Capnography is superior to pulse oximetry for the detection of respiratory depression during colonoscopy.

BACKGROUND: Pulse oximetry is a widely accepted procedure for ventilatory monitoring during gastrointestinal endoscopy, but this method provides an indirect measurement of the respiratory function. In addition, detection of abnormal ventilatory activity can be delayed, especially if supplemental oxygen is provided. Capnography offers continuous real-time measurement of expiratory carbon dioxide. OBJECTIVE: We aimed at prospectively examining the advantages of capnography over the standard pulse oximetry monitoring during sedated colonoscopies. PATIENTS AND METHODS: Fifty patients undergoing colonoscopy were simultaneously monitored with pulse oximetry and capnography by using two different devices in each patient. Several sedation regimens were administered. Episodes of apnea or hypoventilation detected by capnography were compared with the occurrence of hypoxemia. RESULTS: Twenty-nine episodes of disordered respiration occurred in 16 patients (mean duration 54.4 seconds). Only 38% of apnea or hypoventilation episodes were detected by pulse oximetry. A mean delay of 38.6 seconds was observed in the events detected by pulse oximetry (two episodes of disturbed ventilation were simultaneously detected by capnography and pulse oximetry). CONCLUSIONS: Apnea or hypoventilation commonly occurs during colonoscopy with sedation. Capnography is more reliable than pulse oximetry in early detection of respiratory depression in this setting.

[Effect of pentoxifylline on survival, cardiac function and both portal and systemic hemodynamics in advanced alcoholic cirrhosis--a randomized double-blind placebo-controlled trial]. / Effecto de la pentoxifilina en la supervivencia, la función cardiaca y en la hemodinámica portal y sistémica de la cirrosis alcohólica avanzada.

OBJECTIVE: To assess the effect of pentoxiphylline (a potent inhibitor of tumor necrosis factor alpha) on survival, on systemic and portal hemodynamics, and on cardiac function in patients with alcoholic cirrhosis. DESIGN: A randomized double-blind placebo-controlled trial. SETTING: A single center using parallel groups of patients to compare pentoxiphylline with placebo. PATIENTS: We recruited 24 patients with alcoholic cirrhosis (8 Child-Pugh B and 16 Child-Pugh C). INTERVENTIONS: Patients were randomly assigned to receive pentoxiphylline (400 mg tid; n = 12) or placebo (n = 12) over a 4-week period. OUTCOME MEASURES: The primary outcome was to extend short-term and long-term survival. Secondary outcomes included hemodynamic benefits (improvement in cardiac function and/or systemic vascular resistance index, or decrease in portal pressure). RESULTS: Portal pressure and cardiac function remained unchanged and there were no significant differences in short-term or long-term survival between treatment and placebo groups. The group on pentoxiphylline increased systemic vascular resistance and decreased cardiac indices (from 1,721 +/- 567 to 2,082 +/- 622 dyn.sec(-1) cm(-5) m(-2) and from 4.17 +/- 1.4 to 3.4 +/- 0.9 l.m(-2), p = 0.05). CONCLUSIONS: Although pentoxiphylline seems to provide some short-term hemodynamic benefits in patients with advanced alcoholic cirrhosis, this drug has no effect on survival or portal pressure in these patients.

Long-term reversal of hypocholesterolaemia in patients with chronic hepatitis C is related to sustained viral response and viral genotype.

BACKGROUND: Genotype-3 of hepatitis C virus (HCV) has been associated with serum lipid changes (reversible with sustained viral response) and liver steatosis. AIM: To characterize the relationships among hepatic steatosis, cholesterol and sustained viral response in these patients. METHODS: Patients (n = 215) with chronic hepatitis C (157 with genotype-1 of HCV) had age, body mass index, gender, alcohol intake, glycaemia, serum lipids, transaminases, grade and stage (METAVIR and Scheuer), degree of liver steatosis, sustained viral response, insulinaemia, leptinaemia, beta-hydroxybutyrate and glycerol measured, and were compared with 32 hepatitis B virus (HBV)-infected subjects. RESULTS: Genotype-3 of HCV patients had age-adjusted hypocholesterolaemia and more frequent hepatic steatosis (P < 0.001). Steatosis was inversely correlated with serum cholesterol (P < 0.01) and directly with viral load (P < 0.03). In patients with genotype-3 of HCV and sustained viral response, serum cholesterol increased from 138 (95% CI: 120-151) to 180 mg/dL (95% CI: 171-199) 12 months after treatment conclusion (P < 0.0001). By contrast, cholesterol values were unchanged in genotype-3 of HCV non-responders and in patients with genotype-1 of HCV regardless of response. Rising cholesterol in sustained viral response did not parallel the changes in beta-hydroxybutyrate. CONCLUSIONS: Besides causing hepatic steatosis, genotype-3 specifically decreases serum cholesterol. This interference with the metabolic lipid pathway is related to viral load, is reversed with sustained viral response, and seems unrelated to mitochondrial dysfunction.

Diagnostic and therapeutic approach to cholestatic liver disease.

When cholestatic liver disease is present, liver ultrasound should be performed to ascertain if cholestasis is extrahepatic or intrahepatic. If bile ducts appear dilated and the probability of interventional treatment is high, endoscopic retrograde cholagio-pancreatography (ERCP) or trans-hepatic cholangiography (THC) should be the next step. If the probability of interventional therapeutics is low, cholangio-MRI should be performed. Once bile duct dilation and space occupying lesions are excluded, a work up for intrahepatic cholestasis should be started. Some specific clinical situations may be helpful in the diagnostic strategy. If cholestasis occurs in the elderly, drug-induced cholestatic disease should be suspected, whereas if it occurs in young people with risk factors, cholestatic viral hepatitis is the most likely diagnosis. During the first trimester of pregnancy cholestasis may occur in hyperemesis gravidorum, and in the third trimester of gestation cholestasis of pregnancy should be suspected. A familial history of recurrent cholestasis points to benign recurrent intrahepatic cholestasis. The occurrence of intrahepatic cholestasis in a middle-aged woman is a frequent presentation of primary biliary cirrhosis, whereas primary sclerosing cholangitis should be suspected in young males with inflammatory bowel disease. The presence of vascular spider nevi, ascites, and a history of alcohol abuse should point to alcoholic hepatitis. Neonatal cholestasis syndromes include CMV, toxoplasma and rubinfections or metabolic defects such as cystic fibrosis, alpha1-antitrypsin deficiency, bile acid synthesis defects, or biliary atresia. The treatment of cholestasis should include a management of complications such as pruritus, osteopenia and correction of fat soluble vitamin deficiencies. When hepatocellular failure or portal hypertension-related complications occur, liver transplantation should be considered.

Disturbed synthesis of insulinlike growth factor I and its binding proteins may influence renal function changes in liver cirrhosis.

Insulinlike growth factor-1 (IGF-1) is an anabolic hormone synthesized by the liver upon stimulation by growth hormone (GH). IGF-1 exerts important effects on renal hemodynamics and renal sodium handling. The bioactivity of this hormone is influenced by its binding proteins (BP) of which IGF-BP3 favors retention in the capillary lumen while IGF-BP1 facilitates the transport to the target tissues. IGF-BP1 modulates the actions of IGF-1 on target cells including renal tubules. Although a number of reports have dealt with disturbances of the IGF-1/IGF-BP system in cirrhosis, no studies have yet addressed the relationship between alterations in this system and renal function changes in cirrhosis. In the present study we have included 20 patients with cirrhosis and 10 healthy subjects (control group). As compared with the controls, patients showed lower circulating levels of IGF-1 and IGF-BP3, higher IGF-BP1 levels, and a tendency to higher insulinemia and GH values. The index IGF-1 x IGF-BP1/IGF-BP3 (IGF-1-IGF-BP index, reflecting the accessibility of circulating IGF-1 to target cells) was higher in patients with ascites. IGF-1 directly correlated with renal blood flow (P < 0.05), with IGF-BP3 (P < 0.001) and inversely with the Pugh's score (P < 0.02). A negative correlation was found between IGF-1-IGF-BP index and fractional sodium excretion (P < 0.01) and between IGF-BP1 and urinary sodium excretion (P < 0.02). Our findings support the hypothesis that the disturbance of the IGF-1/IGF-BP axis may be related to the degree of renal vasodilation and renal sodium retention in cirrhotic patients.

Continuous prazosin administration in cirrhotic patients: effects on portal hemodynamics and on liver and renal function.

BACKGROUND & AIMS: Hepatic vascular resistance is influenced by alpha-adrenergic tone. The aim of this study was to investigate the effects of continuous blockade of alpha-adrenoceptors with prazosin on hemodynamics, liver function, and renal function and whether the association of propranolol or furosemide enhances the portal pressure lowering effect of prazosin. METHODS: Cirrhotic patients with portal hypertension were studied at baseline and after a 3-month course of prazosin (n = 18) or placebo (n = 10). RESULTS: No changes were observed in the placebo group. Prazosin decreased the hepatic venous pressure gradient (HVPG) while increasing hepatic blood flow. Liver function improved as shown by an increase in hepatic and intrinsic hepatic clearances of indocyanine green and galactose elimination capacity. A significant reduction in mean arterial pressure and systemic vascular resistance was associated with increases in plasma renin activity and aldosterone concentration and a decrease in glomerular filtration rate. The plasma volume increased significantly, and 6 patients developed edema. The association of propranolol (n = 8) but not furosemide (n = 7) to prazosin increased the reduction in HVPG and attenuated the increase in plasma renin activity. CONCLUSIONS: In cirrhotic patients, continuous prazosin administration reduces portal pressure and improves liver perfusion and function but favors sodium and water retention. The association of propranolol enhances the decrease in portal pressure, suggesting a potential benefit from this combined therapy.

Hemodynamic effects of alpha-adrenergic blockade with prazosin in cirrhotic patients with portal hypertension.

This study was aimed at investigating whether the blockade of alpha 1-adrenergic receptors could reduce portal pressure in cirrhosis. Splanchnic and systemic hemodynamics were measured in 12 cirrhotic patients with esophageal varices at baseline and 1 hr after oral administration of 2 mg of prazosin (acute study). Measurements were repeated in 10 of these 12 patients after a 3-mo course of 5 mg/12 hr of prazosin (long-term study). Short-term prazosin significantly lowered the hepatic venous pressure gradient from 20.1 +/- 1.3 to 14.4 +/- 0.9 mm Hg (-25.7%) (p < 0.01), and chronic prazosin reduced it to 16.5 +/- 1.3 mm Hg (-19.1%) (p < 0.01). Hepatic blood flow was increased, thus changes in the hepatic venous pressure gradient resulted from a reduction in the estimated hepatic vascular resistance. Reductions in hepatic venous pressure gradient achieved after short-term and long-term prazosin were not significantly different. Reductions in mean arterial pressure and systemic vascular resistance were significantly greater after short-term than after long-term prazosin. Long-term prazosin was associated with significant increases in hepatic and intrinsic hepatic clearances of indocyanine green. This therapy also led to an increase in pulmonary capillary pressure (+ 28.6%, p < 0.05) and body weight (+ 3.06%, p < 0.01) and a decrease in hematocrit (-6.1%, p < 0.05) and urinary sodium excretion (-22.6%, p < 0.05). In contrast, there were no hemodynamic changes in a group of six cirrhotic patients receiving placebo. In cirrhotic patients, short-term prazosin lowers portal pressure by decreasing hepatic vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Octreotide prevents postprandial splanchnic hyperemia in patients with portal hypertension.

An increase in splanchnic blood flow is a physiological response to food intake. In patients with cirrhosis whose hepatic vascular resistance is already high, this increase in flow leads to marked increases in portal pressure. This study investigates whether octreotide prevents the increases in hepatic flow and portal pressure that follow the ingestion of a meal in patients with cirrhosis. Twenty-two patients with cirrhosis and portal hypertension were randomized to receive a mixed liquid meal (520 kcal) plus a single subcutaneous injection of either placebo or octreotide (200 micrograms). In the placebo group the ingestion of a meal was followed by an increase in the hepatic venous pressure gradient (+ 19.4 +/- 4.3%, p < 0.01) and hepatic blood flow (+ 38.2 +/- 14.6%, p < 0.05) at 30 min. In contrast, in the octreotide group eating caused no significant change in the hepatic venous pressure gradient (-2.8 +/- 3.6%, NS), while hepatic flow was decreased (-6.08 +/- 5.4%, p < 0.05). Octreotide blunted the postprandial increase in serum insulin and glucagon levels observed in the placebo group. In conclusion, in patients with cirrhosis and portal hypertension, octreotide prevents the postprandial increase in hepatic blood flow, and consequently also in portal pressure. These findings suggest that this drug could play a role in the long-term management of portal hypertension.