Ans. A: Prolonged duration of effect Epidural anaesthesia, a form of regional anaesthesia involving injection of drugs through a catheter placed into the epidural space. The injection can cause both a loss of sensation (anaesthesia) and a loss of pain (analgesia), by blocking the transmission of signals through nerves in or near the spinal cord The anaesthetist may use epidural analgesia in addition to general anaesthesia. This may reduce the patient's requirement for opioid analgesics. This is suitable for a wide variety of surgery, for example gynaecological surgery (e.g. hysterectomy), ohopaedic surgery (e.g. hip replacement), general surgery (e.g. laparotomy) and vascular surgery (e.g. open aoic aneurysm repair) which are longer duration surgeries. Other features of epidural anaesthesia: Expensive compared to spinal anaesthesia More incidence of intravascular injection (epidural space has venous plexus of Batson) More incidence of epidural hematoma Level of block can be changed by increasing the dose through the catheter