Urine ketoacidosis tests

Urine testing can play a role in identifying ketone excretion in patients prone to ketoacidosis. If urine testing is done, it is usually recommended tiiat the nurse use the second voided specimen (ie, fresh urine collected 30 minutes after the initial voiding) to check glucose or acetone levels, ratiier than die first specimen obtained. 

Diabetic acidosis can develop in a matter of hours. Therefore, under certain circumstances, doctors may ask a diabetic patient to test for ketones at home using special test strips that can detect ketones in urine. For example, doctors recommend that diabetic patients test their urine every 4 to 6 hours if their blood sugar levels are very high. Patients should also test for ketones if they are sick with a cold or the flu, or if they experience any of the symptoms of acidosis. These symptoms include a very dry mouth, frequent urination, shortness of breath, and fruity smelling breath. Diabetic acidosis can be life-threatening, leading to a diabetic coma or death. It needs immediate medical care. Diabetic acidosis is also called ketoacidosis. 

By far the most likely diagnosis in this case is diabetic ketoacidosis. This may be precipitated by a number of conditions, such as infection. This may have caused anorexia and, thus, the patient may have omitted to take her insulin. Trauma can increase a patient s requirement for insulin but there is nothing to suggest that in this case. The blood glucose can be checked at the bedside as can a specimen of urine for the presence or absence of ketones. The laboratory tests which may be requested are urea and electrolytes to assess renal function, the presence or absence of hyperkalaemia and the serum sodium concentration. The patient s acid-base status should be assessed to quantitate the severity of the acidosis present, and the blood glucose should be accurately measured. These will influence the patient s treatment. It is essential in cases such as this that samples of blood and urine and, if appropriate, sputum are sent to the microbiological laboratory to look for the presence of infection. 

This is a measure of the renal excretion of hydrogen ions. It can be determined by measuring the amount of alkali required to titrate a fixed volume of the urine to pH 7.4. Titratable acidity is increased when acid-forming foods have been taken and in some acidotic conditions, such as diabetic ketoacidosis when keto acids are excreted in the urine. Titratable acidity can also be measured in the ammonium chloride loading test (q.v.), a procedure designed to test the ability of the kidneys to excrete an acid load. 

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