Proton NMR spectroscopic studies of serum as an aid to perioperative cellular metabolic monitoring.

Perioperative concentration changes of cellular metabolites in serum were studied by proton NMR spectroscopy in four cancer patients who underwent tumorectomies under general anesthesia. In proton NMR spectra of serum, the resonances assignable to fatty acid in lipoprotein, lactate, alanine, glucose, glycoprotein and other metabolites were observed. The concentrations of fatty acid and alanine did not show significant changes during the operations compared with those in healthy volunteers. The concentrations of lactate, glucose and glycoprotein increased during the operations above the concentration ranges in the control subjects. The time-course of concentration change for lactate, glucose and glycoprotein was roughly classified into two patterns: i) the maximums of lactate and glucose concentration were observed in the latter halves or at the ends of the operations; ii) the maximums of glycoprotein concentrations were observed three hours after the incision, regardless of the operative time. The results showed cellular metabolic changes became larger as the operations proceeded responding to surgical stress. Prompt cellular metabolic monitoring is indispensable for the screening of cellular metabolic disorders caused by excessive surgical stress and proton NMR spectroscopy can be a new tool for monitoring perioperative cellular metabolism.