tailieunhanh - Báo cáo y học: "Ethics review: Strong ion difference in urine: new perspectives in acid–base assessment"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care cung cấp cho các bạn kiến thức về ngành y đề tài: Ethics review: Strong ion difference in urine: new perspectives in acid–base assessment. | Available online http content 10 2 137 Commentary Strong ion difference in urine new perspectives in acid-base assessment Luciano Gattinoni1 Eleonora Carlesso2 Paolo Cadringher2 and Pietro Caironi2 1 Dipartimento di Anestesia Rianimazione e Terapia del Dolore Fondazione IRCCS - Ospedale Maggiore Policlinico Mangiagalli Regina Elena di Milano Istituto di Anestesiologia e Rianimazione Università degli Studi di Milano Milano Italy 2Istituto di Anestesiologia e Rianimazione Università degli Studi di Milano Milano Italy Corresponding author Luciano Gattinoni gattinon@ Published 7 April 2006 This article is online at http content 10 2 137 2006 BioMed Central Ltd Critical Care 2006 10 137 doi cc4890 Abstract The plasmatic strong ion difference SID is the difference between positively and negatively charged strong ions. At pH temperature 37 C and partial carbon dioxide tension 40 mmHg the ideal value of SID is 42 mEq l. The buffer base is the sum of negatively charged weak acids HCO3- A- H2PO4- and its normal value is 42 mEq l. According to the law of electroneutrality the amount of positive and negative charges must be equal and therefore the SID value is equal to the buffer base value. The easiest assessment of metabolic acidosis alkalosis relies on the base excess calculation buffer baseactual - buffer baseideal SIDactual - SIDideal. The SID approach allows one to appreciate the relationship between acid-base and electrolyte equilibrium from a unique perspective and here we describe a comprehensive model of this equilibrium. The extracellular volume is characterized by a given SID which is a function of baseline conditions endogenous and exogenous input endogenous production and infusion and urinary output. Of note volume modifications vary the concentration of charges in the solution. An expansion of extracellular volume leads to acidosis SID decreases whereas a contraction of extracellular volume leads to alkalosis