[Changes of arterial oxygen tension in supine position during one-lung anesthesia].
BACKGROUND
One-lung ventilation during anesthesia (one-lung anesthesia) in patients under lateral decubitus position to help performing intra-thoracic surgical procedures was well known to have larger alveolar-to-arterial oxygen tension difference and lower arterial oxygen tension (PaO2) as compared to two-lung ventilation. In the present study, we investigate the changes of arterial oxygen tension in the supine position during one-lung anesthesia.


METHODS
Forty-two patients of palmar hyperhidrosis, ASA class I-II, scheduled to receive bilateral transthoracic endoscopic sympathectomy were studied. After anesthetic induction (fentanyl, thiopental, and succinylcholine), a 35 (for female) or 37 (for male) French left-sided Robertshaw double-lumen endobronchial tube was intubated. Anesthesia was maintained with isoflurane 1.0-1.5% and 50% O2-N2O. They were changed to isoflurane 1.5-2.0% and 100% O2 during one-lung ventilation. Once the surgical operation is completed, they were changed to 100% O2 and two-lung ventilation. Arterial blood gases were measured at 4 phases: 5 min after endobronchial intubation (two-lung ventilation), 5 min after left one-lung ventilation, 5 min after right one-lung ventilation, and 5 min after accomplishing operation (two-lung ventilation).


RESULTS
The results showed PaO2 were significantly lower in left and right one-lung ventilation with 100% O2 as compared with that obtained from two-lung ventilation with 50% O2 5 min after endobronchial intubation (p < 0.05). Furthermore, right one-lung ventilation had a lower PaO2 than left one-lung ventilation (p < 0.05).


CONCLUSIONS
We conclude that arterial oxygen tension can be safely maintained during one-lung anesthesia with pure oxygen in healthy patients lying in a supine position.
Day
Y B
YB
Department of Anesthesiology, Navy General Hospital, Tainan, Taiwan, R.O.C.
Lee
C G
CG
Tseng
C C
CC
Chiang
M H
MH
Chang
C L
CL
D000293:Adolescent; D000328:Adult; D000758:Anesthesia; D001158:Arteries; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D010100:Oxygen / Q000097:blood*; D011652:Pulmonary Circulation; D016683:Supine Position
D010100:Oxygen