title: Comparison of short-axis out-of-plane versus long-axis in-plane ultrasound-guided radial arterial cannulation in adult patients: a randomized controlled trial.
abstract: The current available literature is not unanimous in reporting the utility of short-axis and long-axis techniques for radial artery cannulation in both adults and children. This study was designed to compare short-axis out-of-plane (SA-OOP) and long-axis in-plane (LA-IP) techniques in ultrasound-guided radial artery cannulation in adults.
  
  
  
  In this prospective randomized controlled trial, 150 adult patients of American Society of Anesthesiologists physical status I-III aged between 18 and 70 years were included. All patients were randomized into two groups (group SA-OOP) and (group LA-IP) of 75 each undergoing ultrasound-guided radial artery cannulation. The primary outcome was successful cannulation in the first attempt. Secondary outcomes included antero-posterior arterial diameter, skin-to-artery distance, ultrasonic localization time, cannulation time, no of attempts to cannulate artery, cannula insertion failure, and vascular complications.
  
  
  
  First-attempt arterial cannulation was successful in 80 % of patients in the SA-OOP group as opposed to 82.6 % patients in the LA-IP group (p = 0.67). The time to cannulate the artery was similar between the two groups, but the time to localize artery was significantly higher in the long-axis technique (p < 0.001).
  
  
  
  The first-attempt cannulation success rate and cannulation time in adult patients are similar in ultrasound-guided radial artery cannulation with both short-axis as well as long-axis techniques. Trial registration Clinical Trial Registry of India (CTRI/2015/02/005552).
authors.affiliation: Anesthesia Department, Post Graduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh, 160012, India. sameersethi29@gmail.com.
authors.forename: Sameer
authors.identifier: http://orcid.org/0000-0002-8429-9163
authors.initials: S
authors.lastname: Sethi
authors.affiliation: Anesthesia Department, Post Graduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh, 160012, India.
authors.forename: Souvik
authors.initials: S
authors.lastname: Maitra
authors.affiliation: Anesthesia Department, Post Graduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh, 160012, India.
authors.forename: Vikas
authors.initials: V
authors.lastname: Saini
authors.affiliation: Anesthesia Department, Post Graduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh, 160012, India.
authors.forename: Tanvir
authors.initials: T
authors.lastname: Samra
authors.affiliation: Anesthesia Department, Post Graduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh, 160012, India.
authors.forename: S K
authors.initials: SK
authors.lastname: Malhotra
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000453:epidemiology; D002406:Catheterization, Peripheral / Q000379:methods*; D004868:Equipment Failure; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017534:Radial Artery; D012867:Skin; D018084:Ultrasonography, Interventional / Q000379:methods*; D055815:Young Adult
keywords: Cannulation; Long-axis in-plane technique; Radial artery; Short-axis out-of-plane technique; Ultrasound