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Canadian Journal of Anesthesia 53:357-362 (2006)
© Canadian Anesthesiologists' Society, 2006
General Anesthesia

Remifentanil versus propofol for radio frequency treatment of atrial flutter

[Rémifentanil versus propofol pour le traitement des flutters auriculaires par radiofréquences]

Pierre Lena, MD*, Claude Jean Mariottini, MD*, Nobert Balarac, MD*, Jean Jacques Arnulf, MD*, Alain Mihoubi, MD* and René Martin, MD FRCP{dagger}

* From the Departments of Anesthesia and Cardiology, Institut Arnault Tzanck, Saint Laurent du Var, France; and the
{dagger} Department of Anesthesiology, University of Sherbrooke, Sherbrooke, Québec, Canada.

Address correspondence to: Dr. Pierre Lena, Institut Arnault Tzanck, Saint Laurent du Var, France. E-mail: pierre.lena{at}wanadoo.fr


   Abstract
TOP
 Abstract
Introduction
 Methods
 Results
 Discussion
 References
 
Purpose: Radio frequency treatment in cardiology generates short acute pain during the heating process. The present study evaluates two techniques used for sedation/analgesia for this procedure.

Methods: Two groups of 20 patients each were studied prospectively. Patients were randomized to receive sedation for the procedure using either a patient-controlled analgesia device with remifentanil (Group R), or a target controlled infusion of propofol (Group P). Patients in Group R had a basal infusion of remifentanil 0.02–0.04 µg·kg–1·min–1 with self administered bolus doses of 0.3 µg·kg–1 iv every minute as required, with a delivery time greater than 30 sec. Patients in Group P had an initial plasma target concentration set at 3–4 µg·mL–1

Results: Sedation scores were significantly higher in Group P, and two patients required supplementation with remifentanil and insertion of an laryngeal mask airway. Pain scores were higher in Group R, and two patients experienced muscular rigidity, one with transient apnea. Systolic blood pressure decreased significantly in Group P, and at the end of the procedure, PaCO2 values were higher in that group (P < 0.01). Recovery time was significantly longer in Group P. Patient and physician satisfaction scores were similar in the two groups.

Conclusions: A basal infusion of remifentanil plus remifentanil patient controlled analgesia and target controlled infusion of propofol were adequate but not optimal techniques for sedation/analgesia for radio frequency treatment of atrial flutter.


   Introduction
TOP
 Abstract
 Introduction
Methods
 Results
 Discussion
 References
 
INTERVENTIONAL cardiology procedures provide pain of variable intensity.1,2 The physical principle behind radio frequency (RF) treatment of atrial flutter is the conversion of an electric current into a low energy diathermy, leading to tissue fibrosis. A well controlled sedation analgesia regimen during the cardiac catheterization has several advantages: it enhances patient cooperation, simplifies the procedure, and reduces operating time, thus reducing patient and staff x-ray exposure. The RF procedure in cardiology does not allow in situ analgesia, is of short duration and can generate acute pain only during the heating process. It does not require any postoperative analgesia and is usually performed on older patients.

Several anesthetic techniques may provide good operative conditions for the cardiologist, ensuring a calm and pain free patient without compromising the airway. Propofol target controlled infusion (TCI) is an iv anesthetic technique which allows the anesthesiologist to target a chosen blood concentration of the drug.3 Propofol TCI has been particularly helpful during spontaneous ventilation when upper airway control is compromised.4,5 Sedation induced with propofol is more predictable and of better quality than with midazolam, and full recovery is also faster.6,7

Patient controlled analgesia (PCA) techniques allow immediate treatment of painful stimuli.8 The phamacodynamic profile of remifentanil, unique for both its onset of action and rapid recovery, makes it very attractive to block perioperative nociceptive responses, without delaying recovery or inducing secondary apnea.9,10 The aim of the present study was to evaluate propofol TCI and remifentanil PCA for sedation and analgesia for RF treatment of atrial flutter.


   Methods
TOP
 Abstract
 Introduction
 Methods
Results
 Discussion
 References
 
This randomized double-blind (for patient and cardiologist) study was conducted after approval of the Ethical Committee of the University Hospital of Nice, and informed signed consent was obtained from every patient. Forty patients scheduled for a RF ablation of atrial flutter were studied. Exclusion factors were: RF treatment of junctional tachycardia and Wolf Parkinson White syndrome, preoperative use of opioids, inability to use PCA, heart failure, an ejection fraction of < 40%, respiratory failure, and procedures expected to last longer than two hours.

No premedication was given. Upon arrival in the operating room the patients were randomly allocated using a random numbers table to either the remifentanil Group (R), (n = 20) or the propofol Group (P), (n = 20). Group R received a continuous infusion of remifentanil 0.02–0.04 µg·kg–1·min–1 (50 µg·mL–1 solution) according to respiratory tolerance, and self administered boluses of 0.3 µg·kg–1 with a refractory period of one minute and a delivery time greater than or equal to 30 sec was allowed. The iv analgesic technique was started as soon as iv access was established and ten minutes was allowed before the procedure began. Verbal contact was maintained with the patients, and nasal oxygen was administered at a rate of 3 L·min–1

Patients in Group P received a propofol TCI infusion (1% solution). The anesthetic drug was delivered through a three-way stop cock immediately proximal to the iv cannula, with a crystalloid infusion administered at a standard rate. The initial plasma target concentration of 3–4 µg·mL–1 was reached within three minutes allowing tolerance of a Guedel airway and an oxygen face mask with reservoir at a flow rate of 15 L·min–1. To maintain blinding of the experiment, the patient’s airway in both groups was covered to the cardiologist. The target drug concentration was reduced progressively to the lowest level allowing sedation with spontaneous breathing and tolerance of the Guedel airway during the RF treatment. This system has been tested previously with capnography measurements, and ensures the absence of CO2 rebreathing.

Monitoring included continuous electrocardiogram, non-invasive automatic blood pressure (values recorded every ten minutes), oxygen saturation and consciousness assessment every ten minutes.

Sedation levels were scored on a five-point scale: 1) patient awake and orientated; 2) patient drowsy; 3) closed eyes and arousable verbally; 4) closed eyes and responding to light physical stimulus; and 5) unarousable. After the procedure, patients were discharged from the recovery room when they met the following criteria: completely awake, able to follow simple commands, stable pulse rate and blood pressure, and respiratory rate > 10 min–1. Perioperative pain was scored using a visual analogue scale ranging from 0 (no pain) to 10 (worst ever experienced pain). Patients were familiarized with this system preoperatively, and pain was evaluated every ten minutes during the procedure. Sedated patients were scored 0 in the absence of movement during electrical stimulus. Respiratory depression was defined as respiratory rate of less than 10 min–1. Arterial blood gas values were measured at the beginning of the sedation process (T1) and at the end of the RF procedure, before stopping the anesthetic infusion (T2). Patient and operator satisfaction were evaluated postoperatively on a scale ranging from 0 (not satisfied) to 10 (very satisfied).

The number of patients per group was determined according to the control of acute peroperative pain. In a pre-study survey, ten control patients presented an average pain index of 7.75 ± 1. Using these data and considering a difference in index of 1.5 as significant, with a standard deviation of 1, for {alpha} and ß error of 0.05 and 0.8, respectively, 20 patients per group were required.

Statistical calculations were done using SYSTAT 11 (SYSTAT Software, Inc, Richmond, CA, USA). Descriptive data included calculation of the mean, standard error of the mean, median, maximum and minimum values. Comparative statistics were done after checking for normal distribution. For normal distribution, unpaired Student t tests were used. Kruskal-Wallis (more than two independent groups) or Mann-Whitney (two independent groups) tests were used otherwise.

For repeated measures over time, ANOVA was used for normal distribution; Friedman statistic was used otherwise. When significance was reached with one of these tests, paired Student’s t tests with Bonferroni adjustment for multiple comparison, or the Wilcoxon matched pairs, were done. An {alpha} error of < 0.05 was considered significant. All analyses were performed on an ‘intention-to-treat’ basis.


   Results
TOP
 Abstract
 Introduction
 Methods
 Results
Discussion
 References
 
Patients in Group R were 69.5 ± 8 yr and those in Group P were 72.9 ± 12.4 yr with a sex ratio (m/f) of 12/8 and 17/3, respectively. The mean infusion requirement of remifentanil was 0.07 ± 0.04 µg· kg–1·min–1 (number of bolus = 2.85 ± 1.35) and the mean infusion requirement of propofol was 162.9 ± 75.8 µg·kg–1·min–1. The mean duration of anesthesia and the procedural times were similar in the two groups, but the time spent in the recovery room was more than twice as long in Group P (P < 0.01, TableGo).


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  		TABLE Duration of anesthesia and of radio frequency procedures. Recovery room time
 
Sedation scores were higher in Group P (P < 0.01, Figure 1Go). Two patients in that group required anesthesia with remifentanil supplementation and insertion of a laryngeal mask airway due to an agitation not compatible with the procedure.


Figure 1
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  		FIGURE 1 Visual analogue scale scores for sedation in the two groups of patients at different times of evaluation. Sedation score: p < 0.01 at all times (P > R).

 
Pain scores increased significantly in Group R at ten and 20 min (P < 0.01, Figure 2Go) and two patients in that group experienced muscular rigidity. One of these two patients had transient apnea and desaturation which rapidly reversed when remifentanil was stopped, and ventilation was assisted via bag and mask. Two patients in Group P required conversion to general anesthesia due to agitation not compatible with the procedure.


Figure 2
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  		FIGURE 2 Visual analogue scale score for pain in the two groups. Visual analogue scale: P < 0.01 (R vs P) at 10 min and P < 0.05 at 20 min.

 
Systolic blood pressure decreases were greater in Group P at ten, 20, 30, 40 min compared to the baseline values. There was a statistically significant difference between groups in systolic blood pressure at ten, 20, and 30 min (Figure 3Go). Four patients in Group R and one in Group P experienced transient oxygen desaturation (≤ 95%). Arterial oxygen saturation and PaCO2 values increased significantly in the two groups at T2, with associated respiratory acidosis (pH 7.29 ± 0.1 and 7.37 ± 0.08) in Groups P and R. PaCO2 values were significantly higher in Group P at T2 compared to Group R (Figure 4Go). Two patients from Group R experienced nausea and vomiting. The length of stay in recovery room was significantly longer in Group P (TableGo). Patient and physician satisfaction score at the end of the procedures were similar in the two groups (Figure 5Go).


Figure 3
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  		FIGURE 3 Systolic blood pressure (SBP) during the course of the procedure (mean ± SEM). *P < 0.05 at 10 min R vs P; **P < 0.01 at 20 and 30 min R vs P; *P < 0.05 at 40 min vs 0, group P; **P < 0.01 at 10, 20, and 30 min vs 0, group P.

 

Figure 4
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  		FIGURE 4 PaCO2 values recorded at two different times (mean ± SEM). **P < 0.01 T1 vs T2 for R and P. **P < 0.01 P vs R at T2.

 

Figure 5
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  		FIGURE 5 Patient and physician satisfaction scores.

 

   Discussion
TOP
 Abstract
 Introduction
 Methods
 Results
 Discussion
References
 
This study emphasizes the difficulty in providing adequate sedation and pain relief for patients undergoing RF ablation treatment. In fact, both techniques used in the present study had limitations.

Pain varied amongst patients and throughout the procedure, with rapid changes in duration and intensity of the electrical stimuli. The mean infusion rates of remifentanil (0.07 ± 0.04 µg·kg–1·min–1 including the PCA self administered boluses), were higher than initially planned. However, drug requirements were comparable to those reported by Volmanen et al.11 (0.066 µg·kg–1·min–1) for obstetrical analgesia with remifentanil PCA, and are slightly less than those reported by Bouvet et al. (0.08 µg·kg–1·min–1) for gastrointestinal endoscopic controlled sedation.12 Dilger et al.’s cumulative remifentanil requirements were lower (0.05 µg·kg–1·min–1), but patients received simultaneously propofol and a local anesthetic.13 Roelants et al. used similar doses of remifentanil in six labouring patients who received a continuous infusion of 0.05 µg·kg–1·min–1 and boluses of 25 µg, with a lock out interval of five minutes. These authors reported satisfactory analgesia without side effects.14

Acute pain score analysis showed higher scores in Group R, but sedation scores were also significantly lower in that group at all times. This contrasts with the higher sedation scores and lower pain scores observed in Group P.

In Group P, agitation that could have hampered the procedure15 was not observed at the achieved level of sedation. However, agitation has been reported by Newson et al.16 during mammary biopsy under propofol and local anesthesia.

Systolic blood pressure variations were statistically greater in Group P, although the clinical importance of this observation is modest at the achieved level of sedation. High target propofol concentrations are necessary to achieve optimal sedation during RF procedure. This was also shown by Lauwers et al.17 for sedation in regional anesthesia.

Four patients (20%) in Group R and one in Group P (5%) experienced episodes of low oxygen saturation (SpO2 < 95%). This underscores the difficulties encountered with monitoring. Despite a significant rise in PaCO2 at the end of the procedure, pulse oximetry detected only 5% of events. This shows a limitation of oxygen saturation monitoring as a sole measure of ventilatory adequacy in spontaneously breathing patients, as demonstrated by Ramsay et al.18 and capnography using an auricular sensor or a device attached to the face mask could be valuable.19 Contrary to the patients with respiratory depression in Group P, three patients in Group R with respiratory depression could be verbally stimulated by the anesthesiologist when oxygen saturation was decreasing. However, the higher PaCO2 values in Group P compared to Group R are at variance with others studies,15,17,20–22 and can be explained by higher doses of propofol administered in our investigation. Blood gas disturbances at the end of the procedure could also be partially responsible for the prolonged recovery time observed in Group P, although average procedural and anesthetic times were comparable in the two groups.

One patient in Group R suffered respiratory depression and muscular rigidity. This complication has been reported with a frequency between 5 to 41%,21–24 in patients receiving conscious sedation.

Two patients in Group P required conversion to general anesthesia due to excessive agitation and movement. The rate of conversion to general anesthesia was estimated to be 4% in Joo’s study.23 Vomiting occurred in 10% of patients in Group R and was also quoted by Mingus21 and Lauwers.17

The identified limitations of the evaluated sedation techniques give rise to consideration of optimizing drug interactions. A combined remifentanil and propofol infusion regimen taking advantage of synergistic interactions could offer distinct pharmacological advantages. An alternative to remifentanil PCA would be a TCI of remifentanil titrated to specific sedation levels. Evaluation of depth of anesthesia with bispectral index monitoring might also help to maintain a stable level of sedation. Although bispectral index monitoring has been evaluated for conscious sedation, results to date for this indication have been variable.25,26 In conclusion, we have demonstrated that a remifentanil technique combining a basal infusion and PCA boluses and propofol target infusion were adequate, but not optimal techniques for RF ablation.


   Acknowledgments
 
The authors thank Dr. Jean-Yves Bigeon for his helpful assistance in data collection and data analysis.


   Footnotes
 
Assessed June 13, 2005. Revision accepted for publication August 30, 2005. Final revision accepted October 31, 2005

Competing interests: None declared.


   References
TOP
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 
1 Jeremias A, Kutscher S, Haude M, et al. Nonischemic chest pain induced by coronary interventions. A prospective study comparing coronary angioplasty and stent implantation. Circulation 1998; 98: 2656–8.[Abstract/Free Full Text]

2 Wellens HJ. Catheter ablation for cardiac arrhythmias. N Engl J Med 2004; 351: 1172–4.[Free Full Text]

3 Servin FS. TCI compared with manually controlled infusion of propofol: a multicentre study. Anaesthesia 1998; 53: 82–6.

4 MacKenzie RE, MacFadzean WA. A difficult airway managed by computer? (Letter). Anaesthesia 1992; 47: 633–4.[Medline]

5 Donnelly JA, Webster RE. Computer-controlled anaesthesia in the management of bronchopleural fistula. Anaesthesia 1991; 46: 383–4.[Medline]

6 Kestin IG, Harvey PB, Nixon C. Psychomotor recovery after three methods of sedation during spinal anaesthesia. Br J Anaesth 1990; 64: 675–81.[Abstract/Free Full Text]

7 White PF, Negus JB. Sedative infusions during local and regional anesthesia: a comparison of midazolam and propofol. J Clin Anesth 1991; 3: 32–9.[Medline]

8 Macintyre PE. Safety and efficacy of patient-controlled analgesia. Br J Anaesth 2001; 87: 36–46.[Abstract/Free Full Text]

9 Hogue CW, Bowdle TA, O’Leary C, et al. A multicenter evaluation of total intravenous anesthesia with remifentanil and propofol for elective inpatient surgery. Anesth Analg 1996; 83: 279–85.[Abstract]

10 Servin F. Remifentanil; from pharmacological properties to clinical practice. Adv Exp Med Biol 2003; 523: 245–60.[Medline]

11 Volmanen P, Akural EI, Raudaskoski T, Alahuhta S. Remifentanil in obstetric analgesia: a dose-finding study. Anesth Analg 2002; 94: 913–7.[Abstract/Free Full Text]

12 Bouvet L, Allaouchiche B, Duflo F, Debon R, Chassard D, Boselli E. Le rémifentanil est une alternative efficace au propofol pour l’analgésie auto-contrôlée en endoscopie digestive. Can J Anesth 2004; 51: 122–5.[Abstract/Free Full Text]

13 Dilger JA, Sprung J, Maurer W, Tetzlaff J. Remifentanil provides better analgesia than alfentanil during breast biopsy surgery under monitored anesthesia care. Can J Anesth 2004; 51: 20–4.[Abstract/Free Full Text]

14 Roelants F, De Franceschi E, Veyckemans F, Lavand’homme P. Patient-controlled intravenous analgesia using remifentanil in the parturient. Can J Anesth 2001; 48: 175–8.[Abstract/Free Full Text]

15 Passot S, Servin F, Allary R, et al. Target-controlled versus manually-controlled infusion of propofol for direct laryngoscopy and bronchoscopy. Anesth Analg 2002; 94: 1212–6.[Abstract/Free Full Text]

16 Newson C, Joshi GP, Victory R, White PF. Comparison of propofol administration techniques for sedation during monitored anesthesia care. Anesth Analg 1995; 81: 486–91.[Abstract]

17 Lauwers MH, Vanlersberghe C, Camu F. Comparison of remifentanil and propofol infusions for sedation during regional anesthesia. Reg Anesth Pain Med 1998; 23: 64–70.[Medline]

18 Ramsay MA, Macaluso A, Tillmann Hein H, Cancemi E. Use of remifentanil in patients breathing spontaneously during monitored anesthesia care and in the management of acute postoperative care. Anesthesiology 1998; 88: 1124–6.[Medline]

19 Dominguez E. Carbon dioxide monitoring during deep conscious sedation using nasopharyngeal airways (Letter). Anesthesiology 1999; 91: 1177–8.[Medline]

20 Holas A, Krafftt P, Marcovic M, Quehenberger F. Remifentanil, propofol or both for conscious sedation during eye surgery under regional anaesthesia. Eur J Anaesthesiol 1999; 16: 741–8.[Medline]

21 Mingus ML, Monk TG, Gold MI, Jenkins W, Roland C. Remifentanil versus propofol as adjuncts to regional anesthesia. Remifentanil 3010 Study Group. J Clin Anesth 1998; 10: 46–53.[Medline]

22 Pavlin DJ, Coda B, Shen DD, et al. Effects of combining propofol and alfentanil on ventilation, analgesia, sedation, and emesis in human volunteers. Anesthesiology 1996; 84: 23–37.[Medline]

23 Joo HS, Perks WJ, Kataoka MT, Errett L, Pace K, Honey RJ. A comparison of patient-controlled sedation using either remifentanil or remifentanil-propofol for shock wave lithotripsy. Anesth Analg 2001; 93: 1227–32.[Abstract/Free Full Text]

24 Smith I, Avramov MN, White PF. A comparison of propofol and remifentanil during monitored anesthesia care. J Clin Anesth 1997; 9: 148–54.[Medline]

25 Vivien B, Di Maria S, Ouattara A, Langeron O, Coriat P, Riou B. Overestimation of bispectral index in sedated intensive care unit patients revealed by administration of muscle relaxant. Anesthesiology 2003; 99: 9–17.[Medline]

26 Coimbra C, Choiniere M, Hemmerling TM. Patient-controlled sedation using propofol for dressing changes in burn patients: a dose-finding study. Anesth Analg 2003; 97: 839–42.[Abstract/Free Full Text]





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