1 Foundations of Laboratory Interpretation and Nursing Response

Interpret results in context

Laboratory results are clues about a patient’s condition, not diagnoses in isolation. Interpret each result alongside symptoms, baseline, treatment, and the urgency of any change.

Start by confirming the patient, test, specimen, units, collection time, and the reference interval printed by that laboratory. Ranges can differ by laboratory, method, age, and other factors. Do not assume that a flagged result proves disease or compare it with an unrelated range.

Compare the result with the patient’s baseline and trend: determine whether it is stable, improving, or changing rapidly. When possible, compare results from the same laboratory, and account for timing, treatment, and fluid shifts. A substantial change from baseline may matter even when a result remains within the reference interval.

Consider why testing was done, the patient’s history and current diagnosis, symptoms, medications, recent procedures, and relevant age- or pregnancy-related factors. A result expected in one clinical context may be concerning in another.

Assess the patient, not just the number. Review vital signs, mental status, symptoms, physical findings, and available related tests. A reassuring result does not rule out deterioration, and a mildly abnormal result may be important when the patient is symptomatic.

Recognize urgency and prioritize

A critical result is one the organization defines as requiring urgent communication because it may represent a high-risk or life-threatening state. Critical thresholds and reporting procedures are facility-specific. Follow current policy and the patient’s individualized plan where applicable; do not substitute a textbook range or personal judgment for the approved process.

Prioritize immediate bedside assessment and response when a result is critical, rapidly worsening, or accompanied by signs of instability. For example, a reported critical potassium result warrants prompt assessment for symptoms and cardiac instability and immediate escalation under policy. A rapidly falling hemoglobin with new hypotension or bleeding, and a low glucose result with altered responsiveness, also call for urgent assessment and action. These examples illustrate priorities, not universal numeric cutoffs or standalone diagnoses.

Respond and communicate safely

Assess promptly

Check airway, breathing, circulation, mental status, symptoms, vital signs, and relevant focused findings. If the patient appears unstable, activate the emergency or rapid-response process according to policy. Do not wait for a repeat test or routine callback.

Verify while care continues

Check patient and specimen identifiers, collection time, units, and any laboratory comment on the result or specimen, such as hemolysis. Contact the laboratory or request repeat testing when indicated by policy or a clinician’s direction. A possible artifact should be investigated, but assessment and escalation for an urgent concern must continue in parallel.

Communicate and escalate

Notify the appropriate clinician or designated recipient promptly through the required pathway. Use SBAR to organize the message:

• Situation: the result and immediate concern.

• Background: relevant history and trend.

• Assessment: current symptoms and findings.

• Recommendation/Request: the response needed.

If the response is delayed or does not address an unresolved safety concern, escalate through the chain of command.

Follow through and document

Use read-back or check-back when required. Record the result, time received, assessment, people notified, instructions, actions, repeat testing if ordered, and the patient’s response. Continue reassessment until the concern is addressed, and hand off outstanding results or actions.

Maintain safe practice

Keep nursing actions within scope, orders, and facility protocols. Do not independently initiate treatment outside those parameters; seek clarification when an order or response is unclear.

Use the report’s own reference interval, the patient’s baseline and trend, and clinical context to interpret results. Treat critical results, rapid changes, and concerning symptoms as priorities for assessment and timely escalation. Verify and communicate carefully, but never let result-checking delay emergency care.