A randomized clinical trial of continuous flow nitrous oxide and nalbuphine infusion for sedation of patients during radiofrequency atrial flutter ablation.
BACKGROUND
In patients with common atrial flutter (CAF), radiofrequency ablation (RFA) causes discomfort. Patients undergoing RFA often feel pain which is difficult to control as the mechanisms are unclear.


OBJECTIVE
Inhaled nitrous oxide (N2O) is a potent sedative-analgesic-anxiolytic agent that may relieve anxiety and discomfort during CAF ablation.


RESULTS
In a prospective randomized study, the effect of Inhaled N2O was compared with that of intravenous sedation with Nalbuphine during CAF ablation in 76 patients (64 +/- 13 years, 56 men). We used a 24 pole mapping catheter around the tricuspid annulus and a 8-mm tip ablation catheter for each patient. Forty-two patients (group 1) underwent radiofrequency (RF) application to the cavotricuspid isthmus 5 minutes after the beginning of inhalation of a (50% N2O/50% O2) mixture. Thirty-four patients (group 2), underwent the first RF application 15 minutes after the end of an infusion of Nalbuphine (20 mg delivered over 15 minutes). Ablation-related anxiety and discomfort were assessed using a visual analog scale (VAS) ranging from 0 to 100 mm, with 0 correlating to the statement "no pain at all" and 100 with "the worst possible pain." The VAS score was determined at the end of each application. The number of RF applications (group 1; 10 +/- 8 vs group 2; 11 +/- 6, P = NS) and procedure duration (group 1; 75 +/- 53 minutes vs group 2; 72 +/- 45 minutes, P = NS), were similar for the two groups. N(2)O sedation compared with nalbuphine infusion reduced VAS for anxiety (10 mm +/- 8 vs 58 mm +/- 22, P < 0.05) and for discomfort (18 mm +/- 9 vs 45 mm +/- 34, P < 0.01), respectively. Although there was more frequent vomiting in group 1; 7 of 42 (17%) than in group 2; 3 of 34 (9%), P < 0.05, patients were less likely to have hypotension during the procedure 1 of 42 (2.5%) versus 4 of 34 (12%), P < 0.05, respectively.


CONCLUSIONS
Inhalation of a (50% N2O/50% O2) mixture during RF ablation for atrial flutter is a safe and efficient way to reduce anxiety and discomfort caused by RF applications.
Laurent
Gabriel
G
Department of Cardiology, University Hospital Dijon, France. nathalie@free.fr
Bertaux
Géraldine
G
Martel
Alexandra
A
Fraison
Michel
M
Fromentin
Stéphane
S
Gonzalez
Stéphanie
S
Pierre
François Saint
FS
Wolf
Jean Eric
JE
D000280:Administration, Inhalation; D000701:Analgesics, Opioid / Q000008:administration & dosage; D018685:Anesthetics, Inhalation / Q000008:administration & dosage; D001007:Anxiety / Q000209:etiology / Q000517:prevention & control*; D001282:Atrial Flutter / Q000150:complications / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects*; D016292:Procedural Sedation / Q000379:methods*; D004338:Drug Combinations; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D009266:Nalbuphine / Q000008:administration & dosage*; D009609:Nitrous Oxide / Q000008:administration & dosage*; D010146:Pain / Q000209:etiology / Q000517:prevention & control*; D016896:Treatment Outcome
D000701:Analgesics, Opioid; D018685:Anesthetics, Inhalation; D004338:Drug Combinations; D009609:Nitrous Oxide; D009266:Nalbuphine