CrCl, Corrected Ca, ANC, Anion Gap

Mr. Lopez is a 68-year-old male (70 kg, 175 cm) admitted for hypertension follow-up. His SCr today is 1.1 mg/dL.
What is his estimated creatinine clearance (CrCl)?

Answer explanation

📍Answer:
CrCl = [(140 – 68) × 70] / (72 × 1.1)
= (72 × 70) / 79.2 ≈ 63.6 mL/min ✅

A 55-year-old female (SCr = 1.0 mg/dL, weight = 60 kg)
What is her CrCl?

Answer explanation

CrCl = [(140 – 55) × 60] / (72 × 1.0) × 0.85
= (85 × 60) / 72 × 0.85 = 70.8 × 0.85 = 60.2 mL/min ✅

Mr. Grant is a 65-year-old male (5'10", 105 kg, SCr 1.2).
What is his estimated CrCl using AdjBW?

Answer explanation

✅ Answer:
IBW = 73 kg → AdjBW = 85.8 kg
CrCl = [(140 – 65) × 85.8] / (72 × 1.2) = 74.4 mL/min
🧠 TBW >130% of IBW → use AdjBW

A 58-year-old patient presents with fatigue. Labs show Ca = 7.6 mg/dL and albumin = 2.4 g/dL.
What is the corrected calcium?

Answer explanation

✅ Answer:
7.6 + 0.8(4 – 2.4) = 8.88 mg/dL
🧠 Use formula when albumin <4

Ms. Tran (albumin 3.6 g/dL, Ca = 8.3 mg/dL) is starting calcium carbonate for osteopenia.
What is her corrected calcium?

Answer explanation

✅ Answer:
8.3 + 0.8(4 – 3.6) = 8.62 mg/dL
🧠 Mild hypoalbuminemia → adjust calcium

A patient with DKA presents with:
Na = 140, Cl = 100, HCO₃ = 20
What is the anion gap?

Anion Gap – normal range

A 72-year-old COPD patient’s labs:
Na = 138, Cl = 102, HCO₃ = 24
What is the anion gap?

Answer explanation

✅ Answer:
138 – 102 – 24 = 12
🧠 Upper limit of normal

WBC = 6.2 ×10³/mm³, Segs = 55%, Bands = 3%
📍What is the ANC?

___ ×10³/mm³

Answer explanation

✅ Answer:
6.2 × 0.58 = 3.6 ×10³/mm³
🧠 ANC >1500 = normal immune function

WBC = 2.1, Segs = 45%, Bands = 5%
What is the ANC?

___ ×10³/mm³

Answer explanation

✅ Answer:
2.1 × 0.50 = 1.05 ×10³/mm³ (1050 cells/mm³)
🧠 ANC <1500 = neutropenia

WBC = 1.0, Segs = 30%, Bands = 5%
What is the ANC?

___ cells/mm³

Answer explanation

✅ Answer:
1.0 × 0.35 = 350 cells/mm³
🧠 ANC <500 = severe neutropenia (high risk of infection)