PT  - JOURNAL ARTICLE
AU  - AJ Padkin
AU  - WJ Kinnear
TI  - Supplemental oxygen and nasal intermittent positive pressure ventilation
AID  - 10.1183/09031936.96.09040834
DP  - 1996 Apr 01
TA  - European Respiratory Journal
PG  - 834--836
VI  - 9
IP  - 4
4099  - http://erj.ersjournals.com/content/9/4/834.short
4100  - http://erj.ersjournals.com/content/9/4/834.full
SO  - Eur Respir J1996 Apr 01; 9
AB  - When supplementary oxygen is necessary with nasal intermittent positive pressure ventilation (NIPPV), the optimal route by which it should be added to the ventilator circuit is unknown. We investigated the oxygen concentration received when oxygen was supplied at flow rates between 0 and 6 L.min-1 into the proximal ventilator tubing or the nasal mask whilst patients were ventilated with air. Eleven patients with stable chronic hypercapnic respiratory failure were studied. A calibration curve was produced for each by supplying different known oxygen concentrations through a Monnal D or DCC ventilator and measuring the arterial oxygen saturations achieved. Oxygen was then supplied into the ventilator tubing or nasal mask and arterial saturation again measured. The oxygen concentration received was estimated using the calibration curve. Tracheal oxygen concentration throughout the respiratory cycle was studied in one patient when oxygen was supplied by both routes. Peak inspired oxygen concentration occurred at end-inspiration when oxygen was supplied into the ventilator tubing, but at mid-inspiration when supplied into the nasal mask. However, there was no significant difference between the two routes in the inspired oxygen concentration achieved at all flow rates: 1 L.min-1 supplied approximately 31% oxygen; 2 L.min-1 37%; 3 L.min-1 40%; and 4 L.min-1 44%. Flow rates above 4 L.min-1 had little additional effect. In conclusion, oxygen supplementation during nasal intermittent positive pressure ventilation can be provided into the ventilator tubing or the nasal mask with equal efficiency.