Wed3November0903PM 10

A 62-year-old man presents to the Emergency department at 5 am with a third episode of pulmonary oedema in the past four months. On each occasion he is hypertensive with a BP of >175 systolic, and responds to IV nitrate therapy. Current therapy includes ramipril 10 mg daily and furosemide 40 mg daily.

On arrival in the Emergency department his BP is 185/100 mmHg, pulse is 95 and regular. There are crackles to the mid-zones bilaterally consistent with cardiac failure, and his O2 saturation on air is 91%. He responds to IV GTN.

Investigations reveal:

Hb 118 g/L (135-180)

WCC 9.9 ×109/L (4-10)

PLT 322 ×109/L (130-400)

Na 138 mmol/L (135-145)

K 5.2 mmol/L (3.5-5.5)

Urea 12.4 mmol/L (2.5-8)

Cr 185 µmol/L (50-90)

ECG shows LVH, no other acute changes.

CXR shows gross pulmonary oedema.

USS abdomen shows right kidney normal size (11 cm), left kidney 9 cm in length.

Which of the following is the most appropriate intervention?

(Please select 1 option)

Increase furosemide Incorrect answer selected

Cardiac angiography +/- angioplasty and stenting

Renal angiography +/- angioplasty and stenting This is the correct answer

Stop ramipril

Add bisoprolol

Explanation

Differential kidney size and flash pulmonary oedema raises the possibility of renal artery stenosis.

The following situations drive further investigation for potential renal artery stenosis:

Refractory hypertension (ie blood pressure >150/90 mm Hg despite three antihypertensive agents)

Recurrent episodes of pulmonary oedema despite normal left ventricular function on echocardiography (flash pulmonary oedema)

Rising serum creatinine concentration (rise of =20% or fall of glomerular filtration rate (GFR) >15%) over 12 months with a high clinical suspicion of widespread atherosclerosis, or during the first 2 months after initiation of treatment with an ACE inhibitor or angiotensin receptor blocker.

Reviews/guidelines suggest the strongest evidence for intervention with angioplasty +/- stenting in renal artery stenosis is in patients with unexplained pulmonary oedema.

In this case medical therapy is unlikely to prevent further episodes of pulmonary oedema, although angioplasty and stenting of the affected renal artery potentially will.

In this situation volume depletion associated with increasing furosemide may drive a significant worsening in creatinine. Bisoprolol may impact positively on cardiac function, but may also reduce this patient's ability to deal with increased peripheral resistance, thus actually worsening the risk of further episodes of pulmonary oedema. In the presence of likely normal cardiac function, coronary angiography is not of value.

Reference:

Lao D, Parasher PS, Cho KC, Yeghiazarians Y. Atherosclerotic renal artery stenosis--diagnosis and treatment. Mayo Clin Proc. 2011;86(7):649-57.

Answer Statistics

1

13%

2

7%

3

42%

4

27%

5

13%

Times answered: 281