Case Report

Respiration 2000;67:98–100 Received: November 20, 1998 Accepted after revision: April 6, 1999

Trepopnea due to Recurrent Cancer

Yoshio Tsunezuka a Hideo Sato a Toshihide Tsukioka a Hiroshi Shimizu b

Departments of aThoracic Surgery and bRadiology, Ishikawa Prefectural Central Hospital, Kanazawa, Japan

Key Words that patients with unilateral lung disease have lower oxy- Pulmonary artery stenosis W Lung cancer W Stent W gen tension when they lie on the lateral side with the Trepopnea affected lung down. We report an interesting case of lung cancer with a complaint of trepopnea, and will discuss the unique physiology of this case. Abstract Trepopnea is a condition whereby may be comfortable in one position but difficult or labored in Case Report another. A unique case with trepopnea due to recurrent lung cancer with right main pulmonary artery stenosis A 57-year-old male patient developed progressive shortness of and left main obstruction is presented. The breath over a 3-month period. The symptom was most severe in the right lateral position, but improved when lying on his left side. He patient had developed trepopnea 3 months earlier, but noted a sensation when lying in the supine or right lateral developed shortly before he was admitted to position and dyspnea when he visited the emergency department of our hospital. An emergent wall stent implantation was Ishikawa Prefectural Central Hospital. Three years earlier, he had performed via the right femoral vein in the sitting posi- undergone a left lower lobectomy for poorly differentiated squamous tion with the patient’s leg stretched out. The symptoms cell carcinoma of the lung (pT1N0M0). Physical examination on admission revealed tachycardia and . The breath sounds and respiratory function improved after stent implanta- were diminished with a coarse crackle over the left upper lung field. tion. The second heart sound was split. Arterial blood gas analysis in the Copyright © 2000 S. Karger AG, Basel sitting position demonstrated PaO2 of 68.5 mm Hg and oxygen satu- ration of 92.4% in room air, which improved to 90.4 mm Hg and 96.0% in 100% oxygen. In the supine position or right lateral posi- tion, oxygen saturation rapidly decreased to 70% even when 100% Introduction oxygen inhalation was given, so he could not lie down. Especially in the right lateral position, the patient complained about severe dys- Trepopnea is an uncommon pattern of breathlessness pnea, oxygen saturation decreased to less than 50% when 100% oxy- that occurs exclusively in a lateral body position. Origi- gen inhalation was given. Respiratory function studies revealed nally described in patients with heart disease, it is thought obstructive change with FVC of 3.22 liters (predicted 3.43), FEV1.0/ FVC ratio of 56.2% (predicted 69.8) and MMF of 1.01 liters/s (pre- to result from distortion of the great vessels in one posture dicted 3.51 liters). Chest X-ray suggested stenosis of the left main versus the other. It has also been described in patients bronchus. Enhanced helical computed tomography (CT) of the chest with pulmonary disease and related to the observation in the left hemilateral position showed right main pulmonary artery

© 2000 S. Karger AG, Basel Yoshio Tsunezuka, MD, PhD ABC 0025–7931/00/0671–0098$17.50/0 Department of Thoracic Surgery Fax + 41 61 306 12 34 Ishikawa Prefectural Central Hospital E-Mail [email protected] Accessible online at: Kanazawa, 920-8530 (Japan) www.karger.com www.karger.com/journals/res Tel. +81 76 237 8211, Fax +81 76 238 2337, E-Mail [email protected] Fig. 1. Computed tomography of the chest shows right main pulmonary and left main bronchial stenosis caused by mediastinal re- currence of lung cancer.

Fig. 2. Computed tomography of the chest after stent implantation and radiation thera- py showed the pulmonary artery and the bronchus are open.

and left main bronchus stenosis (fig. 1). These findings indicated Discussion recurrent lung cancer with mediastinal lymph node metastasis. ECG demonstrated no abnormalities other than sinus tachycardia and pul- The term ‘trepopnea’, first used to express difficulty in monary P wave. A metallic expandable stent was inserted into the main right pulmonary artery via the right femoral vein in the sitting breathing while lying on one side, is derived from the position because he could not remain in the supine position due to Greek words ‘trepin’, to turn, and ‘pnea’ to breathe [2]. In dyspnea. He sat in a reclining chair and his right leg was stretched to general, trepopnea is a striking symptom with marked establish a flat right inguinal region. The technique of stent implanta- dyspnea and oxygen desaturation in the affected lateral tion was previously described in detail [1]. The procedure was per- position. The present case is interesting because the formed under local anesthesia. After achieving venous access, hepa- rin was administered (50 U/kg) intravenously, and the activated clot- patient’s was aggravated in the right ting time maintained above 250 s. A guidewire with a polyethylene lateral position and improved when lying on the left side, angiographic catheter (JB-1-5.0B, 100 cm, Cook, USA) was placed in despite severe left main bronchus stenosis. the proximal right pulmonary artery over the stenotic segment after This case exhibited mediastinal lymph node swelling pulmonary artery angiography. A wall stent with a delivery device due to lung cancer metastasis. In addition to the left main system, 50 mm long, 10 mm in diameter (8 Fr, Schneider, USA) was used. Soon after stent implantation, symptoms improved and he bronchus stenosis, the right main pulmonary artery steno- could lay in the supine position and sleep well 3 days later. Five days sis induced severe dyspnea due to ventilation/perfusion following implantation, bronchoscopic examinations revealed 80% disequilibrium. The result was that the patient felt a chok- obstruction of the left main bronchus due to lung cancer. Histological ing sensation especially when lying on his right side examinations of biopsy specimens obtained using a bronchofiber despite the left pulmonary disease. In general, trepopnea revealed squamous cell carcinoma corresponding to primary lung cancer that had been resected 3 years earlier. One week later, he is attributed to heart disease, and has also been found in underwent radiation therapy with a total of 72 Gy for interbronchial patients with pulmonary disease [3–5]. Blood flow to the cancer of the left main bronchus and mediastinal metastasis. After left pulmonary artery was clearly inhibited in the right lat- radiation therapy, the left main bronchus was open and stenosis of eral position due to gravity because the right main pulmo- the right main pulmonary artery was patent with the stent (fig. 2). nary artery was stenotic. This finding demonstrates that Respiratory function studies revealed improvement with FVC of circulatory dynamics strongly influence respiratory symp- 3.22 liters, FEV1.0/FVC ratio of 78.9% and MMF of 2.47 liters/s. Two months after discharge, the patient did not complain of dyspnea toms, such as dyspnea. We thought that the symptom was and could sleep well in the supine and right lateral positions. due to the stenotic right pulmonary artery unable to

Trepopnea due to Recurrent Lung Cancer Respiration 2000;67:98–100 99 accommodate the increased flow to the right lung caused gradually, and disappeared 3 days later. These findings by the hypoxic vasoconstriction of the left lung and the may have been due to the large volume of right-to-left consequent shunt to the right lung. shunting already presented in the left lung and the func- The symptoms in our patient did not improve imme- tional inability of the right pulmonary vessels to keep up diately after stent implantation. The symptom reduced with the rapid increase in blood flow.

References 1 O’Laughlin MP: Catheterization treatment of 4 Mercho N, Stoller JL, White RD, et al: Right- stenosis and hypoplasia of pulmonary arteries. to-left interatrial shunt causing after Pediatr Cardiol 1998;19:48–56. pneumonectomy: A recent experience and 2 Wood FC: Trepopnea. Arch Intern Med 1959; diagnostic value of dynamic magnetic reso- 104:966. nance imaging. Chest 1994;105:931–933. 3 Winters WL Jr, Cartes F, McDonough M, et al: 5 Alfaifi S, Lapinsky SE: Trepopnea due to inter- Venoarterial shunting from inferior vena cava atrial shunt following lung resection. Chest to left atrium in atrial septal defects with nor- 1998;113:1726–1727. mal heart pressures. Am J Cardiol 1967;19: 293–300.

100 Respiration 2000;67:98–100 Tsunezuka/Sato/Tsukioka/Shimizu