Low Anti-Factor Xa Level Predicts 90-Day Symptomatic Venous Thromboembolism in Surgical Patients Receiving Enoxaparin Prophylaxis: A Pooled Analysis of Eight Clinical Trials.

OBJECTIVE: To examine the relationship between enoxaparin dose adequacy, quantified with anti-Factor Xa (aFXa) levels, and 90-day symptomatic venous thromboembolism (VTE) and postoperative bleeding. SUMMARY BACKGROUND DATA: Surgical patients often develop "breakthrough" VTE events-those which occur despite receiving chemical anticoagulation. We hypothesize that surgical patients with low aFXa levels will be more likely to develop 90-day VTE, and those with high aFXa will be more likely to bleed. METHODS: Pooled analysis of eight clinical trials (N = 985) from a single institution over a 4 year period. Patients had peak steady state aFXa levels in response to a known initial enoxaparin dose, and were followed for 90 days. Survival analysis log-rank test examined associations between aFXa level category and 90-day symptomatic VTE and bleeding. RESULTS: Among 985 patients, 2.3% (n = 23) had symptomatic 90-day VTE, 4.2% (n = 41) had 90-day clinically relevant bleeding, and 2.1% (n = 21) had major bleeding. Patients with initial low aFXa were significantly more likely to have 90-day VTE than patients with adequate or high aFXa (4.2% vs 1.3%, P = 0.007). In a stratified analysis, this relationship was significant for patients who received twice daily (6.2% vs 1.5%, P = 0.003), but not once daily (3.0% vs 0.7%, P = 0.10) enoxaparin. No association was seen between high aFXa and 90-day clinically relevant bleeding (4.8% vs 2.9%, P = 0.34) or major bleeding (3.6% vs 1.6%, P = 0.18). CONCLUSIONS: This manuscript establishes inadequate enoxaparin dosing as a plausible mechanism for breakthrough VTE in surgical patients, and identifies anticoagulant dose adequacy as a novel target for process improvement measures.

Trauma and hemorrhagic shock activate molecular association of 5-lipoxygenase and 5-lipoxygenase-Activating protein in lung tissue.

BACKGROUND: Post-traumatic lung injury following trauma and hemorrhagic shock (T/HS) is associated with significant morbidity. Leukotriene-induced inflammation has been implicated in the development of post-traumatic lung injury through a mechanism that is only partially understood. Postshock mesenteric lymph returning to the systemic circulation is rich in arachidonic acid, the substrate of 5-lipoxygenase (ALOX5). ALOX5 is the rate-limiting enzyme in leukotriene synthesis and, following T/HS, contributes to the development of lung dysfunction. ALOX5 colocalizes with its cofactor, 5-lipoxygenase-activating protein (ALOX5AP), which is thought to potentiate ALOX5 synthetic activity. We hypothesized that T/HS results in the molecular association and nuclear colocalization of ALOX5 and ALOX5AP, which ultimately increases leukotriene production and potentiates lung injury. MATERIALS AND METHODS: To examine these molecular interactions, a rat T/HS model was used. Post-T/HS tissue was evaluated for lung injury through both histologic analysis of lung sections and biochemical analysis of bronchoalveolar lavage fluid. Lung tissue was immunostained for ALOX5 and ALOX5AP with association and colocalization evaluated by fluorescence resonance energy transfer. In addition, rats undergoing T/HS were treated with MK-886, a known ALOX5AP inhibitor. RESULTS: ALOX5 levels increase and ALOX5/ALOX5AP association occurred after T/HS, as evidenced by increases in total tissue fluorescence and fluorescence resonance energy transfer signal intensity, respectively. These findings coincided with increased leukotriene production and with the histological changes characteristic of lung injury. ALOX5/ALOX5AP complex formation, leukotriene production, and lung injury were decreased after inhibition of ALOX5AP with MK-886. CONCLUSIONS: These results suggest that the association of ALOX5/ALOX5AP contributes to leukotriene-induced inflammation and predisposes the T/HS animal to lung injury.

Case Report of Needle Disruption of the Retroperitoneal Lymph Nodes for Refractory Chylothorax After Double Lung Transplantation.

Chylothorax is a rare complication after double lung transplantation. We report a case of a 55-year-old man with idiopathic pulmonary fibrosis. He underwent a double lung transplantation with venoarterial extracorporeal membrane support. The surgery was uncomplicated; however, his postoperative course was complicated with a refractory chylothorax that started postoperative day 4. Medical management could not control the chylothorax, including nil per os, total parenteral nutrition, and octreotide administration. After failed percutaneous embolization via lymphangiography and surgical ligation of the thoracic duct and pleurodesis via video-assisted thoracoscopic surgery, percutaneous needle disruption of the retroperitoneal lymph nodes was performed. After this procedure, the chylothorax resolved quickly. Percutaneous needle disruption of the retroperitoneal lymph node is safe and effective for refractory chylothorax. This technique can be one of the main modalities to manage chylothorax after lung transplantation.

Impact of Multimodality Treatment Sequence on Survival in Stage IIB Non-Small Cell Lung Cancer.

BACKGROUND: The value of neoadjuvant treatment in combination with resection as multimodality therapy (MMT) for stage IIB non-small cell lung cancer remains controversial. METHODS: This was a national cohort study of patients with clinical stage IIB non-small cell lung cancer (2006 to 2015) that used the National Cancer Database. Cohorts were defined on the basis of the MMT sequence and were categorized as follows: surgery plus adjuvant chemotherapy (AC), surgery plus adjuvant chemoradiation (ACRT), neoadjuvant therapy plus surgery (NA), surgery-alone, and definitive chemotherapy or chemoradiation (nonsurgical). The primary comparison was between the NA and AC cohorts. Propensity matching methods were used to match cohorts who had AC vs NA. Multivariable Cox regression was used to analyze the difference in risk of death between the NA and AC groups. RESULTS: There were 10,841 patients with stage IIB lung cancer: 2476 in the AC, 854 with ACRT, 1195 with NA, 2019 with surgery alone, and 4297 with nonsurgical treatment. Of the 6544 patients who underwent surgery, 37.8% had AC, 13.1% had ACRT, 18.3% had NA, and 30.9% had surgery alone. Relative to those patients treated with AC, nonsurgical treatment (hazard ratio [HR], 2.92; 95% confidence interval [CI], 2.69 to 3.17) or surgery-alone (HR, 1.26; 95% CI, 1.14 to 1.38) was associated with a significantly higher risk of death. After propensity matching, there was no difference in the risk of death between the NA and AC cohorts (HR, 1.07; 95% CI, 0.88 to 1.31). CONCLUSIONS: MMT, including surgical resection, is associated with improved OS, regardless of treatment sequence, with no difference in survival on the basis of an NA or AC approach. The potential benefits of NA over AC to ensure that patients complete MMT warrant further prospective investigation.

Fixed or Weight-Tiered Enoxaparin After Thoracic Surgery for Venous Thromboembolism Prevention.

BACKGROUND: Venous thromboembolism is an important patient safety issue in thoracic surgery patients. The optimal enoxaparin dose remains unclear. This multicenter pre/post clinical trial compared the pharmacokinetics of fixed versus weight-tiered enoxaparin, and their impact on 90-day venous thromboembolism and bleeding. METHODS: Thoracic surgery patients were prospectively enrolled using a pre/post study design. Cohort 1 received enoxaparin 40 mg daily, and cohort 2 received a weight-tiered regimen: less than 70 kg received 30 mg daily; 70 kg to 89.9 kg received 40 mg once daily; and 90 kg or more received 50 mg daily. The primary study outcome was peak anti-factor Xa levels in response to fixed or weight-tiered enoxaparin. Secondary outcomes included trough anti-factor Xa, 90-day symptomatic venous thromboembolism, and 90-day clinically relevant bleeding. RESULTS: One hundred thirty-one patients were prospectively enrolled, including 65 in the fixed-dose cohort and 66 in the weight-tiered cohort. No patient was lost to follow-up. Weight-tiered enoxaparin was not significantly more likely to produce adequate anticoagulation (peak anti-factor Xa 0.3 IU/mL or greater) when compared with fixed-dose enoxaparin (44.3% vs 48.2%, P = .67). Weight-tiered enoxaparin was not more likely to avoid over-anticoagulation (peak anti-factor Xa 0.5 IU/mL or greater) when compared with fixed-dose enoxaparin (3.3% vs 3.6%, P = 1.00). The groups had no significant difference in trough anti-factor Xa. Observed rates of 90-day symptomatic venous thromboembolism and clinically relevant bleeding were low (0% and 3.1%, respectively) and were not significantly different between groups. CONCLUSIONS: This multicenter pre/post clinical trial did not show a pharmacokinetic advantage to weight-tiered enoxaparin, when compared with fixed-dose enoxaparin, in thoracic surgery patients. (Clinicaltrials.gov identifier: NCT03251963.).

Clinical-Pathologic Correlation and Guideline Concordance in Resectable Non-Small Cell Lung Cancer.

BACKGROUND: Accurate staging of non-small cell lung cancer (NSCLC) is critical for identifying patients who will benefit from multimodality therapy. This study evaluated clinical-pathologic correlation and its effects on receipt of guideline-concordant therapy in a national cohort. METHODS: A retrospective cohort study of patients with surgically resected NSCLC in the National Cancer Database (NCDB) between 2004 and 2014 was conducted. Primary tumor and nodal staging information was analyzed in patients who underwent upfront surgery and neoadjuvant therapy to calculate correlation between clinical and pathologic stages and estimate downstaging rate. Staging accuracy and Spearman's rank correlation coefficients were calculated. Multivariable Cox regression was used to evaluate the association between receipt of guideline-concordant therapy and overall risk of death. RESULTS: Among 82,999 patients, correlation between clinical and pathologic stages was strong (r = 0.69). Correlation of primary tumor staging was high (71.2%-84.5%). The positive predictive value of nodal staging was 78.2%. Neoadjuvant therapy was associated with downstaging in tumor stage (T1, 1.5%; T2, 22.6%; T3, 28%; T4, 42%) and 17.3% of positive nodes. Patients with stage I disease had high rates of guideline-concordant treatment (IA, 97.4%; and IB, 97.9%). Patients with stage IIA to IIIA disease had lower rates of guideline concordance. Receipt of guideline-concordant care was associated with a significantly lower risk of death (hazard ratio, 0.84; 95% confidence interval, 0.80-0.87). CONCLUSIONS: Clinical staging modalities are reasonably accurate. However, less than one half of patients with stage IIA to IIIA NSCLC receive guideline-concordant therapy, and this deficiency is associated with inferior survival. Identifying factors contributing to these differences is crucial to improve outcomes.

Antiproliferative agents alter vascular plasminogen activator inhibitor-1 expression: a potential prothrombotic mechanism of drug-eluting stents.

OBJECTIVE: Drug eluting stents (DES) reduce the incidence of restenosis after coronary angioplasty. Enthusiasm has been tempered by a possible increased risk of in-stent thrombosis. We examined the effects of paclitaxel and rapamycin on the endothelial transcriptome to identify alterations in gene expression associated with thrombosis. METHODS AND RESULTS: Gene expression profiling was performed on human coronary artery endothelial cells treated with rapamycin or paclitaxel. Plasminogen activator inhibitor-1 (PAI-1) was the most consistently induced transcript in rapamycin-treated human coronary artery endothelial cells. RT-PCR and ELISA were performed to confirm positive findings. Transgenic mice engineered to express enhanced green fluorescent protein under control of the human PAI-1 promoter were also treated. Rapamycin and paclitaxel treated endothelial cells produced dose-dependent increases in PAI-1. There was a variable effect on endothelial tissue-type plasminogen activator (t-PA) expression. Enhanced expression of PAI-1 and enhanced green fluorescent protein were detected in coronary arteries, the aorta, and kidney of the mice. CONCLUSIONS: Antiproliferative agents stimulate the expression of prothrombotic genes. PAI-1 expression may also play a role in the prevention of restenosis through an antimigratory mechanism. The effects of antiproliferatives on vascular gene expression deserve further scrutiny in view of the increasing utilization of drug-eluting stents.

Impact of insurance status on receipt of definitive surgical therapy and posttreatment outcomes in early stage lung cancer.

BACKGROUND: The impact of insurance on outcomes in the modern era of evidence-based guidelines is unclear. We sought to examine differences in receipt of therapy and outcomes for early stage, non-small cell lung cancer patients by insurance coverage. METHOD: Clinical T1-3 N0-1 non-small cell lung cancer cases were identified in the 2004 to 2014 National Cancer Database and compared across 4 groups: private, Medicare, Medicaid, and uninsured. A multivariable, linear regression model was used to examine the effects of insurance status on time to curative surgical therapy, adjusting for patient and facility characteristics. Receipt of different therapies was examined with multivariable logistic regression. Survival analysis was conducted with Cox regression. RESULTS: A total of 240,361 patients presented with early stage non-small cell lung cancer (60,532 private, 164,377 Medicare, 11,001 Medicaid, and 4,451 uninsured). After adjustment, Medicaid and uninsured patients received surgical therapy later than privately insured patients (9.5 days and 7.0 days, respectively, P < .001), were more likely to be delayed > 8 weeks (odds ratio 1.64, 95% confidence interval 1.55-1.73 and odds ratio 1.46, 95% confidence interval 1.34-1.58), and were significantly less likely to receive surgery (odds ratio 0.53, 95% confidence interval 0.50-0.56 and odds ratio 0.50, 95% confidence interval 0.47-0.55). Uninsured patients were more likely to receive no treatment (odds ratio 2.15, 95% confidence interval 1.92-2.41), followed by Medicaid patients (odds ratio 1.66, 95% confidence interval 1.53-1.80). The 5-year overall survival was significantly worse in the Medicaid and uninsured populations. CONCLUSION: Even in the modern era, uninsured and Medicaid early stage non-small cell lung cancer patients have decreased odds of receiving a potentially curative operation and experience inferior outcomes. Given substantial expenditures on the Medicaid program, strategies for increasing utilization of curative surgery in Medicaid patients with lung cancer are needed.

Prospective study of giant paraesophageal hernia repair with 1-year follow-up.

OBJECTIVE: Evaluating giant paraesophageal hernia (GPEH) repair requires long-term follow-up. GPEH repair can have associated high recurrence rates, yet this incidence depends on how recurrence is defined. Our objective was to prospectively evaluate patients undergoing GPEH repair with 1-year follow-up. METHODS: Patients undergoing elective GPEH repair between 2011 and 2014 were enrolled prospectively. Postoperatively, patients were evaluated at 1 month and 1 year. Radiographic recurrence was evaluated by barium swallow and defined as a gastroesophageal junction located above the hiatus. Quality of life was evaluated pre- and postoperatively with the use of a validated questionnaire. RESULTS: One-hundred six patients were enrolled. The majority of GPEH repairs were performed laparoscopically (80.2%), and 7.5% were redo repairs. At 1-year follow-up, 63.4% of patients were symptom free, and radiographic recurrence was 32.7%. Recurrence rate was 18.8% with standard definition (>2 cm of stomach above the diaphragm). Quality of life scores at 1 year were significantly better after operative repair, even in patients with radiographic recurrence (7.0 vs 22.5 all patients, 13.0 vs 22.5 with recurrence; P < .001). Patients with small radiographic recurrences have similar satisfaction and symptom severity to patients with >2 cm recurrences. CONCLUSIONS: GPEH repair can be performed with low operative mortality and morbidity. The rate of recurrence at 1 year depends on the definition used. Patient satisfaction and symptom severity are similar between patients with radiographic and greater than 2 cm hernia recurrences. Longer follow-up and critical assessment of our results are needed to understand the true impact of this procedure and better inform perioperative decision making.

Exploring ethical conflicts in emergency trauma research: the COMBAT (Control of Major Bleeding after Trauma) study experience.

BACKGROUND: Up to 25% of severely injured patients develop trauma-induced coagulopathy. To study interventions for this vulnerable population for whom consent cannot be obtained easily, the Food and Drug Administration issued regulations for emergency research with an exception from informed consent (ER-EIC). We describe the community consultation and public disclosure (CC/PD) process in preparation for an ER-EIC study, namely the Control Of Major Bleeding After Trauma (COMBAT) study. METHODS: The CC/PD was guided by the four bioethical principles. We used a multimedia approach, including one-way communications (newspaper ads, brochures, television, radio, and web) and two-way communications (interactive in-person presentations at community meetings, printed and online feedback forms) to reach the trials catchment area (Denver County's population: 643,000 and the Denver larger metro area where commuters reside: 2.9 million). Particular attention was given to special-interests groups (eg, Jehovah Witnesses, homeless) and to Spanish-speaking communities (brochures and presentations in Spanish). Opt-out materials were available during on-site presentations or via the COMBAT study website. RESULTS: A total of 227 community organizations were contacted. Brochures were distributed to 11 medical clinics and 3 homeless shelters. The multimedia campaign had the potential to reach an estimated audience of 1.5 million individuals in large metro Denver area, the majority via one-way communication and 1900 in two-way communications. This resource intensive process cost more than $84,000. CONCLUSION: The CC/PD process is resource-intensive, costly, and complex. Although the multimedia CC/PD reached a large audience, the effectiveness of this process remains elusive. The templates can be helpful to similar ER-EIC studies.

Combat: Initial Experience with a Randomized Clinical Trial of Plasma-Based Resuscitation in the Field for Traumatic Hemorrhagic Shock.

The existing evidence shows great promise for plasma as the first resuscitation fluid in both civilian and military trauma. We embarked on the Control of Major Bleeding After Trauma (COMBAT) trial with the support of the Department of Defense to determine if plasma-first resuscitation yields hemostatic and survival benefits. The methodology of the COMBAT study represents not only 3 years of development work but also the integration of nearly two decades of technical experience with the design and implementation of other clinical trials and studies. Herein, we describe the key features of the study design, critical personnel and infrastructural elements, and key innovations. We will also briefly outline the systems engineering challenges entailed by this study. The COMBAT trial is a randomized, placebo-controlled, semiblinded, prospective, phase IIB clinical trial conducted in a ground ambulance fleet based at a level I trauma center and part of a multicenter collaboration. The primary objective of the COMBAT trial is to determine the efficacy of field resuscitation with plasma first compared with standard of care (normal saline). To date, we have enrolled 30 subjects in the COMBAT study. The ability to achieve intervention with a hemostatic resuscitation agent in the closest possible temporal proximity to injury is critical and represents an opportunity to forestall the evolution of the "bloody vicious cycle." Thus, the COMBAT model for deploying plasma in first-response units should serve as a model for randomized clinical trials of other hemostatic resuscitative agents.

A principal component analysis of postinjury viscoelastic assays: clotting factor depletion versus fibrinolysis.

INTRODUCTION: The mechanisms driving trauma-induced coagulopathy (TIC) remain to be defined, and its therapy demands an orchestrated replacement of specific blood products. Thrombelastography (TEG) is a tool to guide the TIC multicomponent therapy. Principal component analysis (PCA) is a statistical approach that identifies variable clusters; thus, we hypothesize that PCA can identify specific combinations of TEG-generated values that reflect TIC mechanisms. METHODS: Adult trauma patients admitted from September 2010 to October 2013 for whom a massive transfusion protocol was activated were included. Rapid TEG values obtained within the first 6 hours after injury were included in the PCA. PCA components with an eigenvalue >1 were retained, and, within components, variable loadings (equivalent to correlation coefficients) >|60| were considered significant. Component scorings for each patient were calculated and clinical characteristics of patients with high and low scores were compared. RESULTS: Of 98 enrolled patients, 67% were male and 70% suffered blunt trauma. Median age was 41 years (interquartile range 28-55) and median Injury Severity Score was 31.5 (interquartile range 24-43). PCA identified three principal components (PCs) that together explained 93% of the overall variance. PC1 reflected global coagulopathy with depletion of platelets and fibrinogen whereas PC3 indicated hyperfibrinolysis. PC2 may represent endogenous anticoagulants such as the activation of protein C. CONCLUSION: PCA suggests depletion coagulopathy is independent from fibrinolytic coagulopathy. Furthermore, the distribution of mortality suggests that low levels of fibrinolysis may be beneficial in a select group of injured patients. These data underscore the potential of risk for concurrent presumptive treatment for preserved depletion coagulopathy and possible fibrinolysis.

Mesenteric lymph diversion abrogates 5-lipoxygenase activation in the kidney following trauma and hemorrhagic shock.

BACKGROUND: Early acute kidney injury (AKI) following trauma is associated with multiorgan failure and mortality. Leukotrienes have been implicated both in AKI and in acute lung injury. Activated 5-lipoxygenase (5-LO) colocalizes with 5-LO-activating protein (FLAP) in the first step of leukotriene production following trauma and hemorrhagic shock (T/HS). Diversion of postshock mesenteric lymph, which is rich in the 5-LO substrate of arachidonate, attenuates lung injury and decreases 5-LO/FLAP associations in the lung after T/HS. We hypothesized that mesenteric lymph diversion (MLD) will also attenuate postshock 5-LO-mediated AKI. METHODS: Rats underwent T/HS (laparotomy, hemorrhagic shock to a mean arterial pressure of 30 mm Hg for 45 minutes, and resuscitation), and MLD was accomplished via cannulation of the mesenteric duct. Extent of kidney injury was determined via histology score and verified by urinary neutrophil gelatinase-associated lipocalin assay. Kidney sections were immunostained for 5-LO and FLAP, and colocalization was determined by fluorescence resonance energy transfer signal intensity. The end leukotriene products of 5-LO were determined in urine. RESULTS: AKI was evident in the T/HS group by derangement in kidney tubule architecture and confirmed by neutrophil gelatinase-associated lipocalin assay, whereas MLD during T/HS preserved renal tubule morphology at a sham level. MLD during T/HS decreased the associations between 5-LO and FLAP demonstrated by fluorescence resonance energy transfer microscopy and decreased leukotriene production in urine. CONCLUSION: 5-LO and FLAP colocalize in the interstitium of the renal medulla following T/HS. MLD attenuates this phenomenon, which coincides with pathologic changes seen in tubules during kidney injury and biochemical evidence of AKI. These data suggest that gut-derived leukotriene substrate predisposes the kidney and the lung to subsequent injury.

Fibrinolysis greater than 3% is the critical value for initiation of antifibrinolytic therapy.

BACKGROUND: The acute coagulopathy of trauma is present in up to one third of patients by the time of admission, and the recent CRASH-2 and MATTERs trials have focused worldwide attention on hyperfibrinolysis as a component of acute coagulopathy of trauma. Thromboelastography (TEG) is a powerful tool for analyzing fibrinolyis, but a clinically relevant threshold for defining hyperfibrinolysis has yet to be determined. Recent data suggest that the accepted normal upper bound of 7.5% for 30-minute fibrinolysis (LY30) by TEG is inappropriate in severe trauma, as the risk of death rises at much lower levels of clot lysis. We wished to determine the validity of this hypothesis and establish a threshold value to treat fibrinolysis, based on prediction of massive transfusion requirement and risk of mortality. METHODS: Patients with uncontrolled hemorrhage, meeting the massive transfusion protocol (MTP) criteria at admission (n = 73), represent the most severely injured trauma population at our center (median Injury Severity Score [ISS], 30; interquartile range, 20-38). Citrated kaolin TEG was performed at admission blood samples from this population, stratified by LY30, and evaluated for transfusion requirement and 28-day mortality. The same analysis was conducted on available field blood samples from all non-MTP trauma patients (n = 216) in the same period. These represent the general trauma population. RESULTS: Within the MTP-activating population, the cohort of patients with LY30 of 3% or greater was shown to be at much higher risk for requiring a massive transfusion (90.9% vs. 30.5%, p = 0.0008) and dying of hemorrhage (45.5% vs. 4.8%, p = 0.0014) than those with LY30 less than 3%. Similar trends were seen in the general trauma population. CONCLUSION: LY30 of 3% or greater defines clinically relevant hyperfibrinolysis and strongly predicts the requirement for massive transfusion and an increased risk of mortality in trauma patients presenting with uncontrolled hemorrhage. This threshold value for LY30 represents a critical indication for the treatment of fibrinolysis. LEVEL OF EVIDENCE: Prognostic study, level III.

Isoflurane prevents acute lung injury through ADP-mediated platelet inhibition.

BACKGROUND: Growing evidence suggests platelets are essential in posttraumatic, acute lung injury (ALI). Halogenated ethers interfere with the formation of platelet-granulocyte aggregates. The potential benefit of halogenated ethers has not been investigated in models of trauma/hemorrhagic shock (T/HS). Therefore, we hypothesized that isoflurane decreases T/HS-mediated ALI through platelet inhibition. METHODS: Sprague-Dawley rats (n = 47) were anesthetized by either pentobarbital or inhaled isoflurane and placed into (1) control, (2) trauma (laparotomy) sham shock, (3) T/HS (mean arterial pressure, 30 mmHg × 45 min), (4) pretreatment with an ADP receptor antagonist, or (5) T/HS with isoflurane initiated during resuscitation groups. ALI was determined by protein and pulmonary immunofluorescence bronchoalveolar lavage (BAL) fluid. Platelet Mapping specifically evaluated thrombin-independent inhibition of the ADP and AA pathways of platelet activation. RESULTS: Pretreatment with isoflurane abrogated ALI as measured by both BAL fluid protein and pulmonary immunofluorescence (P < .001). Platelet Mapping revealed specific inhibition of the platelet ADP-pathway with isoflurane (P < .001). Pretreatment with an ADP receptor antagonist decreased ALI to sham levels, confirming that specific platelet ADP inhibition decreases ALI. Isoflurane initiated during resuscitation also decreased ALI (P < .001). CONCLUSION: Isoflurane attenuates ALI through an antiplatelet mechanism, in part, through inhibition of the platelet ADP pathway. Isoflurane given postinjury also protects against ALI, and highlights the potential applications of this therapy in various clinical scenarios of ischemia/reperfusion.

Pivotal role of PAI-1 in a murine model of hepatic vein thrombosis.

Hepatic veno-occlusive disease (VOD) is a common complication of high-dose chemotherapy associated with bone marrow transplantation. While the pathogenesis of VOD is uncertain, plasminogen activator inhibitor-1 (PAI-1) has emerged as a diagnostic marker and predictor of VOD in humans. In this study, we investigated the role of PAI-1 in a murine model of VOD produced by long-term nitric oxide synthase inhibition using L-NAME. After 6 weeks, wild-type (WT) mice developed extensive fibrinoid hepatic venous thrombi and biochemical evidence of hepatic injury and dysfunction. In contrast, PAI-1-deficient mice were largely protected from the development of hepatic vein thrombosis. Furthermore, WT mice that received tiplaxtinin, an antagonist of PAI-1, were effectively protected from L-NAME-induced thrombosis. Taken together, these data indicate that NO and PAI-1 play pivotal and antagonistic roles in hepatic vein thrombosis and that PAI-1 is a potential target in the prevention and treatment of VOD in humans.