Effect of Endotracheal Tube Size, Respiratory System Mechanics, and Ventilator Settings on Driving Pressure

Objectives: We sought to investigate factors that affect the difference between the peak inspiratory pressure measured at the Y-piece under dynamic flow conditions and plateau pressure measured under zero-flow conditions (resistive pressure) during pressure controlled ventilation across a range of endotracheal tube sizes, respiratory mechanics, and ventilator settings. Design: In vitro study. Setting: Research laboratory. Patients: None. Interventions: An in vitro bench model of the intubated respiratory system during pressure controlled ventilation was used to obtain the difference between peak inspiratory pressure measured at the Y-piece under dynamic flow conditions and plateau pressure measured under zero-flow conditions across a range of endotracheal tubes sizes (3.0–8.0 mm). Measurements were taken at combinations of pressure above positive end-expiratory pressure (10, 15, and 20 cm H2O), airway resistance (no, low, high), respiratory system compliance (ranging from normal to extremely severe), and inspiratory time at constant positive end-expiratory pressure (5 cm H2O). Multiple regression analysis was used to construct models predicting resistive pressure stratified by endotracheal tube size. Measurements and Main Results: On univariate regression analysis, respiratory system compliance (β –1.5; 95% CI, –1.7 to –1.4; p
Source: Pediatric Critical Care Medicine - Category: Pediatrics Tags: Online Laboratory Investigation Source Type: research