Table of Contents  
ORIGINAL ARTICLE
Year : 2017  |  Volume : 10  |  Issue : 1  |  Page : 213-218

Effect of addition of hyaluronidase as an adjuvant to local anesthetics in ultrasound-guided supraclavicular brachial plexus block


Department of Anesthesia, Faculty of Medicine, Ain Shams University, Cairo; Department of Anesthesia, Faculty of Medicine, Fayoum University, Faiyum, Egypt

Date of Web Publication3-Aug-2018

Correspondence Address:
Karim Y kamal Hakim
karimykhakim@hotmail.com
Egypt
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1687-7934.238458

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  Abstract 


Background This study was carried out to evaluate the efficacy of hyaluronidase as an adjuvant to the mixture of local anesthetics in ultrasound-guided supraclavicular brachial plexus block.
Patients and methods Ninety patients received ultrasound-guided brachial plexus block through supraclavicular approach. They were then randomly divided into three groups: group C, group H1, and group H2. Group C patients received 2% (15 ml) lignocaine and 0.5% (15 ml) bupivacaine, making a total volume of 30 ml, by triple-injection technique. Group H1 patients received 2% (10 ml) lignocaine and 0.5% (10 ml) bupivacaine plus 0.9% (10 ml) normal saline containing 900 IU (90 IU/ml) hyaluronidase, making a total volume of 30 ml, by triple-injection technique. Group H2 patients received 2% (10 ml) lignocaine and 0.5% (10 ml) bupivacaine plus 0.9% (10 ml) normal saline containing 900 IU (90 IU/ml) hyaluronidase, making a total volume of 30 ml, by single-injection technique. Parameters such as needling time, onset of sensory block, onset of motor block, total dose of intraoperative rescue analgesics, rate of success of the block, duration of sensory block, duration of motor block, and possible side effects were measured.
Results Time needed to perform the block was significantly shorter in the H2 group compared with the C and H1 groups. Onset of sensory block was statistically significantly lower in the two groups in which hyaluronidase was used compared with that in group C. Onset of motor block was statistically significantly lower in H1 and H2 groups compared with that in group C. The mean total intraoperative fentanyl administration was found to be nonsignificantly higher in group C compared with groups H1 and H2. The success of the ultrasound-guided block was 90% in group C versus 96.6% in groups H1 and H2. As regards the duration of sensory and motor block there were no statistically significant differences between the three studied groups. Comparison between the three groups revealed nonsignificant differences as regards the time of first analgesic dose. The total dose of morphine given during the first 24 h postoperatively was significantly lower in the control group compared with that in groups H1 and H2.
Conclusion The use of hyaluronidase as an adjuvant to the local anesthetic reduces the time to reach complete sensory block of ultrasound-guided supraclavicular brachial plexus blocks and therefore shortens the total anesthetic time before operation. Although it also reduces the block duration, hyaluronidase had only a little effect on the total analgesic duration and on the consumption of postoperative analgesics. Also single-injection technique is sufficient for performing a successful block.

Keywords: bupivacaine, hyaluronidase, supraclavicular brachial plexus block, ultrasound


How to cite this article:
Hakim KY, Ahmed MA. Effect of addition of hyaluronidase as an adjuvant to local anesthetics in ultrasound-guided supraclavicular brachial plexus block. Ain-Shams J Anaesthesiol 2017;10:213-8

How to cite this URL:
Hakim KY, Ahmed MA. Effect of addition of hyaluronidase as an adjuvant to local anesthetics in ultrasound-guided supraclavicular brachial plexus block. Ain-Shams J Anaesthesiol [serial online] 2017 [cited 2018 Nov 20];10:213-8. Available from: http://www.asja.eg.net/text.asp?2017/10/1/213/238458




  Introduction Top


Ultrasound-guided supraclavicular brachial plexus block is a popular regional anesthetic technique for the upper limb, and has multiple applications [1]. Ultrasound is useful in providing clinicians with a real-time image for visualizing anatomical structures, needle placement, and local anesthetic (LA) spread [2]. The supraclavicular block of the brachial plexus has many advantages over other approaches to brachial plexus block. It has the reputation of providing the most complete and reliable anesthesia for upper-limb surgery. It is performed at the trunk level where the plexus is presented most compactly. This anatomic compactness is responsible for complete and reliable anesthesia [3].

Single-injection (SI) ultrasound-guided technique in the corner pocket has been reported to have the highest success rate; this technique may miss the upper part of the plexus, resulting in an incomplete block [4]. Fascia or a tight muscular membrane between the scalene muscles was found to separate roots of the plexus [5]. Several studies showed that multiple injection techniques were more successful, resulting in a faster onset of anesthesia and higher success rates, with no increased incidence in complications [6],[7].

LAs with additives have been used to prolong regional blockade. Vasoconstrictors can be used to vasoconstrict vessels, thereby reducing vascular absorption of the LA. Additives like opioids, clonidine, dexmedetomidine, and steroids were added to LAs, but the results are either inconclusive or associated with side effects [8],[9],[10].

Hyaluronidase acts by catalyzing the hydrolysis of hyaluronan. A constituent of the extracellular matrix, hyaluronidase lowers the viscosity of hyaluronan, thereby increasing tissue permeability. It is therefore used in medicine in conjunction with other drugs to speed up their dispersion and delivery. Common applications are ophthalmic surgery, in combination with LAs. It also increases the absorption rate of parenteral fluids given by hypodermoclysis, and is an adjunct in subcutaneous urography for improving the resorption of radiopaque agents. Hyaluronidase is also used to treat extravasation of hyperosmolar solutions [11].

This study was carried out to evaluate the efficacy of hyaluronidase as an adjuvant to the mixture of LAs in ultrasound-guided supraclavicular brachial plexus block.


  Patients and methods Top


The study was conducted in Ain Shams and Fayoum University Hospitals at the Orthopedic Surgery Departments from June 2014 to January 2016. After obtaining approval from the universities’ ethical committee and written informed consent from the patients, 90 patients were included in this study. The study population included patients of both sexes, of ASA grade 1 and 2, aged 18–60 years. Patients were scheduled for upper-extremity surgeries below the shoulder joint and received ultrasound-guided brachial plexus block through supraclavicular approach. Our study was a randomized, prospective, double-blinded, controlled study. Patients excluded from our study were those with bleeding disorders or on anticoagulants, those with severe respiratory disease, neurological deficit involving the brachial plexus, local infection at the injection site, history of allergy to LAs or hyaluronidase, or mental retardation, and those who refused to participate.

Preoperative investigations in the form of ECG, chest radiograph (if indicated, in patients younger than 40 years), complete blood picture, and coagulation profile were conducted. Details of the anesthetic technique and study protocol were explained to the patients at the preoperative visit. An intravenous line was inserted; all patients received midazolam 1–2 mg. Basic monitors were attached (ECG, pulse oximeter, NIBP). The patients were then randomly divided into three groups (30 patients each) using a computer-generated table of random numbers.

Group C: Patients in this group received 2% (15 ml) lignocaine and 0.5% (15 ml) bupivacaine, making a total volume of 30 ml, by triple-injection technique.

Group H1: Patients in this group received 2% (10 ml) lignocaine and 0.5% (10 ml) bupivacaine plus 0.9% (10 ml) normal saline containing 900 IU (90 IU/ml) hyaluronidase, making a total volume of 30 ml, by triple-injection technique.

Group H2: Patients in this group received 2% (10 ml) lignocaine and 0.5% (10 ml) bupivacaine plus 0.9% (10 ml) normal saline containing 900 IU (90 IU/ml) hyaluronidase, making a total volume of 30 ml, by SI technique.

Lignocaine was used at a dose not exceeding 4 mg/kg. Bupivacaine was used at the dose not exceeding 2 mg/kg. Hyaluronidase concentration (90 IU/ml) was prepared by diluting the vial of hyaluronidase (1500 IU) in 16.5 ml normal saline 0.9%. In all patients, ultrasound-guided nerve blocks were performed using a high-frequency (10–15 MHz) linear probe. After sterilization of the skin, sterile gel was applied for the probe and a 22-G spinal needle was used for injecting the LA solution.

An intravenous drip was started before undertaking the procedure in the contralateral arm, which continued throughout the operation. Vital signs (heart rate, NIBP, oxygen saturation) were observed during the procedure, and oxygen at the rate of 4 l/min was administered to the patients through an oxygen mask.

Techniques of ultrasound-guided supraclavicular brachial plexus block:

Triple injection technique: After skin and transducer preparation, a linear 38 mm, high-frequency 10–15 MHz transducer (SonoScape A5; Shenzhen, China) was placed firmly over the supraclavicular fossa at the midclavicular point in the coronal oblique plane to obtain the best possible transverse view of the subclavian artery and brachial plexus. The patient was supine with the head facing the contralateral side. Nerves in the supraclavicular region appeared hypoechoic and were round or oval. The brachial plexus was located lateral and superficial to the pulsatile subclavian artery and superior to the first rib. The brachial plexus was consistently found lateral and superficial to the subclavian artery and above the first rib. The rib and pleura were identified before needle insertions. Needling was performed following an in-plane approach (lateral to medial). For the in-plane approach, a 22-G spinal needle was inserted under sterile conditions into the outer (lateral) end of the ultrasound transducer after LA infiltration of the skin. The brachial plexus was identified as a compact group of nerves (cluster), present over the first rib, lateral and superficial to the subclavian artery. The needle was advanced along the long axis of the transducer in the same plane as the ultrasound beam. This way, the needle shaft and tip can be visualized in real time as the needle was advanced toward the target nerves. LA solution was injected so as to cause hydrodissection of the planes around the plexus. LA was injected in three aliquots of 10 ml each. Aliquots were deposited in the upper, middle, and lower thirds of the cluster.

SI technique: Using the in-plane needle insertion technique, the needle was advanced from lateral to medial in order to ensure the tip entered the brachial plexus sheath at the most posterior imaged aspect (corner pocket) below the cluster.

Management of unsuccessful block: In the event of inadequate or patchy action of the block, the block was to be supplemented with general anesthesia and this patient would be excluded from the study. If surgery was unduly prolonged and the effect of the block wore off, rescue analgesia with intravenous fentanyl was given. If the pain disappeared, the patient continued being a part of the study.

Monitoring of all parameters was done by an independent anesthesiologist who was not involved in the study.

The following parameters were measured by different anesthesiologists:
  1. Demographic data as regards age, sex, weight, and duration of surgery.
  2. Needling time.
  3. Onset of sensory block: This is defined as the time from injection to complete loss of sensation in each of the major peripheral nerve distributions (ulnar, radial, medial, and musculocutaneous). Sensory block was assessed by pinprick using the blunt end of a 27-G needle at 0, 5, 10, 15, 20, and 30 min. Sensory block was graded according to the following scale: 0=no block (normal sensation); 1=partial block (decreased sensation); and 2=complete block (no sensation) [12].
  4. Onset of motor block: This is defined as the time from injection to the inability of the patient to move his or her fingers or raise his or her hand. Motor block was measured at 0, 5, 10, 20, and 30 min by assessing the following motor functions: flexion at the elbow (musculocutaneous nerve), extension of the elbow and the wrist (radial nerve), opposition of the thumb and index finger (median nerve), and opposition of the thumb and small finger (ulnar nerve). Motor block was graded as follows: 0=no block (full muscle activity); 1=partial block (decreased muscle activity); and 2=complete block (no muscle activity) [12].
  5. Total dose of intraoperative rescue analgesics.
  6. Rate of success of the block.
  7. Duration of sensory block: This is defined as the duration from complete loss of sensation until the patient starts to complain of discomfort or pain as assessed on a 0–10 Visual Analogue Scale (VAS) (VAS>3). During the procedure, anesthesia was considered satisfactory if the patient did not complain of any pain or discomfort. Postoperative follow-up was carried out in the recovery and postoperative ward. Postoperative assessment of pain was done every half an hour for the first 10 h and then hourly for 12 h. Patients were instructed to call for analgesia at any time during the first 24 h postoperatively whenever they were in need. They were then given increments of 2 mg morphine sulfate intravenously each time, for a maximum of 10 mg.
  8. Duration of motor block: This is defined as the duration from the total inability of the patient to move his or her fingers or to raise his or her hand (motor scale=2) until the patient starts to partially move them (motor scale=1). The duration of motor block was assessed every hour by asking the patients to move their fingers and checking whether they are able to raise their hand. This time was recorded and taken as cessation of motor block effect.
  9. Possible side effects of supraclavicular brachial plexus block: Incidence of Horner’s syndrome, phrenic nerve palsy, pneumothorax, respiratory depression and LA toxicity were recorded.


The above assessments were carried out by the principal investigator who was blinded to the drugs administered in the plexus block.

Statistical analysis

Using PASS 13 for determining the sample size, a group sample size of 29 patients per group was required to achieve 80% power to detect a mean difference of 6.0 min in motor block onset with estimated group SD of 6.0 (F-test significance level=0.05000). The size of the variation in the means is represented by their SD, which was 3.40. The common SD within a group was assumed to be 10.00.

Data were analyzed using SPSS 21.0 for Windows (SPSS Inc., Chicago, Illinois, USA). Analysis of variance was used to compare the three groups for quantitative parametric data with post-hoc Tukey’s test performed if there was a significant difference among the groups. The χ2-test was used for comparison of qualitative data. Continuous parametric data were presented as mean±SD, and categorical data as number. P-values less than 0.05 were considered statistically significant.


  Results Top


The demographic data of the three groups are summarized in [Table 1]. Statistical analysis revealed nonsignificant differences between the three study groups as regards age, sex distribution, weight, and duration of surgery. No patient was excluded after inclusion into the study. All patients were able to complete the entire study and their data were included in the final analysis.
Table 1 Demographic data

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The time needed to perform the block was significantly less (4.56±0.57 min) in the H2 group (SI) compared with that in the C group (7.2±0.6 min) and H1 group (TI) (7.3±0.75 min) ([Table 2]). Onset of sensory block was statistically significantly lower in the two groups in which hyaluronidase was used (12.5±1.66 min) compared with that in group C (20.63±2 min) ([Table 2]). Onset of motor block was statistically significantly lower in H1 and H2 groups (13.83±14 min) compared with that in group C (21.6±2 min) ([Table 2]). The mean total intraoperative fentanyl consumption was found to be nonsignificantly higher in group C (76.8±10.7 μg) compared with group H1 (73.73±9.8 μg) and group H2 (73.9±5.06 μg) ([Table 2]).
Table 2 Operative data

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The success of the ultrasound-guided block was tested by recording the number of patients who completed the surgical procedure without using general anesthesia from the start or during the procedure. It was found that only three out of thirty patients in group C could not tolerate the surgery under regional block and even after giving the supplementary fentanyl doses. Those patients needed to be shifted to general anesthesia to complete the surgery. However, in groups H1 and H2 only one out of thirty patients needed to receive general anesthesia ([Table 2]).

As regards the duration of sensory and motor block there was no statistically significant difference between the three studied groups although they were shorter in the two groups in which hyaluronidase was used ([Table 3]).
Table 3 Postoperative data

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The timing of the first analgesic dose was not dependent on the VAS for postoperative pain. Comparison between the three groups revealed nonsignificant differences as regards the time of first analgesic dose. The total dose of morphine given during the first 24 h postoperatively was significantly lower in the control group (10.8±1.186 mg) compared with groups H1 (12.43±1.56 mg) and H2 (12.5±1.4 mg) ([Table 3]).

No side effects or complications occurred in the three studied blocks.


  Discussion Top


In this study addition of hyaluronidase to the LA shortened the onset of sensory and motor block of the ultrasound-guided supraclavicular block. Therefore, the anesthetic time before the start of surgery was reduced. The use of hyaluronidase decreased the duration of the sensory block. The duration of motor block and brachial plexus block analgesia was also reduced, but was not statistically significant. There is advantage in reducing the time to reach complete sensory block as the turnover time between operations can be reduced and operation rooms can be used more efficiently, especially in circumstances in which there is no special area to perform a block [13]. If onset of sensory block is prolonged, supraclavicular block may be harder to justify than general anesthesia, especially for day-case surgeries [4]. As a result, many methods were used to reduce the total time to reach complete sensory block during supraclavicular block. These methods include increasing the injection volume or concentration of LAs, multiple injection techniques, combining different LAs, or adding additives such as dexamethasone, dexmedetomidine, clonidine, and magnesium to the LA. Dexmedetomidine and clonidine as additives to the LA demonstated favorable outcomes in terms of reduced total performance time [14],[15], but most other additives failed to demonstrate any superiority over control.

A previous study reported the effect of the addition of hyaluronidase to bupivacaine 0.5% for axillary brachial plexus blocks [16]. In that study, 3000 IU hyaluronidase mixed with bupivacaine significantly reduced the duration of the sensory and motor block, and had no effect on the number of patients experiencing a complete sensory block after 30 min. In our study we reduced the dose of hyaluronidase to 900 IU mixed with LA. We experienced the same results of reduced duration of sensory and motor block but they were nonsignificant compared with the control group. Also in our study we used ultrasound-guided block, which improved the success rate.

Another study used hyaluronidase as an adjuvant to ropivacaine to reduce axillary brachial plexus block onset time [17]. It also used 3000 IU hyaluronidase mixed with ropivacaine to induce the block. The sensory and motor onsets of the block were reduced significantly compared with the control group. But in our study too we saw the same results; we used two techniques for ultrasound-guided supraclavicular block and found that the SI technique had the same sensory and motor onset as the triple-injection technique with shorter needling time. This result is different from that of a previous study that demonstrated that a TI technique for supraclavicular brachial plexus blockade resulted in improved onset and more complete sensory block at 20 min compared with a SI technique [18].

Hyaluronidase is widely used as an adjuvant to LAs in ocular blocks for ophthalmic surgery, where it can reduce onset time and increase the success rate [19]. Hyaluronidase can also be used for epidural injections with LAs and steroids for control of chronic back pain [20]. The optimal dose of hyaluronidase is not known. In ocular surgeries it varies from 3.75 to 30 IU/ml for successful retrobulbar or peribulbar blocks [19]. For adhesolysis in epidural injection in chronic back pain 1500 IU was used [20]. The most common side effect of hyaluronidase is allergy [21]. It did not happen in this study.


  Conclusion Top


The present study shows that the use of hyaluronidase as an adjuvant to the LA reduces the time to reach complete sensory block of ultrasound-guided supraclavicular brachial plexus blocks and therefore shortens the total anesthetic time before operation. Although it also reduces the block duration, hyaluronidase had only a little effect on the total analgesic duration and on the consumption of postoperative analgesics. Also the SI technique is sufficient for performing a successful block.

Acknowledgements

The authors thank all they colleagues in the Orthopedic Department in Ain Shams and Fayoum University Hospitals for their help in this research.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Williams SR, Chovinard P, Arcand G, Harris P, Ruel M, Boudreault D, Girard F. Ultrasound guidance speeds execution and improves the quality of supraclavicular block. Anesth Analg 2003; 97:1518–1523.  Back to cited text no. 1
    
2.
Neal JM, Gerancher JC, Hebl JR, Lifeld BM, McCartney CJ, Franco CD, Hogan QH. Upper extremity regional anesthesia: essentials of our current understanding, 2008. Reg Anesth Pain Med 2009; 34:134–170.  Back to cited text no. 2
    
3.
Neal JM, Hebl JR, Gerancher JC, Hogan QH. Brachial plexus anesthesia: essentials of our current understanding. Reg Anesth Pain Med 2002; 27:402–428.  Back to cited text no. 3
    
4.
Fredrickson MJ, Patel A, Young S, Chinchanwala S. Speed of onset of ‘corner pocket supraclavicular’ and infraclavicular ultrasound guided brachial plexus block: a randomized observer-blinded comparison. Anaesthesia 2009; 64:738–744.  Back to cited text no. 4
    
5.
Chelly JE. Peripheral nerve blocks a color atlas. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2009.  Back to cited text no. 5
    
6.
Vester-Andersen T, Broby-Johansen U, Bro-Rasmussen F. Perivascular axillary block VI: the distribution of gelatine solution injected into the axillary neurovascular sheath of cadavers. Acta Anaesthesiol Scand 1986; 30:18–22.  Back to cited text no. 6
    
7.
Partridge BL, Katz J, Benirschke K. Functional anatomy of the brachial plexus sheath: implications for anesthesia. Anesthesiology 1987; 66:743–747.  Back to cited text no. 7
    
8.
Dogru K, Duygulu F, Yildiz K, Kotanoglu MS, Madenoglu H, Boyaci A. Hemodynamic and blockade effects of high/low epinephrine doses during axillary brachial plexus blockade with lidocaine 1.5%: a randomized, double-blind study. Reg Anesth Pain Med 2003; 28:401–405.  Back to cited text no. 8
    
9.
McCartney CJ, Duggan E, Apatu E. Should we add clonidine to local anesthetic for peripheral nerve blockade? a qualitative systematic review of the literature. Reg Anesth Pain Med 2007; 32:330–338.  Back to cited text no. 9
    
10.
Choi S, Rodseth R, McCartney CJ. Effects of dexamethasone as a local anesthetic adjuvant for brachial plexus block: a systematic review and meta-analysis of randomized trials. Br J Anaesth 2014; 112:427–439.  Back to cited text no. 10
    
11.
Dunn AL, Heavner JE, Racz G, Day M. Hyaluronidase: a review of approved formulations, indications and off-label use in chronic pain management. Expert Opin Biol Ther 2010; 10:127–131.  Back to cited text no. 11
    
12.
Kathuria S, Gupta S, Dhawan I. Dexmedetomidine as an adjuvant to ropivacaine in supraclavicular brachial plexus block. Saudi J Anaesth 2015; 9:148–154.  Back to cited text no. 12
[PUBMED]  [Full text]  
13.
Minville V, Amathieu R, Luc N, Gris C, Fourcade O, Samil K, Benhamou D. Infraclavicular brachial plexus block versus humeral approach: comparison of anesthetic time and efficacy. Anesth Analg 2005; 101:1198–1201.  Back to cited text no. 13
    
14.
Popping DM, Elia N, Marret E, Wenk M, Tramer MR. Clonidine as an adjuvant to local anesthetics for peripheral nerve and plexus blocks: a meta-analysis of randomized trials. Anesthesiology 2009; 111:406–415.  Back to cited text no. 14
    
15.
Fritsch G, Danninger T, Allerberger K, Tsodikov A, Felder TK, Kapeller M et al. Dexmedetomidine added to ropivacaine extends the duration of interscalene brachial plexus blocks for elective shoulder surgery when compared with ropivacaine alone: a single-center, prospective, triple-blind, randomized controlled trial. Reg Anesth Pain Med 2014; 39:37–47.  Back to cited text no. 15
    
16.
Keeler JF, Simpson KH, Ellis FR, Kay SP. Effect of addition of hyaluronidase to bupivacaine during axillary brachial plexus block. Br J Anaesth 1992; 68:68–71.  Back to cited text no. 16
    
17.
Koh WU, Min HG, Park HS, Karm MH, Lee KK, Yang HS, Ro YJ. Use of hyaluronidase as an adjuvant to ropivacaine to reduce axillary brachial plexus block onset time: a prospective, randomized controlled study. Anaesthesia 2015; 70:282–289.  Back to cited text no. 17
    
18.
Arab SA, Alharbi MK, Nada EM, Alrefai DA, Mowafi HA. Ultrasound-guided supraclavicular brachial plexus block: single versus triple injection technique for upper limb arteriovenous access surgery. Anesth Analg 2014 118:1120–1125.  Back to cited text no. 18
    
19.
Adams L. Adjuvants to local anaesthesia in ophthalmic surgery. Br J Ophthalmol 2011; 95:1345–1349.  Back to cited text no. 19
    
20.
Kim SB, Lee KW, Lee JH, Kim MA, Kim BH. The additional effect of hyaluronidase in lumbar interlaminar epidural injection. Ann Rehabil Med 2011; 35:405–411.  Back to cited text no. 20
    
21.
Kim TW, Lee JH, Yoon KB, Yoon DM. Allergic reactions to hyaluronidase in pain management − a report of three cases. Korean J Anesthesiol 2011; 60:57–59.  Back to cited text no. 21
    



 
 
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