Burch-Wartofsky Point Scale (BWPS) for Thyrotoxicosis
Estimates the likelihood of thyroid storm in patients with thyrotoxicosis
Calculator
Why use it
Thyroid storm is a clinical diagnosis with no pathognomonic laboratory findings — thyroid hormone levels may overlap with uncomplicated thyrotoxicosis. The BWPS provides an objective, quantitative framework for diagnosis and triage. A score ≥ 45 warrants aggressive treatment even while awaiting confirmatory thyroid function tests, as delays increase mortality.
About
The Burch-Wartofsky Point Scale (BWPS) is the most widely used clinical scoring system for estimating the likelihood of thyroid storm (thyrotoxic crisis) in patients with suspected thyrotoxicosis. Thyroid storm is a life-threatening emergency with a mortality rate of 10–30% even with treatment, and early recognition is critical. The BWPS assigns points across six clinical domains: thermoregulatory dysfunction (temperature), cardiovascular dysfunction (tachycardia, congestive heart failure, atrial fibrillation), CNS effects, GI-hepatic dysfunction, and the presence of a precipitating event. The scale was developed to standardize the highly variable clinical presentation of thyroid storm.
When to use
- Patients with known or suspected hyperthyroidism presenting with acute illness, fever, or multisystem involvement
- Unexplained extreme tachycardia, hyperpyrexia, or altered mental status in a patient with thyroid disease or goiter
- Post-surgical or post-radioiodine therapy with acute decompensation
- ICU patients with unexplained hypermetabolic state
- Emergency department evaluation of suspected thyroid storm
Formula
Pearls & pitfalls
- Thyroid storm has NO single definitive lab test — BWPS is used clinically to initiate treatment before lab confirmation.
- PTU is preferred over methimazole in thyroid storm because it also blocks peripheral T4→T3 conversion.
- Iodine (Lugol's solution or SSKI) must be given ≥1 hour AFTER PTU/methimazole to prevent the iodine from being used for new hormone synthesis (Wolff-Chaikoff effect).
- Aspirin is CONTRAINDICATED in thyroid storm — it displaces thyroid hormones from binding proteins, worsening free hormone levels.
- Common precipitants: infection (most common), surgery, radioiodine therapy, iodine load (contrast, amiodarone), trauma, labor, medication non-compliance.
- Corticosteroids (hydrocortisone 100 mg IV q8h) serve two purposes: adrenal protection (stress state) and reduction of T4→T3 conversion.
- Plasmapheresis or cholestyramine are rescue options for refractory thyroid storm not responding to standard treatment.
Next steps
BWPS < 25: Thyroid storm unlikely — evaluate and treat underlying thyrotoxicosis per guidelines (antithyroid drugs, beta-blockers). BWPS 25–44: Impending thyroid storm — admit for monitoring; initiate treatment; identify and treat precipitating event. BWPS ≥ 45: Thyroid storm — ICU admission; aggressive treatment: propylthiouracil (PTU) or methimazole, iodine (SSKI 1–2 hours after thionamide), beta-blockers (propranolol IV), corticosteroids (dexamethasone or hydrocortisone), supportive care (cooling blankets, acetaminophen, IV fluids). Treat precipitating event.
Evidence
Burch HB & Wartofsky L (Endocrinol Metab Clin North Am 1993) proposed the point scale based on expert consensus. No formal derivation or validation study exists — the scale is based on clinical experience and pathophysiology. Despite lack of formal prospective validation, BWPS remains the most widely used and internationally recognized thyroid storm diagnostic tool. The Japanese Thyroid Association proposed alternative criteria in 2012 (Akamizu criteria). ATA thyroid storm guidelines (2016) reference BWPS as the clinical standard.