Médecine Intensive - Réanimation, CHU d'Angers, Vent'Lab, Université d'Angers, 4 Rue Larrey, 49100 Angers, France; Adult Intensive Care Unit, University Hospital and University of Lausanne, 46 Route du Bugnon, 1011 Lausanne, Switzerland.
Médecine Intensive - Réanimation, CHU d'Angers, Vent'Lab, Université d'Angers, 4 Rue Larrey, 49100 Angers, France.
J Crit Care. 2022 Jun;69:154023. doi: 10.1016/j.jcrc.2022.154023. Epub 2022 Mar 26.
High flow nasal cannula (HFNC) may improve CO elimination by washing out CO from the upper airways. This study aimed at assessing the effect of HFNC on minute ventilation and ventilatory ratio (VR), a surrogate of dead space, in patients hospitalized for acute hypercapnic COPD exacerbation.
Physiological study comparing HFNC at 40 L/min to low flow oxygen. Variations of tidal volume (VT) and minute ventilation between the two treatments were estimated from chest plethysmography. Respiratory rate (RR) and arterial blood gases were measured. Variations in VR were calculated. Data were compared using Wilcoxon tests.
Recordings performed in 10 patients. Minute ventilation was reduced with HFNC by -16.2 [-30.9-0.4] % (p = 0.049). VT was not different but RR was lower during HFNC. PaCO was lower with HFNC compared to standard oxygen: 48.7 [46.4-58.1] vs 50.7 [48.4-57.5] mmHg (p = 0.020). VR decreased by -18.0 [-34.7 - -4.0] % (p = 0.020) with HFNC.
In patients recovering from acute COPD exacerbation, the use of HFNC reduced RR, minute ventilation, PaCO and VR compared to standard oxygen. These changes are consistent with a decrease in physiologic dead space with HFNC.
高流量鼻导管（HFNC）可能通过从上气道冲洗出 CO 来改善 CO 的清除。本研究旨在评估 HFNC 对因急性高碳酸血症性 COPD 加重而住院的患者分钟通气量和通气比（VR），即死腔的替代指标的影响。
比较 HFNC 40 L/min 与低流量吸氧的生理研究。通过胸壁测容法估计两种治疗方法下潮气量（VT）和分钟通气量的变化。测量呼吸频率（RR）和动脉血气。计算 VR 的变化。使用 Wilcoxon 检验比较数据。
记录了 10 例患者的数据。HFNC 可使分钟通气量减少 -16.2[-30.9-0.4]%（p = 0.049）。VT 无差异，但 HFNC 时 RR 较低。与标准氧相比，HFNC 时 PaCO 较低：48.7[46.4-58.1]与 50.7[48.4-57.5]mmHg（p = 0.020）。HFNC 时 VR 下降-18.0[-34.7- -4.0]%（p = 0.020）。
在急性 COPD 加重后恢复的患者中，与标准氧相比，HFNC 可降低 RR、分钟通气量、PaCO 和 VR。这些变化与 HFNC 时生理死腔减少一致。
