Safety of nurse-administered deep sedation for defibrillator implantation in the electrophysiology laboratory

Old Is (Not) Gold: Midazolam Monotherapy versus Midazolam Plus Fentanyl for Sedation during Cardiac Catheterization

Objective

We aimed to study the differences in perception of pain during cardiac catheterization with midazolam monotherapy compared to the current standard of midazolam plus fentanyl.

Background

Procedural sedation is important to ensure comfort and safety in patients undergoing left heart catheterization. Despite the widespread use of midazolam and fentanyl for procedural sedation, the effectiveness of this dual agent approach to sedation has never been studied in comparison to midazolam monotherapy.

Methods

A total of 129 patients undergoing sedation for outpatient elective cardiac catheterization were randomly assigned to either midazolam monotherapy (n = 69) or combination of midazolam and fentanyl (n = 60). The primary outcome was assessment of pain perception prior to discharge by patient completion of a pain questionnaire. Participants were asked if they experienced any pain during their procedure (yes/no) and, if yes, asked to rate their overall pain level using a 10-point Likert scale that ranged from 1 (minimal pain) to 10 (worst pain imaginable).

Results

Most patients (n = 94, 73%) reported no pain during their procedure. Patients sedated with midazolam monotherapy reported similar average pain scores compared to patients sedated with the combination of midazolam and fentanyl (1.1 vs. 1.1, p=0.95).

Conclusions

Among patients undergoing elective cardiac catheterization, no significant differences in pain scores were noted between sedation with midazolam alone compared to midazolam and fentanyl. Due to fentanyl's unfavorable interaction with P2Y12 agents, increased costs, and addiction potential, it is imperative that cardiologists revisit the role of effective procedural sedation with a single agent and avoid the use of fentanyl.

A review of sedation scales for the cardiac catheterization laboratory

PURPOSE

Sedation scales have the potential to facilitate effective procedural sedation and analgesia in the cardiac catheterization laboratory (CCL). For this potential to become realized, a scale that is suitable for use in the CCL either needs to be identified or developed.

DESIGN

A structured review strategy was applied.

METHODS

To identify sedation scales, a review of Medline and CINHAL was conducted.

FINDINGS

One sedation scale for the CCL, the North American Society for Pacing and Electrophysiology Sedation Scale, and 15 intensive care unit (ICU) scales met the inclusion and exclusion criteria. Analysis of the scale's item structures and psychometric properties was then performed.

CONCLUSION

None of these scales were deemed suitable for use in the CCL. As such, further research is required to develop a new scale. The new scale should consist of more than one item to make it more effective for tracking the patient's response to medications. Specific tests required to conduct a rigorous evaluation of the new scale's psychometric properties are outlined in this article.

Sedation for electrophysiological procedures

Administration of intravenous sedation (IVS) has become an integral component of procedural cardiac electrophysiology. IVS is employed in diagnostic and ablation procedures for transcutaneous treatment of cardiac arrhythmias, electrical cardioversion of arrhythmias, and the insertion of implantable electronic devices including pacemakers, defibrillators, and loop recorders. Sedation is frequently performed by nursing staff under the supervision of the proceduralist and in the absence of specialist anesthesiologists. The sedation requirements vary depending on the nature of the procedure. A wide range of sedation techniques have been reported with sedation from the near fully conscious to levels approaching that of general anesthesia. This review examines the methods employed and outcomes associated with reported sedation techniques. There is a large experience with the combination of benzodiazepines and narcotics. These drugs have a broad therapeutic range and the advantage of readily available reversal agents. More recently, the use of propofol without serious adverse events has been reported. The results provide a guide regarding the expected outcomes of these approaches. The complication rate and need for emergency assistance is low in reported series where sedation is administered by nonspecialist anesthesiology staff.

Issues and challenges associated with nurse-administered procedural sedation and analgesia in the cardiac catheterisation laboratory: a qualitative study

AIMS AND OBJECTIVES

To explore issues and challenges associated with nurse-administered procedural sedation and analgesia in the cardiac catheterisation laboratory from the perspectives of senior nurses.

BACKGROUND

Nurses play an important part in managing sedation because the prescription is usually given verbally directly from the cardiologist who is performing the procedure and typically, an anaesthetist is not present.

DESIGN

A qualitative exploratory design was employed.

METHODS

Semi-structured interviews with 23 nurses from 16 cardiac catheterisation laboratories across four states in Australia and also New Zealand were conducted. Data analysis followed the guide developed by Braun and Clark to identify the main themes.

RESULTS

Major themes emerged from analysis regarding the lack of access to anaesthetists, the limitations of sedative medications, the barriers to effective patient monitoring and the impact that the increasing complexity of procedures has on patients' sedation requirements.

CONCLUSIONS

The most critical issue identified in this study is that current guidelines, which are meant to apply regardless of the clinical setting, are not practical for the cardiac catheterisation laboratory due to a lack of access to anaesthetists. Furthermore, this study has demonstrated that nurses hold concerns about the legitimacy of their practice in situations when they are required to perform tasks outside of clinical practice guidelines. To address nurses' concerns, it is proposed that new guidelines could be developed, which address the unique circumstances in which sedation is used in the cardiac catheterisation laboratory.

RELEVANCE TO CLINICAL PRACTICE

Nurses need to possess advanced knowledge and skills in monitoring for the adverse effects of sedation. Several challenges impact on nurses' ability to monitor patients during procedural sedation and analgesia. Preprocedural patient education about what to expect from sedation is essential.

Nurse-administered procedural sedation and analgesia in the cardiac catheter laboratory: an integrative review

OBJECTIVES

To identify and appraise the literature concerning nurse-administered procedural sedation and analgesia in the cardiac catheter laboratory.

DESIGN AND DATA SOURCES

An integrative review method was chosen for this study. MEDLINE and CINAHL databases as well as The Cochrane Database of Systematic Reviews and the Joanna Briggs Institute were searched. Nineteen research articles and three clinical guidelines were identified.

RESULTS

The authors of each study reported nurse-administered sedation in the CCL is safe due to the low incidence of complications. However, a higher percentage of deeply sedated patients were reported to experience complications than moderately sedated patients. To confound this issue, one clinical guideline permits deep sedation without an anaesthetist present, while others recommend against it. All clinical guidelines recommend nurses are educated about sedation concepts. Other findings focus on pain and discomfort and the cost-savings of nurse-administered sedation, which are associated with forgoing anaesthetic services.

CONCLUSIONS

Practice is varied due to limitations in the evidence and inconsistent clinical practice guidelines. Therefore, recommendations for research and practice have been made. Research topics include determining how and in which circumstances capnography can be used in the CCL, discerning the economic impact of sedation-related complications and developing a set of objectives for nursing education about sedation. For practice, if deep sedation is administered without an anaesthetist present, it is essential nurses are adequately trained and have access to vital equipment such as capnography to monitor ventilation because deeply sedated patients are more likely to experience complications related to sedation. These initiatives will go some way to ensuring patients receiving nurse-administered procedural sedation and analgesia for a procedure in the cardiac catheter laboratory are cared for using consistent, safe and evidence-based practices.

Safe and effective use of conscious sedation for defibrillation threshold testing during ICD implantation

BACKGROUND

Over a period of years general anesthesia has been a standard anesthetic technique for defibrillation threshold (DFT) testing at the time of implant. DFT testing without general anesthesia cover has gained limited acceptance. Use of local anesthesia combined with deep sedation for DFT testing might facilitate and simplify these procedures by reducing the procedural time, staff time, avoiding inefficient service in organizing anesthetic cover; thereby improving patient compliance.

OBJECTIVE

The objective of this study was to evaluate feasibility, safety and efficacy of conscious sedation for DFT testing during Implantable cardioverter defibrillators (ICD) implantation.

METHOD

Data of 87 non-selected patients who achieved adequate sedation with titrated doses of midazolam and pethidine were analyzed retrospectively. These medications were administered by a circulating nurse under the supervision of the implanting physicians. All hemodynamic measures, treatment and complications were monitored and recorded throughout the procedure.

RESULTS

A retrospective analysis of data from 87 patients who underwent ICD implantation and DFT testing under conscious sedation at our center was reported. The mean dose of midazolam and pethidine administered was 4.9 ± 1.8 and 47.7 ± 20 mg, respectively. During the period of conscious sedation, no patient depicted episode of sustained apnea. No major complication or mortality was reported.

CONCLUSION

Use of conscious sedation as an alternative to the use of general anesthesia for DFT testing during ICD implantation is found to be feasible, safe and effective, with an added advantage of reduced procedural time and improved patient compliance.

The dilemma of ICD implant testing

Ventricular fibrillation (VF) has been induced at implantable cardioverter defibrillator (ICD) implant to ensure reliable sensing, detection, and defibrillation. Despite its risks, the value was self-evident for early ICDs: failure of defibrillation was common, recipients had a high risk of ventricular tachycardia (VT) or VF, and the only therapy for rapid VT or VF was a shock. Today, failure of defibrillation is rare, the risk of VT/VF is lower in some recipients, antitachycardia pacing is applied for fast VT, and vulnerability testing permits assessment of defibrillation efficacy without inducing VF in most patients. This review reappraises ICD implant testing. At implant, defibrillation success is influenced by both predictable and unpredictable factors, including those related to the patient, ICD system, drugs, and complications. For left pectoral implants of high-output ICDs, the probability of passing a 10 J safety margin is approximately 95%, the probability that a maximum output shock will defibrillate is approximately 99%, and the incidence of system revision based on testing is < or = 5%. Bayes' Theorem predicts that implant testing identifies < or = 50% of patients at high risk for unsuccessful defibrillation. Most patients who fail implant criteria have false negative tests and may undergo unnecessary revision of their ICD systems. The first-shock success rate for spontaneous VT/VF ranges from 83% to 93%, lower than that for induced VF. Thus, shocks for spontaneous VT/VF fail for reasons that are not evaluated at implant. Whether system revision based on implant testing improves this success rate is unknown. The risks of implant testing include those related to VF and those related to shocks alone. The former may be due to circulatory arrest alone or the combination of circulatory arrest and shocks. Vulnerability testing reduces risks related to VF, but not those related to shocks. Mortality from implant testing probably is 0.1-0.2%. Overall, VF should be induced to assess sensing in approximately 5% of ICD recipients. Defibrillation or vulnerability testing is indicated in 20-40% of recipients who can be identified as having a higher-than-usual probability of an inadequate defibrillation safety margin based on patient-specific factors. However, implant testing is too risky in approximately 5% of recipients and may not be worth the risks in 10-30%. In 25-50% of ICD recipients, testing cannot be identified as either critical or contraindicated.

Sedation with midazolam for electrical cardioversion

BACKGROUND

Electrical cardioversion (ECV) usually requires the assistance of the anesthesiology team. To avoid this dependence, previous studies have considered the use of sedation with benzodiazepines administered by cardiologists. We describe our experience with intravenous Midazolam during cardioversion.

METHODS

We performed 280 ECV in 202 patients sedated with intravenous Midazolam, without anesthesiology supervision. In scheduled cardioversions, we tested two protocols of Midazolam administration: a bolus of 3 mg, followed by 2 mg each minute until necessary, and a loading dose of 0.09-0.1 mg/kg. In cardioversions performed during electrophysiology studies or defibrillator implant, Midazolam was administered by small repeated doses during the entire procedure.

RESULTS

Midazolam was effective to obtain adequate sedation in 99% of cases. All patients had amnesia with regards of the cardioversion. A loading dose of Midazolam allowed a shortening of the procedural time without serious adverse events. Intubation or the assistance of an anesthetist was never necessary.

CONCLUSION

Sedation with Midazolam for ECV is effective and well tolerated, with some cautions discussed. A loading dose of Midazolam is well tolerated and further reduces the procedural time.

Target-controlled infusion or manually controlled infusion of propofol in high-risk patients with severely reduced left ventricular function

OBJECTIVE

To compare hemodynamics, time to extubation, and costs of target-controlled infusion (TCI) with manually controlled infusion (MCI) of propofol in high-risk cardiac surgery patients.

DESIGN

Prospective, randomized.

SETTING

Major community university-affiliated hospital.

PARTICIPANTS

Twenty patients undergoing first-time implantation of a cardioverter-defibrillator with severely reduced left ventricular function (left ventricular ejection fraction <30%).

INTERVENTIONS

Anesthesia was performed using remifentanil, 0.2 to 0.3 microg/kg/min, and propofol. Propofol was used as TCI (plasma target concentration, 2 to 3 microg x mL; n = 10) or MCI (2.5 to 3.5 mg/kg/hr; n = 10).

MEASUREMENTS AND MAIN RESULTS

Hemodynamics were measured at 6 data points: T1, before anesthesia; T2, after intubation; T3, after skin incision; T4, after first defibrillation; T5, after third defibrillation; and T6, after extubation. There were no significant hemodynamic differences between the 2 groups. Dobutamine was required to maintain cardiac index >2 L/min/m(2) in significantly more patients of the TCI group than of the MCI group. Mean dose of propofol was higher in the TCI patients (6.0 +/- 1.0 mg/kg/hr) than in the MCI patients (3.0 +/- 0.4 mg/kg/hr) (p < 0.05), whereas doses of remifentanil did not differ. Time to extubation was significantly shorter in the MCI (11.9 +/- 2.4 min) versus the TCI group (15.6 +/- 6.8 min). Costs were significantly lower in MCI patients (34.73 dollars) than in TCI patients (44.76 dollars).

CONCLUSIONS

In patients with severely reduced left ventricular function, TCI and MCI of propofol in combination with remifentanil showed similar hemodynamics. TCI patients needed inotropic support more often than MCI-treated patients. Although extubation time was longer in TCI patients and costs were higher, both anesthesia techniques can be recommended for early extubation after implantation of a cardioverter-defibrillator.

Conscious sedation with intermittent midazolam and fentanyl in electrophysiology procedures

OBJECTIVES

To determine the safety and efficacy of intermittent midazolam and fentanyl conscious sedation for electrophysiology procedures (EP).

BACKGROUND

Intermittent midazolam and fentanyl conscious sedation was administered in 700 consecutive cases (175 radiofrequency ablations, 163 EP studies, 261 pacemakers, and 101 implantable cardioverter-defibrillators) for 471 patients (239 males, 51%) mean age 65 +/- 15 years. The mean dose of midazolam was 0.063 mg/kg/hr and fentanyl was 0.591 microgram/kg/hr.

METHODS

Cardiac rate and rhythm were monitored continuously, while blood pressure and arterial oxygen saturation were noninvasively assessed every 5 minutes. Drugs were administered in aliquots of 0.5 to 2.0 mg of midazolam and 6.25 to 25 micrograms of fentanyl as determined by clinical condition every 15 to 30 minutes.

RESULTS

There were no deaths. In no case was endotracheal intubation required. Mild hypoxemia (SaO2 > 80%, but < 90%) occurred in 17 cases (2.4%) and was easily reversed with verbal stimulation and oropharyngeal repositioning (12 cases, 1.7%), increased F1O2 (3 cases, 0.4%), or intravenous naloxone (2 cases, 0.3%). Reversible hypotension (systolic blood pressure < 90, but > 60 mmHg) occurred in 14 patients (2.0%) and was corrected with intravenous crystalloid bolus or flumazenil (10 cases, 1.4%) or inotrope infusion (4 cases, 0.6%). No patient stay was prolonged due to sedation. Only five patients (0.7%) had any recollection of the procedure, while two (0.3%) were aware of pain. All hypoxemic episodes occurred during the first hour, whereas 43% (6/14) of hypotensive episodes occurred after the first hour.

CONCLUSION

Conscious sedation with intermittent midazolam and fentanyl is safe and efficacious for a broad range of EP procedures.

RETRACTED: Total intravenous anesthesia with remifentanil and propofol for implantation of cardioverter-defibrillators in patients with severely reduced left ventricular function

OBJECTIVE

To determine the cardiocirculatory effects of total intravenous anesthesia (TIVA) using remifentanil and propofol in high-risk cardiac surgical patients.

DESIGN

Prospective study of 20 patients undergoing first-time implantation of a cardioverter-defibrillator (ICD).

SETTING

Major, community, university-affiliated hospital.

PARTICIPANTS AND INTERVENTIONS

In 20 patients with severely reduced left ventricular function (left ventricular ejection fraction <30%) undergoing first-time implantation of an ICD, TIVA using remifentanil and propofol was performed.

MEASUREMENTS AND MAIN RESULTS

Extensive hemodynamic monitoring using a pulmonary artery catheter was performed: (T1) before induction of anesthesia, (T2) after intubation, (T3) after skin incision, (T4) after first defibrillation, and (T5) 10 minutes after extubation. Propofol, 3.0 +/- 0.6 mg/kg/h (range, 1.9 to 4.4 mg/kg/h), and remifentanil, 0.30 +/- 0.05 microg/kg/min (range, 0.21 to 0.40 microg/kg/min), were used. Total costs added up to US $44.60 per patient. Patients could be extubated within 12.5 +/- 4.2 minutes after stopping anesthesia. There were significant decreases in heart rate (HR; from 77 +/- 12 to 57 +/- 10 beats/min [T3]), mean arterial blood pressure (MAP; from 98 +/- 14 to 70 +/- 12 mmHg [T2]), and systemic vascular resistance (from 1,551 +/- 309 to 1,233 +/- 274 dyne x s x cm(-5) [T2]). Cardiac index (CI) slightly decreased only at T3 (from 2.46 +/- 0.42 to 1.92 +/- 0.29 L/min/m2; p = 0.04). The decrease in MAP could easily be treated by volume infusion in most patients (17 patients). Sixty-five percent of the patients needed dobutamine to increase CI to greater than 2.0 L/min/m2 (mean dose, 2.2 +/- 1.8 microg/kg/min). Dobutamine could be stopped before extubation in all patients. No patient needed sustained inotropic or ventilatory support and intensive care therapy could be avoided.

CONCLUSION

TIVA using remifentanil and propofol in patients with severely reduced left ventricular function is safe, well-controllable, and allows early extubation after implantation of an ICD. Because patients without complications did not need a postoperative intensive care stay, costs may be considerably reduced.

Patient discomfort following pectoral defibrillator implantation using conscious sedation

BACKGROUND

The miniaturization of implantable cardioverter defibrillators (ICDs) has made pectoral implantation possible. However, postoperative pain following the procedure has not been systematically studied. The aim of the current study was to prospectively assess patient discomfort and identify factors influencing pain perception during follow-up.

METHODS

Pain related to device implantation was quantified in 21 consecutive patients (age, 61 +/- 11 years; 17 men and 21 women; 16 of 21 had coronary artery disease; left ventricular ejection fraction, 32% +/- 15%) undergoing pectoral ICD implantation with conscious sedation (fentanyl 118 +/- 72 micrograms midazolam 14 +/- 9 mg). Patients completed the Visual Analogue Scale (VAS, 0-100) and the McGill Pain Questionnaire 24 hours and 1 month postoperatively. Regression analysis was used to define clinical and procedure related variables affecting patient discomfort and frequency of postoperative analgesic use.

RESULTS

The mean VAS score was 34 +/- 20 24 hours postoperatively. A single (4.8%) patient described postoperative pain as severe. Pain was reported to be moderate by 10 (47.6%) patients and mild by 10 (47.6%) patients. Intraoperative fentanyl requirement was a predictor of postoperative pain (R = 0.51, P = 0.036), and procedural duration was a strong predictor of postoperative analgesic use (R = 0.75, P < 0.001). Pain at 1 month decreased to a VAS score of 19 +/- 18 (P = 0.002 vs 24 hours) and was rated to be severe, moderate, and mild by 1, 3, and 17 patients, respectively. Late pain was related to a VAS score at 24 hours (R = 0.67, P = 0.004).

CONCLUSIONS

(1) Pectoral ICD implantation using conscious sedation is well tolerated. (2) Postoperative discomfort correlates with longer procedural times and larger intraoperative narcotic requirements.

Electrical cardioversion of atrial fibrillation or flutter with conscious sedation in the age of cost containment

BACKGROUND

The purpose of this study was to compare the safety, efficacy, and cost of conscious sedation administered by electrophysiologists certified in the use of conscious sedation with sedation administered by anesthesiologists during cardioversion of atrial fibrillation or atrial flutter to sinus rhythm.

METHODS AND RESULTS

Patients with hemodynamically stable persistent atrial fibrillation and flutter were included in this study. Group 1 patients (n = 33) were sedated by an anesthesiologist and group 2 patients (n = 26) were sedated by an electrophysiologist. Anesthesiologists used propofol and electrophysiologists used midazolam and morphine for sedation. A cost analysis based on professional charges and cost of medications was performed for both groups and compared. Hospital charges were similar for both groups and were excluded from the cost analysis. Although time to sedation in group 1 was shorter than that in group 2, sedation was adequate in both groups such that no patient in group 1 and only 1 patient in group 2 recalled being shocked. There were no complications in either group. The cost incurred in group 2 was less than that in group 1.

CONCLUSIONS

Sedation administered by electrophysiologists for cardioversion of atrial arrhythmias is safe and cost effective. Midazolam and morphine, the sedative agents administered by electrophysiologists, were effective and well tolerated by patients.

NASPE expert consensus document: use of i.v. (conscious) sedation/analgesia by nonanesthesia personnel in patients undergoing arrhythmia specific diagnostic, therapeutic, and surgical procedures

Use of IV (Conscious) Sedation/Analgesia by Nonanesthesia Personnel in Patients Undergoing Arrhythmia Specific Diagnostic, Therapeutic, and Surgical Procedures. This article is intended to inform practitioners, payers, and other interested parties of the opinion of the North American Society of Pacing and Electrophysiology (NASPE) concerning evolving areas of clinical practice or technologies or both, that are widely available or are new to the practice community. Expert consensus documents are so designated because the evidence base and experience with the technology or clinical practice are not yet sufficiently well developed, or rigorously controlled trials are not yet available that would support a more definitive statement. This article has been endorsed by the American College of Cardiology, October 1997.

Comparison of three different automatic defibrillator implantation approaches: pectoral implantation using conscious sedation reduces procedure times and cost

Recent technological advances in implantable defibrillator systems (ICD) have changed implantation approaches. The aim of this study was to investigate the influence of these improvements on procedure times, implant-related charges, patient recovery, and morbidity. Ninety-six consecutive patients undergoing implantation of a nonthoracotomy ICD were studied. Implantation was performed under general anesthesia with the generator placed abdominally in 22 patients (group I) and pectorally in 40 patients (group II). Thirty-four patients underwent pectoral implantation using conscious sedation (group III). Groups were comparable with respect to clinical variables. Implantation duration and total procedure duration were shorter in group III (67 +/- 21 minutes and 117 +/- 30 minutes) when compared with group I (100 +/- 25 minutes and 157 +/- 39 minutes) and group II (86 +/- 24 minutes and 153 +/- 34 minutes, P < 0.05). Patients in group III did not require admission to the Post-Anesthesia Care Unit. In contrast, patients in groups I and II spent 92 +/- 28 minutes and 91 +/- 31 minutes in the Post-Anesthesia Care Unit. Implantation-related charges were reduced in patients having pectoral implantation using conscious sedation ($1451 +/- 217 vs. $2354 +/- 550 and $2796 +/- 384, P < 0.05). Patients in group III had a lower frequency of postoperative oral analgesic use (3.2 +/- 2.7 doses, P < 0.05) and a shortened post-operative length of stay (1.9 +/- 1.6 days, P < 0.05) when compared with groups I (5.7 +/- 4.0 doses and 3.3 +/- 1.4 days) and II (5.2 +/- 3.5 doses and 2.6 +/- 1.1 days). The overall complication rate was low (6.3%), with no differences between groups. Advances in ICD technology have simplified implantation, leading to shorter, less painful, and less expensive procedures.

Conscious sedation with combined hypnotic agents for implantation of implantable cardioverter-defibrillators

OBJECTIVES

The objective of this study was to evaluate the feasibility, safety and efficacy of placing implantable cardioverter-defibrillators (ICDs) in the electrophysiology laboratory using conscious sedation with combined hypnotic agents and deep sedation with etomidate.

BACKGROUND

Implantable cardioverter-defibrillators with transvenous leads permit the use of simplified implantation techniques similar to those used for the insertion of permanent pacemakers. However, implantation of ICDs without general anesthesia has thus far gained limited acceptance.

METHODS

In 162 patients, conscious sedation during ICD placement was achieved with combined intravenous midazolam, morphine and promethazine (Phenergan). Intravenous etomidate was administered to induce deep sedation for defibrillation threshold testing. First-time implantations were in the prepectoral position (n = 142), but some patients with preexisting devices received abdominal implants (n = 20). The results were compared with those of concurrent patients (n = 56) who received prepectoral implants under propofol anesthesia administered by an attending anesthesiologist.

RESULTS

The anesthetic protocol was implemented without major intraoperative complications. During deep sedation with etomidate, episodes of apnea, hypoxia or arterial hypotension requiring therapeutic intervention did not occur. During a mean (+/-SD) follow-up period of 257 +/- 140 days (median 227, range 14 to 482), there were, among the 162 patients, a total of two nonsudden cardiac deaths-one 71 days and the other 157 days after the operation. There were two nonsudden deaths in the concurrent control subjects (n = 56)-one 13 days and the other 110 days after the operation.

CONCLUSIONS

Implantation of ICDs under conscious sedation with combined hypnotic agents and deep sedation with etomidate is a safe and effective procedure with low perioperative morbidity and low long-term complication rates.