ORIGINAL ARTICLE
Effects of Fluid Resuscitation on Cardiovascular Performance After
Posttraumatic Pneumonectomy
Ruy J. Cruz, Jr., MD, PhD, Jeane M. Tsutsui, MD, PhD, Paulo Magno, MD, Wilson Mathias, Jr., MD, PhD,
and Mauricio Rocha-e-Silva, MD, PhD
Background: Several factors have been implicated in the high-mortality rate
of posttraumatic pneumonectomy. In this study, we evaluated the hemody-
namic and echocardiographic changes induced by pneumonectomy and fluid
resuscitation after hemorrhagic shock.
Methods: Fourteen dogs were bled to a target mean arterial pressure of 40
mmHg. The animals were assigned to two groups: control (no fluid resuscitation)
and lactated Ringer’s (3 shed blood volume). The left pulmonary hilum was
cross clamped, and the animals were observed for 60 minutes. Systemic
hemodynamics was evaluated using Swan-Ganz, arterial catheter, and ultrasonic
flow probe. Systemic O
2
-derived variables were calculated. Ejection fraction
was determined by two-dimensional echocardiography.
Results: Fluid resuscitation improved the mean arterial pressure and sys-
temic oxygen delivery. After pneumonectomy, no significant increase in
right ventricular pressure was observed in the LR group. No signs of major
ventricular dilation or changes in arterial oxygenation were observed.
Conclusion: Our data suggest that pneumonectomy is not associated with
early pulmonary hypertension; gentle fluid resuscitation improves cardiovas-
cular performance and is not associated with an increase in right ventricular
pressure.
Key Words: Trauma, Hemorrhagic shock, Hypovolemia, Pneumonectomy,
Echocardiography, Pulmonary hypertension, Right ventricular dysfunction.
(J Trauma. 2010;68: 604 – 610)
T
he majority of pulmonary injuries can be managed gen-
erally by a simple tube thoracostomy; however, 9% to
20% of blunt or penetrating thoracic trauma victims require
thoracotomy for bleeding control, and up to 30% of these
patients require some type of lung resection.
1–3
Lung resec-
tions in the trauma setting are usually achieved with lung-
sparing techniques, such as tractotomy, wedge resections, and
nonanatomic lobectomy.
4–8
In the past few decades, the wide-
spread use of staplers resulted in a significant improvement in
survival, minimizing the intraoperative bleeding, surgical time,
and the amount of lung parenchyma resected. Several studies
have shown that the increase in mortality and morbidity corre-
lates with the extension of pulmonary resection.
9,10
Although economical resection is always advisable,
some patients sustained complex hilar or bronchial injuries
requiring an urgent pneumonectomy. The lowest reported
mortality rates after traumatic pneumonectomy range from
50% to 80%, with several series reporting a 100% death
rate.
2,3,11
Several factors have been associated with the high
mortality of this complex and sometimes challenge proce-
dure, including severe hypovolemia, hypoxemia from pri-
mary and secondary injury, and right ventricular failure.
Concerns about pulmonary hypertension after lung re-
section in trauma patients have been raised, but the impact of
pneumonectomy in the regional and systemic hemodynamic
has not been well established. In addition, neither experimen-
tal nor clinical studies have evaluated the occurrence of
cardiac dysfunction after posttraumatic pneumonectomy.
Therefore, we designed an experimental protocol to investi-
gate the immediate hemodynamic and echocardiographic
changes induced by pulmonary hilum cross clamping after
hemorrhagic shock. In addition, we sought to evaluate the
effects of early fluid resuscitation on cardiovascular perfor-
mance in this, unusual but often, fatal clinical problem.
MATERIALS AND METHODS
The experimental protocol was approved by the Insti-
tutional Review Board, in adherence with the Principles of
Laboratory Animal Care formulated by the National Society
for Medical Research and the Guide for the Care and Use of
Animals by the National Institutes of Health.
Animals and Surgical Procedures
Fourteen male mongrel dogs weighing 18.4 kg 0.6
kg were fasted for 12 hours before the study, with free access
to water. Anesthesia was induced with an intravenous injec-
tion of 0.1 mg/kg of morphine sulfate followed by 25 mg/kg
of pentobarbital sodium; the animals were then placed on a
warming blanket to maintain normothermia throughout the
experiment. After endotracheal intubation, the animals were
mechanically ventilated with a 0.7 fraction of oxygen in-
spired, at a tidal volume of 15 mL/kg. The ventilator was
adjusted to achieve an initial arterial PCO
2
between 35 mmHg
and 45 mmHg. Additional doses of 2 mg/kg pentobarbital
were used whenever required. A urinary bladder catheter was
placed for urinary drainage. During surgical preparation, the
animals received lactated Ringer’s (LR) solution at a rate of
20 mL/kg/h to compensate for fluid losses, including imper-
ceptible perspiration. The right common femoral artery and
Submitted for publication November 13, 2008.
Accepted for publication November 6, 2009.
Copyright © 2010 by Lippincott Williams & Wilkins
From the Research Division (R.J.C., M.R.S.) and Echocardiography Service
(J.M.T., P.M., W.M.J.), University of Sa ˜o Paulo Medical School, Brazil.
Address for reprints: Ruy J Cruz, MD, PhD, Department of Surgery, University of
Pittsburgh, UPMC Montefiore, South, 3459 Fifth Avenue, Pittsburgh, PA
15213-3442; email: cruzrj@upmc.edu.
DOI: 10.1097/TA.0b013e3181ce6976
604 The Journal of TRAUMA
®
Injury, Infection, and Critical Care • Volume 68, Number 3, March 2010