This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Landsverk, S. A. Articles by Kirkeboen, K. A. Search for Related Content PubMed PubMed Citation Articles by Landsverk, S. A. Articles by Kirkeboen, K. A. Related Collections Mechanisms Clinical Pharmacology Technology Pharmacology

---

ANESTHETIC PHARMACOLOGY

The Effects of General Anesthesia on Human Skin Microcirculation Evaluated by Wavelet Transform

Svein Aslak Landsverk, MD^*, Per Kvandal, MD, Alan Bernjak, BSc, Aneta Stefanovska, PhD, and Knut A. Kirkeboen, MD, PhD^*||

From the Departments of *Anesthesiology, Intensive Care Medicine, Ulleval University Hospital, Oslo, Norway; Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia; Department of Physics, Lancaster University, Lancaster, UK; and ||Institute for Experimental Medical Research, Ulleval University Hospital, Oslo, Norway.

Address correspondence and reprint requests to Svein A. Landsverk, MD, Department of Anesthesiology, Ulleval University Hospital, 0407, Oslo, Norway. Address e-mail to s.a.landsverk{at}medisin.uio.no.

BACKGROUND: Time-frequency analysis of the laser Doppler flowmetry signal, using wavelet transform, shows periodic oscillations at five characteristic frequencies related to the heart (0.6–2 Hz), respiration (0.15–0.6 Hz), myogenic activity in the vessel wall (0.052–0.15 Hz), sympathetic activity (0.021–0.052 Hz), and very slow oscillations (0.0095–0.021), which can be modulated by the endothelium-dependent vasodilator acetylcholine. We hypothesized that wavelet transform of laser Doppler flowmetry signals could detect changes in the microcirculation induced by general anesthesia, such as alterations in vasomotion and sympathetic activity.

METHODS: Eleven patients undergoing faciomaxillary surgery were included. Skin microcirculation was measured on the lower forearm with laser Doppler flowmetry and iontophoresis with acetylcholine and sodium nitroprusside before and during general anesthesia with propofol, fentanyl, and midazolam. The laser Doppler flowmetry signals were analyzed using wavelet transform.

RESULTS: There were significant reductions in spectral amplitudes in the 0.0095–0.021 (P < 0.01), the 0.021–0.052 (P < 0.001), and the 0.052–0.15 Hz frequency interval (P < 0.01) and a significant increase in the 0.15–0.6 Hz frequency interval. General anesthesia had no effect on the difference between acetylcholine and sodium nitroprusside on relative amplitudes in the 0.0095–0.021 Hz frequency interval (P < 0.001).

CONCLUSION: General anesthesia reduces the oscillatory components of the perfusion signal related to sympathetic, myogenic activity and the component modulated by the endothelium. However, the iontophoretic data did not reveal a specific effect on the endothelium. The increase in the 0.15–0.6 Hz interval is related to the effect of mechanical ventilation.

This article has been cited by other articles:

				J. M. B. Newman, R. M. Dwyer, P. St-Pierre, S. M. Richards, M. G. Clark, and S. Rattigan Decreased microvascular vasomotion and myogenic response in rat skeletal muscle in association with acute insulin resistance J. Physiol., June 1, 2009; 587(11): 2579 - 2588. [Abstract] [Full Text] [PDF]

				E. L. Ritman, N. Charkoudian, A. Carpi, M. Rossi, P. J. Owen-Lynch, B. W. Wilkins, and C. Demougeot Commentary on viewpoint: the human cutaneous circulation as a model of generalized microvascular function. J Appl Physiol, July 1, 2008; 105(1): 373 - 373. [Full Text] [PDF]