Severe non-hypoxic bradycardia during disconnection from the ventilator during the recovery phase of ARDS

Four patients with adult respiratory distress syndrome developed sinus bradycardia during weaning procedures with no evidence of hypoxemia. Bradycardia occurred immediately after the patients' endotracheal tubes were disconnected from the ventilator and most of the time resolved after reconnection. However, 3 patients eventually deteriorated, requiring advanced life support and for one of them, cardiac pacing. The precise mechanism of these bradycardic episodes remains unclear but was unrelated to hypoxemia or acid-base disorder.