(Chest. 2001;120:649-651.)
© 2001
American College of Chest Physicians
The White Chest*
Iain D. Lyburn, MB;
William C. Torreggiani, MB;
Alison C. Harris, MB and
Charles V. Zwirewich, MD
*
From the Department of Radiology, Vancouver General Hospital, Vancouver, BC Canada.
Correspondence to: William C. Torreggiani, MB, Department of Radiology (Abdominal Division), Vancouver General Hospital, 899 West 12th Ave, Vancouver, BC Canada V5Z 1M9; e-mail: williammart{at}hotmail.com
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Introduction
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A 39
-year-old man underwent distal gastrectomy and vagotomy for refractory
peptic ulcer disease. The surgery and initial postoperative
period were uneventful. Forty-eight hours after surgery, he developed
progressive respiratory failure and ARDS, necessitating admission to
the ICU and mechanical ventilation. Severe hypoxemia persisted despite
the use of high ventilatory pressures and a fraction of inspired oxygen
of 0.8 to 1.0. A supine anteroposterior chest radiograph was taken
later that day (Fig 1
).
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What is the diagnosis?
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Diagnosis: Partial liquid ventilation with perflubron
Perflubron is a synthetic liquid ventilation agent used as
an adjunct to positive pressure ventilation in selected patients with
severe respiratory failure.1
This radiopaque liquid
improves pulmonary gas exchange and lung compliance, and has
characteristic and dramatic imaging appearances.
After discontinuation of treatment, perflubron gradually clears from
the lungs over several days (Fig 2
,
3
). An abdominal CT performed 4 days after administration of perflubron
demonstrates the markedly hyperattenuating agent in the dependent
portions of the lower lobes (Fig 4
). The patient’s oxygenation and respiratory failure gradually
improved, and after a prolonged hospitalization, he was discharged
without supplemental oxygen.
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Figure 4.. CT scan 10 days following perflubron
administration. Residual agent is present in a symmetric, lower-lobe
distribution. The opacified portions of lung parenchyma demonstrated
extremely high attenuation values (1,103 Hounsfield units).
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Discussion
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Despite advances in intensive care medicine, the ARDS carries a
significant mortality rate of up to 90% in severely ill patients.
Vigorous intensive care treatment regimes and techniques of ventilatory
support, including liquid ventilation, are continuing to be
developed.2
Perflubron (perfluoro-octylbromide) is a
clear, inert, liquid fluorinated hydrocarbon rendered radiopaque by the
presence of a single bromide atom. The oxygen- and carbon
dioxide-carrying capacities of perflubron are 20 times and 60 times
greater than water, respectively.2
By displacing
the intra-alveolar exudate in patients with ARDS, perflubron aids
alveolar recruitment, reduces atelectasis and
consolidation,3
and improves oxygenation of the lung. By
reducing alveolar surface tension, perflubron also improves pulmonary
compliance. The drug is used to facilitate physiologic gas exchange in
patients in whom conventional ventilatory support techniques have
failed.2
3
There are currently two methods of liquid ventilation: total and
partial. Total liquid ventilation with perflubron-filled lungs is
performed with a specialized tidal liquid ventilator. In partial liquid
ventilation, perflubron is administered in small increments through an
endotracheal tube until a meniscus is present in the tube at the level
of the sternum with the patient in the supine position.2
A
standard gas ventilator is then used to deliver oxygen to the static
liquid column within the lungs.
Following administration of perflubron, the lungs are generally
rendered completely radiopaque on the frontal chest radiograph. Lack of
opacification of a pulmonary lobe is usually due to mucous plugging of
a lobar bronchus.3
The normal distribution of perflubron
during liquid ventilation is typically symmetrical and gravity
dependent.3
On CT images, perflubron is distributed in a
dense, homogeneous pattern immediately after administration. Over time,
the intra-alveolar deposits become more patchy as the agent begins to
vaporize.4
Clearance of perflubron occurs predominantly by
evaporation through the endotracheal tube, with minimal systemic
absorption or lymphatic uptake.2
Clearance occurs more
rapidly from the anterior portions of the lung, with
approximately one third of the administered dose remaining after 1
week. A minimal residual is usually detectable by the third week after
administration.3
Failure of perflubron to clear from a
specific lobe suggests endobronchial obstruction, typically from a
mucous plug.3
Dense extrapulmonary perflubron may be seen
in mediastinal, supraclavicular, axillary, and retroperitoneal lymph
nodes when small amounts of the drug are phagocytosed by the lymphatic
system.4
These lymphatic deposits may persist for months
after perflubron has cleared from the lungs.
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Figure 3.. Chest radiograph at 10 days demonstrates further
clearing with some residual perflubron distributed in the lower lobes.
A left thoracostomy tube was inserted subsequent to the development of
a small pneumothorax that was believed to be secondary to positive
pressure ventilation.
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Received for publication July 7, 2000.
Accepted for publication August 8, 2000.
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References
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Leach, CL, Fuhrmann, BP, Morin, FC, et al (1993) Perflubron-associated gas exchange (partial liquid ventilation) in respiratory distress syndrome: a prospective, randomised, controlled study. Crit Care Med 21,1270-1278[ISI][Medline]
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Shaffer, TH, Wolfson, MR, Clark, LC, Jr (1992) Liquid ventilation: state of the art review. Pediatr Pulmonol 14,102-109[ISI][Medline]
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Kazerooni, EA, Pranikoff, T, Cascade, PN, et al (1996) Partial liquid ventilation with perflubron during extracorporeal life support in adults: radiographic appearance. Radiology 198,137-142[Abstract/Free Full Text]
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Meaney, JF, Kazerooni, EA, Garver, KA, et al (1997) Acute respiratory distress syndrome: CT findings during partial liquid ventilation. Radiology 202,570-573[Abstract/Free Full Text]
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Introduction
What is the diagnosis?
