NCLEX Lab Values Flashcards
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How to run these cards
Work in one direction first: read the front, say the answer out loud, then open the card. Saying it out loud is not a gimmick — recognising an answer and producing one are different skills, and the exam only rewards the second. Anything you get wrong goes into a pile you repeat at the end of the session, then again the next day.
Do not run a deck front-to-back every time. Order is itself a memory cue, so a deck you always run in sequence will feel mastered and then fall apart inside a mixed practice test.
Lab Values
Ranges, critical values and what each abnormal number predicts.
25 cards — 11 easy, 14 medium.
Normal serum potassium?
3.5 to 5.0 mEq/L
The narrowest safe range of the everyday electrolytes and the fastest route to arrest.
ECG change of hyperkalaemia?
Peaked T waves, then a widening QRS.
Treat with calcium gluconate to protect the heart, then insulin and dextrose to shift.
ECG change of hypokalaemia?
Flattened T waves and prominent U waves.
Low potassium also potentiates digoxin toxicity.
Normal serum sodium?
135 to 145 mEq/L
Both high and low sodium present neurologically. Correct slowly in either direction.
Normal arterial pH, PaCO2 and bicarbonate?
pH 7.35 to 7.45, PaCO2 35 to 45 mmHg, HCO3 22 to 26 mEq/L
ROME: Respiratory Opposite, Metabolic Equal.
Therapeutic INR on warfarin?
Generally 2 to 3, or 2.5 to 3.5 with a mechanical valve.
Baseline INR without warfarin is 0.8 to 1.1.
Which test monitors heparin?
aPTT, therapeutic at 1.5 to 2.5 times the control value.
Also follow the platelet count for heparin-induced thrombocytopenia.
Normal platelet count, and the bleeding thresholds?
150,000 to 400,000/mm3. Bleeding precautions under 50,000; spontaneous bleeding risk under 20,000.
Soft toothbrush, electric razor, no rectal temperatures or suppositories.
Absolute neutrophil count that means severe risk?
Under 500/mm3
Fever in a neutropenic client is an emergency, often the only sign of infection.
Most specific marker of myocardial injury?
Troponin I
It rises within 3 to 4 hours and stays elevated for days.
What does an elevated BNP suggest?
Volume overload, usually a cardiac cause of dyspnoea.
Normal is under 100 pg/mL. It helps separate cardiac from pulmonary breathlessness.
Therapeutic digoxin level?
0.5 to 2.0 ng/mL
Toxicity brings nausea, anorexia, halo vision and dysrhythmias.
Normal BUN and creatinine?
BUN 10 to 20 mg/dL, creatinine 0.6 to 1.2 mg/dL
A high BUN with normal creatinine usually means dehydration, not kidney damage.
When is a vancomycin trough drawn?
Immediately before the next scheduled dose.
Target trough is generally 10 to 20 mcg/mL. Monitor renal function and hearing.
Normal haemoglobin ranges?
Male 14 to 18 g/dL, female 12 to 16 g/dL
Transfusion is generally considered around 7 g/dL in a stable adult.
Normal fasting glucose and HbA1c target in diabetes?
Fasting 70 to 100 mg/dL; HbA1c target usually under 7 percent.
HbA1c reflects roughly three months of glycaemic control.
Which enzymes rise in pancreatitis?
Amylase early, lipase more specifically and for longer.
Pain is epigastric, radiating to the back, relieved by leaning forward.
What does a rising ammonia level indicate?
Hepatic encephalopathy
Lactulose lowers it; the goal is two to three soft stools a day.
Normal urine specific gravity, and what a high value means?
1.005 to 1.030. High means concentrated: dehydration or SIADH.
A low value means dilute urine: overload or diabetes insipidus.
Normal serum calcium, and the signs of a low level?
9.0 to 10.5 mg/dL. Low causes Chvostek and Trousseau signs, tetany and tingling.
Refractory hypocalcaemia often needs magnesium replaced first.
Magnesium infusion hold parameters in obstetrics?
Absent deep tendon reflexes, respirations under 12, or urine output under 30 mL/hour.
Stop the infusion first, then give calcium gluconate.
Oxygen saturation target for a chronic CO2 retainer?
88 to 92 percent
Driving the saturation higher can worsen carbon dioxide retention.
Minimum acceptable adult urine output?
30 mL per hour
Below this, report it. It is an early marker of poor perfusion.
Therapeutic phenytoin level, and toxicity signs?
10 to 20 mcg/mL. Toxicity causes nystagmus and ataxia.
Gingival hyperplasia is a chronic effect requiring meticulous oral care.
How much fluid does a 1 kilogram weight change represent?
About 1 litre
Daily weight is the most reliable measure of fluid status.
What these cards cover
These 25 cards sit across 3 topics in the test plan. If a whole topic keeps coming back wrong, the problem is the underlying content rather than the recall — go and read that topic before you run the deck again.
| Topic | Focus | Cards | Client need category |
|---|---|---|---|
| Interpreting Laboratory Values | Which number, which action | 23 | Reduction of Risk Potential |
| Acid-Base Balance | Reading a blood gas in four steps | 1 | Physiological Adaptation |
| Fluid and Electrolyte Balance | Volume status and the six key electrolytes | 1 | Physiological Adaptation |
Printable answer key
The same 25 cards laid flat, for revision on paper or a last pass the night before. Cover the right-hand columns with a sheet and work down.
| Prompt | Answer | Why it matters |
|---|---|---|
| Normal serum potassium? | 3.5 to 5.0 mEq/L | The narrowest safe range of the everyday electrolytes and the fastest route to arrest. |
| ECG change of hyperkalaemia? | Peaked T waves, then a widening QRS. | Treat with calcium gluconate to protect the heart, then insulin and dextrose to shift. |
| ECG change of hypokalaemia? | Flattened T waves and prominent U waves. | Low potassium also potentiates digoxin toxicity. |
| Normal serum sodium? | 135 to 145 mEq/L | Both high and low sodium present neurologically. Correct slowly in either direction. |
| Normal arterial pH, PaCO2 and bicarbonate? | pH 7.35 to 7.45, PaCO2 35 to 45 mmHg, HCO3 22 to 26 mEq/L | ROME: Respiratory Opposite, Metabolic Equal. |
| Therapeutic INR on warfarin? | Generally 2 to 3, or 2.5 to 3.5 with a mechanical valve. | Baseline INR without warfarin is 0.8 to 1.1. |
| Which test monitors heparin? | aPTT, therapeutic at 1.5 to 2.5 times the control value. | Also follow the platelet count for heparin-induced thrombocytopenia. |
| Normal platelet count, and the bleeding thresholds? | 150,000 to 400,000/mm3. Bleeding precautions under 50,000; spontaneous bleeding risk under 20,000. | Soft toothbrush, electric razor, no rectal temperatures or suppositories. |
| Absolute neutrophil count that means severe risk? | Under 500/mm3 | Fever in a neutropenic client is an emergency, often the only sign of infection. |
| Most specific marker of myocardial injury? | Troponin I | It rises within 3 to 4 hours and stays elevated for days. |
| What does an elevated BNP suggest? | Volume overload, usually a cardiac cause of dyspnoea. | Normal is under 100 pg/mL. It helps separate cardiac from pulmonary breathlessness. |
| Therapeutic digoxin level? | 0.5 to 2.0 ng/mL | Toxicity brings nausea, anorexia, halo vision and dysrhythmias. |
| Normal BUN and creatinine? | BUN 10 to 20 mg/dL, creatinine 0.6 to 1.2 mg/dL | A high BUN with normal creatinine usually means dehydration, not kidney damage. |
| When is a vancomycin trough drawn? | Immediately before the next scheduled dose. | Target trough is generally 10 to 20 mcg/mL. Monitor renal function and hearing. |
| Normal haemoglobin ranges? | Male 14 to 18 g/dL, female 12 to 16 g/dL | Transfusion is generally considered around 7 g/dL in a stable adult. |
| Normal fasting glucose and HbA1c target in diabetes? | Fasting 70 to 100 mg/dL; HbA1c target usually under 7 percent. | HbA1c reflects roughly three months of glycaemic control. |
| Which enzymes rise in pancreatitis? | Amylase early, lipase more specifically and for longer. | Pain is epigastric, radiating to the back, relieved by leaning forward. |
| What does a rising ammonia level indicate? | Hepatic encephalopathy | Lactulose lowers it; the goal is two to three soft stools a day. |
| Normal urine specific gravity, and what a high value means? | 1.005 to 1.030. High means concentrated: dehydration or SIADH. | A low value means dilute urine: overload or diabetes insipidus. |
| Normal serum calcium, and the signs of a low level? | 9.0 to 10.5 mg/dL. Low causes Chvostek and Trousseau signs, tetany and tingling. | Refractory hypocalcaemia often needs magnesium replaced first. |
| Magnesium infusion hold parameters in obstetrics? | Absent deep tendon reflexes, respirations under 12, or urine output under 30 mL/hour. | Stop the infusion first, then give calcium gluconate. |
| Oxygen saturation target for a chronic CO2 retainer? | 88 to 92 percent | Driving the saturation higher can worsen carbon dioxide retention. |
| Minimum acceptable adult urine output? | 30 mL per hour | Below this, report it. It is an early marker of poor perfusion. |
| Therapeutic phenytoin level, and toxicity signs? | 10 to 20 mcg/mL. Toxicity causes nystagmus and ataxia. | Gingival hyperplasia is a chronic effect requiring meticulous oral care. |
| How much fluid does a 1 kilogram weight change represent? | About 1 litre | Daily weight is the most reliable measure of fluid status. |
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