1. In a laparoscopic surgery, a learning doctor followed up this surgery. At first anaesthesia is steady, Narcotrend stage D2, index 42, HR 78, BP 105/60mmHg. As it is need to push air to abdomen, after a while, BP increased, systolic BP to 175. Doctor thought that anaesthetic dosage was not enough, so he decided to increase the dosage, and caused too deep anaesthesia. And Narcotrend stage is F0, index is 12. Narcotrend showed that the depth of anaesthesia is too deep, it may be caused by operation stimulation (hemodynamics of abdominal aortic) Is it suitable to reduce BP by anaesthetics?
After Head doctor knew the situation, he analyzed: Because of pushing air to abdomen, pressing abdominal aortic and causing excitability such as hemodynamis increasing etc. then BP increased rapidly, at the same time Narcotrend showed that the depth of anaesthesia was suitable, if continued increasing anaesthetics, would cause too deep anaesthesia. It should be given antihypertensive drugs to control the BP in the suitable range.
Summary: Narcotrend can accurately monitoring depth of anaesthesia, prompt the anaesthetists to use suitable plan and drug, show the right way to the young doctors.

2. During a thoracic operation, a young doctor used desflurane and propofol to induce fast. Because of fast induce, it is used to increase inhalation at the beginning, and then the inhalation should be reduced after induce finished and turn into operation. However, the doctor forgot to turn down volatility pot and reduce inhalation, so Narcotrend indicated anesthesia depth F0, anesthesia too deep. That doctor remembered he operated it normally without mistake, and he doubted the equipment is not accurate. So he asked the management professor to observe and judge, after checking, the professor thought the equipment is normal, then he checked the TCI infusion and volatility pot and found the problem,. After adjusting inhalation normally, Narcotrned index rise and classification keep in E0. The young doctor was surprised. This operation proves the high accuracy of Narcotrend again.
Conclusion of doctor: Narcotrend can monitor depth of anesthesia accurately and help doctors to discover inappropriate operation during anesthesia, and even help to find other equipments work normally or not.
It proves that Narcotrend can instruct to use anesthetic evidently. Blood pressure is too low is not caused by deep anesthesia, but caused by shortage blood volume of the patient. Then colloids can be supplemented to patient to maintain normal blood pressure, so that to get accurate anesthesia.

3. Narration of a professor: a postgraduate was carrying on a gastric carcinoma operation, he tried to reduce dosage of anesthetic to maintain blood pressure. But the patient hadn’t have food for about two days before operation, which made blood pressure was too low during operation and the RR SYST was only a little more than 50. When that postgraduate reducing dosage of anesthetic, blood pressure increased a little but not evidently, but Narcotrend classification rise from D to C, anesthesia was too light.