【摘要】 目的应用多层螺旋CT对患者不同通气状态下上呼吸道放射性成像,证实在全身麻醉无自主呼吸的条件下,双相气道正压(bi-level positive airway pressure,BiPAP)无创机械通气能克服上呼吸道阻力,实施有效的机械通气。方法选择拟实施全身麻醉的择期手术患者10例,分别对患者清醒自主呼吸、麻醉诱导后自主呼吸停止、BiPAP无创通气时头颈部正位和侧位作螺旋CT扫描。监测扫描过程的无创血压(NIBP)、脉搏氧饱和度(SpO2)、心率(HR)、自主呼吸频率(RR)。测量上呼吸道各软组织区(软腭后区RP、舌根后区RG、会厌区EPG)的最窄气道横截面左右径、前后径线长度及相应横截面积。结果头部正位麻醉诱导后各软组织区的最窄横截面左右径、前后径线长度及相应横截面积均比清醒时缩小(P<0.05),BiPAP通气时各截面径线和面积与清醒期比较差异仍有统计学意义(P<0.05,P<0.01)。头部侧位BiPAP通气时各径线和截面积与清醒时比较,差异无统计学意义。EPG区和RG区在BiPAP通气期的侧位截面积明显比正位时增大(P<0.05,P<0.01)。诱导期正、侧位SpO2均明显下降(P<0.01);头部正位BiPAP通气时与诱导期的SpO2比较虽有改善,但差异无统计学意义(P>0.05);头部侧位BiPAP通气时SpO2较诱导期明显升高(P<0.01),基本恢复到清醒期水平(P>0.05)。结论麻醉诱导后上呼吸道的通气面积明显减少,气道通畅度下降;头颈部侧位时上呼吸道各软组织区最狭窄处的通气截面积比正位时显著改善,以会厌区最明显。无明显上呼吸道梗阻性病史的成年患者全身麻醉时,头部侧位BiPAP无创通气能克服上呼吸道阻力,实施有效的机械通气,保证通气和氧合正常。更多还原

【Abstract】 Objective To form radiological image of upper airway in patients ventilated with bi-level positive airway pressure (BiPAP)in order to validate the effectiveness of BiPAP noninvasive ventilation in overcoming airway resistance and provide effective ventilation in patients under general anesthesia . Methods In 10 patients scheduled for elective surgery under general anesthesia, spiral computed tomography of cephal-neck in normotopic and lateral position was performed in following situations: (1) spontaneous respiration; (2) respiration cease after anesthesia induction; and (3) noninvasively ventilated with BiPAP. Noninvasive blood pressure (NIBP), oxygen saturation by pulse oximeter (SpO2), heart rate and spontaneous respiratory rate (RR) were monitored. Transverse diameter, anteroposterior diameter and transverse section area at retropalatal, retroglossal and epiglottal region were measured. Results In normotopic position, the values of transverse diameter, anteroposterior diameter and transverse section area at retropalatal, retroglossal and epiglottal region decreased after anesthesia induction (P<0.05) or under BiPAP ventilation (P<0.05,P<0.01) than those in spontaneous respiration. In lateral position, there were no differences in these values between under ventilation and in spontaneous respiration. Under BiPAP ventilation, the transverse section area of retroglossal and epiglottal region increased in lateral position than those in normotopic position (P<0.05,P<0.01). In normotopic and lateral position, SpO2 decreased apparently (P<0.01). In normotopic position, SpO2 was improved insignificantly under BiPAP ventilation than after anesthesia (P>0.05). In lateral position, SpO2 was improved under BiPAP ventilation as compared to induction period (P<0.01). Conclusion The ventilation area of upper airway decreases remarkedly after anesthesia. The transverse section area of various stricture zone,especially epiglottal region increases in lateral position than in normotopic position. In patients without obstructive upper airway, BiPAP noninvasive ventilation overcomes airway resistance, provides effective ventilation and maintains adequate oxygenation.更多还原