Diabetic ketoacidosis: no clear benefit from phosphate supplementation.

Clinical bottom line (level 1b-)

  1. Phosphate supplementation had no clear effect on pH, phosphate, calcium or glucose levels at 24 hours in patients with diabetic ketoacidosis.
Wilson et al: Archives of Internal Medicine 1982; 142: 517-520
Expires October 2003

The study

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

44 patients (aged range 14 to 58 years; mean 27, 50% male) diabetic ketoacidosis (defined as glucose >18 mM, pH <7.25, bicarbonate <14 mM, ketonaemia)

Excluded if
  • serum calcium >2.75 mmol/l
  • oliguria for 2-4 hours (<30 ml/hour)
  • urea >21 mmol/l or creatinine >353.6 micromol/l


    • Control Group: (n = 15, 15 analysed): no treatment
    Experimental Group: (n = 17, 17 analysed): 15 mmol phosphate (as sodium salt) given at 4 hours
    Experimental Group: (n = 12, 12 analysed): three doses of 15 mmol/ phosphate at 2, 6 and 10 hours
    All patients received insulin 0.1 unit/kg/h iv infusion and saline at a rate of 1 l/hour for the first 4 hours
    100% followed for 24 hours

    The evidence

    control vs 15 mmol
    Outcome Control Group
    (SD)    		 Experimental Group
    (SD)    		 Mean Difference
    (95% CI)
    control vs 15 mmol: phosphate levels (mmol/l) 19
    (0.6)     		2.0
    (0.6)     		-0.10
    (-0.54 to 0.33)
    control vs 15 mmol: fall in calcium levels (mmol) 0.9
    (0.6)     		1.3
    (0.9)     		-0.40
    (-0.96 to 0.16)

    control vs 45 mmol
    Outcome Control Group
    (SD)    		 Experimental Group
    (SD)    		 Mean Difference
    (95% CI)
    control vs 45 mmol: phosphate levels (mmol) 1.9
    (0.6)     		2.3
    (0.9)     		-0.40
    (-1.0 to 0.20)
    control vs 45 mmol: fall in calcium levels (mmol/l) 0.9
    (0.6)     		1.2
    (0.7)     		-0.30
    (-0.82 to 0.22)

  • No differences were observed between the three groups for the correction of glucose levels or acidosis.

    • Comments

    1. The study is mainly of historical interest only.
    2. No statistically significant differences were present between the groups at the outset of treatment in terms of glucose, potassium, renal function or acidosis (figures given in the paper). Figures for age and sex are not given though the paper reports the groups were not different in this regard.
    3. Numbers are small, so the power is limited.

    Citation

    1. Wilson HK, Keuer SP, Lea AS, et al: Phosphate therapy in diabetic ketoacidosis. Archives of Internal Medicine 1982; 142: 517-520
    Contributor: Richard Hardern and Chris Ball, July 2000
    Reviewer: Jon Levine

    Clinical Question.
    Patient DKA
    Intervention or Exposure phosphate supplementation
    Outcome pH, phosphate, calcium, glucose