The Detection of Cerebral Hypoperfusion with Bispectral Index Monitoring During General Anesthesia

Abstract

We describe a patient in whom the bispectral index (BIS) decreased to 0 during surgery. A 42-yr-old man with chronic renal failure was scheduled to undergo construction of an arteriovenous shunt. He had a history of acute cerebral hemorrhage. An intracranial hematoma had been removed a month earlier with almost complete neurological recovery. He had uncontrolled hypertension. His systolic blood pressure was 180 mm Hg before anesthesia induction. Anesthesia was induced with 100 mg of propofol and 3% sevoflurane. After laryngeal mask insertion, anesthesia was maintained with nitrous oxide 60% in oxygen and sevoflurane. BIS decreased to near 0 on 2 occasions: after anesthesia induction and shortly after the start of the surgery. His systolic blood pressure decreased to 110 mm Hg and BIS increased when his blood pressure was increased to 130-140 mm Hg. The decrease in BIS was suspected to be the result of decreased cerebral blood flow. The systolic blood pressure of 110 mm Hg (mean blood pressure, 80 mm Hg) was probably less than the lower limit of autoregulation. Although BIS has some limitations as a cerebral monitor, it was useful for detecting possible cerebral hypoperfusion in this case.

Necessity of adequate monitoring during carotid body tumors

“…There have been several case reports in the literature of use of bispectral index for detection of inadequate cerebral perfusion (6,7). In a recent study by Bonhomme et al (8), a decrease in the BIS values was significantly correlated to an increase in suppression ratio and a longer time between induction and carotid cross clamping.…”

The Effectiveness of Bispectral Index Monitoring on Carotid Endarterectomy with General Anesthesia

“…Pediatrik kardiyak cerrahi olgularında gelişen hipotansiyon, serebral kan akımının azalması ve serebral oksijen tüketiminin hızla değiştiği durumlarda BIS değerlerinin, serebral oksijen satürasyonu değerleriyle eşzamanlı azaldığı bildirilmiştir (13,14) . Serebral kan dolaşımının azalmasıyla sonuçlanan intrakraniyal hematom (9) ve kardiyak arrest gelişen olgularda BIS değerlerinde ani azalmalar tespit edilmiş ve bu olgularda BIS monitörü, kardiyak ressüsitasyon uygulaması sırasında serebral fonksiyonların geri dö-nüş takibi için de kullanılmıştır (22,23) .…”

“…Sedasyon ve bilinç düzeyi ile korelasyon gösteren özel ve kompleks bir EEG parametresi olan bispektral indeks (BIS) monitörü, ameliyat sırasında gelişebile-cek iskemik beyin hasarı tespiti için tasarlanmamış olmasına rağmen (8) , literatürde yetersiz beyin perfüz-yonuna bağlı BIS değerlerinde ani ve beklenmeyen azalmalar saptanan ve BIS değişikliklerinin nörolojik komplikasyonlarla ilişkilendirildiği olguların sunulduğu çeşitli çalışmalar mevcuttur (9)(10)(11)(12)(13)(14)(15) .…”

Brain Monitoring With Electroencephalography and the Electroencephalogram-Derived Bispectral Index During Cardiac Surgery

“…Similarly, BIS and raw EEG may be useful for detecting brain ischemia, especially when anesthesia is stable, if the insult is sudden, extended or located in the frontal area, and if the preoperative EEG was normal. 57 It is possible that more targeted monitors, such as cerebral oximeters, 58,59 transcranial Doppler 60 and jugular bulb venous saturation 61 might have more utility in this regard.…”