The Impact of Positive End-Expiratory Pressure on Functional Residual Capacity and Ventilation Homogeneity Impairment in Anesthetized Children Exposed to High Levels of Inspired Oxygen

Abstract

During the application of a very low PEEP of 3-cm H2O, FRC and ventilation distribution decreased significantly at an Fio2 of 1.0 compared with that at an Fio2 of 0.3. This decrease could be counterbalanced by the administration of PEEP of 6-cm H2O, indicating that a low level of PEEP is sufficient to maintain FRC and ventilation distribution regardless of the oxygen concentration.

Paediatric lung recruitment: a review of the clinical evidence

“…9 By approximately two years of age, chest wall and lung compliance is similar to adults however, older infants and children continue to have a significantly smaller airway radius in proportion to their weight, less elastic retraction force, and a lower relaxation volume. [10][11][12] These factors all combine to predispose infants and children to atelectasis and hence an increased risk of VILI. Subsequently these populations show potential to benefit most from lung recruitment.…”

“…[25][26][27] Increasing PEEP effectively allows the clinician to manipulate the functional residual capacity (FRC) and thereby minimise physiological deadspace, improving ventilation/perfusion mismatch and decreasing shunt fraction. 6,12,[28][29][30] Boriosi and colleagues chose this method of recruitment to assess the safety and efficacy of the open lung tool in paediatrics. Ultimately they used a modified version but found that oxygenation improved and peak inspiratory pressures were significantly reduced by 17% up to 12 hours post recruitment.…”

“…6,12 During positive pressure ventilation there is an inhomogeneous distribution of gas, although the distribution of alveolar opening pressures is deemed Gaussian. 9 Duff and colleagues routinely conducted lung recruitment A c c e p t e d M a n u s c r i p t twice daily to address the progressive de-recruitment associated with LPVS.…”

“…Concerns include the potential for barotrauma, pneumothoraces and the possible contributory factor to both VILI and ventilator associated pneumonia (VAP). 12,20,36,44,60 Other concerns include the potential to impact negatively on haemodynamics and intracranial pressure. 17 By increasing the intrathoracic pressure during the recruitment manoeuvre an inevitable consequence is a commiserate reduction in venous return and subsequent cardiac output.…”

Ventilating the Lungs Safely: What’s New for Infants and Children?

“…Accordingly, administering PEEP even in children with healthy lungs is mandatory in order to counterbalance the heterogeneity in ventilation-induced airway closure. Many studies have highlighted the beneficial effect of PEEP in restoring end-expiratory lung volume in children after general anesthesia [11], and to counteract the atelactasis induced by oxygen resorption [23]. In children with diseased lungs, PEEP improves lung function and oxygenation and potentially reduces the duration of mechanical ventilation [24].…”