Basic investigations can be considered under the major headings of Bedside, Laboratory and Radiology. Use the 5 C’s approach to recognise, understand and manage metabolic disturbances.

• Cause – defining the potential causative events that lead to disruption
• Clinical manifestation – evaluate, recognise and diagnose the problem
• Complications – what can go wrong in the short, medium and long term
• Calculations – Calculate to Obviate
• Corrective measures – Call to action…how do you actually fix the problem!

Bedside

Urinalysis

• Urine Color
• Urine Transparency (turbidity)
• Dipstick urinalysis
• Urinalysis Overview Table
• Urine electrolytes – Urinary anion gap

Laboratory

Electrolytes

• Calcium: Overview – HYPERcalcaemia – HYPOcalcaemia
• Magnesium: HYPERmagnesaemia – HYPOmagnesaemia
• Potassium: HYPERkalaemia – HYPOkalaemia
• Sodium: HYPERnatraemia – HYPOnatraemia – SIADH – DI
• Chloride: HYPERchloraemia – HYPOchloraemia
• Phosphate: HYPERphophataemia – HYPOphophataemia

Acid-Base

• Acid-Base: ABG analysis – Anion Gap – SID – NAGMA
• Metabolic acidosis: Overview – evaluation – DDx
• Metabolic alkalosis: Overview – evaluation – DDx
• Respiratory acidosis: Overview – DDx
• Respiratory alkalosis: Overview – DDx

Renal Function

• Urea (Blood urea nitrogen – BUN)
• Creatinine
• Urea-Creatinine ratio
• Urate (Uric Acid)

Liver Function

• Liver Function Tests (LFT)
• Ammonia and hyperammonaemia
• Bilirubin and Jaundice

Other blood tests

• Autoimmune Markers
• Bleeding time
• Blood film
• CK-MB
• Coagulation profile
• D-dimer
• ESR – CRP
• Full blood count – Anaemia
• Osmolar gap
• Platelet function assays
• Thromboelastogram
• Thrombophilia screen
• VBG vs ABG

Other Tests

• Ascitic fluid analysis
• Bone marrow biopsy
• BHCG, Rhesus D and Progesterone
• Cerebrospinal Fluid (CSF)
• Thyroid Function Tests (TFT)
• Paracentesis (Ascitic Tap) fluid analysis
• Pleural Fluid Analysis
• Synovial fluid analysis

Radiology

• Abdominal X-Ray interpretation
• AXR and abdominal CT
• Chest X-Ray interpretation – Normal CXR
• CT Chest
• CT Head interpretation – MRI Head