https://www.journal-of-hepatology.eu/article/S0168-8278(00)80422-5/pdf

Complications of cirrhosis. I. Portal hypertension

Ultrasonographic diagnosis of hepatic fibrosis or cirrhosis.

Genetic and environmental factors contribute to a wide inter- and intraindividual variability in drug metabolism. Among the environmental factors that may influence drug metabolism, the diet and nutritional status of the individuals are important determinants. As altered drug-metabolising enzyme activities can influence the intensity and duration of drug action, such factors should be considered in pharmacotherapy. For this reason the effects of dietary energy, protein deficiency, nutritional ingredients, special diet forms and nutrition regimens and malnutritional states must be differentiated. In various pharmacokinetic studies different model drugs metabolised either by oxidative phase I pathways [e.g. phenazone (antipyrine), aminopyrine, phenacetin, theophylline, propranolol, nifedipine] or phase II conjugation reactions [e.g. paracetamol (acetaminophen), oxazepam] were used and from the calculated pharmacokinetic data some information on the involved and affected drug-metabolising enzymes [e.g. cytochrome P450 (CYP) subspecies, glucuronosyltransferases] can be generated. It is well known that smoking, charcoal broiled food or cruciferous vegetables induce the metabolism of many xenobiotics, whereas grapefruit juice increases the oral bioavailability of the high clearance drugs nifedipine, nitrendipine or felodipine by inhibiting their presystemic (intestinal) elimination. Energy deficiency, and especially a low intake of protein, will cause a decrease of about 20 to 40% in phenazone and theophylline clearance and elimination of those drugs can be accelerated by a protein-rich diet. In the same way, protein deficiency induced by either vegetarian food or undernourishment will have the opposite pharmacokinetic consequences. On the basis of some more examples from the literature it is emphasised that the variable influence of the above factors should be taken into account in study participant selection and study design when the pharmacokinetics of a drug must be determined in healthy individuals and/or patients.

Influence of diet and nutritional status on drug metabolism.

https://aasldpubs.onlinelibrary.wiley.com/doi/pdf/10.1002/hep.1840210225

Interobserver and interequipment variability of echo-Doppler examination of the portal vein: effect of a cooperative training program.

https://aasldpubs.onlinelibrary.wiley.com/doi/pdf/10.1053/he.2000.6779

Predictive value of the variceal pressure response to continued pharmacological therapy in patients with cirrhosis and portal hypertension

https://www.gastrojournal.org/article/0016-5085(90)91097-P/pdf

Observer variability in echo-Doppler measurements of portal flow in cirrhotic patients and normal volunteers.

https://www.gastrojournal.org/article/0016-5085(92)90190-A/pdf

A Randomized study of propranolol on postprandial portal hyperemia in cirrhotic patients

Atlas of ultrasonography

To establish the prevalence and significance of Doppler-detected hepatic arteriovenous shunting (AVS) in patients with compensated cirrhosis, 115 patients (mean age 55.4 ± 12.47 SD y) were prospectively screened using real-time ultrasound with pulsed Doppler at 2.5 MHz to detect focal liver lesions and quantify AVS. Focal masses were biopsied and correlated with the US findings. All other patients had clinical follow-up and imaging for at least 12 months. AVS occurred in 28 of 115 (24.3%), and in 18 of 20 proven malignancies (90%) including 11 of 13 cases of hepatocellular carcinoma (85%). However, 9 of 28 (32%) AVS (mean Doppler shift 2.73 ± 1.51 [SD] kHz [range 0.6–5.41 kHz], n = 9) were in regions of fatty infiltration (4) or isolated (5), unassociated with malignancy. At a prevalence of 17.9% malignancy (11.3% due to hepatocellular carcinoma), specificity for malignancy increased with shunt velocity, from 76% (for mass alone), to 94.8% for mass with AVS, 96.8% for a mass with AVS of 1.75–2.4 kHz, and 100% for a mass with AVS >2.4 kHz. Doppler US is useful in characterizing liver lesions in cirrhotic patients: the majority of malignant hepatic lesions are associated with AVS and specificity for malignancy increases with shunt velocity. However, isolated AVS or AVS associated with focal fat may be detected in 7.8% of compensated cirrhotics.

Doppler ultrasound in the evaluation of cirrhotic patients: The prevalence of intrahepatic arteriovenous shunting, and implications for diagnosis of hepatocellular carcinoma

Kenneth J.W. Taylor

Papers

Observer variability in echo-Doppler measurements of portal flow in cirrhotic patients and normal volunteers.

A Randomized study of propranolol on postprandial portal hyperemia in cirrhotic patients

Atlas of ultrasonography

Doppler ultrasound in the evaluation of cirrhotic patients: The prevalence of intrahepatic arteriovenous shunting, and implications for diagnosis of hepatocellular carcinoma