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Objective: To audite and compare the perioperative practices of intravenous fluids and electrolyte & glucose monitoring in children undergoing operations for scoliosis in 2008, 2010, prior to and after the publication of guideline in 2009., Methods: Retrospective audit was conducted at Peking Union Medical College Hospital, a tertiary referral teaching hospital in Beijing, China. Children under 14 years old with scoliosis treated surgically in 2008 and 2010 were recruited. The following data were collected from medical files: age, gender, weight, duration of hospitalization, concurrent illness, operation, anesthesia, fluid prescribed during perioperative fasting period, electrolyte monitoring and postoperative pain control, etc., Results: Among 235 American Society of Anesthesiologists (ASA) I-II cases, 75 children received dextrose 5% or saline 0.9% during the preoperative fasting period. Intraoperatively, the anesthesiologists preferred dextrose 5% or saline 0.9% in children under 6 years old (n = 15, 2008; n = 15, 2010) and Ringer's solution in those aged 6 - 14 years (n = 84, 2008; n = 94, 2010) and hypotonic fluid was not used. And 82.3% and 94.3% of them received electrolyte examinations preoperatively. The electrolyte results were unavailable postoperatively in 27/122 (in 2008) and 13/113 (in 2010) and serum electrolytes were not assessed before fluid treatment postoperatively. Electrolytes were monitored only once in 82.3% (in 2008) and 70.5% (in 2010) patients. Compared with the preoperative concentration of sodium ion, the mean decrease was approximately 2.0 mmol/L at Day 1 postoperation. Hyponatremia at Day 1 postoperation in 2010 was more common than that in 2008 (26.2% vs 23.6%; P = 0.044). But no significant difference existed between the incidence of hyperglycemia of the same day in 2008 and that in 2010 (P = 0.306)., Conclusion: Compared with that in 2008, our recent practice of intravenous fluid prescription and electrolyte monitoring is ill-consistent with the recommendations in 2009. Implementation of optimal perioperative fluid management is warranted.

Objective: To investigate the effects of melatonin on voltage-gated delayed rectifier potassium channels., Methods: Hippocampus neurons were obtained from newborn Wistar rat and cultured. Primary cultured for 7 to 12 days of new-born Wistar rat were selected as objectives. Patch clamp whole-cell recording technique was used on the hippocampus neurons cultured for 7 to 12 day. to record the delayed rectifier potassium current to analyze the basic electrophysiological characteristics. The effects of melatonin of the concentrations of 1 nmol/L, 10 nmol/L, 100 nmol/L, 1 mol/L, 10 mol/L, 100 mol/L, and 1 mmol/L on the amplitudes and kinetics of delayed rectifier potassium currents were investigated., Results: With different voltage protocols and specific blockers of potassium channel (4-AP and TEA) a delayed rectifier potassium current that activated and inactivated slowly and had the outward rectifying characteristics (Ik) from the outward potassium currents in cultured new-born hippocampus neurons was separated. The effect of melatonin on the delayed rectifier channel was rapid, reversible and voltage-dependent Melatonin had no effect on the kinetic characteristics of the I -V curve. Melatonin increased the potassium current concentration-dependently. 1 - 100 nmol/L melatonin increased the amplitude of potassium current gradually; the effects of 1 - 100 micromol/L melatonin on the potassium current increased concentration-dependently, while the action of 1 mmol/L melatonin decreased., Conclusion: Melatonin reversibly increases the rectifier delayed potassium currents of the cultured hippocampus neurons of new-born rat. This may be involved in some aspects of physiological and pathological significance of potassium currents.

Objective: To investigate the circadian rhythm of perioperative melatonin secretion in patients undergoing coronary artery bypass grafting surgery., Methods: Forty male patients scheduled for elective coronary artery bypass grafting surgery (CABG) under hypothermic cardiopulmonary bypass (CPB) or off-pump were allocated into two groups of 20 patients: CPB group and off-pump group. Blood samples were withdrawn from all patients immediately before the induction of anesthesia (baseline), 10 min after the induction of anesthesia, 10 min after heparinization, 30 min after commencement of CPB (or 2h after skin incision), before reversal of heparin with protamine, at the end of surgery, and. every 3 hours after operation until the twenty-fourth hour. The plasma concentration of melatonin was measured by using enzyme-linked immunosorbent assay., Results: The plasma melatonin concentrations during and after CPB were higher than the baseline value in the CPB group. There were no differences in the melatonin concentrations in the off-pump group. In the CPB group the melatonin concentrations after induction, during CPB, and after CPB were 7.2 +/- 3.4, 10.5 +/- 5.2, and 9.5 +/- 4.0 respectively, all significantly higher than those in the off-pump (5.5 +/- 2.5, 6.3 +/- 2.0, and 5.7 +/- 2.1 respectively, all P < 0.05). During the twenty-four hours after operation, two patients in the CPB group and six patients in the off-pump group showed circadian rhythm of melatonin secretion., Conclusion: The perioperative circadian rhythm of melatonin secretion in patients undergoing CABG surgery with CPB or off-pump is disturbed, however relatively more patients under off-pump group regain secretion rhythm of melatonin in the immediate postoperative period. CPB may be one of the reasons for perioperative melatonin circadian secretion disturbance.

Objective: To evaluate the effects on blood sparing and risk of hematogenous tumor dissemination of the use of blood salvage machine in oncologic surgeries., Methods: The clinical data of 13 patients, 6 with malignant tumors and 7 with benign tumors, who received the use of blood salvage machine during oncologic surgeries based on informed consent, were analyzed., Results: In total 42,575 ml of packed red blood cells were collected during surgery with a mean value of 3 275 ml (400 - 1500 ml) per patient. The average amount of allogenic transfusion per patient was 1 530 ml (0 - 8,000 ml). The number of blood salvage machine use in oncologic surgeries accounted for 8.6% (13/152) of the total number of blood salvage machine use in surgeries in that period. The perioperative mortality rate of the oncologic surgeries with the use of blood salvage machine was 7.7% (1/13). The post-operative metastasis rate of liver and lung was 15.4% (2/13)., Conclusion: The use of blood salvage machine during oncologic surgeries improves the blood sparing effect. However, it cannot be used routinely, since it may result in hematogenous tumor cell dissemination.

Objective: To study the effects of general anesthesia combined with epidural anesthesia (GEA) and pure general anesthesia (GA) on the surgical stress response and cytokines in pulmonary surgery., Methods: Twenty patients submitted to elective pulmonary surgery were randomly divided into 2 groups of 10 patients: GEA group receiving general anesthesia combined with thoracic epidural analgesia and GA group receiving only general anesthesia. Blood samples were taken before induction, at incision, 2 h, 4 h, 6 h following the incision, and in the 1st and 3rd postoperative day. IL-6, ACTH and cortisol were detected with radioimmunoassay., Results: (1). The concentration of ACTH was similar in the 2 groups before operation, was remarkably increased 2 hours postoperatively (P < 0.05), reached the peak values 2 approximately 4 hours after the incision in most patients (P < 0.01), and returned to the preoperative levels one day after operation without a significant difference at every time point between the two groups. (2). The concentration of cortisol decreased transiently during incision in the GEA group (P < 0.05), then increased gradually, was significantly higher than the preoperative level (P < 0.01), and remained at the high level till the morning of the 1st day after operation (P < 0.01). In the GA group the cortisol concentration was higher than that before operation 2 hours after incision (P < 0.01), and remained at the level higher than that before operation 4 h and 6 h after incision (P < 0.01), and returned to the normal level by the morning of the 3rd day. The cortisol concentration 2 hours after incision in GEA group was significantly lower than that in GA group (P < 0.05), however, the peak concentrations of these 2 groups were not significantly different (P > 0.05). In the GA group the IL-6 concentration began to increase after operation, became significantly different from that before operation 4 hours after operation (P < 0.01), reached the peak level in the morning of the first postoperative day (P < 0.05), and returned to the preoperative level in the third day. In the GEA group the IL-6 concentration began to increase 2 hours after operation (P < 0.05), and returned to the preoperative level in the morning of the first postoperative day. The concentration of IL-6 was positively correlated with that of cortisol (r = 0.231)., Conclusion: Pulmonary surgery performed with two different anesthetic techniques causes inflammatory cytokine responses. The additional epidural anesthesia doesn't influence cytokine production. It incompletely inhibits the stress response in the early phase. IL-6 and cortisol may have some effects on each other.

Objective: To investigate the effect of medium molecular weight hydroxyethyl starch solution (HES) administered as replacement for estimated blood losses (EBL) during cytoreductive surgery for ovarian carcinoma on splanchnic oxygenation., Methods: Cytoreductive surgery was operated upon forty-two patients with ovarian carcinoma. As soon as the EBL was higher than 10% but less than 20% of the estimated blood volume, the patients were randomly assigned to receive 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 the tonometric parameters of stomach, including difference between gastric intramucosal PsCO(2) and arterial PaCO(2) (Ps-aCO(2) gap), gastric intramucosal pH (pHi) and arterial lactate acid concentration 30 min after induction of anesthesia (baseline value), 1 h and 2 h after skin incision, and at the end of surgery., Results: At the end of surgery, the Ps-aCO(2) gap was 8.7 mm Hg +/- 1.6 mm Hg in the HES group, significantly lower than that in the LRS group (18.74 mm Hg +/- 4.4 mm Hg, P < 0.01), while the pHi in the HES group was 7.30 +/- 0.05, significantly higher than that in the LRS group (7.21 +/- 0.07, P < 0.01). There was no significant difference in arterial lactate acid concentration between the two groups., Conclusion: In patients undergoing major surgery, volume resuscitation with medium molecular weight HES improves the splanchnic blood flow and tissue oxygenation.