Winters' formula
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Winters’ formula is a formula to assess the adequacy of respiratory compensation in the presence of a primary metabolic acidosis.
Historical Perspective
Winters’ formula, named after Robert W. Winters,[1][2] is a formula used to evaluate respiratory compensation when analyzing acid-base disorders and a metabolic acidosis is present.[3][4]
Winters’ formula
Winters’ formula can be given as
| PCO2 = 1.5 x [HCO3–] + 8 ± 2 |
where HCO3– is given in units of mEq/L and PCO2 will be in units of mm Hg.
Interpretation
Winters’ formula gives an expected value for the patient’s PCO2; the patient’s measured PCO2 is then compared to this.
- If the two values correspond, respiratory compensation is considered to be adequate.
- If the measured PCO2 is higher than the calculated value, there is also a primary respiratory acidosis.
- If the measured PCO2 is lower than the calculated value, there is also a primary respiratory alkalosis.
References
- ↑ Albert MS, Dell RB, Winters RW (1967). “Quantitative displacement of acid-base equilibrium in metabolic acidosis”. Annals of Internal Medicine. 66 (2): 312–22. PMID 6016545. Unknown parameter
|month=ignored (help) - ↑ Asch MJ, Dell RB, Williams GS, Cohen M, Winters RW (1969). “Time course for development of respiratory compensation in metabolic acidosis”. The Journal of Laboratory and Clinical Medicine. 73 (4): 610–5. PMID 5775132. Unknown parameter
|month=ignored (help) - ↑ “Case 1: Acid Base Tutorial, University of Connecticut Health Center”.
- ↑ “Acid-Base Disorders: Acid-Base Regulation and Disorders: Merck Manual Professional”.
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