Low-dose Simvastatin Increases Skeletal Muscle Sensitivity to Caffeine and Halothane.

Objective To determine whether the myotoxic side effects of statin simvastatin affect skeletal muscle's sensitivity to caffeine and halothane.Methods Primary cultured neonate rat skeletal myotubes were treated with 0.01-5.0 µmol/L simvastatin for 48 hours. MTT was used to evaluate cellular viability. The gross morphology and microstructure of the myotubes were observed with a light and electron microscope, respectively. The intracellular calcium concentrations ([Ca2+]i) at rest and in response to caffeine and halothane were investigated by fluorescence calcium imaging. Data were analyzed by analysis of variance (ANOVA) test.Results Simvastatin (0.01-5.0 µmol/L) decreased myotube viability, changed their morphological features and microstructure, and increased the resting [Ca2+]i in a dose-dependent manner. Simvastatin did not change myotube's sensitivity to low doses of caffeine (0.625-2.5 mmol/L) or halothane (1.0-5.0 mmol/L). In response to high-dose caffeine (10.0 mmol/L, 20.0 mmol/L) and halothane (20.0 mmol/L, 40.0 mmol/L), myotubes treated with 0.01 µmol/L simvastatin showed a significant increase in sensitivity, but those treated with 1.0 µmol/L and 5.0 µmol/L simvastatin showed a significant decrease. The sarcoplasmic reticulum Ca2+ storage peaked in the myotubes treated with 0.01 µmol/L simvastatin, but it decreased when cells were treated with higher doses of simvastatin (0.1-5.0 µmol/L).Conclusions The myotoxic side effect of simvastatin was found to change the sensitivity of myotubes in response to high-dose caffeine and halothane. When dose was low, sensitivity increased mainly because of increased Ca2+ content in the sarcoplasmic reticulum, which might explain why some individuals with statin-induced myotoxic symptoms may show positive caffeine-halothane contracture test results. However, when the dose was high and the damage to the myotubes was severer, sensitivity was lower. It is here supposed that the damage itself might put individuals with statin-induced myotoxic symptoms at greater risks of presenting with rhabdomyolysis during surgery or while under anesthesia.

[Influence of different tranexamic acid administration methods during and after cardiac surgery on coagulation function and postoperative blood loss].

OBJECTIVE: To evaluate the influence of different tranexamic acid administration methods during and after cardiac surgery with cardiopulmonary bypass(CPB) on coagulation function and postoperative bleeding. METHODS: Patients undergoing elective cardiac surgery with use of CPB (n=60) were randomized in a double-blind fashion to one of two treatment groups:group A(n=30) , administered with tranexamic acid 10 mg/kg (intravenous injection slowly before skin incision) , followed by infusion of normal saline until postoperative 12 hours;and group B(n=30) , administered with tranexamic acid 10 mg/kg(intravenous injection slowly before skin incision) , followed by infusion of tranexamic acid 1 mg/(kg·h) until postoperative 12 hours. Hemoglobin, platelet count, and coagulation function were assessed before anesthesia induction, after surgery, 8am next day and 24 hours after surgery. Bleeding, allogeneic blood transfusion, and fluid infusion during the postoperative 24 hours were recorded. RESULT: No differences were found between groups in terms of coagulant function, postoperative bleeding, allogeneic blood transfusion, and fluid infusion(P>0.05) . CONCLUSION: Compared with intraoperative administration alone, prolonged treatment with tranexamic acid after cardiac surgery shows no advantage because it can not further improve coagulant function, reduce bleeding, or reduce allogeneic blood transfusion.

Prevalence and risk factors of chronic post-thoracotomy pain in Chinese patients from Peking Union Medical College Hospital.

BACKGROUND: In clinical practice, the mechanisms underlying chronic post-surgical pain (CPSP) remain insufficiently understood. The primary goals of this study were to determine the incidence of chronic pain after thoracic surgery and to identify possible risk factors associated with the development of chronic post-thoracotomy pain in Chinese patients. The secondary goal was to determine whether the difference between pre- and post-operative white blood cell (WBC) counts could predict the prevalence of CPSP after thoracotomy. The impact of chronic pain on daily life was also investigated. METHODS: We contacted by phone 607 patients who had undergone thoracotomy at our hospital during the period February 2009 to May 2010. Statistical comparisons were made between patients with or without CPSP. RESULTS: were ultimately analyzed from 466 qualified patients. The overall incidence of CPSP was 64.5%. Difference between pre- and post-operative WBC counts differed significantly between patients with or without CPSP (P < 0.001) and was considered as an independent risk factor for the development of CPSP following thoracotomy (P < 0.001). Other predictive factors for chronic pain included younger age (< 60 years, P < 0.001), diabetes mellitus (P = 0.023), acute post-operative pain (P = 0.005) and the duration of chest tube drainage (P < 0.001). At the time of interviews, the pain resulted in at least moderate restriction of daily activities in 15% of the patients, of which only 16 patients had paid a visit to the doctor and only three of them were satisfied with the therapeutic effects. CONCLUSIONS: Chronic pain is common after thoracotomy. WBC count may be a new independent risk factoring surgical patients during peri-operative period. Besides, age, diabetes mellitus, acute post-operative pain, and duration of chest tube drainage may also play a role in chronic post-surgical pain occurrence.

[Analgesic effect of calpain inhibitor ALLN on the zymosan-induced paw inflammatory pain and its effect on the expression of cyclooxygenase-2 in the spinal dorsal horn].

OBJECTIVE: To examine the analgesic effect of calpain inhibitor ALLN on the zymosan-induced paw inflammatory pain and its effect on the expression of cyclooxygenase-2 (COX-2) in the spinal dorsal horn. METHODS: Forty-eight Sprague-Dawley rats were equally divided into three groups: control group, sham-operated group, and zymosan group. According to Meller's method, zymosan (1.25 mg) was injected intraplantarly to induce paw inflammation in zymosan group; an equal volume of PBS was administered in the sham-operated group. Mechanical withdrawal threshold (MWT) and maximum thickness of paw were tested or measured before and 0.5, 1, 2, 4, 8, and 24 hours after injection. All rats were killed at different occasions following surgery to examine calpain activity in the spinal dorsal horn with Western blot analysis. Another sixty-four Sprague-Dawley rats were divided into three groups: sham-operated group, zymosan-induced paw inflammation with intraperitoneal dimethyl sulphoxide (DMSO) treatment group, and zymosan-induced paw inflammation with intraperitoneal calpain inhibitor ALLN treatment group. MWT and maximum thickness of paw were tested or measured before and 0.5, 1, 2, 4, 8, and 24 hours after injection. All rats were killed at different occasions following surgery to examine the COX-2 expression in the spinal dorsal horn with Western blot analysis. RESULTS: MWT significantly decreased in the rats with zymosan-induced paw inflammation, while the maximum thickness of paw significantly increased, compared with control and sham-operated rats (P < 0.05). Calpain in the ipsilateral spinal dorsal horn was dramatically activated after zymosan injection (P < 0.01). Intraperitoneal ALLN injection significantly increased zymosan-induced MWT and decreased paw edema at the same time points after zymosan injection compared with DMSO treatment group (P < 0.05). Meanwhile, calpain inhibitor ALLN treatment significantly decreased the COX-2 expression in the spinal dorsal horn compared with DMSO treatment (P < 0.01). CONCLUSION: Administration of calpain inhibitor ALLN is effective to attenuate zymosan-induced paw inflammatory pain. Calpain activation may be one aspect of the signaling cascade that increases the COX-2 expression in the spinal cord and contributes to mechanical hyperalgesia after peripheral inflammatory injury.

[Application of propofol target controlled infusion combined with dribbled and nebulized lidocaine in tracheal intubation under spontaneous respiration].

OBJECTIVE: To evaluate the value of propofol target-controlled infusion combined with dribbled and nebulized lidocaine in tracheal intubation under spontaneous breathing. METHODS: Totally 40 elective surgery patients to accept tracheal intubation under unconsciousness and spontaneous breathing were randomly divided into 2 groups: 6-8 cm of endotracheal tube was inserted subglottic ally in the complete intubation group (n=20) while 3-4 cm was inserted temporarily in the partial intubation group (n=20). RESULTS: The tracheal intubation was successfully completed under spontaneous breathing in all patients; meanwhile,the hemodynamic status was stable without any severe respiratory complications. Eleven patients suffered from moderate coughing response in the complete intubation group while no such response was noted in the partial intubation group (P<0.01). CONCLUSIONS: Application of propofol target-controlled infusion combined with dribbled and nebulized lidocaine provides a good condition for tracheal intubation under unconsciousness and spontaneous breathing. The partial intubation can effectively prevent the occurrence of coughing response.

[Application of lumber plexus blockade for hip fracture repair in elderly patients].

OBJECTIVE: To evaluate the lumber plexus blockade as anesthesia technique for hip fracture repair in elderly patients. METHODS: We retrospectively analyzed the peri-operative data of 87 hip fracture patients, aged 70 years or older, who underwent surgical repair at our hospital between 2003 and 2006. Patients were divided into three groups according the anesthesia techniques applied: general anesthesia (GA) group (n=21), epidural anesthesia (EA) group (n=37), and lumber plexus blockade (LPB) group (n=29). RESULTS: The peri-operative data were comparable among three groups, except that intra-operative the dosage of fentanyl was significantly lower in LPB group compared with in GA group(P0.05), and the blood urea nitrogen 1 day after surgery was significantly increased in GA group(P0.05). CONCLUSION: Lumber plexus blockade combined with small-dose intravenous anesthesia is an optional anesthetic technique for elderly patients undergoing hip fracture repair.

Clinical features and diagnosis for Chinese cases with malignant hyperthermia: a case cluster from 2005 to 2007.

BACKGROUND: Malignant hyperthermia (MH), manifesting as MH crisis during and/or after general anesthesia, is a potentially fatal disorder in response to volatile anesthetics and depolarizing muscle relaxants. Though typical features of MH episode can provide clues for clinical diagnosis, MH susceptibility is confirmed by in vitro caffeine-halothane contracture test (CHCT) in western countries. It is traditionally thought that MH has less incidence and fewer typical characteristics in Chinese population than their western counterparts because of the different genetic background. In this study, we investigated the clinical features of MH in Chinese cases and applied the clinical grading scale and CHCT for diagnosis of MH. METHODS: A cluster of three patients with MH, from January 2005 to December 2007, were included in the study. Common clinical presentations and the results of some lab examinations were reported in detail. The method of the clinical grading scale of diagnosis of MH was applied to estimate the qualitative likelihood of MH and predict MH susceptibility. Muscle fibers of femoral quadriceps of the patients were collected and CHCT was performed to confirm the diagnosis of MH. RESULTS: The clinical grading scales of diagnosis of the disease for these cases were all ranked grade D6, suggesting almost diagnosed ones. And the results of caffeine test were positive correspondingly, indicating that the patients should be diagnosed as MH susceptibility (MHS) according to diagnostic criteria of the North America MH group, which were already confirmed by clinical presentations and biochemical results. CONCLUSIONS: These Chinese cases manifest as MH crisis. The clinical grading scale of diagnosis of MH may provide clues for clinical diagnosis. CHCT can also be used in confirming diagnosis of MH in Chinese cases though they have different genetic background from their western counterparts.

[Effects of residual paralysis after a single intubating dose of rocuronium on postoperative pulmonary function of patients undergoing laparoscopic gynecological surgeries].

OBJECTIVE: To evaluate the residual paralysis after a single intubating dose of rocuronium and its effect of residual paralysis after a single dose of rocuronium on the postoperative pulmonary function of patients undergoing laparoscopic gynecological surgeries. METHODS: Sixty American Society of Anesthesiologists (ASA) I - II patients undergoing laparoscopic gynecological surgeries were randomly divided into rocuronium (R) group (n = 30) and rocuronium + neostigmine (R + N) group (n = 30).All patients received midazolam (0.02 mg/kg), fentanyl (1 microg/kg), propofol(1.5-2 mg/kg), and rocuronium (0.6 mg/kg) to facilitate tracheal intubation and no more relaxant thereafter. Anesthesia was maintained with isoflurane and nitrous oxide in oxygen (N(2)O:O(2) = 1:1). At the end of the procedure, neuromuscular blockade was not reversed in R group, while antagonism was accomplished with neostigmine (0.04 mg/kg) and atropine (0.02 mg/kg) in R + N group. Immediately after tracheal extubation and on arrival in the PACU, the train-of-four (TOF) ratio at the adductor pollicis of all patients were measured using acceleromyography. Forced vital capacity (FVC), forced expiratory volume in one second (FEV(1)), and peak expiratory flow rate (PEFR) of all patients were measured using spirometry before surgery, after administration of midazolam and fentanyl, immediately after tracheal extubation, on arrival in the PACU, and after the TOF ratio recovered to 1.0. The TOF ratio and pulmonary function between two groups were compared. RESULTS: Immediately after tracheal extubation and on arrival in the PACU, the mean TOF ratio in R group was significantly lower than that in R + N group (P < 0.05). The mean time to achieve TOF ratio of 0.9 and 1.0 in R group was significantly longer than in R + N group (P < 0.05). Immediately after tracheal extubation and on arrival in the PACU, FVC, FEV(1), and PEFR were significantly lower in R group than in R + N group (P < 0.05). FVC, FEV(1), and PEFR after administration of midazolam and fentanyl and after TOF ratio recovered to 1.0 were significantly lower than the baseline values in all patients (P < 0.01). CONCLUSIONS: After a single intubating dose of rocuronium, residual paralysis exists in the majority of patients undergoing laparoscopic gynecological surgeries. The pulmonary function is impaired after the surgery, even after recovery of TOF ratio to 1.0.

[Perioperative hemodynamics in pheochromocytoma secreting different types of catecholamine].

OBJECTIVE: To analyze the characteristics of perioperative hemodynamics in pheochromocytoma secreting different types of catecholamine, and to discuss how to improve the hemodynamics. METHODS: The clinical data of 202 patients with pheochromocytoma who had received operation were analyzed. Three classification systems were used to divided the patients: they were, firstly, divided into high and low epinephrine secreting groups (E(high) and E(low)) according to the 24 hours urine catecholamine quantitation; secondly, into high and low norepinephrine secreting groups (NE(high) and NE(low)) according to 24-h urine norepinephrine quantitation; and thirdly, into high and low dopamine secreting groups (DA(high) and DA(low)) according to the 24 hours urine dopamine quantitation. Relationship between the characteristics of perioperative hemodynamics and catecholamine secreting types were analyzed. RESULTS: The highest preoperative systolic blood pressure values of E(high) and NE(high) groups were (201 +/- 40) mm Hg and (205 +/- 38) mm Hg, both significantly higher than those of the E(low) and NE(low) groups [(183 +/- 43) mm Hg, P = 0.003 and (181 +/- 43) mm Hg, P = 0.000]. The range of systolic blood pressure fluctuation during the operation of the E(high) group was 108 +/- 39 mm Hg, significantly larger than that of the E(low) group (91 +/- 33 mm Hg, P = 0.001). The incidence rates of persisting postoperative hypotension of the NE(high) and DA(high) groups were 23.3% (20/86) and 32.7% (17/52) respectively, both higher than those of the NE(low) and DA(low) groups [2.6% (3/116) and 4.0% (6/150) respectively, P = 0.000 and P = 0.000]. CONCLUSION: Different characteristics of perioperative hemodynamics are present in pheochromocytoma secreting different types of catecholamines. Patients with highly epinephrine secreting pheochromocytoma are apt to have larger blood fluctuation during the operation. Patients with highly norepinephrine and dopamine secreting pheochromocytoma are apt to suffer from persisting postoperative hypotension.

[Application of caffeine-halothane contracture test in the diagnosis of malignant hyperthermia].

OBJECTIVE: To explore the application of caffeine-halothane contracture test (CHCT) in the confirmation of malignant hyperthermia (MH). METHODS: One patient who underwent radical gastrectomy presented with clinical manifestations of MH during routine intravenous-inhalation anesthesia process. Isoflurane inhalation and the operation were ceased immediately and emergency management approaches such as physical cooling therapy were taken. Meanwhile, the levels of serum creatine kinase (CK), serum myoglobin, and urinary myoglobin were examined and rectus abdominis was taken and then CHCT was performed to confirm the clinical diagnosis. Total genome was extracted from the patient and then exons 2-18, 39-46, and 90-104 of ryanodine receptor 1 (RYR1) gene were screened to detect mutations using DNA sequencing technique. RESULTS: The patient was diagnosed as MH episode by clinical characteristics and postoperatively continuous elevation of the levels of CK, serum myoglobin, and urinary myoglobin (30 times higher than normal level). Despite halothane test was negative, the diagnosis of MH was verified by the positive result of caffeine test. DNA sequencing of RYR1 gene of the patient revealed c. 6724C > T (p. T 2 206M). CONCLUSION: CHCT can be used to confirm the diagnosis of MH.

Postoperative neuropsychological change and its underlying mechanism in patients undergoing coronary artery bypass grafting.

BACKGROUND: The high incidence of neuropsychologic deficits after cardiac surgery, including cognitive dysfunction and mood status, has significantly influenced the prognosis, outcome of treatment and long-term quality of life of patients. With a circadian secretion pattern, melatonin and cortisol are capable of modulating the human physiological processes and neuropsychological status, whereas disorder of their secretion pattern may lead to many diseases. However, it is unclear whether neuroendocrine variations are related to the neuropsychologic status in patients undergoing coronary artery bypass grafting (CABG). METHODS: Forty male patients scheduled for CABG with hypothermic cardiopulmonary bypass (CPB) (n = 20) or off-pump coronary artery bypass (OPCAB) (n = 20) were studied. Blood samples were taken intraoperatively at specific time-points and every 3 hours within the first postoperative 24 hours to determine plasma concentrations of melatonin and cortisol. A neuropsychologic test battery including depression and anxiety was administered preoperatively and 7 to 10 days postoperatively. Statistical methods included the nonparametric analysis, multiple linear regression and cosinor analysis. RESULTS: The patients in the CPB group exhibited more severe neuropsychologic deficits and more anxious than those in the OPCAB group after surgery. In both groups, patients were more depressed postoperatively than preoperatively and recovered 3 months after surgery. Depression and anxiety were correlated with some factors of cognitive dysfunctions. In the postoperative 24 hours, 2 patients in the CPB group, and 6 patients in the OPCAB group showed a circadian rhythm of melatonin secretion. As for cortisol secretion, there were 3 patients in the CPB group and 7 in the OPCAB group respectively. Parameters of circadian rhythm of melatonin in the CPB group and those of secretion rhythm of cortisol in both groups were correlated with depression and some neuropsychologic tests. CONCLUSIONS: The incidence of neuropsychological deficits was higher in patients receiving CABG with CPB than in those without CPB. The status of mood may contribute to the perioperative cognitive dysfunctions. The disordered circadian rhythm of melatonin secretion in patients undergoing CABG with CPB and the disordered cortisol secretion may correlate directly or indirectly through mood with neuropsychological deficits.

Malignant hyperthermia in China.

Malignant hyperthermia has rarely been reported in China. We report the first case of malignant hyperthermia, verified by caffeine-halothane contracture test and genetic testing, in a Chinese patient.

[Anesthetic management of laparoscopic adrenalectomy for pheochromocytoma].

OBJECTIVE: To investigate the anesthetic management features of laparoscopic adrenalectomy for pheochromocytoma. METHODS: Twelve patients scheduled for laparoscopic adrenalectomy for pheochromocytoma under general anesthesia were allocated into group 1, while another 12 patients who received transabdominal adrenalectomy for pheochromocytoma under general anesthesia were selected as group 2. The hemodynamic changes and the postoperative recovery profiles between the two groups were compared. RESULTS: Hemodynamic fluctuation occurred during carbon dioxide insufflation and tumor manipulation in group 1. However, there were no differences between the two groups. Duration of post operative recovery and hospital stay as well as requirement of analgesics in group 1 were significantly lower than those in group 2 (P < 0.05). CONCLUSION: Hemodynamic fluctuation still exists during laparoscopic adrenalectomy for pheochromacytoma. However, patients undergoing such surgical procedure recover faster as compared with open surgery.

[Perioperative cortisol circadian secretion and neuropsychological states in patients undergoing coronary artery bypass grafting surgery].

OBJECTIVE: To investigate the relationship between the circadian rhythm of perioperative cortisol secretion and neuropsychological states in patients undergoing coronary artery bypass grafting surgery. METHODS: Forty male patients scheduled for elective coronary artery bypass grafting (CABG) under hypothermic cardio-pulmonary bypass (CPB) or off-pump were enrolled in this study. They were allocated into CPB group or off-pump group with 20 patients in each group. Blood samples were withdrawn during surgery at specific time-points and every 3 h for 24 h in the immediate postoperative period. Plasma cortisol was measured by radioimmunoassay. All subjects were investigated preoperatively as well as 7 to 10 d and 3 months postoperatively with a comprehensive neuropsychologic assessment, while depression and anxiety were assessed by Self-Rating Depression Scale and the State-Trait Anxiety Inventory respectively. RESULTS: During postoperative 24 h, three patients in the CPB group and 7 patients in the off-pump group were demonstrating a circadian secretion pattern, while they were disturbed in the remaining patients in both groups. Postoperative depression scores of patients in both groups were significantly higher than preoperative values. Postoperative anxiety scores of patients in the CPB group were significantly higher than those in the off-pump group. The CABG with CPB patients showed a significant deficit in the Digit Span subtest of the WAIS-R and the Stroop colour word interference test. The disturbed cortisol circadian secretion in the CPB group correlated with depression and the Stroop colour word interference test, whereas in the off-pump group it correlated with depression, Digit Span subtest (forward), symbol digit modalities test and the Stroop colour word interference test. Degree of depression correlated with some items of cognitive dysfunctions. CONCLUSION: Perioperative secretion rhythm of cortisol in patients undergoing CABG surgery with CPB or off-pump was disturbed. The disordered cortisol may correlate directly or indirectly through mood with neuropsychological deficits.

Forced-air warming and fluid warming minimize core hypothermia during abdominal surgery.

OBJECTIVE: To evaluate the effect of intraoperative combined forced-air warming and fluid warming system on patient's core temperature, blood loss, transfusion demand, extubation time, and incidence of postoperative shivering. METHODS: Forty patients with American Society of Anesthesiologists physical status I and II, aged 18-70 years, scheduled for elective abdominal surgery were randomly assigned to receive intraoperative warming from a forced-air blanket and fluid warming system or conventional cotton blanket, 20 in each group. The core temperature was recorded every 20 minutes during the operation, as well as the blood loss, blood transfusion, extubation time, and incidence of postoperative shivering. RESULTS: The core temperature at the end of the surgery in the warming group was significantly different from that in the control group (36.4 +/- 0.4 degrees C vs. 35.3 +/- 0.5 degrees C, P < 0.001). Application of intraoperative warming significantly shortened the time between the end of the surgery and extubation (P < 0.01). Postoperative shivering occurred in 30% of the patients in the control group compared to no patient in the warming group (P < 0.01). CONCLUSION: Active warming with air-forced blanket and fluid warming system provides sufficient heat to prevent hypothermia during abdominal surgery.

[The effect of intraoperative warming on patient core temperature].

OBJECTIVE: To investigate the influence of using fluid warming and forced-air warming system on patient core temperature, blood loss, blood transfusion, extubation time, and postoperative shivering. METHODS: Forty ASA (American Society of Anesthesiologists' Physical Status) I-II patients, aged 21-69 years, scheduled for elective abdominal surgery under general anesthesia, were enrolled in the study. The patients were premedicated with intramuscular dolantin 50 mg and atropine 0.5 mg. Anesthesia was induced with midazolam 1 mg, fentanyl 50-100 microg and propofol 1.5-2.0 mg/kg. Tracheal intubation was facilitated with vecuronium 1mg and succinylcholine 1.5-2.0 mg/kg. The patients were mechanically ventilated and anesthesia was maintained with isoflurane 1.5-2.0%, 50% N2O in oxygen and intermittent iv boluses of fentanyl (total dose 5-6 microg/kg). Vecuronium was used for muscle relaxation during maintenance of anesthesia. The patients were randomly divided into 2 groups: control group (n = 20) and warming group (n = 20). In both groups, the patients were covered with surgery blanket. In the warming group, patients were additionally warmed with fluid warming device and forced-air warming system during the operation. The core temperature was recorded every 20 minutes during the operation, as well as the blood loss, blood transfusion, extubation time and postoperative shivering. RESULTS: The core temperature at the end of the surgery was (36.4 +/- 0.4) degrees C in the warming group and (35.3 +/- 0.5) degrees C in the control group. The difference was statistically significant (t = 7.547, P < 0.001). There was no significant difference of blood loss and blood transfusion between two groups. The extubation time was significantly shorter in the warming group [(18 +/- 6) vs (26 +/- 10) min, t = -3.364, P = 0.002]. 6 patients shivered postoperatively in the control group and none in the warming group (chi2 = 7.059, P = 0.008). CONCLUSION: Fluid warming system and forced-air warming system can effectively maintain normothermia during the surgery and then help to reduce the extubation time and postoperative shivering.

[Effect of intraoperative using cell saver on blood sparing and its impact on coagulation function].

OBJECTIVE: To observe the effectiveness of using cell saver (CS) during surgery on blood sparing and its impact on patient's hematology and coagulation function. METHODS: One-hundred and thirty-eight patients undergoing elective surgery were recruited for intraoperative blood salvage using CS. Blood routine, blood chemistry and coagulation function were measured before surgery, after infusion of salvaged blood and postoperative day 1, respectively. RESULTS: In total, 112,056 ml of packed red blood cells were collected, with a mean value of 812 ml per patient. The percentage of autologous blood transfusion volume to the total blood transfusion volume was from 48% to 89%. Allogenic blood transfusion rate was from 5% to 100%. Compared with the values before surgery, the hemoglobin concentration, platelet count, plasma total protein and fibrinogen concentration decreased significantly after the transfusion of salvaged blood and the first postoperative day (P < 0.05 or P < 0.01), while the prothrombin time was significantly prolonged (P < 0.05). CONCLUSIONS: The use of CS during surgery can, to a certain extent, reduce the requirement of allogenic blood. However, reinfusion of large amount of salvaged blood may affect coagulation function.

[Perioperative melatonin circadian secretion in patients undergoing coronary artery bypass grafting surgery].

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.