Department of Pediatrics, Pediatric Intensive Care Unit, Umberto I Policlinico, Sapienza University of Rome, Rome, Italy.
Department of Molecular Medicine, Virology Laboratory, Sapienza University, Rome, Italy.
Pediatr Pulmonol. 2021 Aug;56(8):2611-2620. doi: 10.1002/ppul.25439. Epub 2021 Apr 30.
To determine whether in infants with bronchiolitis admitted to a pediatric intensive care unit (PICU) the starting rate for high-flow nasal cannula (HFNC) therapy set by the attending physicians upon clinical judgment meets patients' peak inspiratory flow (PIF) demands and how it influences respiratory mechanics and breathing effort.
We simultaneously obtained respiratory flow and esophageal pressure data from 31 young infants with moderate-to-severe bronchiolitis before and after setting the HFNC rate at 1 L/kg/min (HFNC-1), 2 L/kg/min (HFNC-2) or upon clinical judgment and compared data for PIF, respiratory mechanics, and breathing effort.
Before HFNC oxygen therapy started, 16 (65%) infants had a PIF less than 1 L/kg/min (normal-PIF) and 15 (45%) had a PIF more than or equal to 1 L/kg/min (high-PIF). Normal-PIF-infants had higher airway resistance (p < .001) and breathing effort indexes (e.g., pressure rate product per min [PTP/min], p = .028) than high-PIF-infants. Starting the HFNC rate upon clinical judgment (1.20-2.05 L/kg/min) met all infants' PIFs. In normal-PIF-infants, the clinically judged flow rate increased PIF (p = .081) and tidal volume (p = .029), reduced airway resistance (p = .011), and intrinsic positive end-expiratory pressure (p = .041), whereas, in both high-PIF and normal-PIF infants, it decreased respiratory rate (p < .001) and indexes of breathing effort such as PTP/min (in normal-PIF infants, p = .004; in high-PIF infants, p = .001). The 2 L/kg/min but not 1 L/kg/min rate induced similar effects.
The wide PIF distribution in our PICU population of infants with bronchiolitis suggests two disease phenotypes whose therapeutic options might differ. An initial flow rate of nearly 2 L/kg/min meets patients' flow demands and improves respiratory mechanics and breathing effort.
在因毛细支气管炎而入住儿科重症监护病房（PICU）的婴儿中，根据临床判断为高流量鼻导管（HFNC）治疗设定的起始流速是否满足患者的吸气峰流速（PIF）需求，以及它如何影响呼吸力学和呼吸努力。
我们同时从 31 名患有中度至重度毛细支气管炎的婴儿获得呼吸流量和食管压力数据，然后在设定 HFNC 流速为 1 L/kg/min（HFNC-1）、2 L/kg/min（HFNC-2）或根据临床判断后进行比较，并比较 PIF、呼吸力学和呼吸努力的数据。
在开始 HFNC 氧疗之前，有 16 名（65%）婴儿的 PIF 小于 1 L/kg/min（正常-PIF），15 名（45%）婴儿的 PIF 大于或等于 1 L/kg/min（高-PIF）。正常-PIF 婴儿的气道阻力（p < 0.001）和呼吸努力指数（例如，每分钟压力速率乘积 [PTP/min]，p = 0.028）高于高-PIF 婴儿。根据临床判断（1.20-2.05 L/kg/min）开始 HFNC 流速可满足所有婴儿的 PIF。在正常-PIF 婴儿中，临床判断的流速增加了 PIF（p = 0.081）和潮气量（p = 0.029），降低了气道阻力（p = 0.011）和固有呼气末正压（p = 0.041），而在高-PIF 和正常-PIF 婴儿中，它降低了呼吸频率（p < 0.001）和呼吸努力指数，如 PTP/min（在正常-PIF 婴儿中，p = 0.004；在高-PIF 婴儿中，p = 0.001）。2 L/kg/min 但不是 1 L/kg/min 的流速产生了类似的效果。
我们的 PICU 毛细支气管炎婴儿人群中 PIF 分布广泛，表明存在两种疾病表型，其治疗选择可能不同。初始流速接近 2 L/kg/min 可满足患者的流量需求，并改善呼吸力学和呼吸努力。
