Diabetic ketoacidosis: increased infection rates with phosphate infusions.

Clinical bottom line (level 1b)

  1. Patients with diabetic ketoacidosis or nonketotic hyperosmolar coma who received phosphate infusions were less likely to be hypophosphataemic at 48 hours (NNT = 3 at 48 hours) , but were more likely to have an infection during their admission (NNH = 2 at unknown) .
  2. The effect on mortality was unclear.
  3. Patients given phosphate infusions did not recover consciousness more quickly nor leave hospital sooner.
Keller and Berger: Diabetes 1980; 29: 87-95
Expires October 2003

The study

Unblinded concealed randomised trial with intention-to-treat
Setting: medical intensive care unit, university hospital, Switzerland

40 patients (aged range 16 to 85 years, 55% female) diabetic ketoacidosis (60%; defined as positive plasma ketones at a dilution of 1:2, pH <7.25, plasma glucose >22 mmol/l) or nonketotic hyperosmolar coma (defined as glucose 31 mmol/l and osmolality >340 mOsmol/kg)
Control Group: (n = 22, 22 analysed): no phosphate infusion
Experimental Group: (n = 18, 18 analysed): phosphate infusion 40-130 mmol/l. Non-ketotic patients received lower doses
All patients had iv fluids and insulin, and potassium as required.
100% followed for ?
Outcome notes:
  • hypophosphataemia : phosphate <0.65 mmol/l

The evidence

Outcome Time to outcome CEREERRRR
(95% CI)		ARR
(95% CI)		NNT
(95% CI)
hypophosphataemia 48 hours 8
(36.4%)		 1
(5.56%)		 85%
(-11% to 98%)		 30.8%
(8.09% to 53.5%)		 3
(2 to 12)
infection . unknown 7
(31.8%)		 13
(72.2%)		 -127%
(-346% to -16%)		 -40.4%
(-68.8% to -12.0%)		 -2
(-8 to -1)
death unknown 3
(13.6%)		 2
(11.1%)		 19%
(-340% to 85%)		 2.53%
(-17.9% to 22.9%)		 40
(NNT = 6 to infinity;
NNH = 4 to infinity)

Outcome Control Group
(SD)		 Experimental Group
(SD)		 Mean Difference
(95% CI)
time to full consciousness (hours) 18
(19) 		24
(25) 		-6
(-20 to 8)
time to discharge (days) 22
(19) 		23
(13) 		-1
(-12 to 9.7)

Citation

  1. Keller U, and Berger W: Prevention of hypophosphatemia by phosphate infusion during treatment of diabetic ketoacidosis and hyperosmolar coma. Diabetes 1980; 29: 87-95
Search Terms: ketoacid* in Cochrane
Contributor: Chris Ball and Clare Wotton, July 2000
Reviewer:

Clinical Question.
Patient DKA
Intervention or Exposure phosphate
Outcome hypophosphataemia