The Time Of Local Anesthetic Fading And Its Influencing Factors After Transversal Plane Block Were Monitored By Ultrasound

Objective: In this project,the time required for local anesthesia to be absorbed into the transversal fascia and the duration of the blocking and analgesic effect in Transversus Abdominis Plane Block TAPB under ultrasound guidance were observed,and the influencing factors of both were analyzed.Methods:This observational,prospective clinical study enrolled 150 patients undergoing gastrointestinal surgery(ASAII-III).All patients received postoperative TAPB block by bilateral oblique subcostal approach guided by ultrasound,with 20 m L0.375% ropivacaine injected into each side.After local anesthetic was injected,the puncture point was marked,and the drug diffusion site was examined by ultrasound every half an hour until the local anesthetic was completely absorbed,and the time was recorded.At the same time,cold stimulation was used to test the nerve blocking effect.The main data collected were the time required for 0.375% ropivacaine 20 ml to be completely absorbed in the transverse abdominal muscle plane space under ultrasonic monitoring.The secondary data collected was the duration of the blocking effect as judged by the cold stimulation method.In this experiment,one-way analysis of variance and multi-factor analysis of variance were used to analyze the influencing factors.Results: The mean absorption time of 150 subjects was 11.9 hours and the median was11.5 hours.The fastest absorption time was 8.5 hours,and the slowest absorption time was 15.5 hours.The 150 subjects had a mean duration of 8.4 hours and a median duration of 8.5 hours.The shortest action time was 5 hours and the longest action time was 13 hours.Absorption duration and duration of action were taken as dependent variables,operation mode,BMI index,gender,age,whether there was hypertension,diabetes and coronary heart disease were taken as independent variables for univariate analysis of variance,and then positive results were taken as independent variables for multivariate analysis of variance.Conclusion: The absorption time of bilateral oblique rib subcostal TAP block under ultrasound varies from 8 to 15 hours,and the extensive cutaneous sensory block caused by local anesthetics can act for about 6 to 12 hours.Age and BMI have an effect on the absorption time of drugs and age has an effect on the action time of block.