Question

Read the following case study and answer each of the questions. Daryl is an 18-year-old male, who was diagnosed with type 1 diabetes 10 years ago. He is brought to the emergency department by his parents. Daryl seems anxious and confused. He is pale and hyperventilating. He has a racing heart rate and hypotension. Blood glucose measurements indicate a serum glucose of 350 mg/dL. Daryl explains that he ate "some junk food" with friends and forgot to take his insulin. Arterial blood gases are as follows: pH=7.25 PaOz 100 mm Hg PaCO2 = 22 mm Hg Serum values reveal hyperkalernia, reduced bicarbonate, and acetone. 1. What acid-base abnormality does Daryl display? 2. Why is Daryl's PCO, value lower than normal? 3. Why is Daryl hyperventilating? 4. Why is Daryl's serum bicarbonate reduced? 5. Why is Daryl experiencing hyperkalemia? 6. What is the significance of the presence of acetone in the serum samplo? 7. What medical intervention may help Daryl's condition?

Answer 1

The CLINICAL PICTURE SUGGESTS OF DIABETIC KETO ACIDOSIS

1). Daryl exhibits METABOLIC ACIDOSIS . This condition is mainly due to diabetic ketoacidosis. Since he is a type 1 diabetic patient and forgot to take insulin , the glucose levels are elevated and the cells are unable to take the glucose due to absence of insulin and thus they use up fat storages which produces acetic acid, aceto acetic acid and beta hydro butyric acid as the end product . There is an increse in acetone level in the blood thus the keto acids disociates and binds to bicarbonate . Hence the ph decreases, paco2 decreases and bicarbonate also decreases causing metabolic acidosis.

2). Normal paco2 value is 38 to 42 mm hg

due to diabetic ketoacidosis , metabolic acidosis occurs which will induce hyperventilation, by stimulation of peripheral chemoreceptors , and respiratory centre in the brain stem ,, thus paCo2 level is decreased . Here pAco2 is reduced to 22mmHg . Thus the more carbon dioxide will be removed and it will increase the ph .

3). Daryl hyperventilate to compensate the metabolic acidosis which lowered the ph of the blood . Here the ketone bodies produced as end product dissociates and hydrogen ion combines with bicarbonate ,, decreasing blood ph , thus to remove this carbon dioxide and to increase the ph ,, daryl hyperventilates due to decreased paCo2 .

4) serum bicarbonate is reduced because increased ketone bodies are present which dissociates in the blood and the hydogen ion from the ketone bodies binds with bicarbonate leading to its reduction.  

5). The increased blood glucose and ketone level causes the potassium to efflux from the cell and buffering of excess hydrogen ions in cell leads to efflux of potassium ions causing hyperkalemia .

Another theory is insulin redistribute potassium inside the cell through sodim potasium pump . In decreased insulin level hyperkalemia occurs .

6). Presence of ketone in urine signifies diabetic ketoacidosis which needs immediate treatment orelse it leads to coma and death .

7). Diabetic ketoacidosis must be treated in icu for 24 to 48hrs .

• Correction of fluid loss with ringer lactate given iv
• Correction of hyperglycemia with insulin
• correction of electrolyte imbalance
• Correction of acid base balance
• Treatment for any other infection if presents