| dc.description.abstract | In Dutch veterinary practice endotracheal tubes (ET-tubes) with a cuff on the distal end to ensure sealing of the trachea are commonly used for inhalation anaesthesia of dogs and cats. This cuff should be inflated until the pressure from the cuff on the tracheal wall (POT) is 15-30 cm H2O, so leaking is prevented and no tracheal damage is provoked. A manometer is seldom used to achieve this.
The objective of this study is to evaluate whether it is possible to achieve the desired POT by applying the Minimal Occlusion Volume method (MOV), or whether the use of a manometer should be preferred.
For this purpose, the intracuff pressure of intubated patients (234 dogs and 48 cats) was measured with a manometer while inflating the cuff using the MOV method and subsequently measured after 30, 60, 90 and 120 minutes of anaesthesia (if applicable) and shortly before extubation. The POT achieved with the MOV method was compared with the desired pressure (15 – 30 cm H2O). In addition, we evaluated whether the factors species (dog/cat), shape of the head (brachy-, meso- or doligocephalic), body weight, tube size and experience of the person inflating the cuff influenced the POT. Also, we evaluated if there was a significant rise or fall in intracuff pressure during anaesthesia, and whether this was depending on the type of cuff used (Low Pressure (LP)/Low Volume High Pressure (LVHP)), intracuff pressure on t=0 and POT.
Only in 20% of the cases the POT was correct when the MOV method was used. The number of patients with a low POT was equal to the number of patients with a high POT. Only the factors species and shape of the head influenced the POT significantly. The influence of the factors body weight, tube size and experience of the person inflating the cuff was insignificant. During anaesthesia, intracuff pressure decreased with 5,6 cm H2O on average. Both intracuff pressure on t=0 and POT influenced this decrease.
Because inflating a cuff using the MOV method is accurate but imprecise, and because intracuff pressure decreases during anaesthesia, the use of a manometer is preferred for veterinary practice. But because POT is only equal to intracuff pressure when High Volume Low Pressure (HVLP) cuffs are used, it would be most efficient to use this type of cuffs together with the manometer. | |
