Route of administration of patient controlled analgesia is:
a. Patient controlled analgesia is an automatic system which delivers a fix amount of drug (usually opioids), when patients presses a button by himself.
b. This system is connected to intravenous line (or can also be attached to epidural catheter). A lock out interval is set during which even if patient presses button the drug will not delivered.
c. The advantage of this system is that the psychological component of pain can be avoided (as patient becomes satisfied by pressing the button though no drug is going during lock out period), no delay in decision to medicate and avoidance of painful 1M injection.