Epidural block does not worsen oxygenation during one-lung ventilation for lung resections under isoflurane/nitrous oxide anaesthesia.
OBJECTIVE
The aim of this prospective, randomized, controlled clinical study was to evaluate the effects of thoracic epidural anaesthesia combined with isoflurane/nitrous oxide anaesthesia on intraoperative oxygenation during one-lung ventilation for lung resections.


METHODS
Forty patients were randomly allocated to receive general anaesthesia maintained with isoflurane/nitrous oxide (group General, n = 20) or the same anaesthetic combined with thoracic epidural anaesthesia (group Integrated, n = 20). All patients were mechanically ventilated with the same settings (FiO2 = 0.5; VT = 9 mL kg(-1); inspiratory: expiratory time = 1:1; inspiratory pause = 10%). Effects on oxygenation were evaluated by determining the changes in PaO2/FiO2 ratio at 10, 30, 45 and 60 min of one-lung ventilation as compared to values obtained after induction of anaesthesia (supine, two-lung ventilation).


RESULTS
The PaO2/FiO2 ratio was decreased in both groups during one-lung ventilation until the end of surgery. No differences were found at any observation time between the groups. Ventilation with 100% oxygen because of SpO2 decrease <92% was required in nine patients of group General (45%) and in eight patients of group Integrated (40%) (P = 0.64). Manual re-inflation of the operated lung was required in one patient of group General only (P = 0.99). Heart rate was lower in group Integrated than in group General throughout the study. No differences between the two groups in mean arterial pressure were observed.


CONCLUSIONS
Adding a thoracic epidural block to isoflurane/nitrous oxide anaesthesia during one-lung ventilation for lung resections does not result in clinically relevant detrimental effects on intraoperative oxygenation.
Casati
A
A
University of Parma, Department of Anaesthesiology and Pain Therapy, Parma, Italy. acasati@ao.pr.it
Mascotto
G
G
Iemi
K
K
Nzepa-Batonga
J
J
De Luca
M
M
D000767:Anesthesia, Epidural / Q000009:adverse effects / Q000379:methods*; D000768:Anesthesia, General / Q000379:methods; D019162:Anesthetics, Combined / Q000627:therapeutic use; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D001784:Blood Gas Analysis / Q000379:methods; D005260:Female; D006801:Humans; D007530:Isoflurane; D008168:Lung / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D009609:Nitrous Oxide; D010100:Oxygen / Q000097:blood*; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000379:methods*; D012129:Respiratory Function Tests / Q000379:methods; D019616:Thoracic Surgical Procedures; D013997:Time Factors
D019162:Anesthetics, Combined; D018685:Anesthetics, Inhalation; D007530:Isoflurane; D009609:Nitrous Oxide; D010100:Oxygen