Chapter 71: Multimodal Analgesia: Pharmacologic Interventions and Prevention of Persistent Postoperative Pain

Chapter 71. Multimodal Analgesia: Pharmacologic Interventions and Prevention of Persistent Postoperative Pain

A 36-year-old woman with history of Crohn’s disease is complaining of pain in the post-anesthesia recovery unit following ileocecal resection for small bowel obstruction. Which agent would be most appropriate to treat her pain symptoms?

A. Oral hydrocodone/acetaminophen 10/325 mg

B. Rectal acetaminophen 650 mg

C. Intravenous acetaminophen 1000 mg

D. Intravenous ketorolac 30 mg

C is correct. Intravenous acetaminophen has a rapid time to meaningful analgesia less than 30 minutes following administration.

A, B, and D are incorrect. An intravenous medication would be appropriate following abdominal surgery. NSAIDs can increase the risk of anastomotic leak and would best be avoided.

When combined with acetaminophen, which of the following substances has been proven to have a synergistic effect?

A. Gabapentin

B. Lidocaine

C. Ketamine

D. Ibuprofen

D is correct. The synergism between nonsteroidal antiinflammatory agents and acetaminophen is well-described.

A, B, and C are incorrect. There is no such description of synergism between local anesthetics, anticonvulsants, or ketamine with NSAIDs.

Nociceptor sensitization occurs following tissue damage and cyclooxygenase (COX) production of which ligand?

A. Prostaglandins (PEs) PGE₁ and PGE₂

B. Histamine and bradykinin

C. Substance P

D. Calcitonin gene-related peptide

A is correct. PGE₁ and PGE₂ are the byproducts of cell membrane metabolism by cyclooxygenase. They are responsible for sensitizing nociceptors to painful and nonpainful stimuli.

B is incorrect. Bradykinin is an inflammatory mediator involved in pain signaling and can cause vasodilation. Histamine is a molecule that acts as a neurotransmitter in the central nervous system and peripherally it is involved in a number of other physiologic processes.

C is incorrect. Substance P is an excitatory neurotransmitter involved in the transmission of signals; it is thought to be one of the first chemicals released in response to pain.

D is incorrect. Calcitonin gene-related peptide is released in the dorsal horn of the spinal cord and is involved in the pain pathway.

Despite escalating the dose of gabapentin from 300 mg three times daily to 600 mg three times daily, a 56-year-old man fails ...