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The Relevance of Airway Resistance in Children Requiring Mechanical Ventilatory Support
Francisco Bruno1,2, Cinara Andreolio1, Pedro Celiny R Garcia2
1Pediatric Intensive Care Unit, Department of Pediatrics, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
Insights
Pulmonary resistance is high in children on invasive mechanical ventilation (MV). Younger children under 10kg experience significantly increased resistance, impacting ventilation strategies.
Area of Science:
- Pediatric Critical Care Medicine
- Respiratory Physiology
- Mechanical Ventilation
Background:
- Invasive mechanical ventilation (MV) is crucial for managing respiratory failure in critically ill children.
- Understanding pulmonary mechanics, particularly resistance, is vital for optimizing ventilator settings and improving outcomes.
- Limited data exists on pulmonary resistance patterns across different pediatric age groups and conditions requiring MV.
Purpose of the Study:
- To characterize pulmonary resistance in pediatric patients undergoing invasive mechanical ventilation.
- To investigate the association between pulmonary resistance and patient factors like age and weight.
- To inform the development of tailored ventilatory strategies for children on MV.
Main Methods:
- A cross-sectional study was conducted in two pediatric intensive care units (PICUs) in Brazil.
- 113 children aged 1 month to 15 years requiring MV for over 24 hours were enrolled.
- Pulmonary mechanics, including inspiratory and expiratory resistance, were measured during neuromuscular blockade within the first 48 hours of MV.
Main Results:
- The median age of the children was 5 months, with a median weight of 6.5 kg.
- Median inspiratory and expiratory pulmonary resistances were 94.0 and 117 cm H2O/L/s, respectively.
- Increased pulmonary resistance was negatively associated with weight and age, with children under 10 kg exhibiting significantly higher resistance (p < 0.001).
Conclusions:
- Elevated pulmonary resistance is common in pediatric patients requiring invasive mechanical ventilation.
- Younger children, particularly those under 10 kg, demonstrate markedly higher pulmonary resistance.
- Pulmonary resistance should be a key consideration when establishing ventilatory strategies for pediatric patients on MV.
Objectives:
To describe pulmonary resistance in children undergoing invasive mechanical ventilation (MV) for different causes.
Design:
A cross-sectional study.
Setting:
Two PICUs in the South region of Brazil.
Patients:
Children 1 month to 15 years old undergoing MV for more than 24 hours were included. We recorded ventilator variables and measured pulmonary mechanics (inspiratory and expiratory resistance, auto positive end-expiratory pressure [PEEP], and dynamic and static compliance) in the first 48 hours of MV.
Interventions:
Measurements of the respiratory mechanics variables during neuromuscular blockade.
Measurements And Main Results:
A total of 113 children were included, 5 months (median [interquartile range (IQR) [2.0-21.5 mo]) old, and median (IQR) weight 6.5 kg (4.5-11.0 kg), with 60% male. Median (IQR) peak inspiratory pressure (PIP) was 30 cm H 2 O (26-35 cm H 2 O), and median (IQR) PEEP was 5 cm H 2 O (5-7 cm H 2 O). The median (IQR) duration of MV was 7 days (5-9 d), and mortality was nine of 113 (8%). The median (IQR) inspiratory and expiratory resistances were 94.0 cm H 2 O/L/s (52.5-155.5 cm H 2 O/L/s) and 117 cm H 2 O/L/s (71-162 cm H 2 O/L/s), with negative association with weight and age (Spearman -0.850). When we assess weight, in smaller children (< 10 kg) had increased pulmonary resistance, with mean values over 100 mH 2 O/L/s, which were higher than larger children ( p < 0.001).
Conclusions:
Increased pulmonary resistance is prevalent in the pediatric population undergoing invasive MV. Especially in children less than 1 year old, this variable should be considered when defining a ventilatory strategy.
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