title: Adenosine-induced transient asystole during intracranial aneurysm surgery: indications, dosing, efficacy, and risks.
abstract: BACKGROUND
  Several flow-arrest techniques have been introduced for the treatment of complex aneurysms that cannot be treated with conventional clipping or endovascular coil embolization. Adenosine-induced transient asystole is an alternative method of flow arrest. However, given the limited number of studies that have reported on this topic, there is no consensus regarding the dose, regimen, efficacy, and potential risks of adenosine.
  
  
  METHODS
  A total of 22 aneurysms in 22 different patients that underwent adenosine-induced transient asystole during aneurismal neck clipping within the past 4 years were retrospectively reviewed. Adenosine was administrated intravenously in a test-incremental manner (starting with 6-12 mg and then giving additional doses as needed) in 11 patients and in an estimated manner (pre-calculated as 0.3-0.4 mg/kg) in 11 patients.
  
  
  RESULTS
  Overall, the study consisted of 18 unruptured saccular aneurysms, three ruptured saccular aneurysms, and a ruptured pseudoaneurysm. Adenosine-induced transient asystole was used in cases of temporary clipping inability, wide necked aneurysm, deep-seated aneurysm, or a thin aneurysm wall. The number of administrations, dose (mg/kg in ideal body weight) and duration of asystole were 1-4 (mean, 2.3) times, 0.08-1.27 (mean, 0.36) mg/kg and 0-30 (mean 13) seconds in the test-incremental manner and 1-2 (mean, 1.09) times, 0.24-0.42 (mean, 0.34) mg/kg and 13-41 (mean, 24) seconds in the estimated manner, respectively. There was a linear relationship between the dose and the duration of asystole. Twenty out of 22 aneurysms were clipped successfully with adenosine-induced transient asystole. However, in the other two cases, additional suction decompression was required for the final clipping. Adenosine-related cardiologic complications occurred in two cases of self-limited atrial fibrillation during restoration of the cardiac rhythm.
  
  
  CONCLUSIONS
  In our experience, adenosine-induced transient asystole was safe and helpful for satisfactory clipping of a complicated aneurysm. An estimated dose injection of adenosine was more convenient than the test-incremental method and did not result in serious cardiologic problems.
authors.affiliation: Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.|Department of Neurosurgery, Kyung Hee University College of Medicine, Seoul, Korea.
authors.forename: Sung Ho
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea. bdkwun@amc.seoul.kr.
authors.forename: Byung Duk
authors.initials: BD
authors.lastname: Kwun
authors.affiliation: Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Joung Uk
authors.initials: JU
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jeong-Hyun
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
authors.forename: Jae Sung
authors.initials: JS
authors.lastname: Ahn
authors.affiliation: Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
authors.forename: Wonhyoung
authors.initials: W
authors.lastname: Park
authors.affiliation: Department of Neurosurgery, College of Medicine, Dankook University, Cheonan, Korea.
authors.forename: Jung-Ho
authors.initials: JH
authors.lastname: Yun
mesh_terms: D000241:Adenosine / Q000008:administration & dosage / Q000494:pharmacology*; D000328:Adult; D005260:Female; D006324:Heart Arrest, Induced / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D002532:Intracranial Aneurysm / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000379:methods*; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000379:methods*
chemical_list: D000241:Adenosine
keywords: Adenosine; Aneurysm; Asystole; Brain; Complication; Surgery