[Effects of various lidocaine compounds on cuff pressure of a reinforced tracheal tube].

Effects of various lidocaine compounds on cuff pressure of a tracheal tube were studied. Thirty reinforced tracheal tubes (Mallinckrodt Medical, Ireland) were divided into five groups and the cuffs were treated with normal saline, 2% lidocaine jelly, plain lubricant jelly, 4% lidocaine solution or 8% lidocaine pump spray. The cuff pressures of each tube was measured with 5, 10, 15, and 20 ml of air at the time of 0, 30, 60, 90, and 120 min after the treatment. The cuff pressures with 20 ml of air (P20) were compared among the groups. Thirty min after the treatment on the cuffs, P20 of the tubes with lidocaine spray significantly decreased than that of the control tubes with normal saline. In 2 of 10 tubes on which lidocaine had been sprayed, the cuffs were damaged 90 min after the treatment. Any jelly or solution on the cuffs did not influence the cuff pressure-volume relationship. We conclude that lidocaine pump spray should not be used as a lubricant on the cuff of a reinforced tracheal tube.