title: Quality of analgesia when air versus saline is used for identification of the epidural space in the parturient.
abstract: OBJECTIVE
  Identification of the epidural space is often performed using the loss-of-resistance technique (LOR), commonly with air or saline. The effect of air or saline on the quality of labor epidural analgesia has not been adequately studied.
  
  
  METHODS
  Women who requested labor epidural analgesia were randomly assigned to 1 of 2 groups depending on the syringe contents used for the LOR technique and injected into the epidural space. In the air group (n = 80) the anesthesiologist used 2 mL of air, and in the saline group (n = 80) the anesthesiologist used 2 mL of 0.9% saline. After LOR was obtained, a multiorifice epidural catheter was threaded 5 cm into the epidural space and 13 mL of bupivacaine 0.25% was administered in divided doses. The success of the epidural block was determined by asking the patient if she required additional medication 15 minutes later. The occurrence of paresthesias and intravascular or subarachnoid catheters was noted.
  
  
  RESULTS
  In the air group, 36% of patients requested additional pain medication, and in the saline group 19% requested additional medication (P =.022). We were not able to find a statistically significant difference between groups in the incidence of paresthesias (42% air v 51% saline), intravascular catheters (5% air v 8% saline), or subarachnoid catheters (0 in both groups).
  
  
  CONCLUSIONS
  Using 0.9% saline for the LOR technique is associated with better analgesia as compared with air for labor analgesia, and this advantage should be considered when selecting the syringe contents for the LOR technique.
authors.affiliation: Department of Anesthesiology, Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, NY 10029-6574, USA. ybeilin@mountsinai.org
authors.forename: Y
authors.initials: Y
authors.lastname: Beilin
authors.forename: I
authors.initials: I
authors.lastname: Arnold
authors.forename: C
authors.initials: C
authors.lastname: Telfeyan
authors.forename: H H
authors.initials: HH
authors.lastname: Bernstein
authors.forename: S
authors.initials: S
authors.lastname: Hossain
mesh_terms: D000293:Adolescent; D000328:Adult; D015360:Analgesia, Epidural; D016362:Analgesia, Obstetrical; D004824:Epidural Space; D005260:Female; D006801:Humans; D011247:Pregnancy; D011446:Prospective Studies; D012965:Sodium Chloride / Q000008:administration & dosage*
chemical_list: D012965:Sodium Chloride