Salivary monitoring related to major surgery

Prolonged surgical procedures involving stress, extended general anaesthesia and a long pre-surgical fasting period may have systemic effects such as alterations in saliva flow rate and composition. These may compromise the patient's electrolytes and fluid balance and cause dehydration, systemic stress and oxidative changes.

Saliva was collected prior and following surgery from 20 patients and 20 control subjects. The saliva samples were analysed for flow rates and levels of the following: calcium (Ca), magnesium (Mg), total protein, albumin and lactate dehydrogenase (LDH), total antioxidant status (TAS), uric acid (UA), superoxide dismutase (SOD), carbonyls, matrix metalloproteinases (MMPs) -2, -3 and -9 and heat shock proteins (HSPs) 70 and 90.

Salivary levels of Ca, Mg, protein, albumin and LDH were higher in post-surgical patients by 70% (P = 0·002), 88% (P = 0·0001), 120% (P = 0·13), 111% (P = 0·039) and 492% (P = 0·006) respectively than that in healthy controls. Salivary antioxidants in the surgical patients were higher while salivary carbonyls remained unchanged. Salivary TAS levels in pre- and post-surgical patients were higher by 63% (P = 0·001) and 85% (P = 0·0001) respectively, UA concentrations by 92% (P = 0·014) and 81% (P = 0·036) respectively and SOD values by 47% (P = 0·61) and 112% (P = 0·049) respectively. Salivary concentrations of MMP3 were higher in pre- and post-surgical patients by 23% (P = 0·067) and 30% (P = 0·044) respectively.

Local salivary, oral and systemic-induced alterations should be prevented. Moreover, salivary collection and analysis may be a new, efficient tool in the monitoring of patients undergoing major surgery. Further related research is necessary.