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Melatonin plays an important role in aging and relevant neurodegeneration as an antioxidant and neuroprotector. It can interact with β-amyloid (Aβ) generation, inhibit formation of β-sheet and amyloid fibrils, modulate apoptosis, and protect cholinergic system function in Alzheimer's disease animal model. Recently, its effects on anesthetic-induced neurodegeneration have received more attention, and in this investigation, we explored whether melatonin can attenuate Aβ1-40 generation and cholinergic dysfunction in the hippocampus of aged rats induced by isoflurane through enzyme-linked immunosorbent assay, Western blot, immunohistochemistry, and immunofluorescence. The results showed that isoflurane increased Aβ1-40 generation and caused cholinergic dysfunction through decreasing choline acetyltransferase (ChAT) expression in the hippocampus in a dose-dependent way, and intraperitoneal melatonin premedication attenuated the neurodegeneration through inhibiting Aβ1-40 generation and increasing ChAT expression, and its effects were more obvious in high-concentration isoflurane group. Collectively, our results provide evidence for the therapeutic value of melatonin on isoflurane-induced neurodegeneration, including Aβ1-40 generation and cholinergic dysfunction, and further work is necessary to clarify its target sites and detailed mechanisms. [ABSTRACT FROM AUTHOR]

Compares the effects of alfentanil and esmolol on hemodynamic and catecholamine response to tracheal intubation. Moderation of hemodynamic response to tracheal intubation by esmolol; Attenuation of hemodynamic and catecholamine responses due to alfentanil; Measurement of systolic and diastolic blood pressure; mean blood pressure, heart rate, dopamine, norepinephrine and epinephrine.

Investigates the effects of propofol compared to thiopentoneon in preventing hemodynamic response to tracheal intubation. Advantage of propofol; Measurement of blood pressure and heart rate; Details the linear regression analysis.

ocuses on clinical study of patient-controlled epidural analgesia with tetracaine hydrochloride after pulmonary lobectomy. Measurement of peak expired flow after the surgery; Classification of the patients into tetracaine and ropivacaine groups; Analysis of visual analogue scale scores in both groups.

Objective. To assess patients' knowledge, attitudes, and concerns regarding anesthetic management. Methods. A survey of 55 items was developed and administered preoperatively to 500 patients including 190 men and 310 women in our hospital. Patients were interviewed on their knowledge of the role of anesthesiologists, their preferences regarding anesthetic management, and also their concern about potential anesthetic complications. Results. Patients' perceptions of anesthesiologists' training and role have roached a certain level. Most significant preoperative concerns regarding the anesthesiologists focused on experience, qualifications, and presence or absence during the anesthesia. Patients' concerns also included the possibility of not being waken up following anesthesia, experiencing postoperative pain, and becoming paralyzed. The variations of concerns depended partially on patients' sex, type of anesthesia, and proposed surgical procedure, partially on their education and living environments. Conclusion. It is suggested that anesthesiologists address significant patient concerns during the preoperatire visit to enhance their effectiveness in patient care. Efforts to educate the public on the anesthesiologists' role in preoperative care would improve patients' confidence. [ABSTRACT FROM AUTHOR]

Objective: To investigate clinical features of pheochromocytoma and summarize experiences of anesthetic management during the perioperative period., Methods: Two hundred and fifty eight patients who were diagnosed with pheochromocytoma in our hospital were reviewed retrospectively for clinical features. According to different preoperative pharmalogical preparations, perioperative mortalities were analyzed in three periods (Period 1: January 1955 - December 1975; Period 2: January 1976 - December 1994; Period 3: January 1995 - July 2001). In Period 3, hemodynamic changes in the patients undergoing different anesthetic methods were analyzed., Results: About 5.8% (15/258) of pheochromocytoma was an integral part of multiple endocrine neoplasia (MEN) type II or mixed type. Sixty percent (149/249) of the patients who had undergone surgery possessed evidence of catecholamine cardiac toxicity preoperatively. Impaired glucose tolerance was found in 59% (147/249) of the patients before surgery. Perioperative mortality was significantly decreased from 8% (5/60) in Period 1 to 1.2% (1/75) in Period 2 (P < 0.01). No perioperative deaths occurred in Period 3. The volume infused during the operation was significantly higher both in the epidural anesthesia group (3474 ml +/- 624 ml, P < 0.01) and in the epidural plus general anesthesia group (3654 ml +/- 475 ml, P < 0.01) than in the general anesthesia group (2534 ml +/- 512 ml). There were favorable hemodynamic characteristics in patients before removal of the tumor in the epidural anesthesia group and in the epidural plus general anesthesia group, as compared with the general anesthesia group., Conclusions: A positive surgical outcome of the excision of pheochromocytoma depends on multiple factors, including careful assessment of potential vital organ damage before surgery and restoration of blood volume by establishing alpha-blockade preoperatively, meticulous anesthetic management of patients during surgery, and appropriate circulatory support after surgery.

Objective: To compare the efficacy and safety of remifentanil and fentanyl in patients undergoing a modified radical mastectomy or total hysterectomy., Methods: Fifty-four patients were evenly randomised into remifentanil group and fentanyl group. Anesthesia was induced by propofol (1 - 2 mg/kg) and either remifentanil (2 microg/kg) or fentanyl (2.5 microg/kg), and was maintained with inhalation of nitrous oxide in oxygen (2:1) and continuous infusion of either remifentanil (0.2 microg.kg(-1).min(-1)) or fentanyl (0.03 microg.kg(-1).min(-1))., Results: The number of patients exhibiting light anesthesia responses in the remifentanil group during intubation and the maintenance of anesthesia was significantly less than that in the fentanyl group. Both systolic and diastolic blood pressures in the fentanyl group were significantly higher than those in the remifentanil group during intubation, skin incision, maintenance of anesthesia and extubation. The time to opening eyes on command and the time for extubation after surgery was comparable between the two groups. More patients in the remifentanil group (25 patients) required bolus injection of morphine for postoperative pain relief than those in the fentanyl group (5 patients, P < 0.05). There was no significant difference between the two groups in terms of side effects., Conclusions: Under the condition of this study protocol, the anesthetic and analgesic effects of remifentanil are more potent than those of fentanyl. Remifentanil can offer superior intraoperative hemodynamic stability in comparison with fentanyl, and has no compromising recovery from anesthesia.

Objective: To investigate the effectiveness of using a medium molecular weight hydroxyethyl starch solution (HES) administered as a replacement for estimated blood loss (EBL) during cytoreductive surgery for ovarian cancer on splanchnic oxygenation., Methods: Forty-two patients undergoing cytoreductive surgery for ovarian cancer were enrolled in this prospective randomized study. As soon as the EBL exceeded 10% but was less than 20% of the estimated blood volume, the patients were randomly assigned to receive either a volume of lactated Ringer's solution (LRS) equal to three times the EBL (LRS group, n = 22) or a volume of 6% HES equal to the EBL (HES group, n = 20). Tissue oxygenation was assessed indirectly by measuring tonometric parameters, including the difference between gastric intramucosal PsCO(2) and arterial PaCO(2) (Ps-a CO(2) gap), gastric intramucosal pH (pHi) and arterial lactate acid concentration at 30 min after induction of anesthesia (baseline value), 1 hour and 2 hours after skin incision, and at the end of surgery., Results: At the end of surgery,the Ps-a CO(2) gap in the HES group (8.7 +/- 1.6 mmHg) was significantly lower than that of the LRS group (18.74 +/- 4.4 mmHg, P < 0.01), while the pHi (7.30 +/- 0.05 mmHg) in the HES group was significantly higher than that of the LRS group (7.21 +/- 0.07 mmHg, P < 0.01). There was no significant difference between the two groups in terms of arterial lactate acid concentration., Conclusion: In patients undergoing major surgery with relatively large blood losses, volume resuscitation with medium molecular weight hydroxyethyl starch solution may improve splanchnic blood flow and tissue oxygenation.

Objective: To investigate clinical features and anesthetic management of multiple endocrine neoplasia (MEN) associated with pheochromocytoma., Methods: Medical records of patients who were diagnosed as multiple endocrine neoplasia associated with pheochromocytoma in our hospital from April 1977 to April 2001 were reviewed retrospectively. The demographic data, clinical presentations, family history, biochemical examinations, type of MEN, sequence of different surgical procedures, anesthetic methods and hemodynamics during surgery were analyzed., Results: Thirteen cases of MEN associated with pheochromocytoma were investigated, accounting for 6% (13/213) of the pheochromocytoma patients admitted into our hospital. Nine of the 13 patients presented as type IIa MEN (Sipple syndrome), one as type IIb MEN, and three as mixed MEN. Four patients with type IIa MEN had a family history of similar disease. Five patients with other coexisting endocrine disorders first underwent excision of the pheochromocytomas, although only two had hypertensive symptoms at the time of admittance. Seven patients without histories of hypertension received surgical treatment for pheochromocytoma secondly. The excision of pheochromocytoma was performed under general anesthesia in 8 patients and epidural block in 4 patients. Marked hemodynamic fluctuation was recorded in 8 patients. No perioperative death was recorded., Conclusion: Pheochromocytoma may be linked to other endocrine disorders during MEN, either as the main clinical presentation or most frequently as an occult tumor. Recognition of this feature of pheochromocytoma is of importance to the improvement of diagnosis and treatment both for pheochromocytoma and MEN.

Objective: To investigate the clinical features of pheochromocytoma and summarize the experience of anesthetic management during perioperative period., Methods: Two hundred and fifty eight medical records of patients who were diagnosed as pheochromocytoma in Peking Union Medical College Hospital were reviewed retrospectively for clinical features, anesthetic management and perioperative mortality., Results: About 5.8% (15/258) of pheochromocytomas was an integral part of multiple endocrine neoplasia (MEN) type II or mixed type. Sixty percent (149/249) of the patients undergoing surgery possessed evidence of catecholamine cardiac toxicity preoperatively, including abnormal ECG, myocardial hypertrophy and decreased left ventricular ejective fraction. Impaired glucose tolerance was found in 59% (147/249) of patients before surgery. The volume infused during operation was significantly higher both in the epidural anesthesia group (3 474 ml +/- 624 ml, q(1) = 5.72, P < 0.01) and in the epidural plus general anesthesia group (3 654 ml +/- 475 ml, q(2) = 5.83, P < 0.01) than that in the general anesthesia group (2 534 ml +/- 512 ml). There were favorable hemodynamic characteristics before removal of the tumor in the epidural anesthesia group and epidural plus general anesthesia group, as compared with in the general anesthesia group. Perioperative mortality was significantly decreased from 8% (5/60) in period 1 (from 1955 to 1975) to 1.2% (1/75) in period 2 (from 1976 to 1994) (chi(2) = 4.05, P < 0.01). No perioperative death (0/111) occurred in period 3 (from 1995 to 2001)., Conclusion: A good surgical outcome for the excision of pheochromocytoma depends on multiple factors, including careful assessment of potential end organ damages and restoration of blood volume by establishing alpha-blockade during the preoperative period, meticulous anesthetic management during surgery, and appropriate circulatory support after surgery.