Benign subcutaneous emphysema treated with hyperbaric oxygen therapy after surgical exploration

Abstract

Benign subcutaneous emphysema of the upper limb is extremely uncommon. Patients with this condition that involves the limbs usually present with local symptoms, and they are systematically well. We report a case of 18-year-old male presented after a minor cut wound in the forearm with diffuse subcutaneous emphysema. The patient was treated with hyperbaric oxygen therapy after wound exploration. Recovery was uneventful. Infectious etiology by gas-forming organisms should be ruled out before considering other causes.

Introduction

Subcutaneous emphysema is defined as a collection of air in the subcutaneous tissue mainly involving the extremities. It is a rare presentation which is only documented by small collection of case reports.^{1, 2, 3, 4, 5} The underlying causes range from serious infections such as gas gangrene and necrotizing fasciitis to more benign causes such as simple trauma.^2,5 History, physical examination, lab tests, radiological tests, and sometimes surgical exploration would aid in ruling out infectious etiology. In trauma-related cases, conservative management and patient reassurance would be enough.^2,3,5 Adding hyperbaric oxygen therapy could theoretically accelerate gas clearance^3,8 as what we did for our patient. Patient consent was obtained for images and inclusion in the study.

Case report

An 18-year-old male patient who was a worker in a biscuit factory and had no previous medical illnesses was injured in his left forearm by a sharp object. His cut wound was about 2 cm in length in the posterior aspect of the left forearm. The patient went to a private general practitioner (GP), and his wound was sutured. Two days later, the patient developed swelling and pain in his whole left upper limb (Fig. 1). There was no shortness of breath, no chest pain, and no fever. On physical examination, his vitals were normal, O₂ sat was 100%, and swelling and crepitus were noted. Complete blood count and routine blood chemistry were within normal limits. Radiograph and computed tomography (CT) scan showed emphysema involving whole left upper limb but no pneumothorax (Fig. 2a). Owing to the possibility of infectious etiology with the gas forming organism in such cases, we performed wound exploration and identified the wound site on the left forearm. Air escaped when we made our incision, but the subcutaneous tissue, fascia, and muscle were found to be normal, and there was no pus. Tissue and swab culture were taken, and the results were negative. Based on our experience in treating decompression sickness patients with hyperbaric oxygen therapy and its role in decreasing bubble size and washing them out, we gave the patient one session in the hyperbaric oxygen therapy chamber at 2.4 bar for 100 min US Navy treatment table 9.¹⁴ On the same day, follow-up radiograph and CT scan showed complete resolution of the emphysema (Fig. 2b). The patient was evaluated 2 weeks later on follow-up, and he was completely asymptomatic with healed wound and no emphysema.

Fig. 1.

Swelling involving left forearm of the patient showing the sutured cut wound.

Fig. 2.

(a) Radiograph and CT scout film of the patient at presentation showing extensive subcutaneous emphysema. (b) Radiograph of the same patient after treatment with hyperbaric oxygenation showing complete resolution of the emphysema. CT, computed tomography.

Discussion

Subcutaneous emphysema of the upper limb is an extremely rare condition with a small number of cases reported in the literature.^{1, 2, 3, 4, 5} The etiology of this condition is usually classified as infectious or non-infectious. Necrotizing fasciitis and gas gangrene (clostridial myonecrosis) account for the infectious cases.^{4,6, 7, 8}

Non-infectious cases (in which emphysema is usually designated as benign) are mostly trauma related. Emphysema may follow simple wounds, pneumatic tools injury, migration of internal fixation devices, insect bites, and surgical procedures on hand.^1,2,5,6 The proposed mechanism of emphysema after such injuries is thought to be related to the ball-valve mechanism in which the air is drawn into the subcutaneous tissue and is trapped there.^1,7,9 History, physical examination, lab tests, and radiological tests are needed to confirm the presence of emphysema and exclude the presence of serious infections. In some cases, surgical exploration is carried out to rule out necrotizing infections.^1,6

In cases of benign surgical emphysema, the patient can safely be reassured as the condition is self-limiting and can be treated conservatively.^{1,5,6,9, 10, 11, 12, 13} As hyperbaric oxygen therapy is known to decrease bubble size by high pressure and enhance nitrogen washout by high oxygen concentration, this form of therapy was tried. The patient was given one session in accordance with US Navy treatment table 9 in a multiplace chamber: 100 min at a pressure of 2.4 barwhile breathing 100% oxygen.¹⁴ CT scan and radiograph done shortly after treatment showed complete resolution of the emphysema. Balas et al.³ reported the same finding and reached a conclusion that hyperbaric oxygen therapy could be the treatment of choice in such cases. Recently De Roeck et al.⁸ reported a similar case to ours where hyperbaric oxygen therapy resulted in fast and complete recovery.

Conclusion

Surgical emphysema of the upper limb is rare. Care should be taken to rule out an infectious etiology. In benign (non-infectious) cases, patients can be managed conservatively. Hyperbaric oxygen therapy (if available) is recommended to accelerate recovery, although more research in this field is still needed.

Conflicts of interest

The authors have none to declare.