Langcare Lab Interpretation

FHIR Resources

• Observation -- Lab results: code (LOINC), valueQuantity, interpretation, referenceRange, effectiveDateTime, status, component
• Patient -- Age/sex for reference range selection
• Condition -- Clinical correlation with active diagnoses
• MedicationStatement -- Drug-lab interaction correlation

FHIR Query Examples

Pull Recent Labs (30 days)

fhir_search(resourceType="Observation", queryParams="patient=[patient-id]&category=laboratory&date=ge[30-days-ago]&_sort=-date&_count=200")

Pull Specific Panel (CBC)

fhir_search(resourceType="Observation", queryParams="patient=[patient-id]&code=58410-2&_sort=-date&_count=5")

Pull Prior Values for Delta Check

fhir_search(resourceType="Observation", queryParams="patient=[patient-id]&code=[loinc-code]&_sort=-date&_count=5")

Clinical Guidelines

• CAP/CLIA critical value reporting requirements
• KDIGO guidelines for renal function interpretation
• ADA standards for diabetes lab monitoring
• ACC/AHA guidelines for lipid interpretation

Interpretation Guide

• Group by panel and present in tabular format with value, reference range, and interpretation flag
• Significant delta thresholds: Hgb drop >2 g/dL, K+ change >1.0 mEq/L, Cr increase >0.3 mg/dL or >50% (AKI criteria), platelet drop >50% (HIT concern), Na change >8 mEq/L in 24h
• Abnormal patterns: elevated AST+ALT with AST/ALT >2 (alcoholic hepatitis), low MCV + low ferritin (iron deficiency), high MCV + low B12 (megaloblastic anemia), pancytopenia (bone marrow failure workup), elevated anion gap (MUDPILES differential)
• Common drug-lab interactions: metformin + elevated lactate, statins + elevated CK/ALT, ACEi + elevated K+/Cr, warfarin + INR, heparin + platelet drop (HIT)

Safety

• Never fabricate clinical data -- only report what FHIR returns
• Flag critical/abnormal values immediately
• Scope all FHIR queries to the authenticated patient
• Use standard terminology (LOINC, SNOMED CT, RxNorm, ICD-10)
• Present data in clinician-friendly format with reference ranges