STUDY OBJECTIVEPostoperative pulmonary complications (PPCs), the predominant complications following lung surgery, are closely associated with intraoperative fluid therapy. This study investigates whether continuous low-dose norepinephrine infusion combined with goal-directed fluid therapy (GDFT) reduced the risk of PPCs after lung surgery relative to either GDFT alone or standard fluid treatment.DESIGNA prospective, randomized controlled trial.SETTINGThe First Affiliated Hospital of Anhui Medical University, Anhui, China.PATIENTSThe study included 184 patients undergoing elective thoracoscopic lung resection surgery.INTERVENTIONSPatients were randomized into three groups based on different fluid treatment regimens: Group C received standard fluid treatment, Group G received GDFT, and Group N received continuous low-dose norepinephrine infusion combined with GDFT.MEASUREMENTSThe primary outcome was the incidence of PPCs, including respiratory infection, atelectasis, pneumothorax, pleural empyema, respiratory failure, pulmonary embolism and bronchopleural fistula, during the postoperative hospital stay. Secondary outcomes were hemodynamic variables and arterial blood gases. Additional recorded parameters included other postoperative complications such as bleeding, postoperative re-intubation, re-hospitalization within 30 days, and the length of hospital stay.MAIN RESULTSGroup N showed a significantly lower PPCs incidence during hospitalization compared to Group C (11.5 % vs 27.9 %; odds ratio, 2.98; 95 % confidence interval, 1.17-8.31; P = 0.023). No significant difference in PPCs was found between Group N and Group G (11.5 % vs 14.5 %; odds ratio, 1.31; 95 % confidence interval, 0.46-3.91; P = 0.616). Additionally, there were no significant differences among the three groups in the components of PPCs. Group N showed higher mean arterial pressure and stroke volume index intraoperatively compared to Group C.CONCLUSIONSContinuous low-dose norepinephrine infusion combined with GDFT reduced PPCs incidence in elective lung surgery patients compared with standard fluid management, but showed no difference compared to GDFT alone.CLINICAL TRIAL REGISTRATIONChiCTR2200064081.