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- Rasha Samir Bondok (15 November 2006)
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intraarticular magnesium sulphate and ketamine; are they analogous?
- RAJESH MAHAJAN, PGIMER CHANDIGARH (3 November 2006)
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Magnesium anaesthesia book
- David J Wilkinson (4 September 2006)
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In response to your letter
- Rasha S Bondok (22 August 2006)
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Strong Magnesium solution.
- Gordon B Drummond (8 August 2006)
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Rasha Samir Bondok, M.D. Lecturer of Anaesthesiology Ain-Shams University
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We would like to thank Dr. Mahajan and colleagues for their interest in our article. In response to your point of view, we did not over enthusiast the analgesic efficacy of intraarticular ketamine rather than mention its analgesic duration in the study by Dal and colleages 109 ± 65 minutes 1 ,which happens to be comparable to your study 102 ± 54 minutes 2, Which still shows the likelihood of ketamine as having a local analgesic effect when applied intraarticularly, Also, prior to our study, intraarticular magnesium was assessed in rats (N. M. El Sharnouby, R. S. Bondok, H. E. Eid, H. F. Fahmy, unpublished data)using a standard preparation of undiluted magnesium sulphate (MgSO4) (10% 1gm/10ml) tested in one knee joint of rat (Magnesium group) and compared to opposite knee joint which was taken as control (Control group). Surprisingly , on histopathological examination at serial time intervals nonsignificant tissue changes (minimal) were observed. In our study on humans, we used half this concentration i.e. 5%. Thank you. 1-Dal D, Tetik O., Al tunkaya H., Tetik O. And Doral M.N. The efficacy of intra-articular ketamine for postoperative analgesia in outpatient arthroscopic surgery Arthroscopy 2004; 20 (3): 300-305 2-Batra YK, Mahajan R, Bangalia SK, Nagi ON, Dhillon MS.. Bupivacaine /ketamine is superior to intraarticular ketamine analgesia following arthroscopy knee surgery. Can J Anesth 2000;38:131-6 6. Conflict of Interest:None declared |
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RAJESH MAHAJAN, doctor , PGIMER CHANDIGARH
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Dear Sir We read with interest the recent article by Bondok and colleagues and accompanying editorial by Durieux in recent issue of BJA regarding the analgesic efficacy of intraarticular magnesium sulphate(MgSO4 ) .1, 2 However we have few points to make. Both Bondok and Durieux have authenticated the analgesic efficacy of intraarticular ketamine , an another NMDA receptor antagonist to corroborate the analgesic efficacy of intraarticular MgSO4 .However we fail to understand the over -enthusiasm with ketamine shown by both the authors, when there are at least three studies which have found that intraarticular ketamine does not confer a clinically significant analgesic effect.3-5 In the study quoted by Bondok and Durieux , Dal and colleagues have found that duration of analgesia conferred by intraarticular ketamine 0.5 mg.kg-1 is approximately 109±65 minutes and is less effective than intraarticular 0.5% bupivacaine which is 120±147 minutes.6 In a similar study, we have demonstrated that a higher dose o(1.0mg.kg-1 )of intraarticular ketamine alone or in combination with bupivacaine does not confers any analgesic benefit..5 The duration of action by intraarticular ketamine was 102±54 minutes in our study and it corroborates with that reported by Dal and colleagues, Huang and colleagues and Rosseland and colleagues .3,,4,6 Both Rosseland and Huang have failed to show any significant analgesic effect of intraarticular ketamine .The duration of analgesic effect of intraarticular ketamine in all these four studies is comparable to that of intraarticular saline (125 min ).7,8 The limited analgesic effect of intraarticular ketamine in all the above studies may be attributable predominantly to local analgesic effect by cooling or diluting intraarticular algogenic substances by injectate saline volume used as a diluent for intraarticular ketamine akin to that observed with intraarticular saline rather than NMDA receptor and opioid receptor interaction .7, 8 Intraarticular bupivacaine has along term safety record of effective intraarticular use after arthroscopic knee surgery .However its analgesic effect has been found to be variable from clinically insignificant from 1 -2 hours to considerably prolonged to 4.6-7 hours in large randomized trials .9-11 This disparity is related to low preoperative pain scores, inadequate number of subjects and lower injectate volume and other confounding factors which significantly influence the duration of analgesic effect by intraarticular analgesic drug . At least initial two confounding factors do exist in Dal’s study. Presently there is emphasis on finding a safe drug for intraarticular use which has analgesic action longer than or can potentiate the effect of intraarticular bupivacaine .Although ketamine has failed on the both the fronts 3-5, Bondok and colleagues need to be applauded for their clinical trial ,making available an effective intraarticular drug with extended duration of analgesia.. Although irritant12, but safe on IV use, this does not assure safety of MgSO4 in localized joint space. MgSO4 solution used by the authors is hypertonic with high concentration of Mg ions and could damage delicate nerve ending and intraarticular structures. Hence an intraarticular trial in animals should have been contemplated before putting it for intraarticular human use. Last but not the least, authors have not demonstrated analgesic efficacy of intraarticular MgSO4 on exercise. Flexing the knee to 90 degrees, the degree pain and adequacy of analgesia are better assessed .Such test has been recommended for postoperative pain, especially when assessing out patients for discharge home and is widely used measure to determine efficacy of intraarticular drugs. . 9, 13, 14 References 1. Bondok RS, EL-Hardy AMA. Intraarticular Magnesium is effective for postoperative analgesia in arthroscopic knee surgery.Br J Anaesth 2006; 97:389-92 2. Durieux ME. Peripheral analgesic receptor system. Br J Anaesth 2006; 97:273-4 3. Huang G, Yeh CC, Kong SS, Lin IC, Ho ST, Wong CS. Intraarticular ketamine for pain control following arthroscopic knee surgery. Acta Anaesthesiol Sin 2000;38;131-6 4. Rosseland LA, Stubhaug A, Sandberg L, Breivik H. intraarticular catheter administration of postoperative analgesics: a new trial design allows evaluation of baseline pain, demonstrates large variance in need of analgesics, and find no analgesic effect of intraarticular ketamine compared with intraarticular saline. Pain 2003;104:25-34 5. Batra YK, Mahajan R, Bangalia SK, Nagi ON, Dhillon MS.. Bupivacaine /ketamine is superior to intraarticular ketamine analgesia following arthroscopy knee surgery. Can J Anesth 2000;38:131-6 6. Dal D, Tetik K, Altukaya H, Tetik O, Doral MN. The efficacy of intraarticular ketamine for postoperative analgesia in outpatient arthroscopic surgery. Arthroscopy 2004; 20:300-5 7. Rosseland LA, Stubhaug A, Grevbo F, et al. Effective pain relief from intraarticular saline with or without morphine 2 mg in patients with moderate to severte pain after knee arthroscopy: a randomized, double- blind controlled clinical study . Acta Anaesthesiol Scand 2003;47:732-8 8. Rosseland LA, Stubhaug A, Skoglund A , Breivik H. intraarticular morphine for pain relief after knee arthroscopic surgery. Acta Anaesthesiol Scand 1999;43:252-57-57 9. Allen GC, St. Amand MA ,Lui ACP, Johnson DH ,Lindsay P. Postarhroscopy analgesia with intraarticular bupivacaine /morphine. Anesthesiology 1993;79:475-80 10. Raja SN, Dickstein RE, Johnson CA. Comparison of postoperative effects of intraarticular bupivacaine and morphine after arthroscopic knee surgery. Anesthesiology 1992;77:1143-47 11. Toivonen J, Pitko VM, Rosenberg PH. Comparison between intraarticular bupivacaine with epinephrine and epinephrine alone on short-term and long -term pain relief after knee arthroscopic knee surgery under general anesthesia in day-surgery patients Acta Anaesthesiol Scand 2002;43:435-40 12. Kelly GH , Cross HC , Turton MR, Hatcher JD .Renal and cardiovascular effects induced by iv infusion of magnesium sulphate.Canad M A D 1960;82:865-71 13. Chapman CR, Syrjala KL. Measurement of pain .in The management of pain .Edited by Bonica J. Philadelphia ,Lea and Febiger 1990.pp580-94 14. Loper KA, Ready LB, Downey M, et al .Epidural and intravenous Fentanyl infusions are clinically equivalent after knee surgery. Anesth Analg 1990 ;70;72-7 Dr Rajesh Mahajan Senior Resident Department of Anaesthesia, PGIMER Chandigarh, India Dr Susheel Kumar Senior Resident Department of Anaesthesia, PGIMER Chandigarh, India Dr Yatendra Kumar Batra Professor Department of Anaesthesia, PGIMER Chandigarh, India Dr M S Dhillon Professor Department of Orthopedics, PGIMER Chandigarh, India Conflict of Interest:NILL |
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David J Wilkinson, Consultant Anaesthetist St Bartholomew's Hospital
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Sir, I was interested to read the article by Bondok et al and the accompanying editorial by Durieux. Both authors describe the peripheral effects of magnesium but fail to cite one of the seminal texts on the use of magnesium written in Copenhagen in 1948. 1. This book details the action of magnesium in a series of elegant animal experiments which tried to determine both central and peripheral actions of the element. It is an interesting document written well before the determination of the NMDA receptor. Although reference to human use of magnesium for anaesthesia is limited it is of great historical significance. 1 Engbaek L. Investigations on the course and localisation of magnesium anesthesia. A comparison with ether anesthesia. Nyt Nordisk Forlag. Arnold Busck, Copenhagen 1948. (Translated from the Danish by Aase Holst) Conflict of Interest:None declared |
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Rasha S Bondok, Lecturer of anaesthesiology Ain Shams University Department of Anaesthesia Cairo
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Thank you for your interest. In reply to your comments: prior to our study, intraarticular magnesium was assessed in rats (as unpublished data)using a standard preparation of undiluted magnesium sulphate (MgSO4) (10% 1gm/10ml) tested in one knee joint of rat (Magnesium group) and compared to opposite knee joint which was taken as control (Control group). Surprisingly , on histopathological examination at serial time intervals nonsignificant tissue changes (minimal) were observed. In our study on humans, we used half this concentration i.e. 5%. Thank you. Conflict of Interest:None declared |
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Gordon B Drummond, Senior Lecturer Edinburgh University
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The pain relief obtained by intra-articular magnesium sulphate after menisecotmy is impressive: but the concentration of magnesium about 200 mMol/litre and the solution is hypertonic. The final concentration in the joint will naturally be affected by the volume of fluid residing after the surgery, and the tonicity of the solution may not be a major issue. However the concentration of Magnesium ions certainly is a problem. These concentrations are well away from normal and I would be concerned that they could cause tissue damage. Have these solutions been tested in animals, and the histological effects assessed? Perhaps the analgesia is a result of permanent nerve damage? I would strongly caution against any medical use of solutions such as these before we can be sure they do not cause damage. Conflict of Interest:None declared |
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