Impact of intravenous infusion of lidocaine on intrapulmonary shunt and postoperative cognitive function in patients undergoing one-lung ventilation.

Background: Intravenous infusion of lidocaine as an anesthesia adjuvant can improve patient outcomes, but its impact on intrapulmonary shunt during one-lung ventilation (OLV) has not been clarified.

Objectives: To determine the effect of intravenous lidocaine infusion on intrapulmonary shunt during OLV and postoperative cognitive function in video-assisted thoracoscopic surgery (VATS).

Material and methods: Sixty patients who underwent OLV for thoracic surgery were randomized to receive intravenous infusion of lidocaine (lidocaine group, n = 30) or normal saline (control group, n = 30) for anesthesia induction. Arterial and venous blood gases were measured during two-lung ventilation and at 15 and 30 min after OLV (OLV + 15 and OLV + 30). The Mini-Mental State Examination was administered before the surgery and at postoperative 12 months to assess patient cognitive function.

Results: No significant difference was found in intrapulmonary shunt fraction (Qs/Qt) between the lidocaine group and the control group at OLV + 15 (p = 0.493) and OLV + 30 (p = 0.754). The lidocaine group used significantly lower doses of propofol and remifentanil compared to the control group (both p < 0.001). Furthermore, no significant difference was observed in the incidence of postoperative cognitive dysfunction between the lidocaine group and the control group at 1 year post-operation (3.3% vs 6.7%, p = 0.554).

Conclusions: Intravenous lidocaine administered in VATS had no significant impact on intrapulmonary shunt during OLV or postoperative cognitive function. However, it significantly reduced the doses of anesthetics used during the surgery.