A rare cause of non-cardiogenic pulmonary edemaKelly Zhang BS*, Talal Alzahrani MD*, Angela Ryan MD, Yasir Alfi MD, Jeffrey Zweig MD

The George Washington University, Division of General Internal Medicine Washington, DC

Learning Objectives

Identify patients with noncardiogenic pulmonary edema secondary to nephrotic syndrome (NS).

Describe the management of a patient with noncardiogenic pulmonary edema secondary to NS.

DiscussionRadiological/Pathological Studies

❖ Nephrotic syndrome is defined by proteinuria greater than 3.5 g/day, hypoalbuminemia less than 3.5 g/dl, and peripheral edema.

❖ It associated with risks of thrombosis, infection, and hyperlipidemia due to loss of plasma protein.

❖ The causes of nephrotic syndrome can be divided into two groups consisting of primary and secondary causes.

❖ The most common secondary cause is diabetic nephropathy.

❖ Nephrotic syndrome usually manifests by LE edema, weight gain, fatigue, and dyspnea secondary to pleural effusions.

❖ Several studies have shown patients with nephrotic syndrome do not develop non-cardiogenic pulmonary edema.

❖ However, there are two cases published in the medical literature of patients presenting with nephrotic syndrome and non-cardiogenic pulmonary edema.

❖ The first case describes a patient that was diagnosed with nephrotic syndrome and pulmonary edema due to bilateral renal artery stenosis. The second case details a patient with non-cardiogenic pulmonary edema and nephrotic syndrome due to collapsing glomerulopathy.

❖ We report a case of nephrotic syndrome caused by diabetic nephropathy, presenting with non-cardiogenic pulmonary edema.

Fig 1: This X-ray was performed on admission and showed diffuse bilateral patchy alveolar and interstitial opacities predominantly involving the upper lobes consistent with pulmonary edema.

Case Report

Case Presentation: A 37 year old man with a past medical history of diabetes mellitus type II, hypertension, and dyslipidemia, who presented with dyspnea, orthopnea, and non-productive cough for two days. He had been developing progressive abdominal distention and lower extremity (LE) swelling for three weeks prior to admission. He denies any chest pain, fevers, or chills.

Hospital Course: ❖ He appeared uncomfortable and hypoxic and had

abdominal distention with bilateral LE edema.

❖ Initial laboratory tests revealed BUN of 33, creatinine of 1.8, bicarbonate of 34, and albumin of 2.1.

❖ His random urine protein-to-creatinine ratio was 8.36 g.

❖ He had normal C3 and C4 levels.

❖ Chronic hepatitis panel, HIV, anti-GBM Ab, ANCA, ANA, anti-dsDNA, and RF were negative.

❖ EKG showed sinus rhythm, and echocardiogram revealed normal systolic and diastolic function with ejection fraction of 55-60%.

❖ Chest x-ray was consistent with volume overload and pulmonary edema.

❖ Kidney ultrasound was unremarkable.

❖ His kidney biopsy confirmed diabetic nephropathy as a cause of his nephrotic syndrome.

❖ He was diuresed with furosemide and metolazone and had a significant improvement of his volume status.

❖ He initially required oxygen to keep his oxygen saturation above 91% and was subsequently weaned to room air following diuresis.

Conclusion

We report this case to make clinicians aware that patients with nephrotic syndrome can present with non-cardiogenic pulmonary edema and hypoxia as their initial presentation. This complication is effectively managed with diuresis.

Fig 2: This X-ray was performed before discharge and showed significant improvement in his pulmonary edema.

References1. Bali HK, Jha V. Nephrotic syndrome and recurrent pulmonary oedema in bilateral atherosclerotic renal artery stenosis: Resolution following renal angioplasty and stenting. Natl Med J India. 2006;19(5):253-254.

2. Hull RP, Goldsmith DJ. Nephrotic syndrome in adults. BMJ. 2008;336(7654):1185-1189. doi: 10.1136/bmj.39576.709711.80 [doi].

3. Kodner C. Nephrotic syndrome in adults: Diagnosis and management. Am Fam Physician. 2009;80(10):1129-1134.

4. Orth SR, Ritz E. The nephrotic syndrome. N Engl J Med. 1998;338(17):1202-1211. doi: 10.1056/NEJM199804233381707 [doi].

5. Wiederkehr MR, Rogers TE, Moe OW. Collapsing glomerulopathy: A cause of noncardiogenic pulmonary edema. Am J Kidney Dis. 2002;40(3):E10. doi: S0272-6386(02)00100-2 [pii]. (*Contributed equally)

Fig 1 Fig 2

Fig 3: The glomeruli was examined with Hematoxylin and eosin stain, and periodic acid–Schiff stain. The glomeruli, demonstrate nodular mesangial expansion, which is PAS positive Kimmelstiel-Wilson nodules. There is moderate tubular atrophy and moderate interstitial fibrosis. Scattered PAS positive casts are identified. The tubular basement membranes are thickened. There is a moderate interstitial inflammatory infiltrate, which is composed predominantly of lymphocytes and plasma cells, admixed with rare eosinophils. In addition, there is hyaline arteriosclerosis.

Fig 3 Fig 3