COMPARISON OF THE EFFECT OF PROPOFOL, ISOFLURANE AND NITRIC OXIDE ON ENDOTRACHEAL TUBE CUFF PRESSURE IN PATIENTS UNDERGOING GENERAL ANESTHESIA FOR ELECTIVE SURGERY

Background: Endotracheal intubation is the common procedure to maintain an open airway in anesthetic patients to facilitate ventilation. Intra-cuff pressure should be enough to prevent aspiration but not so high to affect tracheal blood flow and cause mucosal damage and its attending complications. The aim of the present study was to access intra-cuff pressure in four different anesthetic groups.

Materials and Methods: In this randomized double-blinded clinical trial, 140 patients aged 18-65 years old and ASA class I, II, who were candidate for elective surgeries were eligible for the study and randomly assigned to four equal groups (n=35). Group P (propofol 150 µg/kg/min); group I (isoflurane 1%); group PN (propofol 150 µg/kg/min + N2O ratio 50-50); and group IN (isoflurane 1% + N2O ratio 50-50). Anesthesia in all of the patients were equal. The mean intra-cuff pressure was measured and compared between groups every 30 min, three times using digital manometer set on 25 cm H2O.

Results: Intra-cuff pressure in 30, 60 and 90 min after intubation in group P and I were significantly decreased (p=0.001 in both groups) but in group PN and IN, intra-cuff pressure showed significant increase during the surgery (p=0.001). Intra-cuff pressure in groups P and I were significantly lower than group PN and IN in all three measurements (P<0.05). Intra-cuff pressure in group PN was lower than group IN, but their differences were not significant (p= 0.13, 0.06, and 0.15, respectively).

Conclusion: Our study showed significant changes in intra-cuff pressure in all four anesthetic groups during the surgery, which in groups received N2O, were higher than others. It shows the importance of intra-cuff pressure monitoring during surgery.