Intrathecally Administered Ketamine, Dexmedetomidine, and Their Combination With Bupivacaine for Postoperative Analgesia in Major Abdominal Cancer Surgery
Description:
This study was approved by the ethics committee of South Egypt Cancer Institute, Assiut
University, Assiut, Egypt. After obtaining a written informed consent, 90 American Society of
Anesthesia (ASA) I-II patients aged 30-50 years and scheduled for major abdominal cancer
surgery were included in the study. Patients with a known allergy to the study drugs,
significant cardiac, respiratory, renal or hepatic disease, coagulation disorder, infection
at the site of intrathecal injection, drug or alcohol abuse, BMI > 30 kg/m2 , and psychiatric
illnesses that would interfere with perception and assessment of pain were excluded from the
study.
Preoperatively, patients were taught how to evaluate their own pain intensity using the
visual analogue scale (VAS), scored from 0 -10 (where 0 = no pain, and 10 = the worst pain
imaginable).
Oral diazepam (5 mg) was taken the night before surgery. Up on arrival at the operative
theatre, a 16-gauge catheter was introduced intravenously at the dorsum of the hand; lactated
Ringer’s solution 10 mg/kg was infused intravenously over 10 min. before initiation of spinal
anesthesia. Basic monitoring probes (electrocardiography, non invasive blood pressure, O2
saturation, and temperature) were applied. Patients were placed in the setting position and a
25-gauge Quincke needle was placed in the L2-3 or L3-4 interspaces.
Patients were randomly divided, by selecting sealed envelopes into one of three groups 30
patients each:
– The dexmedetomidine group (group I) received 10 mg of hyperbaric bupivacaine 0.5% in 2
ml volume and 5µg of dexmedetomidine in 1 ml volume intrathecally.
– The ketamine group (group II) received 10 mg of hyperbaric bupivacaine 0.5% in 2 ml
volume and 0.1 mg/kg ketamine in 1ml volume intrathecally.
– Dexmedetomidine + Ketamine group (group III) received 10 mg of hyperbaric bupivacaine
0.5% in 2 ml volume and 5µg of dexmedetomidine plus 0.1 mg/kg of Ketamine in 1 ml volume
intrathecally.
Immediately after their intrathecal injection, the patients were placed in the supine
position. After successful spinal anesthesia, general anesthesia was induced with fentanyl
1.5-2 µg/kg, propofol 2-3 mg/kg, and lidocaine 1.5 mg/kg. Endotracheal intubation was
facilitated by cis-atracurium 0.15 mg/kg. Heart rate, systolic, and diastolic blood pressure
were recorded at 5, 10, 20, 30, 60, 120, 180 minutes. Anesthesia and muscle relaxation were
maintained by isoflurane 1- 1.5 MAC in 50% oxygen/air mixture and cis-atracurium 0.03 mg/kg
bolus given every 30 min. respectively.
At the end of surgery, muscle relaxation was reversed by neostigmine 50 µg/kg and atropine 20
µg/kg. Patients were extubated and transferred to postanesthesia care unit (PACU) and were
monitored for vital signs (heart rate, non invasive blood pressure, respiratory rate, and O2
saturation) immediately postoperative and at 2, 4, 6, 12, 18, and 24 hours postoperative.
VAS scores were assessed at the same time points. Rescue analgesia represented by
patient-controlled analgesia (PCA) with intravenous morphine with an initial bolus of 0.1
mg/kg once pain was expressed by the patient, or if VAS was 3 or more (VAS ≥ 3) followed by 1
mg boluses with a lockout period of 5 min. The time of first request of analgesia and total
analgesic consumption in the first 24 hours postoperatively were recorded.
The patient’s level of sedation was assessed at the same time points using a modified
Observer’s Assessment of alertness/sedation (OAAS) scale (where 6 = agitated, and 0 = doesn’t
respond to deep stimuls).
The attendant anesthesiologist, the patient-care giver, and the data collection personnel
were all blinded to patient assignment to a specific group. Postoperative adverse effects
such as nausea, vomiting, hypotension, bradycardia, cardiac arrhythmias were recorded and
treated.
Hypotension was defined as a 15% decrease in systolic blood pressure from baseline.
Bradycardia was defined as a heart rate slower than 50 beats per minute or a decrease in
heart rate of 20% or more from baseline; whichever is lowest. Hypoxia was defined as an
oxygen saturation of less than 90%. Hypotension was treated with intravenous boluse of
ephidrine 0.1 mg/kg and normal saline 5ml/kg; the same doses were repeated as required.
Bradycardia was treated with intravenous atropine 0.01 mg/kg.
Condition:
Therapy
Treatment:
intrathecal drug administration
Start Date:
March 2015
Sponsor:
Assiut University
For More Information:
https://clinicaltrials.gov/show/NCT02455609