Complex sentence: Common agents are hydromorphone or a weak local anesthetic and an opiate.Initiallt this technique was indicated for caesarian section, high risk orthopaedic surgery (to avoid spinal induced hypotension).
Split into simpler sentences: Common agents are hydromorphone or a weak local anesthetic and an opiate. Initially this technique was indicated for caesarian section, high risk orthopaedic surgery (to avoid spinal induced hypotension).