Newly Published
Perioperative Medicine  |   August 2017
Effect of Bronchoconstriction-induced Ventilation–Perfusion Mismatch on Uptake and Elimination of Isoflurane and Desflurane
Author Notes
  • From the Hedenstierna Laboratory, Department of Surgical Sciences (M.K., A.K., J.B.B., A.L., T.S.), and Clinical Physiology, Department of Medical Sciences (G.H.), Uppsala University, Uppsala, Sweden; Department of Anesthesiology and Intensive Care Medicine, Otto von Guericke University Magdeburg, Magdeburg, Germany (M.K., A.K., T.H., T.S.); Oscillogy LLC, Pittsburgh, Pennsylvania (J.E.B.); and Department of Anesthesiology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (J.E.B.).
  • Part of the work presented in this article has been presented by M.K., A.K., and T.S. at the American Society of Anesthesiologists’ 2016 Annual Meeting in Chicago, Illinois, October 22 to 26, 2016. M.K. and A.K. contributed equally to this article.
    Part of the work presented in this article has been presented by M.K., A.K., and T.S. at the American Society of Anesthesiologists’ 2016 Annual Meeting in Chicago, Illinois, October 22 to 26, 2016. M.K. and A.K. contributed equally to this article.×
  • Submitted for publication August 19, 2016. Accepted for publication July 25, 2017.
    Submitted for publication August 19, 2016. Accepted for publication July 25, 2017.×
  • Acknowledgments: The authors express their special gratitude to Agneta Ronéus, Karin Fagerbrink, Annelie Ryden, and Maria Svaelas (Hedenstierna Laboratory, Uppsala University, Uppsala, Sweden) for their help and support during the experiment. Their work and their assistance in instrumentation and monitoring of the animals, as well as blood sampling and data recording, are greatly appreciated. The authors especially acknowledge the work of Eva-Maria Hedin (Hedenstierna Laboratory, Uppsala University, Uppsala, Sweden), who performed the multiple inert gas elimination technique measurements.
    Acknowledgments: The authors express their special gratitude to Agneta Ronéus, Karin Fagerbrink, Annelie Ryden, and Maria Svaelas (Hedenstierna Laboratory, Uppsala University, Uppsala, Sweden) for their help and support during the experiment. Their work and their assistance in instrumentation and monitoring of the animals, as well as blood sampling and data recording, are greatly appreciated. The authors especially acknowledge the work of Eva-Maria Hedin (Hedenstierna Laboratory, Uppsala University, Uppsala, Sweden), who performed the multiple inert gas elimination technique measurements.×
  • Research Support: Supported by the Swedish Research Council (X2015-99x-22731-01-04; Stockholm, Sweden), the Swedish Heart and Lung Fund (Stockholm, Sweden), and institutional sources of Uppsala University (Uppsala, Sweden) and Otto von Guericke University Magdeburg (Magdeburg, Germany).
    Research Support: Supported by the Swedish Research Council (X2015-99x-22731-01-04; Stockholm, Sweden), the Swedish Heart and Lung Fund (Stockholm, Sweden), and institutional sources of Uppsala University (Uppsala, Sweden) and Otto von Guericke University Magdeburg (Magdeburg, Germany).×
  • Competing Interests: Dr. Baumgardner is president of Oscillogy LLC (Pittsburgh, Pennsylvania), the manufacturer of the multiple inert gas elimination technique by micropore membrane inlet mass spectrometry system. The other authors declare no competing interests.
    Competing Interests: Dr. Baumgardner is president of Oscillogy LLC (Pittsburgh, Pennsylvania), the manufacturer of the multiple inert gas elimination technique by micropore membrane inlet mass spectrometry system. The other authors declare no competing interests.×
  • Correspondence: Address correspondence to Dr. Schilling: Department of Anesthesiology and Intensive Care Medicine, Otto-von-Guericke-University, Leipziger Strasse 44, D-39120 Magdeburg, Germany. Thomas.Schilling@med.ovgu.de. Information on purchasing reprints may be found at www.anesthesiology.org or on the masthead page at the beginning of this issue. Anesthesiology’s articles are made freely accessible to all readers, for personal use only, 6 months from the cover date of the issue.
Article Information
Perioperative Medicine / Endocrine and Metabolic Systems / Pharmacology / Respiratory System
Perioperative Medicine   |   August 2017
Effect of Bronchoconstriction-induced Ventilation–Perfusion Mismatch on Uptake and Elimination of Isoflurane and Desflurane
Anesthesiology Newly Published on August 31, 2017. doi:10.1097/ALN.0000000000001847
Anesthesiology Newly Published on August 31, 2017. doi:10.1097/ALN.0000000000001847
Abstract

Background: Increasing numbers of patients with obstructive lung diseases need anesthesia for surgery. These conditions are associated with pulmonary ventilation/perfusion (VA/Q) mismatch affecting kinetics of volatile anesthetics. Pure shunt might delay uptake of less soluble anesthetic agents but other forms of VA/Q scatter have not yet been examined. Volatile anesthetics with higher blood solubility would be less affected by VA/Q mismatch. We therefore compared uptake and elimination of higher soluble isoflurane and less soluble desflurane in a piglet model.

Methods: Juvenile piglets (26.7 ± 1.5 kg) received either isoflurane (n = 7) or desflurane (n = 7). Arterial and mixed venous blood samples were obtained during wash-in and wash-out of volatile anesthetics before and during bronchoconstriction by methacholine inhalation (100 μg/ml). Total uptake and elimination were calculated based on partial pressure measurements by micropore membrane inlet mass spectrometry and literature-derived partition coefficients and assumed end-expired to arterial gradients to be negligible. VA/Q distribution was assessed by the multiple inert gas elimination technique.

Results: Before methacholine inhalation, isoflurane arterial partial pressures reached 90% of final plateau within 16 min and decreased to 10% after 28 min. By methacholine nebulization, arterial uptake and elimination delayed to 35 and 44 min. Desflurane needed 4 min during wash-in and 6 min during wash-out, but with bronchoconstriction 90% of both uptake and elimination was reached within 15 min.

Conclusions: Inhaled methacholine induced bronchoconstriction and inhomogeneous VA/Q distribution. Solubility of inhalational anesthetics significantly influenced pharmacokinetics: higher soluble isoflurane is less affected than fairly insoluble desflurane, indicating different uptake and elimination during bronchoconstriction.