Interscalene block for postoperative analgesia using only ultrasound guidance: the outcome in 200 patients

Study ObjectiveTo report the results of single and continuous interscalene blocks (ISB) performed using ultrasound (US) guidance only.DesignProspective, observational study.SettingOperating room of a university-affiliated orthopaedic hospital.Patients200 ASA physical status I, II, and III patients undergoing shoulder or elbow surgery.InterventionsSingle or continuous ISB were placed using US guidance only. All blocks were performed by anesthesiology residents and supervised by faculty anesthesiologists.MeasurementsSuccess rate and frequency of untoward events such as needle paresthesia, vessel puncture, infection, and persistent neurologic deficits were prospectively recorded.Main Results99% of patients reported sensory and motor changes in the distribution of the brachial plexus and postoperative pain scores ≤ 2. The rates of needle paresthesia and vessel puncture were 6% and 1%, respectively. Two patients (1%) reported transient neurologic deficits. No signs or symptoms of infection or intravascular injection were noted. There were also no permanent neurologic deficits.ConclusionsIn this group of 200 consecutive patients, the success rate for postoperative analgesia using US guidance only was 99%. Untoward events such as needle paresthesia and persistent neurologic deficits were lower than existing data on nerve stimulation and paresthesia techniques. Ultrasound can be successfully used as a “stand alone” method to perform ISB.