Chen Xin, Xu Rui, Chen Rong-chang, Cen Yan-yi, Zhong Nan-shan
Department of Respiratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2007 Mar;27(3):340-4.
To evaluate the effects of different interventional strategies, namely controlled high-concentration oxygen therapy, continuous positive airway pressure (CPAP) and bi-level positive airway pressure (BiPAP) ventilation, on respiratory response and work of breathing (WOB) in canine models of early-stage acute lung injury (ALI).
After successful duplication of ALI models with oleic acid (diagnostic criteria: Pa(O2)/Fi(O2)<or=300 mmHg), 24 adult mongrel dogs were randomized into 3 equal groups for treatment with controlled high-concentration oxygen therapy (O2), CPAP, and BiPAP, respectively. The parameters of respiratory response and WOB were recorded continuously at the baseline, early-stage ALI, and 1-4 hours after treatment.
BiPAP resulted in the most significant effects in reducing the respiratory rate (RR) and f/V(T) (P<0.001), followed by CPAP and O2 interventions (P<0.001). None of the 3 treatments showed obvious effects on V(E) (P>0.05), which maintained the level of early ALI/ARDS stage. BiPAP greatly improved V(T) and V(T)/Ti, showing better effects than CPAP and O2. No significant differences were noted among the 3 groups in T(I)/T(tot) (P>0.05). BiPAP showed superior effect to CPAP in lowering the peak transdiaphragmatic pressure (Pdi). CPAP and BiPAP both effectively counteracted intrinsic positive end expiratory pressure (PEEPi) (P<0.01), while O2 produced no obvious such effects (P>0.05). BiPAP showed the most evident effects, followed by CPAP, in reducing WOB, but oxygen therapy produced no obvious effects. CPAP (P<0.01) and BiPAP (P>0.05) both effectively reduced the proportion of ingredients in WOB related to PEEPi.
BiPAP and CPAP can produce favorable effects in relieving dyspnea, reducing WOB and improving respiratory response to control the deterioration of ARDS. BiPAP has more significant therapeutic effects than CPAP and oxygen therapy.
评估不同干预策略，即控制性高浓度氧疗、持续气道正压通气（CPAP）和双水平气道正压通气（BiPAP），对早期急性肺损伤（ALI）犬模型呼吸反应和呼吸功（WOB）的影响。
用油酸成功复制ALI模型（诊断标准：Pa(O2)/Fi(O2)≤300 mmHg）后，将24只成年杂种犬随机分为3组，每组8只，分别接受控制性高浓度氧疗（O2组）、CPAP和BiPAP治疗。在基线、ALI早期及治疗后1 - 4小时连续记录呼吸反应和WOB参数。
BiPAP在降低呼吸频率（RR）和f/V(T)方面效果最显著（P<0.001），其次是CPAP和O2干预（P<0.001）。3种治疗方法对分钟通气量（V(E)）均无明显影响（P>0.05），V(E)维持在ALI/急性呼吸窘迫综合征（ARDS）早期水平。BiPAP显著改善了潮气量（V(T)）和V(T)/吸气时间（Ti），效果优于CPAP和O2。3组间吸气时间占总呼吸时间的比例（T(I)/T(tot)）差异无统计学意义（P>0.05）。BiPAP在降低跨膈压峰值（Pdi）方面效果优于CPAP。CPAP和BiPAP均能有效抵消内源性呼气末正压（PEEPi）（P<0.01），而O2无明显效果（P>0.05）。BiPAP在降低WOB方面效果最明显，其次是CPAP，氧疗无明显效果。CPAP（P<0.01）和BiPAP（P>0.05）均能有效降低WOB中与PEEPi相关成分的比例。
BiPAP和CPAP在缓解呼吸困难、降低WOB及改善呼吸反应以控制ARDS病情恶化方面具有良好效果。BiPAP的治疗效果比CPAP和氧疗更显著。
