Effective Use of Topical Ketamine in Managing Acute Post‐Operative Pain Following Fournier's Gangrene Surgery: A Case Report

ABSTRACT

Topical ketamine effectively reduces acute postoperative pain following Fournier's gangrene surgery, allowing for opioid reduction and enhancing patient comfort during wound care. Its use provides an alternative to systemic opioids, minimizing side effects and dependency risks. Further research is needed to optimize dosing and confirm outcomes.

1. Introduction

Ketamine is a N‐methyl‐D‐aspartate (NMDA) receptor antagonist which demonstrates analgesic effects at subanesthetic doses [1]. It can be used in cases where conventional opioid‐based analgesics are insufficient or produce undesirable side effects to treat acute or chronic pain. One specific concern is systemic opioids reliance. We present a case of a 67‐year‐old male with Fournier's gangrene with significant post‐operative pain during dressing change. The addition of topical ketamine improved pain management and facilitated a reduction in opioid requirements.

2. Case History and Examination

A 67‐year‐old male patient was admitted for intense scrotal pain related to an abscess at the base of the scrotum to the perianal region lasting 4 days. The patient had accompanying fever, chills, and generalized weakness with worsening pain, making it difficult to sit. His past medical history included type 2 diabetes mellitusT2DM, chronic kidney disease, hypertension, and obstructive sleep apnea.

3. Diagnosis and Management

Lab work was done in the emergency department on admission and revealed beta hydroxybutyrate levels of 1.40 mmol/L, anion gap of 17, and blood glucose > 400 mg/dL consistent with mild DKA.

CT Abdomen and pelvis with IV contrast was done and showed soft tissue gas bubbles extending from the left perianal region into the scrotum, scrotal wall thickening, and edema. Imaging results suggested perianal fistula and Fournier's gangrene.

4. Management

The patient was transferred for scrotal and perineal debridement for necrotizing soft tissue infection. Surgical debridement of all the necrotic tissue from the base of the scrotum reaching to the bleeding edge of healthy tissue was done down to the perineum until close contact with the sphincter muscle complex, which was not involved. Tissue samples and swabs were sent for culture. The patient was also started on intravenous antibiotics, 3.375 gmg piperacillin/tazobactam every 6 h and 500 mg metronidazole every 6 h. The wound culture revealed Streptococcus anginosus and Staphylococcus lugdunensis . At discharge, antibiotics were discontinued, and local wound care was advised. The patient reported significant pain during dressing changes requiring high doses of systemic opioids, including 50 mcg Fentanyl IV during dressing changes and 10 mg oxycodone every 8 h. A ketamine‐based regimen was initiated, with 20 mg ketamine diluted in 8 mL sterile water for wet‐to‐dry dressing changes twice daily. This approach helped significantly reduce pain from a Visual Analog Scale (VAS) score of 8/10 at rest to 2/10 at rest during dressing changes. The use of topical ketamine also reduced the need for opioid dosages from 10 mg oxycodone to 5 mg oxycodone, and fentanyl was discontinued completely.

5. Outcomes and Follow Up

Treatment with saline soaked wet‐to‐dry dressings was continued twice daily to the perineal wound post‐operatively. During the first postoperative follow‐up 10 days after discharge, the patient reported significant discomfort with wound changes and was prescribed 10 mg oxycodone prior to dressing changes.

During the outpatient follow up 2 weeks later, the patient reported changing the dressing twice daily as previously instructed with improvement in discomfort to the scrotal region. He denied foul smelling drainage from the wound or peristomal skin irritation since the last office visit.

6. Discussion

Retrospective analyses have reported that topical ketamine reduces postoperative pain in 40%–70% of cases, underscoring its efficacy in wound management [1]. The NMDA receptor antagonist properties of ketamine contribute to its analgesic effects. Ketamine inhibits NMDA receptors (NMDARs), which are found both in the spinal cord and peripherally in sensory afferent nerve endings [1]. This inhibition prevents calcium ion influx through NMDAR channels, thereby reducing pain [2]. Additionally, ketamine has been shown to regulate inflammatory responses, decreasing levels of pro‐inflammatory mediators and suppressing early postoperative inflammation [1].

In this case, by using topical ketamine in a wet‐to‐dry dressing, the patient's opioid requirement decreased from 10 mg oxycodone every 8 h to 5 mg oxycodone, and fentanyl administration was discontinued entirely. The reliance on opioids for postoperative pain control is a significant concern due to potential dependency and adverse effects [3]. Topical ketamine, as seen in this case, suggests effective pain control without notable systemic side effects. This finding aligns with prior case reports on the use of topical ketamine for severe pain management [4, 5]. In a patient with stage IV decubitus ulcers, the use of ketamine gel drastically reduced both opioid use and pain levels over several months with minimal side effects [4]. Topical ketamine was also used for treatment of painful lip lesions due to stage 4 lymphoma and paraneoplastic pemphigus with successful reduction in VAS pain score from 5/10 to 0/10 with discontinuation of opioids [5].

In addition to its analgesic effect, ketamine may have exerted local anti‐inflammatory action, potentially dampening pro‐inflammatory cytokine activity seen in biological inflammatory syndromes associated with necrotizing infections.

Intravenous ketamine infusions are being used for acute pain as well as chronic non‐cancer pain such as complex regional pain syndrome (CRPS), neuropathic pain, and other refractory chronic pain conditions but are limited due to their associations with psychotomimetic effects such as euphoria, dysphoria, psychomotor retardation, hallucinations, vivid dreams, and nightmares as common side effects [6]. Similarly, topical ketamine has been shown to alleviate neuropathic pain, with minimal adverse effects [7]. Studies have also shown that local cutaneous ketamine is as effective as lidocaine‐prilocaine (EMLA) cream [8].

An additional consideration is the impact of ketamine on wound healing. Previous studies suggest that topical ketamine does not negatively affect postoperative healing duration or rate, or induce adverse effects [2, 9].

Additionally, the patient in our case also had chronic kidney disease. As CKD patients are more vulnerable to opioid accumulation and toxicity due to impaired renal clearance, topical ketamine makes it safer for patients with CKD to avoid these adverse effects. Although a rare case of systemic ketamine toxicity following topical application has been reported [10], the patient exhibited no signs of toxicity. However, further studies and clinical trials are needed to establish standardized dosing regimens.

7. Conclusion

This case highlights the efficacy of topical ketamine in managing acute postoperative pain following extensive debridement for Fournier's gangrene. Topical ketamine helps reduce opioid use and improve comfort during dressing changes, making it a useful option for pain management. Given the results observed in this case and other reports, further research is needed to explore the use of topical ketamine in postoperative wound care.

Author Contributions

Aariya Srinivasan: conceptualization, visualization, writing – original draft, writing – review and editing. Sabry Ayad: conceptualization, supervision, validation, visualization, writing – review and editing. Madeline Dow: conceptualization, visualization, writing – original draft, writing – review and editing. Renata Barbosa Dos Santos: conceptualization, supervision, visualization, writing – review and editing.

Consent

Written informed consent was acquired from the patient whose case details are written in the study to publish this report in accordance with the journal's patient consent policy.

Conflicts of Interest

The authors declare no conflicts of interest.

Srinivasan A., Dow M., Santos R. B. D., and Ayad S., “Effective Use of Topical Ketamine in Managing Acute Post‐Operative Pain Following Fournier's Gangrene Surgery: A Case Report,” Clinical Case Reports 13, no. 7 (2025): e70625, 10.1002/ccr3.70625.

Data Availability Statement

The data supporting this report's findings are available on request from the corresponding author. The data is not publicly available due to privacy or ethical restrictions.