COMPARATIVE STUDY BETWEEN POSTERIOR AND ANTERIOR ACCESSES FOR INTERSCALENE BRACHIAL PLEXUS BLOCK IN SHOULDER ARTHROSCOPY

Background: Regional anaesthesia has enjoyed a tremendous increase in popularity over the past two decades. With modern general anaesthetic techniques, recoveringafter surgery can be both rapid and complete. However, in many day care patients, regional anaesthetic techniques might be preferable. Regional anaesthesia can reduceor avoid the hazards and discomforts of general anaesthesia including sore throat, airway trauma, and muscle pain, and it also offers a number of advantages to outpatients undergoing surgery. These techniques provide analgesia without sedation, earlier discharge, and prolonged post operative analgesia. Regional anaesthesia reduces the requirements of opioids therefore reducing the incidence of postoperative nausea and vomiting. It can be used alone, or in combination with sedation techniques or part of balanced analgesia with general anaesthesias. One of the types of regional anaesthesia is the brachial plexus blocks which are frequently used for patients needing upper extremity surgery, Now its role has expanded from the operating suite into arena of post operative and chronic pain management. With appropriate selection and sedation, these techniques can be used in all age groups. Skillful application of peripheral neural blockade broadens the anaesthesiologist s range of options in providing optimal anaesthetic care. Interscalene brachial plexus block (ISB) is ideal for the proximal upper limb surgery but less reliable for neural blockade of the wrist and the hand. Materials and Methods: The present work is aprospective and single blind study. It includes 40 patients of ASA physical status I, II and III, of both sexes and age range between 18-60 years. They were scheduled for shoulder arthroscopy. Informed written consents were taken from all patients after approval of Ain Shams University Ethics Committee. 40 patients were randomly allocated into one of two groups according to the approach of ISB. Group A are 20 patients received anterior access with 30 ml of ropivacaine 0.75% and Group P are 20 patients received posterior access with 30 ml of ropivacaine 0.75%. Results: The degree of motor blockade of axillary nerve was more in the anterior group than the posterior group. The degree of the sensory block was more in the posterior group in the cutaneous distribution of cervical roots. No differences regarding patient s satisfaction between the two studied groups. Five patients (25%) experienced pain during needle entry in the posterior group in comparison to two patients (10%) in the anterior one. Two patients (10%) showed blood during puncture in the anterior group compared to only one patient (5%) in the posterior group. Bilateral spread occurred in one patient (5%) in the posterior group. Conclusion: the posterior access is superior in sensory blockade than the anterior access. As regards the motor blockade, the anterior access is superior in the motor blockade than the posterior access. As regards the complications, the pain at needle entry was more in the posterior access, and the incidence of hematoma is higher in the anterior access group.