小儿喉乳头状瘤吸入七氟烷麻醉诱导期间呼吸力学变化

目的 通过热线风速仪观察喉乳头状瘤患儿和普通小儿吸入七氟烷麻醉诱导期呼吸力学的变化,旨在获得预测通气和捕管困难的客观量化指标及对控制通气加深麻醉效果的评估.方法 选择普通患儿(C组)和喉乳头状瘤患儿(L组)各20例,静脉注射氯胺酮1 mg/kg,吸入氧气2 L/min+7%七氟烷实施麻醉诱导.热线风速仪采集四时段呼吸力学数据:静注氯胺酮1 min后(T1),开始吸入7%七氟烷时(T2),吸入7%七氟烷3min后(T3),控制通气2min后(T4).结果 L组T1期呼吸的平均速度[(1.48±0.20)m/s和(1.26±0.18m/s)]、最大速度[(1.72±0.25)m/s和(1.97±0.31)m/s]都高于c组(P<0.05),呼吸频率、吸气时间差异无统计学意义(P>0.05). L组T3、T4期平均吸气速度和最大吸气速度的比值(0.612±0.030和0.613±0.032)小于C组(P<0.05).L组T3期最大吸气速度、呼吸频率下降的幅度[(25±6)%和(19±4)%]少于C组(P<0.05).L组T4期各项指标较T3期无明显变化(P>0.05).结论 喉乳头状瘤患儿吸入七氟烷麻醉诱导期是靠加强呼吸做功来代偿通气不足的,其上气道梗阻情况随麻醉加深更加突出,通过控制通气辅助加深麻醉效果不明显.

The changes of respiratory mechanics during sevoflurance anesthesia induction in children with laryngeal papillomatosis

Objective To observe the changes of respiratory mechanics with anemometer during sevoflurane inhalational anesthesia induction in children with laryngeal papillomatosis and in normal children, and to obtain the objective quantization parameter of predicting difficult ventilation/intubation and the effect of anesthesia deepened by controlled ventilation. Methods Twenty dyspneic children with laryngeal papillomatosis (L group) and 20 normal children (C group) were included in this study. General anesthesia was induced with intravenous ketamine 1 mg/kg and inhalation of oxygen 2 L/min +7% sevoflurane. The respiratory mechanics parameters were measured with an anemometer at four time points of anesthesia induction: T1, 1 min after intravenous ketamine,T2, initiation of sevoflurane inhalation,T3, 3 min after sevoflurane inhalation,T4, 2 min after controlled ventilation. Results The mean velocities [(1.48±0.20) m/s and(1.26±0.18) m/s], maximum velocities[(1.72±0.25) m/s and(1.97±0.31) m/s] of both inspiratory and expiratory airflows at T1 were higher in group L compared with group C (P<0.05), but inspiratory time and respiratory frequency at T1 did not significantly differ between groups (P>0.05). At T3 and T4, the ratios of mean inspiratory velocity to maximum inspiratory velocity were smaller in in group L (0.612±0.030 and 0.613±0.032) than in group C(P<0.05). At T3, decreased degrees of both maximum inspiratory velocity and respiratory frequency were less in group L [(25±6)% and (19±4)%] than in group C (P<0.05). In group L, all observed parameters at T3 and T4 were not significantly different (P>0.05). Conclusion During sevoflurane inhalational anesthesia induction in children with laryngeal papillomatosis, hypoventilation is compensated by increased work of breathing. With anesthesia being deepened,upper airway obstruction is becoming more serious. It has not obvious effect that anesthesia induction was deepened with inhalational sevoflurane by controlled ventilation.