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Objective To compare the efficacy of supraclavicular approach and infraclavicular approach in ultrasound-guided brachial plexus block(BPB).Methods One hundred and twenty patients,ASA Ⅰ-Ⅲ,aged 18-80 yr,scheduled for upper extremity surgeries of both gender,were randomized into two groups(n =60):supraclavicular group(group SCB)and infraclavicular group(group ICB).The anesthetic mixture consisted of ropivacaine 0.375％ and lidocaine 1％ in equal volumes with epinephrine 1∶200 000,the total dose was 0.5 ml/kg.The block performance time,duration of anesthesia and success of anesthesia(surgery was accomplished without supplementary block)were recorded.A blinded observer assessed pinprick sensory block in the seven distal nerve territories(axillary,radial,musculocutaneous,median,ulnar,medial antebrachial and medial brachial cutaneous nerves)every 5 min up to 30 min after injection.Success of nerve block,side effects and complications were recorded during and after operalion.Results Group ICB was superior in success rate of anesthesia and nerve block of ulnar,medial antebrachial and medial brachial cutaneous nerves,the rate of parasthesia was lower and the block performance time was longer compared with group SCB(P ＜ 0.05).No major complications occurred in both groups.Conclusion Under ultrasound guidance,infraclavicular BPB is superior to supraclavicular approach.
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Objective To investigate the effect of propofol pretreatment on hypoxia-induced apoptosis of alveolar epithelial type Ⅱ (AE Ⅱ) cells in fetal rats. Methods Primary cultured AE Ⅱ cells isolated from fetal rats were seeded in 96-well plates (1 × 106/L, 180 μl/well) and randomly assigned to one of 3 groups (n = 72each):normal control group (group C), hypoxia group (group H) and propofol-hypoxia group (group P-H).Group H and P-H were exposed to hypoxia (5% O2). In group P-H, propofol (final concentration 5 μ mol/L) was added 1 h prior to hypoxia (5% O2). The apoptotic rate and expression of hypoxia-inducible factor (HIF)-1αmRNA, Bnip3L mRNA, HIF-1α protein and Bnip3L protein were determined at 3, 12, 24 and 48 h of hypoxia.Results The apoptotic rate and expression of HIF-1α mRNA, Bnip3L mRNA, HIF-lα protein and Bnip3L protein were significantly up-regulated in group H compared with group C (P ＜ 0.05). Propofol pretreatment could significantly inhibit the hypoxia-induced changes mentioned above (P ＜ 0.05). Conclusion Propofol pretreatment can inhibit hypoxia-induced apoptosis of AE Ⅱ cells, and the mechanism is related to inhibition of HIF-1αactivation and down-regulation of Bnip3L expression in fetal rats.
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Objective To evaluate the changes in peripheral?1-adrenergic receptor sensitivity in a rat model of chronic high spinal cord injury (SCI)Methods Thirty male 18-week-old Wistar rats weighing 290-310g were randomly divided into 2 groups: SCI group (n=24) and control group (C n=6) . The animals were anesthetized with intraperitoneal 2 % pentobartital 50 mg?kg-1 and subjected to spinal cord injury (SCI) at T4 according to modified Allen's method. Successful high SCI was confirmed by bilateral hindlimb flaccid paralysis. Three weeks after SCI the animals were further divided into 4 subgroups (n=6) receiving 4 different doses of phenylephrine 1, 2, 3 and 4 ?g?kg-1 i.v. Femoral artery was connulated for BP (SBP and DBP) and HR monitoring. HR and SBP and DBP were recorded before and after i.v. phenylephrine injection. In control group phenylephrine (PE) 1,2,3 and 4 ?g?kg-1 were injected i.v. successively at an 1h interval. % changes in HR, SBP and DBP were calculated: % change = (post-injection value- baseline value) / baseline value. Results The animals lost weight and HR was significantly slower and SBP and DBP were significantly lower 3 weeks after SCI as compared with control group. In both group C and SCI, HR was significantly decreased and SBP and DBP were significantly increased after i.v. PE injection as compared to the baseline value before PE. The % changes in HR, SBP and DBP were significantly greater in group SCI than in group C. Conclusion In a rat model of chronic high SCI, peripheral?1-adrenergic receptor sensitivity is significantly increased 3 weeks after high SCI.
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Objective:To assess the effects of different fluid therapies on myocardial function,blood-spinal cord barrier and water content of spinal cord after acute high level spinal cord injury(SCI) in rats.Methods: Thirty-two male SD rats, weighing (300?20) g, were anesthetized intraperitoneally with pentobarbital (40 mg/kg). A cervical laminectomy extending from C6-T1 was performed and the experimental acute cervical 7 spinal cord injury model was created by modified Allen’s method,and then the rats were randomly divided into 4 groups(n=8): control group(C group) with no fluid resuscitation, 7.5% hypertonic saline group(HS group), 6% hydroxyethyl starch group(HES group) and banlanced solution group (BS group).Fifteen minutes after injury, rats of each treatment groups were given (iv. at 4 ml/kg) above-mentioned fluids in 4 min,then continuously infused at a rate of 10 ml?kg -1 ?h -1 over for 30 min.MAP,HR,left ventricular systolic pressure (LVSP),and ?dp/dt max were recorded at 5,15 and 30 min.At 30 min, 0.5% Evan's blue(EB) 1 ml was injected iv.Two hours later the animals were sacrificed and the injured segments of spinal cords were removed for determination of water content and EB content.Results:After SCI there were no differences of HR at different time points in each group. At 5 min,HS significantly increased MAP,LVSP and ?dp/dt max compared with control group(P
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Objective:To observe the changes of ? 1 -adrenergic receptors expression in a high-level spinal cord injury (SCI) rat model,providing information for studying the mechanisms of severe hypertension of autonomic dysreflexia.Methods: Adult male Wistar rats were divided into 2 groups: sham-lesion group(n=6) and SCI group(n=36). Severe spinal crush injury was induced at T 4 using modified Allens device in SCI group, while sham-lesion group received laminectomy at T 4 only.The expression of ? 1 -adrenergic receptors mRNA in different segments of spinal cord:injured segment(I), above(A) and below(B) the injured site, were measured by reverse-transcription polymerase chain reaction (RT-PCR) 1 d, 3 d, 7 d, 2 weeks, 3 weeks and 4 weeks after SCI. Results: Compared with sham-lesion group,the express of ? 1 -adrenergic receptors mRNA in group A decreased 3 d after SCI and dropped to the least 1 week later,and restored to the normal level 2 weeks later.The impairment of ? 1 -adrenergic receptors mRNA expression in group I occured immediately after SCI and hit the lowest value 3 d later,and did not recover to the nomal 4 weeks later.Decrease of ? 1 -adrenergic receptors mRNA expression in group B were detected 1 d after SCI,but began to increase on 3 d and exceeded that of group C 4 weeks later.Conclusion: In chronic SCI rat models ? 1 -adrenergic receptors expression increases below the level of SCI,which might be a contributing factor to the severe hypertension of autonomic dysreflexia.