Effects of the tourniquet deflation on bispectral index during knee arthroscopic surgery under the general anesthesia

Jeong Hyun Choi; Joon Kyung Sung; Sung Wook Park; Wha Ja Kang

doi:10.4097/kjae.2009.56.4.371

Effects of the tourniquet deflation on bispectral index during knee arthroscopic surgery under the general anesthesia

Korean J Anesthesiol. 2009 Apr;56(4):371-374. doi: 10.4097/kjae.2009.56.4.371.

Authors

Jeong Hyun Choi¹, Joon Kyung Sung¹, Sung Wook Park¹, Wha Ja Kang¹

Affiliation

¹ Department of Anesthesiology and Pain Medicine, School of Medicine, Kyung Hee University, Seoul, Korea. whakang@hotmail.com.

PMID: 30625755
DOI: 10.4097/kjae.2009.56.4.371

Abstract

Background: Tourniquet deflation during lower extremity surgery affects the hemodynamics and metabolism of the patient, which can affect brain activity. This study examined the changes in brain activity during tourniquet deflation by measuring the bispectral index (BIS).

Methods: The BIS was measured during surgery in forty patients who had received knee arthroscopic surgery under general anaesthesia. The BIS was measured 5 minutes before deflation (DB5) and 5 minutes after deflation (DA5).

Results: The BIS at DB5 and DA5 was 50.2 +/- 9.9 and 44.4 +/- 10.4, respectively. The BIS of DA5 was significantly lower than that of DB5 (P < 0.05).

Conclusions: Tourniquet deflation during lower extremity surgery decreases the BIS associated with hemodynamic and metabolic changes. However, its clinical significance in neurologically critical patients, such as geriatric or neurologically disabled patients, remains to be clarified.

Keywords: Bispectral index; Knee arthroscopic surgery; Tourniquet.