Updated for 2026
NCLEX-RN nursing fundamentals: assessment, safety, and basic care
Nursing fundamentals underpin every other clinical domain. NCLEX-RN tests assessment skills, infection control, fluid and electrolyte management, wound care, mobility, health promotion, and documentation across all nursing scenarios. A strong fundamentals foundation enables clinical judgment in every other topic area.
Educational purpose: This content is for exam preparation and professional development only. It is not intended for clinical decision-making. Always follow current guidelines, institutional policies, and scope of practice.
Head-to-toe assessment and vital signs interpretation
Systematic assessment is the foundation of nursing practice. NCLEX tests the nurse's ability to collect accurate data, interpret findings, and identify abnormalities requiring escalation.
Vital signs thresholds requiring action: Temperature >38.5°C or <36°C, HR >100 or <60 bpm (context-dependent), RR >20 or <12 breaths/min, SpO2 <92% (or below patient's established baseline), systolic BP >160 or <90 mmHg, MAP <65 mmHg (perfusion concern). Pain as the fifth vital sign — assess location, quality, scale, onset, duration, radiation, and modifiers.
Neurological assessment: Glasgow Coma Scale (GCS) — Eye (1–4), Verbal (1–5), Motor (1–6). Score ≤8 = severe impairment, typically requiring airway protection. PERRLA (pupils equal, round, reactive to light, accommodate). Unequal or non-reactive pupils signal possible increased ICP or herniation — immediate escalation.
Cardiovascular-respiratory integration: Assess for clubbing (chronic hypoxia), JVD (right heart failure or volume overload), PMI displacement (cardiomegaly), S3 (heart failure), S4 (hypertension/MI), friction rub (pericarditis). Lung auscultation: crackles (fluid, atelectasis), wheezes (bronchospasm), rhonchi (secretions cleared by cough), pleural friction rub (pleuritis).
Infection control and isolation precautions
The CDC and HICPAC isolation precautions guidelines are the standard tested on NCLEX. Two tiers: Standard Precautions (for every patient) and Transmission-Based Precautions (added based on suspected pathogen).
Standard Precautions: Hand hygiene (highest-priority infection prevention measure), gloves for potential contact with body fluids/non-intact skin, gown for splashing risk, eye/face protection for splash risk, respiratory hygiene/cough etiquette, safe injection practices, and proper handling of soiled patient care equipment.
Contact Precautions: Room, gown AND gloves for every entry. Used for: MRSA, VRE, C. difficile (note: alcohol-based hand sanitiser does NOT kill C. diff spores — soap and water required), scabies, large wounds with drainage, RSV.
Droplet Precautions: Surgical mask within 3 feet; private room preferred. Used for: influenza, meningococcal meningitis, pertussis, mumps, rubella, group A Streptococcus pharyngitis, Haemophilus influenzae type b.
Airborne Precautions: N95 respirator (fit-tested), negative-pressure room with 6–12 air changes per hour, room door kept closed. Used for: TB (most tested), measles (rubeola), varicella, disseminated zoster, SARS-CoV-2 with aerosol-generating procedures. Nurse who is not immune to varicella should not care for varicella/zoster patients.
Fluid balance and electrolyte abnormalities
Fluid and electrolyte balance is fundamental to every system. NCLEX tests recognition of imbalances and appropriate nursing interventions.
Fluid volume deficit: Weight loss, dry mucous membranes, decreased skin turgor, tachycardia, hypotension, decreased urine output (<30 mL/hr), elevated specific gravity (>1.030), increased BUN:creatinine ratio. Intervention: IV fluid resuscitation (isotonic NS or LR for most presentations). Monitor urine output response.
Fluid volume excess: Weight gain, peripheral oedema, crackles, JVD, S3 gallop, hypertension, bounding pulse. Intervention: fluid restriction, diuretics, sodium restriction, daily weights, monitor I&O. Weight gain of 1 kg = approximately 1 litre of fluid retained.
Key electrolyte priorities: Hypokalemia (<3.5 mEq/L) — muscle weakness, flat T-waves, U-waves, paralytic ileus; oral or IV replacement (IV K+ never by IV push — must be diluted). Hyperkalemia (>5.0 mEq/L) — peaked T-waves, widened QRS, risk of cardiac arrest; calcium gluconate stabilises cardiac membrane, insulin+glucose drives K into cells. Hyponatremia — confusion, seizures, cerebral oedema; correct slowly (<8–10 mEq/L/day) to prevent osmotic demyelination syndrome.
Wound care, mobility, and safety
Wound healing and pressure injury prevention: Braden Scale (lower score = higher risk) assesses sensory perception, moisture, activity, mobility, nutrition, and friction/shear. Interventions for high-risk patients: reposition q2h, pressure-redistributing mattress, moisture barriers, nutrition optimisation (protein, vitamin C, zinc). Pressure injury stages: Stage 1 (intact skin, non-blanchable redness), Stage 2 (partial thickness skin loss), Stage 3 (full thickness, subcutaneous tissue visible), Stage 4 (bone/tendon/muscle visible), Unstageable (wound base obscured).
Mobility and fall prevention: Morse Fall Scale or STRATIFY. Fall prevention bundle: bed in lowest position, call light within reach, non-slip footwear, hourly rounding, medication review (sedatives, diuretics, antihypertensives increase fall risk). Post-fall: assess for injury first, then incident report, environment correction, care plan update.
Safe patient handling: Use mechanical lifts and assistive devices. Two-person assist when appropriate. Avoid dragging (shear force injures skin). Log-roll technique for spinal precautions.
Frequently asked questions
- What infection control precautions are most tested on NCLEX-RN?
- NCLEX frequently tests: Which precaution type is appropriate for a given pathogen (airborne for TB, contact for MRSA/C. diff, droplet for influenza). A key trap: C. difficile requires contact precautions AND soap-and-water hand hygiene — alcohol-based sanitisers are ineffective against spores. Varicella/zoster requires airborne + contact precautions. The nurse must know that a susceptible (non-immune) nurse should not be assigned to care for airborne-precaution patients when immune nurses are available. Room assignment also matters: negative-pressure room for airborne, private room preferred for contact/droplet.
- What is the correct nursing response when a patient's potassium is 2.8 mEq/L?
- First, assess the patient for clinical manifestations of hypokalemia: muscle weakness, leg cramps, constipation/paralytic ileus, decreased deep tendon reflexes, and cardiac changes (flat T-waves, U-waves, prolonged QT on ECG). Then notify the provider, review current medications (diuretics, corticosteroids that may cause ongoing losses), anticipate replacement orders. If IV replacement is ordered: must be diluted (never IV push), maximum infusion rate is typically 10–20 mEq/hr, administered via large peripheral vein or central line with cardiac monitoring. Oral replacement is preferred when tolerated. Also assess magnesium — hypomagnesemia impairs potassium replacement effectiveness.
Clinically reviewed by NurseNest Clinical Review Team · Last updated 2026-06-10 · For educational purposes only · Review policy