The use of continuous Flow Ventilatory Support for Hypercapnic Respiratory Failure

Abstract

Our aim was to assess the effectivity of continuous flow ventilatory support (CFVS) in those COPD patients undergoing cardiac surgery who developed hypercapnic respiratory failure.Materials and methods. CFVS was applied in 11 COPD (Stage 2.55±0.52 on average) patients undergoing cardiac surgery, after weaning from «conventional» pressure controlled (PCV) or pressure support ventilation (PSV) mode. All of these patients had hypercapnea with respiratory failure that has been manifested after 15±10 hours after postoperative weaning from ventilator. CFVS was applied using nasotracheal catheter (diameter 5–6 mm) with average inspiratory flow Qin = 26±2,3 l/min while using FiO2 of 0.3–0.35.Results. Only one out of 11 patients failed to recover from hypercapnic respiratory failure using CFVS and had to be intubated instead. Spontaneous ventilation frequency was gradually decreasing from 24.8±3.6 breaths/min to 16±2 breaths/min after initiation of CFVS (P<0.01). Average value of PaO2 before CFVS was 59±7.5 mmHg and rose to 99.6±4.5 mmHg just before CFVS was terminated (P<0.01). PaCO2 before CFVS was measured to be 73.2±7.5 mmHg and dropped to 45.7±4.3 mmHg (P<0.01). CO2 drop was fast in the first 18 hours from CFVS application. Average time for application of CFVS was 3.09±0.9 day.Conclusion. CFVS is an effective and minimally invasive mode of ventilation support that can be used in patients suffering from hypercapnic respiratory failure to avoid the need to intubate trachea and connect the patient to conventional ventilator.

Keywords

• ventilatory support
• weaning from mechanical ventilation
• continuous flow ventilation support