经面罩鼻咽部加压预防高压舱耳气压伤

The prevention of the ear barotrauma by positive pressure on nasopharynx

目的:探讨人体在高压舱进行环境增压时,鼻咽部压力大于咽鼓管通气阻力能否预防耳气压伤。方法:咽鼓管通气阻力<6kPa的男性健康志愿者8例,分为4组,每组2例,互为被试者和对照者。被试者经面罩给予6kPa的鼻咽部正压,对照者正常呼吸,高压舱以0.5kPa/s的速率增压至5kPa,被试者和对照者均不采用其他任何主动或被动开放咽鼓管的措施,测鼓室腔压力;高压舱以同样速率增压至20kPa,被试者条件不变,对照者可进行主动或被动开放咽鼓管的措施,测鼓室压。结果:高压舱增压至5kPa时,被试者和对照者鼓室压分别为(-11.2±5.3)daPa和(-168.6±71.5)daPa,差异有统计学意义(P<0.01);增压至20kPa时,被试者和对照者鼓室压分别为(-8.3±6.1)daPa和(-7.6±6.4)daPa,差异无统计学意义(P>0.05)。结论:当人体的环境压力增加时,经面罩提供大于咽鼓管通气阻力的鼻咽部压力可预防耳气压伤的发生。

Objective：To explore if the ear barotrauma could be prevented or not if the provided nasopharyngeal pressure is higher than the Eustachian tube resistance during the pressure increases in the hyperbaric chamber. Method：Eight volunteers of healthy men were divided into 4 groups, with 2 persons in each group who werethe testee and the control for each other. The positive pressure of 6kPa was given via mask to the nasopharynx of the testee, while the control took normal breath. The pressure in the hyperbaric chamber was increased by 5kPa with the velocity of 0.5kPa/s. No positive or negative measurement to open Eustachian tube was allowed for both testees and controls. The pressure within the tympanic cavity was measured. Similarly, the pressure in the hyperbaric chamber was increased by 20kPa with the same velocity. The testees were not allowed to adjust the Eustachian tube, while the controls could do so. The pressure within the tympanic cavity was measured once again. Result： When 5 kPa in the hyperbaric chamber was reached, the pressure within the tympanic cavity of the testee and the control was -11.2 daPa and -168.6 daPa（ P〈 0.01）, respectively. When 20 kPa was reached, the pressure within the tympanic cavity of the testee and the control was -8.3 daPa and -7.6 daPa（ P〉0.05）, respectively. Ear barotrauma could be prevented by providing positive pressure which is higher than the Eustachian tube resistance through mask to the nasopharynx.