Ventilation strategies with different inhaled Oxygen conceNTration during CardioPulmonary Bypass in cardiac surgery (VONTCPB): study protocol for a randomized controlled trial

Meng-Qiu Zhang,
Yu-Qi Liao,
Hong Yu,
Xue-Fei Li,
Liang Feng,
Xiao-Yun YangEmail author and
Hai YuEmail author

Trials201920:254

https://doi.org/10.1186/s13063-019-3335-2

Received: 11 September 2018
Accepted: 28 March 2019
Published: 3 May 2019

Open Peer Review reports

Abstract

Background

There is no consensus on the ventilation management during cardiopulmonary bypass (CPB), and the anesthesiologists or the surgeons usually ventilate the lungs with different ventilation strategies or keep them static. Better outcomes are more likely to occur when the ventilation is administered during CPB according to the existing literatures. However, the use of high fraction of inspired oxygen (FiO2) is debatable in cardiac surgery. And the potential effects of strategies combining low tidal volume (VT) ventilation with different FiO2 during CPB on postoperative pulmonary complications (PPCs) are unclear.

Design

The VONTCPB trial is a single-center, prospective, double-blinded, randomized, controlled trial. We are going to recruit total 420 elective cardiac surgery patients with median sternotomy under CPB, who will be equally randomized into three different ventilation strategy groups: NoV, LOV and HOV. (1) The NoV group receives no mechanical ventilation during CPB; (2) the LOV group receives a low VT of 3-4 ml/kg of ideal body weight (IBW) with the respiratory rate (RR) of 10–12 acts/min, and the positive end-expiratory pressure (PEEP) of 5–8 cmH2O during CPB; the FiO2 is 30%; (3) the HOV group receives a low VT of 3-4 ml/kg of IBW with the RR of 10–12 acts/min, and the PEEP of 5–8 cmH2O during CPB; the FiO2 is 80%. The primary endpoints are the incidence of the composite of PPCs and the PPCs score. The secondary endpoints refer to the incidence of the oxygenation index (PaO2/FiO2 ratio) < 300 mmHg at three time points (the moment arriving in the ICU, 6 and 12 h after arrival in the ICU), the surgical incision healing grade, the intubation time, the stay of ICU, the length of hospital stay, and mortality at 30 days after the surgery.

Discussion

The VONTCPB trial is the first study to assess the effects of strategies combining low tidal volume (VT) ventilation with different FiO2 during CPB on patients’ outcomes.