ABSTRACT
Objective To investigate the effects of different volumes of ropivacaine with the same solubility in supraclavicular brachial plexus block(SCBPB) under ultrasound guidance on ipsilateral diaphragmaticparalysis.Methods Seventy two patients (32 males,40 females, aged 18-65 years, of ASA Ⅰ or Ⅱ, scheduled for the right upper limb fracture internal fixation removal were randomized into group A (0.375% ropivacaine 20 ml) and group B (0.375% ropivacaine 30 ml), 36 cases in each group.The onset and duration of sensory and motor block were observed as well as complication.Diaphragmatic excursion were evaluated by M type ultrasound before and 30 min after drug injection under eupnea and forced respiration through observing diaphragmatic excursion to study diaphragmatic paralysis.Results The onset time of sensory block and maintaining time of sensory block or motor block had no significant difference between the two groups.Compared with group A,the onset time of motor block in group B was significantly shorter (P<0.05).Twelve cases (33.3%) in group A and 22 cases (61.1%) in group B respectively showed complete or partial hemidiaphragmatic paralysis 30 min after drug injection.Compared with group A, the rate of diaphragmatic paralysis in group B was significantly higher (P<0.05).Conclusion Supraclavicular brachial plexus block under ultrasound guidance with 0.375% ropivacaine 20 ml or 30 ml both can provide excellent anesthetic effect.0.375% ropivacaine 20 ml is less likely to lead to diaphragmatic paralysis.
ABSTRACT
Objective To investigate the influence of ropivacaine with isodosage on heart rate variability (HRV ) following interscalene brachial plexus block under ultrasound guidance. Methods Forty-five ASA grade Ⅰ patients (28 males,1 7 females,aged 18-50 years)scheduled for upper limb fracture internal fixation removal were randomized into group R1 (0.375% ropivacaine 40ml),group R2(0.5% ropivacaine 30ml)and group R3 (0.75% ropivacaine 20 ml),1 5 in each group.Changes in HRV,such as LF,HF,LF/HF,SDNN,RMSSD,PNN50% were evaluated with dynamic electrocardiogram.The degree and duration of sensory and motor block were recorded 30 min after drug injection.Results The anesthetic effect and maintaining time had no significant difference among the groups.The incidence rate of Horner syndrome had no significant difference among groups,group R1 was 26.7%,group R2 20% and group R3 20%.LF(30 min after drug injection)in both group R2 and group R3 were significantly decreased compared with that before drug injection, and the decreased degree of LF had significant difference among the three groups.SDNN(30 min after drug injection)in group R2 and PNN50% in group R3 were significantly decreased compared with that before drug injection.The time required for LF,the most obvious changeable HRV parameter, returning to the pre injection level was (876.2 +43.7)min for group R1,(798.8 + 61.5 )min for group R2, group R3 (712.2 + 45.7 ) min, the difference between the three groups was not statistically significant.Conclusion ISBPB can affect the stability of the cardiovascular autonomic ac-tivities by reducing the cardiac sympathetic nerve function and increasing parasympathetic nerve func-tion,possibly through blockade of stellate ganglion or branches of vagus nerve.Along with the in-crease of the dose of anesthetic,the influence on HRV is greater.
ABSTRACT
Objective To evaluate mivacurium-induced release of histamine in the patients undergoing general anesthesia.Methods Eighty patients of both sexes,aged 19-58 yr,weighing 42-75 kg,of ASA physical status Ⅰ or Ⅱ,undergoing ureteroscopy under general anesthesia,were randomly divided into 2 groups (n =40 each) using a random number table:rocuronium group (group R) and mivacurium group (group M).Anesthesia was induced with iv midazolam 0.04 mg/kg,fentanyl 3 μg/kg,etomidate 0.3 mg/kg,and mivacurium 0.20 mg/kg (group M) or rocuronium 0.75 mg/kg (group R).Streamlined liner of the pharynx airway (SLIPA) was inserted for mechanical ventilation.PET CO2 was maintained at 35-40 mmHg.Anesthesia was maintained with fentanyl and propofol.Before muscle relaxant administration,at 3 min after muscle relaxant administration and at 5 min after insertion of SLIPA,venous blood samples were collected for determination of plasma histamine concentrations (by HPLC) and the histamine release was classified.Results Compared with group R,the plasma histamine concentration and histamine release were increased at 3 min after muscle relaxant administration in group M.No fatal responses caused by histamine release were found in the two groups.Conclusion Although mivacurium induces release of histamine,it can still be safely used for the patients undergoing ureteroscopy under general anesthesia.