Correlation of the Changing Trends of ScvO 2 , Serum Lactate, Standard Base Excess and Anion Gap in Patients with Severe Sepsis and Septic Shock Managed by Early Goal Directed Therapy (EGDT): A Prospective Observational Study.

BACKGROUND: To observe the correlation of central venous oxygen saturation (ScvO2 ), serum lactate, standard base excess (SBE), and anion gap (AG) in septic and septic shock patients resuscitated with early goal-directed therapy (EGDT).

MATERIALS AND METHODS: A review was made of 130 severe septic shock patients (15-65 years) according to the consensus conference criteria admitted in intensive care unit. Blood samples were obtained from arterial and central venous line for ScvO2, serum lactate, SBE, and AG on admission and after achieving all aims of EGDT i.e.; mean arterial pressure >65 mmHg, central venous pressure = 8-12 mmHg, ScvO2 >70%, and urine output >0.5 mL.kg-1 .h-1 , and on 12 and 24 h. The statistical analysis was done using SPSS for windows version 16 software. For comparison, Pearson test was used. A P < 0.05 was considered as statistically significant.

RESULTS: There were a positive correlation between ScvO2 and SBE, a negative correlation between ScvO2 and AG, a negative correlation between ScvO2 and lactate, a negative correlation between SBE and AG, a negative correlation between AG and lactate, and a negative correlation between SBE and lactate. The ScvO2 was initially low but was in an improving trend after a resuscitative period, SBE was initially low and correction of SBE was linear. AG was high in the beginning and goes on decreasing after resuscitation. Lactate level was also high initially and in decreasing trend after a resuscitative period.

CONCLUSIONS: ScvO2 and SBE are correlated and can be used as a surrogate marker. ScvO2 and AG are related but not absolutely codependent. ScvO2 and lactate are correlated but they are not absolutely codependent. SBE and AG are correlated and can be used as a surrogate marker. AG and lactate are not related to each other. Hence, AG cannot be considered as a surrogate for lactate testing. SBE and lactate are related and can be used as a surrogate marker.