8.1 Vital Signs Assessment

Vital Signs as Early Warning Data

Vital signs are the foundation of patient assessment and the first measurable sign of decline. Reduction of Risk Potential accounts for 9-15% of the NCLEX-PN under Physiological Integrity, and vital-sign items routinely ask you to identify the abnormal value, decide whether it is expected or reportable, and choose the correct LPN/VN action — which is usually to report to the registered nurse (RN), not to independently change the plan of care.

Normal Adult Ranges and Report Thresholds

Temperature Routes

The NCLEX expects you to match route to patient and to know that rectal readings run about 1°F higher and axillary about 1°F lower than oral.

Hypothermia below 95°F (35°C) and hyperpyrexia above 105.8°F (41°C) are emergencies.

Pulse and the Apical Rule

Grade pulse quality 0 (absent) to 3+ (bounding); 2+ is normal. A pulse deficit — a faster apical than radial rate — suggests ineffective beats, as in atrial fibrillation, and requires two nurses counting simultaneously for one minute. Worked example: before a scheduled dose of digoxin, you count an apical rate of 54 bpm for a full minute. Because the rate is under 60, you hold the dose and notify the RN — giving it could worsen bradycardia and signal digoxin toxicity.

Blood Pressure Technique and Categories

Seat the patient quietly 5 minutes, support the arm at heart level, and use a cuff bladder covering ~80% of the arm — a too-small cuff falsely raises the reading. Inflate 30 mmHg above the palpated systolic, deflate 2-3 mmHg/second; the first Korotkoff sound is systolic, the last is diastolic.

Orthostatic (postural) hypotension is a drop of ≥ 20 mmHg systolic or ≥ 10 mmHg diastolic within 1-3 minutes of standing — measure lying, then sitting, then standing. It is common with diuretics, antihypertensives, dehydration, and aging, and it predicts fall risk.

Respiratory Patterns

Count respirations for a full minute when irregular, and observe rate, depth, rhythm, and effort.

Pulse Oximetry Traps

SpO2 below 90% is critical. Falsely high readings occur with carbon monoxide poisoning; falsely unreliable readings occur with motion, cold or poorly perfused extremities, dark nail polish, and severe anemia (the oxygen carried may be adequate as a percentage even when total content is low). A common NCLEX trap is choosing "reposition the probe" when the patient also shows dyspnea and cyanosis — in that case, the SpO2 is real: apply oxygen and notify the RN first.

Age-Related and Special Considerations

Vital-sign norms shift with age, and the NCLEX-PN tests these endpoints. Infants normally run a faster pulse (100-160 bpm) and respiratory rate (30-60/min) and a lower blood pressure; count an infant's apical pulse and respirations for a full minute because both are irregular. Older adults often have a widened pulse pressure, are more prone to orthostatic drops, and may mount only a blunted fever — so a temperature of 99.5°F in an elderly resident can still signal serious infection. Always interpret a single reading against the patient's own baseline and trend, not just the textbook range.

Putting It Together: Priority Reasoning

When several values are abnormal, the NCLEX wants you to triage by airway, breathing, circulation (ABC). A falling SpO2 with rising respiratory rate outranks a mild fever; new bradycardia in a patient on digoxin outranks a stable blood pressure. The LPN/VN reassesses to confirm a borderline reading (recount the apical pulse, recheck the cuff size) but never delays reporting a clearly critical value to chase a repeat measurement. Document the reading, the patient's symptoms, the time, and the notification — and follow agency policy for rapid-response activation when deterioration is rapid.