Tag Archives: gastro

Acquired Liver Injury in the ICU

DEFINITIONS:

  1. liver injury – elevation in hepatic enzymes (ALT, AST, ALP, GGT)
  2. hepatic dysfunction – derangement of pathways related to synthetic or clearance function (INR and bilirubin)
  3. acute liver failure – liver injury that results in life-threatening hepatic synthetic dysfunction and brain dysfunction

 

HEPATOCELLULAR INJURY

  • injury to hepatocystes
  • elevation in serum aminotransferases
  • duration of elevation depends on severity of insult and half-life of enzyme (17h for AST and 50h for ALT)
  • most common causes
    • hypoxic hepatitis
    • congestive hepatopathy
    • septic shock
    • drug-induced
  • AST is nonspecific, also produced in skeletal muscles, heart, lung, brain, kidney, pancreas, erythrocytes, leukocytes
  • ALT is expressed mainly in the liver and normal levels exclude primary liver injury (EXCEPT in ETOH liver disease – deficiency in pyridoxal-5′-phosphate necessary for AST synthesis – low serum concentrations)

 

CHOLESTATIC INJURY

  • altered bile production, secretion or excretion
  • associated with increase in cholestatic enzymes s.a. ALP (very sensitive) and GGT, moderate or normal aminotransferases

 

 

HEPATIC DYSFUNCTION:

  • bilirubin, albumin and INR
  • causes of hyperbilirubinemia – increased production (hemolysis), decreased clearance (hepatic dysfunction) or decreased secretion (posthepatic occlusion, cholestasis)
  • major causes in the ICU:
    • insults leading to hepatocyte injury (ischemic)
    • sepsis-associated cholestasis
    • drug-induced liver injury
    • parenteral nutrition
  • serum and INR m albumin not specific for hepatic dysfunction in criticallyill

 

ELIMINATION FUNCTION

  • some dynamic tests have been developed to assess functional capacityof the liver
    • disappearance rate of teh colorant indocyanine green (ICG-PDF) to asses hepatic metabolic rate
    • hepatic vein catheterization to measure hepatic vein oxygenation as marker of splanchnic ischemia
    • measurement of liver stiffness by transient elastgraphy using Fibroscan instrument

 

MANAGEMENT OF ACUTE LIVER INJURY:

  1. Define the type of liver injury: hepatocelllular injury or cholestasis or mixed pattern
  2. perform microbiologic analysis and hepatic ultrasound
  3. maintain adequate arterial perfusion and fluid and electroiyte balances
  4. start early ABx in case of ongoing infection
  5. stop hepatotoxic medications

 

 

Causes of liver insults, definitions, and key points of intensive care unit (ICU) acquired acute liver injury, hepatic dysfunction, and acute liver failure.

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Medications Frequently Prescribed in the Intensive Care Unit that Potentially May Cause Liver Injury*

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References

Lescot, Thomas et al. “Acquired Liver Injury In The Intensive Care Unit”. Anesthesiology 117.4 (2012): 898-904.

 

 

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Hepatic Encephalopathy

JAMA Sept 2014

Polyethyene glycol 4L PO or via NGT single dose over 4 hours vs standard treatment with lactulose – (decreased time to resolution of encephalopathy from 7 to 4 days, achieved lower 24-hour HE score)

Rahimi, R., Singal, A., Cuthbert, J., & Rockey, D. (2014). Lactulose vs Polyethylene Glycol 3350-Electrolyte Solution for Treatment of Overt Hepatic Encephalopathy: The HELP Randomized Clinical Trial. JAMA Internal Medicine.

Constipation

1. Senna 17.2mg (2×8.6 tabs) PO q12, then q6
2. Bisacodyl 10mg PO q12 (max 30mg/day) or 10mg PR q12 (max 30mg/day)
3. Magnesium Citrate 1 bottle daily/q12 (be careful in people with renal failure as this has a lot of Mg)
4. Tap water enema x3
5. Lactulose 20mg q6 hrs till BM
6. Miralax 17g dissolved in 4-8 oz of beverage once
7. Fleets enema (again, not to use in renal failure) x 1 or 2
8. Relistor can be used as a last resort for opioid related constipation

DDx Liver Function Tests 

Tags: AST / ALT / Alka Phos / bilirubin

DDx of extremely high LFTs (top 3):

DDx: High Alka phos

DDx: High Bili

Work up for Abnormal Liver Function Tests

Schedule for Screening Colonoscopy

Differential Diagnosis of Abdominal Pain

Not to miss:  AAA rupture, bowel rupture/perf/ischemia, ascending cholangitis, acute appy, retroperitoneal hematoma

Abd pain quadrants