From the Guidelines

In Diabetic Ketoacidosis (DKA), administering fluids first is crucial.

The primary goal in DKA management is to restore circulatory volume and tissue perfusion, which can be achieved through aggressive fluid replacement 1.
Fluid administration helps to correct dehydration, reduce glucose levels, and improve insulin sensitivity.
0.9% NaCl or other crystalloid should be administered at a clinically appropriate rate, aiming to replace 50% of the estimated fluid deficit in the first 8-12 hours 1.
Insulin therapy can be initiated after fluid replacement has been started, with a typical dose of 0.05 units/kg/h i.v. insulin 1.
It is essential to monitor electrolytes, renal function, venous pH, osmolality, and glucose every 2-4 hours until stable 1.
Some studies suggest that insulin can be withheld until glucose has stopped dropping with fluid administration alone, but this approach requires careful clinical judgment 1.
The use of bicarbonate is generally not recommended, as it has not been shown to improve outcomes in DKA patients 1.
Successful transition from intravenous to subcutaneous insulin requires administration of basal insulin 2-4 hours before the intravenous insulin is stopped to prevent recurrence of ketoacidosis and rebound hyperglycemia 1.

From the Research

The treatment of DKA involves the administration of fluids and insulin, with the goal of restoring fluid balance, reducing hyperglycemia, and correcting electrolyte imbalances 2, 3, 4.
The order of administration is crucial, with fluids typically given first to restore intravascular volume and improve insulin sensitivity 2, 3.
Isotonic normal saline is often the initial fluid of choice, although balanced solutions may be used to reduce the risk of cerebral edema and promote faster DKA resolution 3.
Insulin therapy is typically initiated after fluid status has been restored and potassium levels have been normalized, with continuous IV insulin being the preferred method of administration 3, 4.
The use of an initial insulin bolus is controversial, with some studies suggesting that it may increase the risk of hypokalemia and other complications without providing a significant benefit in terms of DKA resolution 5.

Fluids are a critical component of DKA treatment, with the goal of restoring intravascular, interstitial, and intracellular compartments 2.
The choice of fluid and the rate of administration are important considerations, with isotonic normal saline being the traditional fluid of choice 2, 3.
Balanced crystalloids with restricted chloride content may be a suitable alternative, although more research is needed to fully understand their effects in DKA management 2, 3.

Insulin is a mainstay of DKA treatment, with the goal of reducing hyperglycemia and promoting the clearance of ketones 3, 4.
The optimal dose and administration of insulin are still a topic of debate, with some studies suggesting that a low-dose insulin regimen may be as effective as a standard dose regimen in terms of safety and efficacy 6.
Continuous IV insulin is generally preferred over subcutaneous insulin, although the use of an initial insulin bolus is still a topic of controversy 3, 4, 5.