The patient (CR) is a 16-year-old Caucasian male with a past medical history significant for asthma (no prior intubations or hospitalizations). CR’s mother called her pediatrician’s office on a Friday morning complaining that her son had mild facial swelling in bilateral cheeks and neck. She reported: no fevers, no dyspnea, no drooling, no difficulty tolerating PO intake, and no URI symptoms. In fact, other than the swelling which had gotten worse over the past 24 hours, he seemed to be in great health. Both the pediatrician and mother agreed that she should continue to watch CR closely, but there was no need to come in to the office emergently.
CR’s mother called her pediatrician’s office again later in the afternoon. She reported that the facial swelling was looking worse to her. She also forgot to mention earlier that she had noticed a change in CR’s voice over the past 2-3 days. The pediatrician was concerned that this could be a presentation of Mumps…but she was closing for the day, so she asked the mother to take CR to a local urgent care clinic. CR’s mother agreed and they presented at the clinic where a CXR was done. No radiologist was on hand and the CXR looked “abnormal”, so they were referred to the emergency department.
On presentation, CR was noted to have normal vital signs; afebrile. CR was labeled as a level 2 acuity and was placed in a room. On evaluation (HPI): 16-year-old M who presents c/o facial swelling and “squishiness” that extends into his neck and chest. First noted sxs 2-3 days ago and has continued to worsen since onset. Pt denies resp complaints (no dyspnea, no SOB). Denies recent trauma. Denies fevers. Assoc sxs include “voice change”. Denies URI sxs, cough. Pt does report an acute choking episode 5-6 days ago…lasted several seconds and then was able to swallow his food. No difficulty or pain after episode. Pt adamantly denies any drug use (with mother out of the room). Pt does work with mulch for his summer job.
Physical exam was significant for a notable voice change. Oropharynx was clear. CR was noted to have swollen cheeks with palpable crepitus along bilateral sides of neck and under his mandible. This crepitus extended down through the chest wall and was palpable bilaterally to the level of the 12th ribs (positive “rice-crispy sign”). Cardiac exam showed normal heart sounds with no audible “crunch” (negative Hamman sign). CR had clear breath sounds, no wheezing, no noted retractions.
A lateral and PA CXR were immediately ordered (see images) and the diagnosis was made: Pneumomediastinum. CR was started on high flow oxygen (to help with reabsorption) and the decision was made to give a dose of prophylactic antibiotics in the ED in case of “itis”. CR was admitted to the PICU for an observation period. During his hospital stay he underwent an esophagogram to rule out esophageal tear: negative study.
FINDING: Pneumomediastinum, also known as the “Macklin Effect” was first described in 1939. Pathophysiology: In cases not due to primary trauma or esophageal tear, alveolar wall rupture occurs secondary to high intra-alveolar pressure caused by artificial ventilation, coughing, straining, a prolonged Valsalva maneuver, retching, labor, scuba diving (barotrauma) or inhalation of alkaloidal cocaine…thus allowing leakage of air into the perivascular connective tissue. This air will then track along tissue planes. Pneumomediastinum is usually a benign self limiting condition that occurs most frequently in young healthy males. Patients should be worked-up to look for the “air leak source” and admitted for an observation period. Physicians should note that subcutaneous palpable air is the most consistent physical exam finding. In our patient, it was felt that the etiology of his pneumomediatstinum was due to his acute choking episode 5-6 days prior to his presentation.