title: Vein pretreatment with magnesium sulfate to prevent pain on injection of propofol is not justified.
abstract: OBJECTIVE
  Propofol produces anesthesia with rapid recovery. However, it causes pain or discomfort on injection. A number of techniques have been tried for minimizing propofol-induced pain with variable results. We have compared the efficacy of magnesium and lidocaine for the prevention of propofol induced pain.
  
  
  METHODS
  Three hundred ASA I and II adults undergoing elective surgery were randomly assigned into three groups of 100 each. Group I received magnesium sulfate 1 g, Group II received lidocaine 2% (40 mg) and Group III received normal saline, all in a volume of 2 mL and accompanied by venous occlusion for one minute. Induction with propofol 2.5 mg.kg(-1) was accomplished following the release of venous occlusion. Pain was assessed on a four-point scale: 0 = no pain, 1 = mild pain, 2 = moderate pain, and 3 = severe pain at the time of pretreatment and propofol injection. Results were analyzed by 'Z' test. A P value of < 0.05 was considered as significant.
  
  
  RESULTS
  Pain during i.v. pretreatment with magnesium was 31% as compared to 2% for both the lidocaine and control groups (P < 0.05). Seventy-six percent of patients in the control group had pain during i.v. propofol as compared to 32% and 42% in the magnesium and the lidocaine groups respectively (P < 0.05). Lidocaine and magnesium pretreatment were equally effective in attenuating pain during the propofol injection (P > 0.05).
  
  
  CONCLUSIONS
  Intravenous magnesium and lidocaine pretreatment are equally effective in attenuating propofol-induced pain. However, magnesium pretreatment itself causes pain. Therefore, there is no justification in the use of magnesium pretreatment for attenuating pain associated with i.v. propofol.
authors.affiliation: Department of Anesthesia, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India. aagarwal@sgpgi.ac.in
authors.forename: Anil
authors.initials: A
authors.lastname: Agarwal
authors.forename: Sanjay
authors.initials: S
authors.lastname: Dhiraj
authors.forename: Mehdi
authors.initials: M
authors.lastname: Raza
authors.forename: Ravinder
authors.initials: R
authors.lastname: Pandey
authors.forename: Chandra Kant
authors.initials: CK
authors.lastname: Pandey
authors.forename: Prabhat K
authors.initials: PK
authors.lastname: Singh
authors.forename: Uttam
authors.initials: U
authors.lastname: Singh
authors.forename: Devendra
authors.initials: D
authors.lastname: Gupta
mesh_terms: D000293:Adolescent; D000328:Adult; D000700:Analgesics / Q000008:administration & dosage / Q000009:adverse effects; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects; D000779:Anesthetics, Local / Q000008:administration & dosage; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D007275:Injections, Intravenous / Q000009:adverse effects; D008012:Lidocaine / Q000008:administration & dosage*; D008278:Magnesium Sulfate / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000517:prevention & control*; D010147:Pain Measurement; D011229:Preanesthetic Medication / Q000379:methods*; D015742:Propofol / Q000008:administration & dosage* / Q000009:adverse effects*; D012965:Sodium Chloride / Q000008:administration & dosage; D016896:Treatment Outcome
chemical_list: D000700:Analgesics; D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D012965:Sodium Chloride; D008278:Magnesium Sulfate; D008012:Lidocaine; D015742:Propofol