Physiologic parameters and radiologic findings can predict pulmonary complications and guide management in traumatic rib fractures

BACKGROUND

Traumatic rib fracture is associated with a high morbidity rate and identifying patients at risk of developing pulmonary complications (PC) can guide management and potentially decrease unnecessary intensive care admissions. Therefore, we sought to assess and compare the utility of a physiologic parameter, vital capacity (VC), with the admission radiologic findings (RibScore) in predicting PC in patients with rib fractures.

METHODS

This is a single-center retrospective review (2015-2018) of all adult (≥18 years) patients admitted to a Level I trauma center with traumatic rib fracture. Exclusion criteria included no CT scan and absence of VC within 48 h of admission. The cohort was stratified into two groups based on presence or absence of PC (pneumonia, unplanned intubation, unplanned transfer to the intensive care unit for a respiratory concern, or the need for a tracheostomy). Multivariable logistic regression models were constructed to identify predictors of PC.

RESULTS

A total of 654 patients met the inclusion criteria of whom 70 % were males. The median age was 51 years and fall (48 %) was the most common type of injury. A total of 36 patients (5.5 %) developed a pulmonary complication. These patients were more likely to be older, had a higher ISS, and were more likely to require a tube thoracostomy placement. On multivariable logistic regression, first VC ≤30 % (AOR: 4.29), day 1 VC ≤30 % (AOR: 3.61), day 2 VC ≤30 % (AOR: 5.54), Δ(Day2-Day1 VC) (AOR: 0.96), and RibScore ≥2 (AOR: 3.19) were significantly associated with PC. On discrimination analysis, day 2 VC had the highest area under the receiver operating characteristic curve (AuROC), 0.81, and was superior to first VC and day 1 VC in predicting PC. There was no statistically significant difference in predicting PC between day 2 VC and RibScore. On multivariable analysis, first VC ≤30 %, day 1 VC ≤30 %, day 2 VC ≤30 %, and admission RibScore ≥2 were associated with prolonged hospital and ICU LOS.

CONCLUSION

VC and RibScore emerged as independent predictors of PC. However, VC was not found to be superior to RibScore in predicting PC. Further prospective research is warranted to validate the findings of this study.

Early venous thromboembolism chemoprophylaxis in traumatic brain injury requiring neurosurgical intervention: Safe and effective

BACKGROUND

Traumatic brain injury patients who require neurosurgical intervention are at the highest risk of worsening intracranial hemorrhage. This subgroup of patients has frequently been excluded from prior research regarding the timing of venous thromboembolism chemoprophylaxis. This study aims to assess the efficacy and safety of early venous thromboembolism chemoprophylaxis in patients with traumatic brain injuries requiring neurosurgical interventions.

METHODS

This is a single-center retrospective review (2016-2020) of traumatic brain injury patients requiring neurosurgical intervention admitted to a level I trauma center. Interventions included intracranial pressure monitoring, subdural drain, external ventricular drain, craniotomy, and craniectomy. Exclusion criteria included neurosurgical intervention after chemoprophylaxis initiation, death within 5 days of admission, and absence of chemoprophylaxis. The total population was stratified into Early (≤72 hours of intervention) versus Late (>72 hours after intervention) chemoprophylaxis initiation.

RESULTS

A total of 351 patients met the inclusion criteria, of whom 204 (58%) had early chemoprophylaxis initiation. Overall, there were no significant differences in baseline and admission characteristics between cohorts. The Early chemoprophylaxis cohort had a statistically significant lower venous thromboembolism rate (5% vs 13%, P < .001) with no increased risk of worsening intracranial hemorrhage (10% vs 13%, P = .44) or neurosurgical reintervention (8% vs 10%, P = .7). On subgroup analysis, a total of 169 patients required either a craniotomy or a craniectomy before chemoprophylaxis. The Early chemoprophylaxis cohort had statistically significant lower venous thromboembolism rates (2% vs 11%, P < .001) with no increase in intracranial hemorrhage (8% vs 11%, P = .6) or repeat neurosurgical intervention (8% vs 10%, P = .77).

CONCLUSION

Venous thromboembolism prophylaxis initiation within 72 hours of neurosurgical intervention is safe and effective. Further prospective research is warranted to validate the results of this study.

Thoracic Cavity Irrigation Prevents Retained Hemothorax and Decreases Surgical Intervention in Trauma Patients

INTRODUCTION

Retained hemothorax (HTX) is a common complication following thoracic trauma. Small studies demonstrate the benefit of thoracic cavity irrigation at the time of tube thoracostomy for the prevention of retained HTX. We sought to assess the effectiveness of chest irrigation in preventing retained HTX leading to a secondary surgical intervention.

METHODS

We performed a single-center retrospective study from 2017-2021 at a Level I trauma center comparing bedside thoracic cavity irrigation via tube thoracostomy (TT) versus no irrigation. Using the trauma registry, patients with traumatic HTX were identified. Exclusion criteria were TT placement at an outside hospital, no TT within 24 hours of admission, thoracotomy or video-assisted thoracoscopic surgery (VATS) prior to or within 6 hours after TT placement, VATS as part of rib fixation or diaphragmatic repair, and death within 96 hours of admission. Bivariate and multivariable analyses were conducted.

RESULTS

A total of 370 patients met the inclusion criteria, of whom 225 (61%) were irrigated. Patients who were irrigated were more likely to suffer a penetrating injury (41% vs 30%, p = 0.03) and less likely to have a flail chest (10% vs 21%, p = 0.01) (Table 1). On bivariate analysis, irrigation was associated with lower rates of VATS (6% vs 19%, p < 0.001) and retained HTX (10% vs 21%, p < 0.001) (Figure 1). The irrigated cohort had a shorter TT duration (4 vs 6 days, p < 0.001) and hospital length of stay (LOS) (7 vs 9 days, p = 0.04). On multivariable analysis, thoracic cavity irrigation had lower odds of VATS (aOR: 0.37, 95%CI: 0.30-0.54), retained HTX (aOR: 0.42, 95%CI: 0.25-0.74), and a shorter TT duration (β: -1.58, 95%CI: -2.52, -0.75).

CONCLUSION

Our 5-year experience with thoracic irrigation confirms findings from smaller studies that irrigation prevents retained HTX and decreases the need for surgical intervention.

LEVEL OF EVIDENCE

Level III, Therapeutic/Care Management.

A Collaborative Multidisciplinary Trauma Program Improvement Team Improves VTE Chemoprophylaxis Guideline Compliance In Non-Operative Stable TBI

BACKGROUND

Delays in initiating venous thromboembolism (VTE) prophylaxis in patients suffering from traumatic brain injury (TBI) persist despite guidelines recommending early initiation. We hypothesized that the expansion of a Trauma Program Performance Improvement (PI) team will improve compliance of early (24-48 hour) initiation of VTE prophylaxis and will decrease VTE events in TBI patients.

METHODS

We performed a single-center retrospective review of all TBI patients admitted to a Level I trauma center before (2015-2016,) and after (2019-2020,) the expansion of the Trauma Performance Improvement and Patient Safety (PIPS) team and the creation of trauma process and outcome dashboards. Exclusion criteria included discharge or death within 48 hours of admission, expanding intracranial hemorrhage on CT scan, and a neurosurgical intervention (craniotomy, pressure monitor, or drains) prior to chemoprophylaxis initiation.

RESULTS

A total of 1,112 patients met the inclusion criteria, of which 54% (n = 604) were admitted after Trauma PIPS expansion. Following the addition of a dedicated PIPS nurse in the trauma program and creation of process dashboards, the time from stable CT to VTE prophylaxis initiation decreased (52 hours to 35 hours; p < 0.001) and more patients received chemoprophylaxis at 24-48 hours (59% from 36%, p < 0.001) after stable head CT. There was no significant difference in time from first head CT to stable CT (9 vs 9 hours; p = 0.15). The Contemporary group had a lower rate of VTE events (1% vs 4%; p < 0.001) with no increase in bleeding events (2% vs 2%; p = 0.97). On multivariable analysis, being in the Early cohort was an independent predictor of VTE events (aOR: 3.74; 95%CI: 1.45-6.16).

CONCLUSION

A collaborative multidisciplinary Trauma PIPS team improves guideline compliance. Initiation of VTE chemoprophylaxis within 24-48 hours of stable head CT is safe and effective.

LEVEL OF EVIDENCE

Level III, Therapeutic/Care Management.

Open versus endovascular repair of penetrating non-aortic arterial injuries: A systematic review and meta analysis

BACKGROUND

Non-aortic arterial injuries are common and are associated with high morbidity and mortality. Historically, open surgical repair (OSR) was the conventional method of repair. With recent advancements in minimally invasive techniques, endovascular repair (ER) has gained popularity. We sought to compare outcomes in patients undergoing endovascular and open repairs of traumatic non-aortic penetrating arterial injuries.

METHODS

A systematic review and meta-analysis was conducted using MEDLINE (OVID), Web of Science, Cochrane Library, and Scopus Database from January 1st, 1990, to March 20th, 2023. Titles and abstracts were screened, followed by full text review. Articles assessing clinically important outcomes between OSR and ER in penetrating arterial injuries were included. Exclusion criteria included blunt injuries, aortic injuries, pediatric populations, review articles, and non-English articles. Odds ratios (OR) and Cohen's d ratios were used to quantify differences in morbidity and mortality.

RESULTS

A total of 3770 articles were identified, of which 8 met inclusion criteria and were included in the review. The articles comprised a total of 8369 patients of whom 90 % were male with a median age of 28 years. 85 % of patients were treated with OSR while 15 % underwent ER. With regards to injury characteristics, those who underwent ER were less likely to present with concurrent venous injuries (OR: 0.41; 95 %CI: 0.18, 0.94; p = 0.03). Regarding hospital outcomes, patients who underwent ER had a lower likelihood of in-hospital or 30-day mortality (OR: 0.72; 95 %CI: 0.55, 0.95; p = 0.02) and compartment syndrome (OR: 0.29, 95 %CI: 0.12, 0.71; p = 0.007). The overall risk of bias was moderate.

CONCLUSION

Endovascular repair of non-aortic penetrating arterial injuries is increasingly common, however open repair remains the most common approach. Compared to ER, OSR was associated with higher odds of compartment syndrome and mortality. Further prospective research is warranted to determine the patient populations and injury patterns that most significantly benefit from an endovascular approach.

LEVEL OF EVIDENCE

Level III, Systematic Reviews & Meta-Analyses.

A western trauma association multicenter comparison of mesh versus non-mesh repair of blunt traumatic abdominal wall hernias

BACKGROUND

Blunt traumatic abdominal wall hernias (TAWH) occur in <1 % of trauma patients. Optimal repair techniques, such as mesh reinforcement, have not been studied in detail. We hypothesize that mesh use will be associated with increased surgical site infections (SSI) and not improve hernia recurrence.

MATERIALS AND METHODS

A secondary analysis of the Western Trauma Association blunt TAWH multicenter study was performed. Patients who underwent TAWH repair during initial hospitalization (1/2012-12/2018) were included. Mesh repair patients were compared to primary repair patients (non-mesh). A logistic regression was conducted to assess risk factors for SSI.

RESULTS

157 patients underwent TAWH repair during index hospitalization with 51 (32.5 %) having mesh repair: 24 (45.3 %) synthetic and 29 (54.7 %) biologic. Mesh patients were more commonly smokers (43.1 % vs. 22.9 %, p = 0.016) and had a larger defect size (10 vs. 6 cm, p = 0.003). Mesh patients had a higher rate of SSI (25.5 % vs. 9.5 %, p = 0.016) compared to non-mesh patients, but a similar rate of recurrence (13.7 % vs. 10.5%, p = 0.742), hospital length of stay (LOS), and mortality. Mesh use (OR 3.66) and higher ISS (OR 1.06) were significant risk factors for SSI in a multivariable model.

CONCLUSION

Mesh was used more frequently in flank TAWH and those with a larger defect size. Mesh use was associated with a higher incidence and risk of SSI but did not reduce the risk of hernia recurrence. When repairing TAWH mesh should be employed judiciously, and prospective randomized studies are needed to identify clear indications for mesh use in TAWH.

A Prescribing Guideline Decreases Postoperative Opioid Prescribing in Emergency General Surgery

INTRODUCTION

Patients prescribed higher opioid dosages have a higher risk of persistent opioid use, overdose, and death. There is a lack of standardization for opioid prescribing for acute surgical pain in emergency general surgery (EGS) patients. We hypothesized that implementing a guideline to standardize opioid prescribing would be associated with a decrease in prescribing at hospital discharge for EGS patients without increasing additional postdischarge refills.

METHODS

This was a quasi-experimental study evaluating opioid prescribing by EGS providers before and after the implementation of a prescribing guideline. Patients were assigned to preguideline and postguideline groups based on admission date surrounding the implementation of the guideline. The primary outcome was the proportion of patients receiving an opioid prescription for ≥50 Morphine Milligram Equivalents (MME) per day on hospital discharge.

RESULTS

There were 227 patients in the preguideline group and 226 patients in the postguideline group. After guideline implementation, median total MME prescribed decreased from 113 (interquartile range = 75) to 75 (interquartile range = 75, P = 0.03). The proportion of patients receiving a prescription for daily MME ≥50 also decreased from 75% to 25% (P ≤0.01). There were no increases in requested refills (17% versus 16%, P = 0.72) or received refills (14% versus 14%, P = 0.98). Guideline compliance ranged from 75% in ventral hernia repair patients to 94% in laparoscopic cholecystectomy patients.

CONCLUSIONS

A departmental guideline to standardize postoperative opioid prescriptions was associated with a decrease in the amount of MMEs prescribed to EGS patients without an increase in requested or received refills.

The efficacy of various Enoxaparin dosing regimens in general surgery patients: A systematic review

BACKGROUND

Patients undergoing surgical procedures are at an increased risk of venous thromboembolism events. A fixed Enoxaparin dosing regimen is the standard of care for chemoprophylaxis in most institutions; however, breakthrough venous thromboembolism events are still reported. We aimed to systematically review the literature to determine the ability of various Enoxaparin dosing regimens to achieve adequate prophylactic anti-Xa levels for venous thromboembolism prevention in hospitalized general surgery patients. Additionally, we aimed to assess the correlation between subprophylactic anti-Xa levels and the development of clinically significant venous thromboembolism events.

METHODS

A systematic review was conducted using major databases from January 1, 1993, to February 17, 2023. Two independent researchers screened titles and abstracts, followed by a full-text review. Articles were included if Enoxaparin dosing regimens were evaluated by anti-Xa levels. Exclusion criteria included systematic reviews, pediatric population, nongeneral surgery (defined as trauma, orthopedics, plastics, and neurosurgery), and non-Enoxaparin chemoprophylaxis. The primary outcome was peak Anti-Xa level measured at steady state concentration. The risk of bias was assessed using the Risk of Bias in Nonrandomized studies-of Intervention tool.

RESULTS

A total of 6,760 articles were extracted, of which 19 were included in the scoping review. Nine studies included bariatric patients, whereas 5 studies explored abdominal surgical oncology patients. Three studies assessed thoracic surgery patients, and 2 studies included patients undergoing "general surgery" procedures. A total of 1,502 patients were included. The mean age was 47 years, and 38% were males. The percentages of patients reaching adequate prophylactic anti-Xa levels were 39%, 61%, 15%, 50%, and 78% across the 40 mg daily, 40 mg twice daily, 30 mg twice daily, and weight-tiered, and body mass index-based groups, respectively. The overall risk of bias was low to moderate.

CONCLUSION

Fixed Enoxaparin dosing regimens are not correlated with adequate anti-Xa levels in general surgery patients. Additional research is warranted to assess the efficacy of dosing regimens based on novel physiologic parameters (such as estimated blood volume).

Risk factors for recurrence in blunt traumatic abdominal wall hernias: A secondary analysis of a Western Trauma association multicenter study

BACKGROUND

Few studies have investigated risk factors for recurrence of blunt traumatic abdominal wall hernias (TAWH).

METHODS

Twenty trauma centers identified repaired TAWH from January 2012 to December 2018. Logistic regression was used to investigate risk factors for recurrence.

RESULTS

TAWH were repaired in 175 patients with 21 (12.0%) known recurrences. No difference was found in location, defect size, or median time to repair between the recurrence and non-recurrence groups. Mesh use was not protective of recurrence. Female sex, injury severity score (ISS), emergency laparotomy (EL), and bowel resection were associated with hernia recurrence. Bowel resection remained significant in a multivariable model.

CONCLUSION

Female sex, ISS, EL, and bowel resection were identified as risk factors for hernia recurrence. Mesh use and time to repair were not associated with recurrence. Surgeons should be mindful of these risk factors but could attempt acute repair in the setting of appropriate physiologic parameters.

Trauma surgeon-performed peripheral arterial repairs are associated with equivalent outcomes when compared with vascular surgeons

BACKGROUND

Civilian extremity trauma with vascular injury carries a significant risk of morbidity, limb loss, and mortality. We aim to describe the trends in extremity vascular injury repair and compare outcomes between trauma and vascular surgeons.

METHODS

We performed a single-center retrospective review of patients 18 years or older with extremity vascular injury requiring surgical intervention between January 2009 and December 2019. Demographics, injury characteristics, operative course, and hospital course were analyzed. Descriptive statistics were used to examine management trends, and outcomes were compared for arterial repairs. Multivariate regression was used to evaluate surgeon specialty as a predictor of complications, readmission, vascular outcomes, and mortality.

RESULTS

A total of 231 patients met our inclusion criteria; 80% were male with a median age of 29 years. The femoral vessels were most commonly injured (39.4%), followed by the popliteal vessels (26.8%). Trauma surgeons performed the majority of femoral artery repairs (82%), while vascular surgeons repaired the majority of popliteal artery injuries (84%). Both had a similar share of brachial artery repairs (36% vs. 39%, respectively). There were no differences in complications, readmission, vascular outcomes, and mortality. Median time from arrival to operating room was significantly shorter for trauma surgeons. There was a significant downward trend between 2009 and 2017 in the proportion of total and femoral vascular procedures performed by trauma surgeons. On multivariate regression, surgical specialty was not a significant predictor of need for vascular reintervention, prophylactic or delayed fasciotomies, postoperative complications, or readmissions.

CONCLUSION

Traumas surgeons arrived quicker to the operating and had no difference in short-term clinical outcomes of brachial and femoral artery repairs compared with patients treated by vascular surgeons. Over the last decade, there has been a significant decline in the number of open vascular repairs done by trauma surgeons.

LEVEL OF EVIDENCE

Therapeutic/Care Management, Level IV.

Management of blunt traumatic abdominal wall hernias: A Western Trauma Association multicenter study

BACKGROUND

Blunt traumatic abdominal wall hernias (TAWH) occur in approximately 15,000 patients per year. Limited data are available to guide the timing of surgical intervention or the feasibility of nonoperative management.

METHODS

A retrospective study of patients presenting with blunt TAWH from January 2012 through December 2018 was conducted. Patient demographic, surgical, and outcomes data were collected from 20 institutions through the Western Trauma Association Multicenter Trials Committee.

RESULTS

Two hundred and eighty-one patients with TAWH were identified. One hundred and seventy-six (62.6%) patients underwent operative hernia repair, and 105 (37.4%) patients underwent nonoperative management. Of those undergoing surgical intervention, 157 (89.3%) were repaired during the index hospitalization, and 19 (10.7%) underwent delayed repair. Bowel injury was identified in 95 (33.8%) patients with the majority occurring with rectus and flank hernias (82.1%) as compared with lumbar hernias (15.8%). Overall hernia recurrence rate was 12.0% (n = 21). Nonoperative patients had a higher Injury Severity Score (24.4 vs. 19.4, p = 0.010), head Abbreviated Injury Scale score (1.1 vs. 0.6, p = 0.006), and mortality rate (11.4% vs. 4.0%, p = 0.031). Patients who underwent late repair had lower rates of primary fascial repair (46.4% vs. 77.1%, p = 0.012) and higher rates of mesh use (78.9% vs. 32.5%, p < 0.001). Recurrence rate was not statistically different between the late and early repair groups (15.8% vs. 11.5%, p = 0.869).

CONCLUSION

This report is the largest series and first multicenter study to investigate TAWHs. Bowel injury was identified in over 30% of TAWH cases indicating a significant need for immediate laparotomy. In other cases, operative management may be deferred in specific patients with other life-threatening injuries, or in stable patients with concern for bowel injury. Hernia recurrence was not different between the late and early repair groups.

LEVEL OF EVIDENCE

Therapeutic/care management, Level IV.

Field-Triage, Hospital-Triage and Triage-Assessment: A Literature Review of the Current Phases of Adult Trauma Triage

ABSTRACT

Despite major improvements in the United States trauma system over the past two decades, prehospital trauma triage is a significant challenge. Undertriage is associated with increased mortality, and overtriage results in significant resource overuse. The American College of Surgeons Committee on Trauma benchmarks for undertriage and overtriage are not being met. Many barriers to appropriate field triage exist, including lack of a formal definition for major trauma, absence of a simple and widely applicable triage mode, and emergency medical service adherence to triage protocols. Modern trauma triage systems should ideally be based on the need for intervention rather than injury severity. Future studies should focus on identifying the ideal definition for major trauma and creating triage models that can be easily deployed. This narrative review article presents challenges and potential solutions for prehospital trauma triage.

Validation of the Injured Trauma Survivor Screen: An American Association for the Surgery of Trauma multi-institutional trial

BACKGROUND

Psychological distress is common following a traumatic injury event. The Injured Trauma Survivor Screen (ITSS) was developed at a level 1 trauma center to assess for posttraumatic stress disorder (PTSD) and major depressive episode (MDE) following admission for a traumatic injury. The ITSS sensitivity and specificity were analyzed 1 to 3 and 6 to 9 months postinjury to test the validity across trauma centers.

METHOD

Four level 1 trauma centers from the East, Midwest, South, and West in the United States recruited 375 eligible adult inpatients (excluded participants included those with moderate or severe traumatic brain injury, whose injury was self-inflicted, were noncommunicative, or were non-English speaking). Baseline sample (White/Caucasian, 63.2%; male, 62.4%; mean (SD) age, 45 (17.11) years; injured by motor vehicle collision, 42.4%) measurements were conducted during index hospitalization. At first follow-up, 69.6% (n = 261) were retained; at second follow-up, 61.3% (n = 230) were retained. Measurements included the ITSS, PTSD Checklist for DSM-5, Center for Epidemiologic Studies Depression Scale-Revised, and Clinician-Administered PTSD Scaled for DSM 5.

RESULTS

At follow-up 1, the ITSS PTSD subscale had a sensitivity of 75% and specificity of 78.8%, and the MDE subscale had a sensitivity of 80.4% and specificity of 65.6%. At follow-up 2, the PTSD subscale had a sensitivity of 72.7% and specificity of 83.1%, and the MDE subscale had a sensitivity of 76.1% and specificity of 68.3%. A combined risk group using two symptom based measures administered at baseline produced increased specificity.

CONCLUSION

The nine-item ITSS continues to be an efficient and effective risk screen for PTSD and MDE following traumatic injury requiring hospitalization. This multi-institutional validation study creates a solid foundation for further exploration of the generalizability of this screen's psychometric properties in distinct populations.

LEVEL OF EVIDENCE

Prognostic study, level III.

The Role of Computed Tomography in the Diagnosis of Necrotizing Soft Tissue Infections

BACKGROUND

The exact role of IV contrast-enhanced computed tomography (CT) in the diagnosis of necrotizing soft tissue infections (NSTIs) has not yet been established. We aimed to explore the role of CT in patients with clinical suspicion of NSTI and assess its sensitivity and specificity for NSTI.

METHODS

The medical records of patients admitted between 2009 and 2016, who received IV contrast-enhanced CT to rule out NSTI, were reviewed. CT was considered positive in case of: (a) gas in soft tissues, (b) multiple fluid collections, (c) absence or heterogeneity of tissue enhancement by the IV contrast, and (d) significant inflammatory changes under the fascia. NSTI was confirmed only by the presence of necrotic tissue during surgical exploration. NSTI was considered absent if surgical exploration failed to identify necrosis, or if the patient was successfully treated non-operatively.

RESULTS

Of the 184 patients, 17 had a positive CT and hence underwent surgical exploration with NSTI being confirmed in 13 of them (76%). Of the 167 patients that had a negative CT, 38 (23%) underwent surgical exploration due to the high clinical suspicion for NSTI and were all found to have non-necrotizing infections; the remaining 129 (77%) were managed non-operatively with successful resolution of symptoms. The sensitivity of CT in identifying NSTI was 100%, the specificity 98%, the positive predictive value 76%, and the negative predictive value 100%.

CONCLUSIONS

A negative IV contrast-enhanced CT scan can reliably rule out the need for surgical intervention in patients with initial suspicion of NSTI.

Prospective evaluation of a continuous infusion vancomycin dosing nomogram in critically ill patients undergoing continuous venovenous haemofiltration

Objectives

The most optimal method of attaining therapeutic vancomycin concentrations during continuous venovenous haemofiltration (CVVH) remains unclear. Studies have shown continuous infusion vancomycin (CIV) achieves target concentrations more rapidly and consistently when compared with intermittent infusion. Positive correlations between CVVH intensity and vancomycin clearance (CLvanc) have been noted. This study is the first to evaluate a CIV regimen in patients undergoing CVVH that incorporates weight-based CVVH intensity (mL/kg/h) into the dosing nomogram.

Methods

This was a prospective, observational study of patients undergoing CVVH and receiving CIV based on the nomogram. The primary outcome was achievement of a therapeutic vancomycin concentration (15-25 mg/L) at 24 h. Secondary outcomes included the achievement of therapeutic concentrations at 48 and 72 h.

Results

The nomogram was analysed in 52 critically ill adults. Vancomycin concentrations were therapeutic in 43/52 patients (82.7%) at 24 h. Of the nine patients who were not therapeutic at 24 h, seven were supratherapeutic and two were subtherapeutic. The mean (SD) concentration was 20.1 (4.2)  mg/L at 24 h, 20.7 (3.7) mg/L at 48 h and 21.9 (3.5)  mg/L at 72 h. Patients with CVVH intensity >20 mL/kg/h experienced higher CLvanc at 24 h compared with patients with CVVH intensity <20 mL/kg/h (3.1 versus 2.6 L/h; P = 0.013).

Conclusions

By incorporating CVVH intensity into the CIV dosing nomogram, the majority of patients achieved therapeutic concentrations at 24 h and maintained them within range at 48 and 72 h. Additional studies are required to validate this nomogram before widespread implementation may be considered.

Effects of a New Hospital-Wide Surgical Consultation Protocol in Patients with Clostridium difficile Colitis

BACKGROUND

Fulminant Clostridium difficile colitis (fCDC) occurs in 2%-8% of patients with CDC and carries a high death rate. Prompt operation may reduce death. Our aim was to determine whether a standardized hospital-wide protocol for surgical referral in CDC would result in earlier surgical consultation, earlier identification of patients who could benefit from surgical therapy, and reduced deaths from fCDC.

METHODS

A multidisciplinary team developed consensus criteria for surgical consultation. Compliance was evaluated by prospective review of all inpatient CDC cases. Outcomes of the prospective cohort (POST) were compared to an historic control group (PRE).

RESULTS

From November 1, 2010 to October 31, 2012, we identified 1,106 inpatients with CDC; 339 patients matched the consultation criteria, of whom 213 received a surgical consultation, resulting in an overall compliance rate of 62.8%. All those with fCDC received a surgical consultation, with a median time to surgical referral of three hours. Of 46 patients with fCDC, 11 (23.9%) died, compared with 34.8% in the historical control group (p = 0.15). The death rate was 14.7% in the POST group, when excluding patients with limitations of care and those transferred to our institution in a fulminant state. There was a shorter interval between admission and surgical intervention for those who required operation in the POST group-three (1-11) days versus 1.5 (0-3) days, respectively, in the PRE and POST groups (p = 0.018), and a shorter adjusted median hospital length of stay (adjusted difference 9.0, 95% CI 2.2-12.3, p = 0.007) Conclusions: A hospital-wide protocol with established criteria for surgical consultation resulted in faster intervention and a shorter adjusted median hospital length of stay. The overall death rate for fCDC patients without limitations of life-sustaining treatment who presented to our emergency department or in whom fCDC developed while they were admitted to our hospital was 14.7%.

Surgery Clerkship Evaluations Are Insufficient for Clinical Skills Appraisal: The Value of a Medical Student Surgical Objective Structured Clinical Examination

OBJECTIVE

Optimal methods for medical student assessment in surgery remain elusive. Faculty- and housestaff-written evaluations constitute the chief means of student assessment in medical education. However, numerous studies show that this approach has poor specificity and a high degree of subjectivity. We hypothesized that an objective structured clinical examination (OSCE) in the surgery clerkship would provide additional data on student performance that would confirm or augment other measures of assessment.

DESIGN

We retrospectively reviewed data from OSCEs, National Board of Medical Examiners shelf examinations, oral presentations, and written evaluations for 51 third-year Harvard Medical School students rotating in surgery at Massachusetts General Hospital from 2014 to 2015. We expressed correlations between numeric variables in Pearson coefficients, stratified differences between rater groups by one-way analysis of variance, and compared percentages with 2-sample t-tests. We examined commentary from both OSCE and clinical written evaluations through textual analysis and summarized these results in percentages.

RESULTS

OSCE scores and clinical evaluation scores correlated poorly with each other, as well as with shelf examination scores and oral presentation grades. Textual analysis of clinical evaluation comments revealed a heavy emphasis on motivational factors and praise, whereas OSCE written comments focused on cognitive processes, patient management, and methods to improve performance.

CONCLUSIONS

In this single-center study, an OSCE provided clinical skills data that were not captured elsewhere in the surgery clerkship. Textual analysis of faculty evaluations reflected an emphasis on interpersonal skills, rather than appraisal of clinical acumen. These findings suggest complementary roles of faculty evaluations and OSCEs in medical student assessment.

Protocol Standards for Reporting Video Data in Academic Journals

Editors of biomedical journals have estimated that a majority (40%-90%) of studies published in scientific journals cannot be replicated, even though an inherent principle of publication is that others should be able to replicate and build on published claims. Each journal sets its own protocols for establishing "quality" in articles, yet over the past 50 years, few journals in any field--especially medical education--have specified protocols for reporting the use of video data in research. The authors found that technical and industry-driven aspects of video recording, as well as a lack of standardization and reporting requirements by research journals, have led to major limitations in the ability to assess or reproduce video data used in research. Specific variables in the videotaping process (e.g., camera angle), which can be changed or be modified, affect the quality of recorded data, leading to major reporting errors and, in turn, unreliable conclusions. As more data are now in the form of digital videos, the historical lack of reporting standards makes it increasingly difficult to accurately replicate medical educational studies. Reproducibility is especially important as the medical education community considers setting national high-stakes standards in medicine and surgery based on video data. The authors of this Perspective provide basic protocol standards for investigators and journals using video data in research publications so as to allow for reproducibility.

Antibiotic Regimen after a Total Abdominal Colectomy with Ileostomy for Fulminant Clostridium difficile Colitis: A Multi-Institutional Study

BACKGROUND

Fulminant Clostridium difficile colitis (fCDC) is a highly lethal disease with mortality rates ranging between 12% and 80%. Although often these patients require a total abdominal colectomy (TAC) with ileostomy, there is no established management protocol for post-operative antibiotics. In this study we aim to make some recommendations for post-operative antibiotic usage, while describing the practice across different institutions.

METHODS

Multi-institutional retrospective case series including fCDC patients who underwent a TAC between January 1, 2007, and June 30, 2012. We first analyzed the complete cohort and consecutively performed a survivor analysis, comparing different antibiotic regimens. Additionally we stratified by time interval (antibiotics for ≤7 d, or ≥8 d). Primary outcome was in-hospital mortality. Additional secondary outcomes included hospital length of stay (HLOS), ICU LOS, number of ventilator-free days, and occurrence of intra-abdominal complications (proctitis, abscess, sepsis, etc.).

RESULTS

A total of 100 fCDC patients that underwent a TAC were included across five institutions. Four different antibiotic regimens were compared; A (metronidazole IV+vancomycin PO), B (metronidazole IV), C (metronidazole IV+vanco PO and PR), and D (metronidazole IV+vancomycin PR). The combination of IV metronidazole with or without PO vancomycin showed superior outcomes in terms of a shorter ICU length of stay and more ventilator-free days. However, when comparing metronidazole alone vs. metronidazole and any combination of vancomycin, no significant differences were found. Neither the addition of vancomycin enema, nor the time interval changed outcomes.

CONCLUSION

Patients, after a TAC for fCDC, may be placed on either IV metronidazole or PO vancomycin depending upon local antibiograms, and proctitis may be treated with the addition of a vancomycin enema (PR). There was no data to support routine treatment of more than 7 d.

The clinical significance of isolated loss of lordosis on cervical spine computed tomography in blunt trauma patients: a prospective evaluation of 1,007 patients

BACKGROUND

A negative computed tomographic (CT) scan may be used to rule out cervical spine (c-spine) injury after trauma. Loss of lordosis (LOL) is frequently found as the only CT abnormality. We investigated whether LOL should preclude c-spine clearance.

METHODS

All adult trauma patients with isolated LOL at our Level I trauma center (February 1, 2011 to May 31, 2012) were prospectively evaluated. The primary outcome was clinically significant injury on magnetic resonance imaging (MRI), flexion-extension views, and/or repeat physical examination.

RESULTS

Of 3,333 patients (40 ± 17 years, 60% men) with a c-spine CT, 1,007 (30%) had isolated LOL. Among 841 patients with a Glasgow Coma Scale score of 15, no abnormalities were found on MRI, flexion-extension views, and/or repeat examinations, and all collars were removed. Among 166 patients with Glasgow Coma Scale less than 15, 3 (.3%) had minor abnormal MRI findings but no clinically significant injury.

CONCLUSION

Isolated LOL on c-spine CT is not associated with a clinically significant injury and should not preclude c-spine clearance.

Is CT Angiography of the Head Useful in the Management of Traumatic Brain Injury?

BACKGROUND

Computed tomography angiography (CTA) has been increasingly used in traumatic brain injury (TBI) patients to uncover vascular lesions that might have preceded the trauma and caused the bleed. This study aims to evaluate the usefulness of head CTA in the initial care of blunt TBI patients.

STUDY DESIGN

We conducted a retrospective case-control analysis of adult TBI patients, admitted to our Level I trauma center from January 1, 2012 to December 31, 2012. The patients were grouped as those with and without a CTA of the head. The primary outcomes included a change in management after the findings of head CTA and secondary outcomes included rate of admission to the ICU, ICU length of stay, hospital length of stay, discharge disposition, and mortality.

RESULTS

Six hundred adult patients had blunt TBI and underwent head CT as a part of their evaluation. Of these 600 patients, 132 (22%) underwent head CTA in addition to CT. Only one patient had altered management after the CTA results; the patient had a diagnostic angiogram that was negative. Ninety-eight patients did not have any additional findings on CTA. Of the remaining 33 patients with additional CTA findings, 12 had incidental vascular malformations, which showed no acute pathology and were not related to the injury. In the matched comparisons, patients with CTA had a longer hospital stay, higher rate of ICU admission, and longer ICU stay. There was no significant difference in mortality and discharge disposition between the 2 groups.

CONCLUSIONS

Head CTA is commonly used after blunt TBI but does not alter management and should be abandoned in the absence of clear indications.

Appendectomy and Pregnancy: Gestational Age Does Not Affect the Position of the Incision

The position of the base of the appendix during advancing gestational age is based on inadequate data. Therefore, the proper location for an appendectomy incision during pregnancy is highly unclear. This study investigated the location of the appendix during pregnancy to determine the optimal location for an incision in pregnant patients with appendicitis relative to McBurney's point. Magnetic resonance images (MRIs) were reviewed independently by two fellowship-trained abdominal MRI radiologists blinded to the imaging report. The distance of the appendix from anatomic landmarks was measured in a total of 114 pregnant women with an abdominal or pelvic MRI who were admitted between 2001 and 2011 at a Level I trauma center. Patients with a history of appendectomy were excluded. The distance from the base of the appendix to McBurney's point changed over the course of the gestation by only 1.2 cm and which did not amount to a clinically or statistically significant change in position. Our data provide evidence that there is minimal upward or lateral displacement of the appendix during pregnancy, and therefore its distance from the McBurney's point remains essentially unchanged. These findings justify the use of the McBurney's incision for appendectomy during pregnancy regardless of the trimester.

Appendectomy and pregnancy: gestational age does not affect the position of the incision

The position of the base of the appendix during advancing gestational age is based on inadequate data. Therefore, the proper location for an appendectomy incision during pregnancy is highly unclear. This study investigated the location of the appendix during pregnancy to determine the optimal location for an incision in pregnant patients with appendicitis relative to McBurney's point. Magnetic resonance images (MRIs) were reviewed independently by two fellowship-trained abdominal MRI radiologists blinded to the imaging report. The distance of the appendix from anatomic landmarks was measured in a total of 114 pregnant women with an abdominal or pelvic MRI who were admitted between 2001 and 2011 at a Level I trauma center. Patients with a history of appendectomy were excluded. The distance from the base of the appendix to McBurney's point changed over the course of the gestation by only 1.2 cm and which did not amount to a clinically or statistically significant change in position. Our data provide evidence that there is minimal upward or lateral displacement of the appendix during pregnancy, and therefore its distance from the McBurney's point remains essentially unchanged. These findings justify the use of the McBurney's incision for appendectomy during pregnancy regardless of the trimester.

Patterns of injury, outcomes, and predictors of in-hospital and 1-year mortality in nonagenarian and centenarian trauma patients

IMPORTANCE

With the dramatic growth in the very old population and their concomitant heightened exposure to traumatic injury, the trauma burden among this patient population is estimated to be exponentially increasing.

OBJECTIVE

To determine the clinical outcomes and predictors of in-hospital and 1-year mortality in nonagenarian and centenarian trauma patients (NCTPs).

DESIGN, SETTING, AND PARTICIPANTS

All patients 90 years or older admitted to a level 1 academic trauma center between January 1, 2006, and December 31, 2010, with a primary diagnosis of trauma were included. Standard trauma registry data variables were supplemented by systematic medical record review. Cumulative mortality rates at 1, 3, 6, and 12 months after discharge were investigated using the Social Security Death Index. Univariate and multivariable analyses were performed to identify the predictors of in-hospital and 1-year postdischarge cumulative mortalities.

MAIN OUTCOMES AND MEASURES

Length of hospital stay, in-hospital mortality, and cumulative mortalities at 1, 3, 6, and 12 months after discharge.

RESULTS

Four hundred seventy-four NCTPs were included; 71.7% were female, and a fall was the predominant mechanism of injury (96.4%). The mean patient age was 93 years, the mean Injury Severity Score was 12, and the mean number of comorbidities per patient was 4.4. The in-hospital mortality was 9.5% but cumulatively escalated at 1, 3, 6, and 12 months after discharge to 18.5%, 26.4%, 31.3%, and 40.5%, respectively. Independent predictors of in-hospital mortality were the Injury Severity Score (odds ratio [OR], 1.09; 95% CI, 1.02-1.16; P = .01), mechanical ventilation (OR, 6.23; 95% CI, 1.42-27.27; P = .02), and cervical spine injury (OR, 4.37; 95% CI, 1.41-13.50; P = .01). Independent predictors of cumulative 1-year mortality were head injury (OR, 2.65; 95% CI, 1.24-5.67; P = .03) and length of hospital stay (OR, 1.06; 95% CI, 1.02-1.11; P = .005). Cumulative 1-year mortality in NCTPs with a head injury was 51.1% and increased to 73.2% if the Injury Severity Score was 25 or higher and to 78.7% if mechanical ventilation was required. Most NCTPs required rehabilitation; only 8.9% were discharged to home.

CONCLUSIONS AND RELEVANCE

Despite low in-hospital mortality, the cumulative mortality rate among NCTPs at 1 year after discharge is significant, particularly in the presence of head injury, spine injury, mechanical ventilation, high injury severity, or prolonged length of hospital stay. These considerations can help guide clinical decisions and family discussions.

Trauma Whipple: do or don’t after severe pancreaticoduodenal injuries? An analysis of the National Trauma Data Bank (NTDB)

BACKGROUND

Pancreaticoduodenectomy for trauma (PDT) is a rare procedure, reserved for severe pancreaticoduodenal injuries. Using the National Trauma Data Bank (NTDB), our aim was to compare outcomes of PDT patients to similarly injured patients who did not undergo a PDT.

METHODS

Patients with pancreatic or duodenal injuries treated with PDT (ICD-9-CM 52.7) were identified in the NTDB 2008–2010 Research Data Sets. We excluded those who underwent delayed PDT (>4 days). The PDT group (n = 39) was compared to patients with severe combined pancreaticoduodenal injuries (grade 4 or 5) who did not undergo PDT (non-PDT group, n = 38). Patients who died in the emergency department or did not undergo a laparotomy were excluded. Our primary outcome was death. Secondary outcomes were intensive care unit length of stay (LOS), hospital LOS, and total ventilator days. A multivariate model was used to determine predictors of in-hospital mortality within each group and in the overall cohort.

RESULTS

The non-PDT group had a significantly lower systolic blood pressure and Glasgow Coma Scale values at baseline and more severe duodenal, pancreatic, and liver injuries. There were no significant differences in outcomes between the two groups. The Injury Severity Score was the only independent predictor of mortality among PDT patients [odds ratio (OR) 1.12, 95 % confidence interval (CI) 1.01–1.24] and in the entire cohort (OR 1.06, 95 % CI 1.01–1.12). The operative technique did not influence any of the outcomes.

CONCLUSIONS

Compared to non-PDT, PDT did not result in improved outcomes despite a lower physiologic burden among PDT patients. More conservative procedures for high-grade injuries of the pancreaticoduodenal complex may be appropriate.

The influence of anesthesia on heart rate complexity during elective and urgent surgery in 128 patients

BACKGROUND

As an emerging "new vital sign," heart rate complexity (by sample entropy [SampEn]) has been shown to be a useful trauma triage tool by predicting occult physiologic compromise and need for life-saving interventions. Sample entropy may be confounded by anesthesia possibly limiting its value intraoperatively. We investigated the effects of anesthesia on SampEn during elective and urgent surgical procedures. We hypothesized that SampEn is reduced by general anesthesia.

METHODS

With institutional review board-approved waiver of informed consent, 128 patients undergoing elective or urgent general surgery were prospectively enrolled. Real-time heart rate complexity was calculated using SampEn through electrocardiogram recordings of 200 consecutive beats in a continuous sliding-window fashion. We recorded SampEn starting 10 minutes before induction until 10 minutes after emergence from anesthesia. The time before induction of anesthesia was categorized as period 1, the time after induction and before emergence as period 2 (intraoperative), and the time after emergence as period 3. We analyzed SampEn changes as patients moved between the different periods and made 3 comparisons: from period 1 with period 2 (comparison A), from period 2 with period 3 (comparison B). We also compared period 1 with period 3 SampEn (comparison C).

RESULTS

The mean SampEn value for all patients before induction of anesthesia was 1.55 ± 0.58. In each 1 of the 3, comparisons there was a decline in SampEn. Comparison A had a mean decrease of 0.53 ± 0.55 (P < .0001), comparison B had a decrease of 0.13 ± 0.52 (P < .0051), and the mean SampEn difference for comparison C was 0.66 ± 0.53 (P < .0001). Certain pharmacologics had significant effect on SampEn as did need for urgent surgery and American Society of Anesthesiologists class.

CONCLUSION

Sample entropy decreases after induction of anesthesia and continues to decrease even immediately after emergence in patients without any immediately life-threatening conditions. This finding may complicate interpretation low complexity as a predictor of life-saving interventions in patients in the perioperative period.

Successful nonoperative management of the most severe blunt renal injuries: a multicenter study of the research consortium of New England Centers for Trauma

IMPORTANCE

Severe renal injuries after blunt trauma cause diagnostic and therapeutic challenges for the treating clinicians. The need for an operative vs a nonoperative approach is debated.

OBJECTIVE

To determine the rate, causes, predictors, and consequences of failure of nonoperative management (NOM) in grade IV and grade V blunt renal injuries (BRIs).

DESIGN

Retrospective case series.

SETTING

Twelve level I and II trauma centers in New England.

PARTICIPANTS

A total of 206 adult patients with a grade IV or V BRI who were admitted between January 1, 2000, and December 31, 2011.

MAIN OUTCOMES AND MEASURES

Failure of NOM, defined as the need for a delayed operation or death due to renal-related complications during NOM.

RESULTS

Of 206 patients, 52 (25.2%) were operated on immediately, and 154 (74.8%) were managed nonoperatively (with the assistance of angiographic embolization for 25 patients). Nonoperative management failed for 12 of the 154 patients (7.8%) and was related to kidney injury in 10 (6.5%). None of these 10 patients had complications because of the delay in BRI management. The mean (SD) time from admission to failure was 17.6 (27.4) hours (median time, 7.5 hours; range, 4.5-102 hours), and the cause was hemodynamic instability in 10 of the 12 patients (83.3%). Multivariate analysis identified 2 independent predictors of NOM failure: older than 55 years of age and a road traffic crash as the mechanism of injury. When both risk factors were present, NOM failure occurred for 27.3% of the patients; when both were absent, there were no NOM failures. Of the 142 patients successfully managed nonoperatively, 46 (32.4%) developed renal-related complications, including hematuria (24 patients), urinoma (15 patients), urinary tract infection (8 patients), renal failure (7 patients), and abscess (2 patients). These patients were managed successfully with no loss of renal units (ie, kidneys). The renal salvage rate was 76.2% for the entire population and 90.3% among patients selected for NOM.

CONCLUSIONS AND RELEVANCE

Hemodynamically stable patients with a grade IV or V BRI were safely managed nonoperatively. Nonoperative management failed for only 6.5% of patients owing to renal-related injuries, and three-fourths of the entire population retained their kidneys.

Development of a rugged handheld device for real-time analysis of heart rate: entropy in critically ill patients

INTRODUCTION

The usefulness of heart rate variability (HRV) and heart rate complexity (HRC) analysis as a potential triage tool has been limited by the inability to perform real-time analysis on a portable, handheld monitoring platform. Through a multidisciplinary effort of academia and industry, we report on the development of a rugged, handheld and noninvasive device that provides HRV and HRC analysis in real-time in critically ill patients.

METHODS

After extensive re-engineering, real-time HRV and HRC analyses were incorporated into an existing, rugged, handheld monitoring platform. Following IRB approval, the prototype device was used to monitor 20 critically ill patients and 20 healthy controls to demonstrate real-world discriminatory potential. Patients were compared to healthy controls using a Student?s t test as well as repeated measures analysis. Receiver operator characteristic (ROC) curves were generated for HRV and HRC.

RESULTS

Critically ill patients had a mean APACHE-2 score of 15, and over 50% were mechanically ventilated and requiring vasopressor support. HRV and HRC were both lower in the critically ill patients compared to healthy controls (p < 0.0001) and remained so after repeated measures analysis. The area under the ROC for HRV and HRC was 0.95 and 0.93, respectively.

CONCLUSIONS

This is the first demonstration of real-time, handheld HRV and HRC analysis. This prototype device successfully discriminates critically ill patients from healthy controls. This may open up possibilities for real-world use as a trauma triage tool, particularly on the battlefield.

Laparoscopic treatment of bowel obstruction due to a bezoar in a Meckel's diverticulum

BACKGROUND AND OBJECTIVES

Meckel's diverticulum is a common anomaly of the gastrointestinal tract that may result in gastrointestinal bleeding, diverticulitis, and small bowel obstruction. This report describes the use of laparoscopy to treat a rare complication of Meckel's diverticulum-small bowel obstruction due to phytobezoar impaction. More generally, it provides an example of the feasibility and utility of a laparoscopic approach to small bowel obstructions of unknown causes.

METHODS

A 34-year-old male presented to the emergency department complaining of episodic abdominal pain and vomiting. He had no history of abdominal surgery. His vital signs were stable, and his abdomen was distended, but only mildly tender. He had no abdominal wall hernias on examination. Imaging was consistent with small bowel obstruction. He was brought to the operating room where laparoscopy revealed a Meckel's diverticulum with an impacted phytobezoar as the source of obstruction. The diverticulum was resected and the phytobezoar removed laparoscopically.

RESULTS

The patient recovered well and was discharged home on the third postoperative day, tolerating a regular diet.

CONCLUSIONS

Phytobezoar impaction in a Meckel's diverticulum causing small bowel obstruction is a rare event. It can be effectively treated laparoscopically. This case provides an example of the potential utility of laparoscopy in treating small bowel obstructions of unclear etiology.

Intensive insulin therapy in brain injury: a meta-analysis

Many studies have addressed the question of whether intensive insulin therapy (IIT) provides better outcomes for brain-injured patients than does conventional insulin therapy (CIT), with conflicting results. We performed a systematic review and meta-analysis of the literature to estimate the effect of IIT on patients with brain injury. We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and citations of key articles and selected "all randomized controlled trials" (RCTs) comparing the effect of IIT to CIT among adult patients with acute brain injury (traumatic brain injury, stroke, subarachnoid hemorrhage, and encephalitis). Of the 2807 studies, we identified 9 RCTs with a total of 1160 patients for analysis. IIT did not appear to decrease the risk of in-hospital or late mortality (RR=1.04, 95% CI=0.75, 1.43 and RR=1.07, 95%CI=0.91, 1.27 respectively). No significant heterogeneity was found (I(2)=0.0%). IIT also did not have a protective effect on long-term neurological outcomes (LTNO) (RR=1.10, 95% CI=0.96, 1.27). IIT, however, did decrease the rate of infections (RR=0.76, 95% CI=0.58, 0.98). Heterogeneity was present (I(2)=64%), which was eliminated upon sensitivity analysis bringing the RR to 0.66 (95% CI=0.55, 0.80, I(2)=0%). IIT increased the rate of hypoglycemic episodes (RR=1.72, 95% CI=1.20, 2.46) however there was intractable heterogeneity present (I(2)=89%), which did not resolve upon sensitivity analysis. We found no evidence of publication bias by Egger's test (p=0.50). To conclude, IIT has no mortality or LTNO benefit to patients with brain injury, but is beneficial at decreasing infection rates.

Intraparenchymal vs extracranial ventricular drain intracranial pressure monitors in traumatic brain injury: less is more?

BACKGROUND

Management of severe traumatic brain injury has centered on continuous intracranial pressure (ICP) monitoring with intraparenchymal ICP monitors (IPM) or extracranial ventricular drains (EVD). Our hypothesis was that neurologic outcomes are unaffected by the type of ICP monitoring device.

STUDY DESIGN

We reviewed 377 adult patients with traumatic brain injury requiring ICP monitoring. Primary outcome was Glasgow Outcome Score (GOS) 1 month after injury. Secondary outcomes included mortality, monitoring-related complications, and length of ICU and hospital stay.

RESULTS

There were 253 patients managed with an IPM and 124 with an EVD. There was no difference in Glasgow Outcome Score (2.7 ± 1.3 vs 2.5 ± 1.3, p = 0.45), mortality (30.9% vs 32.2%, p = 0.82), and hospital length of stay (LOS) (15.6 ± 12.4 days vs 16.4 ± 10.7 days, p = 0.57). Device-related complications (11.9% vs 31.1%, p < 0.001), duration of ICP monitoring (3.8 ± 2.6 days vs 7.3 ± 5.6 days, p < 0.001), and ICU LOS (7.6 ± 5.6 days vs 9.5 ± 6.2 days, p = 0.004) were longer in the EVD group. Age, opening ICP, and size of midline shift were independent predictors for neurologic outcomes and mortality, when type and severity of brain injury, as well as overall injury severity were controlled for. Duration of ICP monitoring and opening ICP were independent predictors for hospital LOS and the former predicted prolonged ICU stay. Device-related complications were affected by type of device.

CONCLUSIONS

Use of EVDs in adult traumatic brain injury patients is associated with prolonged ICP monitoring, ICU LOS, and more frequent device-related complications.

Dynamic mechanical response of brain tissue in indentation in vivo, in situ and in vitro

Characterizing the dynamic mechanical properties of brain tissue is deemed important for developing a comprehensive knowledge of the mechanisms underlying brain injury. The results gathered to date on the tissue properties have been mostly obtained in vitro. Learning how these results might differ quantitatively from those encountered in vivo is a critical step towards the development of biofidelic brain models. The present study provides novel and unique experimental results on, and insights into, brain biorheology in vivo, in situ and in vitro, at large deformations, in the quasi-static and dynamic regimes. The nonlinear dynamic response of the cerebral cortex was measured in indentation on the exposed frontal and parietal lobes of anesthetized porcine subjects. Load-unload cycles were applied to the tissue surface at sinusoidal frequencies of 10, 1, 0.1 and 0.01 Hz. Ramp-relaxation tests were also conducted to assess the tissue viscoelastic behavior at longer times. After euthanasia, the indentation test sequences were repeated in situ on the exposed cortex maintained in its native configuration within the cranium. Mixed gray and white matter samples were subsequently excised from the superior cortex to be subjected to identical indentation test segments in vitro within 6-7 h post mortem. The main response features (e.g. nonlinearities, rate dependencies, hysteresis and conditioning) were measured and contrasted in vivo, in situ and in vitro. The indentation response was found to be significantly stiffer in situ than in vivo. The consistent, quantitative set of mechanical measurements thereby collected provides a preliminary experimental database, which may be used to support the development of constitutive models for the study of mechanically mediated pathways leading to traumatic brain injury.

Occult Pneumothorax in Trauma Patients: Development of an Objective Scoring System

BACKGROUND

The incidence of occult pneumothorax (OPTX) has dramatically increased since the widespread use of computed tomography (CT) scanning. The OPTX is defined as a pneumothorax not identified on plain chest X-ray but detected by CT scan. The overall reported incidence is about 5% to 8% of all trauma patients. We conducted a 5-year review of our OPTX incidence and asked if an objective score could be developed to better quantify the OPTX. This in turn may guide the practitioner with the decision to observe these patients.

METHODS

This is a retrospective review of all trauma patients in a Level I university trauma center during a 5-year period. The patients were identified by a query of all pneumothoraces in our trauma registry. Those X-ray results were then reviewed to identify those who had OPTX. After developing an OPTX score on a small number, we retrospectively scored 50 of the OPTXs by taking the largest perpendicular distance in millimeters from the chest wall of the largest air pocket. We then added 10 or 20 to this if the OPTX was either anterior/posterior or lateral, respectively.

RESULTS

A total of 21,193 trauma patients were evaluated and 1,295 patients with pneumothoraces (6.1%) were identified. Of the 1,295 patients with pneumothoraces, 379 (29.5%) OPTXs were identified. The overall incidence of OPTX was 1.8%: 95.7% occurred after blunt trauma, 222 (59%) of the OPTX patients had chest tubes and of the remaining 157 without chest tubes, 27 (17%) were on positive pressure ventilation. Of the 50 studies selected for scoring, the average score was 28.5. The average score for those with chest tubes was 34. The average score for those without chest tubes was 21. The positive predictive value for need of chest tube if the score was >30 was 78% and the negative predictive value if the score was <20 was 70%. Area under the receiver operator characteristic curve was 0.72, which was significant with p < 0.007.

CONCLUSIONS

The OPTX score could quantify the size of the OPTX allowing the practitioner to better define a "small" pneumothorax. The management of OPTX is not standardized and further study using a more objective classification may assist the surgeon's decision-making. The application of a scoring system may also decrease unnecessary insertion of chest tubes for small OPTXs and is currently being prospectively validated.

Cerebrovascular resuscitation after polytrauma and fluid restriction

BACKGROUND

There are few reproducible models of blast injury, so it is difficult to evaluate new or existing therapies. We developed a clinically relevant polytrauma model to test the hypothesis that cerebrovascular resuscitation is optimized when intravenous fluid is restricted.

STUDY DESIGN

Anesthetized swine (42+/-5 kg, n=35) received blasts to the head and bilateral chests with captive bolt guns, followed by hypoventilation (4 breaths/min; FiO(2)=0.21). After 30 minutes, resuscitation was divided into phases to simulate typical prehospital, emergency room, and ICU care. For 30 to 45 minutes, group 1, the control group (n=5), received 1L of normal saline (NS). For 45 to 120 minutes, additional NS was titrated to mean arterial pressure (MAP) > 60 mmHg. After 120 minutes, mannitol (1g/kg) and phenylephrine were administered to manage cerebral perfusion pressure (CPP) > 70 mmHg, plus additional NS was given to maintain central venous pressure (CVP) > 12 mmHg. In group 2 (n=5), MAP and CPP targets were the same, but the CVP target was>8 mmHg. Group 3 (n=5) received 1 L of NS followed only by CPP management. Group 4 (n=5) received Hextend (Abbott Laboratories), instead of NS, to the same MAP and CPP targets as group 2.

RESULTS

Polytrauma caused 13 deaths in the 35 animals. In survivors, at 30 minutes, MAP was 60 to 65 mmHg, heart rate was >100 beats/min, PaO(2) was < 50 mmHg, and lactate was>5 mmol/L. In two experiments, no fluid or pressor was administered; the tachycardia and hypotension persisted. The first liter of intravenous fluid partially corrected these variables, and also partially corrected mixed venous O(2), gastric and portal venous O(2), cardiac output, renal blood flow, and urine output. Additional NS (total of 36+/-1 mL/kg/h and 17+/-6 mL/kg/h, in groups 1 and 2, respectively) correlated with increased intracranial pressure to 38+/-4 mmHg (group 1) and 26+/-4 mmHg (group 2) versus 22+/-4 mmHg in group 3 (who received 5+/-1 mL/kg/h). CPP was maintained only after mannitol and phenylephrine. By 5 hours, brain tissue PO(2) was>20 mmHg in groups 1 and 2, but only 6+/-1 mmHg in group 3. In contrast, minimal Hextend (6+/-3 mL/kg/h) was needed; the corrections in MAP and CPP were immediate and sustained, intracranial pressure was lower (14+/-2 mmHg), and brain tissue PO(2) was> 20 mmHg. Neuropathologic changes were consistent with traumatic brain injury, but there were no statistically significant differences between groups.

CONCLUSIONS

After polytrauma and resuscitation to standard MAP and CPP targets with mannitol and pressor therapy, we concluded that intracranial hypertension was attenuated and brain oxygenation was maintained with intravenous fluid restriction; cerebrovascular resuscitation was optimized with Hextend versus NS; and longer term studies are needed to determine neuropathologic consequences.