Lab case 235

A 10 year-old boy with a history of enuresis was BIBA to the ED after a first episode generalized tonic-clonic convulsion. He seemed tired in the morning but still attended his inter-school sports competition. While getting ready to compete he collapsed and had a self-limiting seizure (5 minutes duration).

He was afebrile and had GCS 13 (E3 V4 M6) (fluctuating) for about 4 hours without improvement. Pupils were equal and reactive and he had no focal neurological deficits. He vomited 5 times during this time but was clinically euvolemic. His CT head was normal.

He had the following laboratory test results:

PH                        7.37

PCO2                   42

HCO3                  24

Cl                         96

Na                       124

K                         4.1

Glucose               7.1

Lactate                2.7

 

Questions ; 

  1. what are the main lab abnormalities and how do they relate to above clinical presentation ?

Patient gets initial treatment in ED and gets admitted to ward. His other investigations come back as below:

Serum cortisol 1100 NM    (60-420)
TFTs were normal
Osmolality plasma 265 mmol/kg L    (275-295)
Spot urine sodium 209 mM
Spot urine osmolality 681 mmol/kg    (50-1200)

2.  what do these test results suggest?

3 . What is the underlying cause in this case?