Advances in pulmonary management and weaning from ECLS

Abstract

ECMO for neonatal and pediatric respiratory failure provides gas exchange to allow lung recovery from reversible pulmonary ailments. This is a comprehensive discussion on the various strategies and advances utilized by pediatric ECLS specialists today. ECMO patients require continual monitoring, serial gasses and radiographs, near-infrared spectroscopy (NIRS - to monitor oxygen delivery to regional tissue beds), and more quality ECLS directed care. As the foundation to lung recovery, good EMCO closely monitors ECLS flow rates, sweep gasses, and membrane lung function. Mixed venous oxygen saturation (Sv0₂) greater than 65% indicates good oxygen delivery and sweep gas adjustments maintain PaCO2 of 40–45 mm Hg. Lung recovery ventilatory settings do not fully rest the lungs but maintain normal or nontoxic pressure and oxygen levels. Neonatal recovery settings are PIP (cm H₂0) of 15–20, PEEP of 5–10, ventilator rate of 12–20 and an inspiratory time of 0.5–1 s, and FiO2 of 0.3–0.5. Pediatric recovery settings are PIP (cm H₂0) < 25, PEEP of 5–15, ventilator rate of 10–20 and an inspiratory time of 0.8–1 s, and FiO2 of <0.5. Some studies demonstrate a higher recovery PEEP level decreases duration of ECMO, but do not demonstrate a mortality difference. Multiple adjunctive therapies such as surfactant, routine pulmonary clearance and respiratory physiotherapy, iNO, prone positioning, bronchoscopy, POCUS, CT imaging, and extubation or “awake ECLS” can significantly affect pulmonary recovery. Patience is necessary as lung recovery may take weeks or even months on the nontoxic settings. On these settings, dynamic recovery will be revealed by improvement in tidal volume, minute ventilation and radiographic pulmonary aeration, prompting discussion about weaning. When this pulmonary compliance recovery becomes evident, decreasing ECLS flow while also decreasing circuit FiO2 and/or sweep gas are common components to ECMO weaning strategies.