Oxford Assess and Progress

Question 1

A 70-year-old man attends his local general hospital for a blood test having started taking lisinopril 10mg PO once daily 2 weeks previously. His doctor contacts him with the results (Table 5.1).

Table 5.1 Blood results pre- and post-lisinopril

Pre-lisinopril
Estimated glomerular filtration rate 50 (eGFR; mL/min)
Creatinine (μmol/L) 150

2 weeks later
Estimated glomerular filtration rate 40 (eGFR; mL/min)
Creatinine (μmol/L) 180

Which is the single most appropriate management?

Answer 1

Repeat the test in 10 days time.

NICE guidance is that if the fall in eGFR is <25% and the rise in serum creatinine is <30%, then the results can be rechecked within 2 weeks without altering the dose of the angiotensin-converting enzyme (ACE) inhibitor. If the fall is more precipitous, then other causes of acute renal failure (hypovolaemia, other drug side effects) need to be excluded. If no other cause can be found, then the ACE inhibitor should be stopped, with an alternative antihypertensive added if required.

Question 2

A 66-year-old man has had a right femoral popliteal bypass. He had 2.5L of IV fluids (a mixture of colloid and crystalloid) during the operation.
T 36.5°C, HR 72bpm, BP 105/65mmHg, RR 14/min.

There is a central venous line, a urinary catheter, and an epidural in situ. The nursing staff call the on-call junior doctor because the patient has not passed urine in the last 4h. Which is the single most appropriate course of action? ★

A Abdominal examination
B Change catheter
C Fluid challenge: colloid 500mL IV STAT
D Mixed venous saturation from the CVP line 
E Turn off the epidural

Answer 2

2. A ★
   Hopefully, this is an obvious measure to take, but if in a rush on call, a reflex response to oliguria may be a quick fluid challenge (C) before rush- ing to another ward. However, before it can be assumed that the patient is not producing urine because of dehydration, a blocked catheter must be excluded. If examination of the abdomen reveals dullness to percus- sion up to the umbilicus, then the catheter itself and its patency need to be checked.
   B Thiswouldbetheroutetogodownifabdominalexaminationrevealsa full bladder and the catheter seems patent but does not fill on flushing.
   D Mixed venous saturations more than 75% and a CVP >8–10cmH2O would suggest that the patient was well filled and are useful ways of assessing fluid status.
   E Epidural analgesia typically lowers blood pressure, but switching it off is not the answer in suspected dehydration.

Question 3

A 37-year-old man has had 12h of severe abdominal pain. It comes in waves and is associated with nausea. He has had this pain once before but it passed without him having to resort to medical help. His
kidneys, ureters, and bladder (KUB) film is shown in Figure 5.1.

Which single finding on the image is most supportive of the likely diagnosis? ★
A Calculus at the left vesico-ureteric junction
B Calculus at the right vesico-ureteric junction
C Dilated right pelvic calyces
D Distended bladder
E Rightdelayednephrogram

Answer 3

3. E ★
   Although all options fit with the history, only E is present on the film. It is an IV urogram taken 20min after the injection of contrast dye. Immediately following this infusion, the contrast should be promptly taken up by a normal kidney and would create a distinct outline (or ‘nephrogram’) on the initial 1min film. A well-demarcated kidney on a 20min film, as in this case—a ‘delayed nephrogram’—is a sensitive indicator of ureteral obstruction and renal function derangement. If the obstruction is acute, the delay is usually only for a few minutes, whilst in long-standing obstruc- tion, the uptake of contrast by the kidney can be 1h or longer,leading to a persistently dense nephrogram.