Intermittent Mandatory Ventilation: A New Approach to Weaning Patients from Mechanical Ventilators

Mechanical ventilatory support has become a prime mode of therapy for patients with acute respiratory insufficiency. Some patients who have had their ventilation controlled are difficult to wean from mechanical to spontaneous ventilation. We have developed a method of ventilatory support which allows the patient to breathe spontaneously as desired, but which also delivers a mechanical hyperinflation at regular preset intervals: intermittent mandatory ventilation (IMV). The mechanical hyperinflations can gradually be reduced in frequency until weaning is complete. We have used IMV to facilitate weaning from mechanical ventilation in over 50 patients. The case histories of six of these patients, who failed to wean with conventional techniques, are presented in detail. Our experience suggests that IMV is more efficient, safer, more readily accepted by the patient and, therefore, preferable to conventional ventilatory and weaning methods.