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Nontraumatic hemothorax is a rare cause of postpartum respiratory distress. We present a case of massive spontaneous hemothorax, which presented during the immediate postpartum period and was initially treated as pulmonary embolism. Further investigation revealed a tiny lung nodule: although pulmonary arteriovenous malformation was considered, the imaging appearances tended to counter this interpretation. Eventually, in the absence of another cause for spontaneous hemothorax, on either clinical or imaging grounds, we diagnosed spontaneous arteriovenous malformation. Its management is discussed herein.
Nontraumatic hemothoraces are distinctly uncommon. They may result from a variety of causes, and in some patients the cause can remain unknown even after exploratory thoracotomy.1 We submit a case of spontaneous massive hemothorax that presented during the immediate postpartum period.
In December 2006, a 39-year-old woman, who had no significant medical history, presented with shortness of breath 6 days after a spontaneous vaginal delivery of her 4th child. The labor this time had been short, and the baby had been delivered easily over the course of 2 contractions, once full dilation had occurred. The postpartum period had been uncomplicated, and the woman was discharged on the 2nd day after delivery. She initially presented to our obstetric unit with dyspnea and a single episode of syncope. On clinical examination, the patient was pale and tachypneic and had an oxygen saturation level of 92% on room air. Air entry on the right side of the chest was absent. She was hemodynamically stable, and the remainder of the examination was unremarkable.
On the presumptive diagnosis of pulmonary embolism, the patient was given 15,000 IU of dalteparin in our obstetric unit. Subsequent to this, a chest radiograph showed complete opacification of the right hemithorax, with right-to-left mediastinal shift (Fig. 1). A full blood count revealed a hemoglobin level of 49 g/L and a platelet count of 381 × 109/L. The clotting screen and the biochemical analysis yielded essentially normal results. Computed tomography of the thorax showed the right pleural space to be filled with blood and revealed consequent compression atelectasis of the lung (Figs. 2 and and3).3). Because dalteparin had been administered, a hematology consultation was obtained before an intercostal drain was inserted. One hundred fifty units of protamine sulfate were administered in the hope of achieving at least partial reversal of the dalteparin. In the intensive care unit, a right-sided intercostal drain was inserted without complication, and a total of 3,800 mL of old blood was drained from the right pleural cavity. There was no subsequent clinical or imaging evidence of further blood loss. In total, 4 units of packed red blood cells were transfused.
The patient made an excellent recovery, and her intercostal drain was removed 72 hours after insertion. A follow-up, high-resolution computed tomographic scan of the chest, obtained before discharge, revealed 2 small dense opacities (maximum diameter, 2 mm) in the apical segment of the right lower lobe and in the posterior aspect of the middle lobe (Fig. 4). It was believed that these might represent small arteriovenous malformations; and in the absence of another cause for spontaneous hemothorax, on either clinical or imaging grounds, we diagnosed spontaneous arteriovenous malformation.
At her clinical follow-up 4 weeks after hospital discharge, the patient had made a complete recovery and was enjoying life with her new child to the full. No further active management is planned, although the patient will be monitored.
Spontaneous hemothorax may result from rupture of subpleural arteriovenous malformations.2 Pulmonary arteriovenous malformations (PAVMs) may be defined as direct communications between branches of a pulmonary artery and pulmonary vein, without an intervening pulmonary bed. These malformations are rare, and more than 80% are congenital.3 There is an association of PAVMs with Rendu-Osler-Weber syndrome (hereditary hemorrhagic telangiectasia).3,4
Pregnancy can increase the size of PAVMs, due in part to the increase in cardiac output and to hormonal change. Increased progesterone levels dilate the arteriolar smooth muscle, reducing resistance to blood flow through a pre-existing PAVM.3–5
Pulmonary arteriovenous malformations can be asymptomatic or can present with fatigue, exertional dyspnea, hemoptysis, and chest pain. Clinical signs include cyanosis, clubbing, telangiectasia, hemothorax, or a pulmonary bruit.3,6 Although a plain chest radiograph can aid diagnosis, the definitive diagnostic tests are contrast-enhanced computed tomography and pulmonary angiography.3 In pregnancy, PAVM can at first be mistaken for pulmonary embolism, which is a far more common cause of respiratory distress and reduced breath sounds upon clinical examination.3 However, in the presence of reduced breath sounds, hemothorax is suggested by reduced tactile vocal fremitus and by a stony dull percussion note. This diagnosis can be confirmed by hazy opacification upon chest radiography and by the appearance of fluid upon chest ultrasonography. Conversely, reduced tactile vocal fremitus accompanied by a resonant percussion note is suggestive of pneumothorax, which can be confirmed by a chest radiograph that shows a line of demarcation between lung tissue and chest wall. This line of demarcation, if present, is best seen at the apex.7 The presence of air and fluid in the chest (hydropneumothorax) can be diagnosed by succussion splash and by the presence of an air–fluid interface on the chest radiograph. Treatment is indicated in symptomatic patients and in those who display lesions greater than 2 cm in diameter on a plain chest radiograph.3 Initial management with therapeutic embolization may well be appropriate in pregnant patients who present with symptomatic PAVM.3–5 In patients who are hemodynamically unstable or in whom embolization has failed, open surgical resection of the PAVM has shown success.3–6
We have described a case of massive spontaneous hemothorax that presented during the immediate postpartum period, possibly secondary to a PAVM. In the differential diagnosis of dyspnea both in pregnancy and during the postpartum period, spontaneous hemothorax is an important albeit rare phenomenon that can be confused with pulmonary embolism. Had this patient continued to bleed, appropriate management would have included therapeutic embolization or, failing that, open surgical exploration and resection of the PAVM.
Address for reprints: Harikrishna Doshi, MCh, MRCS, Department of Cardiothoracic Surgery, Aberdeen Royal Infirmary, Aberdeen AB25 2ZN, UK. E-mail: ten.shn@ihsodh