title: Subcutaneous administration of nitroglycerin to facilitate radial artery cannulation.
abstract: OBJECTIVE
  To study the effect of sublingual versus subcutaneous nitroglycerin on radial artery spasm caused by failed access attempts.
  
  
  BACKGROUND
  Radial artery spasm is the leading reason for failed radial access. We studied the efficacy of systemic versus local nitroglycerin in relieving radial artery spasm caused by needle entry resulting in failed cannulation.
  
  
  METHODS
  Fifty-two consecutive patients were studied. All patients had failed attempt at radial artery cannulation, resulting in loss of radial pulse. Patients were divided in three groups, group I (n = 11), observed without additional treatment, group II (n = 20), administered 400 mcg of sublingual nitroglycerin, and group III (n = 21), administered 400 mcg of subcutaneous nitroglycerin at the site of the lost radial pulse. All patients were monitored for the return of radial pulse. Demographics, hemodynamics, and time to return of radial pulse as well as ability to successfully cannulate the radial artery were recorded.
  
  
  RESULTS
  Seventy-two percent of group I patients, 90% of group II patients, and 100% of group III patients had re-establishment of radial pulse. The time to return of radial pulse was significantly shorter for group III compared with that for group II (3 +/- 1 min vs. 8 +/- 1 min respectively, P < 0.001). Re-establishment of radial pulse was faster in group II and group III compared with that in group I (18 +/- 5 min, P < 0.001). Systolic blood pressure changes and headaches were less common in group III.
  
  
  CONCLUSIONS
  Subcutaneous administration of nitroglycerin is superior in facilitating radial artery cannulation after initial failed attempt.
authors.affiliation: Department of Cardiology, Mercy Hospital and Community Medical Center, Scranton, Pennsylvania, USA. drpancholy@yahoo.com
authors.forename: Samir B
authors.initials: SB
authors.lastname: Pancholy
authors.forename: John
authors.initials: J
authors.lastname: Coppola
authors.forename: Tejas
authors.initials: T
authors.lastname: Patel
mesh_terms: D000286:Administration, Sublingual; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001794:Blood Pressure / Q000187:drug effects; D002404:Catheterization / Q000379:methods; D005260:Female; D006801:Humans; D007279:Injections, Subcutaneous; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage*; D011674:Pulse; D017534:Radial Artery / Q000187:drug effects* / Q000503:physiopathology; D012107:Research Design; D016896:Treatment Outcome; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000008:administration & dosage*
chemical_list: D014665:Vasodilator Agents; D005996:Nitroglycerin