Journal of Clinical Neuroscience xxx (2015) xxx–xxx
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical Study
General versus epidural anesthesia for lumbar microdiscectomy Murat Ulutas a,⇑, Mehmet Secer b, Ozgur Taskapilioglu c, Soner Karadas d, Ahmet Aykut Akyilmaz d, Yunus Baydilek d, Betul Kocamer d, Ayse Ozboz d, Suat Boyaci e a
Department of Neurosurgery, Sanko University, Konukoglu Hospital, Ali Fuat Cebesoy Bulvari, Sßehitkamil 7090, Gaziantep, Turkey Department of Neurosurgery, Deva Hospital, Gaziantep, Turkey c Department of Neurosurgery, Uludag University Medical Faculty, Bursa, Turkey d Department of Anaesthesiology, Sanko University, Konukoglu Hospital, Gaziantep, Turkey e Department of Neurosurgery, Acibadem Hospital, Bursa, Turkey b
a r t i c l e
i n f o
Article history: Received 6 December 2014 Accepted 4 February 2015 Available online xxxx Keywords: Cost Epidural anesthesia General Lumbar microdiscectomy
a b s t r a c t This study was a retrospective analysis of 850 lumbar microdiscectomy (LMD) under epidural anesthesia (EA; n = 573) or general anesthesia (GA; n = 277) performed by the same surgeon and paid by invoice to the Social Security Institution of the Turkish Republic between April 2003 and May 2013. Although GA is the most frequently used method of anesthesia during LMD, the choice of regional anesthetia (epidural, spinal or a combination of these) differs between surgeons and anesthetists. Studies have reported that EA in surgery for lumbar disc herniation may be more reliable than GA, as it enables the surgeon to communicate with the patient during surgery, but few studies have compared the costs of these two anesthetic methods in LMD. We found that EA patient costs were significantly lower than GA patient costs (p < 0.01) and there was a statistically significant difference between the two groups in terms of the time spent in the operating room (p < 0.01). There was no difference in the duration of surgery (p > 0.05). The anesthetic method used during LMD affected the complication rate, cost and efficiency of operating room use. We suggest that EA is an anesthetic method that can contribute to health care cost savings and enable LMD to be completed with less nerve root manipulation and more comfort, efficacy, reliability and cost efficiency without affecting the success rate of the surgical procedure. Ó 2015 Elsevier Ltd. All rights reserved.
1. Introduction Symptoms related to lumbar disc herniation reduce the quality of everyday life and cause a loss of labor force productivity, and lumbar disc hernia surgery is one of the most frequently performed surgical procedures in neurosurgical practice. Surgical techniques for the treatment of lumbar disc herniation, such as microdiscectomy and endoscopic approaches, have been developed to reduce the duration of hospitalization and to allow a rapid return to daily life and work. In addition, the type of anesthesia used is important for reducing complications during and after surgery and can affect patient comfort. Although general anesthesia (GA) is the most frequently used method during lumbar microdiscectomy (LMD), the choice of a regional anesthetic (epidural, spinal or a combination of these) differs between surgeons and for different anesthetics. Studies have reported that epidural anesthesia (EA) in LMD may be more reliable than GA as it allows the surgeon to ⇑ Corresponding author. Tel.: +90 533 515 05 48; fax: +90 342 2115010. E-mail address: [email protected] (M. Ulutas).
communicate with the patient during surgery, but few studies have compared the costs of these two anesthetic methods in LMD surgery [1,2]. In general, the annual cost of minimally invasive approaches for LMD surgery has increased in parallel with the use of modern technology. When the cost of anesthesia is considered, the use of the most economical anesthetic method can significantly reduce the total cost of LMD surgery. For other surgical procedures, the costs of regional anesthetic and GA methods have been compared and it has been found that the cost of anesthesia is mainly related to its effect on surgical duration and whether the surgery can occur in an ambulatory setting [3– 5]. This retrospective investigation compared the length of time the operating room was occupied and the cost of anesthesia when EA and GA methods were used, and assessed EA reliability and applicability. Complications linked to patient position during GA (peripheral nerve compression, ophthalmological damage), complications linked to EA (unsuccessful EA, epilepsy) and general surgical complications (dural injury, infection, additional neurological deficits) were also examined and discussed with regard to the anesthetic method used.
http://dx.doi.org/10.1016/j.jocn.2015.02.018 0967-5868/Ó 2015 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Ulutas M et al. General versus epidural anesthesia for lumbar microdiscectomy. J Clin Neurosci (2015), http://dx.doi.org/ 10.1016/j.jocn.2015.02.018
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M. Ulutas et al. / Journal of Clinical Neuroscience xxx (2015) xxx–xxx
2. Methods Permission was granted by the Gaziantep Sanko University Sani Konukoglu Private Hospital Ethics Committee prior to retrospectively screening a total of 850 LMD under EA (n = 573) or GA (n = 277) performed by the same surgeon and financed by invoice to the Social Security Institution of the Turkish Republic between April 2003 and May 2013. All patients provided written consent for the surgical procedure and anesthetic method. Patients with radicular pain and/or neurological deficits linked to disc compression, as identified by imaging (MRI and CT scan), and who had no response to at least 3 weeks of conservative treatment, underwent a standard LMD with a surgical microscope (Leica M525 OH4; Leica Biosystems, Nussloch, Germany). Patients were recorded for age, sex, operated disc levels, duration in the operating room, duration of surgery, the patient’s first request for postoperative analgesia, the cost of anesthesia and complications. The duration in the operating room and the duration of surgery were obtained from the anesthesia monitoring form, and the EA and GA patients were compared based on these parameters. In the postoperative period, the time of the first analgesic request by the patient was obtained from the observation chart. 2.1. Anesthesia procedure All patients were given 1 mg of intravenous midazolam 30 minutes before the operation as a premedication. Additionally, antibiotic prophylaxis was given using 1 g of cefazolin before skin incision and 1 g every 8 hours postoperatively. Before induction in the GA group, 4 L/minute oxygen (O2) was given through a mask for preoxygenation. Induction was then conducted using 1 lg/kg remifentanil, 2–3 mg/kg propofol and 0.5 mg/kg rocuronium intravenously. After induction and oxygenation, intubation was performed with an endotracheal tube with a cuff. To maintain anesthesia, 0.25 lg/kg remifentanil, 2–2.5% sevoflurane and 4 L/minute fresh gas flow (50% O2/50% air mix) were administered. Before extubation, 1 ampule of a nonsteroidal anti-inflammatory drug (NSAID) and 0.5 mg/kg tramadol were administered. After approximately 30 minutes in the recovery room, the patient was sent to the ward. In the operating room, EA was administered in the sitting position under aseptic conditions at one or two levels above the operation field. After local anesthesia with subcutaneous prilocaine hydrochloride, an 18 gauge Tuohy needle was inserted into the epidural space using the loss of resistance method and a 14– 16 cm3 mix of 50 lg fentanyl (1 cm3), 100 mg lidocaine hydrochloride (5 cm3) and 50 mg bupivacaine (10 cm3) was administered. An epidural catheter was not inserted in any patients. After the injection, the patients were laid in a horizontal position. Following this, the surgical region and legs were checked for pain sensation using the pinprick test after which the patients were placed in the prone position. After the patients were settled in the most comfortable and appropriate prone position, they were sedated using 0.03 mg/kg midazolam. After 10 minutes in the recovery room in the postoperative period, they were moved to the ward. 2.2. Cost To calculate the direct costs for each patient, the intravenous and ıntramuscular medications used for anesthesia and the volatile anesthetics, single-use supplies, preoperative and postoperative analgesics and other medications used were considered. The time expenditure costs of personnel, surgeon and anesthetist fees, general costs of running the hospital such as electricity, water, air
conditioning and depreciation, and the aspects of LMD that were the same for both anesthetic methods such as surgical procedure medication, supplies and preoperative preparation (laboratory and radiology), were not included in the calculation. Because all ampules and vials were destroyed regardless of their remaining contents in accordance with the Turkish Ministry of Health’s Implementation Communiqué, the cost calculation for the ampules and vials was based on the numbers used. The data used for the cost calculation for each patient were obtained from the invoice information in the hospital computer system, which included the prices of anesthetic medications, supplies and postoperative analgesic medications. The prices of the medications used for anesthesia in the operations under EA or GA and the prices for postoperative analgesia were collected separately. The average cost was obtained in Turkish Liras (TL) and converted into US dollars (1 USD: 2.1 TL). The cost calculation for GA was performed based on the total price of anesthetic medications, intravenous fluids, postoperative analgesic medications (NSAID, tramadol) and supplies (intubation tubes, aspiration probes, intravenous catheters, injectors, disposable anesthetic breathing circuit devices, airway tubes). The costs of the medications used to treat side effects in the postoperative period such as nausea, vomiting, hypotension and bronchospasm were also added to the cost calculation. The cost calculation for EA included the costs of anesthetic medications (crystalloid, bupivacaine, prilocaine hydrochloride, fentanyl, lidocaine hydrochloride, midazolam), supplies (intravenous catheters, Tuohy needles, injectors) and postoperative analgesic medications (NSAID, tramadol). 2.3. Statistical analyses SPSS statistics (version 21; IBM Corporation, Armonk, NY, USA) was used for the statistical analyses. Descriptive statistics for continuous variables are given as the mean ± standard deviation and median (range) values. Comparisons between the groups were completed with Mann–Whitney tests and independent sample t-tests for continuous variables, and chi-squared tests for categorical variables. A correlation analysis was also completed. Statistical significance was accepted at p < 0.05.
3. Results A total of 850 LMD were completed in 797 patients (53 patients underwent repeat LMD due to recurrence at the same level); 573 surgeries were performed under EA and 277 were performed under GA. There was no significant difference between the EA and GA patients in terms of age or sex (p > 0.05; Table 1). Thirty-four of the operations performed under EA and 39 under GA were second operations performed for recurrence at the same level as that treated by the original surgery; 28 and 25 of those patients had undergone the original surgery at our clinic and 6 and 14 at other centers, for the EA and GA groups, respectively (Table 2).
Table 1 Demographic distribution of lumbar microdiscectomy patients by type of anaesthesia
Epidural anesthesia General anesthesia
LMD, n
Age, mean years ± SD
Age range, years*
Sex (M/F)*
573 277
44.2 ± 11.86 43.33 ± 11.18
20–76 20–70
328/245 158/119
* EA versus GA patients for age and sex (p > 0.05). F = female, LMD = lumbar microdiscectomy, M = male, SD = standard deviation.
Please cite this article in press as: Ulutas M et al. General versus epidural anesthesia for lumbar microdiscectomy. J Clin Neurosci (2015), http://dx.doi.org/ 10.1016/j.jocn.2015.02.018
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M. Ulutas et al. / Journal of Clinical Neuroscience xxx (2015) xxx–xxx Table 2 Level, side and recurrence of lumbar microdiscectomy in 850 patients n = 850
Level
Epidural anesthesia (573) n (%)
Level
General anesthesia (277) n (%)
One level, n = 705, 82.9%
L5–S1 L4–5 L3–4 L2–3 Total
209 (36.4) 264 (46.07) 27 (4.7) 1 (0.17) 501 (87.4)
Two levels, n = 55, 6.5%
L4–5, L5–S1 L3–4, L4–5 L3–4, L5–S1 Total L5–S1 L4–5 Total L5–S1 L4–5 L3–4 Total
16 (2.79) 8 (1.39) 1 (0.17) 25 (4.36) 4 (0.69) 9 (1.57) 13 (2.26) 17 (2.96) 14 (2.44) 3 (0.52) 34 (5.93)
L5–S1 L4–5 L3–4 L2–3 L1–2 Total L4–5, L5–S1 L3–4, L4–5 T12–L1, L5–S1 Total L4–5 L2–3 Total L5–S1 L4–5 L3–4 Total
82 (29.6) 107 (38.62) 10 (3.61) 3 (1.08) 2 (0.72) 204 (73.64) 15 (5.41) 14 (5.05) 1 (0.36) 30 (10.8) 3 (1.08) 1 (0.36) 4 (1.46) 13 (4.69) 24 (8.79) 2 (0.72) 39 (14.77)
Bilateral, n = 17, 2%
Recurrence, n = 73*, 8.6%
*
For 20 patients, the first operation was performed at a different hospital by an other surgeon, and for 53 patients the first operation was at our clinic.
Table 3 Average cost, duration of operating room occupation and duration of operation in lumbar microdiscectomy patients by type of anesthesia
General anesthesia Epidural anesthesia
Cost*, mean USD ± SD (range)
Duration of occupation of operating room*, mean minutes ± SD (range)
Duration of operation, mean minutes ± SD (range)
54.46 ± 21.81*** (22–131) 30.89 ± 11.88 (16–76)
107.6 ± 25.83*** (30–180) 81.84 ± 21.48 (30–180)
72.91 ± 21.35** (30–165) 67.7 ± 19.6** (20–155)
*
Time spent in the operating room versus the average cost for GA and EA groups, p < 0.01. Duration of operation (GA) versus duration of operation (EA) p > 0.05. *** Positive linear relationship between time spent in the operating room and the average cost for GA patients, p = 0.668. EA = epidural anesthesia, GA = general anesthesia, SD = standard deviation, USD = United States dollars. **
EA costs were significantly lower than GA costs (p < 0.01; Table 3). At hospitals that operate under an agreement with the Turkish Social Security Institution, a fixed compensation rate of 571.42 USD is paid for LMD surgery. Of this income, the portion used for medication supplies and analgesics is 5.4% for LMD surgeries performed under EA and 9.53% for those performed under GA. Thus, the EA group used 43.28% less funds than the GA group. While there was a statistically significant difference between the two groups in terms of time spent in the operating room (p < 0.01), there was no difference in the duration of surgery (p > 0.05). There was also a strong positive linear correlation between the time spent in the operating room and total cost (Table 3). Due to severe compression of the nerve root caused by subligamentous disc fragments, 104 EA patients (18.15%) experienced pain in the form of tingling spreading to the leg during dissection. These patients were given extra sedation and analgesia (fentanyl at 1 lg/kg and midazolam at 0.01 mg/kg), and the costs of these were added to total cost of the surgery. In the GA group, 1 mg/kg tramadol was administered at the end of the operation for pain control. The first analgesic medication was given at 82.5 ± 18.3 minutes (range: 40–130) after the patients left the recovery room. In the EA group, the first analgesic medication was given, on average, at 186.6 ± 21.1 minutes (range: 100–285; p < 0.01) after the patient left the recovery room. In both groups, the first choice analgesic was NSAID. All patients were mobilized within the first 6 hours after surgery. The length of hospital stay was 1.09 ± 0.38 and 1.1 ± 0.3 days for the EA and GA groups, respectively. There was no statistically significant difference in terms of length of hospital stay (p > 0.05).
3.1. Complications Of the 850 LMD surgeries, 63 (7.39%) had complications linked to the surgical procedure or anesthesia. Complications related to the LMD surgery (dural injury, infection, additional neurological deficits) occurred in 4.53% of EA patients and 5.05% of GA patients (p > 0.05) and complications related to anesthesia (unsuccessful EA, peripheral nerve, ophthalmological complications) were observed in 1.72% of EA patients and 4.69% of GA patients (p < 0.05; Table 4). For the 583 EA patients, if the EA was insufficient or unsuccessful (n = 9) or if a seizure occurred during the epidural injection (n = 1), the patients were converted to GA. The one patient with seizure had no previous history of epilepsy and no pathology was found on cranial MRI, therefore, this seizure was considered to
Table 4 Statistical comparison of complications of lumbar microdiscectomy by type of anesthesia n (%)
Epidural anesthesia*, 573 (67.4)
General anesthesia*, 277 (32.6)
Ophthalmologic complication, 4 (0.47) Unsuccessful epidural anesthesia, 10 (1.18) Peripheral nerve root complication, 9 (1.05) Total, 23 (2.7)
None
4 (1.44)
10 (1.72)a
None
Not applicable
9 (3.24)
10 (1.72)
13 (4.69)
*
A significant increase in the complication rate was observed in the GA group compared to the EA group (p < 0.05). a The complication rate in 583 patients who were given an EA injection. EA = epidural anesthesia, GA = general anesthesia.
Please cite this article in press as: Ulutas M et al. General versus epidural anesthesia for lumbar microdiscectomy. J Clin Neurosci (2015), http://dx.doi.org/ 10.1016/j.jocn.2015.02.018
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M. Ulutas et al. / Journal of Clinical Neuroscience xxx (2015) xxx–xxx
be caused by bupivacaine entering the circulation from an epidural vein. This patient’s surgery was completed 2 days later under GA. After surgery, 32 EA patients (5.6%) and 104 GA patients (37.5%) were given metoclopramide for nausea/vomiting (p < 0.01). None of the patients given EA developed urinary retention.
4. Discussion LMD is usually performed under GA but several studies on this surgery have been conducted under regional (epidural, spinal, or combined) anesthesia [3,4,7,8]. In recent years, spinal and EA methods have been determined to be effective and reliable for lumbar disc and laminectomy surgeries with reduced bleeding, postoperative pain, analgesic requirements, and nausea/vomiting rates, as well as none of the complications linked to GA and lower thromboembolism rates [3,6–11,13]. Although prospective studies of LMD with EA have shown feasibility and advantages over GA, no previous study has addressed EA cost effectiveness compared to GA [8,12]. In our study, the GA and EA costs were 9.35% and 5.4% of the fixed price paid by the Turkish Social Security Institution to cover all services (surgeon fees, anesthesia, supplies, accommodation), respectively. Thus, the use of EA resulted in a LMD cost of 43.28% less than when GA was used. In addition, EA patients turned themselves from the supine position to the prone position and vice versa, and did not require medications or additional time for extubation. As a result the EA patients could immediately leave the operating room, which reduced the time needed to clean the room and, ultimately, the time spent in the operating room, by 23.94% (p < 0.01). This important reduction in the time spent in the operating room resulted in reduced fees for the surgeon, anesthetist and assisting personnel and more efficient use of the operating room, making LMD with EA more economical than LMD with GA. Macario et al. also reported that the cost of anesthesia for various surgeries was only a small portion of the total hospitalization cost but that effective use of the operating room has significant downstream effects on the economy of surgery [8]. In Naderi’s study of all spinal operations recorded by the Turkish Social Security Institution in 2010, 2011 and 2012, a total of 214,691 lumbar disc surgeries were performed, and this number accounted for 63.6% of all spinal operations [9]. If all of those operations had been completed with EA, there would have been an estimated savings of 5,066,631 USD over 3 years. If 67.41% of those operations had been completed with EA, as in our study, the estimated savings would have been 3,415,416 USD over 3 years. The continuous development of modern technology in countries such as the USA, where health services are very expensive, increases the total cost of each LMD in those countries. Therefore, the use of EA in those countries could provide yearly savings of millions of dollars. The rate of neurological complications with spinal anesthesia is known to be higher than with EA [2,14,15]. The limitations of spinal anesthesia are its complications (cardiac arrest, respiratory arrest, neuropathy, cerebrospinal fluid leak, arachnoiditis, meningitis, headache, urinary retention) and the continuation of the motor and sensory block in the early postoperative period which prevents neurological examination after lumbar disc surgery [1]. Early neurological examination can easily be completed in patients operated under EA as their superficial sensation and motor strength remain intact during surgery. A major neurological complication (epileptic seizure) linked to EA injection occurred in only one patient (0.17%) in our series. When used effectively, EA prevents surgical pain, reduces postoperative narcotic and non-narcotic medication use and increases patient comfort during the postoperative period. In the current
study, although the GA patients received analgesia in the recovery room, they still required analgesia, on average, 82.5 ± 18.3 minutes after reaching the ward whereas the EA patients did not require analgesia until 186.6 ± 21.2 minutes after reaching the ward (p < 0.01). Thus, the EA patients used less analgesic medication. 4.1. Limitations 1. Retrospective data. 2. The calculation of cost was performed based on the invoice charged to the patient because the costs of drugs and materials from the hospital store could not be retrieved. 3. The cost calculation was performed for the anesthetic drugs and the surgical materials. The other costs (surgeon’s fee, anesthesiologist’s fee, time spent in the operating room, hospital investment) were not included in the calculation and this may have been a limiting factor. Wages differ between hospitals and can be difficult to compare. 4. The nausea/vomiting rate was determined based on metoclopramide use. 5. Conclusion The anesthetic method used during LMD surgery affects the complication rate, costs and efficiency of operating room use. We suggest that EA can contribute to savings in the health budget and allow LMD to be completed with greater effectiveness, reliability and cost efficiency, without affecting the success rate of the surgical procedure. Conflicts of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. References [1] Silver DJ, Dunsmore RH, Dickson CM. Spinal anesthesia for lumbar disc surgery: review of 576 operations. Anesth Analg 1976;55:550–4. [2] Smrcka M, Baudysova O, Juran V, et al. Lumbar disc surgery in regional anaesthesia – 40 years of experience. Acta Neurochir (Wien) 2001; 143:377–81. [3] Fernandez-Ordonez M, Tenias JM, Picazo-Yeste J. Spinal anesthesia versus general anesthesia in the surgical treatment of inguinal hernia. Costeffectiveness analysis. Rev Esp Anestesiol Reanim 2014;61:254–61. [4] Schuster M, Gottschalk A, Berger J, et al. A retrospective comparison of costs for regional and general anesthesia techniques. Anesth Analg 2005;100:786–94. [5] Zhang HW, Chen YJ, Cao MH, et al. Laparoscopic cholecystectomy under epidural anesthesia: a retrospective comparison of 100 patients. Am Surg 2012;78:107–10. [6] Jellish WS, Thalji Z, Stevenson K, et al. A prospective randomized study comparing short- and intermediate-term perioperative outcome variables after spinal or general anesthesia for lumbar disk and laminectomy surgery. Anesth Analg 1996;83:559–64. [7] Nicassio N, Bobicchio P, Umari M, et al. Lumbar microdiscectomy under epidural anaesthesia with the patient in the sitting position: a prospective study. J Clin Neurosci 2010;17:1537–40. [8] Macario A, Vitez TS, Dunn B, et al. Where are the costs in perioperative care? Analysis of hospital costs and charges for inpatient surgical care. Anesthesiology 1995;83:1138–44. [9] Naderi S. Analysis of spine surgery procedures performed in Turkey in 2010, 2011 and 2012 according to the Social Security Administration of Turkey [Turkish]. Türk Nörosßirürji Dergisi 2014;24:1–6. [10] De Rojas JO, Syre P, Welch WC. Regional anesthesia versus general anesthesia for surgery on the lumbar spine: a review of the modern literature. Clin Neurol Neurosurg 2014;119:39–43. [11] Demirel CB, Kalayci M, Ozkocak I, et al. A prospective randomized study comparing perioperative outcome variables after epidural or general anesthesia for lumbar disc surgery. J Neurosurg Anesthesiol 2003;15:185–92. [12] Khajavi MR, Asadian MA, Imani F, et al. General anesthesia versus combined epidural/general anesthesia for elective lumbar spine disc surgery: a randomized clinical trial comparing the impact of the two methods upon the outcome variables. Surg Neurol Int 2013;4:105.
Please cite this article in press as: Ulutas M et al. General versus epidural anesthesia for lumbar microdiscectomy. J Clin Neurosci (2015), http://dx.doi.org/ 10.1016/j.jocn.2015.02.018
M. Ulutas et al. / Journal of Clinical Neuroscience xxx (2015) xxx–xxx [13] Modig J, Borg T, Karlstrom G, et al. Thromboembolism after total hip replacement: role of epidural and general anesthesia. Anesth Analg 1983; 62:174–80. [14] Brull R, McCartney CJ, Chan VW, et al. Neurological complications after regional anesthesia: contemporary estimates of risk. Anesth Analg 2007; 104:965–74.
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[15] Auroy Y, Benhamou D, Bargues L, et al. Major complications of regional anesthesia in France: The SOS Regional Anesthesia Hotline Service. Anesthesiology 2002;97:1274–80.
Please cite this article in press as: Ulutas M et al. General versus epidural anesthesia for lumbar microdiscectomy. J Clin Neurosci (2015), http://dx.doi.org/ 10.1016/j.jocn.2015.02.018
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical Study
General versus epidural anesthesia for lumbar microdiscectomy Murat Ulutas a,⇑, Mehmet Secer b, Ozgur Taskapilioglu c, Soner Karadas d, Ahmet Aykut Akyilmaz d, Yunus Baydilek d, Betul Kocamer d, Ayse Ozboz d, Suat Boyaci e a
Department of Neurosurgery, Sanko University, Konukoglu Hospital, Ali Fuat Cebesoy Bulvari, Sßehitkamil 7090, Gaziantep, Turkey Department of Neurosurgery, Deva Hospital, Gaziantep, Turkey c Department of Neurosurgery, Uludag University Medical Faculty, Bursa, Turkey d Department of Anaesthesiology, Sanko University, Konukoglu Hospital, Gaziantep, Turkey e Department of Neurosurgery, Acibadem Hospital, Bursa, Turkey b
a r t i c l e
i n f o
Article history: Received 6 December 2014 Accepted 4 February 2015 Available online xxxx Keywords: Cost Epidural anesthesia General Lumbar microdiscectomy
a b s t r a c t This study was a retrospective analysis of 850 lumbar microdiscectomy (LMD) under epidural anesthesia (EA; n = 573) or general anesthesia (GA; n = 277) performed by the same surgeon and paid by invoice to the Social Security Institution of the Turkish Republic between April 2003 and May 2013. Although GA is the most frequently used method of anesthesia during LMD, the choice of regional anesthetia (epidural, spinal or a combination of these) differs between surgeons and anesthetists. Studies have reported that EA in surgery for lumbar disc herniation may be more reliable than GA, as it enables the surgeon to communicate with the patient during surgery, but few studies have compared the costs of these two anesthetic methods in LMD. We found that EA patient costs were significantly lower than GA patient costs (p < 0.01) and there was a statistically significant difference between the two groups in terms of the time spent in the operating room (p < 0.01). There was no difference in the duration of surgery (p > 0.05). The anesthetic method used during LMD affected the complication rate, cost and efficiency of operating room use. We suggest that EA is an anesthetic method that can contribute to health care cost savings and enable LMD to be completed with less nerve root manipulation and more comfort, efficacy, reliability and cost efficiency without affecting the success rate of the surgical procedure. Ó 2015 Elsevier Ltd. All rights reserved.
1. Introduction Symptoms related to lumbar disc herniation reduce the quality of everyday life and cause a loss of labor force productivity, and lumbar disc hernia surgery is one of the most frequently performed surgical procedures in neurosurgical practice. Surgical techniques for the treatment of lumbar disc herniation, such as microdiscectomy and endoscopic approaches, have been developed to reduce the duration of hospitalization and to allow a rapid return to daily life and work. In addition, the type of anesthesia used is important for reducing complications during and after surgery and can affect patient comfort. Although general anesthesia (GA) is the most frequently used method during lumbar microdiscectomy (LMD), the choice of a regional anesthetic (epidural, spinal or a combination of these) differs between surgeons and for different anesthetics. Studies have reported that epidural anesthesia (EA) in LMD may be more reliable than GA as it allows the surgeon to ⇑ Corresponding author. Tel.: +90 533 515 05 48; fax: +90 342 2115010. E-mail address: [email protected] (M. Ulutas).
communicate with the patient during surgery, but few studies have compared the costs of these two anesthetic methods in LMD surgery [1,2]. In general, the annual cost of minimally invasive approaches for LMD surgery has increased in parallel with the use of modern technology. When the cost of anesthesia is considered, the use of the most economical anesthetic method can significantly reduce the total cost of LMD surgery. For other surgical procedures, the costs of regional anesthetic and GA methods have been compared and it has been found that the cost of anesthesia is mainly related to its effect on surgical duration and whether the surgery can occur in an ambulatory setting [3– 5]. This retrospective investigation compared the length of time the operating room was occupied and the cost of anesthesia when EA and GA methods were used, and assessed EA reliability and applicability. Complications linked to patient position during GA (peripheral nerve compression, ophthalmological damage), complications linked to EA (unsuccessful EA, epilepsy) and general surgical complications (dural injury, infection, additional neurological deficits) were also examined and discussed with regard to the anesthetic method used.
http://dx.doi.org/10.1016/j.jocn.2015.02.018 0967-5868/Ó 2015 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Ulutas M et al. General versus epidural anesthesia for lumbar microdiscectomy. J Clin Neurosci (2015), http://dx.doi.org/ 10.1016/j.jocn.2015.02.018
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M. Ulutas et al. / Journal of Clinical Neuroscience xxx (2015) xxx–xxx
2. Methods Permission was granted by the Gaziantep Sanko University Sani Konukoglu Private Hospital Ethics Committee prior to retrospectively screening a total of 850 LMD under EA (n = 573) or GA (n = 277) performed by the same surgeon and financed by invoice to the Social Security Institution of the Turkish Republic between April 2003 and May 2013. All patients provided written consent for the surgical procedure and anesthetic method. Patients with radicular pain and/or neurological deficits linked to disc compression, as identified by imaging (MRI and CT scan), and who had no response to at least 3 weeks of conservative treatment, underwent a standard LMD with a surgical microscope (Leica M525 OH4; Leica Biosystems, Nussloch, Germany). Patients were recorded for age, sex, operated disc levels, duration in the operating room, duration of surgery, the patient’s first request for postoperative analgesia, the cost of anesthesia and complications. The duration in the operating room and the duration of surgery were obtained from the anesthesia monitoring form, and the EA and GA patients were compared based on these parameters. In the postoperative period, the time of the first analgesic request by the patient was obtained from the observation chart. 2.1. Anesthesia procedure All patients were given 1 mg of intravenous midazolam 30 minutes before the operation as a premedication. Additionally, antibiotic prophylaxis was given using 1 g of cefazolin before skin incision and 1 g every 8 hours postoperatively. Before induction in the GA group, 4 L/minute oxygen (O2) was given through a mask for preoxygenation. Induction was then conducted using 1 lg/kg remifentanil, 2–3 mg/kg propofol and 0.5 mg/kg rocuronium intravenously. After induction and oxygenation, intubation was performed with an endotracheal tube with a cuff. To maintain anesthesia, 0.25 lg/kg remifentanil, 2–2.5% sevoflurane and 4 L/minute fresh gas flow (50% O2/50% air mix) were administered. Before extubation, 1 ampule of a nonsteroidal anti-inflammatory drug (NSAID) and 0.5 mg/kg tramadol were administered. After approximately 30 minutes in the recovery room, the patient was sent to the ward. In the operating room, EA was administered in the sitting position under aseptic conditions at one or two levels above the operation field. After local anesthesia with subcutaneous prilocaine hydrochloride, an 18 gauge Tuohy needle was inserted into the epidural space using the loss of resistance method and a 14– 16 cm3 mix of 50 lg fentanyl (1 cm3), 100 mg lidocaine hydrochloride (5 cm3) and 50 mg bupivacaine (10 cm3) was administered. An epidural catheter was not inserted in any patients. After the injection, the patients were laid in a horizontal position. Following this, the surgical region and legs were checked for pain sensation using the pinprick test after which the patients were placed in the prone position. After the patients were settled in the most comfortable and appropriate prone position, they were sedated using 0.03 mg/kg midazolam. After 10 minutes in the recovery room in the postoperative period, they were moved to the ward. 2.2. Cost To calculate the direct costs for each patient, the intravenous and ıntramuscular medications used for anesthesia and the volatile anesthetics, single-use supplies, preoperative and postoperative analgesics and other medications used were considered. The time expenditure costs of personnel, surgeon and anesthetist fees, general costs of running the hospital such as electricity, water, air
conditioning and depreciation, and the aspects of LMD that were the same for both anesthetic methods such as surgical procedure medication, supplies and preoperative preparation (laboratory and radiology), were not included in the calculation. Because all ampules and vials were destroyed regardless of their remaining contents in accordance with the Turkish Ministry of Health’s Implementation Communiqué, the cost calculation for the ampules and vials was based on the numbers used. The data used for the cost calculation for each patient were obtained from the invoice information in the hospital computer system, which included the prices of anesthetic medications, supplies and postoperative analgesic medications. The prices of the medications used for anesthesia in the operations under EA or GA and the prices for postoperative analgesia were collected separately. The average cost was obtained in Turkish Liras (TL) and converted into US dollars (1 USD: 2.1 TL). The cost calculation for GA was performed based on the total price of anesthetic medications, intravenous fluids, postoperative analgesic medications (NSAID, tramadol) and supplies (intubation tubes, aspiration probes, intravenous catheters, injectors, disposable anesthetic breathing circuit devices, airway tubes). The costs of the medications used to treat side effects in the postoperative period such as nausea, vomiting, hypotension and bronchospasm were also added to the cost calculation. The cost calculation for EA included the costs of anesthetic medications (crystalloid, bupivacaine, prilocaine hydrochloride, fentanyl, lidocaine hydrochloride, midazolam), supplies (intravenous catheters, Tuohy needles, injectors) and postoperative analgesic medications (NSAID, tramadol). 2.3. Statistical analyses SPSS statistics (version 21; IBM Corporation, Armonk, NY, USA) was used for the statistical analyses. Descriptive statistics for continuous variables are given as the mean ± standard deviation and median (range) values. Comparisons between the groups were completed with Mann–Whitney tests and independent sample t-tests for continuous variables, and chi-squared tests for categorical variables. A correlation analysis was also completed. Statistical significance was accepted at p < 0.05.
3. Results A total of 850 LMD were completed in 797 patients (53 patients underwent repeat LMD due to recurrence at the same level); 573 surgeries were performed under EA and 277 were performed under GA. There was no significant difference between the EA and GA patients in terms of age or sex (p > 0.05; Table 1). Thirty-four of the operations performed under EA and 39 under GA were second operations performed for recurrence at the same level as that treated by the original surgery; 28 and 25 of those patients had undergone the original surgery at our clinic and 6 and 14 at other centers, for the EA and GA groups, respectively (Table 2).
Table 1 Demographic distribution of lumbar microdiscectomy patients by type of anaesthesia
Epidural anesthesia General anesthesia
LMD, n
Age, mean years ± SD
Age range, years*
Sex (M/F)*
573 277
44.2 ± 11.86 43.33 ± 11.18
20–76 20–70
328/245 158/119
* EA versus GA patients for age and sex (p > 0.05). F = female, LMD = lumbar microdiscectomy, M = male, SD = standard deviation.
Please cite this article in press as: Ulutas M et al. General versus epidural anesthesia for lumbar microdiscectomy. J Clin Neurosci (2015), http://dx.doi.org/ 10.1016/j.jocn.2015.02.018
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M. Ulutas et al. / Journal of Clinical Neuroscience xxx (2015) xxx–xxx Table 2 Level, side and recurrence of lumbar microdiscectomy in 850 patients n = 850
Level
Epidural anesthesia (573) n (%)
Level
General anesthesia (277) n (%)
One level, n = 705, 82.9%
L5–S1 L4–5 L3–4 L2–3 Total
209 (36.4) 264 (46.07) 27 (4.7) 1 (0.17) 501 (87.4)
Two levels, n = 55, 6.5%
L4–5, L5–S1 L3–4, L4–5 L3–4, L5–S1 Total L5–S1 L4–5 Total L5–S1 L4–5 L3–4 Total
16 (2.79) 8 (1.39) 1 (0.17) 25 (4.36) 4 (0.69) 9 (1.57) 13 (2.26) 17 (2.96) 14 (2.44) 3 (0.52) 34 (5.93)
L5–S1 L4–5 L3–4 L2–3 L1–2 Total L4–5, L5–S1 L3–4, L4–5 T12–L1, L5–S1 Total L4–5 L2–3 Total L5–S1 L4–5 L3–4 Total
82 (29.6) 107 (38.62) 10 (3.61) 3 (1.08) 2 (0.72) 204 (73.64) 15 (5.41) 14 (5.05) 1 (0.36) 30 (10.8) 3 (1.08) 1 (0.36) 4 (1.46) 13 (4.69) 24 (8.79) 2 (0.72) 39 (14.77)
Bilateral, n = 17, 2%
Recurrence, n = 73*, 8.6%
*
For 20 patients, the first operation was performed at a different hospital by an other surgeon, and for 53 patients the first operation was at our clinic.
Table 3 Average cost, duration of operating room occupation and duration of operation in lumbar microdiscectomy patients by type of anesthesia
General anesthesia Epidural anesthesia
Cost*, mean USD ± SD (range)
Duration of occupation of operating room*, mean minutes ± SD (range)
Duration of operation, mean minutes ± SD (range)
54.46 ± 21.81*** (22–131) 30.89 ± 11.88 (16–76)
107.6 ± 25.83*** (30–180) 81.84 ± 21.48 (30–180)
72.91 ± 21.35** (30–165) 67.7 ± 19.6** (20–155)
*
Time spent in the operating room versus the average cost for GA and EA groups, p < 0.01. Duration of operation (GA) versus duration of operation (EA) p > 0.05. *** Positive linear relationship between time spent in the operating room and the average cost for GA patients, p = 0.668. EA = epidural anesthesia, GA = general anesthesia, SD = standard deviation, USD = United States dollars. **
EA costs were significantly lower than GA costs (p < 0.01; Table 3). At hospitals that operate under an agreement with the Turkish Social Security Institution, a fixed compensation rate of 571.42 USD is paid for LMD surgery. Of this income, the portion used for medication supplies and analgesics is 5.4% for LMD surgeries performed under EA and 9.53% for those performed under GA. Thus, the EA group used 43.28% less funds than the GA group. While there was a statistically significant difference between the two groups in terms of time spent in the operating room (p < 0.01), there was no difference in the duration of surgery (p > 0.05). There was also a strong positive linear correlation between the time spent in the operating room and total cost (Table 3). Due to severe compression of the nerve root caused by subligamentous disc fragments, 104 EA patients (18.15%) experienced pain in the form of tingling spreading to the leg during dissection. These patients were given extra sedation and analgesia (fentanyl at 1 lg/kg and midazolam at 0.01 mg/kg), and the costs of these were added to total cost of the surgery. In the GA group, 1 mg/kg tramadol was administered at the end of the operation for pain control. The first analgesic medication was given at 82.5 ± 18.3 minutes (range: 40–130) after the patients left the recovery room. In the EA group, the first analgesic medication was given, on average, at 186.6 ± 21.1 minutes (range: 100–285; p < 0.01) after the patient left the recovery room. In both groups, the first choice analgesic was NSAID. All patients were mobilized within the first 6 hours after surgery. The length of hospital stay was 1.09 ± 0.38 and 1.1 ± 0.3 days for the EA and GA groups, respectively. There was no statistically significant difference in terms of length of hospital stay (p > 0.05).
3.1. Complications Of the 850 LMD surgeries, 63 (7.39%) had complications linked to the surgical procedure or anesthesia. Complications related to the LMD surgery (dural injury, infection, additional neurological deficits) occurred in 4.53% of EA patients and 5.05% of GA patients (p > 0.05) and complications related to anesthesia (unsuccessful EA, peripheral nerve, ophthalmological complications) were observed in 1.72% of EA patients and 4.69% of GA patients (p < 0.05; Table 4). For the 583 EA patients, if the EA was insufficient or unsuccessful (n = 9) or if a seizure occurred during the epidural injection (n = 1), the patients were converted to GA. The one patient with seizure had no previous history of epilepsy and no pathology was found on cranial MRI, therefore, this seizure was considered to
Table 4 Statistical comparison of complications of lumbar microdiscectomy by type of anesthesia n (%)
Epidural anesthesia*, 573 (67.4)
General anesthesia*, 277 (32.6)
Ophthalmologic complication, 4 (0.47) Unsuccessful epidural anesthesia, 10 (1.18) Peripheral nerve root complication, 9 (1.05) Total, 23 (2.7)
None
4 (1.44)
10 (1.72)a
None
Not applicable
9 (3.24)
10 (1.72)
13 (4.69)
*
A significant increase in the complication rate was observed in the GA group compared to the EA group (p < 0.05). a The complication rate in 583 patients who were given an EA injection. EA = epidural anesthesia, GA = general anesthesia.
Please cite this article in press as: Ulutas M et al. General versus epidural anesthesia for lumbar microdiscectomy. J Clin Neurosci (2015), http://dx.doi.org/ 10.1016/j.jocn.2015.02.018
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M. Ulutas et al. / Journal of Clinical Neuroscience xxx (2015) xxx–xxx
be caused by bupivacaine entering the circulation from an epidural vein. This patient’s surgery was completed 2 days later under GA. After surgery, 32 EA patients (5.6%) and 104 GA patients (37.5%) were given metoclopramide for nausea/vomiting (p < 0.01). None of the patients given EA developed urinary retention.
4. Discussion LMD is usually performed under GA but several studies on this surgery have been conducted under regional (epidural, spinal, or combined) anesthesia [3,4,7,8]. In recent years, spinal and EA methods have been determined to be effective and reliable for lumbar disc and laminectomy surgeries with reduced bleeding, postoperative pain, analgesic requirements, and nausea/vomiting rates, as well as none of the complications linked to GA and lower thromboembolism rates [3,6–11,13]. Although prospective studies of LMD with EA have shown feasibility and advantages over GA, no previous study has addressed EA cost effectiveness compared to GA [8,12]. In our study, the GA and EA costs were 9.35% and 5.4% of the fixed price paid by the Turkish Social Security Institution to cover all services (surgeon fees, anesthesia, supplies, accommodation), respectively. Thus, the use of EA resulted in a LMD cost of 43.28% less than when GA was used. In addition, EA patients turned themselves from the supine position to the prone position and vice versa, and did not require medications or additional time for extubation. As a result the EA patients could immediately leave the operating room, which reduced the time needed to clean the room and, ultimately, the time spent in the operating room, by 23.94% (p < 0.01). This important reduction in the time spent in the operating room resulted in reduced fees for the surgeon, anesthetist and assisting personnel and more efficient use of the operating room, making LMD with EA more economical than LMD with GA. Macario et al. also reported that the cost of anesthesia for various surgeries was only a small portion of the total hospitalization cost but that effective use of the operating room has significant downstream effects on the economy of surgery [8]. In Naderi’s study of all spinal operations recorded by the Turkish Social Security Institution in 2010, 2011 and 2012, a total of 214,691 lumbar disc surgeries were performed, and this number accounted for 63.6% of all spinal operations [9]. If all of those operations had been completed with EA, there would have been an estimated savings of 5,066,631 USD over 3 years. If 67.41% of those operations had been completed with EA, as in our study, the estimated savings would have been 3,415,416 USD over 3 years. The continuous development of modern technology in countries such as the USA, where health services are very expensive, increases the total cost of each LMD in those countries. Therefore, the use of EA in those countries could provide yearly savings of millions of dollars. The rate of neurological complications with spinal anesthesia is known to be higher than with EA [2,14,15]. The limitations of spinal anesthesia are its complications (cardiac arrest, respiratory arrest, neuropathy, cerebrospinal fluid leak, arachnoiditis, meningitis, headache, urinary retention) and the continuation of the motor and sensory block in the early postoperative period which prevents neurological examination after lumbar disc surgery [1]. Early neurological examination can easily be completed in patients operated under EA as their superficial sensation and motor strength remain intact during surgery. A major neurological complication (epileptic seizure) linked to EA injection occurred in only one patient (0.17%) in our series. When used effectively, EA prevents surgical pain, reduces postoperative narcotic and non-narcotic medication use and increases patient comfort during the postoperative period. In the current
study, although the GA patients received analgesia in the recovery room, they still required analgesia, on average, 82.5 ± 18.3 minutes after reaching the ward whereas the EA patients did not require analgesia until 186.6 ± 21.2 minutes after reaching the ward (p < 0.01). Thus, the EA patients used less analgesic medication. 4.1. Limitations 1. Retrospective data. 2. The calculation of cost was performed based on the invoice charged to the patient because the costs of drugs and materials from the hospital store could not be retrieved. 3. The cost calculation was performed for the anesthetic drugs and the surgical materials. The other costs (surgeon’s fee, anesthesiologist’s fee, time spent in the operating room, hospital investment) were not included in the calculation and this may have been a limiting factor. Wages differ between hospitals and can be difficult to compare. 4. The nausea/vomiting rate was determined based on metoclopramide use. 5. Conclusion The anesthetic method used during LMD surgery affects the complication rate, costs and efficiency of operating room use. We suggest that EA can contribute to savings in the health budget and allow LMD to be completed with greater effectiveness, reliability and cost efficiency, without affecting the success rate of the surgical procedure. Conflicts of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. References [1] Silver DJ, Dunsmore RH, Dickson CM. Spinal anesthesia for lumbar disc surgery: review of 576 operations. Anesth Analg 1976;55:550–4. [2] Smrcka M, Baudysova O, Juran V, et al. Lumbar disc surgery in regional anaesthesia – 40 years of experience. Acta Neurochir (Wien) 2001; 143:377–81. [3] Fernandez-Ordonez M, Tenias JM, Picazo-Yeste J. Spinal anesthesia versus general anesthesia in the surgical treatment of inguinal hernia. Costeffectiveness analysis. Rev Esp Anestesiol Reanim 2014;61:254–61. [4] Schuster M, Gottschalk A, Berger J, et al. A retrospective comparison of costs for regional and general anesthesia techniques. Anesth Analg 2005;100:786–94. [5] Zhang HW, Chen YJ, Cao MH, et al. Laparoscopic cholecystectomy under epidural anesthesia: a retrospective comparison of 100 patients. Am Surg 2012;78:107–10. [6] Jellish WS, Thalji Z, Stevenson K, et al. A prospective randomized study comparing short- and intermediate-term perioperative outcome variables after spinal or general anesthesia for lumbar disk and laminectomy surgery. Anesth Analg 1996;83:559–64. [7] Nicassio N, Bobicchio P, Umari M, et al. Lumbar microdiscectomy under epidural anaesthesia with the patient in the sitting position: a prospective study. J Clin Neurosci 2010;17:1537–40. [8] Macario A, Vitez TS, Dunn B, et al. Where are the costs in perioperative care? Analysis of hospital costs and charges for inpatient surgical care. Anesthesiology 1995;83:1138–44. [9] Naderi S. Analysis of spine surgery procedures performed in Turkey in 2010, 2011 and 2012 according to the Social Security Administration of Turkey [Turkish]. Türk Nörosßirürji Dergisi 2014;24:1–6. [10] De Rojas JO, Syre P, Welch WC. Regional anesthesia versus general anesthesia for surgery on the lumbar spine: a review of the modern literature. Clin Neurol Neurosurg 2014;119:39–43. [11] Demirel CB, Kalayci M, Ozkocak I, et al. A prospective randomized study comparing perioperative outcome variables after epidural or general anesthesia for lumbar disc surgery. J Neurosurg Anesthesiol 2003;15:185–92. [12] Khajavi MR, Asadian MA, Imani F, et al. General anesthesia versus combined epidural/general anesthesia for elective lumbar spine disc surgery: a randomized clinical trial comparing the impact of the two methods upon the outcome variables. Surg Neurol Int 2013;4:105.
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