title: Effect of cisatracurium versus atracurium on intraocular pressure in patients undergoing tracheal intubation for general anesthesia.
abstract: BACKGROUND
  Increase in intraocular pressure (IOP) following tracheal intubation during general anesthesia can be troublesome. We compared the influence of two muscle relaxants, cisatracurium and atracurium, on IOP in patients undergoing general anesthesia.
  
  
  METHODS
  This randomized, double-blind, comparative trial was conducted on 90 candidates for elective non-ophthalmic surgery under general anesthesia. Patients were 18 to 60 years old with the American Society of Anesthesiologists (ASA) class of I or II. Anesthesia was induced with fentanyl (1.5 mg/kg) and sodium thiopental (5 mg/kg). Patients received atracurium (0.5 mg/kg) or cisatracurium (0.15 mg/kg) two minutes prior to tracheal intubation. IOP, systolic (SBP) and diastolic blood pressure (DBP), and heart rate (HR) were measured at baseline (before medication), after medication (before intubation), and 2, 5, and 10 minutes after intubation.
  
  
  RESULTS
  In both groups IOP decreased after administration of muscle relaxants (-3.3 ± 3.6 mmHg), then increased 2 minutes after intubation (5.5 ± 4.4 mmHg), but decreased 5 (-3.3 ± 3.3 mmHg) and 10 (-0.5 ± 2.6 mmHg) minutes after intubation. IOP and SBP were significantly higher in the atracurium compared with the cisatracurium group after 2 (p < 0.001 and 0.002, respectively), 5 (p < 0.001 and 0.012, respectively), and 10 (p = 0.02 and 0.048, respectively) minutes after intubation.
  
  
  CONCLUSIONS
  Compared with atracurium, administration of cisatracurium can better prevent the increase of IOP following tracheal intubation in general anesthesia. The observed difference might be related to different effects on hemodynamic variables. Application of these results in patients under ophthalmic surgery is warranted.
authors.affiliation: Associate Professor, Department of Anesthesiology, Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mitra
authors.initials: M
authors.lastname: Jabalameli
authors.forename: Hassan Ali
authors.initials: HA
authors.lastname: Soltani
authors.forename: Jalal
authors.initials: J
authors.lastname: Hashemi
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Rahimi