Hemostasis Today
NewsFeed
Headlines Hematology Health Medicine VTE ASH Plasma Donation
Hossam Qassem: The Stepwise Investigation Framework for ICU Hemoglobin Drop
Hossam Qassem/LinkedIn
Mar 24, 2026, 16:57

Hossam Qassem: The Stepwise Investigation Framework for ICU Hemoglobin Drop

Hossam Qassem, ICU Clinical pharmacist at Mabaret AlAsafra Group for Medical Services, shared a post on LinkedIn:

“Hgb dropped 2 g/dL overnight. No visible bleeding.
No bloody output.

Do you transfuse — or do you find out Why

Day 140 – ICU Hemoglobin Drop: The Stepwise Investigation Framework

Why this matters

Unexplained Hgb drop is a diagnostic emergency, not a transfusion trigger.

Missing the cause means missing hemolysis, occult hemorrhage, or iatrogenic loss — all with distinct, time-sensitive workups.

Transfusing without a diagnosis delays correction. And adds harm.

The dilemma

Treat the number OR investigate the cause?

Pattern interrupt: A patient bleeding into a retroperitoneal hematoma or lysing cells in a circuit does not benefit from 2 units of pRBCs without a diagnosis.

The Hgb drop is the symptom.
The investigation is the intervention.

When to investigate urgently

Hgb drop is higher than 1.5 g/dL within 24h indicates the need for mandatory workup
Drop despite recent transfusion suggests active loss OR hemolysis
High HR with Low MAP and falling Hgb should be considered hemorrhage until proven otherwise
Easy to miss: Hgb falling slowly over 3-5 days may reflect cumulative phlebotomy loss or dilution — not ‘just the ICU’

The stepwise investigation

STEP 1 — Quantify (within 1 hour)

  • Compare to TRUE baseline — not post-resuscitation Hgb
  • Reticulocyte count with Reticulocyte Production Index (RPI)
    RPI less than 2 bone marrow not responding (hypoproliferative)
    RPI greater than 3 active loss or hemolysis (marrow compensating)
  • Estimated blood loss is equal to [AHgb divided by Baseline Hgb] multiplied by 70 mL/kg

STEP 2 – Rule Out Hemorrhage (1-2 hours)

Visible sources:

  • All drain outputs, wound sites, line insertion points
  • NG aspirate if upper GI suspected
  • Stool guaiac / rectal exam

Occult hemorrhage:

  • POCUS shows free fluid in Morrison’s pouch, splenorenal space
  • CT abdomen/pelvis with contrast shows retroperitoneal, hepatic, splenic hematoma
  • BUN:Cr greater than 20:1 suggests upper Gi bleed until ruled out

STEP 3 — Rule Out Hemolysis (2-4 hours)

Per ASH 2022:

  • High LDH  and high indirect bilirubin and haptoglobin less than 25 mg/dL indicates hemolysis confirmed
  • Peripheral smear showing schistocytes indicates MAHA (TTP / HUS /DIC)

Direct Coombs (DAT):

  • Positive means immune-mediated (AIHA, drug-induced, transfusion reaction)
  • Negative means non-immune (mechanical, oxidative, circuit-related)

Review MAR: cephalosporins, piperacillin, NSAIDs added in last 72h?
Post-transfusion drop requires ruling out acute hemolytic transfusion reaction first

STEP 4 — Rule Out Dilution + latrogenic Loss (same day)

  • Fluid balance greater than 3L positive suggests dilutional component likely
  • Cumulative phlebotomy greater than 150 mL over 72h is clinically significant
    Switch to pediatric tubes (reduces draw volume 30-50%)
  • MCV low prompts ferritin, TIBC and serum iron for iron deficiency
  • MCV high prompts B12 and folate evaluation
  • ICU stay longer than 7 days with no other cause suggests anemia of critical illness (diagnosis of exclusion)

Pearl:
‘The Hgb tells you something is wrong.
The smear and the retic tell you what to do about it.'”

Hossam Qassem

Stay updated with Hemostasis Today.

bleeding bleeding disorders Blood Blood Smear haemophilia Health Hematology Hemoglobin hemolysis hemorrhage Hemostasis Hemostasis News Hemostasis Today Hossam Qassem ICU Medicine Transfusion Medicine
NewsFeed