Wound Clinic Case Report: Role of HBOT in Delayed Presentation of Frostbite After Freon Exposure

Freon gas is a halogenated hydrofluorocarbon derivative widely used in refrigeration and air conditioning, and its contact with skin may cause serious burns. This article presents a case of a 58-year-old male who presented to the wound clinic. 

Introduction

Freon gas is a halogenated hydrofluorocarbon derivative widely used in refrigeration and air conditioning. Maintained at a temperature of -40°C, its contact with skin may cause serious burns. Frostbite from chemical exposure is relatively uncommon in presentation, and cryogenic frostbite from exposure is usually Grade III or IV. Hyperbaric oxygen therapy (HBOT) has been used as principal and adjuvant therapy for a range of medical conditions and in wound care. HBOT is used to augment oxygen content and to independently meet resting tissue oxygen requirement. This augmentation of oxygen delivery is used to manage acute and chronic ischemia. 

This article will present a case of a 58-year-old white male who presented to an outpatient wound clinic after exposure to freon on his right hand. After 20 HBOT treatments, along with skin substitute grafting, there was significant improvement in the injury as well as symptoms — such that the need for amputation was avoided. The authors believe HBOT could be used as primary or adjuvant treatment in management of cryogenic frostbite from freon exposure, even with delayed presentation.

Illustrative Case

The patient, a car mechanic, presented to the wound clinic approximately nine days after accidental freon exposure. At the time of the incident, the patient was repairing an automobile air conditioner when he realized freon was dripping onto his right hand. Contact with the agent lasted approximately one minute (Figure 1). He rinsed his hand and was seen by a physician in an outpatient urgent care setting approximately two days post-exposure. During that visit there was reported discoloration of digits 2-5 and amputation was recommended. However, he feared he would be unable to work, refused amputation, and failed to follow up until visiting his primary care physician about one week from time of the exposure. He was at that time promptly referred to the wound clinic for a second opinion. He complained of severe pain and presented with discoloration and swelling in the affected digits.

Physical examination included normal vital signs, but the patient was in mild distress secondary to pain. Examination of the right hand revealed purple discoloration along with a mottled appearance from the proximal interphalangeal joints to the tips of the 2nd-5th digits, as well as vesicles on the distal phalanx of the 4th and 5th digits. The digits were cool to touch, and capillary refill was prolonged but could not be quantified due to intense discoloration. The digits also were extremely tender. The rest of the physical exam was benign. Possible treatment modalities were discussed with the patient. Since the presentation was delayed, the usual treatment modalities, including rapid rewarming and heparinization, could not be initiated. The patient wanted to save his digits and opted for HBOT. HBOT protocol was used at 2.0 atmospheres absolute for 90 minutes with no air breaks. The patient initially had twice-daily treatments (for a total of five treatments), then daily dives for 15 treatments. Because severe ear pain occurred after the first treatment and ear examination confirmed hyperemia of the tympanic membrane, the patient underwent tympanostomy tube placement. He then tolerated HBOT well. Even as quickly as following the first treatment, the digits started turning red with improvement in the swelling as shown in Figure 2 and Figure 3 (both on page 11). The vesicles were debrided after five treatments (48 hours after initial presentation to the wound clinic). Because the patient requested the most rapid possible resolution, amnion chorion cellular tissue product was selected. HBOT was then resumed and symptoms significantly improved with complete resolution by Day 20 (Figure 4 page 11). The patient was then discharged from the clinic.

Discussion

Frostbite is a severe, localized, cold-induced injury due to freezing of tissue. The tissue destruction of frostbite is due to both immediate cold-induced cell death and the more gradual development of localized inflammatory processes and tissue ischemia.^1,2 Once exclusively a military problem, frostbite is now frequently encountered in mountaineers and other cold-weather enthusiasts, those who work in the cold, the homeless, and those individuals stranded outdoors during winter.^1,3,4 There are also reports of frostbite from exposure to chemical agents, both liquids and gases. The literature is sparse in relation to cryogenic frostbite and mostly restricted to a few case reports.^5-7 The only retrospective study (with a sample size of 17 patients) is out of Istanbul, Turkey. That study evaluated the different etiologies of frostbite and treatment modalities.⁸ Freon was initially thought to be safe, but has been subsequently found to be toxic to the environment, with most cases of accidental contact being reported as work-related injuries.^5-8 As with injuries due to other compressed gases, the upper extremities are more susceptible than the lower extremities, with a younger age preponderance.⁹ 

The extent of injury as a result of exposure depends on time of exposure, surface area of exposure, and quantity of exposure. Frostbite from chemical exposure may cause cellular destruction and arterial vasoconstriction leading to disordered vascular flow patterns and damage to the microcirculation. Freon has been reported to cause third- and fourth-degree frostbite.^5,10 

Unfortunately, early clinical presentation is often reassuring and does not reflect the actual depth of injury. Currently, there are no recommendations for management of these exposures, with limited cases reported. Initial management should be directed toward prevention of secondary exposure and toward rapid rewarming to 40°C. Heparinization for the prevention of thrombosis is controversial. In the first few days after thawing, thrombosis has been seen and heparin has been used to prevent intravascular thrombosis. Unlike with thermal burns, the effects of an offending agent will continue until the contact is removed, as the agent is absorbed through the skin. Early presentation to the emergency department and early treatment are imperative, even though the initial presentation is reassuring.⁸ 

Clinical evidence is sparse when it comes to the role of HBOT in the delayed presentation after frostbite and is limited to a few case reports. The authors found three case reports written in English literature of frostbite in digits from freezing environmental exposure with delayed presentation where HBOT was used in management. All the cases reported on patient presentations ranging from 14-21 days after exposure. HBOT did prevent amputations in all cases.^11-13 These reports are used here as a benchmark and could extrapolate to management of this case presentation, as the pathology and time of presentation was similar. There are even fewer cases of cryogenic frostbite that are effectively treated with HBOT.¹⁴ In each of the two reported cases the initial presentation was between 2-96 hours after exposure. The authors did not uncover case reports in the English literature in which cryogenic frostbite was treated after a delay of more than 96 hours with a successful outcome.

Conclusion

This case report shows a positive outcome with the use of HBOT on cryogenic frostbite with delayed presentation. In cases of chemical exposure, treatment should be initiated immediately, as skin absorption of chemical agents means the progression of the disease processes continues even after cessation of exposure. Freon has been reported to cause irreversible damage, but even in these extreme circumstances this case report shows HBOT can have a positive outcome in cryogenic frostbite with delayed presentation. The number of treatments may vary, as there are no standardized recommendations. The authors used a total of 20 treatments and believe HBOT could be used as the first line in the management of frostbite from freezing or cryogenic etiology. Earlier notions of the ineffectiveness of HBOT after a delay of 24 hours should not be considered standard, and HBOT should be started immediately without delay. The authors also believe that in cases of delayed presentation of frostbite from both cryogenic and freezing etiology consideration should be given to a trial of HBOT before amputation is planned. 

Anil S. Matta is medical director, hospitalist services at Natchitoches (LA) Regional Medical Center. Kelly Browning is clinical nurse manager at the Natchitoches Regional Medical Center wound clinic. Robin McCalister is currently working in a family practice in Conway, AR. At the time of the study she was hyperbaric safety director at the Natchitoches Regional Medical Center wound clinic. Frank Aviles Jr is wound care service line director at Natchitoches Regional Medical Center; wound care and lymphedema instructor at the Academy of Lymphatic Studies, Sebastian, FL; physical therapist/wound care consultant at Louisiana Extended Care Hospital, Lafayette; and physical therapist/wound care consultant at Cane River Therapy Services LLC, Natchitoches.  

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