Lawrence Lottenberg

Blunt traumatic occult pneumothorax: is observation safe?--results of a prospective, AAST multicenter study.

BACKGROUND An occult pneumothorax (OPTX) is found incidentally in 2% to 10% of all blunt trauma patients. Indications for intervention remain controversial. We sought to determine which factors predicted failed observation in blunt trauma patients. METHODS A prospective, observational, multicenter study was undertaken to identify patients with OPTX. Successfully observed patients and patients who failed observation were compared. Multivariate logistic regression was used to identify predictors of failure of observation. OPTX size was calculated by measuring the largest air collection along a line perpendicular from the chest wall to the lung or mediastinum. RESULTS Sixteen trauma centers identified 588 OPTXs in 569 blunt trauma patients. One hundred twenty-one patients (21%) underwent immediate tube thoracostomy and 448 (79%) were observed. Twenty-seven patients (6%) failed observation and required tube thoracostomy for OPTX progression, respiratory distress, or subsequent hemothorax. Fourteen percent (10 of 73) failed observation during positive pressure ventilation. Hospital and intensive care unit lengths of stay, and ventilator days were longer in the failed observation group. OPTX progression and respiratory distress were significant predictors of failed observation. Most patient deaths were from traumatic brain injury. Fifteen percentage of patients in the failed observation group developed complications. No patient who failed observation developed a tension PTX, or experienced adverse events by delaying tube thoracostomy. CONCLUSION Most blunt trauma patients with OPTX can be carefully monitored without tube thoracostomy; however, OPTX progression and respiratory distress are independently associated with observation failure.

Pulmonary embolism prophylaxis with inferior vena cava filters in trauma patients: a systematic review using the meta-analysis of observational studies in epidemiology (MOOSE) guidelines

Prophylactic inferior vena cava filters (pIVCFs) for the prevention of pulmonary embolism (PE) are controversial. Current practice guidelines (EAST and ACCP) are based on the critical appraisal of observational studies. As a result, their recommendations are conflicting and may account for practice pattern variation. The purpose of this study is to critically review the available literature and ascertain the level of evidence both for and against the use of pIVCFs for PE prophylaxis in trauma patients. We searched PubMed and Web of Science for publications from 1950 until July 2010 that assessed the efficacy of PE prevention with pIVCFs in the trauma population. We followed the MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines for design, implementation, and reporting. The Newcastle-Ottawa Score was used for quality and comparability assessment. Seven observational studies met inclusion criteria for this meta-analysis, representing 1,900 patients. Only one study was published in this decade. The rate of PE was statistically lower in the IVCF group compared to a matched control group without IVCFs (OR 0.21, 95% CI 0.09–0.49). There was no significant difference in DVT. Using the MOOSE criteria these results show a decreased likelihood of PE among trauma patients who receive pIVCFs. Although these results could favor the placement of pIVCFs, the lack of contemporary use of pharmacologic prophylaxis across studies does not allow us to make firm conclusions either for or against the routine use of pIVCFs. Prospective randomized trials are needed to determine the role of pIVCFs in high-risk trauma patients.

Traumatic aortic injuries in the pediatric population

BACKGROUND/PURPOSE Blunt trauma is the leading cause of pediatric injury, but pediatric aortic injuries are rare. We undertook this study to investigate the demographics, treatment, and outcomes of children with blunt aortic injuries and report our experience over a 10-year period. METHODS After Institutional Review Board approval, a 10-year retrospective review of all pediatric patients admitted with blunt aortic injury was performed. Patient demographics, injury details and severity score (Injury Severity Score), treatment, and outcomes were recorded. RESULTS There were 11 children, with ages ranging from 7 to 19 years. The most common mechanism of injury was motor vehicle crashes (8). Initial computed tomography demonstrated all 11 injuries: 7 thoracic aortic (TA) and 4 abdominal aortic (AA) injuries. Associated injuries were common. The TA injuries included 4 transections, 2 intimal flaps, and 1 pseudoaneurysm. Three of these were managed nonoperatively. The AA injuries included 3 intimal flaps and 1 dissection. Three of these were also managed nonoperatively. There were no complications in the 4 children with AA or in the 3 children with TA managed nonoperatively. Complications in the 4 children undergoing operative repair of the TA included paraplegia, renal failure, recurrent laryngeal nerve injury, and pulmonary embolus. The mean hospital stay was 8 days. All children survived, with all but one discharged directly to home. CONCLUSIONS Blunt aortic injury in children is uncommon and is primarily associated with motor vehicle crashes. Injuries to the abdominal aorta were seen with restrained children vs those to the thoracic aorta that were seen in children who were unrestrained.

Differences in outcome between obese and nonobese patients following severe blunt trauma are not consistent with an early inflammatory genomic response.

Objectives:Obesity has been demonstrated to alter a number of acute and chronic medical conditions. The effect of obesity on severely injured patients, however, remains incompletely defined. We sought to unravel potential physiologic and genomic alterations induced by obesity in severely injured blunt trauma patients. Design:A retrospective review of clinical and genomic information contained in the Inflammation and the Host Response to Injury multicenter trauma-related database examining the relationship between body mass index and the early genomic response from peripheral blood leukocytes to patient outcome following severe blunt trauma was performed. Setting:Multicenter collaboration between university-based academic trauma centers. Patients:Severely injured blunt trauma patients enrolled in the database. Interventions:None. Measurements and Main Results:Univariate analysis of 455 severely injured trauma patients using the National Institutes of Health/World Health Organization body mass index classification system revealed significant increases in morbidity, including longer intensive care unit stays and a greater number of ventilator days, cardiac arrests, episodes of acute renal failure, and patients developing multiple organ failure. Regression modeling identified body mass index class as being independently associated with adverse outcomes and increased morbidity but an inverse relationship with mortality in patients who suffered severe blunt traumatic injury. Initial leukocyte genomic expression patterns between 163 patients in the four different body mass index groupings did not differ; however, analysis of gene differences between body mass index classes occurring over time demonstrated significant changes in 513 probe sets with significant pathway differences being related to cellular metabolism. Conclusions:Increasing body mass index is associated with increased morbidity following severe blunt trauma. The initial blood leukocyte inflammatory response to blunt trauma does not appear to differ significantly between patients despite increasing body mass index. Resolution of the inflammatory response may differ between patients on the basis of body mass index; however, additional work is needed to clarify the potential causality of this finding.

Multicenter review of diaphragm pacing in spinal cord injury: Successful not only in weaning from ventilators but also in bridging to independent respiration

BACKGROUND Ventilator-dependent spinal cord–injured (SCI) patients require significant resources related to ventilator dependence. Diaphragm pacing (DP) has been shown to successfully replace mechanical ventilators for chronic ventilator-dependent tetraplegics. Early use of DP following SCI has not been described. Here, we report our multicenter review experience with the use of DP in the initial hospitalization after SCI. METHODS Under institutional review board approval for humanitarian use device, we retrospectively reviewed our multicenter nonrandomized interventional protocol of laparoscopic diaphragm motor point mapping with electrode implantation and subsequent diaphragm conditioning and ventilator weaning. RESULTS Twenty-nine patients with an average age of 31 years (range, 17–65 years) with only two females were identified. Mechanism of injury included motor vehicle collision (7), diving (6), gunshot wounds (4), falls (4), athletic injuries (3), bicycle collision (2), heavy object falling on spine (2), and motorcycle collision (1). Elapsed time from injury to surgery was 40 days (range, 3–112 days). Seven (24%) of the 29 patients who were evaluated for the DP placement had nonstimulatable diaphragms from either phrenic nerve damage or infarction of the involved phrenic motor neurons and were not implanted. Of the stimulatable patients undergoing DP, 72% (16 of 22) were completely free of ventilator support in an average of 10.2 days. For the remaining six DP patients, two had delayed weans of 180 days, three had partial weans using DP at times during the day, and one patient successfully implanted went to a long-term acute care hospital and subsequently had life-prolonging measures withdrawn. Eight patients (36%) had complete recovery of respiration, and DP wires were removed. CONCLUSION Early laparoscopic diaphragm mapping and DP implantation can successfully wean traumatic cervical SCI patients from ventilator support. Early laparoscopic mapping is also diagnostic in that a nonstimulatable diaphragm is a convincing evidence of an inability to wean from ventilator support, and long-term ventilator management can be immediately instituted. LEVEL OF EVIDENCE Therapeutic study, level V.

Elderly injury: a profile of trauma experience in the Sunshine (Retirement) State

OBJECTIVE By using mandatory discharge data from a state agency, the records of 116,687 patients hospitalized for treatment of injury were evaluated to develop an epidemiologic and demographic profile of this population and to compare outcomes of patients treated in state-designated trauma centers (TC) with those treated in nontrauma centers (NTC). METHODS Injury severity was calculated by using the International Classification Injury Severity Score methodology to compute individual diagnosis survival risk ratios from 698,187 reported diagnoses, and then by using these survival risk ratios to determine probability of survival for every patient. The population was then categorized by age, injury type, treatment facility designation, injury severity as indicated by probability of survival, and discharge disposition. Incidence of potentially preventable death was compared between TC and NTC, as was the effect on outcome of noninjury comorbidity. RESULTS The average age of this population was 58 +/- 26 years with significant skew toward the elderly in NTC (mean age, 62 +/- 26 years). The most commonly encountered injuries likewise reflected the elderly nature of this population. Although 71.3% received care in NTC, the majority of severely injured were treated in TC. Potentially preventable mortality (>0.5) was significantly lower in TC. The effect of noninjury comorbidity on outcome was better managed by TC, both in terms of decreased mortality and in proportion of patients discharged home. CONCLUSION These data demonstrate the unique characteristics of injury victims treated in the state of Florida and indicate that the developing trauma system is demonstrating productivity in terms of avoidance of preventable death, efficient management of noninjury comorbid problems, and more complete recovery as indicated by proportion of patients discharged to home.

Traditional resuscitative practices fail to resolve metabolic acidosis in morbidly obese patients after severe blunt trauma.

BACKGROUND Obesity is a risk factor for postinjury complications; in particular, obese patients develop multiple organ failure (MOF) at a greater rate than do normal weight counterparts. Evaluation of differences in resuscitative practices altered by body mass index (BMI) might provide an explanation for the increased risk of MOF seen in these high-risk patients. METHODS We used prospectively collected multicenter data to retrospectively compare patients grouped by BMI with regard to resuscitation volumes and traditional end points during the first 48 hours after injury. Marshall MOF score was used as the primary outcome measure. RESULTS One thousand sixty-six patients were analyzed, with 877 meeting inclusion and exclusion criteria. All patients received similar volumes of resuscitation per kilogram lean and ideal body weight. Morbidly obese patients attained greater central venous pressures but otherwise differed little in attainment of standard cardiovascular end points. Despite this, morbidly obese patients resolved base deficit more slowly and remained in metabolic acidosis for 48 hours postinjury. Morbidly obese patients with persistent metabolic acidosis developed MOF at a significantly greater rate than did normal weight patients with or without persistent metabolic acidosis. CONCLUSIONS Morbidly obese trauma patients show prolonged metabolic acidosis despite receiving similar volumes and attaining similar end points of resuscitation when compared with patients in other BMI groups. Inadequate resuscitation based on inaccurate end points and metabolic disturbances associated with increased BMI are likely responsible; identification of the etiology, sources, and consequences of this acidosis may provide further insight into the susceptibility of the morbidly obese patient to develop postinjury organ failure.

A pilot study on the randomization of inferior vena cava filter placement for venous thromboembolism prophylaxis in high-risk trauma patients.

BACKGROUND Placement of prophylactic inferior vena cava filters (pIVCFs) for the prevention of pulmonary embolism (PE) in high-risk trauma patients (HRTPs) are widely practiced despite the lack of Level I data supporting this use. We report the 2-year interim analysis of the Filters in Trauma pilot study. METHODS This is a single institution, prospective randomized controlled pilot feasibility study in a Level I trauma center. HRTPs were identified for pIVCF placement by the Eastern Association for the Surgery of Trauma guidelines. From November 2008 to November 2010, HRTPs were enrolled and randomized to either pIVCF or no pIVCF. All patients received pharmacologic prophylaxis when safe. Primary outcomes included feasibility objectives and secondary outcomes were incidence of PE, deep vein thrombosis (DVT), and death. RESULTS Thirty-four of 38 enrolled patients were eligible for analysis. The baseline sociodemographic characteristics were balanced between the both groups. Results of the feasibility objectives included: time from admission to enrollment (mean, 47.4 hours ± 22.0 hours), time from enrollment to randomization (mean, 4.8 hours ± 9.1 hours), time from randomization to IVCF placement (mean, 16.9 hours ± 9.2 hours), adherence to weekly compression ultrasound within first month (IVCF group = 44.4%; non-IVCF group = 62.5%), and 1-month clinical follow-up (IVCF group = 83.3%; non-IVCF group = 100%). At 6-month follow-up, one PE in the nonfilter group and one DVT in the filter group had occurred. One non-PE-related death occurred in the filter group. Barriers to enrollment included inability to obtain informed consent due to patient refusal or no next of kin identified and delayed notification of eligibility status. CONCLUSION Our pilot study demonstrates for the first time that a randomized controlled trial evaluating the efficacy of pIVCFs in trauma patients is feasible. This pilot data will be used to inform the design of a multicenter randomized controlled trial to determine the incidence of PE and DVT in HRTPs receiving pIVCFs versus no pIVCF.

Comparison of carbon dioxide and iodinated contrast for cavography prior to inferior vena cava filter placement

BACKGROUND The use of iodinated contrast in the critically ill trauma patient has been associated with the development of acute renal failure. The low incidence of nephrotoxicity associated with carbon dioxide (CO(2)) makes it an ideal contrast agent for cavography. However, the use of CO(2) has been limited, because reportedly it underestimates the diameter of the inferior vena cava (IVC). METHODS During a 6-month period (January 2000 through June 2000), 25 adult trauma patients required IVC filter placement. Bedside cavagrams using CO(2) followed by iodinated contrast were employed to determine the diameter of the IVC and the anatomy of the renal veins. RESULTS Using CO(2) injection for cavography, we were able to determine the diameter of the IVC and the anatomy of the renal veins in all patients. Furthermore, when CO(2) cavography was compared with the results obtained with iodinated contrast, the difference in diameter of the IVC was within 1 mm. CONCLUSIONS Based on these data, it was determined that CO(2) cavagrams accurately reflect the diameter of the IVC and the anatomy of the renal veins. Additionally, CO(2) cavagrams can be safely performed in the intensive care unit during bedside placement of IVC filters.

Endovascular Treatment of Traumatic Thoracic Aortic Injuries

BACKGROUND Although a large proportion of patients with traumatic thoracic aortic injury die before undergoing definitive repair, those who survive still face ongoing risk of death and morbidity. Endovascular therapy may offer a minimally invasive alternative in the repair of the aortic injury. STUDY DESIGN We reviewed our experience with endovascular repair of traumatic aortic injuries using medical records, imaging studies, and a prospectively maintained endovascular and institutional trauma database. RESULTS Twenty-two patients underwent thoracic endovascular repair (TEVAR) of traumatic aortic injuries over 44 months. The mean (SD) age was 34+/-12 years and 68% were men. Among the 16 patients registered with our trauma database, the mean Injury Severity Score was 33+/-16 (range, 13 to 45). All injuries were sustained from blunt trauma; 95% of patients had nonaortic thoracic injuries, and 64% and 55% had extremity and abdominal injuries, respectively. Intraoperatively, 91% were repaired under general anesthesia, the mean procedure time was 80+/-52 minutes, and mean blood loss was 219+/-72 mL. The mean fluoroscopy time was 13+/-5 minutes and contrast volume 98+/-23 mL. Twenty-one patients (95%) required coverage of the left subclavian artery to achieve an adequate proximal landing zone. There were no in-hospital or 30-day deaths. The median length of stay was 8 days (range, 1 to 62 days), and 11 (50%) patients were able to be discharged home (versus to another extended care facility). At a mean followup of 7.7 months (range, 0 to 40 months) there were 2 patients (9%) who required endograft-related reintervention at 1 and 6 months. One was an access-related complication, and the second was complete device collapse with acute aortic occlusion, resulting in the patients death. CONCLUSIONS Although patients who undergo endovascular repair of traumatic thoracic aortic transections typically have significant concomitant injuries, the procedure itself is well tolerated and can be performed rapidly with minimal blood loss and contrast administration. But close followup is necessary given the risk of late complications.