The evaluation of the amnesic effects of midazolam used for conscious sedation via bispectral index monitorization, picture recall test and verbal information recall test in patients undergoing gynecologic surgery

Abstract

The evaluation of the amnesic effects of midazolam used for conscious sedation via bispectral index monitorization, picture recall test and verbal information recall test in patients undergoing gynecologic surgeryIn this study we aimed to evaluate the amnesic effects of midazolam used for conscious sedation via bispectral index monitorization (BIS), picture recall test and verbal information recall test in patients undergoing gynecologic surgery.One hundred and sixty patients, aging between 18-77, classed ASA I-II undergoing gynecologic surgery were included in this study. All the patients received IM 0.5 mg atropine and 50 mg meperidine 15 minutes before entering the operating room (O.R.). After entering the O.R. the patients were monitorised for electrocardiogram (ECG), systolic, diastolic and mean blood pressure (SBP, DBP, MBP), heart rate (HR) and periferic O? saturation (SpO?). Depth of anesthesia was monitorized with BIS. The patients were given % 0.9 saline solution via an 18G (gauge) catheter placed at the back of their hands. The patients ECG, SBP, DBP, MBP, HR and SpO? values are measured 3 minutes before, during and 3 minutes after the application of midazolam.To monitorize the depth of anesthesia BIS monitorization and the Observer?s Assessment of Anesthesia/Sedation (OAA/S) scale were used. The BIS and OAA/S scores were recorded 3 minutes before, during and at the 1., 2. and 3. minutes after the application of midazolam and during anesthesia induction. The patients were informed about the basics of the study.Four pictures were used in this study. All patients were shown one picture before and after midazolam. The patients were told the number of the O.R. they were going to be operated and asked to memorize. Following the application of midazolam the patients were given the words green or blue and were asked to memorize it as well. After the first picture was shown and the first information was given the patients received IV 0.04 mg/kg midazolam. 3 minutes after the application of midazolam the second picture was shown and the second information was told. IV propofol 3 mg/kg was used for anesthesia induction and in the case of endotracheal entubation rocuronium IV 0.6 mg/kg was given. Following the induction IV remifentanyl and fentanyl were used if needed. The BIS monitorization was disconnected after the induction. The day following the surgery the patients were evaluated for their recognition of the pictures and words. The patiens were asked if they had any recall of the preoperative waiting room, their entrance to the O.R., their first conversation with the anesthesiologist, the moment midazolam was given, if used the placement of an urinary catheter and whether there was any pain/discomfort during the procedure and the moment the anesthesia induction started. Their answers were recorded.In 34 patients amnesia occured at the same time midazolam was applied. None of the 9 patients who had an urinary catheter placed had any memory of this incident. Twenty patients could remember the initialization of aneshesia induction postoperatively. While the first picture could be recalled by all the patients, the second picture was recalled by 13 patients. The first word was recalled by 143 and the second was recalled by 9 patients.The patients conscious sedation with midazolam resulted in an increase in HR and decrease in SBP, DBP and MBP. By the means of hemodynamic parameters ASA I and II patients had a statistical significant difference (p0.05). When OAA/S and BIS values were evaluated according to time, for both OAA/S and BIS, the 1., 2. and 3. values recorded were all higher than the 4., 5. and 6. values (p0.05). OAA/S ve BIS değerleri zamana göre değerlendirildiklerinde her iki değer için zaman 1, 2 ve 3 te elde edilen değerlerin zaman 4, 5 ve 6'da elde edilen değerlere göre daha yüksek olduğu görüldü (p<0.05).BIS 1 değeri ile resim 2'nin, BIS 3 ve BIS İND değerleri ile kelime 2'nin ve BIS 1 değeri ile midazolam yapılmasının hatırlanması arasındaki ilişki istatiksel olarak anlamlı bulundu (p<0.05). OAA/S 1,2,3 ve İND değerleri ile resim 2'nin ve de OAA/S 2,3 ve İND değerleri ile kelime 2'nin hatırlanması arasındaki ilişki istatiksel olarak anlamlı bulundu (p<0.05). OAA/S skalası değerleri ile BIS değerlerinin korelasyonuna bakıldığında sadece OAA 1 ve BIS 1 değerleri arasında izlenen fark anlamlı bulundu (p<0.05).Resim 2 ve kelime 2'nin hatırlanması ile hastanın öğrenim durumu arasında istatiksel olarak anlamlı bir ilişki (sırasıyla p=0.047, p<0.05; p=0.03, p<0.05) izlendi. İstatiksel olarak anlamlı olmasa da üniversite mezunlarında hatırlama oranı daha yüksek bulundu.Çalışmamızın sonucunda intravenöz midazolam ile yapılan bilinçli sedasyonun, hemodinamik parametreleri etkilediğini, yeterli amnezi ve anksiyoliz sağladığını, amnezik etkilerinin BIS monitorizasyonu ve OAA/S skalası ile izlenebilmesinin mümkün olduğunu gördük. Ayrıca daha objektif bir değer sağladığından ve daha kolay değerlendirildiğinden amneziyi izlemede BIS monitorizasyonunun kullanılmasının daha faydalı olacağı kanısına vardık.Anahtar kelimeler: Midazolam, amnezi, anestezi derinliği, BIS, OAA/S