Health Awareness blog

Hyperkalemia is an emergency and needs urgent treatment. Hyperkalaemia is diagnose when a plasma potassium >6.5mmol/L.

Signs and symptoms:

·         ECG = Tall tented T waves, small p wave, wide QRS complex becoming sinusoidal, VF

·         Cardiac arrhythmias

·         Sudden death

Causes:

Spurious:

·         Leakage of potassium from erythrocytes when separation of serum from clot is delayed (artifact, the plasma potassium is normal)

·         Release of potassium from marked thrombocythaemia (platelets count high) or leucocytosis (high white cell count)

·         Repeated fist clenching during blood taking (release of potassium from muscle)

·         Specimen taken from arm with potassium infusion

Decreased excretion:

·         Acute or chronic renal failure

·         Renal secretory defects – this may be found in renal transplant, interstitial nephritis, systemic lupus erythematosus (SLE), sickle cell disease, amyloidosis, obstructive uropathy,

·         Addison’s disease (due to loss of function of hormone aldosterone which is responsible for potassium excretion in kidney)

·         Hyporeninemic  hypoaldosteronism – A rare condition where low levels of rennin result in insufficient aldosterone being produce (often seen in diabetic patients with mild to moderate nephropathy) or selective hypoaldosteronism (some patients with AIDS)

·         Heparin (this will suppress aldosterone secretion)

·         Drugs that inhibit potassium excretion (e.g.: spirinolactone, eplerenone, triamterene, ACE inhibitors, angiotensin II receptor blockers, trimethoprim, NSAIDs, cyclosporine, tacrolimus)

Shift of potassium from within the cell

·         Massive release of intracellular potassium – seen in burns, rhabdomyolisis, hemolysis, severe infection, internal bleeding, vigorous exercise

·         Metabolic acidosis (e.g.: diabetes mellitus)

·         Hypertonicity (solvent drug)

·         Insulin deficiency 

·         Hyperkalemic periodic paralysis

·         Drugs: succinylcholine, arginine, digitalis toxicity, beta adrenergic antagonists

·         Alpha adrenergic stimulation

·         Massive blood transfusion

Excessive intake of potassium:

·         Excessive intake of food rich of potassium (e.g.: banana)

·         Excess potassium therapy

Hyperkalemia can be prevented by controlling the disease and frequent monitoring of electrolytes if the patients take the few medications that have been listed above.

Treatment:

Treat underlying cause is the means of treatment. In emergency cases, the management should be:

·         10ml intravenous calcium gluconate (10%) over 2 min, repeated as necessary if ECG changes is severe. This is only to provide cardio-protection. Serum potassium will remain high without other treatment. Caution should be taken with calcium guconate because it may cause skin necrosis if extravasation. This drug should not be injected into small peripheral cannulae.

·         Intravenous insulin (e.g.: 10unit insulin) will moves the potassium into the cells. It usually given with intravenous glucose (e.g.:50ml of 50% glucose solution)

·         Nebulized salbutamol (2.5mg) will also have the same effect with insulin

·          Polystyrene sulfonate resin either orally or enema if patient has problem to take orally. This should colonic irrigation after about 9 hours to remove the potassium from the colon.

·         Dialysis will be done if none of these things works

Reference:

1.       Oxford handbook of Clinical Medicine. 7^th edition. Oxford University Press. 2008.

2.       http://en.wikipedia.org/wiki/Addison_disease

3.       Current Medical Diagnosis and Treatment. Mc Graw Hill. 2008.

4.       http://www.wrongdiagnosis.com/h/hyporeninemic_hypoaldosteronism/

Bulimia nervosa is a type of eating disorder characterized by self induced vomiting. This type of eating disorder commonly associated with anorexia. The affected persons often use emetine or other medications to help induce vomiting. Females are more common than males with the ratio of 20:1 and high prevalence in young women and college women. Study has done and noted 1/3 of the sufferers have background history of sexual abuse during childhood.

Diagnostic criteria:

• Recurrent episode of binge eating
• Recurrent inappropriate compensatory behavior to prevent weight gain
• Binge eating and inappropriate compensatory behaviors occurring, on average, at least twice weekly for 3 months
• Self evaluation in duly influenced by body shape and weight
• The disturbance does not occur exclusively during episodes of anorexia nervosa

Binge eating is characterized by:

• Eating in a short period of time (e.g.: 2 hours) an amount of food larger than most individuals would eat during a similar period of time and under similar circumstances
• A sense of lack of control over eating(e.g.: amount and type of food)

Pathophysiology:

Diminished cholecystokinin production causes decreased satiety and CNS (central nervous system) serotonin.

Sign and symptoms:

· Onset usually a bit later than anorexia

· Compulsive eating binges usually followed by anxiety and guilt, which then lead to purging

· Callus on back of hand usually can be seen. It developed after frequent emesis induction.

· Dental caries (from gastric fluids on teeth)

· Enlarged salivary glands

· The affected person usually appears thin and normal weight

· Postural blood pressure drops

Investigations:

• FBC – to look for evidence of anemia
• BUSE – to look for electrolyte imbalance à hypokalemia (low potassium), high HCO3 (high bicarbonate). In laxative use, the result usually normal anion gap acidosis.
• Serum amylase – usually elevated, sometimes due to pancreatitis but most of the times due to salivary origin (lipase and pancreatic fraction is normal)
• Urine emetine levels
• Urine qualitative ipecac
• ECG or EKG at some regular interval

Complications:

• Cardiac heart failure (from starvation)
• Ipecac myocardiopathy and myopathy
• Aspiration pneumonia (lung infection)
• Mallory-Weiss tears
• Hypokalemia (low potassium levels)
• Sudden death (due to long QT syndrome)

Treatment:

· Rehydration

· Correct the electrolytes imbalance

· Give calcium and vitamin D supplement to prevent osteoporosis

· Fluoxetine (Prozac) 20mg – 60mg orally 4 times/day

· Psychotherapy (i.e.; cognitive behavioural therapy)

Reference:
1.Quick Reference Cards by Medical Protection Society. 2001.
2.The Little Black Book of primary Care. Daniel K. Onion. 5^th edition.