title: Subtenon block combined with general anesthesia for vitreoretinal surgery improves postoperative analgesia in adult: a randomized controlled trial.
abstract: OBJECTIVE
  To evaluate the effects of subtenon block (SB) as an adjunct to general anesthesia on intraoperative oculocardiac reflex (OCR), postoperative pain, and postoperative nausea and vomiting (PONV) for vitreoretinal surgery.
  
  
  METHODS
  Prospective, randomized, double-blinded clinical trial.
  
  
  METHODS
  Operating room, postanesthesia care unit, and ward at a university-affiliated hospital.
  
  
  METHODS
  Eighty patients aged 40 to 65 years of American Society of Anesthesiologists I to II requesting general anesthesia for vitreoretinal surgery. Intervention and Measurements Patients were randomly assigned to 1 of 2 groups receiving either SB with mixture of 4 mL of 2% lidocaine and 0.5% bupivacaine (50:50) in group SB or subtenon injection of saline in group C after induction of anesthesia and before surgery in a double-blind manner. The time to first postoperative analgesic dose, incidence of intraoperative OCR, postoperative pain scores, perioperative analgesic requirements, number of patients requiring rescue analgesics during the 24-hour study period, incidence of PONV, and possible complications were recorded.
  
  
  RESULTS
  Time to first postoperative analgesia was significantly longer in group SB (P= .002). Pain scores at the first 6 hours postoperatively were significantly lower in group SB (P= .002). Intraoperative and postoperative analgesic requirements were significantly reduced in group SB (P= .015). The incidence of OCR and PONV also significantly decreased in this group (P= .001 and P= .011, respectively).
  
  
  CONCLUSIONS
  Use of SB combined with general anesthesia in patients undergoing vitreoretinal surgery reduces postoperative analgesic requirements and complications such as intraoperative OCR and PONV.
authors.affiliation: Department of Ophthalmology, King Saud University, Riyadh, Saudi Arabia. Electronic address: dr.abouammoh@gmail.com.
authors.forename: Marwan A
authors.initials: MA
authors.lastname: Abouammoh
authors.affiliation: Department of Anesthesia, Alexandria University, Egypt, Affiliated to King Saud University, Riyadh, Saudi Arabia.
authors.forename: Ashraf A
authors.initials: AA
authors.lastname: Abdelhalim
authors.affiliation: Department of Anesthesia, National Liver Institute, Menufiya University, Egypt, Affiliated to King Saud University, Riyadh, Saudi Arabia.
authors.forename: Elsyed A
authors.initials: EA
authors.lastname: Mohamed
authors.affiliation: Department of Anesthesia and Intensive Care, Al-Azhar University, Egypt, Affiliated to King Saud University, Riyadh, Saudi Arabia.
authors.forename: Ismail
authors.initials: I
authors.lastname: Elzoughari
authors.affiliation: Department of Anesthesia, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Mustafa
authors.affiliation: Department of Anesthesia, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Tariq A
authors.initials: TA
authors.lastname: Al-Zahrani
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D002045:Bupivacaine / Q000008:administration & dosage; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D010149:Postoperative Pain / Q000517:prevention & control; D020250:Postoperative Nausea and Vomiting / Q000453:epidemiology; D011446:Prospective Studies; D012024:Reflex, Oculocardiac / Q000187:drug effects; D057586:Vitreoretinal Surgery / Q000379:methods*
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine; D002045:Bupivacaine
keywords: Analgesia; Anesthesia; Block; General; Subtenon; Vitreoretinal surgery