OBJECTIVE. To determine whether the use of opioids could reduce the hypoxemia and hemodynamic instability associated with routine intensive care procedures in neonates with respiratory distress. DESIGN. Randomized and placebo-controlled study. METHODS. Physiological, plasma beta-endorphin, cortisol, and glucose responses to routine treatment procedures were studied in 84 mechanically ventilated distressed neonates randomized into groups receiving 1 mg/kg meperidine or 0.9% saline 15 minutes before tracheal suction or routine nursing care. RESULTS. The duration of hypoxemia (transcutaneous partial pressure of O2