Laboratory Evaluation for a 75-Year-Old with Heart Failure and Hypertension in a Skilled Nursing Facility
Order a comprehensive initial laboratory panel including complete blood count, serum electrolytes (sodium, potassium, calcium, and magnesium), blood urea nitrogen, serum creatinine, fasting blood glucose or glycohemoglobin, lipid profile, liver function tests, thyroid-stimulating hormone, and urinalysis. 1, 2
Core Laboratory Tests Required
The ACC/AHA guidelines provide explicit Class I recommendations for initial laboratory evaluation in heart failure patients, which apply regardless of care setting 1:
Essential Blood Tests
Complete blood count (CBC): Identifies anemia, which worsens heart failure symptoms and affects prognosis 2
Serum electrolytes including sodium, potassium, calcium, and magnesium: Critical for monitoring diuretic therapy effects and identifying disturbances affecting cardiac function 1, 2
Blood urea nitrogen (BUN) and serum creatinine: Essential for medication dosing (particularly ACE inhibitors, ARBs, and diuretics) and provide prognostic information 1, 2
Fasting blood glucose or glycohemoglobin (HbA1c): Necessary to manage diabetes, a major comorbidity in heart failure 1, 2
Lipid profile: Assesses cardiovascular risk and guides statin therapy 1, 2
Liver function tests: Important for detecting hepatic congestion from right heart failure and monitoring medication safety 1, 2
Thyroid-stimulating hormone (TSH): Necessary to diagnose thyroid dysfunction, which can cause or exacerbate heart failure 1, 2
Urinalysis: Screens for proteinuria and other renal abnormalities 1, 2
Critical Pitfalls to Avoid
Do not skip TSH testing—thyroid dysfunction is a reversible cause of heart failure that is frequently missed. 2, 3 This is particularly important in elderly patients where symptoms may be subtle.
Do not omit calcium and magnesium from the electrolyte panel. 1, 2 The guidelines specifically mandate these beyond standard electrolyte panels, as deficiencies affect cardiac function and arrhythmia risk.
Serial Monitoring Considerations
Recheck serum electrolytes and renal function when adjusting diuretic doses or other medications affecting these parameters 2
In a skilled nursing facility setting, establish a monitoring schedule based on medication changes and clinical stability 2
Additional Testing in Selected Circumstances
Consider these tests only when clinical suspicion exists based on history and examination 1:
Hemochromatosis screening: Reasonable in younger patients with unexplained cardiomyopathy (less relevant for this 75-year-old) 1, 2
Rheumatologic disease panels, amyloidosis workup, or pheochromocytoma screening: Only when clinical features suggest these diagnoses 1, 2
Natriuretic Peptide Testing
BNP or NT-proBNP measurement is useful when diagnostic uncertainty exists or to establish prognosis and disease severity. 2 In a skilled nursing facility with established heart failure diagnosis, this may be less critical for initial assessment but valuable for monitoring disease progression.
Practical Implementation
The comprehensive panel addresses multiple potential contributors to heart failure and guides therapeutic decisions 2. In the skilled nursing facility setting, coordinate with the facility's laboratory services to ensure all components are included, as incomplete panels missing calcium, magnesium, or TSH are common errors in practice 2, 3.