title: Association between bispectral index and age and use of sedative drugs in high spinal anaesthesia.
abstract: OBJECTIVE
  A prospective, randomized, double-blind study using bispectral index values to objectively quantify the sedative effect of high spinal anaesthesia in patients stratified according to age, and to determine whether sedative drugs are associated with additional adverse respiratory and haemodynamic effects in older patients.
  
  
  METHODS
  Patients who were electively scheduled for lower limb or abdominal surgery were recruited and allocated into one of three groups according to their age and whether midazolam and fentanyl were used: younger (20-40 years); and older (61-80 years) with or without midazolam and fentanyl intravenous infusion.
  
  
  RESULTS
  The study recruited a total of 90 patients (n = 30 per group). Intraoperative bispectral index values were significantly lower than preoperative values in all groups. Patients in the older age group had significantly lower intraoperative bispectral index values than younger patients. Older patients were significantly more likely to experience respiratory depression (arterial oxyhaemoglobin saturation <90%) than younger patients.
  
  
  CONCLUSIONS
  The sedative effect of high spinal anaesthesia is greater in older patients than in younger patients, with an increase in respiratory instability.
authors.affiliation: Department of Anaesthesia and Pain Medicine, Institute of Medical Sciences, Kangwon National University Hospital, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Yi
authors.forename: Daeyoung
authors.initials: D
authors.lastname: Heo
authors.forename: Hee-Jeong
authors.initials: HJ
authors.lastname: Son
authors.forename: Young
authors.initials: Y
authors.lastname: Joo
authors.forename: Sang-Jin
authors.initials: SJ
authors.lastname: Lee
authors.forename: Byeongmun
authors.initials: B
authors.lastname: Hwang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000775:Anesthesia, Spinal; D056805:Consciousness Monitors; D003710:Demography; D017558:Elective Surgical Procedures / Q000009:adverse effects; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology; D055815:Young Adult
chemical_list: D006993:Hypnotics and Sedatives
keywords: Age; bispectral index; fentanyl; midazolam; sedation; spinal anaesthesia