SAQ 579 – Metabolic – mixed acid-base disturbance with hypokalaemia

A 55-year-old woman with congestive cardiac failure and diabetes is brought to the emergency department by ambulance with vomiting and drowsiness. There are no clinical signs of trauma. Her venous blood gas is shown below.

Observation	Result
Blood pressure	95/60 mmHg
Heart rate	110/min
Respiratory rate	28/min
SpO2	94% room air
Temperature	37 C
GCS	14 (E3 V5 M6)

Parameter	Result	Reference range
pH	7.41	7.32-7.42
PCO2	32 mmHg	41-51
HCO3	19 mmol/L
Sodium	144 mmol/L	135-145
Potassium	2.7 mmol/L	3-5
Chloride	90 mmol/L	95-107
Glucose	25 mmol/L	3.0-10.0
Lactate	1.8 mmol/L	0.5-2

State the likely explanation for these gas results in this patient.

(Marked out of 3.0)

/ 3

Calculate the anion gap, show your calculation, and state whether it is normal or abnormal.

(Marked out of 2.0)

/ 2

Calculate the approximate delta gap and show your calculation.

(Marked out of 2.0)

/ 2

What acid-base disturbance does the delta gap suggest?

(Marked out of 1.0)

/ 1

List four (4) ECG changes expected with hypokalaemia.

(Marked out of 4.0)

/ 4

Total Score: 0 / 12

Percentage: 0%