Serial Endoscopic Evaluation of Esophageal Disease in a Cancer Model: A Paradigm Shift for Esophageal Adenocarcinoma (EAC) Drug Discovery and Development.

A rat model of surgically induced reflux recapitulates the development and progression of human esophageal adenocarcinoma (EAC). In this study, reflux was induced in rats followed by postoperative endoscopy with biopsy, to diagnose and monitor disease progression. Overall, percentage agreement between visual endoscopy and gold standard histology was 95%, with disease-specific classification accuracies of 100% and 75% for Barrett's with dysplasia and EAC, respectively. Additionally, the percentage agreement for biopsy in tumors >4 mm was 75%. Thereby, establishing endoscopic evaluation as a reliable tool to assess disease progression and provide biopsies for downstream correlates in a de novo EAC model.

More fateful than fruitful? Intracranial pressure monitoring in elderly patients with traumatic brain injury is associated with worse outcomes.

BACKGROUND: In an expanding elderly population, traumatic brain injury (TBI) remains a significant cause of death and disability. Guidelines for management of TBI, according to the Brain Trauma Foundation (BTF), include intracranial pressure (ICP) monitoring. Whether ICP monitoring contributes to outcomes in the elderly patients with TBI has not been explored. METHODS: This is a retrospective study extracted from the National Trauma Database 2007-2008 research datasets. Patients were included if aged >55 y and they met BTF indications for ICP monitoring. Patients that had nonsurvivable injuries (any body region, abbreviated injury score = 6), were dead on arrival, had withdrawal of care, or length of stay <48 h were excluded. Outcomes were then stratified based on ICP monitoring. The primary outcomes were inhospital mortality and favorable discharge. Logistic regression was used to analyze the effect of ICP monitoring on outcomes. RESULTS: A total of 4437 patients were included with 11.2% having an ICP monitor placed. Patients requiring an ICP monitor were younger overall, more likely to present hypertensive, had higher injury severity, and more likely to require operative intervention. Median initial Glasgow coma scale (3) was similar between groups. Of those patients with ICP monitoring, overall mortality was significantly higher, and they were less likely to have favorable discharge status. Craniotomy itself was not associated with increased mortality (P = 0.450). CONCLUSIONS: Our findings suggest that the use of ICP monitoring according to BTF guidelines in elderly TBI patients does not provide outcomes superior to treatment without monitoring. The ideal group to benefit from ICP monitor placement remains to be elucidated.

Sticking our neck out: is magnetic resonance imaging needed to clear an obtunded patient's cervical spine?

BACKGROUND: Evaluating the cervical spine in the obtunded trauma patient is a subject fraught with controversy. Some authors assert that a negative computed tomography (CT) scan is sufficient. Others argue that CT alone misses occult unstable injuries, and magnetic resonance imaging (MRI) will alter treatment. This study examines the data in an urban, county trauma center to determine if a negative cervical spine CT scan is sufficient to clear the obtunded trauma patient. METHODS: Records of all consecutive patients admitted to a level 1 trauma center from January 2000 to December 2011 were retrospectively analyzed. Patients directly admitted to the intensive care unit with a Glasgow Coma Scale score ≤13, contemporaneous CT and MRI, and a negative CT reading were included. The results of the cervical spine MRI were analyzed. RESULTS: A total of 309 patients had both CT and MRI, 107 (35%) of whom had negative CTs. Mean time between CT and MRI was 16 d. Of those patients, seven (7%) had positive acute traumatic findings on MRI. Findings included ligamentous injury, subluxation, and fracture. However, only two of these patients required surgical intervention. None had unstable injuries. CONCLUSIONS: In the obtunded trauma patient with a negative cervical spine CT, obtaining an MRI does not appear to significantly alter management, and no unstable injuries were missed on CT scan. This should be taken into consideration given the current efforts at cost-containment in the health care system. It is one of the larger studies published to date.

Exploring trauma recidivism in an elderly cohort.

PURPOSE: As the population ages, trauma in the elderly is an increasingly recognized source of elderly morbidity. However, previous reviews on the topic provide only broad recommendations. The purpose of this study was to examine the elderly recidivist cohort at an urban trauma center for mechanisms of repeat injury. METHODS: The trauma registry at a major urban trauma center was queried to identify all patients aged 65 and older admitted from 1991-2010. Recidivist admissions were compared to nonrecidivist admissions. Demographics, mechanism of injury, injury location, length of stay, and mortality data were collected. Recidivists' mechanism of injury was compared with their initial mechanism of injury. Descriptive statistics, Student t-test, and a z-rank test of proportions were applied with significance set to P ≤ 0.05. RESULTS: Between 1991 and 2010, 6476 patients aged 65+ were admitted, of which 79 (1.22%) were recidivists. Of these, 64 patients were aged 65 and older for both admissions. Most often, recidivists were male (70% versus 60%) and injured in penetrating trauma (17% versus 7.5%, P = 0.045). Recidivists trended towards more frequent injuries in bicycle collisions (3% versus 1.9%) and all-terrain vehicle (ATV)/motorcycle crashes (6.3% versus 1.7%), but were less likely to be hit by cars (49% versus 36%, P = 0.034). At least two thirds of recidivist patients injured in falls, ATV/motorcycle accidents, and stabbings had previously been injured by the same mechanism. CONCLUSIONS: The overall recidivism rate in the elderly population is low. Nevertheless, recidivists were more susceptible to penetrating trauma, ATV/motorcycle collisions, and possibly bicycle accidents. These findings can help design counseling initiatives and injury prevention programs that target specific elderly trauma patients.

Systemic ubiquitin release after blunt trauma and burns: association with injury severity, posttraumatic complications, and survival.

BACKGROUND: Recent data suggest that ubiquitin (Ub) is systemically released after trauma, has pleiotropic effects on host defense mechanisms, and that Ub administration reduces fluid shifts into tissues during inflammation. Ub release after burns (B) has not been studied and its association with injury severity and outcome after blunt trauma (T) is unknown. Thus, we evaluated Ubs association with injury severity and outcomes after B and T. METHODS: Injury severity was assessed with the Injury Severity Score (ISS) in T and burn size (% total body surface area, %TBSA) in B. A total of 129 T (ISS: 26 +/- 13) and 55 B (46% +/- 18% TBSA) were observed for sepsis/multiple organ failure (MOF) and survival. In B, sequential organ failure assessment scores were documented daily. Fifty volunteers served as controls (C) Ub serum levels were measured on day 0 (admission), 1, 3, 5, and 7 by enzyme-linked immunosorbent assay. Data were analyzed using bivariate or partial correlation analyses, t test, and analysis of variance with Tukey post-hoc test for multiple comparisons (two-tailed p < 0.05). RESULTS: Ub was significantly elevated in patients. Peak levels (ng/mL) were detectable on day 0 (C: 118 +/- 76; T: 359 +/- 205; B: 573 +/- 331) and increased with increased ISS, %TBSA, and presence of inhalation injury. In T, Ub normalized by day 3, but remained elevated in B. In B, Ub correlated significantly negative with sequential organ failure assessment scores (r: -0.143; p = 0.0147), sepsis/MOF development (r: -0.363; p = 0.001), and survival (r: -0.231; p = 0.009). Compared with B who recovered uneventfully, Ub levels were significantly lower on days 1 to 7 and on days 5/7 in B who developed sepsis/MOF or died, respectively. CONCLUSION: Ub concentrations reflect the extent of tissue damage. Along with Ubs previously described anti- inflammatory properties, this study suggests that its systemic release is protective, that burn patients who develop sepsis/MOF have a relative Ub deficiency and that Ub could play an important role during the physiologic response to burn injury.

How can trauma surgeons maintain their operative skills?

BACKGROUND: The operative experience of the dedicated trauma surgeon is declining. Much attention has focused on the operative workload of trauma surgeons as it is critical in both maintaining operative skills and promoting the interest of surgical residents in trauma careers. We examined the operative experience of our surgical service which includes trauma, emergency general surgery, and elective general surgery to analyze changes occurring over the past decade. METHODS: A retrospective study was performed by extracting data from the operative database at our Level I trauma center from January 1995 to December 2005. The cases were classified as trauma, emergency general surgery, or elective general surgery. Data were analyzed using weighted linear regression to analyze statistical significance. RESULTS: Although the total number of cases performed by the trauma service remained constant, the proportion of initial operative trauma cases (<24 hours from arrival to operation) decreased from 14% to 8% (r2 = 0.91, p < 0.001) over the study period. In contrast, emergency general surgery cases increased over this time period (r2 = 0.57, p < 0.01). Elective case volume was unchanged. The majority of the waning of trauma cases was due to decreased surgery on the liver and spleen and fewer neck explorations. CONCLUSIONS: Trauma operative experience decreased but emergency general surgery increased over a decade at our trauma center. It appears possible to maintain a busy operative trauma service by the inclusion of emergency general surgery consultations.

Aerosolized tobramycin in the treatment of ventilator-associated pneumonia: a pilot study.

OBJECTIVE: To evaluate the efficacy and safety of inhaled tobramycin (TOBI) in the treatment of ventilator-associated pneumonia (VAP) in a randomized, double-blind pilot study. PATIENTS AND METHODS: Ten patients from a cohort of 108 mechanically ventilated patients with documented clinical and bacteriological evidence of VAP caused by Pseudomonas aeruginosa or Acinetobacter spp. in the surgical and trauma intensive care units of a university teaching hospital were randomized to receive either TOBI (n = 5) or intravenous tobramycin (TOBRA; n = 5). The two groups were similar in their Acute Physiology and Chronic Health Evaluation (APACHE) score, Clinical Pulmonary Infection Score (CPIS), and Multiple Organ Dysfunction Score (MODS) prior to randomization. The primary outcome measure was resolution of pneumonia. The CPIS and MODS were used as objective indicators of clinical progress. RESULTS: All TOBI patients had clinical resolution of VAP. Two TOBRA patients were considered failures. One had deterioration in MODS, and the other had doubling of his serum creatinine concentration. The patients treated with TOBI may have had more ventilator-free days than those receiving TOBRA, but the difference was not statistically significant owing to the small sample size (24 +/- 3 vs. 14 +/- 13 days; p = 0.12). CONCLUSION: Aerosolized tobramycin for the treatment of VAP appeared safe and effective in this pilot study. A larger study is warranted to determine if aerosolized tobramycin will lead to better outcomes than intravenous tobramycin when used for the treatment of VAP.

The G60 Trauma Center: A Future Consideration?

With a considerably increasing elderly population, we sought to determine whether the volume of elderly trauma patients treated impacted outcomes at two different Level I trauma centers. This is a retrospective review of all elderly patients (>60 years) at two state-verified Level I trauma centers over the past five years. The elderly trauma center (ETC) saw a greater proportion (52%) of elderly patients than the reference trauma center (30%, TC). Demographic and clinical characteristics were abstracted and stratified into ETC and TC groups for comparison. Primary outcomes were overall postinjury complication and mortality rates, as well as death after major complication (failure to rescue). ETC patients were older (78.6 vs 70.5), more likely to be admitted with severe head injuries (head abbreviated injury score ≥ 3, 50.0% vs 32%), had a greater overall injury burden (injury severity score > 16 41.4% vs 21.1%), and required intensive care unit admission (81.3% vs 64%) than the TC group. Need for operative intervention, mechanism of injury, and comorbidities were similar between the two groups. Overall complications were higher in trauma patients admitted to the TC (21.9% vs 14.3%), as well as failure to rescue (4.0% vs 1.8%). Adjusting for confounding factors, ETC had significantly lower chance of developing a postinjury complication (adjusted odds ratios [AOR] = 0.4, 95% confidence interval [CI] = [0.3, 0.5]), failure to rescue (AOR = 0.3, 95% CI = [0.1, 0.5]), and overall mortality (AOR = 0.3, 95% CI = [0.2, 0.4]). Improved outcomes were demonstrated in the Level I center treating a higher proportion of elderly patients. Exact etiology of these benefits should be determined for quality improvement in care of the injured geriatric patient.

Magnetic resonance cholangiopancreatography accurately detects common bile duct stones in resolving gallstone pancreatitis.

BACKGROUND: There is controversy about the optimal method to detect common bile duct (CBD) stones in patients with mild resolving gallstone pancreatitis. The aim of this study was to evaluate magnetic resonance cholangiopancreatography (MRCP) in detecting choledocholithiasis in this group of patients. STUDY DESIGN: A prospective randomized trial was conducted. Patients randomized to group 1 (n = 34) underwent laparoscopic cholecystectomy (LC) and intraoperative cholangiography (IOC). Those randomized to group 2 (n = 29) had preoperative MRCP, of these, patients with negative MRCP underwent LC and IOC, patients with positive MRCP had preoperative ERCP followed by LC. RESULTS: Sixty-three patients were randomized (34 to group 1 and 29 to group 2). CBD stones were found in 5 patients in group 1. CBD exploration was performed in 2 patients, preoperative ERCP in 1, and postoperative ERCP in the other 2. MRCP showed CBD stones in 4 patients in group 2. There were two false-positive MRCPs. Four patients with a negative MRCP did not have IOC or ERCP, the remaining 21 patients with a negative MRCP had a negative IOC. The MRCP sensitivity was 100% (95% CI, 16-100%), specificity 91% (95% CI, 72-99%), positive predictive value 50% (95% CI, 7-93%), negative predictive value 100% (95% CI, 84-100%), and accuracy 92% (95% CI, 74-99%). CONCLUSIONS: Patients with resolving gallstone pancreatitis and a negative MRCP do not need preoperative ERCP or IOC. Only patients with a positive MRCP will require preoperative ERCP.

Recent trends in the management of combined pancreatoduodenal injuries.

In an effort to better characterize the natural history of pancreatoduodenal injuries, we present a review of clinical experiences in the treatment of combined traumatic pancreatoduodenal injuries, focusing on patients in extremis. Records of patients with abdominal trauma admitted to a level 1 trauma center from 1997 to 2001 were reviewed. Of 240 patients who sustained a pancreatic or duodenal injury, 33 had combined pancreatoduodenal injuries. Eighty-two per cent of the patients (27/33) in this series had penetrating injuries, 72 per cent (24) sustained gunshot wounds (GSW). Thirty-one patients were male, and the mean age was 33 years (range, 7-74). These patients presented with an average Injury Severity Score (ISS) of 22 +/- 12 and an average Glasgow Coma Score of 14 +/- 2. Overall length of stay was 39 +/- 59 days (range, 0-351 days). These 33 patients underwent a total of 57 laparotomies with an average of 1.7 operations per patient (range, 1 to 5 operations). Eighty-four per cent of the patients had an associated gastrointestinal injury and 45 per cent had a major vascular injury. Thirteen of the 33 (39%) patients presented in extremis, all 13 underwent an abbreviated laparotomy. The complication rate was 36 per cent, including fistula, abscess, pancreatitis, and organ dysfunction. There were 6 hospital deaths for a mortality rate of 18 per cent. Pancreatoduodenal injuries are associated with a variety of other serious injuries, which add to the overall complexity of these patients. Abbreviated laparotomy may be helpful when managing combined pancreatoduodenal injuries in patients who are in extremis.

Portal vein thrombosis: an unusual complication of laparoscopic cholecystectomy.

BACKGROUND: Complications following laparoscopic cholecystectomy are encountered infrequently due to increasing proficiency in laparoscopic surgery. The occurrence of portal venous thrombosis following laparoscopic cholecystectomy has not been previously described and forms the basis of this report. METHODS: A healthy, 32-year-old, female on oral contraceptives underwent an uneventful laparoscopic cholecystectomy for symptomatic gallbladder disease. Sequential compression devices and mini-dose unfractionated heparin were used before the procedure. The patient was discharged home on the first postoperative day without complaints. She returned 1 week later with nausea, bloating, and diffuse abdominal pain. RESULTS: Ultrasonography of the abdomen revealed thrombosis of the portal vein not seen in the preoperative ultrasound and the superior mesenteric vein. Computer tomography of the abdomen and pelvis on the same day confirmed this finding and showed a wedge-shaped infarction of the right lobe of the liver. The patient was anticoagulated with intravenous heparin. An extensive coagulation workup revealed elevation of the Immunoglobulin G anticardiolipin antibody. A percutaneous transhepatic portal vein thrombectomy was performed. A postprocedure duplex ultrasound of the abdomen demonstrated recannalization of the portal venous system with no flow voids. Anticoagulation therapy was continued, and the patient was discharged home with resolution of her ileus. She was maintained on a therapeutic dose of warfarin. CONCLUSIONS: This case demonstrates an unusual complication of laparoscopic cholecystectomy. It may have resulted from the use of oral contraceptives, elevation of the Immunoglobulin G anticardiolipin antibody, unrecognized trauma, and was accentuated by the pneumoperitoneum generated for the performance of the laparoscopic cholecystectomy. Our case report provides insight and poses questions regarding necessary perioperative measures for thromboprophylaxis in young females on oral contraceptives undergoing elective laparoscopic abdominal surgery.

Does unit designation matter? A dedicated trauma intensive care unit is associated with lower postinjury complication rates and death after major complication.

BACKGROUND: Recent data suggest that specialty intensive care units (ICUs) have outcomes better than those of mixed ICUs. The cause for this apparent discrepancy has not been well established. We hypothesized that trauma patients admitted to a dedicated trauma ICU (TICU) would have a lower complication rate as well as death after complication (failure to rescue [FTR]). METHODS: This was a retrospective review of the ICUs of two Level I trauma centers covered by one group of surgical intensivists. One center has a dedicated TICU, while the other has a mixed ICU. Demographic and clinical characteristics were stratified into TICU and ICU groups. The primary outcomes were postinjury complications and FTR. Multivariate regression was used to derive factors associated with complications and FTR. RESULTS: During the 5-year study period, 3,833 patients were analyzed. TICU patients were older (57.8 vs. 47.0 years, p < 0.0001), had higher Charlson score (2 vs. 1, p = 0.001), had more severe head injuries (Head Abbreviated Injury Scale [AIS] score ≥ 3, 50.0% vs. 37.5%, p < 0.0001), and had greater injury burden (Injury Severity Score [ISS] > 16, 49.6% vs. 38.6%, p < 0.0001) than those admitted to the mixed ICU. Need for immediate operative intervention was similar (18.0% vs. 17.6%, p = 0.788). Overall complications were significantly higher in trauma patients admitted to the mixed ICU (27.5% vs. 17.0%, p < 0.0001), as well as FTR (3.7% vs. 1.8%, p < 0.0001). Trauma patients admitted to a dedicated TICU had significantly lower chance of developing a postinjury complication (adjusted odds ratio [AOR], 0.5; p < 0.0001), FTR (AOR, 0.3; p < 0.0001), and overall mortality (AOR, 0.4; p < 0.0001). CONCLUSION: Admission of critically ill trauma patients to a TICU staffed by a surgical intensivist is associated with a lower complication rate and FTR. Factors such as trauma nursing experience, education, and unit management structure should be further explored to elucidate the observed improved outcomes. LEVEL OF EVIDENCE: Prognostic study, level III.

Surgeon-performed ultrasound in the ICU setting.

Evaluation of critically ill patients is often challenging due to altered sensorium, underlying disease, and the presence of multiple drains or monitoring devices. In such circumstances, the ability of physicians to perform ultrasound examinations in the intensive care unit provides a useful diagnostic and therapeutic adjunct. In this article,we review the application of surgeon-performed ultrasonography in the evaluation and management of critically ill patients.

Probable cause in helicopter emergency medical services crashes: what role does ownership play?

BACKGROUND: The National Transportation Safety Board (NTSB) ranks helicopter emergency medical services (HEMS) as one of the most perilous occupations in the United States, with improvements in its safety of highest priority. As many injured patients are transported by helicopter, this is of particular concern to the trauma community. The use of HEMS is associated with a heightened degree of inherent risk. We hypothesized that this risk is not uniform and varies with the entity providing HEMS, specifically, commercial versus public safety providers. METHODS: The NTSB accident database was queried to identify all HEMS-involved events for the 15-year period 1998 to 2012. The NTSB investigation report was reviewed to obtain crash details including probable cause. These were analyzed on the basis of HEMS ownership. Statistical analyses were performed using analysis of variance and Fisher's exact test as appropriate. RESULTS: During the study period, 139 (6.8%) of 2,040 crashes involved HEMS and occurred across 134 cities in 37 states, killing 120 and seriously injuring 146. Of these, 118 involved commercial, 14 not-for-profit, and 7 public safety HEMS. Analyzed in 5-year blocks, no decrease in crash incidence was seen (p = 0.7, analysis of variance). Human and pilot errors were significantly more common among commercial HEMS compared with public safety HEMS (91 of 118 vs. 2 of 7, p = 0.013, and 75 of 116 vs. 1 of 7, p = 0.017, Fisher's exact test). Conditions for which training was not adequate, limited resources, inadequate equipment, and the undertaking of suboptimal trips were identified as key factors. Trauma patients were involved in 34 transports (24.5%), with a fatal or serious outcome in 68 crew/patients on 12 flights. CONCLUSION: Potentially preventable human and pilot error-related HEMS crashes are significantly more frequent among commercial compared with public safety providers. Deficiencies in training, reduced availability of equipment and resources, as well as questionable flight selection seem to play a key role. LEVEL OF EVIDENCE: Epidemiologic study, level III.

Incidence and crash mechanisms of aortic injury during the past decade.

BACKGROUND: Aortic injuries were traditionally thought to be the result of severe frontal crashes. Newer data has suggested other crash types such as nearside crashes may also be important in aortic injury. We hypothesized the implementation of recent safety measures would decrease the incidence of aortic injury associated with fatal motor vehicle crashes. METHODS: The autopsy reports of all traffic fatalities for motor vehicle occupants in a large urban county for the years 1993 to 2004 were examined. The demographics, impact types, safety measures used, and the presence of any aortic injury were recorded. Trends were evaluated for significance by weighted linear regression. RESULTS: The incidence of aortic injury associated with fatal motor vehicle crashes has remained unchanged during the past 12 years (r = 0.057, p = 0.45). There is a trend toward decreased aortic injuries associated with frontal crashes (r = 0.26, p = 0.089) but no change in aortic injuries associated with nearside or farside crashes (r = 0.053, p = 0.47), when the crash resulted in a fatality. This is despite an increase in seat belt use and increased presence of airbags during the same time period. CONCLUSIONS: Despite improved safety measures designed to minimize the occurrence of aortic injuries, the incidence of blunt aortic injury in fatal motor vehicle crashes has not decreased during the past decade. Although not statistically significant, there is a trend toward decreased frontal impacts in fatal motor vehicle crashes associated with aortic injuries. The nearside crash mechanism continues to play a prominent role, and efforts at improving vehicle safety should be focused on crash mechanisms as they relate to aortic injury.

Cystogram follow-up in the management of traumatic bladder disruption.

BACKGROUND: The utility of obtaining a routine cystogram after the repair of intraperitoneal bladder disruption before urethral catheter removal is unknown. This study was designed to examine whether follow-up cystogram evaluation after traumatic bladder disruption affected the clinical management of these injuries. We hypothesized that routine cystograms, after operative repair of intraperitoneal bladder disruptions, provide no clinically useful information and may be eliminated in the management of these injuries. METHODS: Our prospectively collected trauma database was retrospectively reviewed for all ICD-9 867.0 and 867.1 coded bladder injuries over a 6-year period ending in June 2004. Demographics, clinical injury data, detailed operative records, and imaging studies were reviewed for each patient. Bladder injuries were categorized as intraperitoneal (IP) or extraperitoneal (EP) bladder disruptions based on imaging results and operative exploration. Patients with IP injuries were further subdivided into those with "simple" dome disruptions or through-and-through penetrating injuries and "complex" injuries involving the trigone or ureter reimplantation. All patients sustaining isolated ureteric or urethral injury were excluded from further analysis. RESULTS: In all, 20,647 trauma patients were screened for bladder injury. Out of this group, there were 50 IP (47 simple, 3 complex) and 37 EP injuries available for analysis. All IP injuries underwent operative repair. Eight of the IP injuries (all simple) had no postoperative cystogram and all were doing well at 1- to 4-week follow-up. The remaining 42 patients underwent a postoperative cystogram at 15.3 +/- 7.3 days (range 7 to 36 days). All simple IP injuries had a negative postoperative cystogram. The only positive study was in one of the three complex IP injuries. In the EP group, 21.6% had positive cystograms requiring further follow-up and intervention. CONCLUSIONS: Patients sustaining extraperitoneal and complex intraperitoneal bladder disruptions require routine cystogram follow-up. In those patients undergoing repair of a simple intraperitoneal bladder disruption, however, routine follow-up cystograms did not affect clinical management. Further prospective evaluation to determine the optimal timing of catheter removal in this patient population is warranted.

How long should you wait for a chest radiograph after placing a chest tube on water seal? A prospective study.

OBJECTIVE: The purpose of this study was to determine the optimal time interval for identifying a pneumothorax (PTX) on chest radiograph (CXR) after placing a chest tube on water seal. METHODS: One hundred nineteen chest tubes were placed on water seal according to a prospective, observational study protocol. After water seal, both an early (3.1 +/- 2.1 hours) and a late (17.6 +/- 8.0 hours) CXR was obtained. RESULTS: Thirty-one patients had a PTX on follow-up CXRs. There were 22 early and 9 late PTXs identified. Three patients in the early group had a clinically significant PTX or an increase in the size of PTX on follow-up CXR. None of the patients in the late group had a clinically significant PTX (any worsening of their PTX) or required further intervention. CONCLUSION: A normal chest radiograph obtained 3 hours after placing a chest tube on water seal effectively excludes development of a clinically significant pneumothorax.

Can near-infrared spectroscopy identify the severity of shock in trauma patients?

BACKGROUND: Our recent experimental study showed that peripheral muscle tissue oxygen saturation (StO2), determined noninvasively by near-infrared spectroscopy (NIRS), was more reliable than systemic hemodynamics or invasive oxygenation variables as an index of traumatic shock. The purpose of this study was to establish the normal range of thenar muscle StO2 in humans and the relationship between shock state and StO2 in trauma patients. METHODS: This was a prospective, nonrandomized, observational, descriptive study in normal human volunteers (n = 707) and patients admitted to the resuscitation area of our Level I trauma center (n = 150). To establish a normal StO2 range, an NIRS probe was applied to the thenar eminence of volunteers (normals). Subsequently, in a group of trauma patients, an NIRS probe was applied to the thenar eminence and data were collected and stored for offline analysis. StO2 monitoring was performed continuously and noninvasively, and values were recorded at 2-minute intervals. Five moribund trauma patients were excluded. Members of our trauma faculty, blinded to StO2 values, classified each patient into one of four groups (no shock, mild shock, moderate shock, and severe shock) using conventional physiologic parameters. RESULTS: Mean +/- SD thenar StO2 values for each group were as follows: normals, 87 +/- 6% (n = 707); no shock, 83 +/- 10% (n = 85); mild shock, 83 +/- 10% (n = 19); moderate shock, 80 +/- 12% (n = 14); and severe shock, 45 +/- 26% (n = 14). The thenar StO2 values clearly discriminated the normals or no shock patients and the patients with severe shock (p < 0.05). CONCLUSION: Decreased thenar muscle tissue oxygen saturation reflects the presence of severe hypoperfusion and near-infrared spectroscopy may be a novel method for rapidly and noninvasively assessing changes in tissue dysoxia.

Blood substitutes.

PURPOSE OF REVIEW: Risk of disease transmission and limitations in the ability to transfuse in the prehospital or combat setting have stimulated research in the field of oxygen therapeutics. Several products have completed safety trials and are presently undergoing investigation for their efficacy. In the near future, the clinician will likely employ these products in the management of a variety of patient populations. Though similar in their oxygen carrying capacity, each agent possesses distinct physiologic effects. Understanding of the benefits and shortcomings of the various compounds is essential in order to optimally utilize them in various clinical settings. This review provides an overview of recent developments in the field of oxygen therapeutics and highlights results of clinical trials. RECENT FINDINGS: Modified hemoglobin solutions of human or bovine origin and perfluorochemical-based emulsions are in advanced stages of clinical testing. Bovine hemoglobin-based solutions have been associated with vascular reactivity, methemoglobin formation and development of antibodies. Larger safety trials are necessary before they can find widespread use. Polymerized human hemoglobin solutions have a favorable safety profile in early trials and have been effective as a resuscitation fluid in circumstances when red cells may be unavailable. Unfortunately, outdated human blood, the substrate for this product, is itself in short supply. Perfluorocarbons similarly reduce the need for allogeneic transfusion, but the need for high-inspired oxygen levels currently limits use. Recombinant, polymer-encapsulated and additional forms of chemically modified hemoglobins are being developed and are undergoing testing in animal models SUMMARY: Oxygen carriers offer a viable alternative to allogeneic transfusion. All oxygen therapeutic agents are not clinically equivalent. Optimal utilization requires a thorough understanding of the therapeutic potentials and adverse effects of the solution being considered for use.