title: Adenosine-induced ventricular asystole to induce transient profound systemic hypotension in patients undergoing endovascular therapy. Dose-response characteristics.
abstract: BACKGROUND
  Adenosine-induced asystole has been used to induce transient systemic hypotension for various vascular procedures. Dose-response characteristics of adenosine-induced ventricular asystole have not been determined.
  
  
  METHODS
  During endovascular embolization of cerebral arteriovenous malformations, the authors performed a series of adenosine test injections to establish a dose-response relation in each patient. After an interval of 3-10 min, the dose was escalated by 10-20 mg for each injection to achieve an end point of 20-30 s of stable mean arterial pressure (MAP) reduction to 25-30 mmHg. All patients received constant infusion of nitroprusside (approximately 1 microgram. kg-1. min-1) throughout the procedure.
  
  
  RESULTS
  The authors studied four adult patients (age, 22-44 yr; two patients had two separate procedures) and one pediatric patient (age, 4 yr). Twenty-three adenosine injections resulted in measurable asystole. The adenosine dose was 0. 98 +/- 0.40 mg/kg (mean +/- SD), and the dose range was 0.24-1.76 mg/kg (6-90 mg). The duration of asystole, MAP < 30 mmHg, and MAP < 50 mmHg, were 8 +/- 3 s, 18 +/- 12 s, and 50 +/- 29 s, respectively. The minimum MAP and the MAP for the first 20 s were 16 +/- 3 mmHg and 30 +/- 9 mmHg, respectively. There was a linear relation between adenosine dose and the duration of hypotension with MAP < 30 mmHg and MAP < 50 mmHg.
  
  
  CONCLUSIONS
  In the dose range studied, a series of adenosine test injections can be used to determine optimal adenosine dose for induction of transient profound hypotension.
authors.affiliation: Departments of Anesthesia and Perioperative Care, Neurosurgery, and Neurology, University of California-San Francisco, San Francisco, California, USA.
authors.forename: T
authors.initials: T
authors.lastname: Hashimoto
authors.forename: W L
authors.initials: WL
authors.lastname: Young
authors.forename: B D
authors.initials: BD
authors.lastname: Aagaard
authors.forename: S
authors.initials: S
authors.lastname: Joshi
authors.forename: N D
authors.initials: ND
authors.lastname: Ostapkovich
authors.forename: J
authors.initials: J
authors.lastname: Pile-Spellman
mesh_terms: D000241:Adenosine / Q000627:therapeutic use*; D000328:Adult; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004621:Embolization, Therapeutic / Q000379:methods*; D004659:Enbucrilate / Q000627:therapeutic use; D005260:Female; D006324:Heart Arrest, Induced / Q000379:methods*; D006801:Humans; D007022:Hypotension / Q000139:chemically induced; D002538:Intracranial Arteriovenous Malformations / Q000628:therapy*; D008297:Male; D014665:Vasodilator Agents / Q000627:therapeutic use*; D016276:Ventricular Function / Q000187:drug effects
chemical_list: D014665:Vasodilator Agents; D004659:Enbucrilate; D000241:Adenosine