Radiology Cases in Pediatric Emergency Medicine
Volume 1, Case 7
Robert J. Butts, MD
Kapiolani Medical Center For Women And Children
University of Hawaii John A. Burns School of Medicine
A 20 year old male presents to the emergency
department at 2:15 a.m. after awakening late at night
with difficulty breathing. He initially experienced severe
difficulty, but upon arrival in the ED he reported some
improvement. He had some mild chest pain. He was
not very communicative and declined to describe the
chest pain further. He was brought in by his father who
noted he was behaving differently than usual. The
patient admitted to smoking crack cocaine on the day
prior to arrival. He denied other illicit drug or alcohol
use. His father was aware of the substance abuse and
attributed his unusual behavior to this.
Exam: VS T36.6, P82, R22, BP 144/84. His
oxygen saturation in room air was 100%. He was
awake and alert, although he was noted to exhibit a
somewhat flattened affect. He ambulated well. He
exhibited a dry cough. Pertinent physical findings
revealed clear lung fields. Auscultation of the heart
revealed normal S1 and S2 with what was thought to be
a friction rub. This was described as a fine grating
sound similar to the dehiscence of Velcro. It was very
brief and was noted to occur regularly with each heart
beat in systole. There was no chest wall tenderness.
His peripheral pulses were good. His color and
perfusion were good. The remainder of the exam was
unremarkable. A normal EKG was obtained. A chest
radiograph was obtained to look for evidence of
View CXR: AP view
View CXR: Lateral view
The patient returned from the Imaging department
40 minutes later. His CXR showed no cardiomegaly.
His aortic shadow appeared to be normal. At this time,
his symptoms had spontaneously resolved. He was no
longer short of breath. His chest pain had also
resolved. His vital signs showed improvement. Cardiac
auscultation at this time was normal. The fine grating
sound could no longer be heard. The patient was
discharged at 3:30 a.m. in good condition with a
diagnosis of transient shortness of breath with a history
of substance abuse. He was advised to rest and refrain
from further drug use. He was instructed to return if his
Later that morning, a radiologist reading his CXR
noted a pneumomediastinum. On the PA film, air is
seen dissecting along the superior mediastinum
bilaterally, and shadows consistent with subcutaneous
emphysema were noted apically over the left lung.
Note the vertical air densities extending upward from
the mediastinum more noticeable on the left than on the
right. There is also air superimposed over the inferior
aspect of the aortic arch.
More impressively, the lateral radiograph revealed
mediastinal air trapping with thymic demarcation. Note
the oblique air space present above (anterior and
superior to) the heart. You may have to adjust the
brightness and contrast controls on your monitor to
visualize these findings. There are also vertical air
densities outlining the trachea.
The patient was called to notify him of the findings.
His symptoms had resolved. He was instructed to
follow up with his private physician.
1. The abuse of crack cocaine has become
epidemic among adolescents in many areas. The
possibility of drug abuse in any adolescent who arrives
with chest or pulmonary complaints should be
2. Abnormal chest radiographs are quite common in
cocaine users admitted with respiratory complaints,
ranging from 12-55% (2). Both pneumomediastinum
and pneumothorax are relatively common after illicit
cocaine use, and the incidence is higher for those who
smoke crack cocaine, a relatively pure, extremely
addictive, intensely euphoric alkaloid form of cocaine.
Of those with pneumomediastinum, one series reported
73% with detectable subcutaneous emphysema and
50% with Hamman's sign, an unusual systolic crunch
heard over the cardiac apex and the left sternal border
The mechanism of air leaks is felt to be related to
exertional inhalation with Valsalva maneuvers. Drug
users do this to accomplish the highest delivery of drug
to the bloodstream. Irritants in the inhalant and the
higher temperatures of the inhalant may induce reflex
coughing, resulting in even greater intrathoracic
pressure surges. In most cases, air is allowed into the
mediastinum by spontaneous rupture of distended
alveoli into the pulmonary vascular sheath (4).
3. The peculiar crackling, bubbling, or churning
sounds heard usually during systole (Hamman's sign)
are considered, by some, to be pathognomonic for
mediastinal emphysema, and were first described in
1945 by Hamman (5), who also attributed interstitial
emphysema to trauma, increased intrapulmonary
pressure (Valsalva maneuvers and cough), or
spontaneous rupture of alveoli. Hamman's sign is often
noted to be transient, as in this case. Hamman's sign
has also been well described with isolated
pneumothoraces and may represent free pleural air
cyclically channeled through a lung fissure (6).
4. Retrospective reviews of young children with
tracheobronchial foreign body aspiration have revealed
a relatively high frequency of pneumomediastinum on
initial chest radiographs. The radiographic finding of
pneumomediastinum should lead to the consideration of
foreign body aspiration in any child in a high risk age
5. Pneumomediastinum is seen not uncommonly as
a relatively late complication of cystic fibrosis (9), and if
noted in any steroid-dependent child with unexplained
fevers, esophageal rupture should be considered (10).
Rarely, pneumomediastinum may signal
tracheobronchial disruption in any patient with blunt
thoracic trauma (11).
6. Pneumomediastinum and/or pneumothorax
should be considered as an etiology for respiratory
complaints or chest pain in any young person whose
daily activities may include an unusual frequency of
Valsalva maneuvers or increased intrathoracic
pressure. Examples include a young trombonist (12)
and a Chinese martial arts expert (13).
7. Complete recovery within days is expected for
drug- and Valsalva-related pneumomediastinum.
1. Luque MA, Cavallaro DL, Torres M, Emmanual
P, Hillman JV. Pneumomediastinum, pneumothorax,
and subcutaneous emphysema after alternate cocaine
inhalation and marijuana smoking. Pediatric
Emergency Care 1987:3(2): 107-109.
2. McCarroll KA, Roszler MH. Lung disorders due
to drug abuse. Journal of Thoracic Imaging
3. Seaman ME. Barotrauma related to inhalational
drug abuse. Journal of Emergency Medicine
4. Brody SL, Anderson GV, Gutman JB.
Pneumomediastinum as a complication of crack
smoking. American Journal of Emergency Medicine
5. Hamman L. Mediastinal emphysema. Journal of
the American Medical Association 1945;128:1-6.
6. Baumann MH, Sahn SA. Hamman's sign
revisited. Pneumothorax or pneumomediastinum?
7. Burton EM, Riggs W Jr, Kaufman RA, Houston
CS. Pneumomediastinum Caused by Foreign Body
Aspiration in Children. Pediatric Radiology
8. Ramadan HH, Bu-Saba N, Baraka A, Mroueh S.
Management of an Unusual Presentation of Foreign
Body Aspiration. Journal of Laryngology and
9. Grum CM, Lynch JP. Chest radiographic
findings in cystic fibrosis. Seminars in Respiratory
10. Klygis LM, Jutabha R, McCrohan MB,
Vanagunas AD. Esophageal Perforations Masked by
Steroids. Abdominal Imaging 1993:18(1):10-12.
11. Baumgartner F, Sheppard B, deVirgilio C, Esrig
B, Harrier D, Nelson RJ, Robertson JM. Tracheal and
Main Bronchial Disruptions After Blunt Trauma. Annals
of Thoracic Surgery 1990;50(4):569-574.
12. Ito S, Takada Y, Tanaka A, Ozeki N, Yazaki Y.
A case of spontaneous pneumomediastinum in a
trombonist. Kokyu To Junkan 1989;37(12):1359-62.
13. Yoneyama H, Matsushima T, Nakamura J,
Yano T, Adachi M, Tano Y. Two cases of spontaneous
pneumomediastinum due to Xiao-lin Temple boxing
vocal exercise. Nippon Kyobu Shikkan Gakkai Zasshi
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