Patient Controlled Epidural Analgesia(PCEA) for Post-Operative Pain After Upper Abdominal Surgery, Morphine Vs Combination of Morphine and Midazolam
Dilip Shende, Sudershan T. Lakhe.
Department of Anaesthesia & Intensive Care All India Institute of Medical Sciences, New Delhi (India
Good post-operative analgesia may reduce the incidence of cardiac and pulmonary morbidity in patients undergoing major abdominal and vascular surgery(1).Efficacy of postoperative analgesia by epidural route is well documented.
PCEA is described by many investigators. PCEA has an advantage of patients active participation & lesser dose related side effects
Midazolam alone (2)or in combination with local anaesthetics epidurally has augmented the post-operative analgesia with reduction in requirement of local anaesthetics.
We have planned this double blind RCT to evaluate whether there is any advantage of addition of small dose of midazolam to epidural morphine in PCEA for upper abdominal surgeries.
Aims & Objectives:
To investigate the effect of addition of midazolam 25µg/kg to morphine 50µg/kg in PCEA & assess 1.Analgesia (quality, duration, requirement).2.Incidence & severity of side effects (PONV, Sedation, Respiratory depression, Pruritus).3.Compare two PCEA regimes for above parameters.4.Efficacy, Feasibility of PCEA in our setup. 5.Patient Satisfaction. 6.Anaesthetists view of Analgesia
An anaesthesiologist not participating in the patient care or data collection prepared the drug.
All patients received Standard general anaesthesia using balanced anaesthesia technique. Standard monitoring: ECG, SPO2,NIBP.
Epidural was administered in L2-L3 space, after iv access
Patients were randomly allocated to 2 groups using envelope method in the double blind manner. Drug was given 45 mts. prior to shifting to PACU
Group I received 50µg/kg of morphine in 10 mls of saline
Group II received 50µg/kg morphine and 25µg/kg Midazolam.in 10ml NS
In PACU PCEA device was connected to patient. PCEA Settings were as follows:
GroupI: Morphine 0.2mg/ml,Bolus 1ml with lockout time 10 mts.4h Max.dose4.0mg
Group II:Morphine0.2mg/ml+ Midazolam 100µg/ml solution, Bolus 1ml,lockout 10mts. Max.4hr.dose of Morphine 4.00mg & midazolam 2.0 mg.
Following parameters were noted 0h,1/2h,3,6,9,12,18&24hrs.
Various studies showed good postoperative analgesia reduces the cardiac pulmonary complications as well mortality from these causes. (1). Epidural opioid is very accepted modality but have dose related complications. Allowing patients to control analgesia is important principle in the management of acute pain. The PCEA is particularly useful in treatment of dynamic pain & is observed to use less opioid (3).We used low dose of morphine (0.2mg) but was within recommended range(4).Optimum dose of Midazolam is 50 µg/kg used alone or with bupivacaine(5).We used midazolam 25µg/kg along with morphine to evaluate synergy between clinical efficacies leading to prolongation of morphine action producing morphine sparing effect & reducing the side effects. Our trial was DB,RCT all patients receiving standardized anaesthesia technique. With other parameters constant. Pain was evaluated by VAS.
We conclude that adding low dose of midazolam to morphine PCEA for upper abdominal surgeries enhanced postoperative analgesia, prolonged time for first analgesia(TFA),with Superior VAS scores. Incidence of side effects was similar.