Page 24 - CASA Bulletin of Anesthesiologisy 2022 9(6)-1 (3)

CASA Bulletin of Anesthesiology

Multimodal Analgesia for Complex Spine Surgeries

Ye Rin Koh MD, Mariel Manlapaz MD, Ehab Farag MD FRCA FASA

Postoperative pain following complex spine surgery is particularly a major challenge for
anesthesiologists due to the combination of extensive tissue trauma (from muscle dissection &
surgical manipulation at the operative site) and the patient population who already have
significant spine pain at baseline. Up to 55% of spine surgery patients struggle with chronic pain
preoperatively and as many as 50% of patients are already consuming regular opioids at the time
of surgery. As expected, preoperative opioid use is directly related to postoperative opioid use as
well as other complications including increased hospital length of stay, healthcare costs, risk of
surgical revision and hospital readmission within 90 days 1, 2, 3 . Severe postoperative pain can
delay postoperative recovery and prolong rehabilitation. Lumbar fusion and large spinal
reconstruction procedures represented the top six surgeries with the highest pain scores on the
first postoperative day and 3-34% patients undergoing single-level discectomy without
instrumentation experienced persistent pain in the short term (6-24 months) and 5-36% in the
4, 5
long term (> 24 months) postoperative period .

Postoperative pain following spine surgeries are also at high risk for progressing into chronic
pain, with its frequency ranging from 5% to 75% . In another study, it was shown that 7.2% of
6, 7
patients experience persistent low back pain following posterior decompression & instrumented
fusion surgery. The risk factors for developing this included preoperative low back pain, surgery
on the spinal segments L5-S1, and preoperative paraspinal muscle degeneration . Chronic
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postsurgical pain (CPSP), which is defined as persistent post-surgical pain lasting longer than 2
months, is a complication that can lead to unexpected functional limitations and immense
psychological distress. Unlike acute postoperative surgical pain which is primarily somatic and
visceral, CPSP has a neuropathic component that is more difficult to treat. It is therefore
important to identify the risk factors and develop preventative strategies to reduce the risk of
developing CPSP as much as possible. The risk factors for developing CPSP includes
preoperative pain, psychological factors (ie. anxiety), surgical site, surgical duration (greater than
3 hours), female sex and younger age. Most importantly, severe acute postoperative pain has
been shown to be associated with an increased risk of developing CPSP, emphasizing the
importance of adequate postoperative pain control in this population .
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Prior investigations have shown that postoperative pain following spine surgery may involve
a combination of pathways including neuropathic, inflammatory, and nociceptive pain responses
10 . In acute pain, previous studies have evaluated the role of PGE-2 and IL-6 in the induction of
pain and inflammation . In addition, activation N-Methyl-D-aspartate (NMDA) receptors and
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central sensitization with associated secondary hyperalgesia have been implicated in the
development of chronic pain . The growing body of evidence indicates that the combination of
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pharmacologic agents that simultaneously act upon multiple pain pathways can provide a
synergistic effect while reducing the need for each medication and its potential side effects.

NSAIDs & COX-2 inhibitors

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