A 68 year old man had both legs trapped under a heavy concrete slab for 4 hours. He has just been admitted to the ICU, 8 hours post injury, following adequate resuscitation and definitive operative wound debridement. His observations are that he is, fully conscious, his blood pressure is 110/70 mmHg, pulse 86 beats/min  and respiratory rate 24 breaths/min. He is anuric, and has been for the past 3 hours.

Relevant blood results at that time are:

 

Venous biochemistry

Test

Value

Normal Range

Sodium

138 mmol/L

135 -145

Potassium*

7.1 mmol/L

3.5 - 4.5

Chloride

100 mmol/L

95 -105

Bicarbonate*

11 mmol/L

22 - 26

Urea*

29 mmol/L

2.9 - 8.2

Creatinine*

310   mol/L

70 -120

Calcium*

1.71 mmol/L

2.10 – 2.55

Phosphate*

4.31 mmol/L

0.65 – 1.45

Creatine Kinase*

> 80,000 U/L

0 - 270

 

In reference to the above results, what process would the creatine kinase be reflective of and how would this affect the kidney?

 

Areas of weakness identified by examiners:

Few candidates seemed to have a structured approach and some were not familiar with dexmedetomidine and the recent trial data. No broad overview of sedation and analgesia agents with reference to the above patient considering the simplicity of the question. Many not familiar with dexmedetomidine pharmacology regardless of practical experience with the drug

Disclaimer: the viva stem above is the original CICM stem, acquired from their publicly available past papers. However, because the college do not make the rest of the viva text or marking criteria available, the rest has been confabulated. It sounds like a plausible viva and it can be used for the purpose of practice, but all should be aware that it does not represent the "true" canonical CICM viva station.