Use of sodium bicarbonate and blood gas monitoring in diabetic ketoacidosis: A review

Table 1 Clinical effects of metabolic acidosis[27,28]

System	Clinical effects
Cardiovascular	Depressed myocardium contractility
	Changes in SVR
	Acidosis-aided catecholamine release opposes acidosis-mediated vasodilation.
	Net SVR depends on the sum of both effects
	Conduction defects and dysrhythmias
	Impaired response to exogenous vasopressors
Pulmonary	Increased work of breathing and respiratory failure
	Compensatory alveolar hyperventilation
	Dyspnea (Kussmaul’s breathing)
	Acute decrease in hemoglobin oxygen affinity (Bohr Effect)
	Temporary: Affinity rises after 36 h due to depletion of RBC 2,3-DPG
Renal	Pseudo-hyperkalemia
	Hyperuricemia
	Hypercalcemia
Hematological effect	Impaired coagulation
	Thrombocytopenia
	Reduced fibrinogen and thrombin formation
	Impaired clotting factor function
	Factor Va
	Factor VIIa
	Factor VIIa/tissue factor complex
Endocrine	Insulin resistance
	Catecholamine, cortisol, PTH and aldosterone stimulation
	Bone demineralization
	Protein wasting
	Free radical formation
Musculoskeletal system	Anti-anabolic effect on the bone growth centers in chronic metabolic acidosis
	Muscle fatigue
Central nerve system	Cerebral edema
	Depressed sensorium
Immune system	Impaired leukocyte function
	Increased susceptibility to infections

SVR: Systemic vascular resistance; RBC: Red blood cell; 2,3-DPG: 2,3 diphosphoglycerate; PTH: Parathyroid hormone.

Table 2 Key findings and conclusions regarding the use of sodium bicarbonate in diabetic ketoacidosis

Sodium bicarbonate use in mild to moderate acidemia (pH ≥ 7.0) is associated with

No benefit in mortality or duration of hospitalization[12]

Possible transient benefit in reversal of acidosis[12,14,16]

Delay in resolution of ketosis[18]

Trend toward worsening of central nervous system acidosis[15]

Increased need for potassium supplementation[16]

Worsened tissue hypoxia[19]

Cerebral edema and prolonged hospitalization in pediatric patients[12]

Post-treatment metabolic alkalosis

Sodium bicarbonate use in severe acidemia (pH < 7.0) has not been well-studied

No improvement in morbidity or mortality in a small, randomized trial[15]

Routine use of sodium bicarbonate in diabetic ketoacidosis is not supported by the available literature

Several situations exist in which the use of sodium bicarbonate may be warranted

Severe acidosis

Life-threatening hyperkalemia

Recovery from saline-induced metabolic acidosis

Table 3 Key findings and conclusions regarding blood gas monitoring in diabetic ketoacidosis

Venous blood is similar to arterial sampling in measuring

pH[21-25]

Bicarbonate[21,24]

Lactate[21]

Base excess[21]

Venous blood gas measurement may be used in place of arterial blood for the purposes of stratifying disease severity in diabetic ketoacidosis

Blood gas measurement does not often change management of diabetic ketoacidosis, especially when routine chemistries (including bicarbonate level) and ketone body identification are available[25]

Routine use of arterial and/or venous blood gas measurement may not be necessary in the evaluation and management of diabetic ketoacidosis

Exceptions where blood gas analysis would likely alter management include

Abnormal baseline serum bicarbonate levels

Chronic respiratory failure

Renal tubular acidosis

Acute respiratory compromise

Adequacy of respiratory compensation for metabolic acidosis

Respiratory muscle fatigue and failure