Comparison of volume-controlled and pressure-controlled ventilation using a laryngeal mask airway during gynecological laparoscopy

Abstract

Background: Several publications have reported the successful, safe use of Laryngeal Mask Airway (LMA)-Classic devices in patients undergoing laparoscopic surgery. However, there have been no studies that have examined the application of volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV) using a LMA during gynecological laparoscopy. The aim of this study is to compare how the VCV and PCV modes and using a LMA affect the pulmonary mechanics, the gas exchange and the cardiovascular responses in patients who are undergoing gynecological laparoscopy.

Methods: Sixty female patients were randomly allocated to one of two groups, (the VCV or PCV groups). In the VCV group, baseline ventilation of the lung was performed with volume-controlled ventilation and a tidal volume of 10 ml/kg ideal body weight (IBW). In the PCV group, baseline ventilation of the lung using pressure-controlled ventilation was initiated with a peak airway pressure that provided a tidal volume of 10 ml/kg IBW and an upper limit of 35 cmH(2)O. The end-tidal CO(2), the peak airway pressures (P(peak)), the compliance, the airway resistance and the arterial oxygen saturation were recorded at T1: 5 minutes after insertion of the laryngeal airway, and at T2 and T3: 5 and 15 minutes, respectively, after CO(2) insufflation.

Results: The P(peak) at 5 minutes and 15 minutes after CO(2) insufflation were significantly increased compared to the baseline values in both groups. Also, at 5 minutes and 15 minutes after CO(2) insufflation, there were significant differences of the P(peak) between the two groups. The compliance decreased in both groups after creating the pneumopertoneim (P < 0.05).

Conclusions: Our results demonstrate that PCV may be an effective method of ventilation during gynecological laparoscopy, and it ensures oxygenation while minimizing the increases of the peak airway pressure after CO(2) insufflation.

Keywords: LMA; Lapraroscopic surgery; Pressure-controlled ventilation; Volume-controlled ventilation.

Fig. 1

Changes of compliance during anesthesia. T1: 5 minutes after insertion of the laryngeal airway, T2: 5 minutes after CO₂ insufflation, T3: 15 minutes after CO₂ insufflation, VCV: volume-controlled ventillation, PCV: pressure-controlled ventilation. ^*P < 0.01 compared with the T1 value.