Volume-controlled ventilation versus pressure-controlled ventilation during spine surgery in the prone position: A meta-analysis

Abstract

Background: Many studies have investigated a comparison of the potency and safety of PCV versus VCV modes in spinal surgery in prone position. However, controversy about the maximal benefits of which ventilation modes remains. The main purpose of this meta-analysis was to investigate which one is the optimal ventilation for surgery patients undergoing spine surgery in prone position between the two ventilation modes as PCV and VCV.

Methods: We conducted a comprehensive search of PubMed, Embase, Web of Science, the Cochrane Library, and Google Scholar for potentially eligible articles. The continuous outcomes were analyzed using the mean difference and the associated 95% confidence interval. Meta-analysis was performed using Review Manager 5.4 software.

Results: Our meta-analysis included 8 RCTs involving a total of 454 patients between 2012 and 2020. The results demonstrated that IOB, Ppeak and CVP for VCV are significantly superior to PCV in spinal surgery in prone position. And PCV had higher Cdyn and PaO₂/FiO₂ than VCV. But there was no significant difference between PCV and VCV in terms of POB, Hb, HCT, HR and MAP.

Conclusions: The PCV mode displayed a more satisfying effect than VCV mode. Compared to VCV mode in same preset of tidal volume, the patients with PCV mode in prone position demonstrated less IOB, lower Ppeak and CVP, and higher PaO₂/FiO₂ in spinal surgery. However, there is no obvious difference between PCV and VCV in terms of hemodynamics variables (HR and MAP).

Keywords: ASA, American Society of Anesthesiologists; BMI, body mass index; CVP, central venous pressure; Cdyn, dynamic compliance; HCT, hematocrit; HR, heart rates; Hb, hemoglobin; IOB, intra-operation blood loss; MAP, mean arterial pressure; MD, mean difference; Meta-analysis; NP, not provided; PCV, pressure controlled ventilation; PEEP, Positive End Expiratory Pressure; PILF, Posterior Lumbar Interbody Fusion; POB, post-operation blood loss; Pressure-controlled ventilation; Prone position; RCT, randomized controlled trial; Randomized controlled trials; Spine surgery; VCV, volume controlled ventilation; VT, tidal volume; Volume-controlled ventilation.

Fig. 1

Flow diagram of the study selection process for the meta-analysis.

Fig. 2

Risk of bias summary.

Fig. 3

Forest plots and meta-analyses. a: intra-operation blood loss; b: sensitivity analysis of intra-operation blood loss. [95% CI: 95% confidence intervals, df: degrees of freedom, Random: random effects model, Fixed: fixed effects model, IV: inverse variance,]; c. Forest plots of the post-operation blood loss. [95% CI: 95% confidence intervals, df: degrees of freedom, Fixed: fixed effects model, IV: inverse variance,].

Fig. 4a

Forest plots of the Hemoglobin. [95% CI: 95% confidence intervals, df: degrees of freedom, Fixed: fixed effects model, IV: inverse variance,]; 4b. Forest plots of the Hematocrit. [95% CI: 95% confidence intervals, df: degrees of freedom, Fixed: fixed effects model, IV: inverse variance,].

Fig. 5a

Forest plots of the Ppeak. [95% CI: 95% confidence intervals, df: degrees of freedom, Random: random effects model, IV: inverse variance,]; 5b, c. Forest plots and meta-analyses. b: CVP; c: sensitivity analysis of CVP. [95% CI: 95% confidence intervals, df: degrees of freedom, Random: random effects model, Fixed: fixed effects model, IV: inverse variance,].

Fig. 6a

Forest plots of the heart rates. [95% CI: 95% confidence intervals, df: degrees of freedom, Fixed: fixed effects model, IV: inverse variance,]; 6b. Forest plots of the mean arterial pressure. [95% CI: 95% confidence intervals, df: degrees of freedom, Random: random effects model, IV: inverse variance,].

Fig. 7a

Forest plots of the dynamic compliance. [95% CI: 95% confidence intervals, df: degrees of freedom, Fixed: fixed effects model, IV: inverse variance,]; 7b. Forest plots of the PaO₂/FiO₂. [95% CI: 95% confidence intervals, df: degrees of freedom, Fixed: fixed effects model, IV: inverse variance,].