Physiological effects of translaryngeal open ventilation in patients with restrictive respiratory disorders

Objective: To compare the efficacy of pressure-controlled ventilation (PCV) delivered through a conventional endotracheal tube with the same ventilatory mode using a small-size tube with the cuff left deflated (translaryngeal open ventilation: TLOV). Setting: A medical-surgical intensive care unit (ICU). Design: Prospective physiological study. Patients: Thirteen consecutive patients with restrictive neuromuscular and thoracic respiratory disorders ventilated in pressure-controlled mode. Interventions: The standard tube was removed and a microlaryngeal tube (i.d. 4 mm, o.d. 6 mm, length 380 mm) was inserted with the cuff left deflated. PCV was increased to match the tracheal pressure measured during conventional ventilation. Arterial blood gases were measured before, 1 h and 20 h after initiating TLOV. A patient comfort score was measured by a visual analogue scale during conventional ventilation and 20 h after initiating TLOV (0= very bad, 1= bad, 2= quite bad, 3= sufficient, 4= good, and 5= very good). Results: Inspiratory pressure was significantly increased from 16±5 cmH₂O to 68±13 cmH₂O after 1 h and to 65±12 cmH₂O after 20 h to match the tracheal pressure measured during conventional ventilation (CV) (p<0.005). No statistically significant differences were found in arterial blood gases and patient's respiratory rate before and after 1 and 20 h of TLOV. The comfort score was 1.3±0.4 and 3.6±0.4 during CV and TLOV, respectively, on a scale from 0 to 5 (p±0.002). Conclusion: This study indicates that, in selected patients, TLOV was as efficient as conventional PCV.