Volume-time curve: an alternative for endotracheal tube cuff management.
BACKGROUND
Despite numerous studies on endotracheal tube cuff pressure (CP) management, the literature has yet to establish a technique capable of adequately filling the cuff with an appropriate volume of air while generating low CP in a less subjective way. The purpose of this prospective study was to evaluate and compare the CP levels and air volume required to fill the endotracheal tubes cuff using 2 different techniques (volume-time curve versus minimal occlusive volume) in the immediate postoperative period after coronary artery bypass grafting.


METHODS
A total of 267 subjects were analyzed. After the surgery, the lungs were ventilated using pressure controlled continuous mandatory ventilation, and the same ventilatory parameters were adjusted. Upon arrival in the ICU, the cuff was completely deflated and re-inflated, and at this point the volume of air to fill the cuff was adjusted using one of 2 randomly selected techniques: volume-time curve and minimal occlusive volume. We measured the volume of air injected into the cuff, the CP, and the expired tidal volume of the mechanical ventilation after the application of each technique.


RESULTS
The volume-time curve technique demonstrated a significantly lower CP and a lower volume of air injected into the cuff, compared to the minimal occlusive volume technique (P < .001). No significant difference was observed in the expired tidal volume between the 2 techniques (P = .052). However, when the subjects were submitted to the minimal occlusive volume technique, 17% (n = 47) experienced air leakage as observed by the volume-time graph.


CONCLUSIONS
The volume-time curve technique was associated with a lower CP and a lower volume of air injected into the cuff, when compared to the minimal occlusive volume technique in the immediate postoperative period after coronary artery bypass grafting. Therefore, the volume-time curve may be a more reliable alternative for endotracheal tube cuff management.
Escola Paulista de Medicina, Federal University of São Paulo, São Paulo, Brazil.
Douglas Willian
DW
Bolzan
Walter Jose
WJ
Gomes
Sônia Maria
SM
Faresin
Antônio Carlos
AC
de Camargo Carvalho
Angelo Amato Vincenzo
AA
De Paola
Solange
S
Guizilini
D000368:Aged; D001026:Coronary Artery Bypass; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D008875:Middle Aged; D011312:Pressure; D011446:Prospective Studies; D013990:Tidal Volume