AJR 2001; 176:428
© American Roentgen Ray Society
Trauma Cases from Harborview Medical Center |
Delayed Recognition of Diaphragmatic Rupture in a Patient Receiving Mechanical Ventilation
Yvonne M. Carter1,
Riyad C. Karmy-Jones1 and
Eric J. Stern2
1
Department of Surgery, Harborview Medical Center, University of Washington
School of Medicine, 325 Ninth Ave., Box 359728, Seattle, WA 98104-2499.
2
Department of Radiology, Harborview Medical Center, University of Washington
School of Medicine, Seattle WA 98104-2499.
Received August 28, 2000;
accepted after revision August 28, 2000.
This is another in the continuing series on radiology in trauma cases from
the Harborview Medical Center. Editors: Fred A. Mann, Eric J. Stern, and Lee
B. Talner.
Address correspondence to F. A. Mann.
Introduction
A 57-year-old man was involved in a head-on motor vehicle collision. His
injuries included closed head injury, pulmonary contusion, and fractures
involving the femur and pelvis. Acute intraabdominal hemorrhage was excluded
by diagnostic peritoneal lavage. Initial chest radiography showed
opacification of the left lower lobe with silhouetting of the left diaphragm
(Fig. 1A). The patient
developed acute lung injury that required ventilation with positive
end-expiratory pressure levels of 15-cm H2O for adequate
oxygenation. By the fourth hospital day the positive end-expiratory pressure
was removed. At that time, repeated chest radiography again showed dense
opacification of the left lower lung, but also showed interval malpositioning
of the nasogastric tube overlying the thorax, consistent with diaphragmatic
rupture with gastric herniation (Fig.
1B). At surgery, a 10-cm tear in the left hemidiaphragm with
herniation of the stomach and spleen was found and repaired.
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Fig. 1A. —57-year-old man with delayed diaphragm rupture. Initial chest
radiograph shows endotracheal intubation and nonspecific opacification of left
lower lobe with silhouetting of left diaphragm believed to represent
atelectasis.
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Fig. 1B. —57-year-old man with delayed diaphragm rupture. Follow-up
chest radiograph on fourth hospital day after positive end-expiratory pressure
was removed. Again note dense opacification of left lower lung, but now with
interval malpositioning of nasogastric tube (arrow) overlying thorax,
consistent with diaphragmatic rupture and gastric herniation.
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Diaphragmatic rupture is more likely due to blunt injury than from
penetrating trauma. The 0.8-1.6% incidence of diaphragmatic rupture in all
hospital admissions rises to 4.5% in severely injured patients
[1,
2]. Most penetrating injuries
are smaller than 2 cm. The larger tears associated with blunt injury result in
a higher incidence of visceral herniation in this group. Ruptures from blunt
mechanisms of injury often measure up to 10 cm in length, as in this case, and
present acutely with herniation
[2,
3].
The diaphragm separates the intraabdominal viscera, which are under
positive pressure, from the negative pressure within the thoracic cavity. At
rest, the pressure gradient varies from 7- to 20-cm H2O
[2]. Once a defect is created,
abdominal contents compelled by this pressure gradient can migrate through the
rent into the thorax. This migration is aggravated by any increase in
intraabdominal pressure such as that caused by bowel edema or retroperitoneal
hemorrhage. In the proper clinical setting, a chest radiograph showing a
nasogastric tube, with an otherwise expected course to the region of the
gastroesophageal junction, apparently misplaced over the thorax is nearly
pathognomonic of visceral herniation
[4]. Diaphragmatic eventration
can have a very similar and confusing appearance. Small lacerations are
believed to increase over time because of the radial tension in the central
diaphragm, with resultant late or delayed herniation usually within 2 years of
the injury [1,
2]. These do not represent late
occurrence of diaphragmatic breakdown, but only late recognition of what was a
small injury initially.
In this case, despite a large laceration of the hemidiaphragm, positive
pressure ventilation was enough to maintain the intraabdominal position of the
abdominal viscera. As positive intrathoracic pressure was decreased, the
abdominal contents herniated into the thorax. When there is an apparent
delayed-interval diaphragmatic rupture with intrathoracic visceral herniation,
the radiographic findings should be correlated with changes in ventilator
management for accurate interpretation.
References
-
Sharma OP. Traumatic diaphragmatic rupture: not an uncommon
entity—personal experience with a collective review of the 1980s.
J Trauma
1989;29:678
-682[Medline]
-
Reynolds MA, Richardson JD. Chest wall and diaphragm injuries. In:
Maul KI, Rodriguez A, Wiles CE, eds. Complications of trauma and
critical care. Philadelphia: Saunders, 1996:313
-324
-
Kearny PA, Rouhana SW, Burney RE. Blunt rupture of the diaphragm:
mechanism, diagnosis and treatment. Ann Emerg Med
1989;18:1326
-1330[Medline]
-
Gelman R, Mirvis SE, Gens D. Diaphragmatic rupture due to blunt
trauma: sensitivity of plain chest radiographs. AJR
1991;156:51
-57[Abstract/Free Full Text]
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Introduction
References
