Airway Resistance and Respiratory Compliance in Children with Acute Viral Bronchiolitis Requiring Mechanical Ventilation Support

Abstract

A bstract Background Acute viral bronchiolitis (AVB) is a very frequent disease that affects the lower airways of young children increasing the inspiratory and expiratory resistance in variable degree as well as reducing the pulmonary compliance. It would be desirable to know whether these variables are associated with the outcome. Objectives To evaluate the respiratory mechanics in infants with AVB requiring mechanical ventilation (MV) support and to evaluate if respiratory mechanics predict outcomes in children with AVB supported on MV. To evaluate the respiratory mechanics in infants with AVB submitted to MV. Materials and methods A prospective observational study was conducted in two pediatric intensive care units (PICUs) between February 2016 and March 2017. Included were infants (1 month to 1 year old) admitted with AVB and requiring MV for >48 hours. Auto-PEEP, dynamic compliance (Cdyn), static compliance (Cstat), expiratory resistance (ExRes), and inspiratory resistance (InRes) were evaluated once daily on the second and third day of MV. Results A total of 64 infants (median age of 2.8 months and a mean weight of 4.8 ± 1.7 kg) were evaluated. A mean positive inspiratory pressure (PIP) of 31.5 ± 5.2 cmH 2 O, positive end-expiratory pressure (PEEP) of 5.5 ± 1.4 cmH 2 O, resulting in a mean airway pressure (MAP) of 12.5 ± 2.2 cmH 2 O and delta pressure of 22.5 ± 4.4 cmH 2 O without difference between the two hospitals. Measurements of respiratory mechanics showed high values of InRes and ExRes (median 142 [IQ 25–75 106–180] cmH 2 O/L/s and 158 [IQ 25–75 130–195.3] cmH 2 O/L/s, respectively), accompanied by decreased Cdyn and Cstat (0.46 ± 0.19 and 0.81 ± 0.25 mL/kg/cmH 2 O, respectively). None of the variables was associated with mortality, length of MV, or length of PICU stay. Conclusion Infants with AVB requiring MV support present very high InRes and ExRes values. These findings might be the reason for the aggressive ventilatory parameters, especially PIP, required to ventilate this group of children with lower airway obstruction. Clinical significance Monitoring respiratory mechanics could represent a useful tool to guide the ventilatory strategy to be adopted in patients with AVB. How to cite this article Andreolio C, Piva JP, Bruno F, da Rocha TS, Garcia PCR. Airway Resistance and Respiratory Compliance in Children with Acute Viral Bronchiolitis Requiring Mechanical Ventilation Support. Indian J Crit Care Med 2021;25(1):88–93.

Plateau Pressure and Driving Pressure in Volume- and Pressure-Controlled Ventilation: Comparison of Frictional and Viscoelastic Resistive Components in Pediatric Acute Respiratory Distress Syndrome

“…Second, PCV in comparison to VCV, underestimated the viscoelastic resistive component (P1–P PLAT ) by an average of 1.5 cm H 2 O. Third, contrary to other reports (9, 18), we found that the resistive (PIP–P1) and threshold (iPEEP) frictional components were negligible regardless of MV mode, even though most patients had critical bronchiolitis (19). Last, the peak inspiratory flow in decelerating flow was higher than squared-shaped flow, despite V t and Ti were kept the same.…”

The Relevance of Airway Resistance in Children Requiring Mechanical Ventilatory Support

“…We and others have reported pulmonary mechanics (i.e., inspiratory resistance [Rinsp], expiratory resistance [Rexp], static lung compliance, and dynamic lung compliance) pediatric patients undergoing invasive MV (7)(8)(9). Now, in our current study, we describe values of pulmonary resistance in pediatric patients undergoing invasive MV, adjusted for age and weight.…”

“…All parents/family provided informed consent. Some of this research has been published previously (7).…”

“…We and others have reported pulmonary mechanics (i.e., inspiratory resistance [Rinsp], expiratory resistance [Rexp], static lung compliance, and dynamic lung compliance) pediatric patients undergoing invasive MV (7–9).…”

Flow‐resistive loading and diaphragmatic muscle function in term and preterm infants

“…The upper quartile of the measured inspiratory resistance in ventilated infants with bronchiolitis at a median age of 2.8 months has been reported at 176-186 cm H 2 O/L/s. 7 The percentage of change in the PTIdi after the application of the resistance was calculated as the difference in the PTIdi divided by the PTIdi before the application of the resistance times 100. During the measurements, the participants were closely monitored for chest wall distortion and oxygen desaturation.…”