Treatment of Psychosomatic Pain in the Emergency Department with Sub-dissociative Dose Ketamine
…administered 8 mg of ketamine (0.15 mg/kg) in 400 mL of normal saline over 15 minutes…marked improvement in both pain and anxiety…
introduction
Psychosomatic pain is a common Emergency Department (ED) complaint that may often frustrate both patients and providers. While patients struggle to find relief, providers may struggle to produce it using conventional modalities available in the ED. Significant functional impairment may be present, prompting high resource utilization, increased costs, and inappropriate medical investigations. Misdiagnosis is common, and no clinical guidelines currently exist for the optimal ED management of psychosomatic pain. [1]
The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), defines somatic symptom disorder (SSD) as a condition in which the patient’s subjective reporting of physical symptoms is associated with distress, disruption of daily functioning, and disproportionate thoughts, feelings, and behaviors related to those symptoms. [2]
SSD is not a diagnosis of exclusion, but rather a positive diagnosis that should be made as early as possible to limit iatrogenic harm. Although no formal management guidelines have been developed, the literature suggests that early psychiatric intervention is associated with significant improvement in patient functioning and somatic symptoms, as well as a reduction in healthcare costs [3] and depressive symptoms. [4] Antidepressants may be initiated. Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) have shown efficacy in improving SSD compared to placebo. [5] However, many emergency providers are reluctant to initiate such medications in the absence of ongoing clinical follow-up.
Ketamine may offer a viable alternative for treating refractory psychosomatic pain in the ED. We present a case below. To our knowledge, this is the first documented case of psychosomatic pain successfully treated with ketamine in the ED.
case
A 45-year-old female with a past medical history significant for Hashimoto’s thyroiditis, depression, post-traumatic stress disorder, scleroderma, shingles, and herpes simplex virus presented to the ED with chief complaints of left-sided neck pain and headache. The patient reported that her symptoms began after an interstate car ride during which her child was driving, leaving her feeling anxious. She denied any acute neurologic deficits, red-flag symptoms for headache, chest pain, shortness of breath, and abdominal pain. She was afebrile during the encounter. Her Glasgow Coma Scale (GCS) was 15, and she was alert and oriented. Physical examination was notable for multiple areas of point tenderness over the left trapezius muscle. She denied photophobia but endorsed a history of migraines. Computed tomography angiography of the brain and neck revealed no abnormalities.
The patient received 1000 mL of lactated Ringer’s solution, acetaminophen 975 mg, diphenhydramine 25 mg, prochlorperazine 10 mg, diazepam 10 mg, and a 4% lidocaine patch. She was observed in the ED without improvement. On re-evaluation, the patient continued to express anxiety related to her child learning to drive. She also endorsed ongoing depressive symptoms and reported being unengaged in psychiatric care.
The patient was then administered 8 mg of ketamine (0.15 mg/kg) in 400 mL of normal saline over 15 minutes. Following this treatment, she reported marked improvement in both pain and anxiety. She was discharged with primary care follow-up, as well as prescriptions for cyclobenzaprine 10 mg and 4% lidocaine patches as needed.
discussion
Ketamine may have been successful in this case because psychosomatic pain is often mediated by underlying depression, though the exact mechanism remains an area of active research. Recent studies support the assertion that antidepressants are efficacious in alleviating somatic pain. [5] Additionally, small case series have shown that sub-psychedelic doses of psilocybin (a serotonergic compound) may reduce chronic pain scores and reliance on traditional pain management modalities. [6]
It is possible that ketamine was effective here due to its role as a rapid-acting antidepressant. Ketamine exerts a rapid effect on depressive symptoms. [7] Its antidepressant properties distinguish it from other common pain therapies and may suggest a unique clinical utility in treating psychosomatic pain. Large randomized controlled trials are needed to further evaluate the role of ketamine in ED management of psychosomatic pain.
AUTHOR: Dr. Keaton Cameron-Burr is a fourth year emergency medicine resident at Brown Emergency Medicine Residency.
FACULTY REVIEWER: Dr. Kristina McAteer is an assistant professor/clinician educator at Brown Emergency Medicine.
references
1) Cozzi G, Lucarelli A, Borrometi F, Corsini I, Passone E, Pusceddu S, Morabito G, Barbi E, Benini F. How to recognize and manage psychosomatic pain in the pediatric emergency department. Ital J Pediatr. 2021 Mar 25;47(1):74.
2) American Psychiatric Association . Somatic Symptom and related disorders. In: American Psychiatric Association, editor. Diagnostic and Statistical Manual of Mental Disorders. 5. Arlington: American Psychiatric Publishing; 2013. pp. 318–321.
3) Allen LA, Woolfolk RL, Escobar JI, Gara MA, Hamer RM. Cognitive-behavioral therapy for somatization disorder: a randomized controlled trial. Arch Intern Med. 2006 Jul 24;166(14):1512-8.
4) Beltman MW, Voshaar RC, Speckens AE. Cognitive-behavioural therapy for depression in people with a somatic disease: meta-analysis of randomised controlled trials. Br J Psychiatry. 2010 Jul;197(1):11-9.
5) Kleinstäuber M, Witthöft M, Steffanowski A, van Marwijk H, Hiller W, Lambert MJ. Pharmacological interventions for somatoform disorders in adults. Cochrane Database Syst Rev. 2014 Nov 07;2014(11):CD010628.
6) Lyes M, Yang KH, Castellanos J, Furnish T. Microdosing psilocybin for chronic pain: a case series. Pain. 2023 Apr 1;164(4):698-702.
7) Kim JW, Suzuki K, Kavalali ET, Monteggia LM. Ketamine: