Korean J Anesthesiol.  2007 Jun;52(6):S77-S81. 10.4097/kjae.2007.52.6.S77.

Cerebral Ischemia Detected by the Bispectral Index during Cardiopulmonary Bypass: A case report

• Lee EH
• Choi JW
• Cho SJ
• Sim JY
• Hahm KD
• Jeong YB
• Choi IC

• KMID: 2299189
• DOI: http://doi.org/10.4097/kjae.2007.52.6.S77

Abstract

The bispectral index (BIS) has been developed as a measure for monitoring the hypnotic drug effect. EEG processing results in a BIS scale from 0 to 100, where 100 represents an awake and responsive patient, and the scale decreases when hypnotics are administered. Here we describe two patients in whom the BIS decreased to nearly 0 during cardiac surgery. Postoperatively both patients showed hypoxic brain injury. There are several possible causes for a decrease in the BIS during surgery, including deep anesthesia, hypothermia and cerebral ischemia. In the present cases, cerebral hypoperfusion was the likely cause. During cardiac surgery, hemodynamic changes such as acute hypotension and cardiac arrest can cause cerebral ischemia. Cerebral ischemia develops most commonly during cardiopulmonary bypass (CPB). Therefore, the BIS may be useful for detecting severe cerebral ischemia during CPB, although it has some limitations as a cerebral monitor.

Keyword

bispectral index; cardiac surgery; cardiopulmonary bypass; cerebral hypoperfusion

MeSH Terms

Anesthesia
Brain Injuries
Brain Ischemia*
Cardiopulmonary Bypass*
Electroencephalography
Heart Arrest
Hemodynamics
Humans
Hypnotics and Sedatives
Hypotension
Hypothermia
Thoracic Surgery
Hypnotics and Sedatives