Comparison of four inflation techniques on endotracheal tube cuff pressure using a feline airway simulator

Abstract

Objectives The aim of this study was to compare four inflation techniques on endotracheal tube cuff (ETC) pressure using a feline airway simulator. Methods Ten participants used four different endotracheal cuff inflation techniques to inflate the cuff of a low-pressure, high-volume endotracheal tube within a feline airway simulator. The simulator replicated an average-sized feline trachea, intubated with a 4.5 mm endotracheal tube, connected to a circle breathing system and pressure-controlled ventilation with oxygen and medical air. Participants inflated the ETC: by pilot balloon palpation (P); by instilling the minimum occlusive volume (MOV) required for loss of airway leaks during mechanical ventilation; until a passive release of pressure with use of a loss-of-resistance syringe (LOR); and with use of a syringe with a digital pressure reader (D) specifically designed for endotracheal cuff inflation. Intracuff pressure was measured by a manometer obscured to participants. The ideal pressure was considered to be between 20 and 30 cmH2O. Data were analysed by Shapiro–Wilk, Kruskal–Wallis and χ2 tests, as appropriate. Results Participants were eight veterinarians and two veterinary nurses with additional training in anaesthesia. Measured median intracuff pressures for P, MOV, LOR and D, respectively, were 25 cmH2O (range 4–74 cmH2O), 41 cmH2O (range 4–70 cmH2O), 31 cmH2O (range 18–64 cmH2O) and 22 cmH2O (range 20–30 cmH2O). D performed significantly better ( P <0.001) than all other techniques, with no difference between the other techniques. Conclusions and relevance Use of D for cuff inflation achieved optimal cuff pressures. There may be high operator-dependent variability in the cuff pressures achieved with the use of P, MOV or LOR inflation techniques. As such, a cuff manometer is recommended when using any of these techniques.

Methods Used for Endotracheal Tube Cuff Inflation and Pressure Verification in Veterinary Medicine: A Questionnaire on Current Practice

“…Our results revealed very limited use of cuff manometers but common use of MOV to establish a cuff seal in dogs, cats and farm animals. This result is not in line with evidence obtained in humans [ 27 , 28 , 29 ], as well as in dogs and cats [ 1 , 2 , 30 , 31 ] establishing the inferiority of MOV to the use of a manometer in achieving a pre-specified (i.e., target) cuff pressure. Furthermore, when comparing MOV in cats and dogs to the use of commercially available syringe inflation devices, MOV proved inferior [ 2 , 32 ].…”

“…This result is not in line with evidence obtained in humans [ 27 , 28 , 29 ], as well as in dogs and cats [ 1 , 2 , 30 , 31 ] establishing the inferiority of MOV to the use of a manometer in achieving a pre-specified (i.e., target) cuff pressure. Furthermore, when comparing MOV in cats and dogs to the use of commercially available syringe inflation devices, MOV proved inferior [ 2 , 32 ]. Whereas these studies clearly concluded that a cuff manometer should be used to achieve optimal ETT cuff pressure, the use of MOV was three times more common than cuff pressure measurement in dogs and cats in the current study.…”

“…Several studies in human medicine have likewise demonstrated pilot balloon palpation to be an unreliable method to assess ETT cuff pressure [ 8 , 33 , 34 ], proving inferior to other techniques, such as loss of resistance [ 35 ], MOV [ 27 ] and the use of a manometer [ 27 , 36 ]. In two studies in cats, pilot balloon palpation performed worse than cuff pressure measurement with a manometer in achieving a target cuff pressure [ 2 , 31 ]. Despite these compelling data proving the inferiority of the technique for the purpose of cuff seal assessment, in our survey, pilot balloon palpation was still selected by 13–16% of respondents.…”

“…In dogs, digital palpation of the pilot balloon and inflation to minimum (audible) occlusive volume proved ineffective to ensure inflation of the ETT cuff within the optimal pressure range [ 1 ]. In a similar study in cats, pilot balloon palpation, minimum occlusive volume and loss of resistance techniques all performed poorly at achieving predetermined ETT cuff pressures [ 2 ]. To the best of our knowledge, there is no available literature on cuff inflation techniques and their relative performance in horses and farm animals.…”

Anestesisykepleieres metoder for å kontrollere cufftrykk – en observasjonsstudie

“…Studier har vist at helsepersonell som bruker palpasjon og minimal-lekkasjemetoden av indikatorballongen i endotrakealtuber hadde problemer med å opprettholde riktige cufftrykk (8,9). Dette inkluderer også helsepersonell med lang erfaring i å håndtere endotrakealtuber (10,11).…”