Hb 65, ESR 110. Differentials?

ESR-01
What ESR really measures

A 67 year old woman had an unexplained Hb of 65 g/L. The only previous Hb result was 103 g/L from over four years ago. She felt generally tired with achy muscles most of the day for the past few months. An ESR had been sent, and came back as 110.

Q. Arrgh! PMR! Myeloma! Anaemia of chronic (rheumatological disease) of some kind!

A. Possibly. But it’s still quite likely that the ESR is a result of the anaemia, which raises the Rate at which Erythrocyte Sedimentate (sedimentate is totally a word).

Q. Dammit. We can only use CRP in these situations reliably.

A. You could measure plasma viscosity directly instead of ESR. This is expensive and not done in the NHS generally, and anyway you don’t usually need to unless you are a rheumatologist. And if you are, you probably know more about the merits of CRP vs ESR vs PV than me so I’ll shut up.

Q. Is this your shortest post yet?

A. Yes.

Q. Why?

A. Because if you can’t get a reliable ESR result, it doesn’t matter. Most of the conditions which benefit from ESR over CRP can be reviewed by a rheumatologist later. The only emergency where an ESR changes management is GCA; if you suspect this in a patient with an unreliable ESR, you can discuss with an on-call rheumatologist or treat now and await the formal biopsy.

Aortic Regurgitation: My favourite valvulopathy

This may seem like a very sad title for a blog post. That’s because it is. My last 6 month rota in A&E (working 3 in 4 weekends, with stretches of 5 days followed immediately by 4 nights) was like having my circadian rhythm controlled by a Geiger counter. I found myself waking at random hours, worried about what happened to patients I had seen. Real life and sleep rolled into one. I was probably GCS 14/15 most of the time. In short, I became sad and could only really think medicine. I was routinely staying past my hours because I didn’t want to hand over complex cases to the overstretched night staff. It wasn’t a great time for certain health ministers to imply junior doctors lack vocation or are killing patients by not working more weekends. I think it was these suggestions by Jeremy Hunt more than the details of the new contract that turned junior doctors so overwhelmingly against him and by extension his contract.

Now that I’m on a medical firm, my enthusiasm for geeky medicine has returned. Here’s something I heard recently at the left lower sternal edge of an otherwise well 85 year old woman.

 

The patient had a blood pressure of 156/89 and a regular pulse of 74.

Q. Classic aortic regurgitation. Early diastolic left lower sternal edge, loudest in expiration and on leaning forward. Love it. That’s typical.

A. Actually, mixed aortic valve (i.e. stenosis and regurgitation) disease is probably at least as common than pure AR. The management of mixed aortic valve disease depends on which valve problem is the dominant pathology.

Q. How do you tell that then?

A. Stenosis decompensates into a pressure overload situation, with a narrow pulse pressure. Regurgitation causes a volume overload sitation, with a wide pulse pressure and a hyperdynamic circulation. Echo can help distinguish which is the dominant effect. What matters isn’t so much the gradients/surface areas (although that it relevant), but how much functional impact each valve problem is having on the heart itself.

Q. Water hammer pulses, eh?

A. Yes. I used to get really confused about all the quirky signs of aortic regurgitation as a medical student. They all boil down to a hyperdynamic, superficial-ish arterial-ish vessel leading to a pulsing of something. The water hammer pulse is quite simple:

-> low diastolic pressure in AR, so

-> raising arm means gravitational force pushing blood back down the arm to the body is greater than the rubbish diastolic pressure, so

-> blood drains rapidly during diastole, so you get a sharp high volume pulse in systole which then quickly disappears, so

-> the pulse is ‘tapping’ like a woodpecker in slow motion. Or, if you prefer, water hammer (see the waveform):

Classic video for a classic valvulopathy.

Q. What is the Austin Flint?

Austin Flint = AF = Aortic is Farting back to the mitral valve. Sorry if it’s crude, but it helps me visualise blood flowing back down the aortic valve with such passion and speed that it flows all the way back to the mitral, causing a mid-diastolic murmur as jets flow onto the anterior leaflets of the mitral valve.