Influence of an upright body position on the size of intrapulmonary blood shunts in patients with advanced liver cirrhosis.

Hepatopulmonary syndrome (HPS) is a complication of liver cirrhosis and is responsible for chronic hypoxemia and its negative health consequences. The most relevant diagnostic criterion of HPS is evidence of pathological intrapulmonary blood shunting (IPBS). There is still insufficient knowledge about the subclinical forms of HPS. The aim of this study was to determine whether an erect posture in patients with liver cirrhosis had a significant effect on IPBS, the diagnosis of HPS and oxygen saturation. Thirty cirrhotic patients considered for liver transplantation were enrolled in this study. Pulse oximetry and lung perfusion scintigraphy were conducted in patients while they were in supine and upright body positions. Pathological IPBS was observed in 16% and 20% of patients examined in the supine and upright body positions, respectively (mean difference 0.59%; P = 0.046). Postural-related IPBS changes were markedly greater in patients with HPS (1.76%; P = 0.011). Oxygen saturation was significantly lower in the erect posture compared to the supine posture (mean difference 1.2%; P = 0.02); however, there was no relationship between oxygen saturation and IPBS. In conclusion, an erect posture in patients with advanced liver cirrhosis leads to a subtle increase in IPBS, which is more pronounced in patients with HPS, and oxygen saturation measurements are not sensitive enough to detect these changes.

Usefulness of thoracic electrical bioimpedance in detection of ejection fraction changes.

The aim of this study was to evaluate a usefulness of thoracic electrical bioimpedance (TEB) in following adaptive haemodynamic adjustments to postural change and isometric exercise. Sixteen subjects with intact cardiovascular system took part in this study. Haemodynamic parameters were obtained in recumbency and after taking up erect posture. Besides, TEB was performed during handgrip test and the results were compared with baseline resting data. Each time the radionuclide ventriculography (RV) was performed concurrently with TEB to obtain an independent measurement of ejection fraction (EF). Active orthostasis was associated with a change in stroke volume, cardiac output and total vascular resistance by -29.7%, -3.4%, +3.9%, respectively. The handgrip produced a significant increase in cardiac output by 16.3%, however it was not associated with an enhancement of stroke volume. Although there was a moderate correlation between EF calculated by TEB and RV in supine position (r=0.66; p < 0.001), TEB failed to reflect changes of EF in orthostasis and isometric exercise. In conclusion, our results suggest that TEB offers in subjects with normal cardiovascular function a valuable alternative to cardiovascular monitoring of stroke volume and cardiac output, but calculation of EF is associated with a risk of serious error.

Radionuclide studies on gastric evacuatory function in health and in the duodenal ulcer disease. II. Regional distribution of emptying index (RDEI) patterns.

Studies with a new method for visualizing the stomach evacuatory function - regional distribution of emptying index (RDEI) were performed on 35 healthy subjects and 34 duodenal ulcer patients. The observed gastric RDEI patterns are described in detail, and their pathophysiological meaning is discussed. A significantly higher incidence of an atypical gastric RDEI pattern was found in duodenal ulcer patients compared to normals. Except for a shorter disease duration, however, no other clinical features distinguished the patients with the present atypical gastric RDEI pattern from the remaining ones. It has been hypothesized that antral dysmotility is a cause of the observed phenomenon.

Focal liver disease: neural network-aided diagnosis based on clinical and laboratory data.

OBJECTIVES: The purpose of this study was to evaluate the use of clinical and laboratory data in the diagnosis of benign or malignant focal liver disease. METHODS: Diagnosis was made by artificial neural network (NN), a system of simple computing units connected in a specific structural network. Seven clinical and laboratory variables were retrospectively studied in 172 patients with a liver mass (93 benign, 79 malignant) detected with ultrasound. The diagnostic efficacy of NN was compared with a score based on the logistic regression model (Beaujon score). RESULTS: Although the sensitivity of the Beaujon score and the neural network was similar (4 malignant tumors inversely classified), neural network-aided diagnosis was characterized by higher specificity and accuracy (respectively 98.9% vs 82.5%, P < 0.001, and 97.1% vs 88.4%, P < 0.002). CONCLUSION: In patients with a hepatic mass, neural network is a valuable method for differentiating malignant and benign tumors.

Segmental mean transit times of 99mtechnetium within central vascular space in liver cirrhosis.

Mean transit time (MTT) through a given vascular space is closely related to the effective blood volume in this compartment. Central vascular blood volume in liver cirrhosis is believed to be reduced, but more precise data on the location of the underfilled vascular area are lacking. 99mTechnetium first-pass angiography was performed in 15 cirrhotic patients and in 10 age-matched normals. The method of segmental analysis of MTT was validated by performing an analog study in a plastic tubing/chamber system. The mean tracer sojourn in the central circulation was described in cirrhotic patients (10.25 +/- 2.17 s vs 12.92 +/- 2.88 s; p less than 0.05); however, this finding was not observed beyond cardiopulmonary circulation (MTT between right and left heart chambers). Segmental comparative analysis between cirrhotics and normals revealed significant MTT differences in two vascular subcompartments, i.e. right chamber-pulmonary artery, and within the lung vascular bed. Analysis of time activity lung curves in patients with cirrhosis disclosed a shorter time to peak and more rapid washout of the tracer from this area, without any change in curve symmetry as compared to normals. Ascites had no apparent impact on MTT rate, and cirrhotics with most advanced disease (grade C Child-Pugh) had longer MTT through the cardiopulmonary circulation as compared to combined groups A & B (7.32 +/- 0.13 s vs 6.03 +/- 1.23 s; p less than 0.05). Our data provide further evidence for contraction of the cardiopulmonary vascular space in liver cirrhosis.

Inhibitory effect of cigarette smoking on gastric emptying of a solid meal in patients with type I gastric ulcer.

The effect of cigarette smoking on gastric emptying (GE) of a radio-labelled solid meal was examined in 14 patients with type I gastric ulcer diagnosed at endoscopy. The patients underwent GE measurement thrice: under basal conditions and for two smoking sessions--without and after cimetidine pretreatment (2 x 400 mg orally for 2 days and 400 mg orally 1.5 h before the isotopic GE examination). Cigarette smoking significantly delayed GE--the median GE index, Ix: 0.688 min-1.10-2 (range 0.033-1.886) after smoking vs. 1.246 min-1.-2 (range 0.384-2.339) under basal conditions, p less than 0.01. The inhibitory effect of smoking on solid GE was blunted when smoking coincided with cimetidine pretreatment--the median Ix amounted to 1.069 min-1.10-2 (range 0.022-1.462) and was not significantly different from that under basal conditions.

[Per-rectal scintigraphy of the portal system with pertechnetate TC-99M: effect of propranolol on portosystemic collateral circulation in patients with cirrhosis. Part II]. / Przezodbytnicza scyntygrafia ukladu wrotnego nadtechnecjanem TC-99M: wplyw propranololu na wrotno-systemowe krazenie oboczne u chorych z marskoscia watroby. Czesc II.

Propranolol can reduce portal hypertension, therefore is recommended in prevention of variceal bleeding in patients with liver cirrhosis. However, in certain patients with cirrhosis portal hypotensive effect of propranolol cannot be obtained, and the reason of this finding is unknown. In 28 patients with cirrhosis the effect of seven days administration of propranolol on collateral blood flow from inferior mesenteric vein was examined by means of per-rectal portal scintigraphy. Portosystemic shunt index was significantly reduced by propranolol by 17.4 +/- 4.8%. This reduction was observed in cirrhotics classified to A and B, but not C Child-Pugh. These data suggest that propranolol increases vascular resistance in portosystemic circulation which depends on severity of liver failure. This mechanism opposes reduction of portal pressure.

[Per-rectal scintigraphy of the portal system with pertechnetate TC-99M: clinically useful examination of patients with chronic liver disease.Part I]. / Przezodbytnicza scyntygrafia ukladu wrotnego nadtechnecjanem TC-99M: kliniczna przydatnosc badania u chorych z przewleklymi chorobami watroby. Czesc I.

Per-rectal portal scintigraphy with Tc-99m pertechnetate is a method to evaluate portosystemic shunting (shunt index) in inferior mesenteric vein. In this study the shunt index was estimated in patients with chronic liver disease in relation to the severity of liver injury, portal hypertension and incidence of oesophageal varices. Shunt index was elevated in patients with non-cirrhotic liver disease as compared with healthy normals (34 +/- 6% vs 8 +/- 2%; p < 0.0005). Moreover, patients with cirrhosis had the shunt index of 65 +/- 4% which was higher than in other groups. There was no correlation of the shunt index to the Child-Pugh classification, hepatic venous pressure gradient and varices size in the cirrhotic patients. Conversely, the shunt index differentiated variceal bleeders from non-bleeders (80 +/- 4% vx 59 +/- 6%; p < 0.005). These data show that peripheral collateral circulation develop in response to mild elevation of portal pressure, but its hemodynamic efficacy to alleviate portal hypertension seems to be unremarkable. High shunt index might reflect elevated risk of bleeding from varices.

Portal shunting in inferior mesenteric vein in cirrhosis: correlation with hemorrhage from esophageal varices.

OBJECTIVE: Certain patients with portal hypertension develop large esophageal varices, whereas others have small varices, or none. Our objective in this study was to determine whether this variability depends upon the amount of blood derived by peripheral portosystemic collaterals. METHODS: Esophagogastroscopy to determine presence and size of esophageal varices, and pre-rectal portal scintigraphy to assess portosystemic shunt index (PSI) in inferior mesenteric vein were performed in 45 cirrhotics and 17 patients with pre-cirrhotic liver disease. RESULTS: Patients with cirrhosis had higher PSI than normal controls (67 +/- 4 vs. 8 +/- 2%; p < 0.0001) and pre-cirrhotic patients (vs. 34 +/- 6%; p < 0.0001). Neither variceal size nor PSI was correlated with Child-Pugh classification or hepatic venous pressure gradient. PSI was not related to the presence of varices or their size. On the other hand, patients with variceal hemorrhage had elevated PSI, compared with non-bleeders (80 +/- 4% vs. 59 +/- 6%; p < 0.005). CONCLUSIONS: This study shows that portosystemic collaterals in the inferior mesenteric vein do not prevent the formation of large varices. Furthermore, the magnitude of blood flow through peripheral collaterals might reflect the risk of variceal hemorrhage.

Effect of propranolol on portosystemic collateral circulation estimated by per-rectal portal scintigraphy with technetium-99m pertechnetate.

BACKGROUND/AIMS: Propranolol is widely used in the prevention of variceal bleeding. However, in certain patients with cirrhosis, the portal hypotensive effect of propranolol cannot be obtained. An explanation for portal unresponsiveness to propranolol could be an increase in portocollateral vascular resistance mediated by this drug. METHODS: In 33 patients with cirrhosis the effect of chronic administration of propranolol on portocollateral blood flow from the inferior mesenteric vein was examined by means of per-rectal portal Tc-99m pertechnetate scintigraphy. RESULTS: Propranolol significantly reduced the shunt index by 15.3 +/- 4.2%. This reduction was observed only in patients with cirrhosis classified as Child-Pugh A and B groups, but not group C. Differences between groups in portosystemic shunt index changes after propranolol were significant (F = 3.4, p < 0.05). CONCLUSIONS: The data presented suggest that propranolol changes the distribution of blood between the portal and systemic circulation, which is probably due to the increase in vascular resistance of portocollateral vessels. The magnitude of the vascular response to propranolol depends on the severity of liver disease.

Cardiovascular status after postural change in compensated cirrhosis: an argument for vasodilatory concept.

It seems that hypervolemia and vasodilatation coincide in compensated cirrhosis, but neither rank nor importance of these factors has been fully clarified in adaptive response to postural change. We studied, with gated equilibrium radionuclide angiography and thoracic electrical bioimpedance the hemodynamic status of 19 patients with compensated cirrhosis and 18 healthy subjects in upright and supine positions. In the upright position, the cirrhotic patients were hypotensive and had decreased peripheral vascular resistance despite increased cardiac output. The transition to the supine position was accompanied by a significant fall in the heart rate and an increase in the stroke volume in both controls (92 +/- 22 to 63 +/- 10 beats/min, and 38 +/- 9 to 62 +/- 19 ml/m2, respectively) and cirrhotic patients (101 +/- 20 to 79 +/- 13 beats/min, and 44 +/- 15 to 63 +/- 19 ml/m2, respectively). Besides, the diastolic arterial pressure fell in controls from 89 +/- 9 mmHg to 81 +/- 11 mmHg; p < 0.01, while it remained unchanged in cirrhotic patients (77 +/- 17 vs 82 +/- 13 mmHg). In the supine position, the cirrhotic patients presented tachycardia and left ventricular hyperkinesy (increased velocity of left ventricular filling and emptying). In conclusion, these results show that in compensated cirrhosis the decreased arterial tone and peripheral blood pooling are important factors of adaptive hemodynamic reaction to postural change.