Patients undergoing upper abdominal surgeries are known to experience greater post-operative pain and distress than any other surgery. Pain due to upper abdominal surgeries, apart from being distressing for the patient, also hampers respiration, resulting in a higher post-operative respiratory morbidity. Among various analgesic methods available, epidural analgesia is considered the most effective and has become the routine post-operative pain management for such surgeries. Epidural morphine gives good quality of pain relief, without the hemodynamic instability and motor blockade associated with epidural local anaesthetics. But morphine has its own side effects, like pruritus, nausea, respiratory depression; but all these adverse effects are dose dependent. 

Epidural morphine action is good irrespective of the position of the epidural catheter: Thoracic or Lumbar. Lumbar epidurals give good analgesia even when incision is at thoracic segments since morphine is hydrophilic and spreads rostral. But the incidence of adverse effects is expected to be high. 

While epidural local anesthetics have shown a clear advantage of reduced dose requirement  and consequent reduction in adverse effects when given at concordant levels, the same has not been studied with morphine. Thoracic epidural technique is more challenging when compared to Lumbar epidural due to the difficult anatomy and the potential complications. So a lumbar epidural is preferred if it is possible to give analgesia through this route. But because of the distance to which it has to spread to have the analgesic effect, the dose requirement and consequently the adverse effects are expected to be higher. Administration of morphine at concordant space by reducing the requirement for spread of drug to provide analgesia is expected to reduce the dose requirement and also Thoracic epidural analgesia has shown to decrease perioperative cardiac adverse events and improve pulmonary function post operatively. 

The adverse effects of Morphine can be minimized by using Patient-controlled epidural analgesia (PCEA). PCEA allows patients to take doses as required, thereby reducing the chances of under or overdosing.

 The study aims to assess the quality of  pain relief, amount of Analgesic required and side effect profile of Morphine  through the  use of demand-only PCEA after upper abdominal surgery with the epidural catheter placed at either Thoracic level or Lumbar level.

Although it is clear that lumbar epidural morphine is capable of providing adequate analgesia for upper abdominal surgeries, the difference in dose requirement and adverse effects has not been studied. With PCEA, since patients can take just as much morphine as required, a difference in dose requirement can be observed if present. Previous studies have used a fixed dose intermittent bolus, and so it is not possible to derive if a lesser dose would have been adequate.

Morphine through Thoracic Epidural is expected to provide adequate post-operative pain relief at a lesser dose with lesser side effects than lumbar epidural.

Morphine can be safely used in PCEA through Thoracic epidural route for a pain free post-operative period.

          The hypothesis of this study is "Morphine through Thoracic epidural provides adequate post-operative pain relief with lesser dose and side effects compared to Lumbar epidural in patients undergoing   upper abdominal surgeries".