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Local anesthesia versus general anesthesia for cardioverter/defibrillator implantation |
Stix G, Anvari A, Pernerstorfer T, Grimm M, Turel Z, Mayer C, Laufer G, Schmidinger H |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. Health technology The use of local versus general anaesthesia for cardioverter/defibrillator implantation.
Economic study type Cost-effectiveness analysis.
Study population The study population comprised patients undergoing implantation of a single-lead unipolar transvenous ICD-system.
Setting The setting was hospital. The economic analysis was carried out in Austria.
Dates to which data relate The dates of the effectiveness, resource use and cost data were not reported. The price year was also not reported.
Source of effectiveness data The effectiveness data were derived from a single study.
Link between effectiveness and cost data The costing was carried out prospectively on the same patient sample as that used in the effectiveness analysis.
Study sample The ICD was implanted in 40 consecutive patients: 20 under GA and 20 under LA. No power calculations were reported. The mean age of the patients was 59 years, and there were 29 men and 11 women. Ischaemic heart disease was present in 27 patients, of which 25 had had a previous remote transmural myocardial infarction. Eleven patients had idiopathic-dilated cardiomyopathy, and 2 patients non-obstructive hypertrophic cardiomyopathy. Fourteen patients presented with ventricular fibrillation, and 25 with monomorphic ventricular tachycardia; one young patient with hypertrophic non-obstructive cardiomyopathy and episodes of syncope gave a family history of sudden cardiac death, so the device was implanted prophylactically. Twenty-five patients had a history of cardiopulmonary resuscitation.
Study design This was a prospective cohort study carried out at a single centre. The patients were followed-up until discharge, and there were no patients lost to follow-up.
Analysis of effectiveness The analysis was based on intention to treat. The primary health outcomes were DFT, the patient's acceptance of the procedure, cardiorespiratory function throughout the procedure, and complications. There were no significant differences between the two groups in terms of age, body weight, underlying disease, left ventricular ejection fraction, and classification according to the New York Heart Association.
Effectiveness results The variables were expressed as the mean plus or minus the standard deviation (SD). DFT was 13.7 (SD=5.5) joules (J) under LA and 10.7 (SD=4.7) J under GA. Under LA, all 20 patients achieved a sufficient DFT (24 J), whereas under GA, the unipolar system was ineffective for 2 of the 20 patients and a bipolar device had to be implanted. For DFT testing, 7.5 (SD=2.8) shocks had to be applied to patients under GA, compared with 6.2 (SD=1.3) shocks under LA. Mean heart rate, arterial oxygen saturation, and mean arterial blood-pressure remained stable throughout DFT testing, irrespective of the type of anaesthesia used. There were no complications in either group and the procedure was well tolerated.
Clinical conclusions LA in combination with mild sedation is as safe and well tolerated as GA in ICD implantation. The use of lidocaine for LA does not adversely affect DFT. Device implantation in a pacemaker-like approach results in a significant reduction in total procedure time, and will provide the patients with easier procedure scheduling.
Measure of benefits used in the economic analysis The measures of benefit were DFT, the patient's acceptance of the procedure, cardiorespiratory function throughout the procedure, the duration of the implantation procedure, and complications. Hence, this study constituted a cost-consequences analysis.
Direct costs The direct costs were not discounted due to the short timeframe (less than 1 year) of the study. The quantities and costs were not reported separately, except for the duration of the implantation procedure. No prices were given. The direct costs related to the costs of anaesthesia. The quantity/cost boundary adopted was that of the hospital. The cost data were derived from the authors' institution. The price year was not reported. The duration of the surgical procedure was 62 (SD=16) minutes under GA and 60 (SD=14) minutes under LA. The entire implantation procedure was significantly longer in patients under GA than in patients under LA: 124 (SD=24) versus 97 (SD=22) minutes (p<0.005).
Statistical analysis of costs The Mann-Whitney U-test was used to compare parameters between the two groups.
Indirect Costs Indirect costs were not included.
Sensitivity analysis No sensitivity analyses were conducted.
Estimated benefits used in the economic analysis See the effectiveness results reported above.
Cost results The total costs amounted to $470 for GA and $130 for LA with mild sedation.
Synthesis of costs and benefits Authors' conclusions LA in combination with mild sedation is as safe and well tolerated as GA in ICD implantation. Lidocaine used for LA does not adversely affect DFT. Device implantation in a pacemaker-like approach results in a significant reduction in total procedure time and costs, and will provide the patients with easier procedure scheduling.
CRD COMMENTARY - Selection of comparators A justification was given for the comparator used, namely that it was a current treatment alternative. You, as a user of the database, should decide if these health technologies are relevant to your setting.
Validity of estimate of measure of effectiveness The analysis was based on a prospective cohort study, which was appropriate for the study question. The authors reported baseline patient characteristics, which can be used by decision-makers to assess the generalisability of the results. The analysis of effectiveness was handled credibly.
Validity of estimate of measure of benefit The estimation of benefits was obtained directly from the effectiveness analysis.
Validity of estimate of costs More details could have been provided about the costs associated with anaesthesia. The cost estimates were derived from the authors' institution, and may not be generalisable to other settings. The price year was not reported, which makes reflation exercises difficult. The quantities and costs were not reported separately, except for the duration of the implantation procedure. No prices were given. No sensitivity analyses were conducted on costs.
Other issues The authors made appropriate comparisons of their findings with those from other studies, but did not address the issue of generalisability to other settings. The authors did not present their results selectively. The study considered patients undergoing implantation of a single-lead unipolar transvenous ICD-system and this was reflected in the authors' conclusions. The dates of the effectiveness, resource use, and cost data were not reported. The study may have suffered from a sample size that was too small to detect statistically-significant differences between the two groups.
Implications of the study The authors claimed that ICD implantation may routinely be performed under LA with a reduced number of staff, thus providing further reduction in overall costs. However, the small sample size and the lack of detail on the costing procedure restrict the validity and generalisability of these conclusions.
Bibliographic details Stix G, Anvari A, Pernerstorfer T, Grimm M, Turel Z, Mayer C, Laufer G, Schmidinger H. Local anesthesia versus general anesthesia for cardioverter/defibrillator implantation. Heartweb 1997; 2(3): U43-U48 Indexing Status Subject indexing assigned by NLM MeSH Anesthesia, General /methods /economics; Anesthesia, Local /methods /economics; Cardiac Surgical Procedures /trends /economics /methods; Comparative Study; Defibrillators, Implantable /economics; Female; Humans; Male; Middle Aged; Premedication /economics /methods /trends AccessionNumber 21997001145 Date bibliographic record published 28/02/2002 Date abstract record published 28/02/2002 |
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