study to compare the effect of two different types of humidifier on the endotracheal tube patency

Conditions: Cancer of Head and Neck

Summary: 60 post operative patients who are kept intubated overnight \& are spontaneously breathing will be either supplied humidified oxygen heated humidifier(hh) or conventional mist nebulizer. temperature of inspired gas at the y piece will be measured. sterile water will be used for hh \& mist nebuliser. the suctioning of endotracheal tube (ett) will be done once every 2 hourly by nurse/ doctor/trained personnel and additional suctioning if required.

60 post operative patients who are kept intubated overnight \& are spontaneously breathing will be selected in tata memorial hospital (tmh), mumbai. 30 patients will be supplied through humidified oxygen using fisher \& paykel mr 370 heated humidifier(hh) \& 30 patients through conventional mist nebulizer. temperature of inspired gas at the y piece will be measured as surrogate marker for quality of humidification. continuous monitoring of temperature will be done using standard monitor. the reusable hh will be subjected to disinfection between patients. sterile water will be used for hh \& mist nebuliser. the suctioning of endotracheal tube (ett) will be done once every 2 hourly by nurse/ doctor/trained personnel. based on patient's clinical condition , additional suctioning will be done. frequency of additional suctioning , reason for suctioning will be noted. information regarding the age, sex, type of surgery of the patient, co-morbidity if any size of ett, the time of commencement of humidification , duration of use of humidifier, time of extubation, any complication leading to discontinuation of humidifier, frequency of refilling of nebulizer chamber, volume of ett before intubation etc. will be noted. the amount of endotracheal tube blockade caused by secretion will be measured immediately following extubation. the volume of endotracheal tube secretion / amount of blockade will be assessed by the following process- * the bevel end \& murphy's eye of the endotracheal tube will be sealed using sterile insulating tape so that it become water tight. the tube will be gradually filled with measured amount of sterile fluid using small volume syringe to increase the accuracy of measurement. the amount of fluid it can hold will be measured \& noted. * the volume of extubated tube will be measured in the similar way. * the measured volume of the extubated endotracheal tube will be subtracted from the actual volume of the particular sized ett ( measured before intubation). * the result obtained after this subtraction will be the volume of secretion or the volume of ett that has been blocked.

Eligibility criteria:
inclusion criteria: 1. american society of anaesthesiologists (asa) 1 and 2 adult patients 2. undergoing surgery for head and neck cancer 3. requiring overnight endotracheal tube \& breathing spontaneously exclusion criteria: 1. patients with major cardiac diseases( coronary artery disease, valvular diseases) 2. patients having gross chronic obstructive pulmonary disease (copd), bronchiectasis, cystic fibrosis. 3. smokers(abstinence period less than 3 months) 4. patient in drugs having sialogogue properties. 5. patient on drugs having anti-sialogogue properties