Variations in plasma thyroxine-binding prealbumin (TBPA) in relation to other circulating proteins in post-operative patients during rapid oral refeeding.

Variations in plasma thyroxine-binding prealbumin (TBPA) were investigated in 15 well-nourished patients who underwent minor orthopaedic surgery and resumed normal oral feeding on the first post-operative day. TBPA fluctuations were analysed together with those of other nutritional and inflammatory markers including albumin (ALB), some acute-phase reactant proteins, C-reactive protein (CRP), orosomucoid also named alpha 1-acid-glycoprotein (alpha 1GP), alpha 1-antitrypsin (alpha 1AT) as well as cortisol and haematocrit. Measurements were conducted the day before operation, after the administration of anaesthesia, 2 h after the patient regained consciousness and then daily for a period of one week (days 1 to 7). Assays showed that TBPA and ALB levels began to decline by day 1 reaching minimum values by day 3 (with 35 and 15 per cent total decreases respectively compared to the initial levels). CRP levels began to rise on day 1 reaching maximum levels by day 2, alpha 1 GP and alpha 1 AT started to increase on day 1 and 2 respectively and displayed maximum concentrations by day 3. Cortisol, on the other hand, showed a rapid, yet short-lived increase after the patient regained consciousness on the day of operation. Haematocrit levels decreased from day 1 to day 3 and these low values were maintained until the end of the study. Aside from cortisol and CRP, the initial levels of the other parameters were not yet restored by day 7. These results show that despite an early return to normal oral feeding in post-operative patients, the commonly observed pattern of variation in TBPA levels persisted, indicating that such a pattern seems to be mainly influenced by stress-induced post-operative responses rather than by nutritional supply.