Diabetic Coma And Ketoacidosis: Clinical Significance Of Its Management And Insulin Therapy
Correcting Dehydration In Diabetic Coma
The following are the principles of management of diabetic ketoacidosis
- Correction of dehydration
- Correction of electrolyte disturbances and acidosis
- Control of hyperglycemia
- Removal of precipitating factors like infection
- Supportive measures
- Long- term management
Diabetic ketoacidosis is a medical emergency requiring hospitalization for treatment. In comatose patients, nasograstric tube is introduced to aspirate the stomach contents. No oral feeds are permitted. These measures help to avoid aspiration pneumonia.
Correction of dehydration: Fluid and electrolytes should be replenished as early as possible and this is the most effective single step to arrest further deterioration and bring about recovery. Normal saline is the fluid of choice to start treatment. The approximate fluid deficit ranges from 2- 8 liters depending on the severity of the condition. The speed of administration of isotonic saline for a moderately severe case is given below.
Amount In Liters
Time In Hours
4 (Total infusion of 6 liters in 11 to 12 hours)
Blood glucose and plasma bicarbonate are estimated at 2- hourly intervals. When the blood glucose falls below 250 mg/dl, 5% glucose solution may be given instead of saline. This helps in preventing hypoglycemia and also providing water for correcting cellular dehydration. By this time, most of the patients regain consciousness and are able to take oral feeds. At this stage, oral intake is increased and intravenous administration is tapered off.
Diabetic coma is the most urgent indication for soluble insulin. Insulin has to be given intravenously in moderate or severe cases. In mild cases indulin may be given intramuscularly.
Dose: Since large intermittent doses may lead to complications such as late hypoglycemia, hypokalemia, hyperlactatemia and osmotic disequilibrium, the present treand is to use smaller doses, 2- 10 units per hour continuously as slow intravenous infusion. In some cases, higher bolus doses may be required. Action of insulin lasts only for a few minutes if given intravenously. In mild cases, the same dose can be given intramuscularly every 1 hour.
Insulin is diluted with saline to give 0.1 unit/ml and administered in the drip or by intermittent injections in a dose of 6 units/hour (0.1unit/Kg/h for children) till the blood glucose comes down to 180 mg/dl. Thereafter, the dose of insulin is reduced to 3 units/hour. It is ideal to reduce the blood glucose by 90 mg/dl/h (5 mmol/liter/hr). In insulin- resistant cases (as determined by blood sugar estimations at 1 hour and 2 hour intervals) larger dose should be started without delay. It should be the aim to correct the metabolic abnormality within the shortest period, since prolongation of the coma may give rise to irreversible cellular damage. Insulin infusion is continued till the patient is able to take oral feeds and is fit for subcutaneous insulin.
If intramuscular injections of insulin are used, the dose is 20 units as loading dose and 6 units every 1 hour to be reduced to 6 units every 2 hours; when the blood glucose falls below 180 mg/dl. Once the emergency tides over, the patient should be put back on his regular insulin regiment.
Gaining Electrolytes Through Drinks
In addition to severe loss of sodium, there is also gross potassium deficit. The serum potassium level does not reflect the total body content since there is leakage of intracellular potassium to the extracellular compartment. In the early phases, the serum potassium level is high. With the normalization of metabolism with insulin and fluid replacement, potassium re-enters the cells. At this stage, serious hypokalemia may supervene. Administations of potassium early in the rgimen prevents this complication. If serum potassium is above 4 to 5 mEq/liter, potassium chloride administration is not started till the potassium falls with therapy. The dose and frequency are adjusted by 2- hourly serum potassium estimations. It is desirable to maintain the serum potassium level between 4 and 5 meq/liter. Potassium replacement is crucial to prevent death due to hypokalemia during recovery. In a severe case, approximately 100- 200 mEq of potassium may be necessary in the first 24 hours. Electrocardiogram monitoring is a helpful bedside method to indicate the effects of hypo and hyperkalemia on the heart.
Bicarbonate: Sodium bicarbonate is administered when there is severe acidosis indicated by the pH of blood below 7.1 and plasma bicarbonate level below 15 mEq/liter. Sodium bicarbonate is given slowly in dose of 55 to 100 meq/h (200 to 300 ml of 2.74% NAHCO3 solution). As the condition improves, the dose is reduced.
Foci of infection which may act as the precipitating factors should be identified. Appropriate antibiotic therapy should be started from the beginning. Other supportive measures include proper care of the mouth, attention to the bladder and bowels, maintenance of fluid balance charts, and prevention of decubitus ulcers. When the patient improves, he is rehabilitated and this usual antidiabetic regimen is restored. With modern lines of therapy, almost all cases of diabetic coma can be saved if the condition has not advance too far.
© 2014 Funom Theophilus Makama