Biomedical subjects

C R Blocher

Publications and source records attributed to C R Blocher.

At least 19 recordsLinked to original sources

PubMed1995

Beneficial effects of a bradykinin antagonist in a model of gram-negative sepsis.

UNLABELLED: Activation of the kallikrein-kinin system in sepsis has long been recognized, but its role, beneficial or pathologic, has not been determined. Recently, however, specific bradykinin (BK) antagonists have become available and we sought to determine the effects of a BK antagonist, NPC17731, in a model of sepsis-induced acute lung injury (ALI). METHODS: Anesthetized swine were studied for 5 hours, receiving a 1-hour infusion of saline (Controls) or live Pseudomonas aeruginosa (Septic untreated). Treatment groups received a 5 mg/kg bolus of NPC17731 followed by a 1 mg/kg bolus hourly commencing either just before sepsis (Pretreatment) or 30 minutes following the onset of sepsis (Posttreatment). RESULTS: Septic untreated animals showed a rapid, progressive decline in arterial PaO2 compared to controls, and this was significantly improved in both treatment groups. Bronchoalveolar lavage at 5 hours in both treatment groups also showed significant decreases in neutrophil (PMN) counts and protein content compared to untreated septic animals, indicating decreased PMN migration and alveolar-capillary membrane damage. Both treatment groups also showed reduced PMN sequestration in the lung compared to untreated animals, although PMNs did exhibit significant upregulation of PMN CD18 receptor expression and superoxide generation. CONCLUSIONS: These data imply a significant role for BK in the pathogenesis of sepsis-induced ALI. Use of a competitive BK antagonist significantly attenuated the development of ALI without inhibiting PMN activation. BK antagonists may be a useful adjunct in the armamentarium against sepsis-induced ALI.

Animals↗

PubMed1995

Cardiopulmonary effects of raised intra-abdominal pressure before and after intravascular volume expansion.

The cardiopulmonary effects of acutely elevated intra-abdominal pressure (IAP) were studied in a porcine model to help define more clearly IAP effects in patients with trauma. IAP was increased in six anesthetized swine by intra-abdominal instillation of isotonic ethylene glycol up to an IAP of 25 mm Hg above baseline. Systemic and pulmonary hemodynamic parameters were measured, as well as the effects on bladder pressure, pleural pressure, and pulmonary function. At IAP of 25 mm Hg above baseline, intravascular volume expansion with saline was administered to return the cardiac index (CI) to baseline. Raising IAP correlated with measured bladder pressures (r = 0.9, p = 0.001). At IAP of 25 mm Hg, CI was significantly decreased (p < 0.05, analysis of variance (ANOVA); 3.6 +/- 0.3 vs. 2.2 +/- 0.3 L/min/m2); whereas wedge, pulmonary arterial, and pleural pressures were all elevated (p < 0.05, ANOVA). However, transarterial wedge pressure (wedge--pleural pressure) declined nonsignificantly with increasing IAP. Raised IAP caused impaired pulmonary function with a decreased (p < 0.05, ANOVA) PaO2 and increased (p < 0.05, ANOVA) PaCO2. Despite the elevated wedge pressure, fluid resuscitation returned CI to baseline. These data clarify the hemodynamic changes associated with raised IAP and indicate that care must be taken in interpreting hemodynamic measurements to determine intravascular fluid status in patients with elevated IAP.

Abdomen↗

PubMed1995

A dual-binding antibody to E- and L-selectin attenuates sepsis-induced lung injury.

Many studies indicate a pivotal role for neutrophil adhesion in sepsis-associated lung injury. Neutrophil adhesion to endothelium depends on activation and expression of selectin and integrin adhesion receptors. We studied the effects of pretreatment with a dual-binding porcine anti-E- and anti-L-selectin monoclonal antibody (EL-246) on a porcine model of sepsis-induced lung injury. Four groups were studied for 5 h. Group 1 (control animals) received intravenous saline only. Group 2 (septic) received a 1-h infusion of Pseudomonas aeruginosa. Group 3 (EL-246 pretreatment) received EL-246 (1 mg/kg) prior to Pseudomonas infusion. Group 4 (EL-246 controls) received EL-246 infusion only. Group 2 animals showed rapid, significant decline in arterial pH and oxygen tension whereas, in Group 3, physiologic deterioration was significantly attenuated. Bronchoalveolar lavage at 5 h showed a significant increase in neutrophil count and protein content in Group 2. Group 3, however, showed no significant differences in these parameters compared with control animals. Despite severe neutropenia, lung myeloperoxidase content at 5 h was significantly reduced in Group 3 compared with Group 2. There was no significant difference in pulmonary and systemic hemodynamics between Groups 2 and 3. Group 4 animals exhibited a transient neutropenia, but otherwise no other differences in measured parameters were found compared with Group 1 control animals. In conclusion, EL-246 significantly reduced neutrophil accumulation in lung and attenuated sepsis-induced lung injury, but failed to attenuate deranged pulmonary and systemic hemodynamics.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Delayed tumor necrosis factor alpha blockade attenuates pulmonary dysfunction and metabolic acidosis associated with experimental gram-negative sepsis.

OBJECTIVE: To ascertain the effect of delayed tumor necrosis factor alpha (TNF-alpha) on the evolution of systemic and pulmonary injury after the onset of sepsis. DESIGN: Prospective controlled trial. INTERVENTION: Anesthetized swine were made septic with a 1-hour infusion of live Pseudomonas aeruginosa, following which a treatment group received an infusion of anti-TNF-alpha monoclonal antibody (5 mg/kg). Control animals received 0.9% saline. RESULTS: Delayed anti-TNF-alpha treatment had no effect on septic pulmonary hypertension or decline in cardiac output. Late recovery in systemic arterial hypotension was associated with a reversal of arterial acidosis (P < .05 by t test and analysis of variance with Tukey's Studentized Range Test) compared with unprotected septic animals. Septic animals had a significant increase in mean (+/- SEM) plasma lactate levels at 5 hours compared with baseline values (3.8 +/- 0.7 vs 2 +/- 0.4, P < .05), but remained unchanged from baseline following anti-TNF-alpha treatment (1.5 +/- 0.1 vs 1.6 +/- 0.2, not significant). Characteristic septic neutropenia was dramatically reversed by anti-TNF-alpha treatment and was associated with downregulation (P < .05 by t test and analysis of variance) of polymorphonuclear neutrophil (PMN) leukocyte CD18 adhesion receptors and reduction (P < .05 by t test and analysis of variance) in lung PMN sequestration measured by myeloperoxidase activity. The mean (+/- SEM) decrease in bronchoalveolar lavage protein indicated an attenuated permeability injury in anti-TNF-alpha animals (septic animals at 5 hours compared with baseline value, 1044 +/- 270 vs 149 +/- 28 micrograms/mL; control animals at 5 hours compared with baseline value, 217 +/- 83 vs 129 +/- 19 micrograms/mL; P < .05 by t test and analysis of variance). CONCLUSIONS: These data show that delayed anti-TNF-alpha treatment reversed metabolic acidosis associated with sepsis. Furthermore, anti-TNF-alpha treatment reversed septic neutropenia, reduced PMN sequestration, and was associated with attenuated lung injury in a model of fulminant sepsis. This supports evidence of PMN-mediated tissue injury in sepsis and suggests mechanisms for potential therapeutic benefit of anti-TNF-alpha treatment in clinical practice.

Acidosis, Lactic↗

PubMed1994

Beneficial cardiopulmonary effects of pentoxifylline in experimental sepsis are lost once septic shock is established.

OBJECTIVE: To determine the effects of pretreatment and posttreatment with pentoxifylline in a porcine model of gram-negative sepsis. DESIGN: Nonrandomized controlled trial. STUDY SUBJECTS: Young Yorkshire swine. INTERVENTIONS: Six groups of ventilated swine were studied for 5 hours. Group 1 swine (control, n = 8) received saline solution only. Group 2 swine (sepsis, n = 8) received a 1-hour infusion of Pseudomonas aeruginosa. Groups 3, 4, and 5 swine received the P aeruginosa infusion and a 20 mg/kg bolus followed by a 6 mg/kg per hour infusion of pentoxifylline. Group 3 swine (n = 6) received pentoxifylline prior to the onset of sepsis; group 4 swine (n = 6) received pentoxifylline at 1 hour and group 5 swine (n = 4) at 2 hours after the onset of the P aeruginosa infusion. Group 6 swine (control pentoxifylline, n = 3) received pentoxifylline only. OUTCOME MEASURES: Hemodynamic variables, neutrophil counts and CD18 expression, tumor necrosis factor activity, and arterial blood gases were measured hourly. Bronchoalveolar lavage was performed at 0 and 5 hours to measure neutrophil and protein content. RESULTS: All variables remained unchanged in the control and control pentoxifylline groups. Both pretreatment and posttreatment with pentoxifylline significantly attenuated lung injury and improved arterial PaO2. The cardiac index was significantly improved by administration of pentoxifylline in groups 3 and 4. Administration of pentoxifylline to group 5 animals in established septic shock caused uncontrolled, fatal systemic hypotension in two of the four animals. Plasma tumor necrosis factor activity, blood polymorphonuclear leukocyte counts, and CD18 expression were unaffected by the administration of pentoxifylline. CONCLUSIONS: Pentoxifylline protects against pulmonary and systemic hemodynamic derangements in fulminant sepsis and protects against pulmonary dysfunction. Pentoxifylline has a "therapeutic window" when given in established sepsis; if administration is delayed until overt septic shock occurs, it may then have deleterious effects.

Animals↗

PubMed1994

Differential activation of alveolar, pulmonary arterial, and systemic arterial neutrophils demonstrates the existence of distinct neutrophil subpopulations in experimental sepsis.

Neutrophils (PMNs) are considered key cellular mediators of sepsis induced acute lung injury. PMN activation is manifest by increased beta 2 integrin expression and enhanced superoxide radical (O2-) generation. What is unclear is at which anatomical sites PMNs are activated and at which sites they release O2- and mediate lung injury. In this study we compared alveolar (ALV), systemic arterial (SA), and pulmonary arterial (PA) PMNs CD18 receptor expression, measured by fluorescent immunophenotyping and, O2- generation, measured by reduction of ferricytochrome C, in septic swine. Swine were anesthetized and ventilated, and given a 1-h infusion of live Pseudomonas aeruginosa. PA, SA, and ALV PMNs were isolated at 0 and 5 h. ALV PMNs O2- was reduced compared to SA blood PMNs O2- at 5 h, (AIV 5 h 23.6 +/- 3 vs. SA 0 h 34.3 +/- 5, p < .05). SA PMNs O2- generation was also significantly reduced compared to PA PMNs at 5 h (PA 5 h 21 +/- 2.5 vs. SA 5 h 16.9 +/- 2.6, p < .05). Alv PMNs expressed significantly greater CD18 receptor levels than SA blood PMNs at 5 h (AIV PMNs 5 h, 76 +/- 6 vs. SA PMNs 5 h 51 +/- 3, p < .05), however, PA PMNs CD18 receptor levels were not significantly different from SA PMNs levels at 5 h. These data corroborate a dissociation between two PMN functions in sepsis. O2- generation was reduced across the lung and following migration. However, alveolar PMNs had significantly upregulated CD18 expression compared to PMNs in PA and SA.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Combined ibuprofen and monoclonal antibody to tumor necrosis factor-alpha attenuate hemodynamic dysfunction and sepsis-induced acute lung injury.

A number of key mediators are implicated in the pathophysiology of sepsis. In previous studies of a septic porcine model, ibuprofen pretreatment prevented the early but not the late rise in pulmonary vascular resistance index (PVRI) and the early but not the late fall in arterial PO2 (PaO2), whereas monoclonal antibody to tumor necrosis factor alpha (anti-TNF alpha) prevented the late but not the early rise in PVRI and the late but not the early fall in PaO2. This study examined the impact of pretreatment with combined ibuprofen and anti-TNF-alpha on the course of sepsis and acute lung injury (ALI) in pigs. Three groups were studied for 5 hours. Groups I (n = 9) and II (n = 5) received a 1-hour infusion of Pseudomonas aeruginosa. Group II received ibuprofen (12.5 mg/kg) and anti-TNF-alpha (5 mg/kg) before P. aeruginosa, and a further bolus of ibuprofen at 120 minutes. Group III (n = 11) received sterile saline. Group I demonstrated a significant (p < 0.05) rise in plasma TNF-alpha that was abolished in group II. The SVRI in group II did not change significantly from baseline through the study and the SVRI rose sharply in group I following onset of the infusion of P. aeruginosa, as did PVRI. There was no significant change in PVRI from baseline in group II, except for the final 60 minutes; PVRI in group II was significantly less than in group I throughout the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Tumor necrosis factor-alpha blockade prevents neutrophil CD18 receptor upregulation and attenuates acute lung injury in porcine sepsis without inhibition of neutrophil oxygen radical generation.

Tumor necrosis factor (TNF alpha), both by direct action and by trafficking cells of the immune system, is implicated in cardiopulmonary derangements and PMN-mediated microvascular injury associated with gram-negative sepsis. We examined the effects of pretreatment with a monoclonal antibody to TNF alpha on PMN function, hemodynamic derangements, and alveolar capillary membrane damage in a septic porcine model. Anti-TNF alpha profoundly improved hemodynamic consequences in this model. Reduction in PMN CD11/18 receptor expression, lung myeloperoxidase activity, and attenuation of peripheral neutropenia (all P < 0.05) indicate that pretreatment significantly reduced lung sequestration of PMNs seen in septic controls. In contrast, PMN oxygen radical (O2-) generation was not significantly different from unprotected septic animals. Despite the presence of circulating PMNs primed for O2- burst, alveolar capillary membrane damage, assessed by bronchoalveolar lavage protein content and arterial PO2 was markedly attenuated in the treatment group (P < 0.05). We conclude that anti-TNF alpha suppresses systemic hemodynamic actions of TNF alpha. Further, it prevents upregulation of PMN adhesion receptors inhibiting PMN/endothelial cell interaction. This prevents formation of a "microenvironment," protected from circulating oxidant scavengers, into which sepsis-activated PMNs release their toxic products. Pretreatment with anti-TNF alpha monoclonal antibody thus affords global protection in porcine Gram-negative sepsis.

Animals↗

PubMed1991

In situ pulmonary vascular perfusion for improved recovery of pulmonary intravascular macrophages.

The microcirculation contains mononuclear phagocytes, with features characteristic of macrophages, adhered to luminal capillary surfaces by intercellular adhesion plaques. These pulmonary intravascular macrophages may play an important role in regulating lung vascular tone and capillary permeability, and may modulate capillary endothelial cell growth and replication by the secretion of soluble mediators (i.e., arachidonate metabolites, cytokines). This study describes a technique which utilizes in situ lung perfusion to remove intravascular macrophages in large numbers from the microcirculation of porcine lung (n = 26). This technique yielded 3.8 +/- 0.5 x 10(8) (mean +/- SEM) mononuclear cells which were highly phagocytic toward particulate carbon (phagocytic index, 80 +/- 6%). Harvested mononuclear phagocytes reestablished intercellular adhesion plaques when placed on small vessel porcine pulmonary artery endothelial cell monolayers and exhibited histochemical characteristics typical of monocyte/macrophage lineage cells. Mononuclear cells obtained from lung microcirculation displayed size heterogeneity varying from 10.4 to 16.5 microns in diameter. Both large and small cell populations phagocytosed particulate carbon. Morphometric studies performed on collagenase-treated lung demonstrated that in situ perfusion removed significant numbers of intravascular macrophages in lung capillaries. The technique described permits the rapid removal of anchored mononuclear phagocytes from lung capillaries with minimal postmortem delay.

Animals↗

PubMed1991

Ibuprofen prevents deterioration in static transpulmonary compliance and transalveolar protein flux in septic porcine acute lung injury.

UNLABELLED: The effects of intravenous ibuprofen on measurements of pulmonary function and alveolar capillary membrane permeability to protein in sepsis-induced porcine acute lung injury (ALI) were studied. Young swine (15-25 kg) were anesthetized, cannulated, and ventilated (5 cm H2O PEEP, 0.5 FIO2, and 15 cc/kg tidal volume). Three groups were studied: septic animals (Ps, n = 10) received Pseudomonas aeruginosa for 1 hr IV, controls (C, n = 9) received 0.9% NaCl, and ibuprofen-treated septic animals (Ps + Ibu, n = 7) received ibuprofen 12.5 mg/kg at 0 and 120 min post Ps. Systemic (SAP) and pulmonary (PAP) arterial pressures, PaO2, cardiac index (CI), static lung compliance (CL), EVLW (thermal cardiogreen), and peripheral white blood cell counts (WBC) were measured. Bronchoalveolar lavage (BAL) was performed for protein and % neutrophil (%PMN) content. RESULTS: Ps produced significant (p less than 0.05) decreases in CL, PaO2, SAP, CI, and peripheral WBC and increases in PAP, EVLW, BAL protein, and %PMN's vs. controls. Ibu prevented the early increase in PAP and attenuated the late increase in PAP and EVLW. Ibu also maintained PaO2, CL, BAL protein, and %PMN's in BAL at control levels, but exhibited no significant effect on peripheral leukopenia. These data strongly suggest that ibuprofen administered before and at 120 min after onset of Pseudomonas infusion improves lung compliance and affects neutrophil function sufficiently to significantly ameliorate many of the physiologic derangements in acute sepsis.

Acute Disease↗

PubMed1990

Increased survival time after delayed histamine and prostaglandin blockade in a porcine model of severe sepsis-induced lung injury.

A combination of cimetidine, diphenhydramine, and ibuprofen has been shown to be an effective treatment in a porcine model of septic acute lung injury. The present study was designed to evaluate this therapy in a delayed treatment survival model. Three groups of animals were studied: a control group (C, n = 6) received a sham infusion of 0.9% saline; a septic group (Ps, n = 5) received a continuous infusion of live Pseudomonas aeruginosa organisms; and a treatment group (CID, n = 6) received P. aeruginosa plus cimetidine 150 mg, ibuprofen 12.5 mg/kg, and diphenhydramine 10 mg/kg given at 90 min after P. aeruginosa infusion, and hourly thereafter. Group Ps developed fulminant acute lung injury and hypodynamic septic shock. CID therapy ameliorated temporarily the progressive course of hypoxemia and increased extravascular lung water (EVLW), delayed the onset of cardiovascular deterioration, and improved significantly survival time. It was concluded that CID therapy given at 90 min after the onset of lethal continuous P. aeruginosa infusion improved significantly animal survival time by improving temporarily hypoxemia and increase in EVLW and delaying cardiovascular collapse.

Animals↗

PubMed1990

Pulmonary compliance: early assessment of evolving lung injury after onset of sepsis.

We compared the sensitivity of dynamic (Cdyn) and static lung compliance (CL) with indicators of permeability injury in a model of septic porcine adult respiratory distress syndrome. Two groups of anesthetized ventilated swine (15-25 kg) were studied. Septic animals (Ps, n = 13) received Pseudomonas aeruginosa intravenously for 1 h, which resulted in severe adult respiratory distress syndrome. Controls (C, n = 13) received 0.9% NaCl. Cdyn, CL, bronchoalveolar lavage for protein estimation, and thermal cardiogreen extravascular lung water (EVLW) measurements were performed in seven C and eight Ps animals. Six C and five Ps animals underwent gamma camera measurement of lung-to-heart ratio (slope index) of 99Tc-labeled human serum albumin. Both Cdyn and CL decreased significantly (P less than 0.01) at 30 min and thereafter in Ps vs. C. EVLW, slope index, and bronchoalveolar protein content increased significantly (P less than 0.05) in Ps vs. C at 120, 150, and 300 min, respectively. Cdyn and CL decreased well before onset of permeability injury. These early changes may be due to release of vasoactive mediators and sequestration of neutrophils in the pulmonary capillaries and later to increases in EVLW. Measurement of Cdyn and CL represents an early means of assessing evolving lung injury in this acute septic porcine model.

Animals↗

PubMed1990

Ranitidine compared to cimetidine in multiagent pharmacological treatment of porcine Pseudomonas ARDS.

The effects of two pharmacologically distinct histamine H2 receptor antagonists were studied in combination with ibuprofen (I) and diphenhydramine (D) in a porcine model of septic ARDS. Cimetidine (C) is reported as having direct oxygen radical scavenging abilities and is an inhibitor of cytochrome P-450, whereas ranitidine (R) acts solely by H2 receptor blockade. Four groups were studied: Group Ps (n = 8) received a continuous infusion of live Pseudomonas aeruginosa 5 x 10(8) CFU/ml at 0.3 ml/20kg/min, Group C (n = 6) received a control saline infusion, and the treatment groups received I (12.5 mg/kg) and D (10 mg/kg) in combination with either C (150 mg, CID, n = 6) or R (25 mg, RID, n = 5) given at 20 and 120 minutes after the onset of Ps. Pulmonary (PAP) and systemic (SAP) arterial pressures, cardiac index (CI), PaO2, thermal cardiogreen extravascular lung water (EVLW) and scintigraphically determined pulmonary albumin flux (slope index, SI) were measured. Ps infusion produced significant (p less than 0.05) cardiovascular collapse, hypoxemia and increased EVLW and SI. Both CID and RID temporarily reversed pulmonary arterial hypertension and maintained PaO2, EVLW, SAP and CI at control levels throughout the study, and significantly improved SI at 180 min. These results suggest that cimetidine and ranitidine act in this combination therapy primarily as H2 receptor antagonists.

Animals↗

PubMed1987

Treatment of porcine Pseudomonas ARDS with combination drug therapy.

A combination drug therapy (Poly-5: ibuprofen 12.5 mg/kg, methylprednisolone 30 mg/kg, cimetidine 150 mg, diphenhydramine 10 mg/kg, and ketanserin 0.2 mg/kg) given at 20 and 120 minutes after starting continuous intravenous Pseudomonas (Ps, 5 X 10(8) CFU/20 kg/min) was studied in three groups of swine: saline control (C, n = 9), Ps alone (Ps, n = 8), and Ps plus Poly-5 (n = 5). PaO2, systemic (SAP) and pulmonary arterial (PAP) pressures, cardiac index (CI), thermal-cardiogreen extravascular lung water (EVLW), pulmonary albumin flux (slope index, SI), and arterial blood serotonin levels (5-HT) were measured. Ps produced significant (p less than 0.05) increases in PAP, EVLW, and SI with decreases in PaO2, CI, and SAP. 5-HT fell significantly compared to baseline. Poly-5 prevented (p less than 0.05) the rise in EVLW and SI and the fall in PaO2 and CI compared to Ps. PAP and SI were maintained at C until 90 and 150 minutes, respectively. SAP fell significantly from C at 30, 60, and 180 minutes. 5-HT was significantly lower than Ps throughout, and significantly lower than baseline at 180 minutes. Combined blockade of arachidonic acid metabolites, histamine, and serotonin receptors prevented hypoxemia, increased pulmonary capillary permeability, and cardiovascular deterioration in this porcine septic ARDS model.

Animals↗

PubMed1987

Successful treatment of adult respiratory distress syndrome by histamine and prostaglandin blockade in a porcine Pseudomonas model.

Porcine Pseudomonas adult respiratory distress syndrome (ARDS) has been shown to respond to combination therapy of 150 mg of cimetidine, 12.5 mg/kg of ibuprofen, 10 mg/kg of diphenhydramine, 0.2 mg/kg of ketanserin, and 30 mg/kg of methylprednisolone (CIDKM or Poly-5) given at 20 and 120 minutes after the onset of a continuous infusion of liver Pseudomonas aeruginosa, 5 X 10(8) colony-forming units (CFU) ml at 0.3 ml/20 kg/min. The present study was designed to determine the minimal, effective therapy by selective deletion of individual agents from CIDKM. Eight groups were studied: saline control (S, n = 9), Pseudomonas control (P, n = 8), and the following Pseudomonas plus treatment groups (each n = 5): CIDKM (cimetidine, ibuprofen, diphenhydramine, and ketanserin), CID (cimetidine, ibuprofen, and diphenhydramine), IC (ibuprofen and cimetidine), ID (ibuprofen and diphenhydramine), and CD (cimetidine and diphenhydramine). Pseudomonas alone produced severe ARDS with significant (p less than .05) decreases in PAO2 cardiac index, and systemic arterial pressure and significant increases in pulmonary artery pressure, extravascular lung water (EVLW) and scintigraphically determined pulmonary albumin flux measured as slope index (SI). Full therapy, CIDKM or Poly-5, showed significant improvement in all parameters. Deletion of methylprednisolone did not significantly effect any parameter measured. The deletion of ketanserin, leaving CID, did not alter treatment efficacy, except for a significant decline in cardiac index at 3 hours. Deletion of ibuprofen from CID resulted in a failure to reverse pulmonary arterial hypertension, hypoxemia, elevated EVLW, and increased SI. Removal of either cimetidine or diphenhydramine from CID resulted in significant increases in EVLW compared with control levels and SI compared with both control levels and CID. These results indicate that a combination of both histamine H1 and H2 receptor blockers and the cyclooxygenase inhibitor, ibuprofen, is effective and essential in the treatment of hypoxemia, early pulmonary hypertension, and pulmonary microvascular injury in this fulminant model of porcine Pseudomonas ARDS.

Animals↗

PubMed1987

Ibuprofen and methylprednisolone in a pig Pseudomonas ARDS model.

The effects of ibuprofen (I) and methylprednisolone (M) were studied in the Pseudomonas porcine model of adult respiratory distress syndrome (ARDS). Four groups of animals were anesthetized and ventilated with 0.5 FIO2, 5 cm PEEP, and 20 cc/kg tidal volume: a control group given saline alone; Pseudomonas infusion alone (P); Pseudomonas with ibuprofen (I), 12.5 mg/kg given at 20 and 120 min; and P with methylprednisolone (M), 30 mg/kg given at 20 and 120 min. We compared the alteration in pulmonary hemodynamics with the alteration in the plasma concentration of thromboxane (TxB2) and 6-keto PGF1 alpha in the treated and untreated groups. Hemodynamic parameters measured included the pulmonary (PAP) and systemic (SAP) arterial pressures, cardiac index (C1), thermal-cardiogreen extravascular lung water (EVLW), and PaO2. Albumin Flux was measured by a gamma scintigraphic method (slope index; SI). P produced a dramatic increase in PAP (P less than 0.05) with a progressive increase in EVLW and SI (P less than 0.05) and fall (P less than 0.05) in PaO2, CI, and SAP. The acute pulmonary hypertension was associated with a significant rise in TxB2 and 6-keto PGF1 alpha in the Pseudomonas group. I effectively blocked the elevation of TxB2 and caused a significant but transient improvement in PAP and rise in PaO2. Albumin flux and water leak as measured by SI and EVLW were not affected by ibuprofen. M reduced the elevation of TxB2 and 6-keto PGF1 alpha but failed to block these prostaglandins significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗

PubMed1984

Failure of methylprednisolone, ibuprofen, or prostacyclin to reduce HCl-induced pulmonary albumin leak in dogs.

The purpose of this study was to examine the effects of methylprednisolone (MP), ibuprofen (I), and prostacyclin (PGI2) pretreatment on cardiopulmonary hemodynamics, arterial oxygenation, and pulmonary alveolar-capillary membrane permeability, measured with a gamma-scintigraphic technique, after acid instillation in the dog. All animals were placed on their right side and 2 ml/kg 0.1 N HCl was instilled into the endotracheal tube. Five untreated control dogs showed a significant (p less than 0.05) rise in slope index (SI), a scintigraphic measurement of pulmonary albumin flux, 30 minutes after acid injury. After 120 minutes there was a significant rise in mean pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR) and a decrease (p less than 0.05) in cardiac output (CO) and PaO2. Two groups of five dogs each were pretreated with MP (30 mg/kg) and I (12.5 mg/kg), respectively. Thirty minutes after acid instillation both groups showed a significant rise in the SI, which was significantly greater than the values in the control animals in the case of MP. By 120 minutes after acid injury all changes in PAP, PVR, PaO2, and CO were not significantly different from those of control animals with the exception of the I group, which resisted any change in CO throughout the study. Another group of five dogs were pretreated with a constant infusion of PGI2 (3 micrograms/kg/min) starting 75 minutes before acid instillation. PGI2 produced a significant increase in CO that was also greater (p less than 0.05) than the CO in control animals before instillation of HCl. Pre-HCl SI in the dogs treated with PGI2 was slightly, but significantly, increased over control dogs. The SI and CO remained significantly higher than values in control animals 30 minutes after acid injury. The SI remained significantly higher than that of control animals at 120 minutes. After 2 hours changes in PAP, PVR, PaO2, and CO were without significant difference from those of control animals. These data support the conclusion that PGI2, I, or MP are not effective therapy for acid aspiration and that PGI2 and I may worsen the protein leak by increasing flow across the damaged capillary membrane.

Albumins↗

PubMed1983

Failure of various agents to decrease oleic acid pulmonary albumin leak.

Computerized pulmonary gamma scintigraphy has been shown to be a sensitive technique for the measurement of albumin flux in oleic acid pulmonary microvascular injury. In this technique technetium-99m-tagged human serum albumin is administered intravenously and lung:heart radioactivity ratios are constructed. This ratio remains constant unless there is a net flux of albumin from the vascular space into the lung, when a rising ratio is seen, called the "slope of injury" or SI. Gamma scintigraphy provides a method to rapidly screen the ability of various possible therapeutic agents to reduce the flux of albumin in experimental ARDS. In this study, 0.05 ml/kg oleic acid produced a significant increase in the SI. None of the agents tested (30 mg/kg methylprednisolone, 12.5 mg/kg ibuprofen, 4 mg/kg MK-447, a superoxide radical scavenger, or 140 mg/kg calcium gluconate) were able to alter the scintigraphically measured increased albumin flux produced by 0.05 ml/kg oleic acid.

Albumins↗