Lung-protective ventilation suppresses systemic and hepatic vein levels of cell-free DNA in porcine experimental post-operative sepsis

Abstract

Background: Plasma levels of cell-free DNA (cf-DNA) are known to be elevated in sepsis and high levels are associated with a poor prognosis. Mechanical ventilation affects systemic inflammation in which lung-protective ventilation attenuates the inflammatory response. The aim was to study the effect of a lung protective ventilator regime on arterial and organ-specific venous blood as well as on trans-organ differences in cf-DNA levels in a porcine post-operative sepsis model. Method: One group of anaesthetised, domestic-breed, 9-12 weeks old, pigs were ventilated with protective ventilation (V T 6 mL x kg − 1 , PEEP 10 cmH 2 O) n = 20. Another group, ventilated with a medium high tidal volume and lower PEEP, served as a control group (V T 10 mL x kg − 1 , PEEP 5 cm H 2 O) n = 10. Blood samples were taken from four sources: artery, hepatic vein, portal vein and, jugular bulb. A continuous endotoxin infusion at 0.25 μg x kg − 1 x h − 1 for 5 h was started following 2 h of laparotomy, which simulated a surgical procedure. Inflammatory cytokines and cf-DNA in plasma were analysed and trans-organ differences calculated. Results: The protective ventilation group had lower levels of cf-DNA in arterial (p = 0.02) and hepatic venous blood (p = 0.03) compared with the controls. Transhepatic differences in cf-DNA were lower in the protective group, compared with the controls (p = 0.03). No differences between the groups were noted as regards the transcerebral, transsplanchnic or the transpulmonary cf-DNA differences. Conclusions: Protective ventilation suppresses arterial levels of cf-DNA. The liver seems to be a net contributor to the systemic cf-DNA levels, but this effect is attenuated by protective ventilation.

Effect of Lung Protective Ventilation Combined With Flurbiprofen Axetil on Immune Function During Thoracoscopic Radical Resection of Lung Cancer

“…Previous studies have pointed out that when tidal volume is 15 ml/kg, end-expiratory lung volume can be improved and intraoperative atelectasis can be relieved ( 11 ). In addition, if there are no contraindications, the use of positive end-expiratory pressure and lung recruitment can also help prevent end-expiratory lung volume loss and small airway closure during anesthesia ( 12 ). Although 10 ml/kg tidal volume was mostly used in clinical practice in the past, anesthesiologists would reduce tidal volume during single ventilation.…”