Acute Kidney Injury in Critically Ill Vascular Surgery Patients is Common and Associated with Increased Mortality

INTRODUCTION

Vascular surgery patients have multiple risk factors for renal dysfunction, but acute kidney injury (AKI) is poorly studied in this group. The purpose of this study was to define the incidence, risk factors, and outcomes of AKI in high-risk vascular patients.

METHODS

Critically ill vascular surgery patients admitted during January-December 2012 were retrospectively analyzed with 1-year follow-up. The endpoint was AKI by established RIFLE creatinine criteria. The primary analysis was between patients with or without AKI, with secondary analysis of post-operative AKI. Outcomes were inpatient and 1-year mortality, inpatient lengths of stay, and discharge renal function.

RESULTS

One-hundred and thirty six vascular surgery patients were included, representing 27% of all vascular surgery admissions during the study period. Sixty-five (48%) developed AKI. Independent global risk factors for AKI were diabetes, increasing critical illness severity, and sepsis. While intraoperative blood loss and hypotension were associated with subsequent renal dysfunction, post-operative AKI rates were similar for patients undergoing aortic, carotid, endovascular, or peripheral vascular procedures. All RIFLE grades of AKI were associated with worse outcomes. Overall, patients with AKI had significantly increased short- and long-term mortality, longer inpatient lengths of stay, and worse discharge renal function.

CONCLUSION

AKI is common among critically ill vascular surgery patients. Importantly, the type of surgical procedure appears to be less important than intra- and perioperative management in determining renal dysfunction. Regardless of its severity, AKI is a clinically significant complication that is associated with substantially worse patient outcomes.

Transfusion of plasma, platelets, and red blood cells in a 1:1:1 vs a 1:1:2 ratio and mortality in patients with severe trauma: the PROPPR randomized clinical trial

IMPORTANCE

Severely injured patients experiencing hemorrhagic shock often require massive transfusion. Earlier transfusion with higher blood product ratios (plasma, platelets, and red blood cells), defined as damage control resuscitation, has been associated with improved outcomes; however, there have been no large multicenter clinical trials.

OBJECTIVE

To determine the effectiveness and safety of transfusing patients with severe trauma and major bleeding using plasma, platelets, and red blood cells in a 1:1:1 ratio compared with a 1:1:2 ratio.

DESIGN, SETTING, AND PARTICIPANTS

Pragmatic, phase 3, multisite, randomized clinical trial of 680 severely injured patients who arrived at 1 of 12 level I trauma centers in North America directly from the scene and were predicted to require massive transfusion between August 2012 and December 2013.

INTERVENTIONS

Blood product ratios of 1:1:1 (338 patients) vs 1:1:2 (342 patients) during active resuscitation in addition to all local standard-of-care interventions (uncontrolled).

MAIN OUTCOMES AND MEASURES

Primary outcomes were 24-hour and 30-day all-cause mortality. Prespecified ancillary outcomes included time to hemostasis, blood product volumes transfused, complications, incidence of surgical procedures, and functional status.

RESULTS

No significant differences were detected in mortality at 24 hours (12.7% in 1:1:1 group vs 17.0% in 1:1:2 group; difference, -4.2% [95% CI, -9.6% to 1.1%]; P = .12) or at 30 days (22.4% vs 26.1%, respectively; difference, -3.7% [95% CI, -10.2% to 2.7%]; P = .26). Exsanguination, which was the predominant cause of death within the first 24 hours, was significantly decreased in the 1:1:1 group (9.2% vs 14.6% in 1:1:2 group; difference, -5.4% [95% CI, -10.4% to -0.5%]; P = .03). More patients in the 1:1:1 group achieved hemostasis than in the 1:1:2 group (86% vs 78%, respectively; P = .006). Despite the 1:1:1 group receiving more plasma (median of 7 U vs 5 U, P < .001) and platelets (12 U vs 6 U, P < .001) and similar amounts of red blood cells (9 U) over the first 24 hours, no differences between the 2 groups were found for the 23 prespecified complications, including acute respiratory distress syndrome, multiple organ failure, venous thromboembolism, sepsis, and transfusion-related complications.

CONCLUSIONS AND RELEVANCE

Among patients with severe trauma and major bleeding, early administration of plasma, platelets, and red blood cells in a 1:1:1 ratio compared with a 1:1:2 ratio did not result in significant differences in mortality at 24 hours or at 30 days. However, more patients in the 1:1:1 group achieved hemostasis and fewer experienced death due to exsanguination by 24 hours. Even though there was an increased use of plasma and platelets transfused in the 1:1:1 group, no other safety differences were identified between the 2 groups.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01545232.

Responsiveness to therapy for increased intracranial pressure in traumatic brain injury is associated with neurological outcome

In patients with severe traumatic brain injury, increased intracranial pressure (ICP) is associated with poor functional outcome or death. Hypertonic saline (HTS) is a hyperosmolar therapy commonly used to treat increased ICP; this study aimed to measure initial patient response to HTS and look for association with patient outcome. Patients >17 years old, admitted and requiring ICP monitoring between 2008 and 2010 at a large urban tertiary care facility were retrospectively enrolled. The first dose of hypertonic saline administered after admission for ICP >19mmHg was recorded and correlated with vital signs recorded at the bedside. The absolute and relative change in ICP at 1 and 2h after HTS administration was calculated. Patients were stratified by mortality and long-term (≥6 months) functional neurological outcome. We identified 46 patients who received at least 1 dose of HTS for ICP>19, of whom 80% were male, mean age 34.4, with a median post-resuscitation GCS score of 6. All patients showed a significant decrease in ICP 1h after HTS administration. Two hours post-administration, survivors showed a further decrease in ICP (43% reduction from baseline), while ICP began to rebound in non-survivors (17% reduction from baseline). When patients were stratified for long-term neurological outcome, results were similar, with a significant difference in groups by 2h after HTS administration. In patients treated with HTS for intracranial hypertension, those who survived or had good neurological outcome, when compared to those who died or had poor outcomes, showed a significantly larger sustained decrease in ICP 2h after administration. This suggests that even early in a patient's treatment, treatment responsiveness is associated with mortality or poor functional outcome. While this work is preliminary, it suggests that early failure to obtain a sustainable response to hyperosmolar therapy may warrant greater treatment intensity or therapy escalation.

Management of fractures in a geriatric surgical patient

Trauma is an increasingly common problem in geriatric patients; fractures are frequent among the elderly. Life expectancy continues to rise. Advances in medical care allow people to live longer and better lives. Medications, surgical advances (treatment for coronary artery disease, coronary bypass grafting), and joint replacement surgery can be safely performed in elderly patients. Thus, geriatric patients are no longer confined to a life of inactivity. They are out of their homes and interacting in the community, exercising and leading active lives. Thus, they are more likely to become injured and present to trauma centers for care.

Permutation entropy analysis of vital signs data for outcome prediction of patients with severe traumatic brain injury

Permutation entropy is computationally efficient, robust to outliers, and effective to measure complexity of time series. We used this technique to quantify the complexity of continuous vital signs recorded from patients with traumatic brain injury (TBI). Using permutation entropy calculated from early vital signs (initial 10-20% of patient hospital stay time), we built classifiers to predict in-hospital mortality and mobility, measured by 3-month Extended Glasgow Outcome Score (GOSE). Sixty patients with severe TBI produced a skewed dataset that we evaluated for accuracy, sensitivity and specificity. The overall prediction accuracy achieved 91.67% for mortality, and 76.67% for 3-month GOSE in testing datasets, using the leave-one-out cross validation. We also applied Receiver Operating Characteristic analysis to compare classifiers built from different learning methods. Those results support the applicability of permutation entropy in analyzing the dynamic behavior of TBI vital signs for early prediction of mortality and long-term patient outcomes.

Pharmacologic Treatment Reduces Pressure Times Time Dose and Relative Duration of Intracranial Hypertension

INTRODUCTION

Past work has shown the importance of the "pressure times time dose" (PTD) of intracranial hypertension (intracranial pressure [ICP] > 19 mm Hg) in predicting outcome after severe traumatic brain injury. We used automated data collection to measure the effect of common medications on the duration and dose of intracranial hypertension.

METHODS

Patients >17 years old, admitted and requiring ICP monitoring between 2008 and 2010 at a single, large urban tertiary care facility, were retrospectively enrolled. Timing and dose of ICP-directed therapy were recorded from paper and electronic medical records. The ICP data were collected automatically at 6-second intervals and averaged over 5 minutes. The percentage of time of intracranial hypertension (PTI) and PTD (mm Hg h) were calculated.

RESULTS

A total of 98 patients with 664 treatment instances were identified. Baseline PTD ranged from 27 (before administration of propofol and fentanyl) to 150 mm Hg h (before mannitol). A "small" dose of hypertonic saline (HTS; ≤250 mL 3%) reduced PTD by 38% in the first hour and 37% in the second hour and reduced the time with ICP >19 by 38% and 39% after 1 and 2 hours, respectively. A "large" dose of HTS reduced PTD by 40% in the first hour and 63% in the second (PTI reduction of 36% and 50%, respectively). An increased dose of propofol or fentanyl infusion failed to decrease PTD but reduced PTI between 14% (propofol alone) and 30% (combined increase in propofol and fentanyl, after 2 hours). Barbiturates failed to decrease PTD but decreased PTI by 30% up to 2 hours after administration. All reductions reported are significantly changed from baseline, P < .05.

CONCLUSION

Baseline PTD values before drug administration reflects varied patient criticality, with much higher values seen before the use of mannitol or barbiturates. Treatment with HTS reduced PTD and PTI burden significantly more than escalation of sedation or pain management, and this effect remained significant at 2 hours after administration.

A new aortic injury score predicts early rupture more accurately than clinical assessment

OBJECTIVE

The optimal timing for repair of a high-grade blunt thoracic aortic injury (BTAI) is uncertain. Delayed repair is common and associated with improved outcomes, but some lesions may rupture during observation. To determine optimal patient selection for appropriate management, we developed a pilot clinical risk score to evaluate aortic stability and predict rupture.

METHODS

Patients presenting in stable condition with Society for Vascular Surgery grade III or IV BTAI diagnosed on computed tomography (CT) were retrospectively reviewed. To determine clinical and radiographic factors associated with aortic rupture, patients progressing to aortic rupture (defined by contrast extravasation on CT or on operative or autopsy findings) were compared with those who had no intervention ≤48 hours of admission. A model targeting 100% sensitivity for rupture was generated and internally validated by bootstrap analysis. Clinical utility was tested by comparison with clinical assessment by surgeons experienced in BTAI management who were provided with CT images and clinical data but were blinded to outcome.

RESULTS

The derivation cohort included 18 patients whose aorta ruptured and 31 with stable BTAI. There was no difference in age, gender, injury mechanism, nonchest injury severity, blood pressure, or Glasgow Coma Scale on admission between patient groups. As dichotomous factors, admission lactate >4 mM, posterior mediastinal hematoma >10 mm, and lesion/normal aortic diameter ratio >1.4 on the admission CT were independently associated with aortic rupture. The model had an area under the receiver operator curve of .97, and in the presence of any two factors, was 100% sensitive and 84% specific for predicting aortic rupture. No aortic lesions ruptured in patients with fewer than two factors. In contrast, clinical assessment had lower accuracy (65% vs 90% total accuracy, P < .01).

CONCLUSIONS

This novel risk score can be applied on admission using clinically relevant factors that incorporate patient physiology, size of the aortic lesion, and extent of the mediastinal hematoma. The model reliably identifies and distinguishes patients with high-grade BTAI who are at risk for early rupture from those with stable lesions. Although preliminary, because it is more accurate than clinical assessment alone, the score may improve patient selection for emergency or delayed intervention.

Intracranial pressure response after pharmacologic treatment of intracranial hypertension

BACKGROUND

The accepted treatment of increased intracranial pressure (ICP) in patients experiencing severe traumatic brain injury is multimodal and algorithmic, obscuring individual effects of treatment. Using continuous vital signs monitoring, we sought to measure treatment effect and ascertain the accuracy of manual data recording.

METHODS

Patients older than 17 years, admitted and requiring ICP monitoring between 2008 and 2010 at a high-volume urban trauma center, were retrospectively evaluated. Timing and dose of ICP-directed therapy were recorded from paper and electronic medical records. ICP data were collected automatically at 6-second intervals and from manual charts. A statistical mixed model was applied to all data to account for multiple sampling.

RESULTS

A total of 117 patients met inclusion criteria; 450 treatments were administered when nursing records indicate an ICP greater than 20 mm Hg, while 968 treatments were given when ICP was greater than 20 mm Hg by automated data. Pharmacologic treatments identified include hypertonic saline (HTS), mannitol, barbiturates, and dose escalations of propofol or fentanyl infusions. Treatment with HTS resulted in the largest ICP decrease of the treatments examined, with a 1-hour ICP reduction of 8.8/9.9 mm Hg (for a small/large dose) according to manual data and a reduction of 3.0/2.4 mm Hg according to automated data. Propofol and fentanyl escalations resulted in smaller but significant ICP reductions. Mannitol (n = 8) resulted in statistically insignificant trends down in the first hour but rebounded by the second hour after administration. The average ICP in the hour before medication administration was higher for barbiturates (27 mm Hg) and mannitol (32 mm Hg) than for the other interventions (18-19 mm Hg).

CONCLUSION

ICP fell after administration of HTS, mannitol, or barbiturates and showed continued improvement after 2 hours. ICP fell initially after treatment with short-acting propofol and fentanyl but trended back up after 2 hours. Manually recorded data consistently overestimated treatment effectiveness. Automated data collection gives a more accurate assessment of patient status and responsiveness to treatment.

LEVEL OF EVIDENCE

Therapeutic study, level IV.

Loop versus end colostomy reversal: has anything changed?

PURPOSE

Though primary repair of colon injuries is preferred, certain injury patterns require colostomy creation. Colostomy reversal is associated with significant morbidity and healthcare cost. Complication rates may be influenced by technique of diversion (loop vs. end colostomy), though this remains ill-defined. We hypothesized that reversal of loop colostomies is associated with fewer complications than end colostomies.

METHODS

This is a retrospective, multi-institutional study (four, level-1 trauma centers) of patients undergoing colostomy takedown for trauma during the time period 1/2006-12/2012. Data were collected from index trauma admission and subsequent admission for reversal and included demographics and complications of reversal. Student's t test was used to compare continuous variables against loop versus end colostomy. Discrete variables were compared against both groups using Chi-squared tests.

RESULTS

Over the 6-year study period, 218 patients underwent colostomy takedown after trauma with a mean age of 30; 190 (87%) were male, 162 (74%) had penetrating injury as their indication for colostomy, and 98 (45%) experienced at least one complication. Patients in the end colostomy group (n = 160) were more likely to require midline laparotomy (145 vs. 18, p < 0.001), had greater intra-operative blood loss (260.7 vs. 99.4 mL, p < 0.001), had greater hospital length of stay (8.4 vs. 5.5 days, p < 0.001), and had more overall complications (81 vs. 17, p = 0.005) than patients managed with loop colostomy (n = 58).

CONCLUSIONS

Local takedown of a loop colostomy is safe and leads to shorter hospital stays, less intra-operative blood loss, and fewer complications when compared to end colostomy.

Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) Trial: design, rationale and implementation

BACKGROUND

Forty percent of in-hospital deaths among injured patients involve massive truncal haemorrhage. These deaths may be prevented with rapid haemorrhage control and improved resuscitation techniques. The Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) Trial was designed to determine if there is a difference in mortality between subjects who received different ratios of FDA approved blood products. This report describes the design and implementation of PROPPR.

STUDY DESIGN

PROPPR was designed as a randomized, two-group, Phase III trial conducted in subjects with the highest level of trauma activation and predicted to have a massive transfusion. Subjects at 12 North American level 1 trauma centres were randomized into one of two standard transfusion ratio interventions: 1:1:1 or 1:1:2, (plasma, platelets, and red blood cells). Clinical data and serial blood samples were collected under Exception from Informed Consent (EFIC) regulations. Co-primary mortality endpoints of 24h and 30 days were evaluated.

RESULTS

Between August 2012 and December 2013, 680 patients were randomized. The overall median time from admission to randomization was 26min. PROPPR enrolled at higher than expected rates with fewer than expected protocol deviations.

CONCLUSION

PROPPR is the largest randomized study to enrol severely bleeding patients. This study showed that rapidly enrolling and successfully providing randomized blood products to severely injured patients in an EFIC study is feasible. PROPPR was able to achieve these goals by utilizing a collaborative structure and developing successful procedures and design elements that can be part of future trauma studies.

Time to first take-back operation predicts successful primary fascial closure in patients undergoing damage control laparotomy

BACKGROUND

Failure to achieve primary fascial closure (PFC) after damage control laparotomy is costly and carries great morbidity. We hypothesized that time from the initial laparotomy to the first take-back operation would be predictive of successful PFC.

METHODS

Trauma patients managed with open abdominal techniques after damage control laparotomy were prospectively followed at 14 Level 1 trauma centers during a 2-year period. Time to the first take-back was evaluated as a predictor of PFC using hierarchical multivariate logistic regression analysis.

RESULTS

A total of 499 patients underwent damage control laparotomy and were included in this analysis. PFC was achieved in 327 (65.5%) patients. Median time to the first take-back operation was 36 hours (interquartile range 24-48). After we adjusted for patient demographics, resuscitation volumes, and operative characteristics, increasing time to the first take-back was associated with a decreased likelihood of PFC. Specifically, each hour delay in return to the operating room (24 hours after initial laparotomy) was associated with a 1.1% decrease in the odds of PFC (odds ratio 0.989; 95% confidence interval 0.978-0.999; P = .045). In addition, there was a trend towards increased intra-abdominal complications in patients returning after 48 hours (odds ratio 1.80; 95% confidence interval 1.00-3.25; P = .05).

CONCLUSION

Data from this prospective, multicenter study demonstrate that delays in returning to the operating room after damage control laparotomy are associated with reductions in PFC. These findings suggest that emphasis should be placed on returning to the operating room within 24 hours after the initial laparotomy if possible (and no later than 48 hours).

Splenic Embolization Decreases Infectious Complications and Resource Utilization Compared to Splenectomy in Severely Injured Patients

Introduction. Increasing use of main coil angioembolization for splenic injury has raised concerns of increased complication rates and resource utilization compared to splenectomy. This study examined complication rates for severely injured patients undergoing splenectomy versus main coil angioembolization. Methods. Demographic data (age, sex, and race), Injury Severity Score (ISS), and splenic injury grade were collected prospectively on all patients admitted to the intensive care unit with blunt splenic injury treated with splenectomy or main coil angioembolization. Outcome measures (transfusion requirements, mechanical ventilation use and duration, mortality, intensive care unit and hospital length of stay, infection rate, and systemic inflammatory response syndrome or SIRS score) were reviewed daily. Results. Of 116 patients reviewed, 65 underwent splenectomy and 51 underwent main coil angioembolization. Groups were comparable for age, sex, race, and mechanism of injury. Splenectomized patients had a higher ISS (41 vs 31) and splenic injury grade (3.7 vs 3.2). The main coil angioembolization group had a lower transfusion requirement, hospital length of stay, incidence of mechanical ventilation, nosocomial infection rate, and SIRS score. Overall, mortality and ventilator days were lower but not statistically significant. Conclusions. Severely injured patients treated with splenectomy had significantly higher infection rates and resource utilization compared to those treated with main coil angioembolization.

Successful implementation of a unit-based quality nurse to reduce central line-associated bloodstream infections

BACKGROUND

Central line (CL)-associated bloodstream infections (CLABSI) are an important cause of patient morbidity and mortality. Novel strategies to prevent CLABSI are needed.

METHODS

We described a quasiexperimental study to examine the effect of the presence of a unit-based quality nurse (UQN) dedicated to perform patient safety and infection control activities with a focus on CLABSI prevention in a surgical intensive care unit (SICU).

RESULTS

From July 2008 to March 2012, there were 3,257 SICU admissions; CL utilization ratio was 0.74 (18,193 CL-days/24,576 patient-days). The UQN program began in July 2010; the nurse was present for 30% (193/518) of the days of the intervention period of July 2010 to March 2012. The average CLABSI rate was 5.0 per 1,000 CL-days before the intervention and 1.5 after the intervention and decreased by 5.1% (P = .005) for each additional 1% of days of the month that the UQN was present, even after adjusting for CLABSI rates in other adult intensive care units, time, severity of illness, and Comprehensive Unit-based Safety Program participation (5.1%, P = .004). Approximately 11.4 CLABSIs were prevented.

CONCLUSION

The presence of a UQN dedicated to perform infection control activities may be an effective strategy for CLABSI reduction.

Timing of intracranial hypertension following severe traumatic brain injury

BACKGROUND

We asked whether continuous intracranial pressure (ICP) monitoring data could provide objective measures of the degree and timing of intracranial hypertension (ICH) in the first week of neurotrauma critical care and whether such data could be linked to outcome.

METHODS

We enrolled adult (>17 years old) patients admitted to our Level I trauma center within 6 h of severe TBI. ICP data were automatically captured and ICP 5-minute means were grouped into 12-hour time periods from admission (hour 0) to >7 days (hour 180). Means, maximum, percent time (% time), and pressure-times-time dose (PTD, mmHg h) of ICP >20 mmHg and >30 mmHg were calculated for each time period.

RESULTS

From 2008 to 2010, we enrolled 191 patients. Only 2.1% had no episodes of ICH. The timing of maximum PTD20 was relatively equally distributed across the 15 time periods. Median ICP, PTD20, %time20, and %time30 were all significantly higher in the 84-180 h time period than the 0-84 h time period. Stratified by functional outcome, those with poor functional outcome had significantly more ICH in hours 84-180. Multivariate analysis revealed that, after 84 h of monitoring, every 5% increase in PTD20 was independently associated with 21% higher odds of having a poor functional outcome (adjusted odds ratio = 1.21, 95% CI 1.02-1.42, p = 0.03).

CONCLUSIONS

Although early elevations in ICP occur, ICPs are the highest later in the hospital course than previously understood, and temporal patterns of ICP elevation are associated with functional outcome. Understanding this temporal nature of secondary insults has significant implications for management.

Independent predictors of enteric fistula and abdominal sepsis after damage control laparotomy: results from the prospective AAST Open Abdomen registry

IMPORTANCE

Enterocutaneous fistula (ECF), enteroatmospheric fistula (EAF), and intra-abdominal sepsis/abscess (IAS) are major challenges for surgeons caring for patients undergoing damage control laparotomy after trauma.

OBJECTIVE

To determine independent predictors of ECF, EAF, or IAS in patients undergoing damage control laparotomy after trauma, using the AAST Open Abdomen Registry.

DESIGN

The AAST Open Abdomen registry of patients with an open abdomen following damage control laparotomy was used to identify patients who developed ECF, EAF, or IAS and to compare these patients with those without these complications. Univariate analyses were performed to compare these groups of patients. Variables from univariate analyses differing at P < .20 were entered into a stepwise logistic regression model to identify independent risk factors for ECF, EAF, or IAS.

SETTING

Fourteen level I trauma centers.

PARTICIPANTS

A total of 517 patients with an open abdomen following damage control laparotomy.

MAIN OUTCOMES AND MEASURES

Complication of ECF, EAF, or IAS.

RESULTS

More patients in the ECF/EAF/IAS group than in the group without these complications underwent bowel resection (63 of 111 patients [57%] vs 133 of 406 patients [33%]; P < .001). Within the first 48 hours after surgery, the ECF/EAF/IAS group received more colloids (P < .03) and total fluids (P < .03) than did the group without these complications. The ECF/EAF/IAS group underwent almost twice as many abdominal reexplorations as did the group without these complications (mean [SD] number, 4.1 [4.1] vs 2.2 [3.4]; P < .001). After multivariate analysis, the independent predictors of ECF/EAF/IAS were a large bowel resection (adjusted odds ratio [AOR], 3.56 [95% CI, 1.88-6.76]; P < .001), a total fluid intake at 48 hours of between 5 and 10 L (AOR, 2.11 [95% CI, 1.15-3.88]; P = .02) or more than 10 L (AOR, 1.93 [95% CI, 1.04-3.57]; P = .04), and an increasing number of reexplorations (AOR, 1.14 [95% CI, 1.06-1.21]; P < .001).

CONCLUSIONS AND RELEVANCE

Large bowel resection, large-volume fluid resuscitation, and an increasing number of abdominal reexplorations were statistically significant predictors of ECF, EAF, or IAS in patients with an open abdomen after damage control laparotomy.

Post-traumatic empyema: aetiology, surgery and outcome in 125 consecutive patients

INTRODUCTION

Empyema remains a potentially serious condition with multiple etiologies including post-pneumonic, post-resection, and post-traumatic. There are few studies describing the latter. We reviewed our experience at a high volume trauma centre in injured patients with empyema, examining pre-operative status, surgical procedures, pathogens and outcome.

METHODS

Retrospective trauma registry review, from 9/01 to 4/10. Empyema was defined as culture positive pleural fluid or purulence at operation. Data collected included demographics, injury mechanism, thoracic injuries, organ dysfunction, pathogens isolated, surgical procedures, outcomes and follow up.

RESULTS

One hundred twenty-five consecutive patients with empyema were identified. Average injury severity score and age were 27.3 and 37.2 years respectively; 89.6% were male, 63.2% sustained blunt chest trauma. Time from injury to diagnosis averaged 12.1 days. All underwent decortication; 80% by thoracotomy, the remainder thoracoscopically. At operation over half were mechanically ventilated and 13.6% required vasoactive infusions. Monomicrobial cultures with Gram positive cocci predominating were obtained in 44%, 48% had polymicrobial cultures and 18.4% had a ruptured lung abscess. There were five deaths (4%); two occurring after a ruptured lung abscess. Recurrent empyema occurred in 6.4%, all successfully treated by re-operation or catheter drainage. Intensive care and hospital stays were 18.1 and 30.6 days respectively. All survivors achieved resolution of empyema.

CONCLUSIONS

Trauma patients with empyema represent a subset of severely injured critically ill patients with diverse pathogens and polymicrobial flora. Appropriate surgical management and specific antibiotic therapy yields excellent results with acceptable risk. A ruptured lung abscess may be the aetiology of the post-traumatic empyema in a subset of patients and may represent an increased operative risk.

Comparison study of acellular dermal matrices in complicated hernia surgery

BACKGROUND

Damage control surgery and management of the open abdomen has led to a significant improvement in survival in trauma and emergency surgical patients. However, subsequent abdominal reconstruction has become a significant challenge. The objective of this study was to compare 2 different acellular dermal matrices in regard to hernia recurrence and complications in patients who present with a large complicated ventral hernia as a result of trauma or emergency surgery.

STUDY DESIGN

A prospective quasi-experimental time-interrupted series design was used to evaluate the incidence of hernia recurrence in trauma/emergency surgery patients who had a ventral hernia repair with a biologic matrix. From January 2005 to December 2007, 55 patients with a complicated ventral hernia were repaired with AlloDerm (Life Cell Corporation). Beginning in February 2008 to January 2010, 40 patients with the same criteria were repaired with FlexHD (Musculoskeletal Transplant Foundation) and followed prospectively over the following year. The primary outcome for this study was hernia recurrence (functional or real) at 1 year. Other outcomes variables included abdominal laxity, seroma formation, and wound or intra-abdominal infection.

RESULTS

There was no significant difference in age, sex, and body mass index between the groups. In addition, there was no significant difference in the mean hernia size and size of the acellular dermis that was inserted. At 1 year postsurgery, all of the AlloDerm patients were diagnosed with recurrence requiring a second formal repair. Eleven patients (31%) whose hernias were repaired with FlexHD were diagnosed with a recurrence requiring a second formal repair.

CONCLUSIONS

FlexHD appears to have reduced the recurrence and laxity rates while maintaining a similar complication profile compared with AlloDerm in trauma/emergency surgery patients with large complicated ventral hernias.

Capillary leak syndrome in trauma: what is it and what are the consequences?

TICS is a complex disease that is clearly multifactorial in the traumatically injured patient (Fig. 2). Although systemic inflammation that occurs directly as a result of injury plays the most prominent role, the local tissue and organ injury effects of trauma not only cause local capillary leak and edema but also further amplify the SIRS response. High volume fluid administration and hypoproteinemic states further exacerbate the problem. All of this leads to organ dysfunction and failure, which is the third leading cause of death following injury. Strategies to treat TICS and attenuate its effects once it occurs by targeting inflammatory pathways have been wholly unsuccessful. The mainstay of therapy for TICS is prevention and minimization of its lethal effects. Newer resuscitation strategies such as hemostatic resuscitation and early goal-directed therapies are currently the best available strategies to combat TICS. Whether these result in better outcomes remains to be seen and the authors anxiously await the results of well-designed prospective trials.

The clinical significance of platelet counts in the first 24 hours after severe injury

BACKGROUND

Admission platelet (PLT) counts are known to be associated with all-cause mortality for seriously injured patients admitted to a trauma center. The course of subsequent PLT counts, their implications, and the effects of PLT therapy are less well known.

STUDY DESIGN AND METHODS

Trauma center patients who were directly admitted from the scene of injury, received 1 or more units of uncrossmatched red blood cells in the first hour of care, survived for at least 15 minutes, and had a PLT count measured in the first hour were analyzed for the association of their admission and subsequent PLT counts in the first 24 hours with injury severity and hemorrhagic and central nervous system (CNS) causes of in-hospital mortality.

RESULTS

Over an 8.25-year period, 1292 of 45,849 direct trauma admissions met entry criteria. Admission PLT counts averaged 228×10(9) ±90×10(9) /L and decreased by 104×10(9) /L by the second hour and 1×10(9) /L each hour thereafter. The admission count was not related to time to admission. Each 1-point increase in the injury severity score was associated with a 1×10(9) /L decrease in the PLT count at all times in the first 24 hours of care. Admission PLT counts were strongly associated with hemorrhagic and CNS injury mortality and subsequent PLT counts. Effects of PLT therapy could not be ascertained.

DISCUSSION

Admission PLT counts in critically injured trauma patients are usually normal, decreasing after admission. Low PLT counts at admission and during the course of trauma care are strongly associated with mortality.

Infectious complications in GSW's through the gastrointestinal tract into the spine

BACKGROUND

Trans-gastrointestinal tract GSW's to the spine are devastating injuries with significant potential for infectious complications. We sought to address antimicrobial management of these injuries.

METHODS

We retrospectively analysed all patients with penetrating trauma through the GI tract into the spine admitted to a level I trauma centre from 1/02 to 12/09. Patients were excluded if they died within 24h. Patients received 24-48 h of peri-operative prophylactic antibiotics, except in damage control where antibiotics were continued until packs were removed.

RESULTS

51 patients were included. 94% were male with a mean age of 27 years. The mean ISS was 28 (9-50). The mean length of stay was 19 days (3-53) and mortality was 9.8%. The mean follow up period was 277 days (0-1765). There were 12 gastric, 25 small bowel, 26 colonic, and 4 esophageal injuries. There were 48 exploratory laparotomies, of which 12 were damage control procedures. 18 patients had no infections. There were 20 abdominal infections and 7 surgical wound infections. There were 23 infections not related to the abdomen. One patient developed a CNS infection 4 days after discharge despite receiving a two week course of piperacillin/tazobactam for Escherichia coli bacteremia during his initial hospital stay. There were no other CNS infections.

CONCLUSION

Despite the potential for significant deep infections of the spine, standard antimicrobial prophylaxis is sufficient for the initial management of these patients.

Use of serum biomarkers to predict cerebral hypoxia after severe traumatic brain injury

The management of severe traumatic brain injury (TBI) focuses on prevention and treatment of secondary insults such as cerebral hypoxia (CH). There are a number of biomarkers that are thought to play a part in secondary injury following severe TBI. This study evaluates the association between S100β, neuron-specific enolase (NSE), and glial fibrillary acidic protein (GFAP), detected in the serum of severe TBI patients and CH as measured by brain tissue oxygen partial pressure (Pbo(2)). Patients with severe TBI were prospectively enrolled. Pressure times time (PTD; mm Hg*h), measuring the depth and duration of CH, was calculated for 12-h periods for episodes of moderate (Pbo(2) < 20 mm Hg) and severe (Pbo(2) < 15 mm Hg) CH, and compared to serum levels of S100β, NSE, and GFAP drawn prior to periods of monitoring. An adjusted mixed model analysis was applied as was receiver operating characteristic (ROC) curve analysis. Of 76 patients enrolled, 24 had Pbo(2) monitoring. One hundred and thirty serum samples were matched with 12-h periods of monitoring. Significant associations were found in adjusted analyses between increasing serum levels of S100β (coefficient=0.57, 0.56; p<0.001), NSE (coefficient=0.48, 0.52; p<0.001), and GFAP (coefficient=0.29, 0.30; p=0.003 and 0.002), and increasing PTD of moderate (Pbo(2)<20 mm Hg) and severe (Pbo(2)<15 mm Hg) CH. AUCs for the prediction of moderate and severe CH were 0.62 and 0.66 for S100β, 0.55 and 0.71 for NSE, and 0.50 and 0.62 for GFAP, respectively. Specificities were between 76% and 90% for S100β and NSE. S100β, NSE, and GFAP demonstrate promise as candidate serum markers of impending CH. The fact that these biomarker elevations occur prior to the onset of clinical manifestations suggests that we may be able to predict imminent events following TBI. Given the morbidity of CH, early intervention and prevention may have a significant impact on outcomes and help guide decisions about the timing of interventions.

Effect of glycemic state on hospital mortality in critically ill surgical patients

Intensive insulin therapy can reduce mortality. Hypoglycemia related to intensive therapy may worsen outcomes. This study compared risk adjusted mortality for different glycemic states. A retrospective review of patients admitted to a surgical intensive care unit over 4 years was performed. Patients were divided into glycemic groups: HYPER (≥1 episode > 180 mg/dL, any <60), HYPO (≥1 episode < 60 mg/dL, any >180), BOTH (≥1 episode < 60 and ≥1 episode > 180 mg/dL), NORMO (all episodes 60-180 mg/dL), HYPER-Only (≥1 episode > 180, none <60 mg/dL), and HYPO-Only (≥1 episode < 60, none >180 mg/dL). Observed to expected Acute Physiology and Chronic Health Evaluation (APACHE) III mortality ratios (O/E) were studied. Number of adverse glycemic events was compared with mortality. Hypoglycemia and hyperglycemia occurred in 18 per cent and 50 per cent of patients. Mortality was 12.4 per cent (O/E = 0.88). BOTH had the highest O/E ratio (1.43) with HYPO the second highest (1.30). Groups excluding hypoglycemia (NORMO and HYPER-only) had the lowest O/E ratios: 0.56 and 0.88. Increasing number of hypoglycemic events were associated with increasing O/E ratio: 0.69 O/E for no events, 1.19 for 1-3 events, 1.35 for 4-6 events, 1.9 for 7-9 events, and 3.13 for ≥ 10 events. Ten or more hyperglycemic events were needed to significantly associate with worse mortality (O/E 1.53). Hyper- and hypoglycemia increase mortality compared with APACHE III expected mortality, with highest mortality risk if both are present. Hypoglycemia is associated with worse risk. Glucose control may need to be loosened to prevent hypoglycemia and reduce glucose variability.

Trauma readiness training for military deployment: a comparison between a U.S. trauma center and an Air Force Theater Hospital in Balad, Iraq

The U.S. Air Force created the Center for Sustainment of Trauma and Readiness Skills at the Shock Trauma Center (STC) where staffs rotate before deployment. We sought to investigate the value of this training. A retrospective review of prospectively collected data of patient volume, injury severity, mechanism of injury, operative cases, and massive transfusion data from September 2006 to August 2007 was obtained from the STC in Baltimore and the Air Force Theater Hospital (AFTH) in Balad. Severity of injury and massive transfusions were higher at the AFTH. Soft tissue wound care represented approximately 25% of AFTH cases; a soft tissue service performed 465 operative debridements for severe soft tissue infections at STC. The STC's high-volume of major soft tissue debridement cases may offer the closest approximation of high energy wound care. Training at selected U.S. trauma centers may prepare military staff to care for war injuries, particularly those who do not practice in high-volume Level 1 trauma centers.

Transfusion medicine in trauma patients: an update

In 2008, we reviewed the practical interface between transfusion medicine and the surgery and critical care of severely injured patients. Reviewed topics ranged from epidemiology of trauma to patterns of resuscitation to the problems of transfusion reactions. In the interim, trauma specialists have adopted damage control resuscitation and become much more knowledgeable and thoughtful about the use of blood products. This new understanding and the resulting changes in clinical practice have raised new concerns. In this update, we focus on which patients need damage control resuscitation, current views on the optimal form of damage control resuscitation with blood products, the roles of newer blood products, and appropriate transfusion triggers in the postinjury setting. We will also review the role of new technology in patient assessment, therapy and monitoring.

Transfusion medicine in trauma patients

Injured patients stress the transfusion service with frequent demands for uncrossmatched red cells and plasma, occasional requirements for large amounts of blood products and the need for new and better blood products. Transfusion services stress trauma centers with demands for strict accountability for individual blood component units and adherence to indications in a clinical field where research has been difficult, and guidance opinion-based. New data suggest that the most severely injured patients arrive at the trauma center already coagulopathic and that these patients benefit from prompt, specific, corrective treatment. This research is clarifying trauma system requirements for new blood products and blood-product usage patterns, but the inability to obtain informed consent from severely injured patients remains an obstacle to further research.

Blood product use in trauma resuscitation: plasma deficit versus plasma ratio as predictors of mortality in trauma (CME)

BACKGROUND

Resuscitation of rapidly bleeding trauma patients with units of red blood cells (RBCs) and plasma given in a 1:1 ratio has been associated with improved outcome. However, demonstration of a benefit is confounded by survivor bias, and past work from our group has been unable to demonstrate a benefit.

STUDY DESIGN AND METHODS

We identified 438 adult direct primary trauma admissions at risk for massive transfusion who received 5 or more RBC units in the first 24 hours and had a probability of survival of 0.010 to 0.975. We correlated survival with RBC and plasma use by hour, both as a ratio (units of plasma/units of RBC) and as a plasma deficit (units of RBC - units of plasma) in the group as a whole and among those using 5 to 9 and more than 9 units of RBCs.

RESULTS

Resuscitation was essentially complete in 58.3% by the end of the third hour and 77.9% by the end of the sixth hour. Mortality by hour was significantly associated with worse plasma deficit status in the first 2 hours of resuscitation (p < 0.001 and p < 0.01) but not with plasma ratio. In a subgroup with a Trauma Revised Injury Severity Score of 0.200 to 0.800, early plasma repletion was associated with less blood product use independently of injury severity (p < 0.001).

CONCLUSIONS

1) The efficacy of plasma repletion plays out in the first few hours of resuscitation, 2) plasma deficit may be a more sensitive marker of efficacy in some populations, and 3) early plasma repletion appears to prevent some patients from going on to require massive transfusion.

Hemostatic resuscitation for acute traumatic coagulopathy

Trauma resuscitation paradigms have changed considerably over the last twenty years. Originally, the goal was to normalize a blood pressure as quickly as possible. Large volume crystalloid resuscitation was used to accomplish this. Standard therapy was that any patient with suspected bleeding received a two liter crystalloid bolus as initial therapy. It was often repeated and blood transfusion therapy was used relatively late. Fresh frozen plasma and platelets were also used relatively late, often after patients had received ten units of red cells. Dilutional anemia was relatively common. Patients with large volume blood loss often died from what was termed, "the bloody vicious cycle," of hypothermia, acidosis and coagulopathy.

Glucose elevations and outcome in critically injured trauma patients

Tight glucose control is associated with improved outcome among critically ill trauma patients. Further research is necessary, however, to better elucidate the etiology of this beneficial therapy. Additionally, future randomized trials on this important topic are warranted, as are investigations of emerging technologies that better facilitate tight glucose control in the ICU after trauma.

Endovascular repair of traumatic aortic injuries

Endograft repair has clearly revolutionized the treatment of traumatic aortic injury. Numerous studies, both retrospective and prospective, have documented the advantages with respect to lower mortality and lower paraplegia rates as compared with traditional open repair. Additionally, 2 recent meta-analyses of the published literature both reported significantly lower mortality and paraplegia rates with endovascular repair. These clear improvements, however, come at an increased rate of device-related complications. Currently, newer devices designed to adapt to more acute bends in the proximal thoracic aorta are in the multicenter trial phase. These devices are also expected to be available in a wider range of diameters and lengths, including smaller diameter devices required to treat younger patients. A conformable Gore TAG design is undergoing trials in the United States. Trials of the Talent thoracic device for the treatment of blunt aortic injury are also ongoing. We await the results of the ongoing multicenter trials and expect that with improvements in technology, the vast majority of patients with traumatic aortic injury can be treated without open thoracic aortic surgery. The long-term durability and natural history of thoracic endograft devices, however, are unknown. Continued regular follow-up is recommended, although this can be difficult in this young population of patients. Because follow-up may be ongoing for decades, the need to identify a potential problem has to be weighed against the oncologic risks of repeated radiation exposure.

40-Slice Multidetector CT: Is MRI Still Necessary for Cervical Spine Clearance after Blunt Trauma?

We have recently demonstrated that 16-slice multidetector CT (MDCT) is insufficient for cervical spine (CS) clearance in patients with unreliable examinations after blunt trauma. The purpose of this study was to determine if a negative CS CT using 40-slice MDCT is sufficient for ruling out CS injury in unreliable blunt trauma patients or if MRI remains necessary for definitive clearance. In addition, we sought to elucidate the frequency by which MRI alters treatment in patients with a negative CS CT who have a reliable examination with persistent clinical symptoms. The trauma registry was used to identify all patients with blunt trauma who had a negative CS CT on admission using 40-slice MDCT and a subsequent CS MRI during their hospitalization from July 2006 to July 2007. Two hundred thirteen patients were identified. Overall, 24.4 per cent patients had abnormal MRIs. Fifteen required operative repair; 23 required extended cervical collar; and 14 had collars removed. A total of 8.3 per cent of patients with an unreliable examination and 25.6 per cent of reliable patients had management changed based on MRI findings. Overall, MRI changed clinical practice in 17.8 per cent of all patients. Despite newer 40-slice CT technology, MRI continues to be necessary for CS clearance in patients with unreliable examinations or persistent symptoms.

40-slice multidetector CT: is MRI still necessary for cervical spine clearance after blunt trauma?

We have recently demonstrated that 16-slice multidetector CT (MDCT) is insufficient for cervical spine (CS) clearance in patients with unreliable examinations after blunt trauma. The purpose of this study was to determine if a negative CS CT using 40-slice MDCT is sufficient for ruling out CS injury in unreliable blunt trauma patients or if MRI remains necessary for definitive clearance. In addition, we sought to elucidate the frequency by which MRI alters treatment in patients with a negative CS CT who have a reliable examination with persistent clinical symptoms. The trauma registry was used to identify all patients with blunt trauma who had a negative CS CTon admission using 40-slice MDCT and a subsequent CS MRI during their hospitalization from July 2006 to July 2007. Two hundred thirteen patients were identified. Overall, 24.4 per cent patients had abnormal MRIs. Fifteen required operative repair; 23 required extended cervical collar; and 14 had collars removed. A total of 8.3 per cent of patients with an unreliable examination and 25.6 per cent of reliable patients had management changed based on MRI findings. Overall, MRI changed clinical practice in 17.8 per cent of all patients. Despite newer 40-slice CT technology, MRI continues to be necessary for CS clearance in patients with unreliable examinations or persistent symptoms.

Isolated rollover mechanism does not warrant trauma center evaluation

Significant resources are expended on the assessment of trauma patients who arrive at the trauma center based solely on mechanism of injury. We hypothesized that rollover motor vehicle crashes (ROMVC) are not an independent predictor for trauma center care. All patients seen between January 1, 2001, and December 31, 2005, involved in a ROMVC, were reviewed. Patients with any confounding factors were removed, leaving those transported to the trauma center based on mechanism only. Five hundred sixty-nine patients were transported to our center for the mechanism of ROMVC. Of the 569 patients, 369 (65%) were evaluated and discharged with minimal Injury Severity Score and regional Abbreviated Injury Scale scores. Of the remaining 200 (35%) patients admitted, 130 required surgery, predominantly for closed extremity and facial fractures. Six patients required immediate surgery for life-threatening injuries: 3 splenectomies, 1 subdural evacuation, and 2 vascular repairs (1.1%). Of the remaining 123 (4.2%) patients requiring surgery, 24 required urgent surgery (2 craniotomies, 9 laparotomies, and 13 spinal fixations). None of the patients with spinal injury had neurologic deficit. Eight patients were admitted to the intensive care unit for neurologic monitoring (1.4%). Only 6.7 per cent benefited from initial Trauma Triage Criteria. Therefore, ROMVC is not an independent predictor of the need for trauma center evaluation or admission. The majority of these patients could be safely evaluated and treated at nontrauma centers or transferred later.

Isolated Rollover Mechanism Does Not Warrant Trauma Center Evaluation

Significant resources are expended on the assessment of trauma patients who arrive at the trauma center based solely on mechanism of injury. We hypothesized that rollover motor vehicle crashes (ROMVC) are not an independent predictor for trauma center care. All patients seen between January 1, 2001, and December 31, 2005, involved in a ROMVC, were reviewed. Patients with any confounding factors were removed, leaving those transported to the trauma center based on mechanism only. Five hundred sixty-nine patients were transported to our center for the mechanism of ROMVC. Of the 569 patients, 369 (65%) were evaluated and discharged with minimal Injury Severity Score and regional Abbreviated Injury Scale scores. Of the remaining 200 (35%) patients admitted, 130 required surgery, predominantly for closed extremity and facial fractures. Six patients required immediate surgery for life-threatening injuries: 3 splenectomies, 1 subdural evacuation, and 2 vascular repairs (1.1%). Of the remaining 123 (4.2%) patients requiring surgery, 24 required urgent surgery (2 craniotomies, 9 laparotomies, and 13 spinal fixations). None of the patients with spinal injury had neurologic deficit. Eight patients were admitted to the intensive care unit for neurologic monitoring (1.4%). Only 6.7 per cent benefited from initial Trauma Triage Criteria. Therefore, ROMVC is not an independent predictor of the need for trauma center evaluation or admission. The majority of these patients could be safely evaluated and treated at nontrauma centers or transferred later.