Effects of ventilatory strategy on arterial oxygenation and respiratory mechanics in overweight and obese patients undergoing posterior spine surgery

Kyung Mi Kim,Dongchul Lee,Hyun Jeong Kwak,Su Bin Kim,Jung Ju Choi,Wol Seon Jung

doi:10.1038/s41598-019-53194-2

Kyung Mi Kim, Dongchul Lee + Show 4 more

Open Access

https://doi.org/10.1038/s41598-019-53194-2

Copy DOI

Abstract

Prolonged inspiratory to expiratory (I:E) ratio ventilation may improve arterial oxygenation or gas exchange and respiratory mechanics in patients with obesity. We performed a randomised study to compare the effects of the conventional ratio ventilation (CRV) of 1:2 and the equal ratio ventilation (ERV) of 1:1 on arterial oxygenation and respiratory mechanics during spine surgery in overweight and obese patients. Fifty adult patients with a body mass index of ≥25 kg/m2 were randomly allocated to receive an I:E ratio either l:2 (CRV; n = 25) or 1:1 (ERV; n = 25). Arterial oxygenation and respiratory mechanics were recorded in the supine position, and at 30 minutes and 90 minutes after placement in the prone position. The changes in partial arterial oxygen pressure (PaO2) over time did not differ between the groups. The changes in partial arterial carbon dioxide pressure over time were significantly different between the two groups (P = 0.040). The changes in mean airway pressure (Pmean) over time were significantly different between the two groups (P = 0.044). Although ERV provided a significantly higher Pmean than CRV during surgery, the changes in PaO2 did not differ between the two groups.

Highlights

Prolonged inspiratory to expiratory (I:E) ratio ventilation may improve arterial oxygenation or gas exchange and respiratory mechanics in patients with obesity
This randomised study compared the conventional ratio ventilation (CRV) of 1:2 with the equal ratio ventilation (ERV) of 1:1 in terms of their effect on arterial oxygenation and respiratory mechanics during posterior lumbar spine surgery in overweight and obese patients placed in the prone position
In the ERV group, arterial pH was significantly lower during surgery (P < 0.001), and it was lower at 90 minutes (T90) after placement in the prone position than in the supine position (Tsupine) (P < 0.001)

Summary

Introduction

Prolonged inspiratory to expiratory (I:E) ratio ventilation may improve arterial oxygenation or gas exchange and respiratory mechanics in patients with obesity. We performed a randomised study to compare the effects of the conventional ratio ventilation (CRV) of 1:2 and the equal ratio ventilation (ERV) of 1:1 on arterial oxygenation and respiratory mechanics during spine surgery in overweight and obese patients. Prolonged inspiratory to expiratory (I:E) ratio ventilation, which is an effective ventilatory manoeuvre in obese patients undergoing laparoscopic bariatric surgery[12,13]; this technique improves gas exchange, arterial oxygenation, and respiratory mechanics in patients with acute respiratory distress syndrome or acute lung injury. We hypothesized that prolonged I:E ratio ventilation improves arterial oxygenation and respiratory mechanics in overweight and obese patients undergoing lumbar spine surgery. This randomised study compared the conventional ratio ventilation (CRV) of 1:2 with the equal ratio ventilation (ERV) of 1:1 in terms of their effect on arterial oxygenation and respiratory mechanics during posterior lumbar spine surgery in overweight and obese patients placed in the prone position

Objectives

Methods

Results

Conclusion