40 and patients with significant head or spinal cord injuries were excluded. Tachycardia was defined as a heart rate >or= 90 and hypotension as a systolic blood pressure < 90.

RESULTS

Hypotension was present in 489 of the 14,325 admitted patients that met the entry criteria. Of the hypotensive patients, 35% (169) were not tachycardic. Tachycardia was present in 39% of patients with systolic blood pressure 120 mmHg. Hypotensive patients with tachycardia had a higher mortality (15%) compared with hypotensive patients who were not tachycardic (2%, P = 0.003). Logistic regression analysis revealed tachycardia to be independently associated with hypotension (p = 0.0004), but receiver operating curve analysis demonstrated that the sensitivity and specificity of heart rate for predicting hypotension is poor.

CONCLUSIONS

Tachycardia is not a reliable sign of hypotension after trauma. Although tachycardia was independently associated with hypotension, its sensitivity and specificity limit its usefulness in the initial evaluation of trauma victims. Absence of tachycardia should not reassure the clinician about the absence of significant blood loss after trauma. Patients who are both hypotensive and tachycardic have an associated increased mortality and warrant careful evaluation.

Is there a relationship between trauma center volume and mortality?

BACKGROUND

The guidelines for Level I trauma center verification require 1,200 admissions per year. Several studies looking at the relationship between hospital volume and outcomes after injury have reached conflicting conclusions. The goal of our study was to examine the relationship between patient volume and outcomes (mortality and length of hospital stay) in California's trauma centers.

METHODS

Data for patients >or= 18 years old admitted after injury (n = 98,245) to a Level I or II trauma center (n = 38) in 1998 and 1999 were obtained from the Patient Discharge Data of the State of California. Hospital volume was derived from the annual number of admissions per center, and covariates including age, sex, mechanism of injury, Injury Severity Score, and trauma center designation were analyzed.

RESULTS

Hospital volume was not a significant predictor of death or length of hospital stay. More severely injured patients appeared to have worse outcomes at the highest volume centers.

CONCLUSION

In our study, hospital volume was not a good proxy for outcome. Low-volume centers appeared to have outcomes that were comparable to centers with higher volumes. Perhaps institutional outcomes rather than volumes should be used as a criterion for trauma center verification.

Reevaluation of diagnostic procedures for transmediastinal gunshot wounds

BACKGROUND

Little controversy surrounds the treatment of hemodynamically unstable patients with transmediastinal gunshot wounds (TMGSWs). These patients generally have cardiac or major vascular injuries and require immediate operation. In hemodynamically stable patients, debate surrounds the extent and order of the diagnostic evaluation. These patients can be uninjured, or can have occult vascular, esophageal, or tracheobronchial injuries. Evaluation has traditionally often included angiography, bronchoscopy, esophagoscopy, esophagography, and pericardial evaluation (i.e., pericardial window) for all hemodynamically stable patients with TMGSWs. Expansion of the use of computed tomographic (CT) scanning in penetrating injury led to a modification of our protocol. Currently, our TMGSW evaluation algorithm for stable patients consists of chest radiograph, focused abdominal sonography for trauma, and contrast-enhanced helical CT scan of the chest with directed further evaluation. The purpose of this study is to evaluate the efficiency of contrast-enhanced helical CT scan for evaluating potential mediastinal injuries and to determine whether patients can be simply observed or require further investigational studies.

METHODS

Medical records of hemodynamically stable patients admitted with TMGSWs over a 2-year period were reviewed for demographics, mechanism of injury, method of evaluation, operative interventions, injuries, length of stay, and complications. CT scans were considered positive if they contained a mediastinal hematoma or pneumomediastinum, or demonstrated proximity of the missile track to major mediastinal structures.

RESULTS

Twenty-two stable patients were studied. CT scans were positive in seven patients. Directed further diagnostic evaluation in those seven patients revealed two patients who required operative intervention. Sixty-eight percent of patients had negative CT scans and were observed in a monitored setting without further evaluation. There were no missed injuries. The hospital charges generated with the CT scan-based protocol are significantly less than with the standard evaluation.

CONCLUSION

Contrast-enhanced helical CT scanning is a safe, efficient, and cost-effective diagnostic tool for evaluating hemodynamically stable patients with mediastinal gunshot wounds. Positive CT scan results direct the further evaluation of potentially injured structures. Patients with negative results can safely be observed in a monitored setting without further evaluation.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The 'one-shot' intravenous pyelogram: is it indicated in unstable trauma patients before celiotomy?

Although contrast studies are valuable in assessing renal function and identifying injury in trauma victims, we questioned the use of "one-shot" intravenous pyelograms (IVPs) in unstable patients. Retrospective review of 926 IVPs performed over 4.5 years identified 239 preoperative "one-shot" IVPs in patients for whom evaluation in the radiology suite was felt to be unsafe. Of these IVPs, 53 had abnormal findings and 183 had normal findings. Three patients' records were lost. In the 53 patients with abnormal IVP results, injuries were confirmed at surgery in 39. In three cases, an abnormal appearing IVP provided the only indication for renal exploration leading to nephrectomy or revascularization. In the remaining 14 patients with abnormal IVPs, the kidneys were found to be normal at surgery. In the 183 patients with normal IVPs, 14 had injuries that required nephrectomy, renal vein ligation, renorrhaphy, or perinephric drainage. The IVP assessment of contralateral renal function played no role in the decision to perform nephrectomy.

CONCLUSIONS

Eight percent of patients with normal IVP findings had renal injuries not detected by "one-shot" IVP, and 26% of patients with abnormal IVP findings had no intraoperative evidence of renal injury. Delaying definitive therapy to obtain a preoperative "one-shot" IVP in an unstable patient is not warranted.

Hypertonic saline (7.5%) versus mannitol: a comparison for treatment of acute head injuries

Hypertonic saline (7.5% NaCl = HS) was compared with 20% mannitol (MAN), for the treatment of increased intracranial pressure (ICP), in a large animal model of head injury. Sheep were instrumented for hemodynamic and ICP monitoring and fluid administration. Elevated ICP (20-25 mm Hg) was produced by inflating an epidural balloon for 1 hour. Animals were then given a bolus of 250 mL of either HS (n = 7) or MAN (n = 7) and monitored for 2 hours. No significant differences in hemodynamic variables were noted between groups. The ICP decreased to the same degree in both groups during the 2 hours of observation (HS = 11 +/- 3.8 mm Hg; MAN = 8 +/- 2 mm Hg). Brain water contents were also similar (HS = 3.68 +/- 0.09 mL H2O/g dry wt; MAN = 3.83 +/- 0.08 mL H2O/g dry wt). The 7.5% NaCl was equally effective in treating elevated ICP caused by a space-occupying lesion when compared with 20% mannitol. Hypertonic saline has the additional benefit of rapid cardiovascular resuscitation of associated hemorrhagic shock with small-volume infusion.

Secondary survey following blunt trauma: a new role for abdominal CT scan

Computerized tomographic (CT) scanning for blunt abdominal trauma has focused on initial emergency department evaluation. At our institution, CT scanning is often used on a delayed basis for unexplained drops in hematocrit, investigation of bony injuries, or subtle abdominal findings. We reviewed 268 such scans. Over 32 months, 487 CT scans were done for 5258 blunt trauma admissions. Of these scans, 268 (55%) were done 8-72 hours after admission on patients under observation. Scanning indications were a falling hematocrit (67%), associated injuries (28%), and abdominal tenderness (5%). Fifty of the 268 scans (19%) were positive for intra-abdominal abnormalities. Pleural effusions were seen in 82 (31%). Sixteen abdominal explorations were done. There was no difference in the pre-scan hematocrit drop in patients with normal scans (6.6%), positive scans (6.8%), and those who were explored (6.4%). There was one false positive (0.4%) and two false negative scans (0.8%). Conclusions. (1) A significant number of occult injuries, some life threatening, are detected by delayed CT scans. (2) Hematocrit drop under observation is not a good predictor of occult intra-abdominal injury. (3) Delayed CT scanning for occult abdominal injury is cost effective.

Nuclear magnetic resonance as a measure of cerebral metabolism: effects of hypertonic saline resuscitation

Fears of central nervous system dysfunction from acute hypernatremia and hyperosmolarity with hypertonic saline resuscitation are often cited. We used high-energy phosphate nuclear magnetic resonance to investigate resuscitation effects on cerebral metabolism. Rats were instrumented for hemodynamic monitoring and fluid infusion and a phosphorus surface coil placed on their skulls. After shimming, baseline spectra were obtained. Animals were then bled for one hour to a mean arterial pressure (MAP) of 45 mm Hg, followed by resuscitation for one hour to a MAP of 75 mm Hg with lactated Ringer's (LR, n = 17) or 7.5% hypertonic saline (HS, n = 25). Spectra were obtained again and analyzed for the ratio of high-energy phosphocreatine (PCr) to low-energy inorganic phosphate (Pi). Intracellular hydrogen ion concentration [H+] was calculated from the PCr/Pi shift. [table: see text]

CONCLUSIONS

(1) Hypertonic saline results in a decreased intracellular pH compared with LR without associated changes in high-energy phosphate metabolism. (2) Decreases in pH may be the result of cell dehydration rather than metabolic dysfunction.

Combined hemorrhagic shock and head injury: effects of hypertonic saline (7.5%) resuscitation

Hypertonic saline resuscitation was compared to isotonic fluid resuscitation in a large animal model combining hemorrhagic shock with head injury. Sheep were subjected to a freeze injury of one cerebral hemisphere as well as 2 hours of hypotension at a mean arterial pressure (MAP) of 40 mm Hg. Resuscitation was then carried out (MAP = 80 mm Hg) for 1 hour with either lactated Ringer's (LR, n = 6) or 7.5% hypertonic saline (HS, n = 6). Hemodynamic parameters and intracranial pressure (ICP) were followed. At the end of resuscitation brain water content was determined in injured and uninjured hemispheres. No differences were detected in cardiovascular parameters; however, ICPs were lower in animals resuscitated with HS (4.2 +/- 1.5 mm Hg) compared to LR (15.2 +/- 2.2 mm Hg, p less than 0.05). Additionally, brain water content (ml H2O/gm dry weight) in uninjured brain hemispheres was lower after HS resuscitation (HS = 3.3 +/- 0.1; LR = 4.0 +/- 0.1; p less than 0.05). No differences were detected in the injured hemispheres. We conclude that hypertonic saline abolishes increases in ICP seen during resuscitation in a model combining hemorrhagic shock with brain injury by dehydrating areas where the blood-brain barrier is still intact. Hypertonic saline may prove useful in the early management of multiple trauma patients.