Influence of Artificial Ventilation and PEEP on Pulmonary Gas Exchange and Oxygen Uptake

Patients with acute respiratory failure (ARF) requiring mechanical ventilatory support remain a major challenge to intensive care medicine. Several new modalities of artificial Ventilation have been introduced over the last years. However, simple intermittent positive pressure Ventilation (IPPV) with positive endexpiratory pressure (PEEP) is still the most widely used technique in patients with seriously impaired pulmonary gas exchange. The main purpose of PEEP is by increasing arterial oxygenation to ensure adequate oxygen delivery to the tissues without employing potential toxic oxygen concentrations (FiO2 > 0.6). Although in clinical use for more than two decades, the precise mechanism whereby PEEP reduces alveolar – arterial oxygen difference is still controversial [1,2].