Urology 4

oelomar's version from 2016-02-27 14:41


Question Answer
Low serum concentrations of Na+ results in…Disorientation, stupor, coma.
Low serum concentrations of K+ results in…U waves on ECG, fattened T waves, ST-segment depression, arrhythmias, paralysis, muscle weakness.
Low serum concentrations of Ca2+ results in…Tetany, neuromuscular irritability.
Low serum concentrations of Mg2+ results in…Neuromuscular irritability, arrhythmias.
Low serum concentrations of PO43- results in…Low-mineral ion production causes bone loss, osteomalacia.
High serum concentrations of Na+ results in…Neurologic: delirium, coma.
High serum concentrations of K+ results in…Peaked T waves, wide QRS complex, flattened P waves, arrhythmias.
High serum concentrations of Ca2+ results in…Delirium, renal stones, abdominal pain.
High serum concentrations of Mg2+ results in…Delirium, cardiopulmonary arrest.
High serum concentrations of PO43- results in…High mineral ion production causes renal stones, metastatic calcification.


Question Answer
What are the most common causes of chronic hypokalaemia?Diuretic treatment (particularly thiazides), and hyperaldosteronism.
Name at least 4 things that can cause for potassium to shift out of cells (causing hyperkalaemia).Insulin deficiency, β-antagonists, acidosis, hyper-osmolarity, cell lysis.
Name at least 4 things that can cause for potassium to shift into cells (causing hypokalaemia).Insulin, β-agonists, alkalosis, hypo-osmolarity.
What are the normal serum levels of potassium?3.5-5 mEq/L (mmol/L).
What is the association between hypokalaemia and digoxin toxicity?Hypokalaemia increases the risk of digoxin toxicity.
What is the association between hypokalaemia and ectopic beats?Hypokalaemia is associated with an increased frequency of atrial and ventricular ectopic beats.
What do patients with hypokalaemia present with?Fatigue, muscle weakness or cramps, ascending paralysis, hyporeflexia, (may also be asymptomatic).
How is mild hypokalaemia treated?Oral potassium.
How is severe hypokalaemia treated?IV potassium.
If hypokalaemia is not corrected following treatment by oral/IV potassium, what does one suspect?Concurrent hypomagnesaemia.


Question Answer
What serum potassium levels indicate hyperkalaemia?Mild: 5.1-6.0mEq/L. Moderate: 6.1-7.0mEq/L. Severe: 7.0mEq/L and above. Severe hyperkalaemia is treated as a medical emergency.
What do patients with hyperkalaemia present with?May be asymptomatic. Muscle weakness is often the only symptom. Symptoms include decreased cardiac excitability, hypotension, bradycardia, and eventual asystole.
How is hyperkalaemia treated?10 units of Actrapid insulin + 50ml of 50% IV glucose, 5mg nebulised salbutamol, bicarbonate (only if the patient is acidotic), haemodialysis or haemofiltration, IV Ca2+ (10ml of 10% Calcium gluconate given over 10 minutes). The first four mentioned treatments are meant for reducing plasma K+ whereas the IV calcium gluconate only counters the cardiotoxic effects of K+ rather than reduces the plasma concentration.
What are the normal levels of serum Na+?135-145 mEq/L (mmol/L).
What are the signs and symptoms of hyponatraemia?Nausea, vomiting, headache, short-term memory loss, confusion, lethargy, fatigue, seizures, decreased consciousness, or coma. Neurological symptoms typically occur with very low levels of plasma sodium (<115 mEq/L). When sodium levels in the blood become very low, water enters the brain cells and causes them to swell. This results in increased pressure in the skull and causes hyponatraemic encephalopathy.
What are causes of hypovolaemic hyponatraemia?This is due to salt loss in excess of water loss. Prolonged vomiting, severe diarrhoea, diuretic use, Addison’s disease.
What are the causes of euvolaemic hyponatraemia?This results from an intake of water in excess of the kidney’s ability to excrete it (dilutional hyponatraemia) with no change in body sodium content but the plasma osmolality is low. The most common cause is overgenerous infusion of 5% glucose into postoperative patients. Other causes include SIADH and hypothyroidism.
What are the causes of hypervolaemic hyponatraemia?Both sodium & water content increase: Increase in sodium content leads to hypervolemia and water content to hyponatremia. Total body water and sodium are regulated independently. Causes include CHF, cirrhosis, and nephrotic syndrome.
How is hypervolaemia treated?Water restriction.
How is hypovolaemia treated?Replete volume with normal saline.


Question Answer
What are the causes of hypernatraemia?This nearly always indicates a water deficit. Hypernatraemia is always associated with increased plasma osmolality, which is a potent stimulus to thirst. Hypernatraemia causes include the 6 D’s, which are: Diuretics (including osmotic diuresis as seen in hyperglycaemic and hyperosmolar states), Dehydration, Diabetes insipidus, Doctors (iatrogenic), Diarrhoea, Disease (e.g. kidney, sickle cell). None of the above cause hypernatraemia unless thirst sensation is abnormal.
How is hypernatraemia treated?The cornerstone of treatment is administration of free water to correct the relative water deficit. In severe hypernatraemia, 0.9% saline can be used. Correction of chronic hypernatremia (> 36–48 hours) should occur gradually over 48–72 hours to prevent neurologic damage secondary to cerebral swelling.
What are the normal levels of serum Mg2+?1.5-2.5 mg/dl (other sources say 1.7-2.2).
What are the causes of hypomagnesaemia?Decreased magnesium intake, including malabsorption, malnutrition, and total parenteral nutrition; and loss of magnesium, including diuretics, diarrhoea, vomiting, hypercalcaemia, alcoholism, and drugs (amphotericin). Other miscellaneous causes include DKA and pancreatitis.
What are the clinical features of hypomagnesaemia?Irritability, ataxia, tremor, hyperreflexia, and confusional and hallucinatory states.
What might an ECG show in a patient with hypomagnesaemia?Prolonged QT interval, broad flattened T waves, and occasional shortening of the ST segment.
How is hypomagnesaemia treated?Withdrawal of precipitating agents such as diuretics or purgatives. If symptomatic (or with hypocalcaemia), give parenteral infusion of magnesium.
What are the causes of hypermagnesaemia? It usually develops only in people with kidney failure who are given magnesium salts or who take drugs that contain magnesium (e.g. some antacids and laxatives). It can also be induced by magnesium-containing enemas. Mild hypermagnesaemia may occur in patients with adrenal insufficiency.
What are the clinical features of hypermagnesaemia?Symptoms and signs relate to neurological and cardiovascular depression, and include weakness with hyporeflexia proceeding to narcosis, respiratory paralysis and cardiac conduction defects.
How is hypermagnesaemia treated?Withdrawal of any magnesium therapy, calcium gluconate, insulin dextrose, and dialysis (in patients with severe renal failure).


Question Answer
What are normal blood urea nitrogen levels?7-20mg/dl (2.5-7.1mmol/L).
What is allopurinol and what is it used to treat?It is a xanthine oxidase inhibitor and it is used primarily to treat excess uric acid in the blood and its complications, including chronic gout. It can also be used in the treatment of IBD.
What is an ileal conduit?This is a surgical technique used in patients whom have had their urinary bladders removed. The surgeon creates an opening in the abdomen (stoma). The surgeon then takes a small segment of small intestine (that has been removed from the rest of the intestine) and connects one end to the stoma. The other end is connected to the ureters. The result diversion of urine into a bag that attaches on the outside of the body over the stoma.
What is the Mitrofanoff procedure?This is a surgical procedure in which the appendix is used to create a conduit between the skin surface and the urinary bladder. In the procedure, the surgeon separates the appendix from its attachment to the caecum, while maintaining its blood supply, then creates an opening at its blind end and washes it. One end is connected by surgical sutures to the urinary bladder, and the other is connected to the skin to form a stoma. Generally, an incision is made into the navel so it may serve as the canal for the catheter.