Evaluating the convential practice of intraoperative ETT cuff pressure management versus intraoperative management of ETT cuff pressure using pressure manometer on change in expired tidal volume intraoperatively.

Patients whofulfill the eligibility criteria and  requiring general anesthesia and endotrachealintubation will be included in the study. Dragger machine’s leak test will bepassed before induction with systemic leak allowed upto 150 ml/min(as perdragger manual). systemic leak more than this will not be allowed. Generalanesthesia will be induced using intravenous bolus of induction agents andparalysis will be achieved with succinylcholine or a nondepolarizing musclerelaxant. Flow ratio of 1:1 of oxygen and air will be used. Male patient’strachea will be intubated with an 8 or 8.5 mm internal diameter ETT and femalepatient’s trachea will be intubated with a 7.0 or 7.5 mm internal diameter ETT( portex endotracheal tube) endotracheal tube with low pressure high volumewill be used. Anesthesia will be maintained with sevoflurane, a volatile anestheticagent, in a combination of air and oxygen and without nitrous oxide.  Tidal volume will be pre set as 7 ml/kg.Ventilation will be maintained on volume control mode . ETco2 monitoring willbe  mandatory and ETco2 will bemaintained between 30 to 35mmhg. PEEP will be allowed upto 10cms of H2O.Patient will be maintained in well relaxed state using muscle relaxant(atracuriumor vecuronium) in maintenance dose guided by PNS(peripheral nerve stimulaator). The routine practice in our institutionis that endotracheal intubation is done by anesthesiologist and ETT cuff isinflated by the qualified anesthesia technician/ anaesthesia resident . A 10 mlsyringe is used to inflate cuff with 6 cc air as a routine in our instititute.Adequacy of cuff inflation is assessed by palpation of pilot balloon as persatisfication of anaesthesiologiest and no audible leak during inspiration.

Thesepatients will be divided into 2 groups: In group 1, endotracheal tube cuff willbe inflated manually by trained OT personnel as mentioned above by palpation ofpilot balloon technique. Cuff pressure will be measured after inflation ofcuff  and than left as it is for rest of surgery. Cuff pressure willbe measured at the end of the surgery before extubation prior to giving reversalagent with cuff pressure manometer (portex cuff inflator/pressure  gauge). Intra operatively cuff will beinflated when anaesthesiologiest feel inadequate cuff pressure on palpatingpilot balloon and also on the basis of tidal volume, i.e. if more than 10% ofthe set tidal volume is lost than cuff will be inflated with 10cc syringe tillthe pre set tidal volume is achieved. In group 2, cuff will be inflated with cuffmanometer and cuff  pressure will be setat  26cm of H2O after intubation. Cuffpressure will than be measured at interval of 15 minutes. If cuff pressure isbelow 20cm of H2O or above 30 cm of H2O, than it will be reset at 26cm of H2Ousing cuff manometer. Cuff pressure will be measured at the end of the surgerybefore extubation prior to giving reversal agent . Number of times the cuffpressure required to be adjusted will be noted in both groups. Intraoperatively expired tidal volume will be noted  from display of ventilator and Etco2 valuewill be noted from multipara monitor during each measurment of ET cuff pressure.In this study,each measurement of cuff pressure will be done by same cuffmanometer.

Post operative complain of sore throat will bemeasured according to complain of patient on basis of 1 to 4 scale at the time of discharge from therecovery room after achieving adequate recovery room discharge score of  9-10.