SESSION TYPE: Sepsis/Shock Posters
PRESENTED ON: Wednesday, October 24, 2012 at 01:30 PM - 02:30 PM
PURPOSE: Severe sepsis and septic shock are life-threatening conditions within the intensive care unit that frequently require analysis of acid-base status and oxygenation. Arterial blood gases have traditionally been used for this evaluation but their collection carries risk and may be difficult. Venous blood gases may serve as an alternative but have not been studied in this population. The purpose of this study was to evaluate correlation and agreement between ABG, peripheral VBG (pVBG) and central VBG (cVBG) values in severe sepsis and septic shock to determine if a VBG can be used as an alternative to an ABG.
METHODS: We performed a single center prospective observational study on medical intensive care unit (MICU) subjects with severe sepsis and septic shock to evaluate the correlation and agreement between ABG, pVBG and cVBG for pH, pCO2, pO2 and O2 saturation. Subjects requiring an ABG underwent simultaneous pVBG and cVBG sampling. Demographic characteristics, disease severity scores, use of vasopressors and mechanical ventilation were collected. Statistic analysis was performed using descriptive statistics, intraclass correlation, and Bland-Altman agreement analysis.
RESULTS: Sixty-seven subjects were enrolled with a mean (±SD) age of 59.5±16.9 and 52.2% female. Severity of illness scores revealed a mean SOFA of 7.9±3.3 and SAPS II of 49.3±16.5. The mortality rate for the MICU and hospital was 11.9% and 16.4% respectively. Community acquired pneumonia was the most common etiology (34.3%). Intraclass correlation analysis of ABG/pVBG, ABG/cVBG and pVBG/cVBG comparisons revealed a strong correlation for pH and pCO2 (ICC > 0.85). Bland-Altman analysis revealed excellent agreement in all three comparisons of pH (bias, 0.03±0.04, 0.03±0.02 and 0.00±0.03 respectively) but not for pCO2, pO2 or O2 saturation.
CONCLUSIONS: In subjects with severe sepsis or septic shock, central and peripheral venous pH showed a high degree of correlation and agreement with arterial pH.
CLINICAL IMPLICATIONS: In critically ill subjects with severe sepsis and septic shock, the pH from a central or peripheral VBG can be used to screen for acid-base disturbances.
DISCLOSURE: The following authors have nothing to disclose: Heath White, Pedro Quiroga, Juhee Song, Alfredo Vazquez-Sandoval, Alejandro Arroliga, Shirley Jones
No Product/Research Disclosure InformationScott & White Memorial Hospital, Temple, TX