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1.
Am J Surg ; 218(3): 584-589, 2019 09.
Article in English | MEDLINE | ID: mdl-30704668

ABSTRACT

BACKGROUND: In January 2014, Kentucky expanded Medicaid coverage in an effort to improve access to healthcare. This study evaluated the early impact of Medicaid expansion on diagnosis and treatment of benign gallbladder disease in Kentucky. METHODS: Administrative claims data were queried for patients undergoing cholecystectomy for benign gallbladder disease between 2011 and 2015. Demographic, procedure, and outcome variables from 2011 to 2013 (PRE) and 2014-2015 (POST) were compared. RESULTS: After Medicaid expansion, patients were more likely to have their operation performed as an outpatient (80.0% vs. 78.2%, p < 0.001). A significant trend was noted toward a shorter hospital stay (p < 0.001) among inpatients. For both inpatients and outpatients, a significant shift was noted toward increased hospital charges (p < 0.001). CONCLUSIONS: The expansion of Kentucky Medicaid in 2014 has been associated with an increase in outpatient cholecystectomy, shorter hospital stays for inpatients, and increased hospital charges for both inpatients and outpatients. Increased charges for all procedures may represent a mechanism for hospitals to offset the cost of providing global care for more patients.


Subject(s)
Cholecystectomy , Gallbladder Diseases/diagnosis , Gallbladder Diseases/surgery , Medicaid/organization & administration , Adolescent , Adult , Delivery of Health Care/trends , Humans , Kentucky , Middle Aged , Retrospective Studies , Time Factors , United States , Young Adult
2.
Scand J Surg ; 95(3): 146-51, 2006.
Article in English | MEDLINE | ID: mdl-17066607

ABSTRACT

The treatment of blunt splenic injury has evolved over time from splenectomy in all patients to nonoperative management in stable patients with operation reserved for failures of NOM. While rates of OPSI remain low in trauma patients, splenic salvage in stable patients should be attempted. However, clinical evidence of ongoing blood loss or instability should be addressed with prompt splenectomy. Careful patient selection is of paramount importance in nonoperative management of blunt splenic injury.


Subject(s)
Abdominal Injuries/diagnosis , Abdominal Injuries/therapy , Spleen/injuries , Wounds, Nonpenetrating , Diagnosis, Differential , Embolization, Therapeutic , Humans , Splenectomy , Trauma Severity Indices , Treatment Outcome
4.
J Trauma ; 51(5): 887-95, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11706335

ABSTRACT

BACKGROUND: The purpose of this study was to examine the contribution of age and gender to outcome after treatment of blunt splenic injury in adults. METHODS: Through the Multi-Institutional Trials Committee of the Eastern Association for the Surgery of Trauma (EAST), 1488 adult patients from 27 trauma centers who suffered blunt splenic injury in 1997 were examined retrospectively. RESULTS: Fifteen percent of patients were 55 years of age or older. A similar proportion of patients > or = 55 went directly to the operating room compared with patients < 55 (41% vs. 38%) but the mortality for patients > or = 55 was significantly greater than patients < 55 (43% vs. 23%). Patients > or = 55 failed nonoperative management (NOM) more frequently than patients < 55 (19% vs. 10%) and had increased mortality for both successful NOM (8% vs. 4%, p < 0.05) and failed NOM (29% vs. 12%, p = 0.054). There were no differences in immediate operative treatment, successful NOM, and failed NOM between men and women. However, women > or = 55 failed NOM more frequently than women < 55 (20% vs. 7%) and this was associated with increased mortality (36% vs. 5%) (both p < 0.05). CONCLUSION: Patients > or = 55 had a greater mortality for all forms of treatment of their blunt splenic injury and failed NOM more frequently than patients < 55. Women > or = 55 had significantly greater mortality and failure of NOM than women < 55.


Subject(s)
Spleen/injuries , Wounds, Nonpenetrating/mortality , Wounds, Nonpenetrating/therapy , Adult , Age Factors , Aged , Analysis of Variance , Chi-Square Distribution , Female , Humans , Male , Middle Aged , Retrospective Studies , Sex Factors , Treatment Outcome , United States
5.
J Surg Res ; 99(2): 258-64, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11469895

ABSTRACT

BACKGROUND: The inducible nitric oxide synthase (iNOS) is strongly expressed following inflammatory stimuli. Adenosine 3',5'-cyclic monophosphate (cAMP) increases iNOS expression and activity in a number of cell types but decreases cytokine-stimulated iNOS expression in hepatocytes. The mechanisms for this effect are unknown. METHODS: Rat hepatocytes were stimulated with cytokines to induce iNOS and cultured with cAMP agonists dibutyryl-cAMP (dbcAMP), 8-bromo-cAMP, and forskolin (FSK). Nitric oxide synthesis was assessed by supernatant nitrite levels and iNOS expression was measured by Northern and Western blot analyses. Nuclear factor kappaB binding was assessed by electromobility shift assay. RESULTS: Cyclic AMP dose dependently decreased NO synthesis in response to a combination of proinflammatory cytokines or interleukin-1beta (IL-1beta) alone. The adenylate cyclase inhibitor SQ 22,536 increased cytokine- or IL-1beta-stimulated NO synthesis. dbcAMP decreased iNOS mRNA expression and iNOS protein expression. Both dbcAMP and glucagon decreased iNOS promoter activity in rat hepatocytes transfected with the murine iNOS promoter and decreased DNA binding of the transcription factor NF-kappaB. CONCLUSION: These data suggest that cAMP is important in hepatocyte iNOS expression and agents that alter cAMP levels may profoundly alter the response of hepatocytes to inflammatory stimuli through effects onthe iNOS promoter region and NF-kappaB.


Subject(s)
Adenine/analogs & derivatives , Cyclic AMP/pharmacology , Hepatocytes/enzymology , NF-kappa B/metabolism , Nitric Oxide Synthase/genetics , 8-Bromo Cyclic Adenosine Monophosphate/pharmacology , Adenine/pharmacology , Adenylyl Cyclase Inhibitors , Adenylyl Cyclases/metabolism , Animals , Bucladesine/pharmacology , Cells, Cultured , Colforsin/pharmacology , Enzyme Inhibitors/pharmacology , Gene Expression Regulation, Enzymologic/drug effects , Gene Expression Regulation, Enzymologic/physiology , Glucagon/pharmacology , Hepatocytes/cytology , Interleukin-1/pharmacology , Male , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/enzymology , Nitric Oxide Synthase Type II , Promoter Regions, Genetic/physiology , Pulmonary Artery/cytology , RNA, Messenger/analysis , Rats , Rats, Sprague-Dawley , Second Messenger Systems/physiology , Sepsis/metabolism , Sepsis/physiopathology , Transfection
6.
Arch Orthop Trauma Surg ; 121(4): 219-22, 2001.
Article in English | MEDLINE | ID: mdl-11317684

ABSTRACT

Hemorrhagic shock (HS) initiates an inflammatory response that includes increased expression of inducible nitric oxide synthase (iNOS) and production of prostaglandins. Induction of iNOS during the ischemic phase of HS may involve the activation of the hypoxia-inducible factor-1 (HIF-1). Increased expression of cyclooxygenase-2 (COX-2) during HS contributes to prostaglandin production. The aim of this study was to determine whether the ischemic phase of HS results in the activation of HIF-1 and the induction of COX-2. The lungs of rats subjected to HS demonstrated a twofold increase in HIF-1 activation (P < 0.01) and a 7.4-fold increase in expression of COX-2 mRNA (P < 0.01) compared with sham controls. The upregulation of iNOS and COX-2 during ischemia are two important early response genes that promote the inflammatory response and may contribute to organ damage through the rapid and exaggerated production of nitric oxide and prostaglandins.


Subject(s)
DNA-Binding Proteins/genetics , Isoenzymes/genetics , Lung/blood supply , Nuclear Proteins/genetics , Prostaglandin-Endoperoxide Synthases/genetics , Reperfusion Injury/physiopathology , Shock, Hemorrhagic/physiopathology , Systemic Inflammatory Response Syndrome/physiopathology , Transcription Factors , Animals , Cyclooxygenase 2 , Enzyme Induction/genetics , Gene Expression/physiology , Hypoxia-Inducible Factor 1 , Hypoxia-Inducible Factor 1, alpha Subunit , Lung/pathology , Male , RNA, Messenger/genetics , Rats , Rats, Sprague-Dawley , Reperfusion Injury/pathology , Shock, Hemorrhagic/pathology , Systemic Inflammatory Response Syndrome/pathology , Up-Regulation/genetics
7.
Am Surg ; 67(2): 122-6, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11243533

ABSTRACT

Multiple organ dysfunction syndrome (MODS) is the leading cause of late deaths after traumatic injury. The relative importance of dysfunction of individual organ systems in determining outcome from MODS has not been clearly defined. Some studies have suggested that hepatic dysfunction associated with MODS increases mortality, whereas others have suggested that it contributes little to outcome in trauma patients. To clarify the role of the hepatic dysfunction after traumatic injury we retrospectively reviewed all trauma patients with an Injury Severity Score > or = 14 admitted from January 1, 1994 through June 30, 1997 for the presence of hepatic dysfunction defined as a serum bilirubin > or = 2.0 mg/dL. Of the 1962 patients who met the entry criteria 154 developed hepatic dysfunction during their hospital stay. Patients with hepatic dysfunction were older (46 +/- 2 versus 41 +/- 1 years), were more severely injured (Injury Severity Score 31.5 +/- 0.9 versus 23.3 + 0.2), and had a lower prehospital blood pressure (102 +/- 3 versus 117 +/- 1 mm Hg) compared with patients who did not develop hepatic dysfunction. Patients with hepatic dysfunction were more likely to present with shock as reflected in a lower initial emergency room blood pressure (109 +/- 3 versus 128 +/- 1 mm Hg) and base deficit (-6.9 +/- 0.6 versus -3.5 +/- 0.1 mEq/L). Patients who developed hyperbilirubinemia had longer lengths of stay in the intensive care unit (15.8 +/- 1.2 versus 3.4 +/- 0.2 days) and the hospital (27.4 +/- 1.7 versus 11.1 +/- 0.2 days) and a higher in-hospital mortality (16.2% versus 2.5%). These data demonstrate that the development of hepatic dysfunction reflects the severity of injury and is associated with a significantly worse outcome after traumatic injury.


Subject(s)
Liver Diseases/epidemiology , Multiple Organ Failure/mortality , Multiple Trauma/epidemiology , Adult , Case-Control Studies , Female , Humans , Length of Stay/statistics & numerical data , Male , Middle Aged , Retrospective Studies , Risk Factors , Trauma Severity Indices , Wounds, Nonpenetrating/epidemiology , Wounds, Penetrating/epidemiology
8.
J Trauma ; 49(2): 177-87; discussion 187-9, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10963527

ABSTRACT

BACKGROUND: Nonoperative management of blunt injury to the spleen in adults has been applied with increasing frequency. However, the criteria for nonoperative management are controversial. The purpose of this multi-institutional study was to determine which factors predict successful observation of blunt splenic injury in adults. METHODS: A total of 1,488 adults (>15 years of age) with blunt splenic injury from 27 trauma centers in 1997 were studied through the Multi-institutional Trials Committee of the Eastern Association for the Surgery of Trauma. Statistical analysis was performed with analysis of variance and extended chi2 test. Data are expressed as mean +/- SD; a value of p < 0.05 was considered significant. RESULTS: A total of 38.5 % of patients went directly to the operating room (group I); 61.5% of patients were admitted with planned nonoperative management. Of the patients admitted with planned observation, 10.8% failed and required laparotomy; 82.1% of patients with an Injury Severity Score (ISS) < 15 and 46.6% of patients with ISS > 15 were successfully observed. Frequency of immediate operation correlated with American Association for the Surgery of Trauma (AAST) grades of splenic injury: I (23.9%), II (22.4%), III (38.1%), IV (73.7%), and V (94.9%) (p < 0.05). Of patients initially managed nonoperatively, the failure rate increased significantly by AAST grade of splenic injury: I (4.8%), II (9.5%), III (19.6%), IV (33.3%), and V (75.0%) (p < 0.05). A total of 60.9% of the patients failed nonoperative management within 24 hours of admission; 8% failed 9 days or later after injury. Laparotomy was ultimately performed in 19.9% of patients with small hemoperitoneum, 49.4% of patients with moderate hemoperitoneum, and 72.6% of patients with large hemoperitoneum. CONCLUSION: In this multicenter study, 38.5% of adults with blunt splenic injury went directly to laparotomy. Ultimately, 54.8% of patients were successfully managed nonoperatively; the failure rate of planned observation was 10.8%, with 60.9% of failures occurring in the first 24 hours. Successful nonoperative management was associated with higher blood pressure and hematocrit, and less severe injury based on ISS, Glasgow Coma Scale, grade of splenic injury, and quantity of hemoperitoneum.


Subject(s)
Critical Care/statistics & numerical data , Spleen/injuries , Spleen/surgery , Splenectomy/statistics & numerical data , Wounds, Nonpenetrating/surgery , Adult , Female , Glasgow Coma Scale , Humans , Male , Retrospective Studies , Societies, Medical , Trauma Severity Indices , United States/epidemiology , Wounds, Nonpenetrating/epidemiology
9.
Am J Physiol ; 277(1): G144-51, 1999 07.
Article in English | MEDLINE | ID: mdl-10409161

ABSTRACT

We tested the ability of a nitric oxide (NO) scavenger to reduce tissue injury in a rodent model of hemorrhagic shock. Rats were hemorrhaged to a mean arterial blood pressure (MAP) of 40 mmHg and then resuscitated when either 30% of their shed blood had been returned (group 1) or after 100 min of continuous shock (group 2). Selected animals were treated with the NO scavenger NOX (30 mg. kg(-1). h(-1)) infused over 4 h. Hemorrhaged rats had a lower MAP after resuscitation compared with sham-shock control rats. NOX treatment significantly increased MAP after resuscitation from hemorrhage. Hemorrhagic shock also increased liver injury as reflected by elevated ornithine carbamoyltransferase (OCT) plasma levels, and NOX treatment significantly reduced OCT release. In addition, NOX was associated with significantly decreased hepatic neutrophil infiltration and improved 24-h survival (n = 8 of 9) compared with saline-treated shock animals (n = 3 of 9). These data suggest that excess NO mediates shock-induced tissue injury and that suppression of NO availability with NO scavengers may reduce the pathophysiological sequelae of severe hemorrhage.


Subject(s)
Free Radical Scavengers/pharmacology , Liver/drug effects , Liver/pathology , Nitric Oxide/antagonists & inhibitors , Shock, Hemorrhagic/mortality , Shock, Hemorrhagic/pathology , Thiocarbamates/pharmacology , Animals , Blood Pressure/drug effects , Cytokines/genetics , Kidney/metabolism , Kidney/pathology , Liver/metabolism , Male , Neutrophils/pathology , Ornithine Carbamoyltransferase/blood , Peroxidase/metabolism , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Shock, Hemorrhagic/physiopathology
10.
Ann Surg ; 230(1): 87-94, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10400041

ABSTRACT

BACKGROUND AND OBJECTIVE: The regional trauma system with the trauma center as its center is a model for health care networks. However, trauma center maturation has not been defined in the literature. The authors' hypothesis was that maturation of the trauma center would affect quantitatively both process and patient outcome. MATERIALS AND METHODS: A total of 15,303 trauma patients were admitted from 1987 to 1995. Annual admissions increased from 813 to 2669. Resources were generated as patient volume increased. Time to the operating room, length of stay, and complications were determined. TRISS methodology was used to calculate z scores and w values to compare actual with predicted mortality rates. RESULTS: Time to the operating room for laparotomy decreased from 62+/-73 to 35+/-47 minutes, from 32+/-32 to 20+/-17 minutes in hypotensive patients, and for craniotomy decreased from 88+/-54 to 67+/-49 minutes. The incidence of infectious, airway, neurologic, orthopedic, respiratory, gastrointestinal, and procedure-related complications declined significantly. Z scores and w values increased for penetrating and blunt injuries. Deaths for patients with ISS >15 declined significantly. Hospital length of stay decreased for all ranges of injury severity. CONCLUSIONS: As the trauma center matured, the process of delivering patient care became more efficient. The result was improved survival, fewer complications, and a shorter length of stay.


Subject(s)
Outcome and Process Assessment, Health Care/organization & administration , Trauma Centers/organization & administration , Efficiency, Organizational , Humans , Patient Admission/statistics & numerical data , Pennsylvania/epidemiology , Time and Motion Studies , Wounds and Injuries/mortality , Wounds and Injuries/therapy
11.
Shock ; 11(5): 319-24, 1999 May.
Article in English | MEDLINE | ID: mdl-10353536

ABSTRACT

Polymorphonuclear leukocytes (PMN) and inducible nitric oxide synthase (iNOS) appear to play important roles in the liver and in lung injury induced by hemorrhagic shock. Their precise roles in hemorrhagic shock-induced acute gastric mucosal lesions (AGML), however, are still poorly understood. In this study, we investigated the effect of neutropenia on hemorrhagic shock-induced AGML. We also examined the roles of iNOS in PMN infiltration into the mucosa and AGML during hemorrhagic shock by using L-N6-(1-iminoethyl)-lysine, a potent inhibitor of iNOS, and by reverse transcriptase polymerase chain reaction. Remarkable gastric mucosal damage occurs after hemorrhagic shock. PMN depletion caused by Vinblastine pretreatment significantly attenuates this AGML. Although low-dose L-N6-(1-iminoethyl)-lysine (50 microg/kg, iNOS inhibition) has no effect on AGML, high-dose L-N6-(1-iminoethyl)-lysine (250 microg/kg, iNOS + endothelial NOS inhibition) significantly exacerbates AGML without increasing PMN infiltration into the mucosa. The mRNA expression of iNOS in the stomach during hemorrhagic shock cannot be detected by reverse transcriptase polymerase chain reaction. We conclude that PMN play a pivotal role in hemorrhagic shock-induced AGML, iNOS does not regulate PMN infiltration into the mucosa, and endothelial NOS provides important protection against AGML during hemorrhagic shock.


Subject(s)
Gastric Mucosa/pathology , Neutrophils/pathology , Nitric Oxide Synthase/metabolism , Resuscitation , Shock, Hemorrhagic/metabolism , Animals , Leukocyte Count , Male , Nitric Oxide Synthase Type II , Rats , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction , Shock, Hemorrhagic/pathology
12.
Shock ; 10(5): 343-6, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9840649

ABSTRACT

The aim of this study was to assess the value of parameters of tissue oxygenation in monitoring the progression to irreversibility in a quantitative model of hemorrhagic shock. Rats were bled to a mean arterial pressure of 40 mmHg and were maintained at this level by further blood withdrawal until the compensation endpoint; this point was defined as the time at which the rat was no longer able to maintain its blood pressure at this level and shed blood was required for transfusion. The shock period was maintained until 0%, 20%, 40%, or 50% of the maximum shed blood volume (MBV) had been returned (n = 10 in each group, total n = 40). The animals were then resuscitated with remaining shed blood plus twice MBV as lactated Ringer's solution to MAP > 80 mmHg. Blood gas and serum lactate samples were measured at baseline, compensation endpoint, and at the time of resuscitation, and 24 h survival was recorded. Increasing the severity of shock progressively worsened the acidosis, with increased base deficit and lacticacidemia, and deterioration in central venous oxygen saturation (CvO2). Tissue oxygenation parameters, particularly CvO2, predicted subsequent mortality. Lactate levels only predicted irreversibility in late, severe shock. This quantitative model of hemorrhagic shock showed that tissue oxygenation parameters can be used to monitor the progression from the decompensated phase of hemorrhagic shock to irreversibility. Furthermore, this experimental study suggests that venous indices may be a valuable tool in reflecting the severity of hemorrhagic insult in a setting when arterial blood samples may not be easily available.


Subject(s)
Blood Gas Analysis , Lactic Acid/blood , Oxygen/metabolism , Shock, Hemorrhagic/metabolism , Shock, Hemorrhagic/mortality , Animals , Disease Models, Animal , Male , Oxygen/blood , Rats , Rats, Sprague-Dawley , Regression Analysis , Resuscitation
13.
Am J Surg ; 176(4): 311-4, 1998 Oct.
Article in English | MEDLINE | ID: mdl-9817245

ABSTRACT

BACKGROUND: Gastrostomies provide reliable long-term enteral access in patients with traumatic brain injuries. The impact of technique of gastrostomy on total hospital cost is not known. METHODS: A retrospective analysis of patients who sustained head trauma and required gastrostomies for long-term enteral access between 1 July 1990 and 1 July 1996 was performed. RESULTS: The patients who received percutaneous endoscopic gastrostomies (PEG) were similar to patients who received Stamm gastrostomies (OPEN) with respect to age, injury severity score, mechanism of injury, associated injuries, complication rates, and deaths. Total hospital costs ($ x 10(3)) were lower for patients who had PEGs placed in the intensive care unit (78.2 +/- 37.4) or endoscopy suite (71.9 +/- 37.7) compared with PEGs placed in the operating room (122.4 +/- 75.7) or OPEN gastrostomies (119.8 +/- 65.1). CONCLUSIONS: In head-injured patients, PEGs are a reliable method of obtaining long-term enteral access with a complication rate equivalent to Stamm gastrostomies. If performed in either the intensive care unit or the endoscopy suite, PEGs are associated with significantly reduced total hospital costs.


Subject(s)
Craniocerebral Trauma/complications , Endoscopy/economics , Gastrostomy/economics , Hospital Costs , Adult , Aged , Cost Control , Cost-Benefit Analysis , Craniocerebral Trauma/therapy , Endoscopy/adverse effects , Endoscopy/methods , Enteral Nutrition/economics , Enteral Nutrition/methods , Female , Gastrostomy/adverse effects , Gastrostomy/methods , Humans , Male , Middle Aged , Retrospective Studies , Treatment Outcome
14.
Surgery ; 122(4): 654-60, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9347839

ABSTRACT

BACKGROUND: Although highly successful in children, nonoperative management of blunt splenic injury in adults is less defined. The purpose of this study was to determine whether mechanism of injury, grade of splenic injury, associated injuries, and pattern of injury differ between adults and children (younger than 15 years of age). METHODS: Four hundred eleven patients (293 adults and 118 pediatric patients) with blunt splenic injury were admitted to an affiliated adult/pediatric trauma program from 1989 to 1994. Computed tomography (CT) scans were interpreted in a blinded fashion. Mechanism of injury was significantly different for adults versus children (p < 0.05): motor vehicle crash (66.9% versus 23.7%), motorcycle (8.8% versus 0.8%), sports (2.4% versus 16.9%), falls (8.8% versus 25.4%), pedestrian/automobile (4.4% versus 11.0%), bicycle (1.4% versus 9.3%), and other (7.3% versus 12.7%). RESULTS: Higher injury severity scores, lower Glasgow Coma Scales, and higher mortality indicated that the adults were more severely injured than the children. Fifty-nine percent of the adults and 7% of the children required immediate laparotomy for splenic injury. Both CT grade and quantity of blood on CT predicted the need for exploration in adults but not in children. An injury severity score above 15 and high-energy mechanisms correlated with the need for operative intervention. CONCLUSIONS: Rather than children simply being physically different, they are injured differently than adults, hence the high rate of nonoperative management.


Subject(s)
Spleen/injuries , Wounds and Injuries/epidemiology , Wounds, Nonpenetrating/classification , Wounds, Nonpenetrating/surgery , Accidents, Traffic , Adult , Age Factors , Child , Fractures, Bone/classification , Fractures, Bone/epidemiology , Glasgow Coma Scale , Humans , Injury Severity Score , Retrospective Studies , Tomography, X-Ray Computed , Wounds and Injuries/classification , Wounds, Nonpenetrating/diagnostic imaging
15.
J Trauma ; 43(4): 673-9, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9356066

ABSTRACT

Prehospital guidelines for the treatment of penetrating trauma recommend rapid volume resuscitation to normal blood pressure. There is evidence, however, that fluid resuscitation to normal blood pressure in the setting of uncontrolled hemorrhagic shock (UHS) causes increased bleeding, hemodilution, and mortality. To test this hypothesis, we evaluated the effects of blood pressure and hemodilution on survival in a rat model of UHS. UHS was produced in rats by preliminary bleed of 3 mL/100 g followed by a 75% tail amputation. Experimental design consisted of three phases: a prehospital phase, with uncontrolled bleeding and resuscitation to either 40 or 80 mm Hg with lactated Ringer's solution (LR) or lactated Ringer's solution and whole blood (WB); followed by a hospital phase, with control of the bleeding and continued resuscitation to mean arterial pressure (MAP) > 80 mm Hg and hematocrit near 30%; followed by a 3-day observation phase. There were four treatment groups, n = 8 in each group: group I, MAP = 80 mm Hg with LR only; group II, MAP = 80 mm Hg with WB and LR; group III, MAP = 40 mm Hg with LR only; and group IV, MAP = 40 mm Hg with WB and LR. All group I rats died within 2.5 hours. There were no significant differences in survival among groups II, III, and IV. Base deficit, arterial pH, and lactate levels were significantly worse in the rats resuscitated to a MAP of 80 mm Hg with LR (group I). The effects of blood pressure alone, hemodilution alone, and their interaction were significantly related to base deficit and arterial pH. Hemodilution, but not blood pressure as an end point in resuscitation, was significantly related to lactate levels. The high mortality in this model of uncontrolled hemorrhage was attributable to the effects of blood pressure, hemodilution, and the interaction between the two variables, rather than simply continued blood loss from increased hydrostatic pressure.


Subject(s)
Hemodilution , Shock, Hemorrhagic/therapy , Animals , Blood Pressure , Disease Models, Animal , Hematocrit , Hypotension/physiopathology , Rats , Rats, Sprague-Dawley , Shock, Hemorrhagic/mortality , Shock, Hemorrhagic/physiopathology
17.
J Leukoc Biol ; 61(6): 712-20, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9201262

ABSTRACT

Macrophage nitric oxide (NO) synthesis is an integral component of the host defense system. We have previously found that NO and prostaglandins interact in a variety of ways. NO modulates Kupffer cell prostaglandin E2 (PGE2) production and we have recently described the inhibitory effects of PGE2 on NO synthesis in both Kupffer cells and hepatocytes. Activated macrophages produce a number of prostaglandins but studies regarding the capacity of prostaglandins to regulate macrophage NO synthesis have yielded conflicting results. We found that exogenous PGE2 decreased lipopolysaccharide (LPS)-induced NO synthesis in murine resident peritoneal macrophages and in the RAW 264.7 murine macrophage cell line. PGE2 also suppressed NO synthesis in response to interferon-gamma (IFN-gamma) alone and a combination of LPS + IFN-gamma. Inhibition of endogenous PGE2 synthesis with indomethacin or ibuprofen had no effect on NO synthesis. PGE2 added with the activating stimulus was most effective. PGE2 lost the capacity to block NO synthesis if added more than 180 min after LPS. PGE2 decreased inducible NO synthesis (iNOS) mRNA and immunoreactive iNOS protein, consistent with the hypothesis that exogenous PGE2 inhibits macrophage iNOS expression but that the inhibition depends on the time and concentration of prostaglandin exposure.


Subject(s)
Dinoprostone/pharmacology , Interferon-gamma/pharmacology , Lipopolysaccharides/pharmacology , Macrophages/metabolism , Nitric Oxide/antagonists & inhibitors , Nitric Oxide/biosynthesis , Animals , Cell Line , Macrophages/drug effects , Macrophages/enzymology , Mice , Mice, Inbred BALB C , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide Synthase/genetics , RNA, Messenger/antagonists & inhibitors , Time Factors
18.
Ann Surg ; 225(1): 76-87, 1997 Jan.
Article in English | MEDLINE | ID: mdl-8998123

ABSTRACT

OBJECTIVE: The authors determine the relationship between glutathione and nitric oxide (NO) synthesis in cultured hepatocytes. SUMMARY BACKGROUND DATA: Glutathione is a cofactor for a number of enzymes, and its presence is essential for maximal enzyme activity by the inducible macrophage nitric oxide synthase (iNOS), which produces the reactive nitric oxide radical. Hepatocytes contain substantial quantities of glutathione, and this important tripeptide is decreased in hepatocytes stressed by ischemia/reperfusion or endotoxemia. Endotoxemia also induces the synthesis of inflammatory cytokines that result in the production of nitric oxide from hepatocytes by iNOS, suggesting that hepatocytes may be attempting to synthesize nitric oxide at times when intracellular glutathione is reduced. METHODS: Hepatocytes were cultured with buthionine sulfoximine and 1,3-bis(chloroethyl)-1-nitrosourea (BCNU) to inhibit glutathione. After exposure to cytokines, NO synthesis was assessed by supernatant nitrite levels, cytosolic iNOS enzyme activity, and iNOS mRNA levels. RESULTS: Inhibition of glutathione synthesis with buthionine sulfoximine or inhibition of glutathione reductase activity with BCNU inhibited nitrite synthesis. Both buthionine sulfoximine and BCNU inhibited the induction of iNOS mRNA, as detected by Northern blot analysis. Exogenous glutathione increased cytokine-stimulated iNOS induction, overcame the inhibitory effects of BCNU, and increased nitrite production by intact hepatocytes, induced hepatocyte cytosol, and partially purified hepatocyte iNOS. CONCLUSIONS: In cultured hepatocytes, adequate glutathione levels are required for optimal nitric oxide synthesis. This finding is predominantly due to an effect on iNOS mRNA levels, although glutathione also participates in the regulation of iNOS enzyme activity.


Subject(s)
Glutathione/physiology , Liver/cytology , Liver/enzymology , Nitric Oxide Synthase/physiology , Nitric Oxide/biosynthesis , Animals , Buthionine Sulfoximine/pharmacology , Carmustine/pharmacology , Cells, Cultured , Enzyme Inhibitors/pharmacology , Glutathione/antagonists & inhibitors , Male , Rats , Rats, Sprague-Dawley
19.
Shock ; 8(6): 415-21, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9421854

ABSTRACT

Hemorrhagic shock results in hepatocellular dysfunction and hepatic injury that may contribute to the development of liver failure and multiple organ dysfunction in trauma patients. The specific mediators involved in this process remain incompletely defined. We have previously demonstrated that inhibition of nitric oxide (NO) synthesis in a rat model of moderately severe hemorrhagic shock increases hepatic injury, suggesting that NO synthesis is beneficial after hemorrhage. To further define the role of NO in hepatic function during hemorrhagic shock, rats were subjected to a severe hemorrhagic shock insult in which they were bled to a mean arterial pressure of 40 mmHg until 40% of their shed blood had been returned and then were resuscitated. Rats were treated with the NO synthase inhibitor L-nitroarginine methyl ester (L-NAME) or the NO donor S-nitroso-N-acetylpenicillamine beginning either during the hypotensive period or after resuscitation. When instituted during the hypotensive period, low dose L-NAME infusion significantly increased hepatic injury. When L-NAME was infused after resuscitation, no increase in hepatic injury was detected even when the L-NAME dose was increased by a factor of four. The increased hepatic injury produced by L-NAME was associated with increased myeloperoxidase content in the lung, suggesting that L-NAME led to a greater accumulation of neutrophils during shock. Administration of the NO donor S-nitroso-N-acetylpenicillamine reduced hepatocellular enzyme release. Our results suggest that ongoing NO synthesis during the hypotensive phase of hemorrhagic shock is essential in preventing shock-induced hepatic injury and this may be due, in part, to the interaction between NO and circulating neutrophils.


Subject(s)
Hemorrhage/blood , Liver Diseases/etiology , Neutrophils/drug effects , Neutrophils/metabolism , Nitric Oxide/antagonists & inhibitors , Nitric Oxide/biosynthesis , Resuscitation , Shock, Hemorrhagic/drug therapy , Alanine Transaminase/blood , Alanine Transaminase/drug effects , Animals , Antirheumatic Agents/therapeutic use , Aspartate Aminotransferases/blood , Aspartate Aminotransferases/drug effects , Endothelium/chemistry , Endothelium/cytology , Enzyme Inhibitors/therapeutic use , Intestines/enzymology , Lung/enzymology , Male , NG-Nitroarginine Methyl Ester/therapeutic use , Neutrophils/chemistry , Ornithine Carbamoyltransferase/blood , Ornithine Carbamoyltransferase/drug effects , Penicillamine/therapeutic use , Peroxidase/drug effects , Peroxidase/metabolism , Rats , Rats, Sprague-Dawley , Shock, Hemorrhagic/complications , Time Factors
20.
Nitric Oxide ; 1(5): 404-16, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9441911

ABSTRACT

The roles of nitric oxide derived from either the constitutive endothelial NO synthase (eNOS or NOS3) or the inducible NOS (iNOS or NOS2) in hepatic injury during endotoxemia remain controversial. To investigate this further, rats received a bolus of lipopolysaccharide (LPS) following implantation of osmotic pumps containing one of two nonselective NOS inhibitors (NMA or NAME), one of two inducible NOS inhibitors (NIL or AG), or saline. The inhibitors were infused continuously into the liver via the portal vein. Treatment of LPS-injected rats with NMA and NAME resulted in 106 and 227% increases, respectively, in circulating hepatic enzyme levels compared to LPS-treated control rats. In contrast, infusion of the iNOS-selective inhibitors had no effect on the LPS-induced hepatic necrosis. In rats receiving NAME, LPS induced greater neutrophil infiltration and ICAM-1 expression than in the LPS + saline group, whereas NIL infusion did not. The increased hepatic necrosis and PMN infiltration in the LPS + NAME group was partially prevented by a simultaneous infusion of a liver-selective NO donor. Inhibition of PMN accumulation using an anti-ICAM-1 antibody or by PMN depletion using vinblastine pretreatment, however, did not reverse the increased necrosis with NAME infusion during endotoxemia. In contrast to the assessment for necrosis, increased apoptosis was observed in the livers of LPS-treated rats receiving infusions of either NAME or NIL, but not with LPS alone. These data indicate that NO produced by eNOS may be adequate to prevent necrosis by a mechanism independent of PMN, while induced NO appears to prevent apoptosis.


Subject(s)
Endotoxemia/physiopathology , Intercellular Adhesion Molecule-1/biosynthesis , Liver/pathology , Liver/physiopathology , NG-Nitroarginine Methyl Ester/pharmacology , Neutrophils/physiology , Nitric Oxide Synthase/antagonists & inhibitors , omega-N-Methylarginine/pharmacology , Animals , Apoptosis/drug effects , DNA Fragmentation , Endotoxemia/pathology , Liver/drug effects , Male , Necrosis , Neutrophils/drug effects , Nitrates/blood , Nitric Oxide Synthase Type II , Nitric Oxide Synthase Type III , Nitrites/blood , Rats , Rats, Sprague-Dawley
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