Lab studies for gastrointestinal bleeding

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🌱 來自: initial management of gastrointestinal bleeding

Lab studies for gastrointestinal bleeding🚧 施工中

Hct (may be normal in first 24 h of acute GIB before equilibration) 2–3% → 500 mL blood loss; low MCV → Fe deficient and chronic blood loss; plt, PT/INR, PTT; BUN/Cr (ratio >36 in UGIB b/c GI resorption of blood ± prerenal azotemia); LFTs

• When evaluating a patient for gastrointestinal bleeding (GIB), it is important to measure the hematocrit, which may be normal in the first 24 hours of acute GIB before equilibration.
  • A 2-3% decrease in hematocrit may indicate a loss of 500 mL of blood.
• A low mean corpuscular volume (MCV) may suggest iron deficiency and chronic blood loss.
• Other laboratory tests that may be useful include
  • measuring the platelet count,
  • prothrombin time/international normalized ratio (PT/INR), partial thromboplastin time (PTT),
  • blood urea nitrogen creatinine (BUN Cr) ratio, which may be elevated in UGIB due to
    • the resorption of blood in the gastrointestinal tract or prerenal azotemia,
  • and liver function tests (LFTs).