title: Effect of noise block using earplugs on propofol sedation requirement during extracorporeal shock wave lithotripsy.
abstract: OBJECTIVE
  To determine effect of noise block using earplugs on reducing propofol infusion needed to maintain a constant bispectral index (BIS) values in patients undergoing extracorporeal shock wave lithotripsy (ESWL).
  
  
  METHODS
  Fifty-eight patients (18-65 years) with nephrolithiasis undergoing ESWL, having ASA physical status I or II and have normal hearing function tested by audiometry were enrolled in this randomized, double-blind, controlled trial. Patients were randomized and allocated into two groups: noise blocked group (earplugs inserted into both ears) and control group (earplugs not inserted). Sedation by target-controlled infusion was started with 1.2 mcg/mL of propofol and propofol target concentration was adjusted gradually by 0.2 mcg/ml every 5 minutes intraoperatively to achieve and maintain bispectral index (BIS) values within 75-80% until the procedure finished. Total amount of propofol (mg), BIS values (%), ambient noise level (dB) and patient satisfaction (1-5) were measured.
  
  
  RESULTS
  The amount of propofol infusion needed to maintain a constant BIS index value in patients undergoing ESWL in the noise blocked group was significantly lower than that in the control group (6.91 +/- 2.05 vs. 8.23 +/- 2.16 mg/kg/m2/hr, p = 0.021). Patient satisfaction was similar in both groups (4 [1] vs. 4 [1], p = 0.929).
  
  
  CONCLUSIONS
  Noise diminution in ambient operating room can reduce the amount of propofol needed to maintain light sedation during ESWL.
authors: Department of Anesthesiology, Rajavithi Hospital, College of Medicine, Rangsit University, Bangkok, Thailand. supabura@windowslive.com
authors: Supaporn
authors: S
authors: Tharahirunchot
authors: Suwanna
authors: S
authors: Tatiyapongpinij
authors: Ketchada
authors: K
authors: Uerpairojkit
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016292:Procedural Sedation / Q000379:methods*; D056805:Consciousness Monitors; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004569:Electroencephalography / Q000187:drug effects; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage*; D007262:Infusions, Intravenous; D008096:Lithotripsy; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D009622:Noise / Q000009:adverse effects*; D009873:Operating Rooms; D017060:Patient Satisfaction; D015742:Propofol / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D006993:Hypnotics and Sedatives; D015742:Propofol