Download this document in PDF format. PDF reading software can be found here.

Oxygen Therapy During RTube™ Sampling

Purpose: To provide the same or higher concentration of oxygen to the patient during breath condensate sampling.

Equipment List

1. RTube
2. 15 mm I.D./22 mm O.D. multi adaptor
3. 6 inches of corrugated tubing
4. 22 mm I.D./22 mm O.D. oxygen attachment adapter
5. 6 ft. of star lumen oxygen tubing
6. Oxygen flow meter 0-15 l/min
7. Oxygen source

Procedure

1. 1. In order to provide the same FIO2 or higher you will need to determine the patient's approximate minute ventilation and current FIO2. Most patients' spontaneous tidal volumes are 5-7 cc/kg of ideal body weight
2. Add the 6 inch reservoir to the RTube by using the 15 mm I.D./ 22 mm O.D. multi adapter and the oxygen attachment adapter.
3. Place patient on pulse oximeter.
4. Use the below FIO2 estimation equation to determine the approximate oxygen flow required to meet the patient's FIO2 demand.
   
   
   O2 represents the flow in liter per minute of 100% oxygen provided to the RTube. The V insp. is the patient's average inspiratory flow rate, simply multiply the patient's minute ventilation by the sum of the I:E ratio parts (I:E ratio being observed or estimated). As an example:
             VT = 200 ml
             Respiratory rate = 16
             Min. ventilation = 3.2 liters/min
             Observed I:E ratio = 1:2
             Sum of I:E parts = 3
             Est. average insp. flow = 9.6 liters/min
   
   Now assume that we are going to add 2 L/min to the RTube with the above ventilator parameter.
   
   
   Estimated FIO2 is .37
5. Connect the modified RTube to the oxygen flowmeter and titrate to the appropriate liter flow for estimated FIO2 delivery.
6. Remove patient oxygen source and have them breath through the modified RTube normally.
7. Monitor SPO2 and adjust oxygen flow to keep within acceptable range throughout sampling.