High-Flow Nasal Cannula Versus Conventional Oxygen Therapy After Extubation in Liver Transplantation

Humidified oxygen therapy via high-flow nasal cannula (HFNC) is a recently available technique delivering heated and humidified high flow oxygen through simple nasal prongs. In immunocompetent patients HFNC can help generating low levels of Continuous Positive Airway Pressure (CPAP) due to the high flow of fresh gas, improving comfort and oxygenation, and it attenuates signs of respiratory distress compared with non-rebreathing oxygen face mask such as Venturi mask. Moreover, HFNC is considered to have several physiological advantages compared with other standard oxygen therapies, including the provision of positive end-expiratory pressure (PEEP), constant inspiratory oxygen fraction (FiO2), and good humidification. More importantly, it can reduce the anatomical dead space. For its advantages over conventional oxygen delivery system in patients undergoing abdominal surgery or Thoracoscopic Lobectomy, the investigators are currently and according to clinical practice using HFNC oxygen delivery in Liver transplantation after extubation, in our Post-Operative Intensive Care Unit (PICU). Due to recipients' generally poor preoperative clinical conditions, the extensive surgical field and long operating times, post-operative respiratory disorders are very common after liver transplantation and they significantly contribute to the related morbidity and mortality, both in the acute postoperative stage and in the long term. Several factors are involved in the onset of postoperative pulmonary complications (PPCs), and many preoperative and intraoperative variables have been associated with different degrees of severity of respiratory impairment after liver transplantation. In the early stages after transplantation, pulmonary complications may prolong intubation time and increase the risk of systemic infective complications. Prolonged mechanical ventilation due to refractory respiratory failure is an extremely morbid event, as this event is a marker of poor recipient recovery