Effects of phenylephrine and norepinephrine with restrictive infusion on oxygenation during one-lung ventilation for lung surgery: a randomized controlled trial.
Jiaxin Li, Xiangjie Liu, Longhe Xu et al.
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In 30 seconds
This randomized controlled trial compared phenylephrine and norepinephrine, each combined with restrictive infusion, against control during thoracoscopic one-lung ventilation in 90 patients undergoing lung surgery. At 45 minutes of one-lung ventilation, the phenylephrine group had significantly higher arterial oxygen partial pressure (PaO₂) and lower intrapulmonary shunt fraction (Qs/Qt) than either the norepinephrine or control group; norepinephrine did not differ significantly from control. Phenylephrine was also associated with higher lung-tissue endothelin and COX-2 levels. The authors suggest these changes may enhance hypoxic pulmonary vasoconstriction.
Key findings
- At 45 minutes of one-lung ventilation, phenylephrine produced higher PaO₂ and lower Qs/Qt than norepinephrine or control (all p < 0.05).
- At 45 minutes, PaO₂ and Qs/Qt did not differ significantly between the norepinephrine and control groups (all p > 0.05).
- Lung-tissue endothelin and COX-2 levels were higher with phenylephrine than with norepinephrine or control (all p < 0.05).
Why it matters
Oxygenation can deteriorate during one-lung ventilation, and the trial suggests that the choice of vasopressor alongside restrictive infusion may affect oxygenation and shunt. The accompanying tissue-marker findings offer a possible mechanism involving hypoxic pulmonary vasoconstriction, although they do not establish that mechanism as causal.
What to keep in mind
The abstract reports no numerical effect sizes for the oxygenation outcomes, limiting assessment of the magnitude of the observed differences.