Efficacy of intravenous ketamine after spinal anesthesia on post-operative pain

After approval from the institutional ethics committee, study will be conducted in 60 ASA I and ASA II fit patients scheduled for surgeries under spinal anaesthesia aged between 18 to 60 years of age, hemodynamically stable and  with informed consent. 60 patients equally divided into group N and group K in which group N receives normal saline intravenously and group K receives ketamine intravenously. Preoperative pulse, non-invasive blood pressure, ECG and oxygen saturation will be noted. Peripheral venous access will be established and intravenous (IV) fluids will be given, preloading will be with 10ml/kg of Ringer‟s lactate. The spinal anaesthesia will be given in the sitting position with due aseptic precautions. After painting and draping of the lumbar area, 2% xylocaine will be infiltrated in L3-L4 intervertebral space and a 26 G Quincke‟s spinal needle will be introduced. CSF free flow will be confirmed and intrathecal Inj. Bupivicaine 3ml(15mg) will be given. The patient will be placed supine position immediately and will be administered 2 litres of oxygen via a venture mask. Ascent of the sensory block will be checked by pin prick method. Motor blockade will be checked with bromage scale. 10minutes after spinal anaesthesia Inj.Midazolam 1mg will be given followed by study drug

l Group (N) – 30 cases (5ml normal saline intravenously )

l Group (K) – 30 cases (0.25mg/kg of Inj.ketamine diluted upto 5ml with normal saline intravenously)

All the vitals such as heart rate, mean arterial pressure,blood pressure,spo2will be noted at 1min, 5mins and every 10mins after drug injection until the end of surgery

Any other side effects such as tachycardia, bradycardia, hypotension, nausea, vomiting, pruritis, headache will be noted and treated accordingly. Post-operatively visual analogue scale score (VAS) and sedation score will be noted every half hourly.

During the postoperative period, patients will be given Inj. Diclofenac 75mg i.m. stat on demand for rescue analgesia when the pain score is more than 5 on the basis of the Visual Analog Scale. Subsequent rescue analgesics will be given more than 5or more than 5. Time of administration of the rescue analgesic will be noted and chart will be maintained.