Factors Associated With Pelvic Infection After Pre-Peritoneal Pelvic Packing for Hemodynamically Unstable Pelvic Fractures.

Background: Preperitoneal pelvic packing (PPP) and external fixation has led to improved mortality after devastating pelvic trauma. However, there is limited literature on infection after this intervention. We aim to study the risk factors associated with pelvic infection after PPP. Patients and Methods: A retrospective review of patients who underwent PPP at a single level 1 trauma center was performed. Results: Over the 18-year study period, 222 patients were identified. Twenty-three percent of patients had an open fracture. Pelvic angiography was performed in 24% of patients with 16% requiring angioembolization (AE). The average time to packing removal was two (one to two days) days, although 10% of patients had their pelvis re-packed. Overall infection rate was 14% (n = 31); if pelvic re-packing was performed, the infection rate increased to 45%. Twenty-two of the patients with an infection required additional procedures for their infection, and ultimately hardware removal occurred in eight patients. On univariable analysis, patients with pelvic infections had more open fractures (55% vs. 17%; p < 0.01), underwent AE more frequently (29% vs. 14%; p = 0.04), were more likely to undergo repacking (32% vs. 6%; p < 0.01), and had packing in place for longer (2 [1,2] vs. 2 [2,3]; p = 0.01). On logistic multivariable regression analysis, open fracture (odds ratio [OR], 5.8; 95% confidence interval [CI], 2.4-14.1) and pelvic re-packing (OR, 4.7; 95% CI, 1.2-18.5) were independent risk factors for pelvic infection. Conclusions: Pelvic infection after PPP is a serious complication independently associated with open fracture and re-packing of the pelvis. Re-intervention was required in most patients with infection.

Management of Pelvic Trauma.

Pelvic fractures are common after blunt trauma with patients' presentation ranging from stable with insignificant fractures to life-threatening exsanguination from unstable fractures. Often, hemorrhagic shock from a pelvic fracture may go unrecognized and high clinical suspicion for a pelvic source lies with the clinician. A multidisciplinary coordinated effort is required for management of these complex patients. In the exsanguinating patient, hemorrhage control remains the top priority and may be achieved with external stabilization, resuscitative endovascular balloon occlusion of the aorta, preperitoneal pelvic packing, angiographic intervention, or a combination of therapies. These modalities have been shown to reduce mortality in this challenging population.

High-grade liver injuries with contrast extravasation managed initially with interventional radiology versus observation: A secondary analysis of a WTA multicenter study.

BACKGROUND: High-grade liver injuries with extravasation (HGLI â€‹+ â€‹Extrav) are associated with morbidity/mortality. For low-grade injuries, an observation (OBS) first-strategy is beneficial over initial angiography (IR), however, it is unclear if OBS is safe for HGLI â€‹+ â€‹Extrav. Therefore, we evaluated the management of HGLI â€‹+ â€‹Extrav patients, hypothesizing IR patients will have decreased rates of operation and mortality. METHODS: HGLI â€‹+ â€‹Extrav patients managed with initial OBS or IR were included. The primary outcome was need for operation. Secondary outcomes included liver-related complications (LRCs) and mortality. RESULTS: From 59 patients, 23 (39.0%) were managed with OBS and 36 (61.0%) with IR. 75% of IR patients underwent angioembolization, whereas 13% of OBS patients underwent any IR, all undergoing angioembolization. IR patients had an increased rate of operation (13.9% vs. 0%, p â€‹= â€‹0.049), but no difference in LRCs (44.4% vs. 43.5%) or mortality (5.6% vs. 8.7%) versus OBS patients (both p â€‹> â€‹0.05). CONCLUSION: Over 60% of patients were managed with IR initially. IR patients had an increased rate of operation yet similar rates of LRCs and mortality, suggesting initial OBS reasonable in appropriately selected HGLI â€‹+ â€‹Extrav patients.

Evolution of Pulmonary Contusions in Patients With Severe Rib Fractures: Cause for Concern?

INTRODUCTION: The progression of pulmonary contusions remains poorly understood. This study aimed to measure the radiographic change in pulmonary contusions over time and evaluate the association of the radiographic change with clinical outcomes and surgical stabilization of rib fractures (SSRF). METHODS: This retrospective cohort study included adults admitted with three or more displaced rib fractures or flail segment on trauma CT and when a chest CT was repeated within one week after trauma. Radiographic severity of pulmonary contusions was assessed using the Blunt Pulmonary Contusion Score (BPC18). Logistic regression was performed to evaluate the relation between SSRF and worsening contusions on repeat CT, adjusted for potential confounders. RESULTS: Of 231 patients, 56 (24%) had a repeat CT scan. Of these, 55 (98%) had pulmonary contusion on the first CT scan with a median BPC18 score of 5 (P25-P75 3-7). Repeat CTs showed an overall decrease of the median BPC18 score to 4 (P25-P75 2-6, P = .02), but demonstrated a worsening of the pulmonary contusion in 16 patients (29%). All repeat CTs conducted within 12 hours post-injury demonstrated increasing BPC18. Radiographic worsening of pulmonary contusions was not associated with SSRF, nor with worse respiratory outcomes or intensive care length of stay, compared to patients with radiographically stable or improving contusions. DISCUSSION: In patients with severe rib fracture patterns who undergo repeat imaging, pulmonary contusions are prevalent and become radiographically worse within at least the first 12 hours after injury. No association between radiographic worsening and clinical outcomes was found.

American Association for the Surgery of Trauma/American College of Surgeons Committee on Trauma clinical protocol for management of acute respiratory distress syndrome and severe hypoxemia.

LEVEL OF EVIDENCE: Therapeutic/Care Management: Level V.

Early Surgical Stabilization of Rib Fractures is Feasible in Patients With Non-Urgent Operative Pelvic Injuries.

INTRODUCTION: The feasibility of prioritizing surgical stabilization of rib fractures (SSRF) in patients with other injuries is unknown. The purpose of this study was to evaluate the timing and outcomes of SSRF between patients with and without non-urgent operative pelvic injuries. PATIENTS AND METHODS: In this retrospective observational study, all patients between 2010 and 2020 who underwent SSRF (SSRF group) and those who underwent SSRF and non-urgent operative management of pelvic fractures (SSRF + P group) were included. Demographics, injury characteristics, operative details, and outcomes were compared between the 2 groups. RESULTS: Over 11 years, 154 SSRF patients were identified, with 143 patients in the SSRF group (93%) and 11 patients in the SSRF + P group (7%). Median number of rib fractures (7 vs 9, P = .04), total number of fractures (11 vs 15, P < .01), and flail segment (54% vs 91%, P = .02) were higher in SSRF + P group. Median time to SSRF was similar (0 vs 1 day, P = .20) between the 2 groups. Median time to pelvic fixation was 3 days in SSRF + P group and 8 out of 11 patients (73%) underwent SSRF prior to pelvic fixation. Median operative time (137 vs 178 mins, P = .14) and median number of ribs plated (4 vs 5, P = .05) were higher in SSRF + P group. There was no difference in SSRF-related complications, pelvic fracture-related complications from operative positioning, rates of pneumonia, or mortality between the 2 groups. CONCLUSIONS: SSRF can be performed early in patients with non-urgent operative pelvic injuries without a difference in pelvic fracture-related complications, SSRF-related complications, pneumonia, or mortality.

Contemporary management and outcomes of penetrating colon injuries: Validation of the 2020 AAST Colon Organ Injury Scale.

INTRODUCTION: The American Association for the Surgery of Trauma Colon Organ Injury Scale (OIS) was updated in 2020 to include a separate OIS for penetrating colon injuries and included imaging criteria. In this multicenter study, we describe the contemporary management and outcomes of penetrating colon injuries and hypothesize that the 2020 OIS system correlates with operative management, complications, and outcomes. METHODS: This was a retrospective study of patients presenting to 12 Level 1 trauma centers between 2016 and 2020 with penetrating colon injuries and Abbreviated Injury Scale score of <3 in other body regions. We assessed the association of the new OIS with surgical management and clinical outcomes and the association of OIS imaging criteria with operative criteria. Bivariate analysis was done with χ 2 , analysis of variance, and Kruskal-Wallis, where appropriate. Multivariable models were constructed in a stepwise selection fashion. RESULTS: We identified 573 patients with penetrating colon injuries. Patients were young and predominantly male; 79% suffered a gunshot injury, 11% had a grade V destructive injury, 19% required ≥6 U of transfusion, 24% had an Injury Severity Score of >15, and 42% had moderate-to-large contamination. Higher OIS was independently associated with a lower likelihood of primary repair, higher likelihood of resection with anastomosis and/or diversion, need for damage-control laparotomy, and higher incidence of abscess, wound infection, extra-abdominal infections, acute kidney injury, and lung injury. Damage control was independently associated with diversion and intra-abdominal and extra-abdominal infections. Preoperative imaging in 152 (27%) cases had a low correlation with operative findings ( κ coefficient, 0.13). CONCLUSION: This is the largest study to date of penetrating colon injuries and the first multicenter validation of the new OIS specific to these injuries. While imaging criteria alone lacked strong predictive value, operative American Association for the Surgery of Trauma OIS colon grade strongly predicted type of interventions and outcomes, supporting use of this grading scale for research and clinical practice. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level III.

An observation-first strategy for liver injuries with "blush" on computed tomography is safe and effective.

INTRODUCTION: The management of liver injuries in hemodynamically stable patients is variable and includes primary treatment strategies of observation (OBS), angiography (interventional radiology [IR]) with angioembolization (AE), or operative intervention (OR). We aimed to evaluate the management of patients with liver injuries with active extravasation on computed tomography (CT) imaging, hypothesizing that AE will have more complications without improving outcomes compared with OBS. METHODS: This is a prospective, multicenter, observational study. Patients who underwent CT within 2 hours after arrival with extravasation (e.g., blush) on imaging were included. Exclusion criteria included cirrhosis, nontraumatic hemorrhage, transfers from outside facilities, and pregnancy. No hemodynamic exclusion criteria were used. The primary outcome was liver-specific complications. Secondary outcomes include length of stay and mortality. Angioembolization patients were compared with patients treated without AE. Propensity score matching was used to match based on penetrating mechanism, liver injury severity, arrival vital signs, and early transfusion. RESULTS: Twenty-three centers enrolled 192 patients. Forty percent of patients (n = 77) were initially OBS. Eleven OBS patients (14%) failed nonoperative management and went to IR or OR. Sixty-one patients (32%) were managed with IR, and 42 (69%) of these had AE as an initial intervention. Fifty-four patients (28%) went to OR+/- IR. After propensity score matching (n = 34 per group), there was no difference in baseline characteristics between AE and OBS. The AE group experienced more complications with a higher rate of IR-placed drains for abscess or biloma (22% vs. 0%, p = 0.01) and an increased overall length of stay ( p = 0.01). No difference was noted in transfusions or mortality. CONCLUSION: Observation is highly effective with few requiring additional interventions. Angioembolization was associated with higher rate of secondary drain placement for abscesses or biloma. Given this, a trial of OBS and avoidance of empiric AE may be warranted in hemodynamically stable, liver-injured patient with extravasation on CT. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level II.

Rib fixation in patients with severe rib fractures and pulmonary contusions: Is it safe?

BACKGROUND: Pulmonary contusion has been considered a contraindication to surgical stabilization of rib fractures (SSRFs). This study aimed to evaluate the association between pulmonary contusion severity and outcomes after SSRF. We hypothesized that outcomes would be worse in patients who undergo SSRF compared with nonoperative management, in presence of varying severity of pulmonary contusions. METHODS: This retrospective cohort study included adults with three or more displaced rib fractures or flail segment. Patients were divided into those who underwent SSRF versus those managed nonoperatively. Severity of pulmonary contusions was assessed using the Blunt Pulmonary Contusion 18 (BPC18) score. Outcomes (pneumonia, tracheostomy, mechanical ventilation days, intensive care unit (ICU) length of stay, hospital length of stay, mortality) were retrieved from patients' medical records. Comparisons were made using Fisher's exact and Kruskal-Wallis tests, and correction for potential confounding was done with regression analyses. RESULTS: A total of 221 patients were included; SSRF was performed in 148 (67%). Demographics and chest injury patterns were similar in SSRF and nonoperatively managed patients. Surgical stabilization of rib fracture patients had less frequent head and abdominal/pelvic injuries ( p = 0.017 and p = 0.003). Higher BPC18 score was associated with worse outcomes in both groups. When adjusted for ISS, the ICU stay was shorter (adjusted ß , -2.511 [95% confidence interval, -4.87 to -0.16]) in patients with mild contusions who underwent SSRF versus nonoperative patients. In patients with moderate contusions, those who underwent SSRF had fewer ventilator days (adjusted ß , -5.19 [95% confidence interval, -10.2 to -0.17]). For severe pulmonary contusions, outcomes did not differ between SSRF and nonoperative management. CONCLUSION: In patients with severe rib fracture patterns, higher BPC18 score is associated with worse respiratory outcomes and longer ICU and hospital admission duration. The presence of pulmonary contusions is not associated with worse SSRF outcomes, and SSRF is associated with better outcomes for patients with mild to moderate pulmonary contusions. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

Inflate and pack! Pelvic packing combined with REBOA deployment prevents hemorrhage related deaths in unstable pelvic fractures.

INTRODUCTION: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is advocated for hemorrhage control in pelvic fracture patients in shock. We evaluated REBOA in patients undergoing preperitoneal pelvic packing (PPP) for pelvic fracture-related hemorrhage. METHODS: Retrospective, single-institution study of unstable pelvic fractures (hemodynamic instability despite 2 units of red blood cells (RBCs) and fracture identified on x-ray). Management included the placement of a Zone III REBOA in the emergency department (ED) for systolic blood pressure <80 mmHg. All PPP patients were included and analyzed for injury characteristics, transfusion requirements, outcomes and complications. Additionally, patients who received REBOA (REBOA+) were compared to those that did not (REBOA-). RESULTS: During the study period (January 2015 - January 2019), 652 pelvic fracture patients were admitted; 78 consecutive patients underwent PPP. Median RBCs at PPP completion compared to 24 h post-packing were 11 versus 3 units (p<0.05). Median time to operation was 45 min. After PPP, 7 (9%) patients underwent angioembolization. Mortality was 14%. No mortalities were due to ongoing pelvic fracture hemorrhage or physiologic exhaustion; all were a withdrawal of life sustaining support, most commonly due to neurologic insults (TBI/fat emboli = 6, stroke/spinal cord injury = 3). REBOA+ patients (n = 31) had a significantly higher injury severity score (45 vs 38, p<0.01) and higher heart rate (130 vs 118 beats per minute, p = 0.04) than REBOA-. The systolic blood pressure, base deficit, and number of RBCs transfused in the ED, and time spent in the ED were similar between groups. REBOA+ had a higher median transfusion of RBCs at PPP completion (11 units vs 5 units, p<0.01) but similar RBC transfusion in the 24 h after PPP (2 vs 1 units, p = 0.27). Mortality, pelvic infection, and ICU length of stay was not different between these cohorts. CONCLUSION: PPP with REBOA was utilized in more severely injured patients with greater physiologic derangements. Although REBOA patients required greater transfusion requirements, there were no deaths due to acute pelvic hemorrhage. This suggests the combination of REBOA with PPP provides life-saving hemorrhage control in otherwise devastating injuries.

Time to Look for Another Infectious Source? White Blood Cell Trends during Ventilator-Associated Pneumonia.

Background: Ventilator-associated pneumonia (VAP) continues to plague patients in intensive care units (ICUs) throughout the world. Persistent leukocytosis despite antibiotic treatment for VAP can have many etiologies including normal inflammatory response, inadequate VAP antimicrobial therapy, and the presence of additional infectious diagnoses. Hypothesis: Surgical patients with VAP and a second infectious source have a different white blood cell count (WBC) trend than patients with VAP alone. Patients and Methods: Retrospective, single-center study of surgical ICU patients diagnosed with VAP (>104 CFU/mL on semi-quantitative culture) between January 2019 and June 2020. Chart review identified additional infections diagnosed during VAP treatment. White blood cell count values were compared between patients treated for VAP alone (VAP-alone) and those with additional infections (VAP-plus) using a Wilcoxon test. Univariable analysis compared admission type, surgeries, and steroid use between cohorts. Results: Eighty-eight VAPs were included for analysis; 61 (69%) were VAP-alone and 27 (31%) VAP-plus. Average age was 47.1 ± 16.7 years, 78% were male, and 93% were trauma admissions. Median hospital day of VAP diagnosis was six (interquartile range [IQR], 4-10). Nearly all patients (99%) were started on initial antibiotic agents to which the VAP organism was sensitive. Daily WBC was higher for VAP-plus compared with VAP-alone on days five, six, and seven of treatment. The maximum WBC was higher for VAP-plus (21.6 k/mcL vs. 16.1 k/mcL; p = 0.02). There were no differences in admission types, number of surgeries, or steroid use between groups. Conclusions: Providers should have increased suspicion for additional sources of infection when ICU patients with a VAP continue to have elevated WBC despite appropriate antibiotic therapy.

Assessment of Discharge Analgesic Prescription Patterns for Hospitalized Patients With Rib Fractures.

INTRODUCTION: There is a paucity of data describing opioid prescribing patterns for trauma patients. We investigated pain medication regimens prescribed at discharge for patients with traumatic rib fractures, as well as potential variables predictive of opioid prescribing. METHODS: A single-center, retrospective analysis was performed of 337 adult patients presenting with ≥1 traumatic rib fractures between January and December 2019. The primary outcome was oral morphine milligram equivalents (MME) prescribed on discharge. A multivariable logistic regression analysis was performed to determine factors independently associated with above median (150) MME prescription at discharge. RESULTS: The majority of patients were male (68.8%) with a median age of 53 y. Blunt trauma accounted for 97.3% of cases with a median Injury Severity Score(ISS) of 10. Locoregional pain procedures were utilized in 16.9% of patients. Opioids were the most common analgesic prescribed at discharge, and 74.1% of patients prescribed opioids on discharge were also prescribed a non-opioid adjunct. On multivariable analysis, daily MME prescribed during hospitalization (OR 1.01, 95% CI 1.01-1.02, P < 0.01) and number of rib fractures (OR 2.26, 95% CI 1.36-3.74, P < 0.01) were predictive of high MME prescribed on discharge. CONCLUSIONS: For patients with traumatic rib fractures, daily MME during hospitalization and number of rib fractures were predictive of high MME prescribing on discharge. Further prospective studies evaluating strategies for pain management and protocolized approaches to opioid prescribing are needed to reduce unnecessary and inappropriate opioid use in this patient population.

Surgical Site Infection after Surgical Stabilization of Rib Fractures: Rare but Morbid.

Background: Although surgical stabilization for rib fractures (SSRF) has been adopted widely over the past decade, little information is available regarding the prevalence and outcomes of post-operative surgical site infection (SSI). We hypothesized that SSI after SSRF is uncommon but morbid. Patients and Methods: Patients undergoing SSRF at a level 1 trauma center from 2010-2020 were reviewed. The primary outcome was the prevalence of SSI, documented by clinical examination, radiography, systemic markers of infection, and microbiology. Results: Of 228 patients undergoing SSRF, 167 (73.2%) were male, the median age was 53 years (P25-P75; 41-63 years), injury severity score (ISS) was 19 (P25-P75, 13-26), with a median of eight fractured ribs (P25-P75, 6-11). All stabilization plates were titanium. SSRF was typically performed on post-injury day one (P25-P75, 0-2 days) after trauma. All patients received antibiotic agents within 30 minutes of incision, and a median of four ribs (P25-P75, 3-6) were repaired. Four (1.8%) patients developed an SSI and all underwent implant removal. Two patients required implant removal within 30 days (on post-operative day seven and 17) and two for chronic infection at seven and 17 months after SSRF. The causative organism was methicillin-sensitive Staphylococcus aureus (MSSA) bacteria in all patients. After implant removal, three patients received intravenous and oral antibiotic agents, ranging from two to six weeks, without recurrent infection. No patient required additional SSRF. Conclusions: Surgical site infection after SSRF is rare but morbid and can become symptomatic within one week to 17 months. Implant removal results in complete recovery.

A decade of surgical stabilization of rib fractures: the effect of study year on patient selection, operative characteristics, and in-hospital outcome.

BACKGROUND: Many centers now perform surgical stabilization of rib fractures (SSRF). This single center study aimed to investigate temporal trends by year in patient selection, operative characteristics, and in-hospital outcomes We hypothesized that, over time, patient selection, time to SSRF, operative time, and in-hospital outcomes varied significantly. METHODS: A retrospective review of a prospectively maintained SSRF database (2010 to 2020) was performed. Patients were stratified by year in which they underwent SSRF. The primary outcome was operative time, defined in minutes from incision to closure. Secondary outcomes were patient and operative characteristics, and in-hospital outcomes. Multivariable regression analyses were performed to assess for temporal trends, corrected for confounders. The outcomes ventilator-, Intensive Care Unit-, and hospital-free days (VFD, IFD, and HFD, respectively) were categorized based on the group's medians, and complications were combined into a composite outcome. RESULTS: In total, 222 patients underwent SSRF on a median of one day after admission (P25-P75, 0-2). Patients had a median age of 54 years (P25-P75, 42-63), ISS of 19 (P25-P75, 13-26), RibScore of 3 (P25-P75, 2-5), and sustained a median of 8 fractured ribs (P25-P75, 6-11). In multivariable analysis, increasing study year was associated with an increase in operative time (p<0.0001). In addition, study year was associated with a significantly reduced odds of complications (Odds ratio [OR], 0.76; 95% Confidence Interval [95% CI], 0.63-0.92; p=0.005), VFD < 28 days (OR, 0.77; 95% CI, 0.65-0.92; p=0.003), IFD < 24 days (OR, 0.77; 95% CI, 0.66-0.91; p=0.002), and HFD < 18 days (OR, 0.64; 95% CI, 0.53-0.76; p<0.0001). CONCLUSION: In-hospital outcomes after SSRF improved over time. Unexpectedly, operative time increased. The reason for this finding is likely multifactorial and may be related to patient selection, onboarding of new surgeons, fracture characteristics, and minimally invasive exposures. Due to potential for confounding, study year should be accounted for when evaluating outcomes of SSRF.

Pelvic fracture-related hypotension: A review of contemporary adjuncts for hemorrhage control.

ABSTRACT: Major pelvic hemorrhage remains a considerable challenge of modern trauma care associated with mortality in over a third of patients. Efforts to improve outcomes demand continued research into the optimal employment of both traditional and newer hemostatic adjuncts across the full spectrum of emergent care environments. The purpose of this review is to provide a concise description of the rationale for and effective use of currently available adjuncts for the control of pelvic hemorrhage. In addition, the challenges of defining the optimal order and algorithm for employment of these adjuncts will be outlined. LEVEL OF EVIDENCE: Review, level IV.

An Artificial Placenta Protects Against Lung Injury and Promotes Continued Lung Development in Extremely Premature Lambs.

An artificial placenta (AP) utilizing extracorporeal life support (ECLS) could protect premature lungs from injury and promote continued development. Preterm lambs at estimated gestational age (EGA) 114-128 days (term = 145) were delivered by Caesarian section and managed in one of three groups: AP, mechanical ventilation (MV), or tissue control (TC). Artificial placenta lambs (114 days EGA, n = 3; 121 days, n = 5) underwent venovenous (VV)-ECLS with jugular drainage and umbilical vein reinfusion for 7 days, with a fluid-filled, occluded airway. Mechanical ventilation lambs (121 days, n = 5; 128 days, n = 5) underwent conventional MV until failure or maximum 48 hours. Tissue control lambs (114 days, n = 3; 121 days, n = 5; 128 days, n = 5) were sacrificed at delivery. At the conclusion of each experiment, lungs were procured and sectioned. Hematoxylin and eosin (H&E) slides were scored 0-4 in seven injury categories, which were summed for a total injury score. Slides were also immunostained for platelet-derived growth factor receptor (PDGFR)-α and α-actin; lung development was quantified by the area fraction of double-positive tips of secondary alveolar septa. Support duration of AP lambs was 163 ± 9 (mean ± SD) hours, 4 ± 3 for early MV lambs, and 40 ± 6 for late MV lambs. Total injury scores at 121 days were 1.7 ± 2.1 for AP vs. 5.5 ± 1.6 for MV (p = 0.02). Using immunofluorescence, double-positive tip area fraction at 121 days was 0.017 ± 0.011 in AP lungs compared with 0.003 ± 0.003 in MV lungs (p < 0.001) and 0.009 ± 0.005 in TC lungs. At 128 days, double-positive tip area fraction was 0.012 ± 0.007 in AP lungs compared with 0.004 ± 0.004 in MV lungs (p < 0.001) and 0.016 ± 0.009 in TC lungs. The AP is protective against lung injury and promotes lung development compared with mechanical ventilation in premature lambs.

Effects of an artificial placenta on brain development and injury in premature lambs.

PURPOSE: We evaluated whether brain development continues and brain injury is prevented during Artificial Placenta (AP) support utilizing extracorporeal life support (ECLS). METHODS: Lambs at EGA 118days (term=145; n=4) were placed on AP support (venovenous ECLS with jugular drainage and umbilical vein reinfusion) for 7days and sacrificed. Early (EGA 118; n=4) and late (EGA 127; n=4) mechanical ventilation (MV) lambs underwent conventional MV for up to 48h and were sacrificed, and early (n=5) and late (n=5) tissue control (TC) lambs were sacrificed at delivery. Brains were harvested, formalin-fixed, rehydrated, and studied by magnetic resonance imaging (MRI). The gyrification index (GI), a measure of cerebral folding complexity, was calculated for each brain. Diffusion-weighted imaging was used to determine fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in multiple structures to assess white matter (WM) integrity. RESULTS: No intracranial hemorrhage was observed. GI was similar between AP and TC groups. ADC and FA did not differ between AP and late TC groups in any structure. Compared to late MV brains, AP brains demonstrated significantly higher ADC (0.45±0.08 vs. 0.27±0.11, p=0.02) and FA (0.61±0.04 vs. 0.44±0.05; p=0.006) in the cerebral peduncles. CONCLUSIONS: After 7days of AP support, WM integrity is preserved relative to mechanical ventilation. TYPE OF STUDY: Research study.

Ex Situ Perfusion of Human Limb Allografts for 24 Hours.

BACKGROUND: Vascularized composite allografts, particularly hand and forearm, have limited ischemic tolerance after procurement. In bilateral hand transplantations, this demands a 2 team approach and expedited transfer of the allograft, limiting the recovery to a small geographic area. Ex situ perfusion may be an alternative allograft preservation method to extend allograft survival time. This is a short report of 5 human limbs maintained for 24 hours with ex situ perfusion. METHODS: Upper limbs were procured from brain-dead organ donors. Following recovery, the brachial artery was cannulated and flushed with 10 000 U of heparin. The limb was then attached to a custom-made, near-normothermic (30-33°C) ex situ perfusion system composed of a pump, reservoir, and oxygenator. Perfusate was plasma-based with a hemoglobin concentration of 4 to 6 g/dL. RESULTS: Average warm ischemia time was 76 minutes. Perfusion was maintained at an average systolic pressure of 93 ± 2 mm Hg, flow 310 ± 20 mL/min, and vascular resistance 153 ± 16 mm Hg/L per minute. Average oxygen consumption was 1.1 ± 0.2 mL/kg per minute. Neuromuscular electrical stimulation continually displayed contraction until the end of perfusion, and histology showed no myocyte injury. CONCLUSIONS: Human limb allografts appeared viable after 24 hours of near-normothermic ex situ perfusion. Although these results are early and need validation with transplantation, this technology has promise for extending allograft storage times.

The University of Michigan Experience with Veno-Venoarterial Hybrid Mode of Extracorporeal Membrane Oxygenation.

The veno-venoarterial (VVA) mode of extracorporeal membrane oxygenation (ECMO) is defined by having both venous and arterial reinfusion cannulas. It is purposed to improve upper body oxygenation as the venous reinfusion cannula is typically placed in the upper body. We performed a single-center retrospective review to better characterize the patients placed on this mode. Adults (n = 23) were 40.4 ± 14.7 years old and were supported with ECMO for a median of 141 (97, 253) hours, with VVA support 110 (63, 179) hours. Ten (43%) were initially cannulated VVA; reasons for conversion included cardiac failure (46%), North-South syndrome (38%), and worsening hypoxia (15%). Survival was 39% and neurological complications 13%. Pediatrics (n = 8) were 13.0 ± 2.4 years old and were supported with ECMO for a median of 258 (168, 419) hours, with VVA support 131 (98, 161) hours. One (12.5%) was initially cannulated VVA; reasons for conversion were North-South syndrome (42%), cardiac failure (29%), and worsening hypoxia (29%). Survival was 71% and neurological complications 29%. We concluded that there was neither survival advantage nor complication reduction with the VVA mode in this cohort; however, VVA does have value for unique clinical situations when conventional ECMO modes do not meet support needs.