Changes in Lung Function Parameters after Total Intravenous Anaesthesia and Balanced Anaesthesia with Desflurane: A Prospective Randomised Study

OBJECTIVE: Following anaesthesia, there is a decrease in pulmonary function. Unlike volatile anaesthetics, propofol decreases the upper airway tone, and total intravenous anaesthesia (TIVA) with propofol may decrease coughing on emergence. Coughing may reduce postoperative atelectasis. Thus, TIVA may lead to greater decreases in lung function postoperatively as compared to balanced anaesthesia with desflurane. METHODS: Sixty patients of either sex, aged 18–60 years and American Society of Anaesthesiologists (ASA) status I/II, who were to undergo mastoid surgery, were randomly allocated to Group B and Group T. Anaesthesia was maintained with desflurane, nitrous oxide and oxygen in Group B, and with TIVA in Group T. Pulmonary function tests (PFT) were done preoperatively, and 1, 3 and 24 hours postoperatively. RESULTS: Demographic data and preoperative PFT were comparable in both groups. One hour after surgery, there was a greater decrease in FEV1 and peak expiratory flow rate (PEFR) in Group T (p=0.044 and 0.042, respectively). Three hours postoperatively, the decrease in MEFR and PEFR was again greater in Group T (p=0.005 and 0.008, respectively), while the MEFR recovered to preoperative values in Group B. By 24 hours, the forced vital capacity (FVC), MEFR and PEFR recovered to preoperative values in Group T, while FVC remained reduced in Group B (p=0.006). CONCLUSION: Both anaesthetic techniques cause a postoperative impairment in the lung function, but while TIVA causes a greater reduction in PFT in the early postoperative period, recovery is also earlier. On the other hand, balanced anaesthesia with desflurane was associated with a greater reduction in PFT at 24 hours.