Search PubMed⌕ Search

Biomedical subjects

V Arroyo

Publications and source records attributed to V Arroyo.

At least 73 records · Page 4Linked to original sources
PubMed1997

Effect of therapeutic paracentesis on plasma volume and transvascular escape rate of albumin in patients with cirrhosis.

BACKGROUND/AIMS: Circulatory abnormalities with activation of vasoconstrictor systems after large-volume paracentesis are generally considered secondary to an increased extravasation of fluid from the intravascular compartment to the extravascular space with subsequent reduction in plasma volume. To test this hypothesis, plasma volume, the transvascular escape rate of albumin, the absolute escape rate of albumin and the activity of vasoconstrictor systems were measured in 25 cirrhotic patients with ascites in baseline conditions and 2 days after total paracentesis with plasma volume expansion. METHODS: Plasma volume and the transvascular escape rate of albumin, the fraction of albumin passing from the intravascular to the extravascular space per unit of time, were assessed through the plasma disappearance curve of radioiodinated human albumin. The absolute escape rate of albumin, the total flux of albumin from intravascular to extravascular space per unit of time, was also calculated. RESULTS: Eight of the 25 patients (32%) developed marked activation of vasoconstrictor systems after paracentesis. In these patients, plasma renin activity and plasma norepinephrine concentration increased from 6.6+/-2 to 23.4+/-11 ng x ml(-1) x h(-1) and 776+/-229 to 989+/-258 pg/ml, respectively (p<0.05). No significant changes in these parameters were found in the remaining 17 patients. The activation of vasoconstrictor systems occurred in the absence of changes in plasma volume (3456+/-276 vs 3476+/-264 ml, NS), transvascular escape rate of albumin (10.4+/-1 vs 10.9+/-2%/h, NS) and absolute escape rate of albumin (9.9+/-1.9 vs 10.5+/-0.7 g/h, NS). CONCLUSIONS: These results do not support a contraction of plasma volume as the mechanism responsible for activation of vasoconstrictor systems after paracentesis. Rather, the activation of vasoconstrictor systems in the absence of changes in plasma volume suggests that paracentesis accentuates the impairment of "effective" blood volume present in cirrhotic patients with ascites.

Blood Pressure↗
PubMed1997

Urinary endothelin-like immunoreactivity in patients with cirrhosis.

BACKGROUND/AIMS: To investigate a possible relationship between the renal production of endothelin and the presence of renal dysfunction and activation of vasoactive systems in cirrhosis, the urinary excretion and the circulating plasma levels of immunoreactive endothelin (irET) and the plasma levels of vasoactive hormones were measured in 19 healthy subjects, 12 cirrhotic patients without ascites and 39 patients with ascites and different degrees of renal dysfunction. METHODS: The urinary excretion and the circulating levels of irET were assessed after 5 days on a 40 mEq sodium diet and off diuretics. Renal function parameters and the plasma levels of vasoactive hormones were also measured. RESULTS: Patients with and without ascites had similar values of urinary irET as compared with healthy subjects (30+/-3, 31+/-3 and 29+/-2 ng/day, respectively, p>0.10). By contrast, patients with ascites had higher circulating levels of irET (15+/-1.2 pg/ml) than patients without ascites and healthy subjects (11+/-1.6 and 5+/-0.4 pg/ml, p<0.01). In patients with cirrhosis, no correlation was found between urinary irET and circulating irET. Moreover, urinary irET did not correlate with liver tests, serum and urine sodium, glomerular filtration rate or vasoactive substances. Patients with hepatorenal syndrome had similar urinary irET to patients with ascites without hepatorenal syndrome. CONCLUSIONS: Urinary excretion of irET is not increased in cirrhotic patients with ascites and does not correlate with abnormalities in renal function.

Adult↗
PubMed1997

Diuretic requirements after therapeutic paracentesis in non-azotemic patients with cirrhosis. A randomized double-blind trial of spironolactone versus placebo.

BACKGROUND/AIMS: Diuretic requirements after mobilization of ascites by paracentesis have never been assessed in cirrhosis. It is also unknown whether diuretics increase the incidence of postparacentesis circulatory dysfunction. The aim of this study was to investigate these features and to assess whether measurement of plasma renin activity and aldosterone prior to paracentesis predicts diuretic response after this procedure. METHODS: Thirty-six patients with non-azotemic cirrhosis and ascites treated by total paracentesis plus i.v. albumin were randomly assigned to receive placebo (n=17) or spironolactone 225 mg/day (n=19) immediately after paracentesis and followed-up for 4 weeks. RESULTS: Five patients (three in the placebo and two in the spironolactone group) abandoned the treatment prior to ascites recurrence or the end of the study due to complications or lack of compliance. The analysis was performed in the remaining 31 patients. Ascites recurrence was more common in the placebo group (13 cases, 93%) than in the spironolactone group (3 cases, 18%) (p<0.0001) and occurred within the first 2 weeks of follow-up in more than 50% of patients. Patients developing ascites in the spironolactone group had higher levels of renin (14.1, 20.6, 32.4 ng/ml per h) and aldosterone (120, 149, 288 ng/dl) than those who did not develop ascites (renin: 2.0+/-2.1 ng/ml per h; range 0.1-6.8; aldosterone: 43+/-38 ng/dl; range 4-116). Three patients in the placebo group and two in the spironolactone group developed postparacentesis circulatory dysfunction (defined as an increase in renin at the third day after paracentesis greater than 50% over baseline levels up to a value higher than 4 ng/ml per h). CONCLUSIONS: Patients with cirrhosis treated by paracentesis should receive diuretics immediately after this procedure to prevent early recurrence of ascites. The administration of 225 mg/day of spironolactone is a good empiric treatment for non-azotemic patients with cirrhosis, because it is effective in most cases and does not increase the incidence of postparacentesis circulatory dysfunction. The determination of plasma levels of renin or aldosterone prior to paracentesis predicts the efficacy of spironolactone in the prevention of ascites recurrence.

Aldosterone↗
PubMed1997

Ascites and renal functional abnormalities in cirrhosis. Pathogenesis and treatment.

In the past few years, there have been important advances in the field of pathogenesis and management of ascites and hepatorenal syndrome in cirrhosis. A new pathogenic theory of ascites and renal dysfunction in cirrhosis has been presented and previously ill-defined conditions, such as refractory ascites and hepatorenal syndrome, have been defined precisely. The link between the diseased liver and the disturbances in renal function and vasoactive systems is not completely known, but a large body of evidence indicates that it consists of a circulatory dysfunction that affects mainly the arterial circulation and is characterized by an inability to maintain an effective arterial blood volume within normal limits. The research on the mechanisms of this circulatory dysfunction will give valuable information in the design of more pathophysiologically oriented therapeutic approaches to the management of ascites.

Ascites↗
PubMed1997

Pathophysiology, complications, and treatment of ascites.

In the past few years, there have been important advances in the field of pathogenesis and management of ascites and spontaneous bacterial peritonitis in cirrhosis. A new pathogenic theory of ascites and renal dysfunction in cirrhosis has been presented, and previously ill-defined conditions, such as refractory ascites and hepatorenal syndrome, have been defined precisely. The reintroduction of therapeutic paracentesis has modified markedly the way in which patients hospitalized for ascites are treated. The use of potent and safe antibiotics has improved the resolution rate and survival of patients with spontaneous bacterial peritonitis, and the use of oral antibiotics will simplify the management of this condition in the near future. Finally, prophylactic antibiotic regimens represent a major step forward in the prevention of spontaneous bacterial peritonitis in subsets of cirrhotic patients with a great risk of developing this complication.

Ascites↗
PubMed1997

Nitric oxide production by peritoneal macrophages of cirrhotic rats: a host response against bacterial peritonitis.

BACKGROUND & AIMS: Patients and rats with cirrhosis and ascites are prone to develop peritonitis. The aim of this study was to assess whether peritoneal macrophages of cirrhotic rats without peritoneal infection produce nitric oxide and express inducible NO synthase (iNOS). METHODS: NO2- accumulation produced by macrophages from control rats and cirrhotic rats with ascites was determined. iNOS messenger RNA and protein expression were analyzed by Northern and Western blot and immunocytochemical analysis. The in vivo effects of inhibiting iNOS were investigated by giving the specific iNOS inhibitor L-N-(1-iminoethyl)-lysine (L-NIL) or sterile saline to 9 and 7 cirrhotic rats with ascites, respectively. RESULTS: Cirrhotic macrophages produced NO2- that was around fourfold greater than that of control macrophages after 30 hours in culture. Northern and Western blot and immunocytochemical analysis showed the presence of iNOS messenger RNA and protein in macrophages of cirrhotic rats. Ascites cultures were positive in all rats administered L-NIL and negative in those administered saline. CONCLUSIONS: Macrophages of cirrhotic rats produce NO and express iNOS messenger RNA and protein, and these changes are not a consequence of overt bacterial infection. Because iNOS inhibition results in peritoneal infection, these results suggest that iNOS induction in macrophages of cirrhotic rats is a host defense response to prevent bacterial peritonitis.

Animals↗
PubMed1997

Paracentesis-induced circulatory dysfunction: mechanism and effect on hepatic hemodynamics in cirrhosis.

BACKGROUND & AIMS: Therapeutic paracentesis may be associated with a circulatory dysfunction, manifested by a marked increase of the plasma renin activity and plasma norepinephrine. The aim of the study was to characterize the systemic and hepatic hemodynamic changes associated with paracentesis-induced circulatory dysfunction. METHODS: Changes in plasma renin, aldosterone, and norepinephrine, and in systemic and hepatic hemodynamics were assessed 1 hour and 6 days after complete mobilization of ascites in 37 patients treated by total paracentesis plus intravenous dextran-70 infusion. RESULTS: Paracentesis-induced circulatory dysfunction occurred in 10 patients (renin and norepinephrine increased from 9.0 +/- 10.5 to 28.8 +/- 19.0 ng.mL-1.h-1 and from 752.0 +/- 364.0 to 1223.0 +/- 294.0 pg/mL, respectively) and was associated with significant reduction in systemic vascular resistance (-13.0% +/- 2.6%; P < 0.05) and increase in hepatic venous pressure gradient (from 19.5 +/- 1.5 to 22.5 +/- 2.4 mm Hg; P < 0.01). In the remaining 27 patients, mobilization of ascites also induced a significant but smaller reduction in systemic vascular resistance (-5.0% +/- 1.6%; P < 0.05) without significant changes in renin, norepinephrine, and hepatic venous pressure gradient. CONCLUSIONS: Paracentesis-induced circulatory dysfunction is predominantly caused by an accentuation of the arteriolar vasodilation already present in untreated cirrhotic patients with ascites. The homeostatic activation of endogenous vasoactive systems may account for the increased intrahepatic vascular resistance associated with this condition.

Aged↗
PubMed1997

Arginine vasopressin induces contraction and stimulates growth of cultured human hepatic stellate cells.

BACKGROUND & AIMS: Hepatic stellate cells (HSCs) are perisinusoidal cells believed to participate in the regulation of hepatic blood flow because of their contractile properties and presence of receptors for several vasoactive factors. It is unknown whether HSCs have receptors for vasopressin, one of the most potent endogenous vasoconstrictors. This study investigated the existence of receptors for and the effects of arginine vasopressin (AVP) on cultured human HSCs. METHODS: intracellular calcium concentration ([Ca2+]i) and cell contraction were measured in individual cells loaded with fura-2 using a morphometric method with an epifluorescence microscope coupled to a CCD imaging system (Photometrics, Tucson, AZ). AVP-specific binding was measured with [3H]AVP. Mitogen-activated protein kinase (MAPk) activity and DNA synthesis were measured by in vitro phosphorylation of myelin basic protein and [3H]thymidine incorporation, respectively. Parallel experiments were performed in vascular smooth muscle cells. RESULTS: AVP elicited a dose-dependent increase in [Ca2+]i and contraction of HSCs. Moreover, AVP increased MAPk activity, DNA synthesis, and cell number. These effects were similar to those observed in vascular smooth muscle cells and were blocked by a V1 receptor antagonist. The existence of V1 receptors was further confirmed by binding studies. CONCLUSIONS: Human HSCs have V1-vasopressin receptors that induce effects similar to those observed in vascular smooth muscle cells. AVP may play a role in the regulation of HSC function.

Animals↗
PubMed1997

Pathogenesis of ascites in cirrhosis.

Much progress has been made in the recognition of factors involved in the pathogenesis of the abnormal regulation of extracellular fluid volume in cirrhosis. It is now well established that cirrhosis induces modifications in the activity of several systemic vasoactive factors which then play a major role in the development of renal dysfunction and the formation of ascites and edema. It is also evident that intrarenal factors participate in the pathogenesis of these abnormalities. Nevertheless, the available information is still limited. The link between the diseased liver and the disturbances in the vasoactive systems is not completely known but much evidence suggests that it consists of a circulatory dysfunction that affects mainly the arterial circulation and is characterized by an inability to maintain an effective arterial blood volume within normal limits. Research on the mechanisms of this circulatory dysfunction may yield clues that will help in the design of more pathophysiologically oriented therapeutic approaches to the management of ascites.

Ascites↗
PubMed1997

Hepatorenal syndrome.

Hepatorenal syndrome is a common complication in patients with advanced cirrhosis and ascites characterized not only by renal failure but also by marked alterations in systemic hemodynamics and vasoactive systems. Renal failure is due to a marked hypoperfusion of the kidney secondary to renal vasoconstriction. The pathogenesis of hepatorenal syndrome is not completely known but it is thought to be the extreme manifestation of the underfilling of the arterial circulation secondary to an arterial vasodilation, located mainly in the splanchnic circulation. Recently, a new definition and diagnostic criteria of hepatorenal syndrome have been proposed, which has stimulated research in this field. Prognosis of patients with hepatorenal syndrome is very poor. Liver transplantation is the only effective treatment but it is not applicable in all patients due to short survival. New therapies developed during the last few years, such as the use of systemic vasoconstrictors or transjugular intrahepatic portosystemic shunts appear promising, but their usefulness should be evaluated in prospective investigations.

Ascites↗
PubMed1997

Management of ascites in cirrhosis.

Ascites is one of the earliest and most common complications of patients with cirrhosis. A typical circulatory dysfunction characterized by arterial vasodilation, high cardiac output and stimulation of vasoactive systems is commonly present in these patients and is associated with a poor prognosis. The treatment of ascites has been based on the combination of a low-sodium diet and the administration of diuretics. The reintroduction of paracentesis and the recent introduction of the transjugular intrahepatic portosystemic shunt (TIPS) are the most relevant innovations in the treatment of ascites during the past two decades, although controlled trials in large series of patients are needed to delineate whether TIPS is a safe and useful treatment for these patients.

Ascites↗
PubMed1997

Practical recommendations for the treatment of ascites and its complications.

Ascites is one of the earliest and most common complications of patients with cirrhosis, and is associated with complications such as dilutional hyponatraemia, renal dysfunction and spontaneous bacterial peritonitis. The treatment of ascites has been based on the combination of a low-sodium diet and the administration of diuretics. The reintroduction of paracentesis and the recent introduction of the transjugular intrahepatic portosystemic shunt (TIPS) are the most relevant innovations in the treatment of ascites during the past 2 decades. The development of ascites is closely related to renal disturbances of functional origin, including the hepatorenal syndrome. A new definition of hepatorenal syndrome has been proposed recently and 2 different types have been defined (type I or progressive, and type III or stable). Although no effective therapy exists for this syndrome, the use of therapeutic methods (TIPS, vasoconstrictor agents, dialysis) to temporarily improve renal function and act as a 'bridge' to liver transplantation, may be of most benefit. The use of potent and safe antibiotics has improved the resolution rate and survival of patients with spontaneous bacterial peritonitis. In addition, the use of oral antibiotics will simplify the management of this condition in the near future. Finally, prophylactic antibiotic regimens represent a major step forwards in the prevention of spontaneous bacterial peritonitis in subsets of cirrhotic patients with a great risk of developing this complication.

Anti-Bacterial Agents↗
PubMed1997

[Current treatment of ascites and spontaneous bacterial peritonitis in Spain: analysis of a survey of gastroenterologists and hepatologists].

During the XXII Congress of the Spanish Association for the Study of the Liver a questionnaire was distributed with the aim of describing the current therapeutic attitude of those attending the meeting, concerning two of the most frequent complications of cirrhosis: ascites and spontaneous bacterial peritonitis (SBP). One hundred twelve of the 135 physicians who answered the questionnaire (83%) use to treat tense ascites by therapeutic paracentesis, while 86 physicians (63.7%) managed moderate ascites with diuretics, with spironolactone being the drug most commonly used (n = 117; 87.3%). The most used diuretic schedule for the treatment of ascites was the isolated administration of spironolactone. Frusemide was associated with spironolactone only when moderate or high doses of the latter were found to be insufficient for increasing urinary sodium excretion and eliminating ascites. Following therapeutic paracentesis however, 79 of those surveyed (58.3%) administered a combination of both diuretics on initiation to avoid reaccumulation of ascitic fluid. Sixty-eight of the physicians (50.3%) used transhepatic intrajugular portosystemic shunt in the treatment of refractory ascites. Cefotaxime was the antibiotic most widely used in the treatment of SBP (n = 119; 88%). Most of the physicians surveyed performed prophylaxis of this infection (generally by the oral administration of norfloxacin) in patients with a previous history of SBP (n = 125; 92.6%) or an episode of gastrointestinal hemorrhage (n = 108; 80%) but not in those patients with no previous history of SBP and with low protein concentrations in the ascitic fluid (n = 40; 29.6%). On the appearance of SBP in patients undergoing prophylactic treatment, cefotaxime remained the antibiotic of choice (n = 104; 79%).

Ascites↗
PubMed1996

Urinary excretion of urodilatin in patients with cirrhosis.

Cirrhotic patients with ascites show increased plasma levels of natriuretic peptides from cardiac origin (i.e., atrial natriuretic peptide [ANP] and brain natriuretic peptide [BNP]). Urodilatin is a unique member of the natriuretic peptide family because it is exclusively synthesized in the kidney acting on a paracrine fashion in the regulation of sodium excretion. To investigate the renal production of urodilatin in cirrhosis and its relationship with other natriuretic peptides and sodium retention, urodilatin excretion and plasma levels of ANP were measured in 21 healthy subjects, 13 cirrhotic patients without ascites and 23 cirrhotic patients with ascites. Urine urodilatin was measured with a highly specific radioimmunoassay using a polyclonal antibody against human urodilatin. Patients with ascites had marked sodium retention (UNa 7 +/- 2 mEq/d) as compared to patients without ascites and healthy subjects (29 +/- 3 mEq/d and 34 +/- 5 mEq/d, respectively, P < .001). Patients with cirrhosis and ascites had urine urodilatin excretion similar to patients without ascites and healthy subjects (82 +/- 8 pmol/g, 95 +/- 10 pmol/g, and 89 +/- 9 pmol/ g of creatinine, respectively; not significant). In addition, immunoreactive urodilatin from cirrhotic patients with ascites and healthy subjects showed a similar chromatographic pattern. By contrast, plasma ANP levels were increased significantly in patients with ascites (29 +/- 3 fmol/mL) as compared with patients without ascites or healthy subjects (14 +/- 3 fmol/mL and 6 +/- 1 fmol/mL, respectively; P < .01). In conclusion, urine urodilatin excretion is normal in patients with cirrhosis even in the presence of marked sodium retention. The coexistence of increased ANP levels and normal urodilatin excretion suggests that in cirrhosis both natriuretic peptides are regulated independently.

Aldosterone↗
PubMed1996

Randomized trial comparing albumin, dextran 70, and polygeline in cirrhotic patients with ascites treated by paracentesis.

BACKGROUND & AIMS: Paracentesis associated with plasma expanders is widely used for the treatment of ascites in cirrhosis. This study investigated the clinical importance of paracentesis-induced-circulatory dysfunction and compared the efficacy of albumin, dextran 70, and polygeline in preventing this complication. METHODS: A total of 289 cirrhotic patients with ascites were randomized to treatment by total paracentesis plus intravenous albumin (97 patients), dextran 70 (93 patients), or polygeline (99 patients). Postparacentesis circulatory dysfunction was defined as an increase in plasma renin activity on the sixth day after paracentesis of more than 50% of the pretreatment value to a level > 4 ng.mL-1.h-1. RESULTS: Postparacentesis circulatory dysfunction occurred more frequently in patients treated with dextran 70 (34.4%; P = 0.018) or polygeline (37.8%; P = 0.004) than in those receiving albumin (18.5%). The plasma expander used and the volume of ascites removed were independent predictors of this complication. Postparacentesis circulatory dysfunction persisted during follow-up and was associated with a shorter time to first readmission (1.3 +/- 0.5 vs. 3.5 +/- 0.8 months, median +/- SEM; P = 0.03) and shorter survival (9.3 +/- 4.2 vs. 16.9 +/- 4.3 months; P = 0.01). Creatinine and sodium levels in serum, and Child-Pugh score at inclusion, and postparacentesis circulatory dysfunction were independent predictors of survival. CONCLUSIONS: Postparacentesis circulatory dysfunction is not spontaneously reversible and is associated with a shorter time to first readmission and shorter survival. Albumin is the best plasma expander to prevent this complication.

Adult↗