BACKGROUND: Oxygen therapy provided via high-flow nasal cannula (HFNC) improves gas exchange lung compliance and results in increased lung expiratory volumes. Previous data indicate that hyperbaric and humid states improve the olfactory thresholds compared to hypobaric and dry conditions. This prospective, observational study aimed to determine the impact of oxygen delivery through HFNC on olfactory function in subjects admitted to the ICU for acute respiratory failure (ARF).
背景：通過經鼻高流量(HFNC)提供的氧療改善了氣體交換肺順應性，並使肺通氣量增加。先前的數據表明，與低壓和乾燥條件相比，高壓和潮溼狀態可改善嗅覺閾值。這項前瞻性、觀察性研究旨在確定通過HFNC氧療對因急性呼吸功能衰竭(ARF)入住ICU的受試者嗅覺功能的影響。
METHODS: 30 subjects who were admitted to the ICU for ARF underwent an olfactory sniff test before and after oxygen therapy with HFNC. Baseline olfactory function of subjects with ARF was also compared against 30 healthy controls. Odor threshold (OT), odor discrimination (OD), odor identification (OI) and global olfactory score (TDI) were recorded for all subjects.
方法：30例因ARF入住ICU的受試者在HFNC氧療前後接受嗅覺試驗。還將ARF受試者的基線嗅覺功能與30例健康對照進行了比較。氣味閾值(OT)、氣味辨別(OD)、氣味識別(OI)和總體嗅覺評分(TDI)為記錄所有受試者。
Results:The study was conducted on 60 subjects (mean age 64.3 6 9.3 y) and included 20 female subjects (33.3%) and 40 male subjects (66.7%). There was no significant difference in age (65.4 6 11.2 y vs 63.2 6 6.9 y, P ¼ .35) or gender (20 male subjects and 10 female subjects in each group, P > .99) between groups. The OT, OD, OI, and TDI scores were significantly higher in the control group compared to the baseline scores of the subjects with ARF (P < .001 for all comparisons, Table 1). Subjects with ARF received oxygen supplementation through an HFNC for a mean of 54 6 13 h. A significant improvement was noted both in SpO2 (81.3 6 4.1% vs 90.4 6 4.5%, P < .001) and PaO2 (57.2 6 3.6 mm Hg vs 77.9 6 8.2 mm Hg, P < .001) 24 h after HFNC. In subjects with ARF, administration of oxygen with HFNC led to significant improvements in OT (4.9 6 1.6 vs 5.4 6 1.6, P ¼ .02), OD (9.7 6 1.8 vs 10.4 6 1.5, P ¼ .001), OI (10.9 61.6 vs 11.2 6 1.5, P ¼ .02), and TDI (25.5 6 3.8 vs 27.1 6 T2,F1 3.5, P < .001) scores (Table 2, Fig. 1)
結果:研究對象為60名（平均年齡64.3加減9.3歲)，包括20名女性(33.3%)和40名男性(66.7%）。 在群體之間年齡(65.4加減11.2歲vs 63.2 加減6.9歲）或性別(每組20名男性受試者和10名女性受試者)均無顯著差異。對照組的OT、OD、OI和TDI評分明顯高於ARF(P<受試者的基線評分，表1)。 接受ARF的受試者通過HFNC補充氧氣，平均54加減13小時。在HFNC後24小時未觀察到SpO2(81.3加減4.1% vs 90.4加減4.5%）和Pa O2(57.2加減3.6毫米汞柱 vs 77.9加減8.2毫米汞柱）有明顯改善。 在ARF的受試者中，HFNC吸氧可顯著改善OT(4.9加減1.6vs5.4加減1.6)，OD(9.7加減1.8vs10.4加減1.5，)，OI(10.9加減1.6 vs 11.2 加減 1.5)and TDI (25.5 加減 3.8 vs 27.1 加減3.5）評分（表2，圖1）
表1.不同年齡、性別在使用HFNC前嗅覺測試結果的比較
表2.急性呼吸衰竭受試者HFNC前後的嗅覺檢查結果
圖1.急性呼吸衰竭受試者實施經鼻高流量(HFNC)後氣味閾值(OT)、氣味辨別(OD)、氣味識別(OI)和總體嗅覺評分(TDI)的變化。
Conclusions :Our findings indicate that subjects with ARF have relative olfactory dysfunction compared to healthy controls. Our results also indicate that implementation of HFNC to relieve hypoxemia in subjects presenting with ARF can lead to a significant improvement in olfactory function. Larger studies are needed in select patient groups using various pressure levels and durations.
結論:我們的研究結果表明，與健康對照組相比，ARF受試者存在相關嗅覺功能障礙。我們的結果還表明，實施HFNC緩解ARF受試者的低氧血症可導致嗅覺功能顯著改善。需要在選擇的患者組中使用不同的壓力水平和持續時間進行更大規模的研究。
Published on February 18, 2020 as DOI: 10.4187/respcare.07309