Diabetic ketoacidosis: no clear role for bicarbonate.

Clinical bottom line (level 1b-)

  1. Patients with severe diabetic ketoacidosis who received bicarbonate did not clearly return more quickly to biochemical stability.
  2. The effect on hypokalaemic or hypoglycaemic episodes was unclear.
Morris et al: Annals of Internal Medicine 1986; 105: 836-840
Expires October 2003

The study

Unblinded concealed randomised trial with intention-to-treat
Setting: urban university hospital, USA

21 patients (aged mean 30 years, ?% male) severe diabetic ketoacidosis (defined as plasma glucose = 14 mmol/l, ketonaemia, serum bicarbonate level = 15 mmol/l, arterial pH 6.9 to 7.14)

Excluded if
  • mild acidosis ( = 7.15) or extreme acidosis (<6.9)
  • severe concomitant medical problems
  • aged <15
  • pregnancy


    • Control Group: (n = 10, 10 analysed): no intervention
    Experimental Group: (n = , analysed): bicarbonate 133.8 mmol if initial pH 6.9-6.99; 89.2 mmol if initial pH 7.0-7.09; 44.6 mmol if initial pH 7.1-7.14. Bicarbonate was infused over 30 minutes and repeated every two hours until pH = 7.15.
    All patients had insulin (bolus 0.15 U iv and 0.15 U im initially then 7 U hourly im), and fluids (0.9% or 0.45% saline at 250 to 1000 ml/hour).
    100% followed for 24 hours

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    hypoglycaemia 24 hours 1
    (10.0%)    		 0
    (0.00%)    		 100%
    (-173% to 100%)    		 10.0%
    (-8.59% to 28.6%)    		 10
    (NNT = 3 to infinity;
    NNH = 12 to infinity)

    Outcome Control Group
    (SD)    		 Experimental Group
    (SD)    		 Mean Difference
    (95% CI)
    time to glucose <14 mmol/l (hours) 4.2
    (3.2)     		4.9
    (4.3)     		-0.70
    (-4.2 to 2.8)
    time to pH 7.3 or more (hours) 15.6
    (7.9)     		13.1
    (8.3)     		2.5
    (-4.9 to 9.9)
    time to bicarbonate 15 mmol/l or more (hours) 21
    (13)     		21
    (14)     		0.0
    (-12 to 12)

  • The rate of change in blood pH, potassium, ketones and bicarbonate did not differ between the two groups (shown on graphs but no numerical data reported).
  • No patient had an episode of hypokalaemia.

    • Citation

    1. Morris LR, Murphy MB, Kitabchi AE: Bicarbonate therapy in severe diabetic ketoacidosis. Annals of Internal Medicine 1986; 105: 836-840
    Contributor: Richard Hardern and Chris Ball, July 2000
    Reviewer:

    Clinical Question.
    Patient severe DKA
    Intervention or Exposure bicarbonate
    Comparison no intervention
    Outcome hypokalaemia or hypoglycaemia