A minimally invasive technique using fenestrated angiocatheters has been described in adult literature for the treatment of extensive subcutaneous emphysema. Here we report a 30 month old infant who developed extensive subcutaneous emphysema and pneumomediastinum, which was relieved by application of microdrainage catheters.

Key words: Acute respiratory distress syndrome, Pneumomediastinum, Subcutaneous emphysema.

Subcutaneous emphysema is a known complication of invasive procedures, some surgical interventions, and medical conditions with airway obstruction. It may also occur during mechanical ventilation for acute respiratory distress syndrome (ARDS) and can be traced to pneumomedia-stinum with or without a pneumothorax. Any condition that creates a gradient between intra-alveolar and perivascular interstitial pressures can create pneumo-mediastinum with subcutaneous emphysema. The condition causes disfigurement, discomfort and anxiety, but rarely airway compromise and respiratory failure. The management is generally conservative but for severe cases, micro-drainage is described in adult patients.

Case Report

A 30-month old boy with acute lymphoblastic leukemia, who developed febrile neutropenia and severe respiratory failure requiring intubation after the first induction chemotherapy. Despite broad coverage antibiotic, antifungal and antiviral therapy, the child developed ARDS. Open lung and permissive hypercapnia strategy was followed. Despite the lung protective strategy he developed a left sided pneumothorax which was easily relieved by a pigtail catheter, followed by the development of pneumomediastinum and massive subcutaneous emphysema from the head towards the scrotum. Escalated ventilatory requirements without any other identifiable cause suggested that his massive subcutaneous emphysema combined with pneumomediastinum was creating restrictive pattern for ventilation. Literature search revealed a simple potential solution with modified-fenestrated angiocatheters. We chose to use 18 gauge catheters due to the size and skin condition of the child. Two angiocatheters were prepared at the bedside under sterile conditions as described by Beck, et al. [1], with minor modifications. Due to the smaller size of the chosen catheter, only five holes were opened using a scalpel, three at the top and two at the bottom of the plastic while the needle was in situ. The area of insertion was also modified. Instead of using the infraclavicular region we chose to stay away from the vascular port site and decided to use the area of most swelling which corresponded to low thoracic region at the midaxillary line. After preparation of the area with chlorhexidine scrub and draping, the modified catheters were inserted subcutaneously with 40-45 degree angle, about 0.5-1 cm aiming cephalad, and redirected in parallel plane to full insertion. The angiocatheters were taped to skin with a clear adhesive tape and connected to underwater seal drains aiming for a closed system and for allowing direct visualization of air evacuation. Compressive massage was applied by nurses towards the draining angiocatheters every four hours. Drainage of air was enhanced with massaging, which was verified by the simultaneous observation of bubbling in the water seal chamber. The angiocatheters were kept in place for 24-48 hours until the cessation of bubbling. Within 24 hours, substantial improvement of ESE was observed. The pneumomediastinum also decreased, albeit more slowly, with complete resolution occurring in five days. The ventilator support could be weaned, and the patient was successfully extubated in five days. There were no associated complications with insertion of the subcutaneous angiocatheters. The patient was transferred back to the wards one week after the extubation. He remains well at home on his maintenance chemotherapy regimen six months after his intensive care stay.

Discussion

Various invasive and uncomfortable techniques have been used to treat extensive subcutaneous emphysema, with potential of inducing subcutaneous emphysema themselves. Infraclavicular incisions, placement of additional chest tubes through either intrapleural or subcutaneous route, and insertion of large bore subcutaneous drains with or without suction, and tracheostomy were traditional options for treatment. The successful micro-drainage of the subcutaneous emphysema with simply constructed angiocatheters was first described by Beck, et al. [1]. This was followed by three other adult case reports [2-4]. Leo, et al. [5], also reported their experience with microdrainage catheters in their retrospective review of 12 patients from the European Institute of Oncology database after major thoracic surgeries. The procedure was reported to be effective and free of complications [5].

Our patient required increasing ventilatory pressures despite tolerance of permissive hypercapnia after development of ESE and pneumomediastinum, and only after microdrainage we were able to wean the supplemental oxygen and ventilatory pressures. This observation suggests that subcutaneous air can potentially create a restrictive defect during ventilation of already diseased lungs. We observed that this minimally invasive technique was simple, and effective in our patient, and does not have a potential for serious complications. We propose that this procedure may be considered as a first line therapy for symptomatic ESE in sick children.

Contributors: All authors contributed in the patient management and manuscript preparation.

Funding: None; Competing interests: None stated.

References

1. Beck PL, Heitman SJ, Mody CH. Simple construction of a subcutaneous catheter for treatment of severe subcutaneous emphysema. Chest. 2002;121:647-9.

2. Ozdogan M, Gurer A, Gokakin AK, Gogkus S, Gomceli I, Aydin R. Treatment of severe subcutaneous emphysema by fenestrated angiocatheter. Intensive Care Med. 2005;31:168.

3. Perkins LA, Jones SF. Resolution of subcutaneous emphysema with placement of subcutaneous fenestrated angiocatheter. Respiratory Medicine Extra. 2007;3:102-4.

4. Srinivas R, Singh N, Agarwal R, Aggarwal AN. Management of extensive subcutaneous emphysema and pneumomediastinum by micro-drainage: time for a re-think? Singapore Med J. 2007;48: e323-6.

5. Leo F, Solli P, Veronesi G, Spaggiari L, Pastorino U. Efficacy of microdrainage in severe subcutaneous emphysema. Chest. 2002;122:1498-9.