Lab case 41 – Interpretation

A 27 year old female, unwell requiring simultaneous assessment and management of her immediate life threats.


1. Describe the abnormalities

Normal pH

low HCO3 and BE

CO2 28.4 (expected 32 +/- 2), in setting of likely VBG

Anion Gap = 11 (normal)

===> Compensated normal anion gap metabolic acidosis

hyponatraemia (corrected = 130)


severe hypocalcaemia

high glucose (no ketones given, normal anion gap)

Low pO2 – venous sample

2. Interpret your findings

(a) Biochemical features consistent with multiple endocrine dysfunction:

Addison’s disease (low Na, high K, NAGMA)

Uncontrolled Diabetes (check ketones)


Check Thyroid function ( very fast HR)

(b) Features of Sepsis:

hypotension, tachycardia, fever and features on history suggestive, lactate is normal

3. Examination Features:

(a) Source of infection – thorough head to toe examination, including ENT, chest, abdomen. CXR and UA immediately

(b) Severity of sepsis/ complications – GCS, perfusion, UO, Ileus,

(c) Features of Addison’s – weight loss, hyperpigmentation

In general, some features of Addison’s include:

  • Muscle weakness and fatigue
  • Weight loss and decreased appetite
  • Darkening of your skin (hyperpigmentation)
  • Low blood pressure, even fainting
  • Salt craving
  • Low blood sugar (hypoglycemia)
  • Nausea, diarrhea or vomiting
  • Muscle or joint pains
  • Irritability
  • Depression
  • Body hair loss or sexual dysfunction in women

(d) Features of hypocalcaemia

“CATS go numb”- Convulsions, Arrhythmias, Tetany and numbness/parasthesias in hands, feet, around mouth and lips.

  • Petechiae, purpura
  • Oral, perioral and acral paraesthesia (early symptom)
  • Carpopedal and generalized tetany
  • Latent tetany
    • Trousseau’s sign
    • Chvostek’s sign
  • Tendon reflexes are hyperactive
  • Life-threatening complications
    • Laryngospasm, brochospasm
    • Cardiac arrhythmias
  • Effects on cardiac output
    • Positive chronotropy
    • Negative inotropy effect
  • ECG – Intermittent QT prolongation – high risk of TdP

Chronic hypocalcaemia – poor dentition, cataracts, papilloedema, ectopic calcification, dementia

(e) Complications of Diabetes:



Renal impairment….. etc

4. Treatment Priorities

Full cardiac monitoring, serial ECG’s, defib pads applied

Resuscitation – as per surviving sepsis – fluids, antibiotics (source control), other – inotropes, monitor response to treatment

Replace Calcium – 10 mls of 10% Ca Gluconate iv

Steroids – hydrocortisone 200 mg ivi/ Dexamethasone

Insulin Infusion  (2-4 units/hr)- aim to correct ketoacidosis if present and correct glucose gradually over 2-4 hours