title: Propofol and alfentanil for sedation during placement of retrobulbar block for cataract surgery.
abstract: OBJECTIVE
  To determine if the addition of alfentanil to propofol is more effective than propofol alone to provide adequate conditions for placement of a retrobulbar block prior to cataract surgery.
  
  
  METHODS
  Randomized, double-blinded study.
  
  
  METHODS
  Outpatients at a university hospital.
  
  
  METHODS
  40 adult ASA physical status I, II, and III outpatients scheduled for elective cataract surgery.
  
  
  METHODS
  Patients were randomly assigned to receive one of four drug combinations prior to the placement of a retrobulbar block: Group 1, propofol alone; Group 2, alfentanil 5 micrograms/kg plus propofol; Group 3, alfentanil 10 micrograms/kg plus propofol; Group 4, alfentanil 15 micrograms/kg plus propofol. All patients were preoxygenated by face mask for two minutes prior to drug administration. The quality of conditions for block placement were determined by: (1) assessing the amount of movement by the patients while the block needle was in place, (2) cooperativeness of the patients during the operation, (3) hemodynamic side effects, (4) incidence and severity of respiratory depression, (5) incidence of nausea and vomiting, (6) recall of placement of the block, and (7) time to discharge from the hospital.
  
  
  RESULTS
  The addition of alfentanil to propofol for sedation prior to placement of the retrobulbar block resulted in a dose-dependent reduction in movement by the patients. However, the highest dose of alfentanil (15 micrograms/kg) resulted in the greatest frequency (40% of the patients in this group) of respiratory depression (SpO2 < 90%). All patients were cooperative during the operation and responsive to verbal command within 5 minutes of placement of the block. In addition, all of the patients denied being nauseated, having vomited, or recalling block placement in the recovery room or the next day.
  
  
  CONCLUSIONS
  The combination of alfentanil and propofol may be used to sedate patients in order to limit movement and provide a cooperative, alert patient with stable hemodynamics and limited respiratory depression during placement of retrobulbar block prior to ophthalmic surgery. However, excessive dosage of these drugs may result in hazardous respiratory depression in this patient population.
authors.affiliation: Department of Anesthesiology, University of Utah School of Medicine, Salt Lake City, USA.
authors.forename: J B
authors.initials: JB
authors.lastname: Yee
authors.forename: T A
authors.initials: TA
authors.lastname: Burns
authors.forename: J M
authors.initials: JM
authors.lastname: Mann
authors.forename: A S
authors.initials: AS
authors.lastname: Crandall
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015760:Alfentanil / Q000008:administration & dosage*; D000556:Ambulatory Surgical Procedures; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D002387:Cataract Extraction; D016292:Procedural Sedation; D003299:Cooperative Behavior; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D017558:Elective Surgical Procedures; D005123:Eye; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage*; D015994:Incidence; D007902:Length of Stay; D008297:Male; D011939:Mental Recall / Q000187:drug effects; D008875:Middle Aged; D009068:Movement; D009325:Nausea / Q000139:chemically induced; D009339:Needles; D009407:Nerve Block / Q000295:instrumentation; D015742:Propofol / Q000008:administration & dosage*; D012119:Respiration / Q000187:drug effects; D014839:Vomiting / Q000139:chemically induced
chemical_list: D018686:Anesthetics, Intravenous; D006993:Hypnotics and Sedatives; D015760:Alfentanil; D015742:Propofol