[IL-6 inhibits colonic longitudinal muscle contraction by inactivating L-type calcium channel in rats with pancreatitis].

The aim of this study was to investigate the effect of interleukin 6 (IL-6) on the contraction of colon longitudinal muscle strips in rats with acute pancreatitis (AP) and its underlying mechanism. Rat AP model was established by combined injection (i. p.) of ceruletide and lipopolysaccharide. The effect of IL-6 on spontaneous contraction of longitudinal smooth muscle strips of rat colon was observed by biological function experiment system. The level of serum IL-6 was detected by ELISA, the expression and distribution of IL-6 in colon were observed by histochemical staining, and the effect of IL-6 on L-type calcium channel in colon smooth muscle cells was observed by whole cell patch clamp technique. The results showed that, compared with the control group, AP group exhibited reduced contractile amplitude and longer contraction cycle of colon smooth muscle strips. IL-6 prolonged the contraction cycle of colon smooth muscle strips, but did not affect their spontaneous contraction amplitude. Serum IL-6 concentration in AP group was significantly higher than that in control group (P > 0.05). IL-6 was diffusely distributed in the colon of the control group, but the expression of IL-6 was significantly up-regulated in the colon gland, mucosa and submucosa of the AP group. IL-6 significantly decreased the peak current density of L-type calcium channel in rat colon smooth muscle cells. These results suggest that the colon motility of AP rats is weakened, and the mechanism may be that up-regulated IL-6 inactivates L-type voltage-dependent calcium channels, and then inhibits the contraction of colon longitudinal smooth muscle.

[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.

[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.

[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.

[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.

[Anesthetic management during resection of intratracheal tumor: report of 23 cases].

OBJECTIVE: To summarize our experience in anaesthetic management during the resection of intratracheal tumor. METHODS: A retrospective analysis of the anaesthetic management was conducted in 23 cases of intratracheal tumor resection. The anaesthetic methods were determined according to the location of tumor, the degree of tracheal obstruction and the surgical procedures. RESULTS: No severe complications occurred in relation to the anesthetic procedures. During the operation, the saturation of pulse oxygen (SpO(2)) transiently decreased to below 90 % in 5 cases (21.7 %) but recovered to normal level by aspiration of airway secretions and/or lung inflation. Seventeen patients (73.9 %) were extubated after the operation and returned to the ward safely, while another 6 (26.1 %) were sent to intensive care unit and extubated within 24 h. CONCLUSION: Case-specific anaesthetic plan is necessary before the operation, and it is crucial to maintain good ventilation without interfering with the surgical procedures during the operation.

Effect of patient-controlled epidural analgesia for pain relief after thymectomy in patients with myasthenia gravis.

OBJECTIVE: To evaluate the effect of patient-controlled epidural analgesia (PCEA) with ropivacaine or bupivacaine in relieving pain after thymectomy in patients with myasthenia gravis. METHODS: Twenty adult ASA I-II patients with myasthenia gravis were randomized to receive either 0.125% ropivacaine (Group R, n=10) or 0.125% bupivacaine (Group B, n=10) with a PCEA device after transsternal thymectomy. PCEA (continuous infusion at 1 ml/h, bolus dose of 4 ml and lockout time of 30 min) was implemented via an epidural catheter inserted in the T3-4 intervertebral space. The vital signs and visual analogue scale (VAS), together with cumulative consumption (CC) of ropivacaine or bupivacaine were recorded within 48 h postoperatively. RESULTS: The vital signs, including systolic and diastolic blood pressure, heart rate, SpO2, pH and PaCO2, did not show any significant differences between the 2 groups. The CC of the local anesthetic was significantly higher in group R than that in group B at 24 and 48 h postoperatively, but VAS were not significantly different between the 2 groups which was less than 4 in both groups. CONCLUSIONS: PCEA with low concentration of ropivacaine or bupivacaine may provide effective and safe analgesia after transsternal thymectomy.

[Effects of intraperitoneal CO2 insufflation on hemodynamics and oxygen consumption during intravenous propofol anesthesia combined with epidural block].

OBJECTIVE: To investigate the effects of intraperitoneal CO2 insufflation on the hemodynamics, oxygen consumption (VO2) and carbon dioxide production (VCO2) during intravenous anesthesia with propofol in combination with epidural block. METHODS: Intratracheal intubation was performed after rapid induction of anesthesia and mechanical ventilation was given. Maintenance of anesthesia was achieved using continuous intravenous propofol infusion (2 mg/kg/h) ?N2O inhalation and intermittent epidural administration. Indices of hemodynamics and respiratory function were collected 5 min before induction, 1 min before CO2 insufflation, and 5, 10, 20, 30, 40, 50, 60 min after the start of insufflation and 5 min after the termination of insufflation. RESULTS: The mean arterial pressure (MAP), heart rate (HR), end-tidal PCO2 (P(ET)CO2), VO2 and VCO2 1 min before insufflation were markedly reduced(P<0.01), compared with those recorded before induction. MAP and HR did not undergo any conspicuous changes during CO2 insufflation and 5 min after insufflation termination. Compared with that 1 min before insufflation, PETCO2 was significantly increased 20 min after the start of insufflation (P<0.01), and subsequently carried on the increase though of a lesser scale. VO2 and VCO2 gradually rose after the start of insufflation, and VO2 presented a significantly elevation (P<0.01) 10 min after the insufflation while VCO2 did not show this marked increase(P<0.05) till 20 min after the insufflation in comparison with the levels before insufflation. Subsequently, VO2 continued to rise and VCO2 also retained the increase but of smaller magnitude. CONCLUSION: Intravenous propofol anesthesia combined with epidural block assisted by well-managed excessive ventilation before insufflation can alleviate the adverse effects of CO2 insufflation on respiratory and circulatory systems.

Effects of patient-controlled upper and lower epidural analgesias on postoperative respiratory and circulatory function.

OBJECTIVE: To compare the effects of patient-controlled high thoracic epidural analgesia (PCHEA) and low thoracic epidural analgesia (PCLEA) on respiratory and circulatory functions after operation. METHODS: Thirty-six patients were divided into 2 groups with 18 in each, and one group (Group H) received PCHEA during thoracic operations and the other (Group L) received PCLEA during abdominal operations. Postoperative patient-controlled analgesia (PCA) was performed in all the patients with 0.125% bupivacaine and 0.01% morphine delivered through the same epidural space for PCHEA or PCLEA. RESULTS: Postoperative analgesia did not produce significant differences in the respiration rate (Rr), tidal volume (Vt), vital capacity (VC) and oxygen saturation (SpO2) between the groups, but in both groups, Vt and VC were significantly improved compared with those before starting patient-controlled epidural analgesia (PECA) (P<0.01). In group H, its effects on systolic and diastolic blood pressure and heart rate were more obvious than in group L (P<0.05), and both groups showed these improvements after PCA started(P<0.01). CONCLUSION: PCHEA shows more marked effects on the respiratory and circulatory functions of the patients, which may mainly result from its blocking the cardiac sympathetic nerves. PCEA is able to improve postoperative respiratory function but both PCHEA and PCLEA necessitate individual-based adjustment of the PCA pump for the safety of the patient.