Understanding Critical Lab Values

• Lab values indicate the conditions inside the body.
• Lab values are grouped by function.
• Lab values can be normal, concerning or life-threatening.

Electrolytes

• Electrolytes include Potassium (K+), Sodium (Na+), Calcium (Ca2+), and Magnesium (Mg2+).
• Electrolytes affect the heart, brain, and muscle function.

Oxygen & Acid-Base

• Oxygen & Acid-Base includes pH, CO2, O2, and HCO3.
• Oxygen & Acid-Base affects breathing and blood balance.

Blood Cells

• Blood cells include White Blood Cells (WBC), Red Blood Cells (RBC), and Platelets.
• Blood cells affect immunity and clotting.

Priority Levels of Abnormal Labs

• Level A is "No Big Deal;" requires monitoring only.
• Level B is "Concerning;" requires monitoring but is not urgent.
• Level C is "Critical;" requires quick action, patient assessment, intervention, and a call to the Healthcare Provider (HCP).
• Level D is "Deadly;" life-threatening and demands immediate action while staying with the patient.

Potassium (K+)

• Potassium is the "Heart Monitor".
• The normal range is 3.5 - 5.3 mEq/L.
• Potassium controls heart and muscle function.
• If potassium is too low (<3.5), it can cause weakness and arrhythmias.
• If potassium is too high (>5.3), it can cause irregular heartbeat and cardiac arrest.
• If potassium is low (<3.5), assess the heart, give K+, and call the HCP.
• If potassium is high (5.4-5.9), hold K+, ECG, give Kayexalate/Insulin, and call the HCP.
• If potassium is very high (≥6), the patient needs emergency treatment.
• “K+ >6 can Kill" indicates severe arrhythmias.

pH (Acid-Base Balance)

• pH is the "Organ Shutdown Risk!".
• The normal range is 7.35 - 7.45.
• If pH is too low (<7.35), it causes Acidosis (body slowing down).
• If pH is too high (>7.45), it causes Alkalosis (body speeding up).
• If pH is <7.00, it is life-threatening, requires staying with the patient, and calling the HCP.
• pH in the 6s equals possible death.

CO2 (Carbon Dioxide)

• CO2 relates to lungs and breathing.
• The normal range is 35 - 45 mmHg.
• If CO2 is too low (<35), it causes hyperventilation (breathing too fast).
• If CO2 is too high (>45), it causes breathing too slow (CO2 builds up = respiratory distress).
• If CO2 is in the 50s, encourage pursed-lip breathing and monitor.
• If CO2 is in the 60s, it causes respiratory failure and requires preparing for intubation, calling RT, and HCP.
• CO2 >60 = Call for Intubation!

PaO2 (Oxygen in the Blood)

• PaO2 helps to understand Suffocation!.
• The normal range is 78 - 100 mmHg.
• If PaO2 is too low (<60), it is an emergency because organs will fail without oxygen.
• If PaO2 is 70–77, assess breathing and give oxygen.
• If PaO2 is ≤60, it causes respiratory failure, requires staying with the patient, and preparing to intubate.
• PaO2 <60 = Not Enough Oxygen to Survive!

O2 Sat (Oxygen Saturation)

• Oxygen Saturation indicates how well the blood carries oxygen.
• The normal range is 93 - 100%.
• If O2 Sat is too low (<93%), there is not enough oxygen in the blood.
• If O2 Sat is <93%, give oxygen.
• Exceptions include anemia & dye procedures can falsely elevate O2 Sat readings.

WBC (White Blood Cells)

• WBC are “Infection Fighters!”.
• The normal range is 4,000 - 11,000.
• If WBC is too low (<4,000), it indicates a high infection risk.
• If WBC is <4,000, initiate neutropenic precautions.
• WBC <4,000 equals no immune system left!

Platelets

• Platelets indicate "Clotting vs. Bleeding Risk!".
• The normal range is 150,000 - 450,000.
• If platelets are too low (<90,000), there is an increased bleeding risk.
• If platelets are too low (<40,000), it is an emergency and indicates a spontaneous bleeding risk.
• If platelets are <90,000, monitor closely.
• If platelets are <40,000, it is a bleeding emergency and requires staying with the patient.
• 40K = Four-get clotting, indicating severe bleeding risk.

The 5 Deadly D's

• The "5 Deadly D's" are the worst labs that require immediate action".
• K+ ≥6 can cause heart stops.
• pH in the 6s can cause organ shutdown.
• CO2 in the 60s can cause respiratory failure.
• PaO2
• Platelets 40,000 can cause spontaneous hemorrhage.
• "K-PH CO2 O2 PLT" (K-PH COP).

How to Apply in NCLEX Questions

• When seeing a lab value question, check if normal, concerning (B), critical (C), or deadly (D).
• For a C-Level lab, assess, call HCP, and intervene.
• For a D-Level lab, stay with patient and call for STAT intervention.