Multimodality treatment for grade V hepatic injuries: perihepatic packing, arterial embolization, and venous stenting.
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Biomedical subjects
Publications and source records attributed to E E Moore.
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BACKGROUND: Evaluating blunt abdominal trauma remains a resource intensive aspect of trauma care. Recently, emergency department ultrasound has been promulgated as a noninvasive diagnostic alternative. Consequently, we hypothesized that an ultrasound based key clinical pathway (KCP) would reduce the number of diagnostic peritoneal lavage (DPL) and computed tomographic (CT) scans required to evaluate blunt abdominal trauma without increased risk to the patient. METHODS: This study was a prospective analysis of patients evaluated for blunt abdominal trauma during a 3-month period using this KCP compared with a 3-month historical cohort. RESULTS: Data were collected for 486 KCP patients and were compared with 516 patients in the study cohort. No differences were noted regarding demographics, number of laparotomies, or type of injuries. Using the KCP, DPL was reduced from 17 to 4%, and computed tomography from 56 to 26%. Furthermore, the injury severity score increased from 11.6 to 21.5 for DPL patients and from 4.6 to 8.3 for computed tomography patients. Ultrasound exams were used exclusively in 65% of patients. CONCLUSIONS: An ultrasound based KCP resulted in significant reductions in the use of invasive DPL and costly CT scanning in the evaluation of blunt abdominal trauma without risk to the patient.
BACKGROUND: Partial left heart bypass is widely used in the repair of traumatic aortic disruptions. We recently encountered two patients with posterior circulation infarctions after repair of traumatic aortic disruptions using heparin-less partial left heart bypass. METHODS/RESULTS: Both patients underwent interposition graft repair of thoracic aortic transections at the level of the isthmus. The first patient developed a left posterior inferior cerebellar artery infarct after a clamp time of 44 minutes. Swelling of this infarct necessitated ventriculostomy placement. The second patient developed a pontine infarct postoperatively after a cross-clamp time of 56 minutes and suffered a persistent left upper extremity paresis. CONCLUSIONS: Partial left heart bypass may have predisposed these two patients to clamp-related embolic events via the left vertebral artery. This experience warrants further surveillance to detect these infarcts which can require neurosurgical intervention. Additionally, the events suggest reconsideration of systemic anticoagulation during aortic cross-clamp times exceeding 30 minutes.
BACKGROUND: The pathogenesis of multiple organ failure after injury is believed to involve priming and activation of the inflammatory cascade, and the polymorphonuclear neutrophil (PMN) appears to be an integral effector. Characterization of the primed PMN is evolving. Because much research has focused on the respiratory burst, the synergistic role of cytotoxic proteases, especially elastase, has been largely ignored. In addition, CD11b has been identified as pivotal in PMN-mediated tissue injury. Our hypothesis is that the well-recognized postinjury mediators platelet-activating factor (PAF) and leukotriene B4 (LTB4) prime PMNs for the concordant release of elastase and superoxide (O2-) as well as for CD11b up-regulation. METHODS: Human PMNs were isolated and then incubated with PAF or LTB4 before N-formyl-methionyl-leucyl-phenylalanine activation. O2- generation was measured by reduction of cytochrome c. Elastase was measured by cleavage of Ala-Ala-Pro-Val p-nitroanilide. CD11b expression was quantified by incubation with R-phycoerythrin-labeled monoclonal antibodies followed by flow cytometry. RESULTS: PAF and LTB4 primed PMNs maximally within 5 minutes for the production of O2-, elastase release, and simultaneous up-regulation of CD11b expression on the PMN surface. CONCLUSION: PAF and LTB4 prime human PMNs for the concordant release of elastase, generation of O2-, and CD11b up-regulation. Understanding the physiologic characteristics of PMN priming may offer new therapeutic targets to avoid the development of multiple organ failure after injury.
We have previously documented the safety of 1 unit (50 gram) of human polymerized hemoglobin (Poly SFH-P) in healthy volunteers. This report describes the first patient trial to assess the therapeutic benefit of Poly SFH-P in acute blood loss. Thirty-nine patients received 1 (n = 14), 2 (n = 2), 3 (n = 15), or 6 (n = 8) units of Poly SFH-P instead of red cells as part of their blood replacement after trauma and urgent surgery. There were no safety issues related to the infusion of Poly SFH-P. The plasma hemoglobin concentration ([Hb]) after the infusion of 6 units (300 gram) of Poly SFH-P was 4.8 +/- 0.8 g/dL (mean +/- SD). Although the red cell [Hb] fell to 2.9 +/- 1.2 g/dL, the total [Hb] was maintained at 7.5 +/- 1.2 g/dL. Poly SFH-P maintained total [Hb], despite the marked fall in red cell [Hb] due to blood loss. The utilization of O2 (extraction ratio) was 27 +/- 16% from the red cells and 37 +/- 13% from the Poly SFH-P. Twenty-three patients (59%) avoided allogeneic transfusions during the first 24 hours after blood loss. Poly SFH-P effectively loads and unloads O2 and maintains total hemoglobin in lieu of red cells after acute blood loss, thereby reducing allogeneic transfusions. Poly SFH-P seems to be a clinically useful blood substitute.
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Our basic laboratory work has identified the postischemic gut as a source of platelet-activating factor (PAF), which primes circulating neutrophils for the production of reactive oxygen metabolites (ROMs) leading to distant organ injury. Circulating PAF-acetylhydrolase (PAF-AH) hydrolyzes PAF to lyso-PAF. Recently, ROMs have been shown to rapidly and irreversibly inactivate human PAF-AH. Consequently, our study hypothesis was that reduced levels of PAF-AH in severely injured patients would be associated with the development of multiple organ failure (MOF). Over a 16 mo period, 26 patients at known risk for MOF (Injury Severity Score (ISS) > or = 25 or an ISS > 15 with > or = 6 U of blood transfused within the first 6 h) had blood sampled on postinjury days 0, 1, 2, 3, and 5. PAF-AH activity was assessed by measuring the percentage of 3H-labeled PAF hydrolyzed. MOF was defined by a standard score. The mean age of the 26 study patients was 34 +/- 2 yr; 19 (73%) were male. The injury mechanism was blunt in 18 (69%), and the mean ISS was 31 +/- 2. Eight patients (31%) developed MOF. In the MOF patients, plasma PAF-AH activity was significantly lower on the day of injury and remained depressed throughout the ensuing 5 days compared with the non-MOF patients. Reduced PAF-AH activity is associated with the development of postinjury MOF. With the recent molecular cloning of human plasma PAF-AH, repleting this circulating, anti-inflammatory enzyme may represent useful therapy for these high risk patients.
We investigated serum ferritin levels as a predictor of the acute respiratory distress syndrome (ARDS) because: (1) proinflammatory cytokines, which are implicated in ARDS, increase ferritin synthesis; and (2) oxidative stress in patients at risk for ARDS might liberate iron from ferritin, accelerating toxic hydroxyl radical (.OH) formation. Serum ferritin levels measured by radioimmunoassay (RIA) were greater in 75 patients at risk for ARDS (women, p < 0.0001; men, p < 0.0001) and 8 patients with ARDS (women, p = 0.001; men, p = 0.0009) than in healthy control subjects. Serum ferritin levels were also greater in female (p = 0.003) and male (p = 0.003) at-risk patients who developed ARDS than in patients who did not develop ARDS. In women, a value exceeding 270 ng/ml predicted ARDS with an 83% sensitivity, 71% specificity, 67% positive, and 86% negative predictive value. In men, a value exceeding 680 ng/ml predicted ARDS with a 60% sensitivity, 90% specificity, 75% positive, and 82% negative predictive value. Serum ferritin levels did not correlate with C-reactive protein levels, were not different in medical or surgical at-risk patients, and were not accounted for by liver disease. Evaluating serum ferritin levels in at-risk patients may help predict the development of ARDS and thereby improve study and treatment of ARDS. Elevated serum ferritin levels may also regulate the participation of iron in the oxidative responses that contribute to ARDS.
Although numerous cytokines, including interleukin (IL)-1, IL-8, and tumor necrosis factor, circulate in critically ill patients at risk for acute respiratory distress syndrome (ARDS), none clearly predict the development of the syndrome. We hypothesized that cytokines, such as IL-1ra, IL-10, and IL-4, which modulate inflammation, might contribute to or reflect the development of acute lung injury. Accordingly, serial levels of IL-1ra and IL-10 were measured in 77 patients who were identifed as being at risk for the development of ARDS. Initial IL-1ra levels were significantly higher (p < 0.0001) in the patients (7.82 [2.29-38.01] ng/ml) than in normal control subjects (0.24 [0.24-0.34] ng/ml) but did not predict the development of ARDS. Initial IL-1ra levels, however, were greater (p = 0.038) in the patients who died (31.95 [3.02-65.06] ng/ml) compared with survivors (6.61 [1.86-29.33] ng/ml). Similarly, IL-10 levels were increased in patients (155 [53.75-318.75] ng/ml) compared with normal control subjects (0 ng/ml) but did not predict the development of ARDS. Like IL-1ra levels, initial IL-10 levels were significantly higher (p = 0.005) in patients who died compared with survivors. IL-4 was not detectable in any of the patient plasma samples measured. Thus, modulators of inflammation are increased in patients at risk for ARDS who die, but do not predict the development of the syndrome.
The calcitonin receptor is a seven-transmembrane G-protein coupled receptor which is located on osteoclasts, in kidney, and in brain. The receptor signals through multiple pathways, including activation of adenylate cyclase, leading to inhibition of bone resorption. In the present study, we used antibodies raised against the C-terminus of the human calcitonin (CT) receptor to study receptor phosphorylation. In baby hamster kidney cells transfected with the human CT receptor, phosphorylation of the receptor increased approximately 2.5-fold after cells were treated with calcitonin, phorbol ester, forskolin, or calcitonin plus phorbol ester. Phosphorylation reached a maximum 20 minutes after treatment with sCT and half-maximal phosphorylation was observed at 0.1 nM sCT, a hormone concentration related to receptor occupancy. Digestion of the immunoprecipitated receptor with cyanogen bromide (CNBr) yielded a single 32P-labeled fragment which migrates at Mr 14 kD on gel electrophoresis. This corresponds to the predicted size of the CNBr fragment containing the C-terminal domain of the receptor. No 32P-labeled bands were observed for CNBr fragments predicted to contain the first, second, or third intracellular loops. An identical labeling pattern was seen with cells expressing an alternatively spliced isoform of the human receptor (insert-positive isoform). Phosphorylation of the receptor by phorbol ester and forskolin was further localized to a Mr 6 kD proteolytic fragment within the C-terminus. The protein kinase A and C inhibitors staurosporine, chelerythrine, and H-89 had little effect on CT-induced phosphorylation, suggesting that nonsecond messenger-activated kinases are involved in hormone-dependent CT receptor phosphorylation.
OBJECTIVE: To determine if blood transfusion is a consistent risk factor for postinjury multiple organ failure (MOF), independent of other shock indexes. DESIGN: A 55-month inception cohort study ending on August 30, 1995. Data characterizing postinjury MOF were prospectively collected. Multiple logistic regression analysis was performed on 5 sets of data. Set 1 included admission data (age, sex, comorbidity, injury mechanism, Glasgow Coma Scale, Injury Severity Score, and systolic blood pressure determined in the emergency department) plus the amount of blood transfused within the first 12 hours. In the subsequent 4 data sets, other indexes of shock (early base deficit, early lactate level, late base deficit, and late lactate level) were sequentially added. Additionally, the same multiple logistic regression analyses were performed with early MOF and late MOF as the outcome variables. SETTING: Denver General Hospital, Denver, Colo, is a regional level I trauma center. PATIENTS: Five hundred thirteen consecutive trauma patients admitted to the trauma intensive care unit with an Injury Severity Score greater than 15 who were older than 16 years and who survived longer than 48 hours. INTERVENTIONS: None. MAIN OUTCOME MEASURES: The relationship of blood transfusions and other shock indexes with the outcome variable, MOF. RESULTS: A dose-response relationship between early blood transfusion and the later development of MOF was identified. Despite the inclusion of other indexes of shock, blood transfusion was identified as an independent risk factor in 13 of the 15 multiple logistic regression models tested; the odds ratios were high, especially in the early MOF models. CONCLUSIONS: Blood transfusion is an early consistent risk factor for postinjury MOF, independent of other indexes of shock.
OBJECTIVE: To determine the effect of a history of chronic alcohol abuse on the incidence of acute respiratory distress syndrome (ARDS) and in-hospital mortality. DESIGN: Prospective cohort study. PATIENTS: A total of 351 medical and surgical intensive care unit patients with one of seven at-risk diagnoses for the development of ARDS. MAIN OUTCOME MEASURES: The development of ARDS and in-hospital mortality. RESULTS: Of the 351 patients enrolled in the study, the incidence of ARDS in patients with a history of alcohol abuse was significantly higher than in patients without a history of alcohol abuse (43% vs 22%) (P < .001; relative risk [RR], 1.98; 95% confidence interval [Cl], 1.32 to 2.85). In patients with sepsis, ARDS developed in 52% of the patients with a prior history of alcohol abuse compared with only 20% in patients without a history of alcohol abuse (P < .001; RR, 2.59; 95% Cl, 1.29 to 5.12). Fifty-one percent (52/102) of the patients who developed ARDS died compared with only 14% (36/249) of patients who did not develop ARDS (P < .001). In the subset of patients who developed ARDS, the in-hospital mortality rate was 65% in patients with a prior history of alcohol abuse. This mortality rate was significantly higher (P = .003) than the mortality rate in patients without a history of alcohol abuse (36%). CONCLUSIONS: A prior history of chronic alcohol abuse significantly increases the risk of developing ARDS in critically ill patients with an identified at-risk diagnosis. Our results may be useful in the earlier and more accurate identification of patients at high risk for developing ARDS.
BACKGROUND: Neutrophil (PMN) apoptosis promotes the phagocytosis of PMNs without inciting an inflammatory response or local cytotoxic effect. This is important in the normal resolution of inflammatory processes and the control of tissue injury. Conversely, a delay in PMN apoptosis may facilitate PMN-mediated organ dysfunction by extending PMN functional integrity at an inflammatory site. Elevated circulating and tissue levels of interleukin-6 (IL-6) have been associated with postinjury organ dysfunction, and IL-6 appears to augment PMN cytotoxic functions. Therefore, we hypothesized that IL-6 delays PMN apoptosis, thereby enhancing PMN-mediated cytotoxicity. METHODS: Neutrophils isolated from healthy human donors were incubated for 24 hours in enriched RPMI 1640 cell culture medium at 37 degrees C in 5% carbon dioxide. Subgroups were incubated with IL-6, heat-denatured IL-6, or buffer alone. Apoptosis was assessed morphologically using acridine orange-ethidium bromide stain, and biochemically by DNA gel electrophoresis. Functional capacity of PMNs was assessed by superoxide generation after activation with phorbol myristate acetate or platelet-activating factor plus formyl-methionyl-leucyl-phenylalanine. RESULTS: Treatment with IL-6 resulted in a greater population of surviving (nonapopototic) PMNs after 24 hours. In addition, the IL-6-treated population produced more superoxide after 24 hours than did the untreated or heat-denature IL-6-treated groups, after either activating stimulus. CONCLUSIONS: Interleukin-6 delays PMN apoptosis, resulting in a larger population of surviving PMNs with a greater collective capacity for superoxide production. This could potentially facilitate PMN-mediated tissue injury and may be a mechanism whereby IL-6 contributes to organ dysfunction.
Plasma from 33 patients at risk of multiple organ failure (MOF) after major trauma was tested for a priming effect on neutrophils, and for the presence of platelet-activating factor (PAF) activity and interleukin (IL) 8. Plasma sampled at 3, 6, 12 and 24 h after injury significantly primed normal neutrophils to release mean(s.e.m.) 1.26(0.19), 1.33(0.26), 1.04(0.14) and 0.86(0.13) nmol superoxide per min per 1.3 x 10(6) neutrophils respectively (P < 0.05). Priming at 3 h after injury was inhibited by mean(s.e.m.) 63.8(7.0) per cent by the PAF antagonist, WEB 2170 (P < 0.01). Mean(s.e.m.) plasma IL-8 was raised at 6 and 12 h after injury to 785(183) and 836(175) pg/ml (P < 0.01). At 12 h after injury the plasma IL-8 level correlated directly with the number of units of red blood cells transfused (r = 0.64, P < 0.01), and was significantly higher in the group of six patients who developed MOF (P < 0.05). These data suggest that after trauma the mediators PAF and IL-8 appear sequentially in the circulation, are potential mechanisms of circulating neutrophil priming, and that IL-8 may also be an early biochemical marker predicting the onset of MOF.
Interleukin-6 (IL-6) is an integral mediator of the acute phase response to injury and infection; an exaggerated IL-6 response has been associated with adverse clinical events. The precise role of IL-6 is unclear, but it appears capable of modulating the functional repertoire of mature neutrophils (PMNs). Our previous work demonstrated that IL-6 -stimulated PMNs are primed by lower concentrations of platelet-activating factor (PAF) than nonstimulated PMNs. Recently, we have found that IL-6 suppresses PMN apoptosis via a PAF-like mechanism. We hypothesized that IL-6 stimulates PMNs to produce PAF. PMNs isolated from healthy human donors were incubated with IL-6 (0.1-100 ng/ml) at 37 degrees C. Lipid production was measured by use of thin-layer chromatography, and PAF quantitated with a scintillation proximity assay. IL-6 (1 and 10 ng/ml) stimulated PMNs to produce increase quantities of PAF. PAF production was associated with an increase in PMN cytosolic calcium. These data may provide mechanistic insight into IL-6 regulation of PMN-mediated cytotoxicity and the role of PAF in mediating IL-6 effects on PMNs.
Our previous in vivo studies have implicated phospholipase A2 activation and platelet-activating factor (PAF) production as an important mediator of neutrophil (PMN) priming after mesenteric ischemia/reperfusion. Furthermore, our in vitro studies demonstrate that PAF priming of PMN enhances PMN respiratory burst and increases PMN adherence to human umbilical vein endothelial cell cultures (HUVEC). Others have shown that cytokine stimulated HUVEC can activate quiescent PMNs to provoke endothelial cell (EC) monolayer disruption via EC detachment by a noncytolytic PMN protease mechanism. Hypoxia and reoxygenation (H/R) of HUVEC can also directly stimulate PAF production. Consequently, we hypothesized that HUVEC H/R can activate quiescent PMNs to disrupt the EC monolayer (detachment) through a PAF mediated mechanism. HUVEC were labeled with 51 chromium (51Cr) and subjected to 45 min hypoxia (95% N2/5% CO2). PMNs freshly isolated by Percoll gradient centrifugation were added to HUVEC and reoxygenated for 120 min. Additionally, H/R HUVEC with PMN pretreated with WEB2170 (a PAF receptor antagonist) was compared to control (non-H/R HUVEC incubated with PMNs). Wells were washed at end incubation, and adherent ECs counted. Detachment = [total counts - sample counts]/total counts X 100. H/R HUVEC plus PMN provoked a 29.3 +/- 1.6% detachment of EC compared to 9.3 +/- 2.9% detachment in control (non-H/R HUVEC with PMNs). In contrast, H/R HUVEC with PMNs preincubated with WEB2170 had 9.9 +/- 3.8% detachment of EC. In summary, HUVEC H/R activated quiescent PMNs to disrupt an EC monolayer (detachment) via a PAF mechanism.
Elevated levels of soluble intercellular adhesion molecule-1 have been shown predictive of post-injury multiple organ failure. We hypothesized that sICAM-1 augments distant organ injury via its affect on the PMN and; thus, have examined neutrophil elastase and superoxide production in response to sICAM-1. To obtain soluble ICAM-1, Chinese Hamster Ovarian (CHO) cells were transfected with human ICAM-1 (cDNA vector CD1.8), lysed and centrifuged at 150,000g for 1 hr; supernatant was passed over an ICAM-1 affinity gradient, eluted with 0.1 mM glycine x HCl, and concentrated using an Amicon Spin-X filter. PMNs were incubated for 1 hr with sICAM-1 at 37 degrees C. Quiescent and PMA-activated PMNs served as negative and positive controls respectively. Elastase activity was measured by the cleavage of methoxy-succinyl-alalyl-alalyl-prolyl-valyl-p-nitroanilide. Superoxide production was determined by superoxide dismutase inhibitive ferricytochrome C reduction over a 5-60 min incubation. PMN incubation with sICAM-1 provoked marked increase in elastase release 10.43 +/- 2.90 (10(-6) U/hr) compared to control 1.64 +/- 0.57, and was equivalent to PMA-activated PMN elastase release 11.60 +/- 1.50 (10(-6) U/hr). In contrast, sICAM-1 alone did not promote spontaneous PMN superoxide production beyond buffer treated PMNs (0.25 +/- 0.09 nmole/2.5 x 10(5) PMN/min). In sum, sICAM-1 stimulates PMN elastase release in vitro. Clinically, this may represent a mechanism by which sICAM-1 participates in the genesis of post-injury multiple organ failure.
Nitric oxide (NO.) has proven effective in improving oxygenation and reducing pulmonary hypertension in the acute respiratory distress syndrome (ARDS), but the precise mechanism remains unclear. NO. has been shown to reduce leukocyte-endothelial adhesion, attenuate neutrophil (PMN) sequestration, and protect endothelium from an inflammatory insult. Intercellular adhesion molecule (ICAM)-1 is a pivotal regulator of PMN-endothelial adhesion and, thus, a critical mediator of PMN cytotoxicity. Consequently, we hypothesized that NO. suppresses ICAM-1 expression on endothelium. Human umbilical vein endothelial cells (HUVEC) were cultured. The NO. donor 3-morpholinosidnonimine (SIN-1) (0.1-10 microM) was incubated with HUVEC for 4 hr. In separate experiments, HUVEC were incubated with bacterial lipopolysaccharide (LPS) (100 ng/ml) alone or following SIN-1 pretreatment. ICAM-1 expression on HUVEC was measured by flow cytometric analysis. SIN-1 (1 and 10 microM) reduced the expression of ICAM-1 on resting HUVEC by 58 and 47%, respectively. LPS upregulated ICAM-1 expression; however, this was not affected by SIN-1 pretreatment. We conclude that NO. reduces constitutive endothelial expression of ICAM-1, but does not prevent LPS-stimulated upregulation of ICAM-1 expression. Downregulation of ICAM-1 may be a mechanism whereby NO. protects resting endothelium (distant organ bed) from circulating primed or activated PMNs, but may not be as effective at a primary inflammatory site.