Effect of inspiratory oxygen fraction during driving pressure-guided ventilation strategy on pulmonary complications following open abdominal surgery: A randomized controlled trial

Study objective

The aim of the present study was to determine the effect of 30 % fraction of inspired oxygen (FIO₂) compared with 80 % FIO₂ in the context of driving pressure-guided ventilation strategy on pulmonary complications following open abdominal surgery.

Design

A single-center, prospective, randomized controlled trial.

Setting

Tertiary university hospital in China.

Patients

514 adult patients, ASA I-III and scheduled for major open abdominal surgery under general anesthesia.

Interventions

Patients were randomly assigned to receive either 30 % or 80 % FIO₂ during the intraoperative period. All patients received driving pressure-guided ventilation strategy, including low tidal volume and individualized PEEP set at lowest driving pressure.

Measurements

The primary outcome was the incidence of a composite of pulmonary complications within the 7 days postoperatively. The severity of pulmonary complications, extrapulmonary complications, and other secondary outcomes were also assessed.

Main results

Of 1553 patients assessed for eligibility, 514 patients were randomly assigned and analyzed with intention-to-treat principle. Patients receiving 30 % FIO₂ had a significantly lower incidence of postoperative pulmonary complications (PPCs) compared to those receiving 80 % FIO₂ (46.3 %vs. 64.6 %; RR, 0.72; 95 % CI, 0.61–0.84; P < 0.001). The severity score of PPCs was significantly reduced in the 30 % FIO₂ group compared with that in the 80 % FIO₂ group within the 7 postoperative days (P < 0.001). Dynamic compliance was significantly greater in 30 % FIO₂ group at the end of surgery (56 [48–66] vs. 53 [46–62], P = 0.027). More patients in the 80 % FIO₂ group developed oxygen desaturation (SpO₂ < 94 %) on air intake during PACU stay (18.5 %vs. 30.4 %; RR, 0.61; 95 % CI, 0.44–0.84; P = 0.002; 30 % FIO₂ group vs.80 % FIO₂ group).

Conclusions

In patients undergoing open abdominal surgery, using a 30 % FIO₂, compared with 80 % FIO₂, in context of driving pressure-guided ventilation strategy, intraoperatively reduced the incidence and severity of pulmonary complications within the first 7 postoperative days.