LVN Essential Lab Values

A collection of 25 vocabulary flashcards covering high-yield adult lab values, reference ranges, and clinical significance.

Sodium (Na+)

Normal range: 135–145 mEq/L. Tells: Fluid balance and nerve function

Potassium (K+)

Normal range: 3.5–5.0 mEq/L. Tells: Heart rhythm and muscle function

Calcium (Ca2+)

Normal range: 8.5–10.5 mg/dL. Tells: Bones, muscles, and nerve function

Magnesium (Mg2+)

Normal range: 1.7–2.2 mg/dL. Tells: Muscle, nerve, and heart function

Chloride (Cl-)

Normal range: 98–106 mEq/L. Tells: Fluid and acid-base balance

Fasting Glucose

Normal range: 70–99 mg/dL. Tells: Blood sugar

BUN

Normal range: 7–20 mg/dL. Tells: Kidney function and hydration

Creatinine

Normal range: 0.6–1.3 mg/dL. Tells: Kidney function

WBC

Normal range: 4,500–11,000 /mm³. Tells: Immune system and infection

RBC — Male

Normal range: 4.7–6.1 million/mm³. Tells: Red blood cells that carry oxygen

RBC — Female

Normal range: 4.2–5.4 million/mm³. Tells: Red blood cells that carry oxygen

Hemoglobin (Hgb) — Male

Normal range: 14–18 g/dL. Tells: Oxygen-carrying protein in red blood cells

Hemoglobin (Hgb) — Female

Normal range: 12–16 g/dL. Tells: Oxygen-carrying protein in red blood cells

Hematocrit (Hct) — Male

Normal range: 42–52%. Tells: Percentage of blood made up of red blood cells

Hematocrit (Hct) — Female

Normal range: 37–47%. Tells: Percentage of blood made up of red blood cells

Platelets

Normal range: 150,000–400,000 /mm³. Tells: Helps blood clot

PT

Normal range: 11–13.5 seconds. Tells: Blood-clotting time

INR

Normal range: 0.8–1.1. Tells: Clotting measurement; commonly monitored with warfarin

aPTT

Normal range: 25–35 seconds. Tells: Clotting measurement; commonly monitored with heparin

ABG pH

Normal range: 7.35–7.45. Tells: How acidic or alkaline the blood is

PaCO2

Normal range: 35–45 mmHg. Tells: Respiratory component of acid-base balance

HCO3-

Normal range: 22–26 mEq/L. Tells: Metabolic component of acid-base balance

PaO2

Normal range: 80–100 mmHg. Tells: Oxygen pressure in arterial blood

Albumin

Normal range: 3.5–5.0 g/dL. Tells: Major blood protein; nutrition and fluid balance

Total Bilirubin

Normal range: 0.1–1.2 mg/dL. Tells: Liver function and red blood cell breakdown