Air Versus Distilled Water Cuff Inflation using Cuffill (Digital Cuff) in Adult Patients Undergoing General Anaesthesia

Introduction: An essential part of anaesthesia is endotracheal intubation. The Endotracheal Tube (ETT) cuff pressure must not be higher than the predicted 22-30 mmHg tracheal perfusion pressure. If the ETT’s cuff is inflated with air while under nitrous oxide+oxygen anaesthesia, the cuff pressure may increase dangerously and result in ischaemia of the tracheal mucosa. Hence, distilled water as an alternative agent to air for inflation of cuffs of ETTs was used in the present study.

Aim: To determine whether inflating the ETT cuff with distilled water, instead of air changes the pressure over time. To evaluate changes in cuff pressure over time, and to assess the knowledge about endotracheal cuff pressure monitoring with cuffill.

Materials and Methods: The randomised clinical study was conducted from February 2022 to April 2022. The study included 50 patients undergoing elective surgery under general anaesthesia who were randomly divided into two groups. In Group-A, distilled water was used and in Group-B, air was used to inflate the cuffs of ETTs. General anaesthesia was given with nitrous oxide, oxygen and relaxant technique. The intra-cuff pressures of ETT cuffs were recorded by AG cuffill. Increase of pressures with time were recorded and analysed.

Results: Mean ET cuff pressure by cuffill with air (Group-B) was 26±2.43 mmH2O after 0 minutes of intubation. After 15 minutes of intubation mean ET cuff pressure was 31.80±3.39 mmH2O. Mean ET cuff pressure by cuffill with distilled water (Group-A) was 25.56±2.02 mmHg after 0 minutes of intubation. After 15 minutes of intubation, mean ET cuff pressure was 28.5±2.26 cmH2O. There was a pressure difference observed between the groups with a mean difference of 3.217, t-value of 4.743 and a p-value of 0.001.

Conclusion: For the purpose of inflating the cuffs of ETTs when the patient is under general anaesthesia with the use of nitrous oxide, oxygen, and relaxant method, distilled water may be considered a more desirable agent than air.