Sistla Gopala Krishna Murthy1
BACKGROUND & AIM
During Nitrous Oxide+ Oxygen anaesthesia and during laparoscopic surgeries using carbon dioxide for creating pneumoperitoneum, if cuff of endotracheal tube is inflated with air, cuff pressure can rise to dangerous limits and it can produce ischemia of tracheal mucosa. Hence distilled water as an alternative agent to air for inflation of cuffs of endotracheal tubes was used for our study. Our aim is to investigate the difference in increase of intra-cuff pressure with time during laparoscopic surgical procedures under general endotracheal anaesthesia with Nitrous oxide+ Oxygen+ relaxant technique when cuffs of endotracheal tube were inflated by air & distilled water.
METHODS
Fifty patients (n=50) undergoing different laparoscopic surgical procedures under general endotracheal anaesthesia were randomly divided into 2 groups. In group A, air was used & in group D, distilled water was used to inflate the cuffs of endotracheal tubes. General anaesthesia was given with Nitrous oxide+ Oxygen+ relaxant technique. The intra-cuff pressures of endotracheal tube cuffs were recorded in the beginning and at the end of laparoscopic surgical procedures. Increase of pressures with time were recorded and analysed.
RESULTS
In group in whom we inflated the cuffs with air, there was a significant increase in intra-cuff pressures with time and there was definite diffusion of gases into the cuffs. Increase of pressure with time was statistically highly significant (P=0.00001). But in group in whom we used distilled water to inflate the cuffs, there was no change in the volume of water used for inflation and water came out of cuffs at the end of the laparoscopic surgical procedures. No additional air could be aspirated from the cuffs at the end of laparoscopic surgeries in distilled water group, indicating that there was no diffusion of gases into the cuffs or the gases diffused got dissolved in distilled water. Hence there was no increase of volume distilled water. Hence there was absolutely no change of intra cuff pressure with time in distilled water group of patients. Absolutely, no change of intra-cuff volume and pressure with time in distilled water group. There was statistically significant increase of intra-cuff pressure with time (P=0.00001) in group of patients in whom we used air to inflate the cuffs of endotracheal tubes.
CONCLUSION
Distilled water may be considered as more preferable agent than air for inflation of cuffs of endotracheal tubes during laparoscopic surgical procedures under general anaesthesia with Nitrous oxide+ Oxygen+ relaxant technique.
