Lab Case 9 – Interpretation

Critically unwell patient with

1. shock – hypotensive, tachycardic, hypothermia

2. life threatening acidaemia and lactic acidosis

He requires immediate fluid resuscitation and investigation for causes. Will need HDU/ICU admission

pH 6.91 severe acidaemia

HCO3 7.2, BE -24.5 severe metabolic acidosis

Anion gap 31 severe high anion gap metabolic acidosis (HAGMA)

Causes – sepsis, renal failure, ketones, toxins

Compensation using Winter’s formula: expected CO2 18, actual is 36

therefore uncompensated and likely additional respiratory acidosis due to prolonged hypoventilation (loss of consciousness, seizure, other)

Delta ratio 19/17 = 1, pure HAGMA

Unable to comment on Aa gradient on venous gas

High lactate (life threatening) – severe shock, sepsis, seizure, toxins

Normal glucose – urine showed 2+ ketones – alcoholic ketoacidosis, starvation ketoacidosis

Urea 8, Creat 120 – mild renal failure, dehydration, fluid depletion

high WCC/N – sepsis (backpain – ?diskitis)

Hb 171 – polycythaemia, dehydration

Osmolality 308 – high – dehydration

mild elevation in Na – dehydration

Normal K – however due to severe acidosis the total body K is likely to be depleted. Monitor K and replace as required

Normal Cl


60 year old male with severe life threatening HAGMA and respiratory acidosis

Causes in this patient are multifactorial and may include:

1. seizure – hypoglycaemia, alcohol withdrawal, epilepsy

2. dehydration, shock

3. alcoholic/ starvation ketoacidosis

4. sepsis -?discitis, other (CXR was normal and UA only ketones)

5. Bleeding – GI (oesophageal varices, PUD) – PR was normal

6. Abdominal – pancreatitis (lipase was normal), gastritis, liver failure (LFT actually better than previous results, INR 1.3), abdominal catastrophy

7. Toxins – esp toxic alcohols (require osmolar gap). This patient did not present clinically as a toxic alcohol ingestion. His family were confident that this was not possible.

His blood alcohol level was 0

8. Respiratory acidosis – see earlier

So, what did we do?

1. managed in resuscitation bay

2. full non invasive monitoring

3. 2 large ivi cannulas

4. fluid resuscitation – initial fluid 0.9% saline

5. antiemetics

6. analgesia – paracetamol, pantoprazole

7. antibiotics – Tazocin 4.5grams

What about the severe acidosis?

We used isotonic HCO3 – 150mls of 8.4% HCO3 in 850mls of water/5% dextrose. Initially 250mls per hour over two hours, then 100mls/hr. When he finally went to ICU his pH was 7.27, HCO3 16, lactate 14, BP 120/60, PR 110/min. GCS was 15. Passed 100mls urine. Abdominal pain completely settled.