The surgical interventions for treating morbid obesity, i.e. bypass procedure and sleeve
gastrectomy are collectively covered under the term 'bariatric surgery'. The growth of
bariatric surgery has seen consonant development of anaesthesia techniques so as to ensure
patient safety and facilitate post-surgery outcome. Conventionally, balanced general
anaesthesia techniques routinely use opioids peri-operatively for intra-operative
haemodynamic homeostasis and postoperative pain relief. However, since the morbidly obese
patients have high prevalence of obstructive sleep apnea(OSA) and other co-morbidities the
same technique when employed in the morbidly obese patients hampers early and intermediate
postoperative recovery due to the occurrence of side effects, such as, sedation, PONV,
respiratory depression, depressed GI-mobility. The above stated side effects, have lead to
increased propensity for postoperative cardiac and pulmonary complications. Obese patients
are more vulnerable and sensitive to the narcotics and sedatives, these drugs need to be
employed judiciously in these patients. On the other hand, the reduction in opioid use may
result in acute post-operative pain that may limit post-surgery rehabilitation. Therefore, we
need to minimise opioid use and employ some other drugs which besides having analgesia, has a
opioid-sparing effect also.
Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has analgesic properties in
sub-anaesthetic doses. When used in low dose (0.2mg/kg), it is an analgesic,
anti-hyperalgesic, and prevents development of opioid tolerance. On a conceptual basis, a key
advantage of ketamine is that it can reduces post-operative pain and use of opioid when used
per-operatively. Therefore, a regimen which avoid or minimise use of opioid is likely to
decrease opioid-related postoperative morbidity in these patients undergoing bariatric
surgery.In view of the above, a clinical research is highly desirable to study techniques to
decrease the use of opioids in obese surgical patients.This prospective randomised two-arm
study aims to assess the effect of low-dose ketamine on postoperative pain relief and
opioid-sparing ability in obese patients undergoing bariatric surgery.