ABSTRACT
Objective To determine the optimum cuff pressure of the flexible laryngeal mask airway (LMA) for airway management in pediatric patients.Methods One hundred and twenty pediatric patients undergoing strabismus surgery with general anesthesia,of American Society of Anesthesiologists physical status Ⅰ or Ⅰ,aged 3-10 yr,were randomly divided into 3 groups (n=40 each) according to the cuff pressure of the flexible LMA:20 cmH2O pressure group (group A),40 cmH2O pressure group (group B) and 60 cmH2O pressure group (group C).The cuff was inflated to the predetermined pressure using the inflatable cuff manometer in each group.Oropharyngeal leak pressure was measured after LMA placement.Peak airway pressure and the difference between inhaled and exhaled tidal volume were recorded at 5 min of positive pressure ventilation.The LMA insertion condition,LMA removal time,and development of sore throat,hoarseness,dysphagia and abdominal distention within 24 h after operation were recorded.Results There were no significant differences in the success rate of LMA placement at first attempt,peak airway pressure,or incidence of sore throat among the three groups (P＞0.05),and no hoarseness or dysphagia was found in the three groups.Compared with group A,oropharyngeal leak pressure was significantly increased,and the difference between inhaled and exhaled tidal volume and incidence of abdominal distention were decreased in B and C groups (P＜0.05).There was no significant difference in the parameters mentioned above between group B and group C (P＞0.05).Conclusion The optimum cuff pressure of the flexible LMA is 40 cmH2O when used for airway management in the pediatric patients.
ABSTRACT
Objective To evaluate the effects of postconditioning with ischema and propofol on retinal injury induced by limb ischemia-reperfusion (LIR) in rats.Methods Twenty-four male Wistar rats were randomly divided into 3 groups (n =8 each) using a random number table:sham operation group (group S),group LIR,and propofol postconditioning + postconditioning + ischemic LIR group (group P + I + LIR).The model of LIR was established by separating and ligating the femoral artery and vein of bilateral hind limbs for 60 min followed by reperfusion.In group P + I + LIR,the animals were subjected to 4 episodes of 60 min ischemia-5 min reperfusion-5 min ischemia-5 min reperfusion and to 4 cycles of propofol 500 μg· kg-1 · min-1 infused intraperitoneally at the same time (during reperfusion)-no propofol infusion during second ischemia.At 120 min of reperfusion,blood samples were collected from the abdominal aorta for determination of serum malondialdehyde (MDA) concentrations.The eyeball was removed and the retina was cut into sections which were stained with H.E.and examined by microscopy.Results Compared with group S,the serum MDA concentration was significantly increased in group LIR,and no significant change was found in the serum MDA concentration in group P + I + LIR.The serum MDA concentration was significantly lower in group P + I + LIR than in group LIR.The structure of retina was normal in group S,oedema was found in all the layers of retina,vacuolar degeneration was observed in the most of ganglionic layers,and the structure disturbance was found in group LIR.The pathological changes of retina were significantly attenuated in group P + Ⅰ + LIR.Conclusion Postconditioning with ischema and propofol can attenuate retinal injury induced by LIR,and the mechanism is related to inhibition of lipid peroxidation in rats.
ABSTRACT
Objective To investigate the effects of different infusion rates of remifentanil infusion on spontaneous ventilation in children received sevoflurane anesthesia. Methods A total of 120 children underwent strabismus surgery were randomly assigned to four groups: C group (administration of saline), L group (remifentanil 0.03 μg · kg-1 · min-1), M group (remifentanil 0.06μg · kg-1 · min-1) and H group (remifentanil 0.09μg · kg-1 · min-1). The mean blood pressure (MBP), heart rate (HR), respiratory rate (RR), tidal volume (VT), minute ventilation (MV), endtidal CO2 [p(CO2)] and endtidal SEV were recorded after laryngeal mask insertion (T1), an initial bolus dose of remifentanil (T2),10 mins after remifentanil infu-sion (T3),15 mins after remifentanil infusion (T4) and laryngeal mask remove (T5) respectively. The adverse events and time of induction, maintenance and emergence were also recoded. Results There were no significant differences in patient age, body mass index, anesthesia time, operation time, HR and MBP at different time points between four groups. No body movement and hypoxemia were observed. The values of RR and MV at T3, T4 and T5 were significantly lower in H group than those of other three groups (P <0.05). Values of p(CO2)at T3 and T4 were significantly higher in H group than those of other three groups (P<0.05). The values of RR at T3, T4 and T5 were significantly lower in L group and M group than those of C group. The values of MV at T3 and T4 were significantly lower in L group and M group than those of C group. p(CO2)at T4 was significantly higher in L group and M group than that of C group(P<0.05), but no significant difference was found be-tween L group and M group. There was no significant difference in value of VT between four groups. Conclusion Remifent-anil infusion at a rate of 0.03~0.09μg·kg-1·min-1 could depress spontaneous ventilation in children received sevoflurane an-esthesia. The respiratory depression effect is mainly manifested by reduction of RR. It is a good option to choose 0.03~0.06μg · kg-1 · min-1 infusion to keep spontaneous ventilation and avoid severe respiratory depression according to the demand of operations in children.
ABSTRACT
Objective To observe the sedative and analgesic effects of local anesthesia with midazolam and sufent-anil for patients in ophthalmologic plastic surgery. Methods A total of 160 patients (ASA I-II) were randomly divided into two group using a random number table, 80 cases in each group, groupⅠ: local anesthesia and groupⅡ: local anesthesia with midazolam (0.05 mg/kg) and sufentanil (0.1μg/kg). Values of bispectral index (BIS), systolic blood pressure (SBP), dia-stolic blood pressure (DBP), heart rate (HR), respiratory rate (RR), oxyhemoglobin saturation(SpO2) and visual analogue scale (VAS) were recorded after patients entered into the operating room, during the time of injection of local anesthesia, at the beginning of the procedure, 20 min after the surgery and after operation. It was also recorded including hypoxemia, ap-noea, restlessness, nausea and vomiting and the duration of surgery. Results There were no significant differences in age, gender, weight and duration of surgery between two groups of patients. There was a significantly lower BIS value before inject-ing local anesthesia, at the beginning of the surgery and 20 min after the surgery compared with that of time point that pa-tients entered into the operating room in groupⅡ(P<0.05). In groupⅠthere were significantly higher values of SBP, DBP and HR during the injection of local anesthesia, at the beginning of the procedure, 20 min after the beginning of the proce-dure and after the surgery than those of time point that patients entered into the operating room;the value of RR was signifi-cantly increased during the injection of local anesthesia, at the beginning of the procedure and 20 min after the beginning of the procedure than that of time point that patients entered into the operating room (P<0.05). Compared with before anesthe-sia induction, values of SBP, DBP, HR and RR were significantly decreased in groupⅡ(P<0.05). There were significantly lower levels of SBP, DBP, HR and RR during the local anesthesia injection to the time after surgery in groupⅡthan those of groupⅠ. The value of VAS was significantly higher during the time of injection of local anesthesia and during the surgery in groupⅠthan that of groupⅡ(P<0.05). There were 15 patients with restlessness in group I, which were higher than those of groupⅡ(3 patients with restlessness). There were 3 patients with nausea and 3 patients with anoxemia and no apnea in group Ⅱ. Conclusion The conscious sedation with midazolam and sufentanil is an effective anesthetic technique for patients in ophthalmo-logic plastic surgery.