Irrigation with Liquid Sevoflurane and Healing of a Postoperative, Recurrent Epidural Infection: A Potential Cost-Saving Alternative

Seeing is Believing: Chasing Sevoflurane Vapor Trails

PURPOSE

Sevoflurane is an inhalational general anesthetic that has been used recently to treat chronic, painful lesions, reportedly supporting analgesia and wound healing. The potential for repeated exposure to off-gassed sevoflurane vapor, especially outside the air-conditioned operating theatre environment, is of some concern.

DESIGN

This paper explores the qualitative and quantitative pathing of off-gassed sevoflurane from a topically applied liquid source.

METHODS

Using a small, unventilated test-box (total volume 0.5 m3) with infra-red imaging and gas-analysing, we investigated the spatial distribution of sevoflurane vapor following complete vaporization of a 20 mL liquid sample. Utilizing the infra-red absorption of sevoflurane, it was possible to visualize (as an apparent reduction in temperature) the streaming path of the sevoflurane vapor. Sevoflurane levels (%) in the test-box were measured using an infra-red gas analyzer.

FINDINGS

In keeping with its higher density than air, sevoflurane vapor was seen to "waterfall" from the liquid source and accumulate in the bottom of the test-box. Sevoflurane vapor concentration was minimal above the liquid source. When extrapolated to a larger (unventilated) room, we estimate that the sevoflurane concentration would be less than 10 ppm one centimetre above the liquid pool. With vacuum extraction, these levels would be even lower.

CONCLUSIONS

Due to sevoflurane's tendency to accumulate on the floor, it is concluded that topical application of liquid sevoflurane posses virtually no risk to off-gas exposure in unventilated spaces.

Clinical and histological safety assessment of repeated intra-articular sevoflurane injections into knee joints of Sprague-Dawley rats

Objectives

We investigated the effects of repeated intra-articular injections of liquid sevoflurane to articular structures, as this inhalational anesthetic is being repurposed as an antimicrobial agent, which would make sevoflurane a novel alternative for the treatment of septic arthritis.

Methods

The left knees of nine Sprague-Dawley rats were injected with 150 μL of liquid sevoflurane for five consecutive days, whereas the right knees were injected with the same volume of saline to serve as controls. Animals were examined daily for clinical signs of local and systemic toxic effects attributable to sevoflurane. Rats were euthanized in groups of three at days 7, 14, and 35 after the first injection, and left and right knees were sent for histological assessment.

Results

Local signs on knees consisted of transient bilateral scabs, and an unexpected subcutaneous emphysema affecting only left knees, which was attributed to sevoflurane. No rat presented with limp, and animal welfare was good during the study period. Two out of the three left knees from rats sacrificed at day 7 showed mild histological changes, specifically a mild infiltration of lymphocytes. All other seven left knees as well as all nine right knees were completely normal at histological examination.

Conclusion

We concluded that repeated intra-articular injections of sevoflurane seemed safe for articular structures in noninfected knees. Further studies focused on the safety of intra-articular sevoflurane in infected knees, as well as on its effectiveness for the treatment of septic arthritis are warranted.

Use of topical sevoflurane in pressure ulcer treatment in a double-lung transplant patient

Pain caused by wounds of different etiology is usually treated with oral analgesics. New topical use of products such as the ether anesthetic sevoflurane shows good results for pain control and has additional benefits. Pressure ulcers are painful and patients may benefit from the use of sevoflurane. We present the case of a double-lung transplant patient with a long-standing sacral pressure ulcer with poor pain control, for which sevoflurane dressings were used. The number of pain-free hours after application, the amount of daily analgesics and the size of the wound were monitored with the mobile wound application MOWA. After several days of sevoflurane application, the patient reduced analgesic consumption, remained longer free of pain, and the size of the wound decreased. Unfortunately, the patient had serious complications due to multiple comorbidities and died before the wound healed completely. Topical use of sevoflurane in pressure ulcers may be a good option to treat pain and improve patient quality of life.

Analgesic effectiveness of topical sevoflurane to perform sharp debridement of painful wounds

OBJECTIVE

Analgesic topical options to perform wound debridement are scarce. The purpose of this study was to communicate our experience using topical sevoflurane as analgesic for wound debridement.

METHODS

After approval by our institutional review board, medical records were reviewed for those patients who had previously accepted to be treated with off-label topical sevoflurane (1 mL/cm²) as an analgesic for sharp debridement of painful wounds, because it was previously approved by our institutional Pharmacy Regulatory Commission and Medical Management. According to this protocol, pain scores were measured by using a numerical rating scale (from 0 to 10 points) over a 10-hour period. Wound debridement was performed following routine procedures.

RESULTS

Medical records from 152 patients were reviewed. Baseline pain was severe (median, 7 points). After topical sevoflurane application, the analgesic effect was rapid (median pain score of 2 points at 5 minutes), and full debridement was feasible in most wounds (93%). The initial intense analgesic effect lasted for 30 minutes and then it subsided gradually over time to nearly reach baseline values after 10 hours. The patients estimated that the analgesic effect lasted several hours (median, 9 hours), and their overall satisfaction was high (median of 8 points on a scale ranging from 0 to 10). Fifty-two patients (34%) experienced itching.

CONCLUSIONS

Topical application of sevoflurane to painful wounds produced a rapid, robust, and long-lasting analgesic effect, which allowed for a high degree of wound debridement.

Palliative analgesia with topical sevoflurane in cancer-related skin ulcers: a case report

A Caucasian 39-year-old male patient with a poorly-differentiated infiltrating epidermoid penile carcinoma with urethral invasion was diagnosed. The patient received concomitant adjuvant chemotherapy with radiotherapy in the palliative setting, which produced painful ulceration of tumour lesions at loco-regional level (Numerical Rate Scale, NRS=9). The patient consented for treatment with direct topical sevoflurane instillations, at initial doses of 1 mL/cm² of ulcerated area, as per unit protocol. The local use of undiluted sevoflurane achieved a marked reduction of the pain score in both nociceptive and irruptive pains (average NRS=3 immediately post-application). This improvement was corroborated by a decline in total morphine needs, any adverse events associated with major opiates. PGI-I and CGI-I scales were used before and after treatment with topical sevoflurane to assess patient and clinician perceptions of improvement in the quality of life. The pharmacy of our hospital had the responsibility to elaborate pre-loaded syringes with sevoflurane so that the patient was instilled simply and comfortably.

Pain, Quality of Life, and Functional Capacity With Topical Sevoflurane Application for Chronic Venous Ulcers: A Retrospective Clinical Study

Introduction

Chronic venous ulcers (CVU) commonly have poorly controlled pain.

Report

Thirty patients older than 65 years of age with painful CVU were reviewed. At the initial visit, cleaning without sevoflurane was performed. Cleaning visits with sevoflurane every 2 days for 1 month were scheduled. The results of subsequent treatment with sevoflurane at the first, second, seventh, and twelfth cleanings were analysed. Pain was measured using a visual analog scale (VAS), quality of life by the Charing Cross Venous Leg Ulcer Questionnaire, and functional capacity by the Barthel Index.

Discussion

Initial VAS was 8.8 ± 1.3 points and at the twelfth cleaning VAS was 0.8 ± 1 points (p = .001). Latency time ranged between 2 and 7 m and duration ranged between 8 and 18 h. It improved quality of life (83 ± 14 points before treatment vs. 50 ± 14 at the twelfth cleaning) and functional capacity (82 ± 13.3 before treatment vs. 91 ± 11.6 points at the twelfth cleaning) (p = .001). The safety profile was favourable with mild and self limited local cutaneous adverse effects, including pruritus, erythema, and heat. No systemic toxicity was detected. Topical sevoflurane may be a therapeutic alternative for painful CVU with a fast, intense, and long-lasting analgesic effect.

Topical sevoflurane for chronic venous ulcers infected by multi-drug-resistant organisms

Several anaesthetic drugs have demonstrated antibacterial properties in vitro. Anaesthetics can primarily affect the cell wall of both susceptible and multi-resistant bacteria. They may also have a synergistic effect with conventional antibiotics through an unknown mechanism. We present three cases of a chronic venous ulcer infected by multi-resistant bacteria refractory to conventional systemic antibiotics, including Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA). Treatment with topical sevoflurane was performed for 1 month without systemic antibiotics. Patients with an MRSA infection showed progressive improvement with negative culture at the end of the treatment. Multi-drug-resistant P. aeruginosa infection persisted at the end of treatment with positive culture. The local adverse events were mild and transient, including heat, pruritus and erythema. Topical sevoflurane may have an antibacterial effect on sensitive and multi-resistant strains. It can allow more complete surgical cleaning, leaving a cleaner wound with less fibrin and necrotic tissue. This decreases the bacterial colonisation and therefore the infectious risk, the bad smell and the exudation. The simultaneous use of conventional antibiotics and topical sevoflurane can have a synergistic antimicrobial effect.