Comparison between cuff pressures of endotracheal tubes inflated with saline or AİR in LOW-FLOW anesthesia

This prospective study was performed as comparison between two groups which totally involved 60 patients who are ASA I-II, between 18-65 years old and with operation time ranged between 60-180 min. Enrolled patients were divided into two groups as cuff pressures of endotracheal tubes randomly inflated with either saline (Group S) or air (Group H) to 25 cm H2O with the help of "cuff manometer". Maintenance of anesthesia was provided in both groups by initially allowing patient to breathe a total of 6 L/min flow consisted of %50 of O2/N2O mixture and %2-3 of sevoflurane; then reducing flow to 1 L/min; and finally ceasing N2O and giving 6 L/min of flow with %100 of oxygen during last 10 minutes of surgery. Heart rate, oxygen saturation, mean arterial pressure, BIS values, intracuff pressure values, peak cuff pressure values, amount of time to reach peak cuff pressure, EtCO2 , inspired values of oxygen and nitrogen protoxide, internal PEEP and peak airway pressure values were recorded before induction, after intubation, in every 10 minutes after induction and just before extubation. Cuff pressure differences of patients at 10th, 20th, 30th, 40th, 50th, 60th, 70th, 80th, 90th, 100th, 110th and 120th minutes as well as peak cuff pressure levels were significantly increased patients in Group H compared with Group S. However; there was no significant difference between Group H and Group S in terms of amount of time to reach peak cuff pressure. In terms of Visual Analogue Scale (VAS) differences; VAS scores of patients during swallow at postoperative 2nd and 24th hours as well as at 2nd hours without swallowing were statistically significantly increased in Group H compared with Group S. In conclusion, it was found that intraoperative cuff pressures in low-flow anesthesia procedures utilizing N2O were significantly low and postoperative complications were decreased in group whose intubation tube cuffs inflated with saline compared with group whose intubation tube cuffs inflated with air. Key words: low flow anestehesia, endotracheal tube cuff pressures, N2O,saline