|LETTER TO EDITOR
|Year : 2016 | Volume
| Issue : 2 | Page : 314-315
Intrathecal ketamine as an adjuvant in day-case surgeries: Comments
Mohd Saif Khan MD, DNB, PDFCC
Division of Critical Care, Department of Anaesthesia, Critical Care and Pain, Tata Memorial Hospital, Parel, Mumbai, India
|Date of Submission||23-Feb-2015|
|Date of Acceptance||05-Apr-2016|
|Date of Web Publication||11-May-2016|
Mohd Saif Khan
No. 3-A, D Block, PIMS Staff Quarters, Kalapet, Puducherry 605014
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Khan MS. Intrathecal ketamine as an adjuvant in day-case surgeries: Comments. Ain-Shams J Anaesthesiol 2016;9:314-5
It was, indeed, a pleasure to read the article on intrathecal ketamine published in your esteemed journal by Kamal et al. . Authors did a commendable job in carrying out this research. The findings from this study may be useful for those involved in the practice of ambulatory anesthesia. Investigators used 15 mg of heavy bupivacaine in one arm and 10 mg of heavy bupivacaine plus 25 mg of ketamine intrathecally in the other. The study concluded that ketamine added to hyperbaric bupivacaine in subarachnoid block (SAB) provides a shorter time of onset of block as well as shorter duration of motor block.
However, it is worth mentioning here that there is a significant difference in dosages of bupivacaine used in the two arms, which could itself lead to a shorter duration of block. Therefore, the results of this study should be carefully interpreted before drawing any conclusion regarding the effect of ketamine on total duration of SAB. Considering this as bias, another study may be planned in future comparing three groups - two groups similar to this study and another group receiving 10 mg of heavy bupivacaine and 1 ml of normal saline intrathecally. Nevertheless, it is agreeable that ketamine does shorten the onset of motor block, as previously described by many other investigators .
Another point toward which I would like to draw attention is the duration of postoperative analgesia, which can be achieved by adding adjuvants to intrathecal bupivacaine. In this regard, it is better to infer from the study that ketamine failed to provide any advantage to the patient. Rather, as per the study, ketamine decreased the total duration of spinal analgesia when compared with bupivacaine alone. Here again, we must consider the fact that comparatively reduced dose of bupivacaine (10 mg) could be the reason for this effect. Ketamine shows analgesic property owing to its antagonistic action on N-methyl-d-aspartate receptors in the spinal dorsal horn . One study reported prolongation of postoperative analgesia when ketamine was added to intrathecal bupivacaine in nonpregnant patients undergoing lower abdominal and lower limb surgeries . There is another prospective trial that evaluated the effect of intrathecal ketamine and midazolam on postoperative analgesia in 60 patients undergoing orthopedic surgery and concluded that the low dose of midazolam and ketamine with bupivacaine intrathecally results in prolonged analgesia and less hemodynamic fluctuations .
Readers might also be interested to know the types of surgeries carried out in these patients, whether they were infraumbilical or supraumbilical procedures. This information may be crucial for those who are interested in performing the supraumbilical procedures (such as lipoma excision or incisional hernia repair) in ambulatory settings. There is no information regarding the height of SAB achieved in either group so that a reduced dose of bupivacaine just enough to achieve necessary level of SAB can be studied in the future.
In first paragraph of page 531, it is mentioned that 'The onset time of motor block was measured from the time of epidural injection till the modified Bromage score was 3.' Did investigators also use epidural anesthesia? This might be presumed as a printing error.
Special thanks to my wife Dr Tahmina S., Assistant Professor, Department of Obstetrics and Gynecology for critical appraisal of manuscript and valuable suggestions.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Kamal MM, El-Fawy D. The effect of adding ketamine to bupivacaine in spinal anesthesia in day-case surgery. Ain-Shams J Anaesthesiol 2014; 7:530-533.
Kathirvel S, Sadhasivam S, Saxena A, Kannan TR, Ganjoo P. Effects of intrathecal ketamine added to bupivacaine for spinal anaesthesia. Anaesthesia 2000; 55:899-904.
Weinbroum AA. A single small dose of postoperative ketamine provides rapid and sustained improvement in morphine analgesia in the presence of morphine-resistant pain. Anesth Analg 2003; 96:789-795.
Hemanth N, Geetha S, Aloka S, Rao MH, Madhusudan M. A comparative study of intrathecal ketamine as an additive to 0.5% hyperbaric bupivacaine for intrathecal anaesthesia. J Clin Sci Res 2013; 2:197-202.
Murali Krishna T, Panda NB, Batra YK, Rajeev S. Combination of low doses of intrathecal ketamine and midazolam with bupivacaine improves postoperative analgesia in orthopaedic surgery. Eur J Anaesthesiol 2008; 25:299-306.