Cirrhosis and Liver Failure Flashcards
Cirrhosis
Late stage of progressive hepatic fibrosis
Characterized histologically by regenerative nodules surrounded by fibrous tissue
Generally irreversible
Two types of cirrhosis
Compensated (no complications)
Decompensated (complications)
Complications of Cirrhosis
Portal hypertension- leads to variceal hemorrhage, ascites, and encephalopathy
Liver insufficiency- encephalopathy, jaundice
Etiologies of Cirrhosis
Viral Alcoholic liver disease* Autoimmune Metabolic Vascular Non-alcoholic fatty liver disease
What lab values should make you suspicious for cirrhosis?
Liver insufficiency: Low albumin ( 1.3) High bilirubin (> 1.5 mg/dL)
Portal hypertension:
Low platelet count (
What imaging findings are suspicious for cirrhosis?
Imaging studies (CT/US/MRI): Nodular liver Caudate hypertrophy Ascites Splenomegaly Venous collaterals Hepatocellular carcinoma
Model for End-Stage Liver Disease (MELD) Score
Mathematical survival model created from data on patients undergoing TIPS
MELD score estimates risk of 3-month mortality
Uses 3 laboratory values
- Serum total bilirubin
- Serum creatinine
- INR
Highest MELD score priority for transplant
Calculating MELD Scores
- 4 + 9.8 x log (INR) +
- 2 x log (Cr) +
- 8 x log (Bilirubin)
Mechanisms of Portal Hypertension and which one is predominantly responsible for portal hypertension in cirrhosis?
Portal hypertension can result from:
increase in resistance to portal flow and/or
increase in portal venous inflow (Splanchnic vasodilation (increased nitric oxide))
Increased intrahepatic resistance is the initial mechanism leading to portal hypertension
What is the site of increased resistance in cirrhosis?
Sinusoidal
What are the two main things that lead to increased resistance in cirrhosis?
Increased intrahepatic resistance in cirrhosis is not only structural (sinusoidal fibrosis and regenerative nodules) but also functional (active vasoconstriction)
In Portal Hypertension, what causes Splanchnic Vasodilation?
Increase in NO
NO in cirrhosis
In Cirrhosis, Nitric Oxide (NO) Activity is Reduced and Vasoconstrictors (VC) are Increased
What is the safest and most reproducible method to measure portal pressure?
measurement of the hepatic venous pressure gradient (HVPG)
Hepatic venous pressure gradient (HVPG)
obtained by subtracting the free hepatic venous pressure (FHVP) from the wedged hepatic venous pressure (WHVP)
HVPG = WHVP - FHVP
HVPG findings
Normal HVPG is 3-5 mmHg
HVPG is Normal in Presinusoidal Portal Hypertension
HVPG is Increased in Sinusoidal Portal Hypertension
HVPG is Increased in Post-Sinusoidal Portal Hypertension
HVPG is Normal in Post-Hepatic Portal Hypertension
Predictors of vericeal hemorrhage
Variceal size (bigger more likely to bleed)
Red signs
Child B/C (measure of disease severity)
How to reduced the Risk of Variceal Rupture
Decrease portal pressure, decreases transmural pressure and decreases wall tension
Treatment for variceal bleed
Endoscopic variceal band ligation:
Bleeding controlled in 90%
Rebleeding rate 30%
Compared with sclerotherapy: Less rebleeding Lower mortality Fewer complications Fewer treatment sessions
Transjugular Intrahepatic Portosystemic Shunt
(TIPS)
Done by interventional radiologists
Creates new communication for blood to flow through, bypassing the liver
Reduces the pressure
Good for variceal bleeding that can’t be fixed endoscopically
Done to manage refractory ascites
If on transplant list and have coagulation can use this
Complications: portal-systemic encephalopathy and liver failure.
What to do for a pt with a variceal bleed due to liver failure
Immediately give a vasoconstrictors (e.g., octreotide*)
and call GI for endoscopy
Octreotide
A vasoconstrictor that decreases splanchnic flow, slightly increases intraheptaic resistance and decreases portal pressure
What is the Most Common Cause of Ascites?
cirrhosis (80%)
Mechanism of ascites development
Result from an Increase in Nitric Oxide, leading to vasodialtion, decreased systemic vascular resistance, activation of RAAS system, Na2+ and H2O retention and ascites
Natural History of Ascites
Portal Hypertension- No Ascites
Uncomplicated Ascites
Refractory Ascites
Hepatorenal Syndrome
What is the Most Sensitive Method to Detect Ascites?
Ultrasound
Initial Workup of Ascites
Diagnostic Paracentesis:
PMN count
Culture
Protien/albumin
Serum-Ascites Albumin Gradient (SAAG) calculation
serum albumin minus ascites albumin (should be drawn at the same time)
SAAG
correlates with sinusoidal pressure
>1.1 SAAG
The cutoffs for SAAG and ascites protein levels are 1.1 g/dL and 2.5 g/dL respectively. Cirrhotic ascites is typically high SAAG and low protein; cardiac ascites is high SAAG and high protein; and ascites secondary to peritoneal malignancy is typically low SAAG and high protein.
Therapies for ascites
Salt restriction and Diuretics
Large volume paracentesis
TIPS (if refractory and low MELD score)
Refractory Ascites
Occurs in ~10% of cirrhotic patients
Diuretic-intractable ascites (80%): Therapeutic doses of diuretics cannot be achieved because of diuretic-induced complications
Diuretic-resistant ascites (20%): No response to maximal diuretic therapy (400 mg spironolactone + 160 mg furosemide/day)
Hepatorenal Syndrome
Renal failure in patients with cirrhosis, advanced liver failure and severe sinusoidal portal hypertension
Absence of significant histological changes in the kidney (“functional” renal failure)
Marked arteriolar vasodilation in the extra-renal circulation
Marked renal vasoconstriction leading to reduced glomerular filtration rate
Besides renal failure, patients with HRS have sodium and water retention
Ascites is universal in patients with HRS.
If ascites is absent, renal failure is more likely due to other causes
Hyponatremia is almost universal in HRS.
If serum sodium is normal, diagnosis of HRS is unlikely
Types of Hepatorenal Syndrome
Type 1
Rapidly progressive renal failure (2 weeks)
Doubling of creatinine to >2.5 or halving of creatinine clearance (CrCl) to 1.5 mg/dL or CrCl
Major Criteria in the Diagnosis of Hepatorenal Syndrome
Advanced hepatic failure and portal hypertension
Creatinine > 1.5 mg/dL or creatinine clearance
Management of Hepatorenal Syndrome
Proven efficacy:
Liver transplantation
Under investigation: Vasoconstrictor + albumin Transjugular intrahepatic portosystemic shunt (TIPS) Vasoconstrictor (Terlipressin) Extracorporeal albumin dialysis (ECAD)
Ineffective:
Renal vasodilators (prostaglandin, dopamine)
Hemodialysis
Spontaneous bacterial peritonitis and hepatorenal syndrome
Spontaneous Bacterial Peritonitis (SBP) Complicates Ascites and Can Lead to Renal Dysfunction
What is the Most Common Infection in Cirrhotic Patients? and what’s the mechanism?
Spontaneous Bacterial Peritonitis (SBP)
Bacterial translocation-migration of viable microorganisms from the intestinal lumen to mesenteric lymph nodes and other extraintestinal organs and sites
Mechanisms of Bacterial Translocation
- Intestinal Bacterial Overgrowth- Dysmotility Delayed transit time
- Intestinal Permeability- Mucosal Hypoxia, Acidosis
ATP depletion, NO, LPS, TNF - Impaired Immunity- Impaired chemotaxis, migration, phagocytic function, complement deficiency, etc.
Microorganisms in SBP and treatment
Gram negative bacilli (72%)
cephalosporins
NO aminoglycosides
Recurrence of Spontaneous Bacterial Peritonitis
Common!!
70% chance of developing another episode within the first year
So prophylaxis
Hepatic Encephalopathy
Neuropsychiatric complication of cirrhosis
Ammonia is the culprit
Results of both: Portosystemic shunt (spontaneous, surgical or radiographic) and Chronic liver failure
Failure to metabolize neurotoxic substances
Hyperammonemia results in glutamine accumulation
Alterations of astrocyte morphology and function (Alzheimer type II astrocytosis)
Astrocytes only cells in brain that can metabolize ammonia
How to diagnose hepatic encephalopathy
Clinical diagnosis
Clinical findings and history important Ammonia levels are unreliable Ammonia has poor correlation with diagnosis Measurement of ammonia not necessary Number connection test Slow dominant rhythm on EEG
Treatment for encephalopathy
Identify and treat precipitating factor: Infection GI hemorrhage Prerenal azotemia Sedatives Constipation
lactulose or antibiotics (kill bacteria that produce ammonia)
Adjustment in dietary protein (short-term if at all)
Hepatic Encephalopathy Precipitants
Excess protein TIPS Infections Sedatives/hypnotics Diuretics GI bleeding