I was reminded the other night of what a tremendous benefit local anesthesia techniques offer my patients.  I got called in to anesthetize a 5-year-old Australian Cattle Dog for an emergency Caesarean section.  Normally, my patients receive high-quality preemptive analgesia in the form of a systemically acting mu opioid.  For c-sections, however, in order to improve the chances of a positive outcome for the puppies, I do not follow this normal protocol.  Rather, I will perform a pre-incisional local line block with lidocaine and bupivacaine/epinephrine, and, ideally, a lumbosacral epidural with preservative-free morphine and bupivacaine.  Once the puppies have been removed, I give an IV opioid (usually nalbuphine) and, if not contraindicated, SQ Rimadyl to mom.

Unfortunately, I don’t always have approval to perform the epidural.  Perhaps the supervising veterinarian has not discussed the advantages/disadvantages/added cost with the client before s/he left the building.  Perhaps that discussion was held, but the client did not approve the procedure.  Perhaps the veterinarian is reluctant to add time spent under gas anesthesia, which poses an increased risk to both mom and the puppies.

In this case, the epidural was approved.  Mom was induced with propofol and placed into dorsal recumbency to clip her abdomen (she was anxious and would not tolerate clipping while awake).  I then aseptically prepped an area along midline and performed the preincisional line block.  Mom was then rolled into lateral recumbency and I clipped and aseptically prepped an area over the lumbosacral junction and then administered 0.1 mg/kg each of preservative-free morphine and bupivacaine (no epinephrine) into the epidural space, using a loss-of-resistance syringe to confirm spinal needle placement prior to drug injection.  Total added gas anesthetic time to perform the epidural?  Two minutes!

Without an epidural, these patients are usually on an anesthetic roller coaster, becoming light and requiring higher inhalant concentrations and repeated IV boluses of propofol.  Blood pressures fluctuate wildly.  Once the puppies are out and I give an IV opioid, the anesthesia maintenance is much smoother.

My patient the other night was much better managed with the epidural on board.  She required no additional boluses of propofol; mean arterial blood pressure (MAP) readings after the epidural ranged between 75 and 85 mmHg; sevoflurane concentration was maintained at 2-2.5% in 100% oxygen throughout the procedure.  She did receive a 0.5 mg/kg IV dose of nalbuphine and 4 mg/kg SQ injection of Rimadyl once the puppies were taken out  (the one viable puppy was crying for his momma within a couple of minutes after he was removed!).  At the end of the procedure, I continued supplemental oxygen via the ET tube and extubated her 10 minutes after turning her gas off.  Recovery was smooth and uneventful.

Local anesthesia techniques provide outstanding analgesic support (helping to prevent wind-up), and they also result in lower maintenance drug requirements, thereby reducing the effects of unwanted side effects such as hypotension.  For c-sections, using less gas and injectable anesthetics can mean the difference between life and death for the puppies!