Establishment of a modified rabbit model of acute lung injury induced by cardiopulmonary bypass / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish an modified rabbit model of the acute lung injury induced by cardiopulmonary bypass (CPB) with ascending aorta and right atrium catheterization and detect the changes in serum tumor necrosis factor-α (TNF-α) level after modeling.</p><p><b>METHODS</b>Ten healthy adult male New Zealand rabbits were randomly selected to establish CPB models. The model establishment was deemed successful if the rabbits survived for over 4 h with stable heart beat after termination of CPB. The vital signs of the rabbits were recorded after anesthesia (T), before CPB (T), at 15 after blocking the ascending aorta and pulmonary artery (T), immediately after re-opening of the ascending aorta and pulmonary artery (T), and at 1 (T) and 4 (T) after CPB. Arterial blood gas (ABG) was monitored at T, Tand Tand the serum levels of TNF-α were also detected with ELISA.</p><p><b>RESULTS</b>Nine rabbit models of CPB with acute lung injury were successfully established. During the operation, the MAP was maintained at a level above 55 mmHg, HCT significantly decreased from (30.18∓2.88)% at Tto (17.73∓1.95)% at T(P<0.05), and plasma lactate level increased significantly from 3.65∓1.13 mmol/L at Tto 9.36∓1.28 mmol/L at T(P<0.05). The oxygenation index (PaO/FiO) at Twas significantly lower than that at T(281.64∓55.76 vs 468.36∓56.28 mmHg, P<0.05). The serum levels of TNF-α were significantly increased (P<0.05) and obvious lung interstitial edema and inflammatory cell infiltration occurred after CPB establishment.</p><p><b>CONCLUSION</b>The modified rabbit model of CPB with acute lung injury is stable and reliable and can be used for studying acute lung injury induced by CPB.</p>

RhoA/Rho-kinase contributes to chronic pain following thoracotomy by up-regulating glutaminase 1 expression in rat spinal dorsal cord / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate whether RhoA/Rho-kinase contributes to the occurrence of chronic post-thoracotomy pain (CPSP) by up regulation of glutaminase 1 (GLS1) expression in the spinal dorsal cord.</p><p><b>METHODS</b>Twenty five male Sprague Dawley (SD) rats were divided into control group (n=5) and model group (n=20). The rats in the model group were randomized into two sub groups (n=10) for observation on day 10 and day 21 after thoracotomy, and each group was further divided into CPSP and non CPSP groups according to the behavioral test results. All the rats were sacrificed after behavioral test for examination of GLS1 and RhoA expressions in the spinal cord using Western blotting and RT PCR. We also compared the effect of the Rho kinase inhibitor fasudil and saline, both injected intraperitoneally daily at 10 mg/kg for 7 consecutive days following thoracotomy, on CPSP and GLS1 expression in 30 male SD rats on day 21 after thoracotomy.</p><p><b>RESULTS</b>Compared with the control group, the rats with CPSP showed significantly increased expressions of GLS1 and RhoA mRNA in the spinal cord on both day 10 and day 21 following thoracotomy (P<0.01), but the rats without CPSP did not show obvious changes in GLS1 and RhoA expressions. In fasudil treated rats, the mechanical pain threshold was obviously increased and the expressions of GLS1 and RhoA were significantly reduced as compared with those in saline treated rats (P<0.01).</p><p><b>CONCLUSION</b>RhoA plays an important role in the occurence of CPSP by up-regulating the expression of GLS1 in the spinal dorsal cord of rats.</p>

Effect of mean arterial pressure on arterial to end-tidal CO₂partial pressure difference during one-lung ventilation / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effect of different mean arterial pressures (MAP) on arterial to end-tidal CO₂partial pressure difference [(Pa-et)CO₂] and the intrapulmonary shunt (Qs/Qt) in patients undergoing thoracic surgery during one-lung ventilation (OLV).</p><p><b>METHODS</b>Forty-two patients undergoing right-sided pulmonary lobectomy were allocated into group A with fluctuation of MAP (at 20 min after OLV) within ± 10% of the baseline (n=22) and group B with lowered MAP by 30% of the baseline (n=20). Arterial and venous blood gas analyses were recorded to calculate [(Pa-et)CO₂] and Qs/Qt at 20 min after induction with two-lung ventilation (T₁), 20 min after OLV (T₂), 30 min after recovery of normal blood pressure (T₃), and 20 min after recovery of two-lung ventilation (T₄).</p><p><b>RESULTS</b>PetCO₂and PaCO₂were well correlated during two-lung ventilation and OLV in group A (P<0.05). In group B, [(Pa-et)CO₂] at T₂was significantly higher than that in group A, but PetCO₂was still correlated with PaCO₂(P<0.05). Qs/Qt increased more obviously in group B than in group A in T₂(P<0.05). Bo obvious correlation was found between the [(Pa-et)CO₂] and Qs/Qt during OLV.</p><p><b>CONCLUSION</b>PetCO₂reflects the dynamic changes of PaCO₂under normal blood pressure during OLV. In the hypotension period, when [(Pa-et)CO₂] increases and the correlation coefficient between PetCO₂and PaCO₂lowers, PetCO₂may not accurately reflect the changes of PaCO₂and blood gas analysis is warranted.</p>

Changes of approximate entropy in rats during focal cerebral infarction / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes of EEG approximate entropy (ApEn) in rats during focal cerebral infarction.</p><p><b>METHODS</b>Twenty-four Sprague-Dawley (SD) rats were randomly divided into infarction group (n=12) with middle cerebral artery occlusion and sham-operated group (n=12). The EEG data (ApEn) was recorded in the bilateral areas (C3, C4) of the rats with focal cerebral infarction before the infarction and immediately and at 5, 15, 30, and 60 min after the infarction. The same measurement was carried out in the sham-operated group.</p><p><b>RESULTS</b>In the sham-operated group, ApEn in C3 and C4 showed no obvious differences at the time points (P>0.05), but in the infarction group, ApEn in C3 and C4 increased significantly after the infarction. ApEn in the ischemic area (C4) was significantly lower than that in the non-ischemic area (C3) (P<0.05). The bilateral ApEn decreased with the passage of time. ApEn in the ischemic area (C4) was significantly lowered at 30 min after the infarction in comparison with that before infarction (P<0.05). In the sham-operated group, ApEn showed no significant difference between C3 and C4. ApEn was comparable between the two groups before the operation.</p><p><b>CONCLUSION</b>ApEn can help monitor the occurrence of focal cerebral infarction of rats, and may be used to assess the extent of cerebral ischemia after infarction.</p>

Prophylactic effect of acupuncture on nausea and vomiting after laparoscopic operation / 中国针灸

<p><b>OBJECTIVE</b>To explore the prophylactic effect of acupuncture Neiguan (PC 6) on nausea and vomiting after laparoscopic operation.</p><p><b>METHODS</b>One hundred patients with laparoscopic gastrointestinal operation were randomly divided into an acupuncture group and a control group, 50 patients in each group. The operation was carried out with the combined infusion and inhalation anesthesia. The patients in the acupuncture group were being punctured at bilateral Neiguan (PC 6) before anesthesia and during the operation. The needles were extracted after operation, and the acupoints were covered with opaque tape. In contrast, the patients in the control group only accepted tape covering without acupuncture. After operation, all patients were given the self-controlled intravenous analgesia, and followed up at 6 h, 12 h, 24 h, 48 h for recording the incidence rate of the nausea, retching and vomiting, then scoring with VAS.</p><p><b>RESULTS</b>At 6 h, 12 h, 24 h, 48 h after operation, in the acupuncture group, the incidence rates of the nausea were 12.0%, 6.0%, 6.0% and 2.0%, and the incidence rates of the retching were 0, 0, 2.0% and 2.0%, respectively; in the control group, the incidence rates of the nausea were 28.0%, 20.0%, 12.0% and 2.0%, and the incidence rates of the retching were 2.0%, 6.0%, 2.0% and 0, respectively. At 6 h, 12 h after operation, the incidence rates of the nausea and retching in the acupuncture group were lower than those of the control group (P < 0.05, P < 0.001). The vomiting was not happened in both groups. There was no difference between the two groups according to the scoring with VAS.</p><p><b>CONCLUSION</b>Acupuncturing at Neiguan (PC 6) can reduce the incidence rates of the patients' nausea and retching after laparoscopic operation, especially in 24 h.</p>

Time window for intubation after rocuronium administration during target-controlled infusion of propofol and sulfentanil / 南方医科大学学报

<p><b>OBJECTIVE</b>To define the ideal time window for intubation after rocuronium administration during target-controlled infusion (TCI) ofpropofol and sulfentanil.</p><p><b>METHODS</b>One hundred and twenty elective surgical patients (age range 18-55 years) were randomized into 4 groups (n=30) according to the intubation time after administration of the muscle relaxant. Patients with predicted difficult airway were excluded. General anesthesia was induced by TCI of propofol and sulfentanil. A senior anesthesiologist blinded for the randomization performed the intubations at 1, 2, 3, or 4 min after injection of rocuronium, and the vocal card visibility was evaluated upon full exposure of the vocal cord and the intubation conditions assessed according to Cooper's score.</p><p><b>RESULTS</b>The intubation conditions were excellent or good in all patients, but the vocal cord visibility at 2-4 min differed significantly from that at 1 min after rocuronium administration (P<0.01). Suppression of the neuromuscular function 1 min after rocuronium administration differed significantly from that at other time points (P<0.01).</p><p><b>CONCLUSION</b>The condition of vocal cord can be more suitable for intubation at 2-4 min than at 1 min after rocuronium administration as the ideal time window for intubation during TCI of propofol and sulfentanil.</p>