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Year : 2022  |  Volume : 1  |  Issue : 1  |  Page : 36-38

An unusual case report of trepopnea in a patient with unilateral diaphragmatic palsy

Department of Anaesthesiology and Intensive Care, Maulana Azad Medical College, New Delhi, India

Date of Submission08-Apr-2022
Date of Acceptance27-Apr-2022
Date of Web Publication20-May-2022

Correspondence Address:
Dr. Sukhyanti Kerai
Department of Anaesthesiology and Intensive Care, Room No: 413, 4th Floor, B. L. Taneja Block, Maulana Azad Medical College, Bhadur Shah Zaffar Marg, New Delhi - 110 002
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jica.jica_11_22

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Trepopnea, a rare form of dyspnoea observed in lateral decubitus position is a crucial clue towards diagnosis. It indicates either cardiac or respiratory pathology that may warrant immediate attention. Usually, it has been reported the patient with congestive cardiac failure or diseased left lung who prefers the right lateral decubitus position. Only in a few cases with the unilateral lung disease it has been described. We present one such case report of trepopnea in a patient recovering from pneumonia was observed having trepopnea, which was later confirmed due to unilateral diaphragmatic palsy.

Keywords: Diaphragmatic, palsy, trepopnea, unilateral

How to cite this article:
Gupta D, Kerai S. An unusual case report of trepopnea in a patient with unilateral diaphragmatic palsy. J Ind Coll Anesth 2022;1:36-8

How to cite this URL:
Gupta D, Kerai S. An unusual case report of trepopnea in a patient with unilateral diaphragmatic palsy. J Ind Coll Anesth [serial online] 2022 [cited 2023 Sep 25];1:36-8. Available from: https://www.jicajournal.in//text.asp?2022/1/1/36/345593

  Introduction Top

Trepopnea is an uncommon form of orthopnea that occurs in one lateral decubitus only. We present an interesting case where trepopnea was initially thought to be due to cardiac cause and later found to be due to residual unilateral diaphragmatic paralysis (UDP).

  Case Report Top

A 75-year-old female was admitted to the intensive care unit (ICU) with a history of fever, cough with expectoration, and vomiting for 2 days and shortness of breath for 1 day. She had similar 2–3 episodes in the past few years, for which hospitalization was required. She was a known hypertensive on treatment with tablets aspirin, atorvastatin, metoprolol, and hydrochlorothiazide. There was a history of left cerebral infarct 10 years back with no apparent residual paralysis. On examination, she was conscious, oriented but dyspneic, even in propped up position, and was using accessory muscles of respiration. She had a heart rate of 110 beats/min, respiratory rate of 32 breaths/min, SpO2 of 84% on room air, and blood pressure of 92/52 mmHg on noradrenaline infusion at 0.4 μg/kg/min. The auscultation of the chest revealed bilateral crepitations. The high flow of warmed and humidified oxygen supplementation with the fractional inspired oxygen of 60% and flow rate of 50 l/min was started, after which the patient became comfortable and her SpO2 rose to 92%–93%. Samples for blood, sputum, and urine cultures; serum procalcitonin; lactate; and pro-BNP were sent, and she was started on fluid resuscitation and broad-spectrum antibiotics. X-ray of the chest showed right middle and lower zone consolidation, left perihilar infiltrates along with bilateral costophrenic angle blunting, and excessively raised right diaphragm [Figure 1]. Ultrasound of the chest ruled out pleural effusion. Transthoracic echocardiography showed an ejection fraction of 55% with no systolic or diastolic abnormalities. She was diagnosed as a case of lower respiratory tract infection with sepsis and septic shock. Gradually, the patient improved symptomatically; inotropes and high-flow oxygen therapy were weaned off in 5–6 days, and she maintained oxygen saturation of 91%–93% with the face mask. During her subsequent days of ICU stay, it was observed that she preferred lying on the right lateral decubitus (RLD) position. The SpO2 was noted to be higher by 3%–4% on right lateral positioning compared to left. On the elicitation of history, it was found that the patient even at home preferred lying on RLD for many years. Echocardiogram and serum pro-BNP levels were repeated and found to be within normal limits. The chest X-rays done had a persistent raised right diaphragmatic dome. The old chest X-ray done 2 months back was retrieved and demonstrated the same finding [Figure 2]. Her old documents of pulmonary function test showed a mild restrictive pattern with forced expiratory volume in 1 s/forced vital capacity of 77%. A pulmonologist's opinion was sought; ultrasound of the abdomen and contrast-enhanced computed tomogram of the chest were done, which ruled out additional abnormalities. Based on the history of repeated chest infections, history of stroke, and finding of raised right diaphragmatic dome, right-sided diaphragmatic palsy was suspected. The patient was offered a sniff test on fluoroscopy of the diaphragm for confirmation of unilateral diaphragmatic palsy, which revealed no movement of the right side. She was discharged from ICU 3 days later and was advised follow-up in the pulmonology outpatient department.
Figure 1: Chest X-ray of the patient in ICU. ICU: Intensive care unit

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Figure 2: Chest X-ray of the patient 2 years back

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  Discussion Top

Trepopnea is a rare form of orthopnea limited to one lateral decubitus position.[1] It is observed in many cardiac and unilateral lung conditions. In most of the unilateral lung conditions, trepopnea occurs when the patient assumes a lateral decubitus position on an affected lung side. This is because during spontaneous breathing, ventilation and perfusion preferentially distribute to dependent lung.[2] Hence, there are reports of patients affected with unilateral disease to prefer lateral position, with the unaffected side being dependent.

There are, however, few exceptions to this healthy lung down lateral positioning. Children, anesthetized paralyzed patients, some patients with chronic airflow limitation, and patients with massive unilateral pulmonary embolism have improved V/Q with diseased lung down in lateral position.[3] In patients with unilateral lung abscess and hemoptysis, lateral positioning with good lung down is contraindicated due to the risk of contamination of healthy lung.

In patients with UDP, trepopnea is reported with affected hemithorax nondependent, i.e., good lung down positioning.[4],[5] UDP is known to produce mild respiratory dysfunction as there is compensatory increased activity by remaining respiratory muscles including costal and crural diaphragm segments, parasternal, intercostals, and transversus abdominis muscles.[6] These patients typically during rapid eye movement sleep incur oxygen desaturation with unaffected diaphragm down as seen in sleep studies. This may be explained, as in these patients, healthy hemidiaphragm must generate the majority of inspiratory force. When an unaffected side is dependent, it is compressed by abdominal contents, and for generating inspiratory force, it has to counter higher force. The mobility of the chest wall is also restricted in the lateral decubitus position.[7] In our patient, trepopnea was observed even at awake state, probably due to her advanced age, weakness of compensatory respiratory muscles, and development of lung consolidation on the affected hemidiaphragm. Another possible mechanism for trepopnea in UDP is an excursion of mobile mediastinal structures to unaffected hemithorax as a result of the generation of different negative pressure during inspiration. This holds true especially in pediatric population where the mediastinal structures have enhanced mobility.[8]

In the present case, another differential diagnosis for trepopnea was congestive heart failure (CHF). CHF patients have been frequently observed to lie on RLD. This preference for positioning is a self-protective mechanism to attenuate increased sympathetic nervous modulation. The venous return is enhanced in RLD as the right atrium is lower position and right atrial pressure is elevated as a result of increased hydrostatic pressure. In addition, the hydrostatic pressure imposed on the left ventricle may be less in RLD compared to supine or left lateral decubitus. These lead to attenuation of dyspnea by decreasing pulmonary congestion.[9],[10] CHF in the above case was ruled out by normal biomarkers, echocardiography, and clinical improvement observed with a course of antibiotics.

  Conclusion Top

The occurrence of trepopnea is always pathological, signifying some underlying cardiac or pulmonary conditions. In unilateral lung diseases commonly, patient preference is lying down laterally with healthy lung down with few notable exceptions. Symptomatic UDP with trepopnea is a rare entity where the patient has a propensity toward lateral decubitus with dependent diseased lung. When observed in a patient with UDP, it provides a supportive clue to diagnosis along with other modalities.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Wood FC, Wolferth CC. The tolerance of certain cardiac patients for various recumbent positions (trepopnea). Am J Med Sci 1937;193:354-78.  Back to cited text no. 1
Gillespie DJ, Rehder K. Body position and ventilation-perfusion relationships in unilateral pulmonary disease. Chest 1987;91:75-9.  Back to cited text no. 2
Badr MS, Grossman JE. Positional changes in gas exchange after unilateral pulmonary embolism. Chest 1990;98:1514-6.  Back to cited text no. 3
Aslam F, Kolpakchi A, Musher D, Lu L. Unilateral diaphragmatic paralysis in a diabetic patient: A case of trepopnea. J Gen Intern Med 2011;26:555-8.  Back to cited text no. 4
Subramanyam P, Palaniswamy SS. Ventilation/Perfusion scan aids in the diagnosis of diabetes mellitus induced trepopnea due to isolated right phrenic nerve palsy. Indian J Nucl Med 2013;28:51-3.  Back to cited text no. 5
[PUBMED]  [Full text]  
Katagiri M, Young RN, Platt RS, Kieser TM, Easton PA. Respiratory muscle compensation for unilateral or bilateral hemidiaphragm paralysis in awake canines. J Appl Physiol (1985) 1994;77:1972-82.  Back to cited text no. 6
Baltzan MA, Scott AS, Wolkove N. Unilateral hemidiaphragm weakness is associated with positional hypoxemia in REM sleep. J Clin Sleep Med 2012;8:51-8.  Back to cited text no. 7
Robotham JL. A physiological approach to hemidiaphragm paralysis. Crit Care Med 1979;7:563-6.  Back to cited text no. 8
Leung RS, Bowman ME, Parker JD, Newton GE, Bradley TD. Avoidance of the left lateral decubitus position during sleep in patients with heart failure: Relationship to cardiac size and function. J Am Coll Cardiol 2003;41:227-30.  Back to cited text no. 9
Fujita M, Miyamoto S, Tambara K, Budgell B. Trepopnea in patients with chronic heart failure. Int J Cardiol 2002;84:115-8.  Back to cited text no. 10


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