Neonatal Resuscitation With T-Piece Systems: Risk of Inadvertent PEEP Related to Mechanical Properties

Frontiers in Pediatrics

article

Thomas Drevhammar¹  Markus Falk²  Snorri Donaldsson³  Mark Tracy⁴  Murray Hinder⁴ 

[1] Anaesthesiology and Intensive Care Medicine, Department of Surgical and Perioperative Sciences, Umeå University;Department of Women's and Children's Health, Karolinska Institute;Neonatology Department, Karolinska University Hospital;Department of Pediatrics and Child Health, The University of Sydney;Neonatal Intensive Care Unit, Westmead Hospital

关键词: resuscitation;    infant;    newborn;    positive pressure ventilation;    equipment design;    expiratory time constant;    resistance to breathing;    inadvertent PEEP;   

DOI  :  10.3389/fped.2021.663249

学科分类：社会科学、人文和艺术（综合）

来源: Frontiers

【 摘 要 】

Background: Resuscitation of infants using T-piece resuscitators (TPR) allow positive pressure ventilation with positive end-expiratory pressure (PEEP). The adjustable PEEP valve adds resistance to expiration and could contribute to inadvertent PEEP. The study indirectly investigated risk of inadvertent peep by determining expiratory time constants. The aim was to measure system expiratory time constants for a TPR device in a passive mechanical model with infant lung properties. Methods: We used adiabatic bottles to generate four levels of compliance (0.5–3.4 mL/cm H 2 O). Expiratory time constants were recorded for combinations of fresh gas flow (8, 10, 15 L/min), PEEP (5, 8, 10 cm H 2 O), airway resistance (50, 200 cm H 2 O/L/sec and none), endotracheal tube (none, size 2.5, 3.0, 3.5) with a peak inflation pressure of 15 cm H 2 O above PEEP. Results: Low compliances resulted in time constants below 0.17 s contrasting to higher compliances where the expiratory time constants were 0.25–0.81 s. Time constants increased with increased resistance, lower fresh gas flows, higher set PEEP levels and with an added airway resistance or endotracheal tube. Conclusions: The risk of inadvertent PEEP increases with a shorter time for expiration in combination with a higher compliance or resistance. The TPR resistance can be reduced by increasing the fresh gas flow or reducing PEEP. The expiratory time constants indicate that this may be clinically important. The risk of inadvertent PEEP would be highest in intubated term infants with highly compliant lungs. These results are useful for interpreting clinical events and recordings.

【 授权许可】

CC BY