Surgical Emphysema without Pneumothorax: A Diagnostic Dilemma

Introduction. Surgical emphysema, also widely known as subcutaneous emphysema, is defined as a clinical state in which air gets trapped subcutaneously. The etiology may be traumatic or atraumatic, and multiple causes in each are present. Case report. A 63-year-old female patient presented to the emergency room with a facial soft tissue injury following road traffic accident and developed surgical emphysema later on with no evidence of rib fractures or pneumothorax. Infectious etiology was ruled out. Due to the respiratory embarrassment, the patient was electively intubated. Conservative management was provided. Emphysema resolved within 24 hours after the accident. Discussion. Various theories have been outlined in literature, like Mackler effect, Crampton theory and ball-valve mechanism. In our case, it was difficult to apply any of these theories to confirm the diagnosis. Conservative management is still used in the treatment of surgical emphysema. Conclusion. Surgical emphysema is a common encounter in trauma practice, and its identification is essential to rule out any emergency causes which may lead to respiratory distress

was given; the patient underwent plain computed tomography (CT) of the brain which showed no abnormalities, facial bone/sinus fractures or parenchymal bleed.
The patient was followed up, and within one hour she developed swelling of the whole face, extending from the upper lip to the hair line (frontal) bilaterally. Crepitus and crackles were noted. The swelling progressed to involve the whole face later (Fig. 1, 2), however, it did not extend to the neck. Chest X-ray was performed to exclude pneumothorax ( Fig. 3) and showed normal result. ENT consul-tation was arranged, the doctor revealed no abnormalities and recommended conservative management. The patient was subjected to CT again, and air-filled space was noted extending from parietal region to the lower border of mandible (Fig. 4). There was no respiratory compromise or  breathlessness, and saturation was at 95% at room air. In view of the increasing emphysema, trachea was electively intubated. The patient was closely observed and was kept with head-end elevation. She was transferred to surgical intensive care unit and was closely monitored. Next day morning, resolution of the emphysema was seen, and complete resolution was observed on day 2 of admission ( Fig. 5, 6). The patient was discharged, and follow-up within 1 month revealed no abnormalities and normal facial contour.
Discussion. Mackler effect of surgical emphysema following blunt trauma has been approved and accepted by many researchers. But the same effect cannot be applied in our case, since there was blunt trauma with no evidence of fracture (Fig. 3). Crampton in his paper described a 'ball-valve' mechanism provided by bandage application and mobilization during CT procedure in case of injury, and also discussed bandaging of the head over the laceration without suturing that could have caused the air to get trapped resulting in subcutaneous emphysema [3]. But the same ball-valve mechanism [4,5] described for extremities has not been reported for the scalp till now.
One such case report states that the use of hair coloring agent acted as reaction agent leading to formation of subcutaneous emphysema of the scalp, which later on resolved spontaneously [6].
The scalp, as we know, is composed of five layers forming the acronym 'SCALP' (the skin, connective tissue, epicranial aponeurosis, loose areolar tissue, and pericranium), tightly adhered to each other, except between the loose areolar tissue and the pericranium [7]. Hence the laceration over the scalp would have been deep enough to dislodge the first 4 layers resulting in air getting trapped.
The authors' observations in this case would be the depth of laceration in the scalp which eventually resulted in dislodgement of first 4 layers, and the positioning and free movement of the patient in the trauma care unit, resulting in air insufflation. We hypothesized that a mechanism like 'trap-door' effect would have occurred, which resulted in the move of air in the scalp down up to mandible and did not let the air out. The other 4 layers of the scalp are thick, and this can confirm this hypothesis. The emphysema was observed clinically starting from the scalp and down below.
Various management plans for subcutaneous emphysema proposed by different authors are available in literature consisting of multiple stab incisions, intercostal drains, subcutaneous drains [8]. But there are no trials to prove the effectiveness of one option over the others till now. Due to the benign nature of the emphysema, the authors' recommendation is to provide careful observation, and no intervention is required for the condition as such, unless any respiratory compromise occurs. It is quite mentionable that non-infectious etiology in cases of surgical emphysema should be ruled out, as the treatment protocols differ drastically. In this case it was ruled out by culture and sensitivity tests.
Conclusion. Surgical emphysema is a benign self-limiting condition which is very common in trauma care, and necessary knowledge of it is mandatory for all surgeons, in finding out the underlying cause and taking necessary actions to avoid the progression of the condition. This case report gives a simple understanding of a complex presentation of surgical emphysema.

Conflicts of interest.
The authors and co-authors declare no potential conflict of interest in research, publishing and presentation of this article. The conference does not restrict the publication of the study in any journal.