Fujiwara Kazunori, Kawamoto Katsuyuki, Shimizu Yoko, Fukuhara Takahiro, Koyama Satoshi, Kataoka Hideyuki, Kitano Hiroya, Takeuchi Hiromi
Department of Otolaryngology, Head and Neck Surgery, Faculty of Medicine, Tottori University, 36-1, Nishimachi, Yonago, 683-8504, Japan.
Department of Rehabilitation, Tottori University Hospital, 36-1, Nishimachi, Yonago, 683-8504, Japan.
BMC Pulm Med. 2017 Jan 18;17(1):19. doi: 10.1186/s12890-017-0365-y.
The reflex cough test is useful for detecting silent aspiration, a risk factor for aspiration pneumonia. However, assessing the risk of aspiration pneumonia requires measuring not only the cough reflex but also cough strength. Currently, no reflex cough testing device is available that can directly measure reflex cough strength. We therefore developed a new testing device that can easily and simultaneously measure cough strength and the time until the cough reflex, and verified whether screening with this new instrument is feasible for evaluating the risk of aspiration pneumonia.
This device consists of a special pipe with a double lumen, a nebulizer, and an electronic spirometer. We used a solution of prescription-grade L-tartaric acid to initiate the cough reflex. The solution was inhaled through a mouthpiece as a microaerosol produced by an ultrasonic nebulizer. The peak cough flow (PCF) of the induced cough was measured with the spirometer. The 70 patients who participated in this study comprised 49 patients without a history of pneumonia (group A), 21 patients with a history of pneumonia (group B), and 10 healthy volunteers (control group).
With the novel device, PCF and time until cough reflex could be measured without adverse effects. The PCF values were 118.3 ± 64.0 L/min, 47.7 ± 38.5 L/min, and 254.9 ± 83.8 L/min in group A, group B, and the control group, respectively. The PCF of group B was significantly lower than that of group A and the control group (p < 0.0001), while that of group B was significantly lower than that of the control group (p < 0.0001). The time until the cough reflex was 4.2 ± 5.9 s, 7.0 ± 7.0 s, and 1 s in group A, group B, and the control group, respectively. This duration was significantly longer for groups A and B than for the control group (A: p < 0.001, B: p < 0.001), but there was no significant difference between groups A and B (p = 0.0907).
Our newly developed device can easily and simultaneously measure the time until the cough reflex and the strength of involuntary coughs for assessment of patients at risk of aspiration pneumonia.
反射性咳嗽试验有助于检测隐性误吸，这是吸入性肺炎的一个危险因素。然而，评估吸入性肺炎的风险不仅需要测量咳嗽反射，还需要测量咳嗽强度。目前，尚无能够直接测量反射性咳嗽强度的反射性咳嗽检测设备。因此，我们开发了一种新的检测设备，它可以轻松、同时测量咳嗽强度和咳嗽反射出现的时间，并验证使用这种新仪器进行筛查对于评估吸入性肺炎风险是否可行。
该设备由一根带有双腔的特殊管道、一个雾化器和一个电子肺活量计组成。我们使用处方级L-酒石酸溶液引发咳嗽反射。该溶液通过超声雾化器产生的微气溶胶经口含器吸入。用肺活量计测量诱发咳嗽的峰值咳嗽流量（PCF）。参与本研究的70名患者包括49名无肺炎病史的患者（A组）、21名有肺炎病史的患者（B组）和10名健康志愿者（对照组）。
使用该新型设备，可以测量PCF和咳嗽反射出现的时间，且无不良反应。A组、B组和对照组的PCF值分别为118.3±64.0L/min、47.7±38.5L/min和254.9±83.8L/min。B组的PCF显著低于A组和对照组（p<0.0001），而B组显著低于对照组（p<0.0001）。A组、B组和对照组咳嗽反射出现的时间分别为4.2±5.9秒、7.0±7.0秒和1秒。A组和B组的这一持续时间显著长于对照组（A组：p<0.001，B组：p<0.001），但A组和B组之间无显著差异（p=0.0907）。
我们新开发的设备可以轻松、同时测量咳嗽反射出现的时间和非自主性咳嗽的强度，以评估有吸入性肺炎风险的患者。
