Estimating Serum Phosphate levels and correcting them may predict and/or check disease progression in acidosis: An ICU study

Abstract

Phosphate is of vital importance in various critical metabolic processes as well as in formation of the structure of vital compounds. It is the primary intracellular anion which is involved in creation of high energy nucleotides involved in energy transfer. We analyzed its essential biochemical role in maintenance of acid-base balance, ventilation and oxygenation status and attempted to study the levels of phosphate and arterial blood gas measurements as well as find the correlation between the two. 100 adult patients of both sexes, admitted in the ICUs of Maharishi Markandeshwar Institute of Medical Sciences and Research (MMIMSR), were taken and their serum inorganic phosphate and arterial blood gas measurements were taken. After collection and analysis of data it was seen that mean values of all four parameters showed insignificant gender-wise or age-wise variations. However, it was observed that in cases of acidosis, serum phosphate and pH were positively and significantly correlated (p< 0.05). This could be primarily attributed to the effect of acidosis on the sodium-phosphate cotransporters and NAD metabolism. Although mean levels of phosphate in alkalosis were also lower than in the normal group no correlation could be found between phosphate and pH in these cases. Thus, we postulate that any reduction of phosphate in ICU patients hints strongly at an underlying acid-base imbalance and if the patient is acidotic, the phosphate levels may be taken as indicators of the depth of acidosis almost as an adjunct to ABG. Thus, reductions observed on serial measurements of phosphate in such patients may indicate worsening acidosis and suitable interventions (including possible phosphate supplementation in addition to bicarbonate) tailored accordingly to improve the ventilation and acid base-status.