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Greg Barton, specialist pharmacist critical care and burns, explains what pharmacists should look out for in patients with type 2 diabetes and co-existing cardiac disease

It is not uncommon for stable community-based patients to rapidly become unwell and require admission to a critical care unit or intensive care. Small changes in disease state, medication (changes in dose or new additions) or the onset of a new condition can all lead to a patient becoming acutely unwell.

A relatively common example that can be picked up and potentially prevented by a pharmacist is the type 2 diabetic with co-existing cardiac disease. These patients will generally be on metformin, a statin, an ACE inhibitor, diuretics such as furosemide and/or spironolactone and potentially a beta-blocker or angiotensin 2 antagonist.

A seemingly small or insignificant illness (e.g. a two-day history of diarrhoea or vomiting) can have a profound effect. Such patients will often present to the GP or hospital confused or drowsy as a result of dehydration and acute renal failure and can progress rapidly to multi-organ failure. They may also show up at a pharmacy requesting OTC antidiarrhoeals or electrolyte replacement sachets earlier in their illness. 

A seemingly small illness can have a profound effect

On presentation to hospital it will be rapidly apparent that the patient needs critical care management. Initial blood tests often show a high serum creatinine, a breakdown product of creatine phosphate in muscle, which is excreted unchanged by the kidney and so used as a marker of renal function. This figure can be 10-20 times that of the patient's normal baseline value and would immediately trigger a referral to critical care to manage with fluids and potentially renal replacement therapy such as dialysis.

Other initial abnormal blood tests often include:

• Raised potassium €“ this may be due the renal injury but it may also be compounded by the use of ACE inhibitors, angiotensin 2 blockers or an aldosterone antagonist (e.g. spironolactone), which all have a potassium-retaining effect
• Raised creatine kinase (CK) - this is used to screen for rhabdomyolysis, where myoglobin (a large oxygen-storing protein in the muscles) is released, clogging up the kidneys and leading to potential kidney failure
• Lactic acidosis €“ this is generally attributed to the failing kidney not clearing metformin and lactate from the body. Lactic acidosis can rapidly occur €“ small deviations in blood pH, for example a drop from normal (7.4) to 7.0, can be fatal.

All of the above can often quickly combine to mean a person who was fit and well only a couple of days previously has now become a critically ill patient requiring dialysis.

If caught early enough patients often go on to make a full recovery. Monitoring and vigilance by pharmacists can help prevent the initial incidence and ensure it doesn't happen again.