Is it safe for patients with chronic hypercapnic respiratory failure undergoing home noninvasive ventilation to discontinue ventilation briefly?

Study objectives: A brief discontinuation (< 1 week) of long-term ventilati on may be necessary in patients who are not totally ventilator-dependent in cases of technical problems, intolerable nasal irritation, upper airway co ngestion, or travel. We examined the incidence, timing, and causes of possi ble clinical deterioration after a brief withdrawal of ventilation in patie nts with chronic respiratory failure (CRF) who were well-established on lon g-term noninvasive mechanical ventilation (NIMV). Study design: Prospective clinical study. Patients: Eleven inpatients in clinically stable condition (COPD, 6 patient s; and restrictive thoracic disease [RTD], 5 patients) who had severe CRF ( Paco(2), > 50 mm Hg) and had been receiving NIMV for (mean +/- SD) 19.3 +/- 5.3 months were enrolled. Interventions and measurements: Arterial blood gas (ABG) levels, maximal in spiratory pressure (PImax), breathing pattern, dyspnea rating, and life sym ptoms (measured by a questionnaire) were recorded daily after NIMV withdraw al for 6 days or until the patients showed clinical and/or ABG level deteri oration, Pulmonary function tests were pet-formed and neuromuscular drive w as measured at the beginning and the end of the study. Results: Five of the 11 patients (45.4%) [COPD, 3 patients; and RTD, 2 pati ents] were reconnected to a ventilator before the scheduled time because of ABG level deterioration. Despite these changes, none of the patients repor ted severe worsening of symptoms or other medical complications. The patien ts whose ABG levels worsened had statistically significant decreases in tid al volume and PImax, suggesting that the development of alveolar hypoventil ation was related to respiratory muscle weakness. Conclusions: A brief discontinuation of NIMV in patients who were affected by chronic hypercapnic respiratory failure and were well-established on NIM V is associated with a relatively high incidence of ABG level worsening due to the development of alveolar hypoventilation. If NIMV must be briefly in terrupted for clinical reasons, the patient should be monitored closely for abrupt worsening, and prompt technical intervention should be provided if a ventilator fails.