Partial pressure of oxygen and partial pressure of carbon dioxide of perfluorocarbon liquid during partial liquid ventilation: their regional difference and their dependence on tidal volume and positive end-expiratory pressure level.
OBJECTIVE
To investigate the regional partial pressure of oxygen (PO2) and partial pressure of carbon dioxide (PCO2) of the perfluorocarbon liquid (PpfcO2, PpfcCO2) during partial liquid ventilation (PLV).


METHODS
Prospective, controlled study.


METHODS
A research laboratory at a university medical center.


METHODS
Thirteen Japanese white rabbits.


METHODS
After the tracheostomy, PLV was started with perflubron (15 ml/kg) following saline lung lavage. Fractional inspired oxygen (FIO2) was 1.0, respiratory rate was 30 bpm and tidal volume (VT) was 30 ml. Two epidural catheters (18 gauge) were inserted from the rubber diaphragm interposed in the respiratory circuit to sample perflubron. One catheter was inserted into the left lower lobe bronchus and placed at 5-6 cm distal from the carina (DISTAL). The other one was inserted at the tip of the endotracheal tube (PROXIMAL). Then the effect of the larger VT (50 ml) or positive end-expiratory pressure (PEEP; 10 cmH2O) to the gas tension in perflubron was examined.


RESULTS
(1) In the lower VT (30 ml) with 0 cmH20 PEEP, DISTAL PpfcO2 was significantly lower than PROXIMAL PpfcO2 (265 72 vs 386 +/- 47 mmHg, p < 0.0001), and DISTAL PpfcCO2 was significantly higher than PROXIMAL PpfcCO2 (51.1 +/- 14.4 vs 42.4 +/- 11.8 mmHg (p = 0.0007)), (2) the higher VT setting increased PpfcO2 (p = 0.0001) and decreased PpfcCO2 (p < 0.0001), although the gas tension gradient was significant, (3) 10 cmH2O PEEP increased PpfcO2 (p = 0.0004) and decreased PpfcCO2 (p = 0.0089) in the DISTAL sample.


CONCLUSIONS
There was a difference in gas tension in perflubron between the central airway and the peripheral dependent lung region, and gas tension in perflubron was affected by the VT and the PEEP level.
Uchida
T
T
Department of Anesthesiology and Critical Care Medicine, Tokyo Medical and Dental University, School of Medicine, Japan. uchida.mane@tmd.ac.jp
Yokoyama
K
K
Nakazawa
K
K
Makita
K
K
D000704:Analysis of Variance; D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism*; D005466:Fluorocarbons / Q000494:pharmacology*; D006439:Hemodynamics; D021061:Liquid Ventilation; D010100:Oxygen / Q000378:metabolism*; D010313:Partial Pressure; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D011817:Rabbits; D013990:Tidal Volume
D005466:Fluorocarbons; D002245:Carbon Dioxide; D010100:Oxygen