A 45-year-old male with a history of alcohol abuse has been intubated and ventilated following an out of hospital cardiac arrest. Forty-eight hours after admission the following results were obtained:
|
Parameter |
Patient Value |
Adult Normal Range |
|
Sodium |
134 mmol/L* |
135 – 145 |
|
Potassium |
3.3 mmol/L* |
3.5 – 5.0 |
|
Chloride |
107 mmol/L* |
95 – 105 |
|
Bicarbonate |
19.0 mmol/L* |
22.0 – 26.0 |
|
Glucose |
6.7 mmol/L* |
3.5 – 6.0 |
|
Urea |
5.9 mmol/L |
3.0 – 8.0 |
|
Creatinine |
59 μmol/L |
45 – 90 |
|
Magnesium |
0.79 mmol/L |
0.75 – 0.95 |
|
Albumin |
20 g/L* |
35 – 50 |
|
Protein |
54 g/L* |
60 – 80 |
|
Total bilirubin |
82 μmol/L* |
< 26 |
|
Aspartate aminotransferase (AST) |
249 U/L* |
< 35 |
|
Alanine aminotransferase (ALT) |
41 U/L* |
< 35 |
|
Alkaline phosphatase (ALP) |
124 U/L* |
30 – 110 |
|
-Glutamyl transferase (GGT) |
481 U/L* |
< 55 |
|
Calcium corrected |
2.26 mmol/L |
2.12 – 2.62 |
|
Phosphate |
0.49 mmol/L* |
0.80 – 1.50 |
|
Creatinine Kinase |
114 U/L |
46 – 171 |
|
Lipase |
19 U/L |
< 60 |
a) Give a rationale for the results observed. (50% marks)
Mild hyponatraemia and hypokalemia may be secondary to fluid therapy or diuretic treatment. Mild acidosis may be secondary to initial ischaemic insult, or hyperchloraemic in the setting of fluid resuscitation.
Low phosphate and protein may indicate pre-existing malnutrition: risk of refeeding.
Features of liver impairment or failure with elevated total bilirubin, GGT, AST and ALT.
High AST to ALT ratio is associated with cirrhosis. rhabdomyolysis (unlikely as CK normal).
In this context both ischaemic liver damage (from out of hospital cardiac arrest) and alcoholic liver damage should be considered. However, the normal renal function may make ischaemic liver damage less likely. The high AST may reflect AMI as a precipitating factor for the arrest.
"Rationale for the results observed" appears to be a request for an unordered list of abnormalities, judging by the college answer. Thus, they are presented here in the format of abnormality(rationale)
It is unclear how this tests anything.