Recommendations for Instituting Oxygen Therapy (from the American College of Chest Physicians and the National Heart Lung and Blood Institute):
(1) cardiac and respiratory arrest
(2) hypoxemia, with PaO2 < 7.8 kPa (58.6 mm Hg), oxygen saturation < 90%
(3) hypotension, with systolic blood pressure < 100 mm Hg
(4) low cardiac output and metabolic acidosis (bicarbonate < 18 mmol/L)
(5) respiratory distress with respiratory rate > 24 breaths per minute
Target PaO2: 8.0 - 10.6 kPa
Administration of high dose oxygen therapy to patients with chronic obstructive pulmonary disease (COPD) who have type II respiratory failure may reduce the hypoxic drive to breath and increase ventilation-perfusion mismatching, with resultant carbon dioxide retention and respiratory acidosis.
(1) Oxygen therapy is started with low FIO2 between 24-28%, then progressively increased based on sequential blood gas analysis.
(2) The goals are to correct hypoxemia (to above 6.665 kPa) while keeping the pH above 7.26.
(3) Non-invasive positive pressure ventilation may help achieve adequate oxygenation and prevent retention of carbon dioxide by raising minute ventilation in these patients.
