Strong ion difference (SID) in critically ill patients with normal arterial pH, pCO₂, BE and HCO₃^- and its impact on mortality

Česká verzia

Authors: Večeřa Lubomír; Turek Radovan
Authors place of work: Anesteziologicko-resuscitační oddělení, Krajská nemocnice Tomáše Bati, a. s., Zlín
Published in the journal: Anest. intenziv. Med., 25, 2014, č. 2, s. 88-97
Category: Intensive Care Medicine - Original Paper

Summary

Objective:
To identify acid-base disturbances according to the Stewart-Fencl approach in critically ill patients with normal arterial pH, pCO₂, HCO₃^- and BE. To compare the SID_app, SID_ef, SIG and AG_kor values in the patients who were vs. were not alive at three months from ITU admission.

Design:
Single-centre, retrospective, observational study.

Setting:
Anaesthesiology and Resuscitation Department of a Regional Hospital.

Materials and methods:
The criteria (normal arterial pH, pCO₂, BE, HCO₃^-) were met by 112 critically ill patients. In these patients, the parameters needed to calculate the SID and SIG were sampled. Thirty nine of the patients died within three months of admission, 50 patients survived longer than 3 months and 23 patients were eliminated from the subsequent part of the study. SID_app, SID_ef, SIG and AG_kor values were calculated in all these patients.

Results:
A total of 110 patients had abnormal SID_efvalues (98.21%), 107 patients had abnormal SID_appvalues (95.54%), 52 patients had SIG values above 5 mmol/l (46.43%) and 4 of them over 10 mmol/l (3.57%). There was a statistically significant difference between the non-survivors and survivors in the SID_app(p < 0.01), SIG (p < 0.005) and AG_kor (p < 0.005) values. There was no statistically significant difference between the SID_efvalues.

Conclusion:
This study confirmed that the majority of critically ill patients admitted to the ITU with normal parameters of arterial pH, pCO₂, HCO₃^- and BE have acid-base disturbances according to the Stewart-Fencl approach. We found a significant difference in SID_app, SIG and AG_kor values between the survivors and the non-survivors.

Keywords:
acid-base disturbances – Stewart-Fencl approach – strong ion difference (SID) – critically ill patients

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