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ORIGINAL ARTICLE
Year : 2020  |  Volume : 4  |  Issue : 6  |  Page : 44-49

A randomized controlled trial on epidural volume extension in combined spinal epidural anesthesia for lower limb surgeries using intrathecal ropivacaine in older adults


1 Department of Anaesthesiology, AIIMS, Patna, Bihar, India
2 Department of Anaesthesiology and Critical Care, UPUMS, Saifai, Uttar Pradesh, India
3 Senior Resident, Critical Care, KGMU, Lucknow, Uttar Pradesh, India
4 Department of Anaesthesiology, SKMCH, Muzaffarpur, Bihar, India
5 Department of Anatomy, AIIMS, Patna, Bihar, India

Date of Submission04-May-2020
Date of Decision10-Jun-2020
Date of Acceptance25-Jun-2020
Date of Web Publication05-Oct-2020

Correspondence Address:
Dr. Shagufta Naaz
Department of Anesthesiology, AIIMS, Patna, Bihar
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/BJOA.BJOA_75_20

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  Abstract 


Background: Epidural volume extension (EVE) is a technique wherein normal saline is injected into epidural space, soon after the neuraxial block. We studied the effectiveness of EVE using intrathecal ropivacaine and normal saline in the elderly. Patients and Methods: This was randomized, control, double-blinded, double arm, parallel study of 75 patients of American Society of Anesthesiologists I and II, age ≥60 years, undergoing lower limb orthopedic surgery. Patients were allocated into two groups (E and NE), both receiving 3 ml of 0.75% injection ropivacaine intrathecally. Group E also received EVE. The primary outcome was the maximum level of sensory block. Secondary outcomes were the characteristics of blocks, hemodynamic changes, adverse effects, and analgesic requirements until 24 h. The statistical analysis of quantitative data was done by the Student's t-test and that of qualitative data using the Chi-square test. Results: The sensory level of block achieved in Group E T4(T2–T5) was higher as compared to Group NE, T6(T3-T8). Time to two-segment sensory regression was earlier in Group NE (mean = 66.5 min; 95% confidence interval [CI], 63.31–69.69) than in Group E (mean = 91.5 min; 95% CI, 87.70–95.31) (P < 0.001; df = 58). The duration of analgesia in Group E (mean = 316.5 min; 95% CI, 309.09–323.91) was more than in Group NE (mean = 230.67 min; 95% CI, 226.49–234.850) (P < 0.001). There was no statistically significant difference in the 24 h analgesic consumption (P = 0.64), hemodynamic stability, or adverse effects. Conclusion: EVE results in a higher level of the sensory block and a longer duration of postoperative analgesia than that without EVE with no hemodynamic instability in the older population.

Keywords: Epidural space, hemodynamic stability, local anesthetic, pain management, ropivacaine


How to cite this article:
Naaz S, Shukla U, Gupta R, Ozair E, Asghar A. A randomized controlled trial on epidural volume extension in combined spinal epidural anesthesia for lower limb surgeries using intrathecal ropivacaine in older adults. Bali J Anaesthesiol 2020;4, Suppl S2:44-9

How to cite this URL:
Naaz S, Shukla U, Gupta R, Ozair E, Asghar A. A randomized controlled trial on epidural volume extension in combined spinal epidural anesthesia for lower limb surgeries using intrathecal ropivacaine in older adults. Bali J Anaesthesiol [serial online] 2020 [cited 2020 Oct 22];4, Suppl S2:44-9. Available from: https://www.bjoaonline.com/text.asp?2020/4/6/44/297908




  Introduction Top


Epidural volume extension (EVE) is a modification of combined spinalepidural anesthesia (CSEA) technique, wherein normal saline is injected into epidural space, soon after the intrathecal dose, as part of CSEA.[1],[2] The injected volume of fluid in the epidural space causes compression of the dural sac resulting in cephalad spread of local anesthetic present in subarachnoid space.[3] Thus, one of the suggested benefits of EVE is a reduction in the local anesthetic dose required to achieve a level of the block that can be achieved without EVE and may lead to better hemodynamic stability.[4]

It has been identified that the high levels of sensory anesthesia and increasing age are the two main risk factors responsible for spinal hypotension.[5] In the elderly, the incidence of hypotension following spinal anesthesia is 25%–69%.[6] We hypothesized that EVE could reduce the incidence of hemodynamic side effects in older adults by achieving a higher level of the sensory block using a volume of local anesthetic that achieves a lower level of the block without EVE. Using ropivacaine for the neuraxial block in this population in EVE may further add to the benefit in the case of the older population due to less cardiotoxicity associated with it. No previous study has been done on EVE in this age group.

In this study, we aimed to appraise the effectiveness of EVE using intrathecal 0.75% ropivacaine and 10 ml of 0.9% normal saline. Studying the level of maximum sensory block in older patients posted for orthopedic surgery was the primary objective. The secondary objectives were to study the time to reach maximum sensory block, two-segment regression time of the sensory block, motor block characteristics, duration of analgesia, the total dose of systemic analgesic consumed in 24 h, to assess the hemodynamic variables and any side effects.


  Patients and Methods Top


After approval of the Institutional Ethical Committee and obtaining written informed consent from the participants, the randomized, double-blind placebo-controlled study was conducted in a tertiary medical institution as per the Helsinki Declaration. The study was conducted from May 2017 to May 2018. Patients of American Society of Anesthesiologists (ASA) 1 and 2, of either sex, aged 60 years and above, having a height between 150 and 175 cm and weight between 40 and 85 kg, presenting for elective lower limb orthopedic surgeries in the supine position were taken. Patients on anticoagulants, with any bleeding disorder, neurological deficit, history of drug allergy to local anesthetics, local infection, or known autonomic neuropathy were excluded from the study. Withdrawal criteria for the study included failed block, failure to insert an epidural catheter or any complication during the procedure.

Sample size estimation was done based on the previous study.[7] Patients were randomized into two groups using the computer-generated random numbers and opaque-sealed numbered envelope technique, Group E (who received CSEA with EVE of normal saline), and Group NE (who received combined spinal-epidural alone). The random allocation sequence was generated, and the participants were enrolled by the nursing staff not involved in the study. The study drugs were given by the anesthesiologist, who was aware of patient group allocation. The data were recorded by another anesthesiologist who was blinded to the group allocation and technique of block, and so were the participants.

All patients received tab ranitidine 150 mg and alprazolam 0.25 mg at the night and morning before the surgery. On arriving in the operation room, an intravenous line was secured with 18G intravenous cannula and all the patients preloaded with 15 ml/kg ringer lactate solution. All the standard monitors were attached. Under all aseptic precautions in the sitting position, 1.5 ml of 2% lignocaine was injected over the skin after identifying L4–L5 interspace. 18G Touhy needle was inserted, and epidural space identified through loss of resistance technique using 2 ml of air. After getting epidural space, a 27G Whitacre needle was inserted into subarachnoid space using a needle through the needle technique and 3 ml of 0.75% ropivacaine given. Then, an epidural catheter was placed in the epidural space through the Touhy needle and 10 ml of 0.9% sterile preservative-free normal saline injected within 5 min of performing subarachnoid block in Group E and only 3 ml of 0.75% ropivacaine was injected in intrathecal space in Group NE.

A blinded researcher entered the room after the patient lay supine on completion of the procedure. Sensory testing was done by the loss of pin-prick sensation to 23G hypodermic needle for onset and dermatomal levels. Levels were tested every min until the highest level had stabilized by continuous testing. After this, dermatomal levels were tested every 10 min until the effect regressed by two segments. Thereafter, it was tested every 20 min till the sensation was felt at S1 dermatome. Data regarding the highest level of block, time to reach the highest dermatomal level of sensory blockade from the time of injection, and two-segment regression times were collected. Motor testing was done at the same interval as sensory until complete recovery by using the Modified Bromage Scale. The blinded researcher assessed analgesia using a verbal rating scale 0–10 (where 0 = no pain and 10 = worst imaginable pain). Hemodynamic monitoring was done and data recorded after the block every 5 min for 30 min; then, at 15 min up to 120 min and 30 min interval until the end of surgery.

After the surgery, patients were shifted to the postanesthesia care and recovery unit where they were kept until there was the complete recovery of sensory and motor blockade. Whenever the patient experienced pain at any hour (Verbal Rating Scale ≥3), intramuscular injection diclofenac 1.5 mg/kg was administered (analgesia on demand). Postoperatively, first demand of analgesic agent, the total dose of analgesic agent requirement in 24 h, vital parameters were recorded, and also adverse events such as nausea, vomiting, and pruritus, were noted. Oxygen was administered through a mask if pulse oximetry reading decreased below 95%. Hypotension, defined as a decrease in systolic blood pressure by more than 20% from baseline or <90 mmHg, was treated with incremental doses of 6 mg mephentermine and further intravenous fluid as required. Bradycardia defined as a heart rate (HR) <50 beats/min was treated with intravenous atropine 0.6 mg. Shivering was assessed during the perioperative period and treated by intravenous 1 mg/kg tramadol, and these patients were excluded from the study. If nausea or pruritus required the treatment, it was also recorded.

The statistical analysis was executed with the help of the SPSS software 24.0 version (IBM, New York, United States). The measured outcomes were expressed as mean, standard deviation, and range. Frequencies were expressed as number and percentage. In order to check for the normalcy of distribution, the Kolmogorov–Smirnov test was applied. The student t-test was utilized for the analysis of quantitative data having a normal distribution. A Chi-square test was used to analyze the qualitative data and quantitative data, which did not pass the normality test. P < 0.05 was considered to be statistically significant and <0.01 highly significant.


  Results Top


Eighty-two patients were assessed for enrollment; 75 were randomly assigned into two groups, and 60 were analyzed [Figure 1]. The groups were comparable regarding age, sex, weight, height, body mass index, ASA status, and surgery time, as there was no significant difference between the groups [Table 1].
Figure 1: Consort flow diagram

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Table 1: Demographic Data

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[Table 2] shows the result related to the characteristics of the block. The maximum level of sensory block achieved was T4 (T2–T5) in patients belonging to Group E, and it was T6 (T3–T8) in patients belonging to Group NE. The difference was significant between the two groups (P = 0.01). The time to reach the maximum sensory block was earlier in Group E (mean 5.7 min; 95% confidence interval [CI], 5.04–6.37) than in Group NE (mean 10.2 min; 95% CI, 9.38–11.02) and the difference between the two was very significant (P < 0.001; df = 58). The time to two segments, sensory regression, was significantly less in Group NE (66.5 min [95% CI = 63.31–69.69]) than in Group E (91.5 min [95% CI = 87.70–95.31]), (P < 0.001). Time to reach maximum motor block was significantly less in Group E (3.3 min [95% CI = 3.11–3.49]) as compared to Group NE (4.50 min [95% CI = 3.96–5.04]), (P < 0.001). Group E took a significantly longer time for the Bromage score to achieve zero scores (248.5 min [95% CI = 255.36–241.64]) when compared to Group NE (171.5 min [95% CI = 166.84–176.16]), P < 0.001.
Table 2: Characteristics of sensory and motor blocks in the groups (minutes)

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The duration of analgesia in Group E (316.5 ± 20.71 min, 95% CI = 309.09–323.91) was significantly more than in Group NE (230.67 min, 95% CI = 226.49–234.850), P < 0.001, but the total analgesic consumption in 24 h did not differ significantly between the two groups [Table 2]. Group E had more hemodynamic stability as compared to Group NE, as displayed in [Figure 2] and [Figure 3], but the difference was not significant. Group E had less adverse effect than Group NE effects, but it was statistically insignificant [Table 3].
Figure 2: Comparison of MBP between the groups across the time periods

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Figure 3: Comparison of HR (beats/min) between the groups across the time periods

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Table 3: Comparison of complications between the groups

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  Discussion Top


As much as we know, this is the first clinical trial to study the effect of EVE for the older age group and that too using ropivacaine as a local anesthetic. We found a significant difference between the groups concerning maximum sensory dermatome level or the time to maximum dermatome level. Group E achieved a higher level of sensory block in significantly less time.

The effect of epidural saline injection on the analgesic level during CSEA was studied clinically and myelographically.[8] It demonstrated that the contrast medium in the subarachnoid space was displaced in a cephalad direction after lumbar epidural injection of saline and that the given volume narrowed the diameter of subarachnoid space.

In a study, 4 ml air was inserted through Touhy needle in the epidural space comparing with single-shot spinal, and it was found that patients with EVE achieved a higher sensory level of block up to T4 level as compared to T10 level in patients without EVE.[9]

This effect can be utilized in older patients by using the dose of a local anesthetic to achieve the height of block for which more drugs would be required had the EVE not been done.

EVE with saline in CSEA for hip surgeries using low-dose intrathecal hyperbaric bupivacaine was associated with the early onset of motor and sensory block, a higher level of sensory block, and shorter time of two-segment regression.[9] Similarly, in our study, we found that Group E with EVE had a higher level of block, time to onset of sensory and motor block in Group E was earlier than that in Group NE. However, in our study, the time to two-segment sensory regression was more in Group E.

In another study, low dose hyperbaric bupivacaine with EVE was associated with early onset and a higher level of sensory blockade, longer two-segment regression time, and early onset of motor blockade while maintaining hemodynamic stability.[10] This was in keeping with our study.

In a research paper comparing hydroxyethyl starch and normal saline for EVE in CSEA with no EVE, there was a statistically significant difference between the groups in the time required to reach maximum motor block (Bromage 3).[11] Our study had a similar result where the maximum motor block was achieved significantly earlier in Group E.

The results regarding motor recovery after EVE are variable in the literature. In our study, the time to recovery from the motor block (Bromage 0) was significantly more in Group E as compared to Group NE. In a study done by Guha S et al. on quality and extent of intrathecal bupivacaine block by extradural injection of bupivacaine or normal saline in CSEA, it was found that there was no significant difference in the mean duration of motor block among the groups.[12]

Another study on the effect of epidural top-up with saline in CSEA in patients undergoing transurethral resection of the prostate with only intrathecal drug found that there was no statistically significant difference in time to complete recovery from the motor block.[13]

In a few previous studies, there was a trend for less motor block in group EVE.[14] It was hypothesized that the EVE in the sitting position might have accelerated the spread of hyperbaric bupivacaine into sacral segments, and it was trapped there due to the curvature of the spine on lying flat. This compromised motor block, as sacral roots have no significant contribution to the motor function of the lower limb.[15] Others have explained it to be due to the compression of duramater causing the spread of intrathecal, local anesthetic, and thus decreasing the concentration of local anesthetic at the lumbar dermatomes, the major contributors to lower limb motor function, where the injection took place.[16] However, our study did not show earlier motor recovery in Group E. Lumbar canal stenosis and associated epidural venous varicosity are common in the elderly (above 60 years old), which impede the venous absorption in epidural space resulting in prolonging the effect of intrathecal drugs.[17] This might be responsible for the prolonged motor as well as sensory block in the current study. The slower rate of metabolism of local anesthetics in the elderly might also have contributed to this. Moreover, most of the studies in which earlier motor recovery has been seen have used a lower intrathecal volume of drugs for EVE as compared to the control group.[18] We have used an equal volume of drugs in intervention as well as the control group, which may account for the difference in motor recovery outcomes between different studies.

In our study, time to first rescue analgesia was significantly more in Group E as compared to Group NE. A study was conducted by Kaur S et al.[19] on EVE in which they found no difference between the groups regarding sensory block duration and the time to first request for postoperative analgesia.

One of the study of the reinforcement of subarachnoid block by epidural volume effect concluded that groups, where normal saline was used with fentanyl and tramadol, provided postoperative analgesia for the maximum duration. In contrast, the group with no EVE had a shorter duration of analgesia.[20] This is consistent with our study results. Slower absorption of the local anesthetic in compressed blood vessels of the spine with epidural saline is the probable cause.

Previously, no study was done for the total analgesic requirement in 24 h. In our study, we observed that although EVE increased the duration of analgesia, there was no significant difference between the total analgesic requirements for 24 h in both groups.

In a previous study, it has been observed that there was no significant difference between hemodynamic parameters (HR, systolic, and diastolic blood pressure) among the two groups, and our study had a similar outcome.[10] The elderly population has decreased physiologic reserve and increased incidence of systemic disease, particularly cardiovascular disease, which makes them prone to long-term complications even with brief episodes of uncorrected hypotension.[21] EVE will provide hemodynamic stability in older patients who have a high probability of developing hypotension if a higher dose of local anesthetic is injected to achieve the same height of the block.

Case reports of its use in parturients with cardiac comorbidities or in patients with reduced left ventricular function have suggested the possible use of EVE for more stable hemodynamics when using intrathecal block.[22] However, the more excellent hemodynamic stability seen with EVE may likely be attributable to the relative decrease in the local anesthetic dose rather than a direct effect of EVE.

A meta-analysis was also done taking 18 randomized controlled trials on parturients using intrathecal bupivacaine with EVE.[18] They concluded that EVE in CSEA is associated with a higher level of sensory block, early motor recovery, decreased intraoperative analgesic requirement, and no significant difference for postoperative analgesia between the groups. Similar results were also found in this study except for early motor recovery.

Few adverse effects such as hypotension, bradycardia, nausea, and vomiting, were present in both groups, but there was no significant difference between groups. Other studies have also shown insignificant or less adverse effects with EVE as compared to the control group.[18],[23]

The limitation of the study is that the patients of Group E were made to lie supine a few minutes later than that of Group NE. However, that is not expected to have made a significant difference. The second limitation that epidural catheter was not used for postoperative analgesia. Nevertheless, this was done to calculate the 24-h analgesic requirement to study the postoperative analgesic effects of EVE.


  Conclusion Top


A higher level of a block can be achieved with EVE using the same dose of the local anesthetic as that in case of neuraxial anesthesia without EVE. More local anesthetic means more chances of hemodynamic instability, especially in the older age group. Thus EVE is a good option for the conduct of neuraxial block by using a lower dose of local anesthetic than conventionally used to attain a similar height of the block and getting hemodynamic stability. We recommend using this method in the older population.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

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Hakim KY. Comparative study between sequential combined spinal epidural anesthesia versus epidural volume extension in lower limb surgery. Ain Shams J Anesthesiol 2020;12:1-6.  Back to cited text no. 1
    
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McNaught AF, Stocks GM. Epidural volume extension and low-dose sequential combined spinal-epidural blockade: Two ways to reduce spinal dose requirement for caesarean section. Int J Obstet Anesth 2007;16:346-53.  Back to cited text no. 2
    
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Fujita N, Higuchi H, Zhang K, Takagi S, Ozaki M. Distribution of epidural saline upon injection and the epidural volume effect in pregnant women: 11AP3-2. Eur J Anaesthesiol 2011;28:161.  Back to cited text no. 3
    
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Lew E, Yeo SW, Thomas E. Combined spinal-epidural anesthesia using epidural volume extension leads to faster motor recovery after elective cesarean delivery: A prospective, randomized, double-blind study. Anesth Analg 2004;98:810-4.  Back to cited text no. 5
    
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Zaphiratos V, George RB, Macaulay B, Bolleddula P, McKeen DM. Epidural volume extension during combined spinal-epidural labor analgesia does not increase sensory block. Anesth Analg 2016;123:684-9.  Back to cited text no. 7
    
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Takiguchi T, Okano T, Egawa H, Okubo Y, Saito K, Kitajima T. The effect of epidural saline injection on analgesic level during combined spinal and epidural anesthesia assessed clinically and myelographically. Anesth Analg 1997;85:1097-100.  Back to cited text no. 8
    
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Goy RW, Sia AT. Sensorimotor anesthesia and hypotension after subarachnoid block: Combined spinal-epidural versus single-shot spinal technique. Anesth Analg 2004;98:491-6.  Back to cited text no. 9
    
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Bhandari RS, Bhatia R, Agrawal S. Epidural volume extension with saline in combined spinal-epidural anesthesia for hip surgeries using low dose of intrathecal hyperbaric bupivacaine. Anesth Essays Res 2018;12:145-8.  Back to cited text no. 10
[PUBMED]  [Full text]  
11.
Gupta S, Sinha N, Surendran K, Naithani U, Doshi V, Bedi V. Comparison of hydroxyethyl starch versus normal saline for epidural volume extension in combined spinal epidural anesthesia for cesarean section. J Obstet Anaesth Crit Care 2012;2:16.  Back to cited text no. 11
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12.
Guha Banerjee S, Bandyopadhyay U, Pan PK, Sinha A. Study of quality and extent of intrathecal bupivacaine block by extradural injection of bupivacaine or normal saline in combined spinal epidural technique. Anesth Essays Res 2014;8:54-8.  Back to cited text no. 12
    
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Gokce M, Hanci A, Eksioglu B, Sivrikaya G, Dobrucali H. 53: The effects of epidural top-up technique wİth saline in spinal anesthesia. Regional Anesthesia and Pain Medicine. BMJ 2007;32:37.  Back to cited text no. 13
    
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