RESUMO
Objective To evaluate the effect of postoperative patient controlled epidural analgesia (PCEA) on respiratory function in patients aged over 65 years Methods 41 ASA Ⅰ Ⅱ patients (male 22,female 19)aged between 65 80 years, weighing 58 78kg, scheduled for upper abdominal surgery were divided randomly into two groups: control group(n=20)and PCEA group(n=21) Epidural block was performed at T 8 9 with an epidural catheter inserted cranially for 4 cm A test dose of 1 5% lidocaine 4 5ml was given via epidural catheter When epidural blockade was confirmed, general anesthesia was induced with diazepam 0 2mg?kg -1 ,etomidate 0 3 mg?kg -1 ,fentanyl 4?g?kg -1 and vecuronium 0 1mg?kg -1 ,and maintained with epidural 0 5% bupivacaine infusion (6 7ml/2h) combined with inhalation of low concentration of isoflurane and intermittent iv boluses of fentanyl and vecuronium For postoperative analgesia in control group intramuscular pethidine was given on demand; In PCEA group PCEA was used A loading dose of 3ml of 0 15% bupivacaine mixture (morphine 10mg and haloperidol 5mg/0 15% bupivacaine 100ml) followed by continuous infusion of 0 5 1ml/h Superimposed by boluses of 2ml with a lock out time of 25min The maximal amount of bupivacaine mixture was 8ml/h VAS, Bruggman′s comfort scale and Rawsay′s sedation score were evaluated BP, HR, respiratory rate (RR) and SpO 2 were measured and recorded every 30min 4 h after operation Vital volume, Forced vital capacity, forced expiratory volume (first second:FEV 1 0 ),PEEP, MMEF were measured before operation and on 1st,3rd,5th and 7th postoperative days Blood gas analysis was checked before operation, during operation (30min and 90min after induction of anesthesia) and the 1st,3rd, 5th and 7th postoperative days Results The total amount of narcotic in 72h was 11 36mg (morphine equivalent dose) in control group and 5 4mg in PCEA group VAS was higher in control group than PCEA group The postoperative respiratory function was significantly better in PECA group Conclusions In elderly patient after upper abdominal operation PECA can greatly improve the respiratory function with better analgesia
RESUMO
Objective To investigate the preventive effect of midazolam pretreatment against neurotoxicity of ropivacaine and the underlying mechanism. Methods Thirty male SD rats aged 4-6 months weighing 250-300 g were randomly divided into 3 groups with 10 animals in each group: group Ⅰ blank control; group Ⅱ ropivacaine (R) and group Ⅲ midazolam-ropivacaine (M-R). In group R and M-R 0.75% ropivacaine was infused i.v. at a rate of 0.5 ml?min-1 until the animal developed convulsion. The animals were killed and brains were immediately removed for detennination of glutamate, aspartate, glycine and GABA content in the brain. Venous blood samples were taken for determination of pH and plasma concentration of lactate. The total amount of ropivacaine infused was calculated.Results The plasma lactate concentration was significantly higher and pH was significantly lower in group R than in blank control group. The concentrations of the 4 amino acids in the brain were significantly increased in group R and M-R as compared with the blank control group. The aspartate, glycine and GABA contents in the brain were significantly lower in M-R group than in R group. The total amount of ropivacaine infused i.v. was significant larger in group M-R than in group R.Conclusion Midazolam pretreatment can prevent the neurotoxicity of ropivacaine by modulating the balance between excitatory and inhibitory amino acids.