Larger tidal volume increases sevoflurane uptake in blood: a randomized clinical study
Author
Summary, in English
Background The rate of uptake of volatile anesthetics is dependent on alveolar concentration and ventilation, blood solubility and cardiac output. We wanted to determine whether increased tidal volume (V-T), with unchanged end-tidal carbon dioxide partial pressure (PETCO2), could affect the arterial concentration of sevoflurane. Methods Prospective, randomized, clinical study. ASA physical status 2 and II patients scheduled for elective surgery of the lower abdomen were randomly assigned to one of the two groups with 10 patients in each: one group with normal V-T (NVT) and one group with increased V-T (IVT) achieved by increasing the inspired plateau pressure 0.04 cmH(2)O/kg above the initial plateau pressure. A corrugated tube added extra apparatus dead space to maintain PETCO2 at 4.5 kPa. The respiratory rate was set at 15 min-1, and sevoflurane was delivered to the fresh gas by a vaporizer set at 3%. Arterial sevoflurane tensions (P(a)sevo), F(i)sevo, P(ET)sevo, PETCO2, PaCO2, V-T and airway pressure were measured. Results The two groups of patients were similar with regard to gender, age, weight, height and body mass index. The mean P(ET)sevo did not differ between the groups. Throughout the observation time, arterial sevoflurane tension (mean +/- SE) was significantly higher in the IVT group compared with the NVT group, e.g. 1.9 +/- 0.23 vs. 1.6 +/- 0.25 kPa after 60 min of anesthesia (P < 0.05). Conclusion Ventilation with larger tidal volumes with isocapnia maintained with added dead-space volume increases the tension of sevoflurane in arterial blood.
Publishing year
2010
Language
English
Pages
1111-1116
Publication/Series
Acta Anaesthesiologica Scandinavica
Volume
54
Issue
9
Links
Document type
Journal article
Publisher
Wiley-Blackwell
Topic
- Anesthesiology and Intensive Care
Status
Published
Research group
- Anaesthesiology and Intensive Care Medicine
ISBN/ISSN/Other
- ISSN: 0001-5172