Endotracheal tube cuff pressures - the worrying reality: a comparative audit of intra-operative versus emergency intubations.

Objectives: The primary aim was to assess the need for objective cuff pressure monitoring in the theatre complex and trauma centre at Groote Schuur Hospital, Cape Town, South Africa. Secondary aims were to determine whether the tube size, tube make or place of intubation affected cuff pressure.

Method: Endotracheal tube cuff pressures of 91 patients in the trauma centre and 100 patients in the theatre complex were randomly measured using a Mallinckrodt cuff pressure gauge. The measurements were recorded on a standardised data sheet and transferred to an electronic database for analysis.

Results: There was a significant difference between cuff pressures in the trauma centre and those in the theatre complex (p<0.001), the means being 55 cmH2O and 25 cmH2O, respectively. The site of intubation had a significant (p=0.001) effect on cuff pressures, with mean pressures as follows: on scene - 71 cmH2O; referral hospital - 57 cmH2O; and Groote Schuur trauma centre - 42 cmH2O. Only 30% of cuff pressures measured in the trauma centre were below 30 cmH2O, and, alarmingly, 17% were between 91 and 120 cmH2O. In the theatre complex, 77% of cuff pressures were in the acceptable range. Digital balloon palpation corresponded poorly (correlation coefficient 0.47) with measured cuff pressure, and statistical analysis showed that it tended to underestimate the pressure at higher cuff pressures.

Conclusion: The risk of a high cuff pressure is roughly two- to threefold higher in emergency patients than in theatre patients. These unacceptably high cuff pressures are especially concerning in view of the fact that many trauma patients are hypotensive and therefore more susceptible to mucosal ischaemia.