Lin Yanxia, Lin Dan, Chen Biqun, Ji Chao, Yuan Congli, Wang Baochun
Department of Critical Care Medicine, Zhongshan Hospital, Xiamen University, Xiamen 361004, Fujian, China. Corresponding author: Lin Dan, Email:
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2014 May;26(5):347-50. doi: 10.3760/cma.j.issn.2095-4352.2014.05.013.
To explore the bias between the real pressure and the measured values when handheld pressure gauge (HPG) was used to monitor intermittently the pressure in the intubation balloon, so as to provide some measures for the correct use of HPG.
In the first part of the study, HPG was used to measure the pressure with the balloon connected with a three-way tube with which to control the inflation and deflation in a laboratory to measure the pressure in the air bag. After gaining the deviation in this in vitro experiment, it was tested and verified in vivo in adult patients undergoing endotracheal intubation.
After 132 times of measurements, it was found that measurement with a HPG might result in an "inherent loss" (3.928±0.291) cmH2O (1 cmH2O=0.098 kPa, t=155.273, P=0.000) between inflation value [(30.000±0.000) cmH2O] and measured value [(26.072±0.291) cmH2O]. In addition, after 214 times repeated measurements, the pressure "loss" during disconnection of the gauge was as high as (1.196±0.954) cmH2O (t=18.348, P=0.000) between filled values [(30.000±0.000) cmH2O] and measured values [(28.804±0.954) cmH2O] and it was named as "error loss". At last, the total error was verified by clinical test, and it was (5.270±2.583) cmH2O (t=29.632, P=0.000) between pressure of filled value [(30.000±0.000) cmH2O] and measured value [(24.730±2.583) cmH2O].
When the balloon pressure was monitored intermittently with HPG, the real value should be the measured value plus the "error". In addition, subglottic aspiration should be done before the connection of the balloon to the gauge to prevent the secretions on the cuff falls into the deeper airway, and to maintain the cuff pressure at 30 cmH2O.
探讨使用手持式压力计（HPG）间歇性监测气管插管气囊压力时实际压力与测量值之间的偏差，以便为正确使用HPG提供措施。
在研究的第一部分，使用HPG通过与三通管相连的气囊测量压力，在实验室中通过三通管控制充气和放气来测量气囊压力。在体外实验中获得偏差后，在接受气管插管的成年患者体内进行测试和验证。
经过132次测量，发现使用HPG测量时，充气值[（30.000±0.000）cmH₂O]与测量值[（26.072±0.291）cmH₂O]之间可能存在“固有损失”（3.928±0.291）cmH₂O（1 cmH₂O = 0.098 kPa，t = 155.273，P = 0.000）。此外，经过214次重复测量，在仪表断开连接期间压力“损失”高达（1.196±0.954）cmH₂O（t = 18.348，P = 0.000），充气值[（30.000±0.000）cmH₂O]与测量值[（28.804±0.954）cmH₂O]之间，将其命名为“误差损失”。最后，通过临床试验验证总误差，充气值压力[（30.000±0.000）cmH₂O]与测量值[（24.730±2.583）cmH₂O]之间为（5.270±2.583）cmH₂O（t = 29.632，P = 0.000）。
当使用HPG间歇性监测气囊压力时，实际值应为测量值加上“误差”。此外，在将气囊连接到仪表之前应进行声门下吸引，以防止袖带上的分泌物落入更深的气道，并将袖带压力维持在30 cmH₂O。
