To examine the safety, feasibility and utility of combined cutaneous carbon dioxide tension (PcCO2) and oximetry monitoring to re-titrate the non-invasive positive pressure ventilation settings in patients with chronic hypercapnic respiratory failure due to hypoventilation.
12 patients with chronic hypercapnic respiratory failure underwent complete polysomnography and combined oximetry and PcCO2 measurement (Sentec AG, Switzerland) on the ear lobe. non-invasive positive pressure ventilation pressures were adjusted with the aim of normalizing PcCO2 or reducing it by 10 to 15 mm Hg. Sensor drift for PcCO2 measurement was calculated to reduce the discrepancy between PcCO2 and awake arterial carbon dioxide tension. Epworth sleepiness score and patient satisfaction with home ventilation was charted on a 10 centimeter visual analogue scale before and after the study.
Mean baseline PcCO2 was 45.4 ± 6.5 mm Hg and drift corrected awake PcCO2 was 45.1 ± 8.3 mm Hg. IPAP pressures were changed in nine patients and EPAP in eight patients. Epworth sleepiness score before and after the study showed no change in five patients, mild improvement in six patients and mild deterioration in one patient. Seven patients had a mild increase and five patients a mild decrease in their visual analogue scale score at follow up.
Combined continuous PcCO2 and oximetry monitoring is feasible and permits the optimization of non-invasive positive pressure ventilation settings in patients with chronic hypercapnic respiratory failure due to hypoventilation. Continuous PcCO2 monitoring might serve as an important additional tool to complement diurnal arterial carbon dioxide tension values.
A titration study with continuous PcCO2 measurement in patients receiving non-invasive positive pressure ventilation can be helpful to optimize the ventilator settings.
Prashant Chhajed, None.