title: Localization of local anesthetic solution by magnetic resonance imaging.
abstract: OBJECTIVE
  The aim of this study was to examine the distribution of local anesthetic solution by magnetic resonance imaging (MRI) after combined peribulbar and retrobulbar, superomedial retrobulbar, and sub-Tenon's injection in relation to clinical akinesia.
  
  
  METHODS
  Randomized clinical trial.
  
  
  METHODS
  Fifteen patients scheduled for cataract surgery, 5 patients in each group.
  
  
  METHODS
  Five patients received combined peribulbar and retrobulbar anesthesia, 5 patients received superomedial retrobulbar injection, and 5 patients had sub-Tenon's injection, all with a combination of bupivacaine 0.75%, lidocaine 2%, and hyaluronidase. The MRI scans were performed before the injection and up to 35 minutes after the injection.
  
  
  CONCLUSIONS
  Reliable anesthesia is achieved using a combined peribulbar and retrobulbar block and a relatively great volume of local anesthetic solution, which spreads throughout the orbit, as evidenced by MRI. After superomedial retrobulbar and sub-Tenon's injection, the local anesthetic solution accumulates behind the globe. Sub-Tenon's injection gives good analgesia and slight akinesia with a very small volume. Superomedial retrobulbar injection and combined peribulbar and retrobulbar block provide a similar degree of exophthalmos, which seems to be the result of the volume injected behind the globe.
authors.affiliation: Department of Anesthesiology, Eye and ENT Hospital, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Leila
authors.initials: L
authors.lastname: Niemi-Murola
authors.forename: Kari
authors.initials: K
authors.lastname: Krootila
authors.forename: Riku
authors.initials: R
authors.lastname: Kivisaari
authors.forename: Aki
authors.initials: A
authors.lastname: Kangasmäki
authors.forename: Leena
authors.initials: L
authors.lastname: Kivisaari
authors.forename: Eeva-Liisa
authors.initials: EL
authors.lastname: Maunuksela
mesh_terms: D000368:Aged; D000772:Anesthesia, Local / Q000379:methods*; D019162:Anesthetics, Combined / Q000378:metabolism*; D000779:Anesthetics, Local / Q000378:metabolism*; D002045:Bupivacaine / Q000378:metabolism; D002387:Cataract Extraction; D003238:Connective Tissue / Q000378:metabolism; D005260:Female; D006801:Humans; D006821:Hyaluronoglucosaminidase / Q000378:metabolism; D008012:Lidocaine / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009407:Nerve Block; D009883:Ophthalmic Solutions / Q000378:metabolism; D009915:Orbit / Q000378:metabolism*
chemical_list: D019162:Anesthetics, Combined; D000779:Anesthetics, Local; D009883:Ophthalmic Solutions; D008012:Lidocaine; D006821:Hyaluronoglucosaminidase; D002045:Bupivacaine