GASTROENTEROLOGY

 

GI Bleeding

Hx:

Upper GIB hematemesis (bright red or coffee grounds), melena or hematochezia (BRBPR).

Etiology: peptic and esophageal ulcers (drugs/infectious/ Z-E/GERD), portal HTN, vascular lesions, trauma, tumors.

Lower GIB presents with hematochezia or melena.

Etiology: diverticulosis, vascular lesions, infection, ischemia, IBD, radiation, tumors.

Dx: if active bleed (1cc/min) tagged RBC scan in nuclear medicine may be useful – if positive halsted surgery for GI resection vs CVDL for embolization

Rx: two 16-18 gauge peripheral IVs, NG lavage until clear, T&S (ABO Rh), NPO, q6h Hcts, IVF  correct coagulopathies (FFP, plts), IV Protonix 8mg/hr, GI consult for endoscopy, Halsted surgery consult for potential resection.

 

Acute Hepatitis

Etiology: infection (HAV, HBV, HCV, CMV, HSV, toxoplasmosis, VZV), metabolic (hemochromatosis, Wilson’s disease), cholestasis (choledokolithiasis, etc.), immune (autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis), alcoholic hepatitis (AST:ALT > 2:1), non-alcoholic steatohepatitis, medications (acetaminophen), toxins (carbon tetrachloride, Amanita phalloides), vascular (shock liver, Budd-Chiari, veno-occlusive disease – as in chemotherapy/BMT), Reyes syndrome, and malignancy.

Dx: serum volatiles, ammonia, acetaminophen level, PT, PTT, direct bilirubin, viral serologies for hepatitities, CMV, HSV, EBV & monospot, VZV, ferritin & iron studies (usually elevated in acute hepatitis), ceruloplasmin, ANA, anti-smooth muscle / anti-mitochondrial, anti-LKM (liver/kidney microsomal).  If negative obtain hemochromatosis gene mutation (C282Y, H63D) (path 3 form code 8872), 24 hr urine copper, CEA, AFP, ophthalmology consult to assess for Kayser-Fleischer rings, liver biopsy.

Rx: lactulose for encephalopathy.

Alcoholic hepatitis: Maddrey discriminant factor [4.6 x (PT – control PT) + total bilirubin (mg/dL)] if > 32 risk of death is high (>50%) treat with steroids & pentoxifylline 400mg po tid x 4wks.

[J Gastro & Hep (2002) 17:448 – 55.]

 

Liver Transplant

MELD Score (Model for End-Stage Liver Disease): (United Network for Organ Sharing version)

      http://www.mayoclinic.org/gi-rst/mayomodel6.html

Predicts 1 yr survival with liver failure & survival post-transplant. [Hepatology (2001) 33: 464-70]

Liver transplant w/u: NH4, HBsAg, HbcAg, HCV, HCV-pcr, CMV IgG, EBV, serology, HSV serology, VZV IgG, RPR, HIV, ABO typing, CEA, AFP, PSA (if male), 3-D CT of liver, PFTs (flow-volume & DLCO), CXR, dobutamine stress echo + cardiology consult (if > 45y/o or has DM), vaccinate: HBV, HAV, pneumovax.

 

Acute Pancreatitis

Etiology:  alcohol or gallstones (account for 60-75% of cases), idiopathic, hypertriglyceridemia, post-ERCP, hypercalcemia, drugs (including ddI, pentamidine, Lasix, 5-ASA, azathioprine, sulfonamides), infections (CMV, VZV, HSV, Hepatitis B, Mycoplasma, Legionella, Toxoplasma), abdominal trauma, pancreas divisum, pregnancy.

Hx:  Acute onset of abd pain, upper abdomen/epigastric with radiation to the back (sometimes, relief with bending forward), nausea/vomiting, abdominal distention.  Look for Grey-Turner’s & Cullen’s signs.

Ranson’s criteria (predictors of bad outcome): On admission:  age > 55yrs, WBC >16K, Glucose > 200, LDH > 350, AST > 250.  During initial 48hrs:  >10% decrease in Hct, > 5mg/dl (1.8mmol/liter), Ca < 8, PaO2 < 60, base deficit > 4mmol/liter, fluid sequestration > 6 liters

Dx:  Amylase, lipase.  Consider lipid panel and infectious work-up can be ordered.  CRP as possible predictor of severity and outcome of acute pancreatitis. Abdominal CT with contrast (r/o abscess, pseudocyst, necrosis), AXR (r/o perforation, obstruction), RUQ U/S, especially for first-time pancreatitis

Rx: NPO, IVF, pain control (may require PCA).  NGT indicated for patients with severe ileus or vomiting.  Patients with gallstones may benefit from ERCP or surgical cholecystectomy.  Abx indicated for evidence of pancreatic necrosis/sepsis (meropenem).

 

Spontaneous Bacterial Peritonitis

Defn: ascitic infection without evidence of surgically treatable source.

Ascites plus one or more of the following: Temp> 100 F, abdominal pain, delta MS, ascitic PMNs > 250/mm3

 

Dx: Paracentesis -- Give 10g albumin per liter of ascitic fluid removed before or during procedure. Send fluid for CBC/diff, albumin (send blood CMP at same time), protein (ascitic fluid total protein—AFTP), culture (use blood culture aerobic and anaerobic bottles for greater yield, changing skin needles before inoculating culture bottles), glucose, LDH, Gram stain, cytology.

SAAG (serum albumin – ascitic albumin) > 1.1 (portal-HTN related)

< 1.1 (non-portal HTN related).

CHF (cardiac ascites): SAAG > 1.1, AFTP > 2.5 g/dL

SBP: SAAG < 1.1, AFTP < 2.5 g/dL

 

Rx: Rule-out secondary (surgically treatable) causes (eg, ruptured viscus, abscess, etc): Abdominal CT w/ IV and PO contrast, high LDH, polymicrobial infection, ascitic protein > 1g/dL, glucose < 50 g/dL suggest secondary peritonitisàsurgical consult STAT!  2) Gentle diuresis w/ po spironolactone/lasix (see above) to concentrate peritoneal fluid proteins and increase opsonization. 3) Cefotaxime 2 g q8hrs x 5-10 days (add metronidazole if evidence of secondary SBP) 4) Albumin IV 1.5 g/kg at diagnosis, followed by 1g/kg at day 3.

5) Prophylaxis in pts w/ ascitic fluid protein < 1g/dL, variceal hemorrhage, or prior episodes of SBP—Norfloxacin 400 mg po qd while in hospital. Bactrim DS  1 qd on discharge home.

[Aliment Pharmacol Ther 2001; 15: 1851-1859.]  

 

Cirrhosis Ascites: (caused by portal hypertenson > 12 mmHg)

Rx: Bedrest; Na restriction to 2g/d; fluid restriction (if hyponatremic); avoid NSAIDs; gentle diuresis w/ spironolactone 100 mg po qd and Lasix 40 mg po qd (avoid hypokalemia by keeping this ratio constant—increase to a maximum of  spironolactone 400 and Lasix 160 po qd. Restrict fluid loss to maximum of 500-800 mls/day to avoid intravascular depletion and azotemia—fluid movement out of peritoneal cavity restricted by capillaries to ~500 mls/day); paracentesis if new-onset ascites, symptomatic (tense abdomen, respiratory compromise, hypotensive) s/sx of SBP present, or if ascites is diuretic resistant (after titrating up spironolactone/lasix doses).