Strong ions, weak acids and base excess: a simplified Fencl–Stewart approach to clinical acid–base disorders†

摘要: Background. The Fencl‐Stewart approach to acid‐base disorders uses five equations of varying complexity estimate the base excess effects important components: strong ion difference (sodium and chloride), total weak acid concentration (albumin) unmeasured ions. Although this is straightforward, most people would need a calculator use equations. We proposed four simpler that require only mental arithmetic tested hypothesis these have good agreement with more complex Methods. reduced two for sodium‐chloride effect on one simple equation: (meq litre ‐1 )=[Na + ]‐[Cl ‐ ]‐38. simplified equation albumin an constants: )=0.253(42‐[albumin]g ). Using 300 blood samples from critically ill patients, we examined between our versions Bland‐Altman analyses. Results. estimates agreed well, no bias limits ‐0.5 0.5 meq . required log transformation. was, average, 90% estimate. percentage were 82‐98%.