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

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

• Choi JH
• Sung JK
• Park SW
• Kang WJ

• KMID: 2236520
• DOI: http://doi.org/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.

Keyword

Bispectral index; Knee arthroscopic surgery; Tourniquet

MeSH Terms

Anesthesia, General
Arthroscopy
Brain
Hemodynamics
Humans
Knee
Lower Extremity
Tourniquets