Hyperbaric Oxygen Therapy in Frostbite

A Case Series

Abstract

A team of 10 personnel from a mountaineering team has undertaken an expedition to Mt Menthosa at an altitude of 21138 ft. in October 2018. After scaling the peak and in the following days during descent, the three members of the team had developed cold injuries. They were given first aid during descent. Later, they were diagnosed as cases of frostbite. All three personnel were evacuated to a Military Hospital, Delhi, India and were treated with oral vasodilators, antiplatelet drugs, analgesics, and hyperbaric oxygen therapy (HBO₂T) was administered at a Recompression chamber at Delhi for 1 week. These personnel were thereafter referred to INHS Asvini for further management and continuation of HBO₂T. After 30 sessions of HBO₂T administration at this hospital, there was a significant improvement in the wounds of all three personnel with minimal surgical intervention and no major amputation. The treatment of frostbite includes treating hypothermia before thawing of cold injury, nonsteroidal anti-inflammatory drugs, antibiotics, tissue plasminogen activators and iloprost, a potent vasodilator which is used in severe cases. Planning of surgery is vital with the goal of obtaining the best functional outcome. Premature amputation increases morbidity and is likely to lead to poor subsequent function. This article aims to discuss the advantages of HBO₂T administration as an adjuvant therapy in the management of frostbite cases along with wound care management.

INTRODUCTION

Frostbite is a form of cold injury which results due to acute freezing of the skin and deep tissues and can lead to potential serious tissue damage and necrosis. Frostbite usually develops following exposure to temperatures below − 2°C for more than 1 h without adequate protective clothing.[¹²] The severity of frostbite is related to vascular insufficiency, altitude, duration of exposure, tissue wetness, previous exposure to cold injury, age, and other factors.[³] Thromboxanes and prostaglandins also play an important role in frostbite injuries.[⁴] Frostbite is classified into four degrees, with superficial frostbite comprising the 1^st and 2^nd degrees and deep frostbite 3^rd and 4^th degrees.[⁵]

Despite the increase in the number of persons at risk (due to outdoor activities and homelessness[⁶]), data on the incidence and morbidity are scarce, large randomized clinical trials are not feasible and standard treatment guidelines based on a high level of evidence are lacking. Good results have been reported in the treatment of problem wounds and frostbite by administering hyperbaric oxygen, but limited reports on the treatment of frostbites using hyperbaric oxygen have been published.[⁷] A case series of three patients is presented where adjuvant hyperbaric oxygen therapy (HBO₂T) was used for the treatment of these frostbite patients.

A team of ten personnel from a Mountaineering Team had undertaken an expedition to Mt Menthosa in Lahol-Spiti range, Himachal Pradesh, at an altitude of 21,138 ft. The planned duration of expedition was from October 5, 2018, to October 20, 2018, including 1 week of acclimatization. Team started climbing on October 12, 2018 and reached the peak on October 16, 2018. After scaling the peak and in the following days during descent, three members of the team suffered cold injuries. These were given first aid at the MI rooms on the way down and evacuated to a service hospital at Delhi where they were diagnosed with patients of frostbite. They were treated with oral vasodilators, antiplatelet drugs, and analgesics, and HBO₂T was administered at a recompression chamber at Delhi for 1 week. These personnel were thereafter referred to INHS Asvini for the further management and continuation of HBO₂T. All three patients were treated in a multi place chamber at Department of Marine and Hyperbaric Medicine, INHS Asvini from November 01, 2018. A diving attendant was present with patients during HBO₂T. All the patients were given HBO₂T at 2.4 ATA for 90 min using 100% oxygen using a mask with intermittent air breaks, 6 days a week, on an inpatient basis. Wound care was given daily.

CASE SERIES

Patient 1

This was a 26-year-old male patient with complaints of discoloration, heaviness, swelling, and numbness of the 1^st, 2^nd, 3^rd, and 5^th toes in the left feet with symptom onset from October 16, 2018. These symptoms gradually progressed with bluish to blackish discoloration of digits. He had no comorbid illness and with no significant past medical/surgical illness. He was a non-smoker. General and systemic clinical examinations were unremarkable. Local examination findings included circumferential swelling of left great toe, second, third and fifth toes, dry skin with blackish discoloration, without clear line of demarcation. The swellings were hard on palpation; pain and touch sensations were decreased. There was serous discharge from the 2^nd web space. Color Doppler flow imaging (CDFI) of the affected limb revealed the normal study.

During early HBO₂T treatments, there was visible pink color at the borders of the affected parts, and the patient reported an increase in pain as sensation returned to the affected toes. Over the course of the series of HBO₂T, all toes, except for the first toe, showed marked improvement with revitalization of ischemic tissues. The first toe of the left feet became hard and cold with dry eschar [Figure 1] 21,138 ft. After 30 sessions of HBO₂T recovery was complete in all toes, except the left great toe for which the Amputation of distal phalanx was done by plastic surgeon of the hospital [Figure 2].

Figure 1: Left foot before hyperbaric oxygen therapy

Figure 2: Left foot after 30 sessions of hyperbaric oxygen therapy and left great toe distal phalanx amputation

Patient 2

This was a 23-year-old male arrived at this department with complaints of discoloration, heaviness, swelling, and numbness of left index and middle fingers of the left hand with symptom onset from October 17, 2018. These symptoms gradually progressed with bluish to blackish discoloration. He has no comorbid illness and no significant past medical/surgical history. He was a nonsmoker. General and systemic examination was unremarkable. Local examination findings included circumferential swelling of left index and middle fingers, dry skin with blackish discoloration, with no clear line of demarcation, swellings were firm on palpation. Pain and touch sensations were decreased, and there was no discharge. CDFI of the affected limb was normal.

During early hyperbaric treatments, there was pink discoloration at the border of the affected and unaffected part [Figure 3], and the patient did not report any increase in pain after HBO₂T sessions. After 30 sessions of HBO₂T recovery was complete in both the fingers, without any residual or physical damage or surgical intervention [Figure 4].

Figure 3: Left index and ring finger before hyperbaric oxygen therapy

Figure 4: Left index and ring finger after 30 sessions of hyperbaric oxygen therapy

Patient 3

This was a 28-year-old male who presented with complaints of pain, discoloration, swelling, and blisters of left middle finger and right ring finger with symptom onset from October 16, 2018. These symptoms gradually progressed with bluish to blackish discoloration. He had no comorbid illness and no significant past medical/surgical history. He was a nonsmoker. General and systemic examination was unremarkable. Local examination findings included circumferential swelling of left middle finger and right ring finger, blackish discoloration, without clear line of demarcation, swellings were firm on palpation. The pain and touch sensations were reduced on affected fingers, and serious discharge from the blisters was present. CDFI of the affected limb was normal.

During initial hyperbaric treatment, there was pink discoloration at the border of the affected and unaffected parts [Figure 5], with no clear line of demarcation. After 30 sessions of HBO₂T recovery was complete in both fingers, without any residual physical or functional morbidity and surgical intervention [Figure 6].

Figure 5: Left middle and right ring fingers with blisters before hyperbaric oxygen therapy

Figure 6: Left middle and right ring fingers after 30 sessions of hyperbaric oxygen therapy

DISCUSSION

Frostbite was once mainly a military problem.[⁴] However, with recent increased participation by the civil population in outdoor winter activities (skiing, mountain climbing, etc.) and increased homelessness, the incidence of frostbite in the civilian population has also increased.[⁶] Our patients were engaged in outdoor pursuits when they suffered frostbite. Only after repeated questioning, they revealed that they had taken off their gloves and boots for some time while at high altitude. In frostbite ratio of reversibly injured cells is higher than that of irreversibly injured cells, and these reversibly injured cells may recover and survive with appropriate treatments.[⁸] The anatomical sites most susceptible to frostbite are the hands and feet, which constitute 90% of frostbite injuries. Adults population aged between 30 and 49 years is the most commonly affected.[⁹] Immediate treatment consists of rewarming the affected sites with warm water (40°C–42°C), although not warmer than 44°C.[⁴] Tetanus prophylaxis and analgesia have to be provided and the affected areas should be protected from frictional injuries. The extremity concerned must be elevated and splinted immediately to reduce edema and promote tissue perfusion as well as drainage.

Tissue damage in freezing occurs by two means: Cellular damage and vascular insufficiency. Slow freezing leads to the emergence of more ice crystals in the extracellular tissue. This causes dehydration of cells, which leads to protein denaturation, inhibition of DNA synthesis, loss of cellular membrane integrity, and finally cellular death. Cold causes increased blood viscosity and vasoconstriction leading to thromboembolism.[¹⁰] The pathophysiological mechanisms of frostbite have marked similarities to those seen in thermal burns, ischemia/reperfusion injuries, and crush injuries, –i. e., nonhealing wounds and inflammatory processes.

Patients should have protection from further injury by covering exposed areas. The care of patients with frostbite begins with rewarming in the field if there is no anticipation of refreezing, as thaw-refreezing may worsen injuries.[¹¹] Nonsteroidal anti-inflammatory drugs (ibuprofen) and antibiotics are indicated for controlling pain and preventing further inflammation and secondary infection, but stronger analgesics including narcotics may be necessary to achieve pain control. Frequent re-examination for sensation should accompany rewarming. Patients with full-thickness injuries and evidence of ischemia and no restoration of tissue perfusion after rewarming may be candidates for thrombolytic therapy with tissue plasminogen activator.[¹²] Iloprost, a potent vasodilator, has been used as a potential treatment to prevent ischemia in frostbite.[¹¹] Immediate amputation should be avoided; there is rarely any need for early intervention unless there is wet gangrene, liquefaction, overwhelming infection, or spreading sepsis.[¹³] Planning is vital with the goal of obtaining the best functional outcome. Premature amputation increases morbidity and is likely to lead to poor subsequent function.

The first case of HBO₂T treatment in frostbite injury was reported by Ledingham.[¹⁴] Good results have been reported in the treatment of problem wounds and frostbite by administering adjuvant HBO₂T.[⁷] HBO₂T increases leukocyte bactericidal activity, resistance to infection, promotes growth of new capillaries, increased collagen synthesis and storage, and oxygen-sensitive fibroblast replication in affected tissue[¹⁵¹⁶] by increasing the normal level of tissue oxygen pressure by 10–15 times.[¹⁷] At the same time, HBO₂T regulates microcirculation and reduces edema by causing vasoconstriction without causing hypoxia.[¹²] The increased local tissue oxygen tension by hyperbaric oxygen treatment improves and maintains the viability of the adjacent tissue. Therefore, vascular and cellular regeneration occurs in a faster and more efficient way.

CONCLUSION

The aim of frostbite treatment must be to salvage more irreversibly injured cells. In the early stages of freezing, HBO₂T can assist in the salvaging of a greater amount of tissue by increasing the viability of reversibly damaged cells adjacent to necrotic tissue by preventing tissue hypoxia and reducing tissue edema. In the late stage, it shortens the duration of hospitalization and reduces the development of secondary infection by accelerating wound healing. At the same time, HBO₂T assists the surgeon by the development of a clear demarcation line and increases the success of surgical interventions planned for tissue defects. This case series adds further evidence that timely adjuvant HBO₂T can aid in salvaging maximum tissue affected by frostbite. All our three patients had excellent recovery as a result of first aid during descent, early initiation of medical treatment, and adjuvant HBO₂T with daily wound care. This was augmented with timely surgery in one patient. As with prior case reports, the weight of the evidence is limited by a lack of a treatment control which is not realistic to obtain as it would be unethical not to provide HBO₂T once a patient reaches a hospital where such a therapy is available. Further research using comparison with patients treated at the hospital where this therapy is not available can further strengthen the evidence in favor of the use of HBO₂T for all patients with frostbite.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.