Intraoperative airway cuff pressure monitoring: are we doing it right?

Abstract

Background: Insertion of endotracheal tubes (ETT) and supra-glottic airway devices (SGA) are common practice amongst anaesthesiologists when administering general anaesthesia to facilitate numerous surgical procedures. In an era where quality of patient care and patient safety takes precedence, monitoring of intraoperative cuff pressure of an airway device remains an essential component in anaesthetic practice. Methods: Data was collected through a single page questionnaire from postgraduate trainees in anaesthesiology involved in administering general anaesthesia for elective surgical procedures over a three- month period at the National Hospital of Sri Lanka. Study population included all patients undergoing elective surgical procedures requiring an endotracheal tube (ETT- high volume low pressure cuff) or a supra-glottic airway (SGA) device to facilitate ventilation under general anaesthesia. Data was analysed using SPSS version 22.0 and was expressed as median, inter-quartile range [IQR], frequency, percentage and 95% confidence interval (CI) where appropriate. Correlation test was used to determine the relationship between cuff pressure and size of airway device. A non-parametric test was used to measure the significance between various carrier gas combinations and cuff pressure values for both ETT and SGA devices. Results: 196 completed questionnaires were received over a three-month period. Mean age of the patients were 44.1 years and 64.8% were females. Majority (53.6%) were ASA (American Society of Anaesthesiologists) grade I. ETT were used in 82.7% and SGA devices were used in 13.8% of cases. ETT’s were used for laparotomies/laparoscopic procedures in 32.7% followed by 22.2% in gynaecological surgeries and 17.9% in thyroid and related surgery. SGA devices were mostly used for gynaecological procedures (40.7%). Theatre supporting staff was responsible for the initial cuff inflation in 83.2%. During the initial cuff pressure measurement 58.6% of endotracheal tubes had pressures within the recommended level (20-30cmH 2 O). 33.3% had cuff pressures of >30cmH 2 O while 8% had cuff pressures of 2 O. In contrast to the above findings, the recommended cuff pressure values for SGA devices was achieved only in 29.6% and in 37% the cuff pressures were more than 70cmH 2 O which was alarming. 33.3% had cuff pressure values less than recommended. Conclusion and Recommendations: It is evident that cuff pressure values in both endotracheal tubes and supra-glottic devices were not optimal and it was more so with the latter. Adherence to current evidence-based recommendations to ensure patient safety is vital in anaesthetic practice. To overcome the above problem, cuff pressure must be monitored at the commencement of surgery and at hourly intervals during general anaesthesia, which will identify under or over-inflation of the cuff and minimize related complications. Similarly, a sign-post to remind the anaesthetist, “Have you checked the cuff pressure today?” should be displayed in all operating theatres next to the airway trolley to avoid failure to reach standards.