Modern medicine, primarily concerned with clinical outcomes of medical management, is becoming increasingly aware of economic-organizational aspects. This seems unavoidable due to sustained advances in medical sciences, continuously improved diagnostic and therapeutic methods, and hence constantly and quickly growing needs for funds.

In the field of anaesthesiology, the number of agents markedly increases thanks to continuous pharmacological progress. A high proportion of them are expensive. However, in many cases the use of more expensive drugs enables the attainment of savings, which ultimately outweigh the expenditure. Moreover, new techniques of anaesthesia are continuously and quickly developed, which favours better management outcomes and lower procedure-related costs. In the anaesthesiological literature, only a few percent of papers provide any information about costs [1].

The aim of the present study was to compare hospital costs of general versus subarachnoid anaesthesia for Caesarean section.

METHODS

Costs were assessed from the perspective of a service provider. Total direct costs of anaesthesia were calculated (Fig.1). Additionally, the number of hospitalization days of patients undergoing general vs subarachnoid anaesthesia was compared.

General anaesthesia was induced with atropine (Atropinum sulfuricum, Polfa Warsaw, PL), thiopentone (Thiopental, Sandoz, Austria) and suxamethonium (Chlorsuccillin, Jelfa, PL) and maintained with N20-60%, O2-30% (Linde Gaz, PL), fentanyl (Fentanyl, Polfa Warsaw, PL) and, in some cases cis-atracurium (Nimbex, Glaxo Wellcome, GB). The flow of fresh gases was
6 L min-1.  In some cases, in which deeper anaesthesia was necessary, sevoflurane (Sevorane, Abbott, GB) was administered. It was assumed that 0.79 mL of sevoflurane is consumed during one minute of anaesthesia [2]. The neuromuscular block was reversed, if necessary, with neostigmine (Polstygminum, Pliva, PL). Endotracheal intubation was performed to maintain the airways.

Subarachnoid anaesthesia was carried out using 0.5% hyperbaric bupivacaine (Marcaine Spinal Heavy 0.5%, Astra Zeneca, Sweden) or 0.5% isobaric bupivacaine  (Bupivacainum hydrochloricum, Polfa Warsaw, PL) with 2% lignocaine (Lignocainum hydrochloricum 2%, Polfa Warsaw, PL) to anaesthetize the skin. The 25, 26 and 27G spinal needles were applied.

During anaesthesia, patients were routinely monitored using ECG, non-invasive blood pressure measurements and pulse oximetry.

The direct medical costs were measured using the micro-cost method based on detailed data of the resources used during anaesthetic procedures. The costs of anaesthetic agents, drugs and medical gases were calculated based on the dispensary drug prices. The costs of equipment, disposable materials and disinfectants were calculated according to the manufacturers’ prices.

Evaluating the direct costs of anaesthesia, materials associated with the anaesthetic technique were distinguished and their costs estimated.

The materials associated with the technique of general anaesthesia included thiopentone, suxamethonium, cis-atracurium neostigmine, N2O, sevoflurane, lignocaine in aerosol, neomycin (eye ointment) and endotracheal tubes.

The materials related to the technique of subarachnoid anaesthesia included 0.5% hyperbaric bupivacaine, 2% lignocaine, ephedrine (Ephedrinum hydrochloricum, Polfa Warsaw, PL), sets for subarachnoid anaesthesia, needles for subarachnoid anaesthesia, sterile gloves, and the skin disinfectant – dodesept (Prevacare, Arcana, Austria).

The unit costs of hospitalization were determined using the “top-to-bottom” calculation [3]. According to this method, the personnel work-related costs in the Department of Obstetrics, the costs of medical materials used and the yearly number of persondays were used to calculate the costs of one personday. The suitable financial-administrative data were obtained from the service provider. In the analysis, the mean costs of hospitalization during the study period – 296.5 zł – were used.

The non-medical costs were calculated by the direct allocation method, i.e. the costs of auxiliary units (laundry, boiler house, incinerator, cleaning services, Occupational Medicine Clinic) are allocated to the units providing direct services – the Department of Anaesthesiology. The financial-administrative data were obtained from the service provider.

The costs of multiple use equipment, its depreciation and sterilization were assessed using the macro-cost method. For this purpose, the operating costs of the Department of Anaesthesiology and Intensive Therapy were used.  The service provider delivered the suitable financial-administrative data.

The costs related to anaesthesiological staff work were calculated by the micro-cost method based on the duration of anaesthesia (the time between the patient`s arrival in and leaving the operating room). The mean gross base remuneration of physicians and nurses of the Department of Anaesthesiology, duties included, was used (with Social Insurance contributions paid by the employer).

The remaining elements of personnel costs were calculated based on the total operating costs of the Department of Anaesthesiology; the data needed were obtained from the service provider.

To estimate the remaining operating costs of the Department of Anaesthesiology per one anaesthesia, the operating costs of the Department in question were analysed. The non-medical costs analysed included costs of laundry, cleaning, heating and electrical energy, water supply, sewage disposal, costs of materials for renovation and maintenance of medical and office devices, postal, telephone and transport services, costs of protective clothes, bed linen and materials for repair and maintenance of equipment.  The medical costs analysed involved: costs of multiple use medical equipment (with depreciation), costs of sick-leave remuneration, retirement gratuity, fee-for-task agreements, contracts for specific tasks, allowances (management, seniority, overtime, related to increases in earnings), costs of personnel trainings, benefits for employees, contributions for the National Disabled Persons  Rehabilitation Fund and social fund.

According to the recommendations for pharmacoeconomic studies, the analysis of sensitivity to personnel remuneration in case of its hypothetic changes by 50%, 100% and 150% as well as changes in prices of pharmaceutical preparations and disposable materials by 15% was performed. Moreover, the best and the worst scenarios were considered.

The results were analysed statistically. The Student’s t-, Cochran-Cox and F tests were used. The level of significance was set at p=0.05.

RESULTS

The study was carried out in the I Department of Anaesthesiology and Intensive Therapy, Medical University of Lublin in 2007. The collected data concerned 261 general and 151 subarachnoid anaesthetic procedures.

The direst costs of anaesthesia for Caesarean section were significantly lower for general anaesthesia (Table 1). The mean cost related to work of anaesthesiological personnel was significantly higher in cases of subarachnoid anaesthesia compared to general anaesthesia.  However, the share of work-related costs (personnel costs) in the total costs of anaesthesia was higher for general than subarachnoid anaesthesia as the duration of anaesthesia was substantially longer in the group of subarachnoid procedures (Table 1).

The non-personnel costs of subarachnoid anaesthesia were higher than of general anaesthesia (Table 1), which resulted from significantly lower costs of anaesthetic drugs for subarachnoid procedures. Likewise, the percentage share of costs of anaesthetic agents in the direst costs of anaesthesia was lower for subarachnoid anaesthesia compared to general anaesthesia. The highest non-personnel costs were noted in anaesthesias with sevoflurane (Fig. 2).

The highest non-personnel costs of subarachnoid anaesthesia were found in the group of patients anaesthetized with hyperbaric bupivacaine and undergoing colloid fluid transfusions (Voluven, Fresenius-Kabi, PL). The lowest costs were observed in patients receiving isobaric bupivacaine (Fig. 3).

The costs of disposable materials were considerably higher for subarachnoid than general anaesthesia, which resulted from higher percentage share of disposable materials in the direct costs of subarachnoid (35.03%) compared to general anaesthesia (24.09%) (Table 1).

The mean technique-related costs were significantly higher for subarachnoid anaesthesia (Table 1).

The operating costs of the Department of Anaesthesiology, not included in the direct costs, calculated for one anaesthesia were 103.7 zł. Hence, the total direct costs of anaesthesia for Caesarean section were increased by this amount. 

The sensitivity analysis for anaesthesiological personnel salaries expected to increase (Table 2) and for pharmaceutical preparations, disposable materials and disinfectants was carried out. Assuming their price increase by 15% (the worst scenario), the direct costs of general anaesthesia should increase by 7.87% reaching 188.03 zł, and the direct costs of subarachnoid anaesthesia by 8.45% - reaching 239.69 zł.

DISCUSSION

The studies showed that the costs of general anaesthesia for Caesarean section were relatively low in comparison with its use for other surgical procedures as sevoflurane was used only in few cases. Sevoflurane, as an element of anaesthesia, increased the direct costs of anaesthesia even by 360 zł (the total direct costs reaching then about 463 zł).

Sevoflurane is an expensive anaesthetic. According to Gaszyński and Machała [6], in 2005 the costs of one-hour anaesthesia with this agent (without personnel work costs) was 180.56 zł. In the same study, the costs of infusion induction with sevoflurane were estimated at 137.05 zł, and one-hour anaesthesia maintenance at 63.58 zł. When our study was carried out, the National Health Fund assessed the anaesthetic procedure <1h at 300 zł and that >1h at 400 zł. These costs may be underestimated in procedures other than Caesarean sections. The type of surgery the anaesthesia is provided for is the factor affecting the costs of anaesthesia [7].

Our study indicated that subarachnoid anaesthesia for Caesarean section was more expensive than general anaesthesia. This finding differs from the results of other studies. Schuster and colleagues [8] demonstrated economic superiority of subarachnoid anaesthesia compared to general anaesthesia. However, anaesthetic procedures described by them concerned various surgeries (hernia, hand injury, hysterectomy, arthroscopy and several Caesarean sections) and the agents used (sevoflurane, desflurane, isoflurane, remifentanil, propofol or etomidate) definitely increased the costs of general anaesthesia.

The same authors found that the personnel costs constituted 78% of total anaesthesia-related costs whereas in our study – 50%. However, the authors did not provide methodological details of their study, thus it should be assumed that the difference results from higher salaries of medical staff in Germany where in 2005 the average monthly salary of an anaesthesiologist was 6600 €, and of an anaesthesiological nurse – about 4400 € [8].

According to the Canadian study, the personnel costs constitute 81% of perioperative costs of anaesthesia for upper limb surgery, the remaining costs are related to pharmacological agents and disposable materials [9].

In the study performed by Gonano and co-workers [7], subarachnoid anaesthesia appeared to be cheaper. The costs of agents used during general anaesthesia with volatile anaesthetics was 51.5 €, of disposable materials – 34.5 € on average, which, accounting for the exchange rate at that time, corresponded to 200.33 zł and 134.2 zł [10]. Higher costs of pharmaceuticals, compared to our findings, resulted from the use of more expensive anaesthetics – sevoflurane, propofol and rocuronium. The costs of disposable materials in the study mentioned were only slightly higher than the costs of these materials found in our study. Moreover, the duration of anaesthesia was also relevant for cost-effectiveness of anaesthesia – longer duration in the study referred to. 

The wide-range pharmacoecomonic analysis comparing various methods of anaesthesia for hernia repair did not demonstrate significant differences in total hospital costs for regional and general anaesthesia [11]. This is confirmed by our study in which the time of hospitalization (hence its costs) in both groups of patients was comparable.

Any analysis of anaesthesia costs should be considered with caution as structures of costs may differ in various centres [12]. Our study was carried out in the teaching hospital of the highest referral level. Therefore, a high proportion of patients with high-risk pregnancy are treated there, whose hospitalization is potentially more expensive. The factors mentioned affect also the number, type and costs of anaesthesias performed in the hospital.

CONCLUSIONS

1. Total direct costs of subarachnoid anaesthesia for Caesarean section are higher than of general anaesthesia.

2. The share of costs of technique-related materials is higher for subarachnoid than general anaesthesia.

3. Subarachnoid anaesthesia lasts longer than general anaesthesia, which increases personnel work-related costs.

4. Total direct costs of general anaesthesia for Caesarean section are lower when volatile halogenated anaesthetics are not used.

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REFERENCES

1.    Niewada M, Jastrzębski JA: Analiza farmakoekonomiczna w nowoczesnej praktyce anestezjologicznej. Przewodnik Menedżera Zdrowia 2001; 3: 40-46.

2.    Materiały Naukowo-Szkoleniowe Ogólnopolskiej Konferencji “Znieczulenie Wziewne”, Kazimierz Dolny 2004.

3.    Orlewska E, Nowakowska E: Farmakoekonomika dla studentów i absolwentów Akademii Medycznych. Wydawnictwo AM. Poznań 2004.

4.    Drummond MF, O’brien B, Stoddart GL, Torrance GW: Methods for the economic evaluation of health care programs Oxford University Press, New York, 1997.

5.    Orlewska E, Mierzejewski P: Polskie wytyczne przeprowadzania badań farmakoekonomicznych (projekt). Farmakoekonomika 2000; 1: 3-11.

6.    Gaszyński W, Machała W: Analiza kosztów znieczulenia ogólnego. Med-info 2006; 7: 37-40.

7.    Gonano C, Leitgeb U, Sitzwohl C, Ihra G, Weinstabl C, Kettner SC: Spinal versus general anesthesia for orthopedic surgery: anesthesia drug and supply costs. Anesth Analg 2006; 102: 524-529.

8.    Schuster M, Gottschalk A, Berger J, Standl T: A retrospective comparison of costs for regional and general anesthesia techniques. Anesth Analg 2005; 100: 786-794.

9.    Chan VWS, Peng PWH, Kaszas Z, Middleton W, Muni R, Anastakis DG, Graham BA: A comparative study of general anesthesia, intravenous regional anesthesia and auxiliary block of outpatient hand surgery: clinical outcome and cost analysis. Anesth Analg 2001; 93: 1181-1184.

10.    Kursy walut NBP. Tabele archiwalne. www.money.pl

11.    Nordin P, Zetterström H, Carlsson P, Nilsson E: Cost-effectiveness analysis of local, regional and general anesthesia for inguinal hernia repair using data from a randomized clinical trial. Br J of Surgery 2007; 94: 500-505.

12.    Ruciński P: Kliniczne i ekonomiczne aspekty leczenia arytmii przedsionkowych przy pomocy stałej stymulacji serca. Rozprawa doktorska, AM w Lublinie, 2005.

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Address:

*Magdalena Kwiatosz-Muc
I Klinika Anestezjologii i Intensywnej Terapii UM
SPSK NR 4, ul. Jaczewskiego 8, 20-090 Lublin
tel.: 81-724 43 32, fax: 81-724 45 50
e-mail: anest@am.lublin.pl

Received: 06. 01. 2010
Accepted: 20. 04. 2010