Proactive Versus Reactive Control Strategies Differentially Mediate Alcohol Drinking in Male Wistars and P Rats.

Problematic alcohol consumption is associated with deficits in decision-making and alterations in prefrontal cortex neural activity likely contribute. We hypothesized that the differences in cognitive control would be evident between male Wistars and a model of genetic risk: alcohol-preferring P rats. Cognitive control is split into proactive and reactive components. Proactive control maintains goal-directed behavior independent of a stimulus, whereas reactive control elicits goal-directed behavior at the time of a stimulus. We hypothesized that Wistars would show proactive control over alcohol seeking whereas P rats would show reactive control over alcohol seeking. Neural activity was recorded from the prefrontal cortex during an alcohol seeking task with two session types. On congruent sessions, the conditioned stimulus (CS+) was on the same side as alcohol access. Incongruent sessions presented alcohol opposite the CS+. Wistars, but not P rats, made more incorrect approaches during incongruent sessions, suggesting that Wistars utilized the previously learned rule. This motivated the hypothesis that neural activity reflecting proactive control would be observable in Wistars but not P rats. While P rats showed differences in neural activity at times of alcohol access, Wistars showed differences prior to approaching the sipper. These results support our hypothesis that Wistars are more likely to engage in proactive cognitive control strategies whereas P rats are more likely to engage in reactive cognitive control strategies. Although P rats were bred to prefer alcohol, the differences in cognitive control may reflect a sequela of behaviors that mirror those in humans at risk for an AUD.

Proactive Versus Reactive Control Strategies Differentially Mediate Alcohol Drinking in Wistar and P rats.

Problematic alcohol consumption is associated with deficits in decision-making, and alterations in prefrontal cortex neural activity likely contributes. We hypothesized that differences in cognitive control would be evident between male Wistar rats and a model for genetic risk for alcohol use disorder (alcohol-preferring P rats). Cognitive control can be split into proactive and reactive components. Proactive control maintains goal-directed behavior independent of a stimulus whereas reactive control elicits goal-directed behavior at the time of a stimulus. We hypothesized that Wistars would show proactive control over alcohol-seeking whereas P rats would show reactive control over alcohol-seeking. Neural ensembles were recorded from prefrontal cortex during an alcohol seeking task that utilized two session types. On congruent sessions the CS+ was on the same side as alcohol access. Incongruent sessions presented alcohol opposite the CS+. Wistars, but not P rats, exhibited an increase in incorrect approaches during incongruent sessions, suggesting that Wistars utilized the previously learned task-rule. This motivated the hypothesis that ensemble activity reflecting proactive control would be observable in Wistars but not P rats. While P rats showed differences in neural activity at times relevant for alcohol delivery, Wistars showed differences prior to approaching the sipper. These results support our hypothesis that Wistars are more likely to engage proactive cognitive-control strategies whereas P rats are more likely to engage reactive cognitive control strategies. Although P rats were bred to prefer alcohol, differences in cognitive control may reflect a sequela of behaviors that mirror those in humans at risk for an AUD.

Inhibition of IkappaB kinase alpha (IKKα) or IKKbeta (IKKß) plus forkhead box O (Foxo) abolishes skeletal muscle atrophy.

Two transcription factor families that are activated during multiple conditions of skeletal muscle wasting are nuclear factor κB (NF-κB) and forkhead box O (Foxo). There is clear evidence that both NF-κB and Foxo activation are sufficient to cause muscle fiber atrophy and they are individually required for at least half of the fiber atrophy during muscle disuse, but there is no work determining the combined effect of inhibiting these factors during a physiological condition of muscle atrophy. Here, we determined whether inhibition of Foxo activation plus inhibition of NF-κB activation, the latter by blocking the upstream inhibitor of kappaB kinases (IKKα and IKKß), would prevent muscle atrophy induced by 7 days of cast immobilization. Results were based on measurements of mean fiber cross-sectional area (CSA) from 72 muscles transfected with 5 different mutant expression plasmids or plasmid combinations. Immobilization caused a 47% decrease in fiber CSA in muscles injected with control plasmids. Fibers from immobilized muscles transfected with dominant negative (d.n.) IKKα-EGFP, d.n. IKKß-EGFP or d.n. Foxo-DsRed showed a 22%, 57%, and 76% inhibition of atrophy, respectively. Co-expression of d.n. IKKα-EGFP and d.n. Foxo-DsRed significantly inhibited 89% of the immobilization-induced fiber atrophy. Similarly, co-expression of d.n. IKKß-EGFP and d.n. Foxo-DsRed inhibited the immobilization-induced fiber atrophy by 95%. These findings demonstrate that the combined effects of inhibiting immobilization-induced NF-κB and Foxo transcriptional activity has an additive effect on preventing immobilization-induced atrophy, indicating that NF-κB and Foxo have a cumulative effect on atrophy signaling and/or atrophy gene expression.

Validating the Injury Severity Score (ISS) in different populations: ISS predicts mortality better among Hispanics and females.

INTRODUCTION: The Injury Severity Score (ISS) is the most commonly used measure of injury severity. The score has been shown to have excellent predictive capability for trauma mortality and has been validated in multiple data sets. However, the score has never been tested to see if its discriminatory ability is affected by differences in race and gender. OBJECTIVE: This study is aimed at validating the ISS in men and women and in three different race/ethnic groups using a nationwide database. METHODS: Retrospective analysis of patients age 18-64 y in the National Trauma Data Bank 7.0 with blunt trauma was performed. ISS was categorized as mild (<9,) moderate (9-15), severe (16-25), and profound (>25). Logistic regression was done to measure the relative odds of mortality associated with a change in ISS categories. The discriminatory ability was compared using the receiver operating characteristics curves (ROC). A P value testing the equality of the ROC curves was calculated. Age stratified analyses were also conducted. RESULTS: A total of 872,102 patients had complete data for the analysis on ethnicity, while 763,549 patients were included in the gender analysis. The overall mortality rate was 3.7%. ROC in Whites was 0.8617, in Blacks 0.8586, and in Hispanics 0.8869. Hispanics have a statistically significant higher ROC (P value < 0.001). Similar results were observed within each age category. ROC curves were also significantly higher in females than in males. CONCLUSION: The ISS possesses excellent discriminatory ability in all populations as indicated by the high ROCs.

Healing of traumatic diaphragm injuries: comparison of laparoscopic versus open techniques in an animal model.

BACKGROUND: Minimally invasive surgical techniques have become routinely applied to the evaluation and treatment of patients with isolated diaphragmatic injuries due to penetrating trauma. The objective of the study was to compare the healing of diaphragm injuries as determined by macroscopic inspection, histologic appearance, and tensile strength following repair by open suturing, laparoscopic suturing, and laparoscopic stapling techniques in an animal model. METHODS: Using a pig model, three injuries were created and repaired in each hemidiaphragm of five animals, for a total of 30 lacerations. These injuries were repaired using single-layer open repair, single-layer laparoscopic repair, or laparoscopic stapling. After a 6-week healing period the animals were sacrificed. The gross integrity, histologic appearance using H+E and trichrome satins, and tensile strength of each repair were assessed. RESULTS: All injuries were grossly intact without dehiscence or herniation. Histologic examination revealed no difference in the collagen deposition between the three groups. The tensile strengths of each type of repair were similar. CONCLUSION: Laparoscopic techniques used to repair diaphragmatic injuries allow for adequate healing equivalent to open sutured repairs. Simple approximation of the peritoneum with laparoscopic staples allows full-thickness healing of these injuries.

Penetrating colon injuries requiring resection: diversion or primary anastomosis? An AAST prospective multicenter study.

BACKGROUND: The management of colon injuries that require resection is an unresolved issue because the existing practices are derived mainly from class III evidence. Because of the inability of any single trauma center to accumulate enough cases for meaningful statistical analysis, a multicenter prospective study was performed to compare primary anastomosis with diversion and identify the risk factors for colon-related abdominal complications. METHODS: This was a prospective study from 19 trauma centers and included patients with colon resection because of penetrating trauma, who survived at least 72 hours. Multivariate logistic regression analysis was used to compare outcomes in patients with primary anastomosis or diversion and identify independent risk factors for the development of abdominal complications. RESULTS: Two hundred ninety-seven patients fulfilled the criteria for inclusion and analysis. Overall, 197 patients (66.3%) were managed by primary anastomosis and 100 (33.7%) by diversion. The overall colon-related mortality was 1.3% (four deaths in the diversion group, no deaths in the primary anastomosis group, p = 0.012). Colon-related abdominal complications occurred in 24% of all patients (primary repair, 22%; diversion, 27%; p = 0.373). Multivariate analysis including all potential risk factors with p values < 0.2 identified three independent risk factors for abdominal complications: severe fecal contamination, transfusion of > or = 4 units of blood within the first 24 hours, and single-agent antibiotic prophylaxis. The type of colon management was not found to be a risk factor. Comparison of primary anastomosis with diversion using multivariate analysis adjusting for the above three identified risk factors or the risk factors previously described in the literature (shock at admission, delay > 6 hours to operating room, penetrating abdominal trauma index > 25, severe fecal contamination, and transfusion of > 6 units blood) showed no statistically significant difference in outcome. Similarly, multivariate analysis and comparison of the two methods of colon management in high-risk patients showed no difference in outcome. CONCLUSION: The surgical method of colon management after resection for penetrating trauma does not affect the incidence of abdominal complications, irrespective of associated risk factors. Severe fecal contamination, transfusion of > or = 4 units of blood within the first 24 hours, and single-agent antibiotic prophylaxis are independent risk factors for abdominal complications. In view of these findings, the reduced quality of life, and the need for a subsequent operation in colostomy patients, primary anastomosis should be considered in all such patients.

Thoracolumbar immobilization for trauma patients with torso gunshot wounds: is it necessary?

BACKGROUND: Previous studies have suggested that patients transported by emergency medical services (EMS) following major trauma had a longer injury-to-treatment interval and a higher mortality rate than their non-EMS-transported counterparts. HYPOTHESIS: There is little actual benefit of thoracolumbar immobilization for patients with torso gunshot wounds (GSW). DESIGN: Retrospective analysis of prospectively gathered data from the Maryland Institute for Emergency Medical Service Systems State Trauma Registry from July 1, 1995, through June 30, 1998. SETTINGS: All designated trauma centers in Maryland. PATIENTS: All patients with torso GSW. MAIN OUTCOME MEASURES: (1) A patient was considered to have benefited from immobilization if he or she had less than complete neurologic deficits in the presence of an unstable vertebral column, as shown by the need for operative stabilization of the vertebral column; (2) mortality. RESULTS: There were 1000 patients with torso GSW. Among them, 141 patients (14.1%) had vertebral column and/or spinal cord injuries. Two patients (0.2%) (95% confidence interval, -0.077% to 0.48%) required operative vertebral column stabilization, while 6 others required other spinal operations for decompression and/or foreign body removal. The presence of vertebral column injury was actually associated with lower mortality (7.1% vs 14.8%, P<.02). CONCLUSIONS: This study suggests that thoracolumbar immobilization is almost never beneficial in patients with torso GSW, and that a higher mortality rate existed among those GSW patients without vertebral column injury vs those with such injuries. The role of formal thoracolumbar immobilization for patients with torso GSW should be reexamined.

Sickness Impact Profile Score versus a Modified Short-Form survey for functional outcome assessment: acceptability, reliability, and validity in critically ill patients with prolonged intensive care unit stays.

BACKGROUND: Quality of life after surgical critical illness is an important measure of outcome. The Sickness Impact Profile Score (SIP) has been validated in critically ill patients, but the Modified Short-Form (MSF) has not been directly compared with it. METHODS: The SIP and MSF-36 were coadministered to 127 patients (surrogates) with a prolonged surgical critical illness at baseline at 1, 3, 6, and 12 months. Reliability, validity, and acceptability were determined for overall and subscores at each time point. RESULTS: The overall SIP and eight subscores, including physical health and psychosocial health, were all significantly improved at 1 year compared with baseline (p < 0.05). However, the MSF-36 was improved only in health perception (p < 0.05), but pain scores were higher (p < 0.05) than at baseline. Internal consistency of the MSF-36 was poor at 1 and 3 months. Correlation between the tools was excellent at baseline and 1 year but variable in overall and subscores at other time points. CONCLUSION: The SIP is more comprehensive, reliable, and acceptable in determining specific quality-of-life abnormalities, but the MSF-36 is easier to administer and correlates well at baseline and 1 year in patients with a prolonged critical illness.

Traumatic asphyxia complicated by unwitnessed cardiac arrest.

We report a case of traumatic asphyxia complicated by unwitnessed cardiac arrest in which the patient has made a good, functional recovery. Traumatic asphyxia is an uncommon clinical syndrome usually occurring after chest compression. Associated physical findings include subconjunctival hemorrhage and purple-blue neck and face discoloration. These facial changes can mimic those seen with massive closed head injury; however, cerebral injury after traumatic asphyxia usually occurs due to cerebral hypoxia. When such features are observed, the diagnosis of traumatic asphyxia should be considered. Prompt treatment with attention to the reestablishment of oxygenation and perfusion may result in good outcomes.

Endpoints of resuscitation of critically injured patients: normal or supranormal? A prospective randomized trial.

OBJECTIVE: To evaluate the effect of early optimization in the survival of severely injured patients. SUMMARY BACKGROUND DATA: It is unclear whether supranormal ("optimal") hemodynamic values should serve as endpoints of resuscitation or simply as markers of the physiologic reserve of critically injured patients. The failure of optimization to produce improved survival in some randomized controlled trials may be associated with delays in starting the attempt to reach optimal goals. There are limited controlled data on trauma patients. METHODS: Seventy-five consecutive severely injured patients with shock resulting from bleeding and without major intracranial or spinal cord trauma were randomized to resuscitation, starting immediately after admission, to either normal values of systolic blood pressure, urine output, base deficit, hemoglobin, and cardiac index (control group, 35 patients) or optimal values (cardiac index >4.5 L/min/m2, ratio of transcutaneous oxygen tension to fractional inspired oxygen >200, oxygen delivery index >600 mL/min/m2, and oxygen consumption index >170 mL/min/m2; optimal group, 40 patients). Initial cardiac output monitoring was done noninvasively by bioimpedance and, subsequently, invasively by thermodilution. Crystalloids, colloids, blood, inotropes, and vasopressors were used by predetermined algorithms. RESULTS: Optimal values were reached intentionally by 70% of the optimal patients and spontaneously by 40% of the control patients. There was no difference in rates of death (15% optimal vs. 11% control), organ failure, sepsis, or the length of intensive care unit or hospital stay between the two groups. Patients from both groups who achieved optimal values had better outcomes than patients who did not. The death rate was 0% among patients who achieved optimal values compared with 30% among patients who did not. Age younger than 40 years was the only independent predictive factor of the ability to reach optimal values. CONCLUSIONS: Severely injured patients who can achieve optimal hemodynamic values are more likely to survive than those who cannot, regardless of the resuscitation technique. In this study, attempts at early optimization did not improve the outcome of the examined subgroup of severely injured patients.

Emergency medical services (EMS) vs non-EMS transport of critically injured patients: a prospective evaluation.

BACKGROUND: A previous report of 5,782 trauma patients demonstrated higher mortality among those transported by emergency medical services (EMS) than among their non-EMS-transported counterparts. HYPOTHESIS: Trauma patients who are transported by EMS and those who are not differ in the injury-to-hospital arrival time interval. DESIGN: Prospective cohort-matched observation study. SETTING: Level I trauma center, multidisciplinary study group. PATIENTS: All non-EMS patients were matched with the next appropriate EMS patient by an investigator who was unaware of the outcome and mode of transport. Every 10th EMS patient with an Injury Severity Score (ISS) of 13 or greater was also randomly enrolled. Matching characteristics included age, ISS, mechanism of injury, head Abbreviated Injury Score, and presence of hypotension. An interview protocol was developed to determine the time of injury. Interview responses from patients, witnesses, and friends were combined with data obtained from police, sheriff, and medical examiner reports. MAIN OUTCOME MEASURES: Time to the hospital, mortality, morbidity, and length of stay. RESULTS: A total of 103 patients were enrolled (38 non-EMS, 38 EMS matched, 27 random EMS). Injury time was estimated using all available data made on 100 patients (97%). Independent raters agreed in 81% of cases. Deaths, complications, and length of hospital stay were similar between the EMS- and non-EMS-transported groups. Although time intervals were similar among the groups overall, more critically injured non-EMS patients (ISS > or = 13) got themselves to the trauma center in less time than their EMS counterparts (15 minutes vs 28 minutes; P<.05). CONCLUSIONS: A multidisciplinary approach can be utilized, and an interview protocol created to determine actual time of injury. Critically injured non-EMS-transported patients (ISS > or =13) arrived at the hospital earlier after their injuries.

Duration of antibiotic prophylaxis in high-risk patients with penetrating abdominal trauma: a prospective randomized trial.

To evaluate the effect of varying durations of antibiotic prophylaxis in trauma patients with multiple risk factors for postoperative septic complications, a prospective randomized trial was undertaken at an urban level I trauma center. The inclusion criteria were full-thickness colon injury and one of the following: (1) Penetrating Abdominal Trauma Index > 25, (2) transfusion of 6 units or more of packed red blood cells, or (3) more than 4 hours from injury to operation. Patients were randomly assigned to a short course (24 hours) or a long course (5 days) of antibiotic therapy. All patients received 2 g cefoxitin en route to the operating room and 2 g intravenously piggyback every 6 hours for a total of 1 day vs. 5 days. Sixty-three patients were equally divided into short-course (n = 31) and long-course (n = 32) therapy. This was a high-risk patient population, as assessed by the mean Penetrating Abdominal Trauma Index (33), number of patients with multiple blood transfusions (51 of 63; 81%), number of patients with an Injury Severity Score greater than 15 (37 of 63; 59%), number of patients with destructive colon wounds requiring resection (27 of 63; 43%), and number of patients requiring postoperative critical care (37 of 63; 59%). Differences in intra-abdominal (1-day, 19%; 5-days, 38%) and extra-abdominal (1-day, 45%; 5-days, 25%) infection rates did not achieve statistical significance. There continues to be no evidence that extending antibiotic prophylaxis beyond 24 hours is of benefit, even among the highest risk patients with penetrating abdominal trauma. A large, multi-institutional trial will be necessary to condemn this common practice with statistical validity.

Value of complete cervical helical computed tomographic scanning in identifying cervical spine injury in the unevaluable blunt trauma patient with multiple injuries: a prospective study.

OBJECTIVE: To evaluate the role of routine helical computed tomographic (CT) scan of the entire cervical spine in high-risk patients with multiple injuries. METHODS: Prospective study of patients with severe blunt multiple injuries, requiring intensive care unit admission and CT scan of another body area besides the cervical spine. All patients were evaluated by means of standard cervical spine radiography. A complete cervical spine CT scan was performed during the same trip to the scanner in which other body areas were evaluated. The plain films and the CT scans were read by a radiologist in a blinded manner. RESULTS: Fifty-eight patients fulfilled the criteria for inclusion in the study. The mean Glasgow Coma Scale score was 8.9 and the mean Injury Severity Score was 24.1. Twenty patients (34.4%) had cervical spine injuries (12 stable and 8 unstable injuries). Plain radiography missed eight injuries (including three unstable) and its sensitivity was 60%, specificity 100%, positive predictive value 100%, and negative predictive value 85.1%. The helical CT scan missed two spinal injuries (both stable) and its sensitivity was 90%, specificity was 100%, positive predictive value = 100%, negative predictive value = 95%. CONCLUSION: There is a high incidence of cervical spine injuries in the severe, blunt, multiple-injury, unevaluable patients requiring intensive care unit admission. Plain radiography alone is not reliable in diagnosing many cervical spine injuries. Complete cervical spiral computed tomography is superior to plain radiography. It is suggested that in this selected group of patients, both plain radiography and spiral computed tomography should be performed.

CT cystography versus conventional cystography in evaluation of bladder injury.

OBJECTIVE: The objective of this study was to evaluate prospectively the use of CT cystography, using retrograde filling of the bladder with diluted iodinated contrast material, versus conventional cystography to identify bladder injury in patients with hematuria after blunt abdominal trauma. SUBJECTS AND METHODS: Inclusion criteria consisted of the adult hemodynamically stable abdominal trauma patient with hematuria referred for abdominopelvic CT and also being considered for cystography. An initial abdominopelvic CT scan using IV iodinated contrast material was obtained, as would have been done routinely in the trauma victim. A second CT scan through the pelvis was obtained after retrograde distention of the bladder with dilute iodinated contrast material. CT cystography revealing bladder injury was followed with appropriate therapy. CT cystograms not revealing injury were followed by conventional cystography. Results of patient outcome were evaluated. RESULTS: Over a 21-month period from January 1995 through September 1996, CT cystography was performed on 55 patients who presented with hematuria after blunt abdominal trauma. Five of the 55 patients had bladder injury on CT cystography. The injury in each of these five patients was confirmed intraoperatively. In the remaining 50 patients, both CT and conventional cystography did not reveal bladder injury. CONCLUSION: CT cystography is an accurate method for evaluating bladder injury in the blunt abdominal trauma victim with hematuria. CT cystography, performed in conjunction with routine CT of the abdomen and pelvis for evaluating traumatic hematuria, would therefore preclude conventional cystograms in these patients.

High-frequency percussive ventilation improves oxygenation in patients with ARDS.

STUDY OBJECTIVES: To evaluate changes in respiratory and hemodynamic function of patients with ARDS and requiring high-frequency percussive ventilation (HFPV) after failure of conventional ventilation (CV). DESIGN: Retrospective case series. SETTING: Surgical ICU (SICU) and medical ICU (MICU) of an academic county facility. MEASUREMENTS AND RESULTS: Thirty-two consecutive patients with ARDS (20 from SICU, 12 from MICU) who were unresponsive to at least 48 h of CV and were switched to HFPV were studied. Data on respiratory and hemodynamic parameters were collected during the 48 h preceding and the 48 h after institution of HFPV and compared. Between the period of CV and the period of HFPV, the ratio of PaO2 to the fraction of inspired oxygen (F(IO2)) increased ([mean+/-SE] 130+/-8 vs. 172+/-17; p = 0.027), peak inspiratory pressure (PIP) decreased (39.5+/-1.7 vs. 32.5+/-1.9 mm Hg; p = 0.002), and mean airway pressure(MAP) increased (19.2+/-1.2 vs. 27.5+/-1.4 mm Hg; p<0.001). The rate of change of PaO2/F(IO2) per hour was also significantly improved between the two periods. The same changes in PaO2/F(IO2), PIP, and MAP were observed when the last value recorded while the patients were on CV was compared with the first value recorded after 1 h of HFPV. This improvement was sustained but not amplified during the hours of HFPV. The patterns of improvement in these three parameters were similar in SICU and MICU patients as well as in volume-control and pressure-control patients. There were no changes in hemodynamic parameters. CONCLUSION: The HFPV improves oxygenation by increasing MAP and decreasing PIP. This improvement is achieved soon after institution of HFPV and is maintained without affecting hemodynamics.

Predicting the need for thoracoscopic evacuation of residual traumatic hemothorax: chest radiograph is insufficient.

BACKGROUND: The early removal of large residual posttraumatic hemothorax by videothoracoscopy is increasingly used to avoid the late sequelae of trapped lung and empyema. Plain chest radiography (CXR) is the tool most frequently used to select such cases for operation. Our recent experience has demonstrated that what appears to be a large retained hemothorax on CXR may turn out to be intrapulmonary or extrapleural conditions not amenable to thoracoscopic removal. Our objective was to evaluate the accuracy of CXR in detecting significant residual hemothorax and compare its clinical value to thoracic computed tomography (CT) when used to select patients for thoracoscopic evacuation. METHODS: All patients requiring tube thoracostomy for traumatic hemothorax were prospectively evaluated during a 22-month period (n = 703). Patients who, on the second day after admission, demonstrated opacification on CXR involving more than the costophrenic angle were evaluated by thoracic computed tomography for the presence of undrained fluid. Second-day CXR (CXR2) results were compared with the CT findings. Incorrect interpretation was defined as a difference of more than 300 mL between the two readings. All CXR2 and CT results were reviewed in the same fashion by a radiologist blinded to the surgeon's interpretations. Data on injury mechanism, hemodynamic status, laboratory values, interventions, and outcome were collected prospectively. RESULTS: Fifty-eight patients had clinically significant opacifications on CXR2. The surgeon's and radiologist's CXR2 interpretations were incorrect in 48 and 47% of the cases, respectively. The CT interpretations by the two specialists were in agreement in 97% of the cases. Management that would have been instituted on the basis of CXR2 findings was changed in 18 cases (31%). Twelve patients (21%) required early thoracoscopic evacuation of undrained collections. There was good correlation between the CT estimation and the thoracoscopically retrieved amount of blood. CONCLUSION: Although CXR is useful as a screening tool, it cannot be used to reliably select patients for surgical evacuation of retained traumatic hemothorax. Decision-making should be based on thoracic CT findings.

Colonic resection in trauma: colostomy versus anastomosis.

OBJECTIVES: The management of colonic trauma is well established for simple injuries with primary repair, and ileocolostomy for right-sided injuries that undergo colonic resection. Segmental colon resection for injuries to the left colon can be managed with either an end colostomy or primary anastomosis. A retrospective review was performed to evaluate the outcome and complications associated with colonic resection for trauma to determine the risk factors associated with anastomotic leakage. METHODS: A retrospective review included patients undergoing colonic resection for trauma. The patients were stratified into colostomy, ileocolostomy, and colocolostomy groups. Patient demographics and colon-related complications were collected. Comparison between the colostomy and colocolostomy groups was performed to determine the difference in outcome. The outcome of right-sided colon injuries managed by either an ileocolonic or colocolonic anastomosis was compared. Analysis was performed to identify the factors associated with an increased risk of anastomotic leakage. RESULTS: One hundred forty patients over a 66-month period were included in the analysis. Overall, 41% (57 of 140) of patients developed a colon-related complication; 28% (39 of 140) of patients developed an abscess. Overall, the anastomotic leak rate was 13% (7 of 56) in the colocolostomy group, 4% (2 of 56) in the ileocolostomy group. Right-sided colon injuries managed with a colocolonic anastomosis had a higher incidence of anastomotic leakage than ileocolonic anastomosis, i.e., 14 versus 4% respectively. Of the seven patients who developed a leak from a colocolonic anastomosis, two patients died (29%). Univariate analysis identified an Abdominal Trauma Index Score > or = 25 (p = 0.03) or hypotension in the emergency department (p = 0.001) to be associated with increased risk of developing an anastomotic leak from a colocolonic anastomosis. CONCLUSION: Colonic injuries that are managed with resection are associated with a high complication rate regardless of whether an anastomosis or colostomy is performed. Colonic resection and anastomosis can be performed safely in the majority of patients with severe colonic injury, including injuries to the left colon. For injuries of the right colon, an ileocolostomy has a lower incidence of leakage than a colocolonic anastomosis. For injuries to the left colon, there remains a role for colostomy specifically in the subgroups of patients with a high ATI or hypotension, because these patients are at greater risk for an anastomotic leak. The role of resection and primary anastomosis versus colostomy in colonic trauma requires further investigation.

Invasive and non-invasive physiological monitoring of blunt trauma patients in the early period after emergency admission.

Pulmonary artery catheterization is usually not available to critically injured patients before admission to the intensive care unit, where action to correct values derived from such monitoring may be too late. Methods allowing hemodynamic monitoring during the early stages after trauma need to be explored. We used non-invasive monitoring systems (bioimpedance cardiac output monitoring, pulse oximetry and transcutaneous oximetry) to evaluate early temporal hemodynamic patterns after blunt trauma, and compared these to invasive PA monitoring. We included prospectively 134 patients monitored shortly after admission to the emergency department. The non-invasive impedance cardiac output estimations under extenuating emergency conditions approximated those of the thermodilution method: r = 0.83, r2 = 0.69, P<0.001; bias and precision were -0.02+/-0.78 l/min/m2. In the intensive care unit, these values improved further to: r = 0.91, r2 = 0.83, P<0.001; bias and precision = 0.36+/-0.59 l/min/m2. Monitoring revealed episodes of hypotension, low cardiac index, arterial hemoglobin desaturation, low transcutaneous oxygen and high transcutaneous carbon dioxide tensions, and low oxygen consumption during initial resuscitation. Low flow and poor tissue perfusion were more pronounced in non-survivors by both methods. Multicomponent non-invasive monitoring systems give continuous on-line, real-time displays of physiological data that allow early recognition of circulatory dysfunction. Such systems provide information similar to that provided by the invasive thermodilution method, and are easier and safer to use.

Appropriateness of a 4 mg/kg gentamicin or tobramycin loading dose in post-operative septic shock patients.

OBJECTIVE: To determine the frequency with which early adequate peak serum concentrations (6-12 mg/ litre) can be achieved following a 4 mg/kg loading dose of gentamicin or tobramycin in post-operative septic shock patients. METHOD: Eleven post-operative septic shock patients were grouped into (i) a control group (n=7) who received the conventional gentamicin or tobramycin dosing regimen of 2 mg/kg loading dose followed by a maintenance dose of approximately 1.5mg/kg (peak and trough levels were measured after the third dose), and (ii) a study group (n = 4) who received a tobramycin or gentamicin 4 mg/kg loading dose, followed by 30 min, 3 h and 16 h serum drug level measurements. Pharmacokinetic parameters were calculated using a one-compartmental model. Differences in both groups were determined using Student's t-test. RESULTS: Pharmacokinetic parameters in both groups showed no statistically significant difference. The dose from which peak levels were drawn was significantly higher in the study group (4 mg/kg vs. 1.66 mg/kg; P = 0.001), which also resulted in higher but adequate peak serum concentrations (8.9+/-2.2 vs. 4.8+/-1.8 mg/litre). In the study group, linear regression analysis showed significant relationships between dose and peak concentrations and volume of distribution and peak concentrations (r = 0.96, P= 0.01 and r= -0.96, P= 0.01, respectively). CONCLUSION: One hundred per cent of the post-operative septic shock patients achieved target peak serum concentrations (mean 8.9+/-2.2 mg/litre) following a 4 mg/kg tobramycin or gentamicin loading dose. An expanded Vd (0.46+/-0.13 litres/kg) was also observed.