title: The influence of interscalene block technique on adverse hemodynamic events.
abstract: OBJECTIVE
  A hemodynamic event such as hypertension after interscalene block (ISB) is a complication that is often overlooked. The irregular spread of local anesthetic would cause a blockade of carotid sinus baroreceptors leading to the adverse event. The purpose of the present study is to compare ultrasound and neurostimulation technique in preventing hypertension after ISB.
  
  
  METHODS
  Thirty patients without hypertension history who underwent arthroscopic shoulder surgery for a rotator cuff tear were enrolled. After preoperative administration of the State Trait Anxiety Inventory questionnaire, patients were allocated to receive ultrasound-guided ISB with 20 ml levobupivacaine-HCl 0.5 % (group US) and 40 ml levobupivacaine-HCl 0.5 % with neurostimulation (group NS). The need for antihypertensive drug was recorded. Block onset sensory and motor times were assessed. Systolic and diastolic blood pressures, and heart rate and pulse oximetry (SpO2), were evaluated before the block as well as 2, 5, 10, 15, 20, and 30 min after.
  
  
  RESULTS
  No differences in patient characteristics and anxiety were found in the two groups. Block onset times were similar. At 15 min after block placement, group NS showed significantly higher systolic and diastolic blood pressures compared to group US. No differences in heart rate and SpO2 were found between the two groups. Three patients of group NS required urapidil administration because of hypertension.
  
  
  CONCLUSIONS
  Ultrasound-guided ISB permits the use of a low volume of local anesthetic and seems to reduce the incidence of hypertension.
authors.affiliation: Section of Anesthesia and Intensive Care, Department of Critical Medical-Surgical Area, University-Hospital Careggi, Largo Brambilla, 1, 50143, Florence, Italy, gianesello.lara@libero.it.
authors.forename: Lara
authors.initials: L
authors.lastname: Gianesello
authors.forename: Manuela
authors.initials: M
authors.lastname: Magherini
authors.forename: Vittorio
authors.initials: V
authors.lastname: Pavoni
authors.forename: Andrew
authors.initials: A
authors.lastname: Horton
authors.forename: Alessandra
authors.initials: A
authors.lastname: Nella
authors.forename: Maria Consolata
authors.initials: MC
authors.lastname: Campolo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D001182:Arthroscopy / Q000379:methods; D001917:Brachial Plexus / Q000000981:diagnostic imaging; D002045:Bupivacaine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D006439:Hemodynamics; D006801:Humans; D006973:Hypertension / Q000209:etiology*; D000077554:Levobupivacaine; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects* / Q000379:methods*; D012782:Shoulder / Q000601:surgery; D014463:Ultrasonography / Q000009:adverse effects / Q000379:methods
chemical_list: D000779:Anesthetics, Local; D000077554:Levobupivacaine; D002045:Bupivacaine