Objective   To investigate the effect of therapeutic hypercapnia on the early inflammatory factors after ischemia-reperfusion of lung transplantation.

  Method   Seventy-two male Wistar rats were randomly divided into model group (n=36) and therapy group (n=36). Rats on the baseline in model group and therapy group were ventilated with 50% N₂ and 50% O₂. Rats in model group were continuously ventilated with 50% N₂ and 50% O₂ after successful transplantation. Rats in therapy group were ventilated with mixed gases after successful transplantation, which included 50% O₂, 8% CO₂, and 42% N₂ to keep arterial partial pressure of carbon dioxide(PaCO₂) in the range of 80~100 mmHg(10 mmHg=1.33 kPa). The mean arterial pressure (MAP)、PaCO₂ and arterial partial pressure of oxygen (PaO₂) of recipient rats were recorded as baseline value after mechanical ventilation for 1 minute. Then the data were recorded once every 30 minutes during reperfusion period until the end. The inferior lobes of left lung sample were taken at 1, 2,4 h after reperfusion respectively. The levels of tumor necrosis factor(TNF)-α and interleukin(IL)-1β in lung tissues were measured by enzyme-linked immunosorbent assay.

  Result   Compared with model group, MAP and PaO₂ were significantly higher in therapy group at different time points after reperfusion (all in P<0.05). Compared with model group, the levels of TNF-α and IL-1β of transplant lung tissues were significantly lower in therapy group at different time points after reperfusion(all in P<0.05).

  Conclusion   The therapeutic hypercapnia plays an inhibitive role on the release of early inflammatory factors after the ischemia-reperfusion injury of lung transplantation.