[A proteomic study of peripheral blood mononuclear cells in patients undergoing cardiopulmonary bypass].

OBJECTIVE: To explore the effect of cardiopulmonary bypass (CPB) on the profile of protein expression in peripheral blood mononuclear cells (PBMCs). METHODS: Eleven patients undergoing cardiac surgery under cardiopulmonary bypass were enrolled in the study. Peripheral blood samples were collected before CPB (T0), 1 h after CPB (T1) and at the end of operation (T2), and PBMCs were obtained by gradient centrifugation. The profile of protein expression was analyzed using 2-D gel electrophoresis (2-DE) and mass spectrometry. The candidate proteins were further identified by Western blotting. RESULT: Compared to protein profile at T0, 12 protein spots were identified to be up-regulated in PBMCs at T1 (P <0.05), among which S100A9 reached the peak level at T1 and decreased after operation,but not returned to its initial level. CONCLUSION: Results indicate that 12 proteins are likely to be involved in CPB, however, their roles need to be elucidated.

[Effects of penehyclidine hydrochloride or atropine combined with neostigmine for antagonizing residual neuromuscular block on patient's hemodynamics].

OBJECTIVE: To investigate the effects of penehyclidine hydrochloride(PH)/atropine combined with neostigmine for antagonizing residual neuromuscular block on the hemodynamics. METHODS: Eighty patients with elective upper abdominal surgery were randomized equally into PH group and atropine group. Five minutes after the completion of surgery, PH 0.02 mg/kg (in PH group) or atropine 0.02 mg/kg (in atropine group) in combination with neostigime 0.03 mg/kg were given intravenously to reverse the residual neuromuscular block. The heart rate (HR), mean arterial pressure (MAP) and end-tidal CO(2) pressure (P(ET)CO(2)) were recorded 5 min before anesthesia induction, 1 min before injection and 2, 5, 10, and 15 min after injection, respectively. RESULTS: During the investigation, HR in PH group did not undergo conspicuous changes (P>0.05). HR after the injection was markedly faster than that before the injection in atropine group (P<0.01) and did not recover till 15 min after the injection (P>0.05). MAP and P(ET)CO(2) showed no evident changes and no significant difference was observed between the two groups during the investigation (P>0.05). CONCLUSION: Compared with atropine, PH does not obviously affect HR and BP, but atropine may accelerate HR.

[Effects of fentanyl on EC50 of ropivacaine for postoperative epidural analgesia after gynecological surgery].

OBJECTIVE: To determine the effect of fentanyl on 50% effective concentration (EC50) of ropivacaine for postoperative epidural analgesia following gynecological surgery. METHODS: Sixty-five patients (ASA class I to II) scheduled for elective gynecological surgery were randomly divided into two groups to receive 20 ml ropivacaine (group R, n=33) or ropivacaine combined fentanyl (group RF, n=32) for postoperative epidural analgesia. The concentration of ropivacaine was adjusted according to double-blinded up-down sequential allocation. The efficacy was assessed using visual analog scores (VAS) and EC50 calculated using method of Dixon. RESULTS: The EC50 of ropivacaine was 0.098% in group R and 0.069% in group RF, showing significant difference (P<0.01). CONCLUSION: EC50 of ropivacaine for postoperative epidural analgesia determined by up-down sequential allocation is 0.098%, which can be decreased by the use of fentanyl.

[Determination of EC50 of ropivacaine and bupivacaine for postoperative epidural analgesia by up-down sequential allocation].

OBJECTIVE: To determine the median effective concentration (EC50) of ropivacaine and bupivacaine for postoperative epidural analgesia, and compare the efficacy of the 2 analgesics. METHODS: Sixty-five patients (ASA I to II) scheduled for elective gynaecological surgeries were randomly assigned into ropivacaine and bupivacaine groups to receive postoperative epidural analgesia with the indicated analgesics (20 ml). The concentration was determined by the response of a previous patient to a higher or lower concentration using double-blinded, up-down sequential allocation. The analgesic efficacy was assessed with 100 mm visual analog pain scores (VAS), and effectiveness was defined as having a VAS

[Management of hyperkalemia-induced cardiac arrest in anhepatic stage of orthotopic liver transplantation without venovenous bypass: report of 3 cases].

The causes of high serum potassium-induced cardiac arrest in anhepatic stage of orthotopic liver transplantation were analyzed in 3 cases without venovenous bypass, and the effectiveness of insulin was evaluated in correcting hyperkalemia during the anhepatic stage. To improve the survival rate of patients with such cardiac arrest, early cardiopulmonary resuscitation and timely defibrillation should be performed.

[Respiratory distress syndrome induced by immersion in seawater: a study of canine models].

OBJECTIVE: To study the mechanism of respiratory distress syndrome (RDS) induced by immersion in seawater to provide experimental evidence for its treatment. METHODS: Twelve normal hybrid dogs were randomly assigned into control group (n=4) and SDS model group (n=8). The changes in blood dynamics, blood gas analysis and histological changes in the lung tissues were compared between the 2 groups. The concentration of lactic dehydrogenase (LDH-L) and alkaline phosphatase (ALP) in the bronchoalveolar fluid and blood of the dogs in the model group were tested. RESULTS: The blood dynamics, blood gas analysis and histology of the dogs in the model group were significantly different from those in the control group, and LDH-L and ALP levels increased significantly in the bronchoalveolar fluid of the model group. CONCLUSION: Seawater aspiration into the lungs may lead to RDS, and the canine models used in this study may help explore the mechanism and management of RDS induced by immersion in seawater.

[Treatment of acute lung injury due to sea water aspiration in dogs by early massive bronchoalveolar lavage: an experimental study].

OBJECTIVE: To investigate the therapeutic effects of massive bronchoalveolar lavage at early stage of acute lung injury induced by sea water aspiration. METHODS: Twelve mongrel dogs were subjected to sea water infusion of the entire lungs and were subsequently randomized into 2 groups. The dogs in group A received intravenous saline transfusion 24 h after injury, while those in group B underwent bronchoscopic lavage of injured lungs with 450 ml 0.45% saline 15 min after injury. Unassisted breathing was maintained in both groups, and the gas exchange function of the bilateral lungs and the levels of lactate dehydrogenase, alkaline phosphatase in the bronchoalveolar fluid were observed, with the hemodynamics indices monitored continuously. The lungs of the dogs were finally removed for morphological study under both light and electron microscopes, and the water content and wet- to dry-weight ratio of the lung tissues were determined. RESULTS: A total lavage volume of approximately 30 ml/kg x b.w. was used, and the liquid volume remaining in the lungs after operation ranged from 80 to 120 ml. All the dogs manifested significant declination in pulmonary function after the drowning. PaO2 in group B decreased significantly soon after the lavage but then increased gradually to a higher levels than group A. The dogs in group B had smaller lung water content and lower levels of lactate dehydrogenase and alkaline phosphatase in the bronchoalveolar fluid, showing improved oxygenation in comparison with group A. The inflammatory reaction and edema in lungs were also markedly alleviated in group B. CONCLUSION: Treatment with massive lung lavage in early stage after sea water aspiration can effectively protect the lung tissues from damage and alleviate the inflammatory reaction and pulmonary edema, helping to improve the lung function.

[Changes of oxygen cost of breathing in children and adult during anesthesia and surgery].

OBJECTIVE: To investigate the changes of oxygen cost of breathing (OCB) in children and adult during general anesthesia and surgery. METHODS: This study included 12 elective surgical children and 12 adult patients receiving cerebral surgery. Mechanical ventilation was given during general anesthesia and surgery, and the indices of hemodynamics and respiratory function were measured at 5 min before induction, 1 min before the start of surgery, 30, 60, 120 and 180 min after the start of surgery and at the end of surgery, respectively. RESULTS: Mean arterial pressure (MAP) in the 2 groups did not undergo any conspicuous changes during general anesthesia and surgery (P>0.05), and the heart rate in child group was markedly faster than that in adult group during the whole course (P<0.01). Oxygen consumption (VO2) in 2 groups at 1 min before the start of surgery and 30 min after the start of surgery was significantly higher than that at 5 min before induction (P<0.01), and at these two time points after induction, child group had much higher VO2 (P<0.05) but evidently lower OCB (P<0.01) than in adult group, the latter index remained low till 60 and 120 min after the start of surgery (P<0.05). CONCLUSION: During anesthesia and surgery, VO2 in child group can be much greater than that in Adult group, while OCB markedly lower.

[Ropivacaine or its combination with fentanyl for postoperative patient-controlled epidural analgesia].

OBJECTIVE: To investigate the pain-relieving effects of ropivacaine or its combination with fentanyl in postoperative patient-controlled epidural analgesia. METHODS: Sixty patients (ASA class I to II) scheduled for elective upper abdominal surgery were randomly divided into 4 groups (15 in each group) to receive 2.0 mg/ml ropivacaine (group R), 1.25 mg/ml ropivacaine plus 1.0 microg/ml fentanyl (group RF1), 1.0 mg/ml ropivacaine plus 2.0 microg/ml fentanyl (group RF2), and 1.0 mg/ml ropivacaine plus 4.0 microg/ml fentanyl (group RF4) respectively for patient-controlled analgesia. The bolus injection was set at 3.0 ml, lockout interval at 20 min, and background epidural infusion at 5.0 ml/h. Before and at 0, 6, 12, 24 and 48 h after the surgeries, the data including mean arterial pressure (MAP), heart rate (HR), cumulative consumption volume (CCV) of analgesic solution and visual analog scale (VAS) scores were recorded, observed and the adverse effects such as vomiting, nausea, pruritus, as well as the time of first excretion of intestinal gas. RESULTS: Compared with group R, significantly smaller CCV occurred in groups RF2, RF4 (P<0.01), and RF1 (P<0.05) at each time points postoperatively. No significant differences were noted between the groups in VAS scores. CONCLUSION: The 4 preparations are comparable in terms of analgesic efficacy and adverse effects, but in groups RF2 and RF4, the smaller doses have sufficed the needs.

Study of direct lung injury by seawater in canine models.

OBJECTIVE: To study the mechanism of direct lung injury by seawater and explore its possible management. METHODS: To exclude the interference of hypoxia and acidosis during the study of seawater-induced direct lung injury, 18 normal hybrid dogs were randomly assigned into group A (with all lung lobes perfused with seawater), group R (with the right lung lobe perfused with seawater) and group D (with the diaphragmatic lobe of lung perfused with seawater), with 6 dogs in each group. The changes in blood gas dynamics, blood gas acid-base status and electrolytes, along with the histological changes in the lung tissues were comparatively analyzed between the 3 groups. Bronchial microscope was employed to observe the continuous changes in the bronchioles before and after seawater perfusion in group D, and the concentration of the bronchoalveolar fluid and blood LDH-L and ALP levels were tested. RESULTS: The values of PaO(2), PaCO(2), pH, actual bicarbonate (AB), base excess (BE), tidal volume, and respiration rate in groups A and R were significantly different from those in group D (P < 0.01), and in groups A and R, the above measurements at every stage after seawater perfusion were significantly different from those before perfusion (P < 0.01). In group D, however, blood gas dynamics, blood gas acid-base status and electrolytes changed little after seawater perfusion (P > 0.05). In all the groups, obvious lung tissue injuries were observed under optical microscope after seawater perfusion. Observation with electron microscope revealed injuries to type II alveolar epithelial cells, broadened respiratory mucosa, and platelet adherence. Bronchial microscope in group D presented the bronchus filled with bronchoalveolar fluid, and blood LDH-L and ALP levels kept rising significantly (P < 0.01). Within 4 h after seawater perfusion, no pathological changes were seen in the lung tissues without direct contact with seawater. CONCLUSIONS: Seawater inspiration and retention in the lungs may lead to severe direct lung injury, and is the primary factor responsible for acute lung injury after drowning in the sea.

[Intravenous injection rate and site of fentanyl affect the incidence and onset time of fentanyl-induced cough].

OBJECTIVE: To explore the effect of intravenous injection rate and site of fentanyl on the incidence and onset time of fentanyl-induced cough. METHOD: Seventy-five ASA class I or II patients were randomized into 3 groups and received intravenous fentanyl administration at 4 microg/kg in different manners. In group A, fentanyl was injected within 2 s into the forearm veins; in group B, fentanyl was injected in 2 s through the dorsal foot veins or the great saphenous vein anterior to the ankle; in group C, fentanyl was injected in 15 s by the same route as in group A. RESULTS: The incidence of cough was 44%, 52% and 8%, with cough onset time of 16.1-/+2.7 s, 21.9-/+3.7 s and 23.3-/+3.2 s in groups A, B and C, respectively. Compared with group A, group B had a delayed onset of cough (P<0.05), and group C had both a lowered incidence of cough (P<0.05) and delayed onset of cough (P<0.05). CONCLUSIONS: The rate of fentanyl injection through the same peripheral venous access at the same dose may affect the incidence and onset time of cough. At the same dose and injection rate of fentanyl, forearm venous access of injection resulted in earlier onset of cough than lower limb venous access, but the incidence is similar.

[Low-dose ketamine combined with fentanyl for intravenous postoperative analgesia in elderly patients].

OBJECTIVE: To investigate the clinical efficacy of and complications arising from low-dose ketamine combined with fentanyl for intravenous postoperative analgesia in comparison with the exclusive use of fentanyl in elderly patients. METHODS: Eighty elderly patients were randomized into two equal groups following thoracoabdominal surgery, and received intravenous analgesia with the combination of 0.5 mg/ml ketamine, 5.0 microg/ml fentanyl and 50 microg/ml midazolam (KF group) and with 7.5 microg/ml fentanyl plus 50 microg/ml midazolam (FT group), respectively. The drugs used were diluted in 200 ml normal saline. For analgesic administration, a loading dose (2-4 ml) was given followed by a background infusion (2.5-3.5 ml), with patient-controlled bolus doses of 2.0-3.0 ml with lock-out time of 20 min via PCA pump (Automedical, Korea). The static pain score (VAS), sedation score, and incidences of nausea, vomiting, pruritus and hallucinations were recorded during the initial 48 h after the surgery. RESULTS: The total analgesic dosage and PCA dosage in the two groups were similar (P>0.05). With similar VAS in the two groups (P>0.05), the sedative effect in KF group was much better than that in FT group (P<0.05) during the initial 48 h postoperatively. The incidences of nausea, vomiting and itching were lower in KF group than in FT group (P<0.05), and no illusion was reported in two groups during the initial 48 h. CONCLUSION: For producing comparable postoperative analgesic effect, low-dose ketamine combined with fentanyl can markedly reduce fentanyl requirement in the elderly patients and lowers the incidences of nausea, vomiting and itching in comparison with the exclusive use of fentanyl.