Obesity-Related Challenges in Interventional Pain Management

Educational Objectives

The goal of this program is to improve management of pain in patients with obesity. After hearing and assimilating this program, the clinician will be better able to:

1. Modify techniques of interventional pain management for patients with obesity.
2. Administer nonsurgical treatments for musculoskeletal pain.

Summary

Radiologic considerations: equipment may not be able to accommodate larger patients; radiation exposure for the patient and staff is higher; the C-arm produces a higher brightness level for patients with obesity; longer needles may be needed; procedure time may be 30% longer and time under x-ray is 35% longer in patients with obesity compared with nonobese patients; the dose of entry site radiation is 10-fold higher for patients with obesity compared with nonobese patients; technicians should consider scatter angle and distance from the patient to protect themselves

Considerations for surgery: the primary cause of negative outcomes during pain procedures is oversedation, according to the American Society of Anesthesiologists Closed Claims Database; hypoventilation is a concern for patients in the prone position; the bed may be adjusted or the patient supported with pillows; sedation should be administered in the operating room with the anesthesia care team present; the physician may continually monitor the patient while other staff performs procedures

Anatomical considerations: patients with obesity are at a high risk for spinal epidural lipomatosis, which may cause spinal stenosis; incidence increases with increase in body mass index (BMI) and number of epidurals administered

Comorbidities: many procedures involve the use of steroids; blood glucose should be monitored for ≥2 days prior to a procedure and ≥5 days after, according to guidelines from the International Spine Society; epidural steroid injections may cause blood glucose and insulin resistance to increase; the intensity of the effect depends on dosing and frequency of administration; steroid-sparing approaches should be considered (eg, medial branch block); patients with blood glucose >220 mg/dL and A_1c of >7.2% may have surgery postponed; there are no specific guidelines for hypertension; steroids may increase systolic blood pressure by 5 mmHg to 10 mmHg, which is significant in patients whose hypertension is not well controlled; prone positioning and nerve blocks may increase blood pressure

Pain and obesity: 35% of persons in the United States are obese; proinflammatory conditions (eg, hypertension, hyperlipidemia, asthma, arthritis) are more common in patients with obesity; Stone et al (2012) found that a patient’s BMI is associated with pain; patients who are morbidly obese are 4 times more likely to have back pain; patients with obesity have higher rates of, eg, neuropathic pain, musculoskeletal pain, headache, fibromyalgia, postoperative pain

Neuropathic pain: obesity is associated with lower pain thresholds and higher reported intensity of pain, as measured by electrophysiological testing, pressure testing, and temperature testing; local neuropathic conditions are more common in patients with obesity, eg, carpal tunnel syndrome, cubital tunnel syndrome, meralgia paresthetica; the incidence of meralgia paresthetica is 2 times higher in patients with obesity; non-weight bearing joints are 2 times more likely to be affected (eg, carpal tunnel syndrome); a high level of visceral fat is associated with increased rates of neuropathic conditions, in particular small-fiber neuropathies; diabetic peripheral neuropathy is common in patients with obesity; levels of inflammatory markers in patients with fibromyalgia increase as BMI increases; pain induced by fibromyalgia limits activity, which causes weight gain; weight gain produces greater levels of inflammatory markers increase which disrupt the sleep cycle; disrupted sleep may produce increased hunger and further weight gain

Headaches and obesity: the risk for chronic daily headache increases by 35% in patients who are overweight; the risk increases to 80% for a BMI ≥40; idiopathic intracranial hypertension and headache related to sleep apnea are commonly seen in patients with obesity; migraines are twice as likely to occur in patients with obesity; the probability of episodic migraine turning into chronic daily headache is increased; levels of the inflammatory chemical calcitonin gene-related peptide are elevated in patients with obesity

Musculoskeletal pain: mostly derived from mechanical loading of joints; patients with obesity have longer surgery times, longer recovery, and increased risk of infection; opioids are more often required for pain management, and at higher doses, compared with nonobese patients; metabolic issues (eg, hyperlipidemia) increase the risk for osteoarthritis in the knees and hip; statins may protect against osteoarthritis; patients with obesity are more likely to have tendinopathies (eg, rotator cuff issues, tennis elbow, golfer’s elbow); increased inflammatory response causes local tendon irritation; Chin et al (2020) found loading of lumbar discs exceeded recommended levels when patients with obesity lifted negligible amounts of weight

Pain management: patients may be too obese to undergo surgery to address joint issues; weight loss through diet, lifestyle modifications, or bariatric surgery should be discussed; smoking cessation should be discussed; persons with BMI >40 are normally not recommended to undergo joint replacement surgery

Possible alternatives to surgery: nerve blocks may be given to patients who cannot undergo surgery; obturator and femoral nerve blocks may be given for hip pain; a suprascapular nerve block may be given for shoulder pain; a genicular nerve block may be given for knee pain; the genicular nerves are sensory-only branches of the femoral nerve; blocking them does not cause loss of skin sensation or motor sensation; the superior medial, superior lateral, and inferior medial genicular nerves may be blocked; nerve blocks may provide pain relief for ≤6 mo; radiofrequency ablation is an evolving field; the goal is to achieve mobility; research on peripheral nerve stimulation is ongoing; a stimulator is implanted in place of a catheter on the nerve endings which are targeted; often placed at the femoral nerve level or adductor canal level; treatment decisions are individualized

Readings

Callaghan BC, Gao L, Li Y, et al. Diabetes and obesity are the main metabolic drivers of peripheral neuropathy. Ann Clin Transl Neurol. 2018;5(4):397-405. Published 2018 Feb 14. doi:10.1002/acn3.531; Chin SH, Huang WL, Akter S, Binks M. Obesity and pain: a systematic review. Int J Obes (Lond). 2020;44(5):969-979. doi:10.1038/s41366-019-0505-y; Holder EK, Raju R, Dundas MA, et al. Is there an association between lumbosacral epidural lipomatosis and lumbosacral epidural steroid injections? A comprehensive narrative literature review. N Am Spine Soc J. 2022;9(100101):100101. doi:10.1016/j.xnsj.2022.100101; Jamison DE, Cohen SP. Radiofrequency techniques to treat chronic knee pain: a comprehensive review of anatomy, effectiveness, treatment parameters, and patient selection. J Pain Res. 2018;11:1879-1888. Published 2018 Sep 18. doi:10.2147/JPR.S144633; Kim K, Mendelis J, Cho W. Spinal Epidural lipomatosis: a review of pathogenesis, characteristics, clinical presentation, and management. Global Spine J. 2019;9(6):658-665. doi:10.1177/2192568218793617; Nukala S, Puvvada SR, Luvsannyam E, Patel D, Hamid P. Hyperlipidemia and statin use on the progression of osteoarthritis: a systematic review. Cureus. 2021;13(6):e15999. Published 2021 Jun 28. doi:10.7759/cureus.15999; Okifuji A, Hare BD. The association between chronic pain and obesity. J Pain Res. 2015;8:399-408. Published 2015 Jul 14. doi:10.2147/JPR.S55598; Reeves RA, Hefter GD, Pellegrini VD Jr, Drew JM, Barfield WR, Demos HA. The fate of morbidly obese patients with joint pain: a retrospective study of patient outcomes. J Arthroplasty. 2021;36(9):3101-3107.e1. doi:10.1016/j.arth.2021.02.069; Smuck M, Kao MC, Brar N, et al. Does physical activity influence the relationship between low back pain and obesity?. Spine J. 2014;14(2):209-216. doi:10.1016/j.spinee.2013.11.010; Stokes A, Berry KM, Collins JM, et al. The contribution of obesity to prescription opioid use in the United States. Pain. 2019;160(10):2255-2262. doi:10.1097/j.pain.0000000000001612; Uppot RN. Technical challenges of imaging & image-guided interventions in obese patients. Br J Radiol. Published online 2018:20170931. doi:10.1259/bjr.20170931; Yeh T, Beutler SS, Urman RD. What we can learn from nonoperating room anesthesia registries: analysis of clinical outcomes and closed claims data: analysis of closed claims liability data. Curr Opin Anaesthesiol. 2020;33(4):527-532. doi:10.1097/aco.0000000000000844.

Disclosures

For this program, members of the faculty and planning committee reported nothing relevant to disclose.

Acknowledgements

Dr. Lankhorst was recorded at the 69th Annual Convention and Conclave of the American Osteopathic College of Anesthesiologists, held September 25-28, 2021, in Palm Beach, FL, and presented by the American Osteopathic College of Anesthesiologists. For information about CME activities from this presenter, please visit www.aocaonline.org. Audio Digest thanks the speakers and presenters for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 1.00 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 1.00 CE contact hours.

Lecture ID:

AN644801

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.

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