Çalışma koroner arter cerrahisinde entübasyon, cilt insizyonu ve sternotomiye bağlı hemodinamik değişikliklerle bispektral indeks değerleri arasındaki korelasyonu araştırmak amacıyla planlandı. Koroner arter grefti yapılacak 35 hastaya EKG, puls oksimetre, invaziv arteriyel kan basıncı ve bispektral elektroensefalogram (BİS) monitorizasyonu yapıldı. Anestezi indüksiyonunda 5 $mu$g $kg^{-1}$ fentanil, 0,3 mg $kg^{-1}$ etomidat, 1,5 mg $kg^{-1}$ lidokain, 2 mg $kg^{-1}$ pankuronyum uygulandı. Endotrakeal entübasyondan sonra anestezi idamesi % 0,5-0,8 izofluran ve 10 - 20$mu$g $kg^{-1}$ $saat^{-1}$fentanil infüzyonuyla sağlandı. Kalp hızı, sistolik, diyastolik arteriyel kan basıncı ve BİS değerleri indüksiyondan ve entübasyondan önce, entübasyondan 1 ve 5 dakika sonra, cilt insizyonundan önce, 1 ve 5 dakika sonra, sternotomiden 1 ve 5 dakika sonra kayıt edildi. Vazoaktif ilaçların kullanımı ve anestezi idamesi BİS değerleri önemsenmeksizin hemodinamik değişikliklere göre ayarlandı. Sistolik arteriyel kan basıncı tüm dönemlerde, diyastolik arteriyel kan basıncı ve kalp hızı ise indüksiyondan sonra, cilt insizyonundan önce ve sonra, başlangıç değerinden düşük bulundu (p

This study was designed to investigate the correlation between bispectral index values and hemodynamic changes observed following intubation, incision and sternotomy in coronary bypass surgery. Electrocardiographic changes, peripheral tissue oxygen saturation, invasive arterial pressure and bispectral electroencephalogram (BIS) were monitored in 35 patients undergoing coronary bypass surgery. Anesthesia was induced with fentanyl (5 $mu$g kg'1), etomidate (0.3 mg $kg^{-1}$ lidocaine (1.5 mg $kg^{-1}$), and pancuronium (2 mg $kg^{-1}$'). Following endotracheal intubation, anesthesia was maintained using isoflurane (0.5-0.8 %) and fentanyl infusion (10 -20 $mu$ $kg^{-1}$ $h^{-1}$). Heart rate, systolic and diastolic arterial blood pressure and BIS readings were monitored continuously' and documented before induction and intubation, 1 and 5 minutes after intubation, before skin incision, 1 and 5 minutes after skin incision, and l and 5 minutes after sternotomy. Vasoactive drug doses and anesthetic agents were adjusted according to hemodynamic changes without paying attention to BIS values. Systolic arterial blood pressure was observed to be lower than baseline at all times. Diastolic pressure and heart rate were found to be lower than baseline after induction of anesthesia, before and after skin incision (p<0.05). Systolic and diastolic arterial blood pressures were signiflcantly higher (p<0.05) following intubation, skin incision, and sternotomy compared with pre-intubation pre-incision values. BIS values were decreased following anesthesia induction (from 92.8±5.7 before in-duction to 37.2±7.3 post induction) and remained minin the deep hypnotic range (between 41.5±4.7 to 44.5±8.5) throughout the operation. BIS readings did not change signiflcantly after intubation, skin incision, and sternotomy. There was no correlation between hemodynamic changes resulting from intubation, skin incision, and sternotomy and BIS values. Even though BIS values reveal deep hypnosis, hemodynamic changes may be observed following painful stimulation during coronary artery bypass surgery.