You smartly recall the diagnostic criteria for DKA and realise you just need the third part:

1. Ketonaemia > 3.0mmol/L or significant ketonuria (more than 2+ on standard urine sticks)
2. Blood glucose > 11.0mmol/L or known diabetes mellitus
3. Bicarbonate (HCO3- ) < 15.0mmol/L and/or venous pH < 7.3

Even though the venous and arterial pH differs by only 0.02-0.15 pH units, you decide to put the patient through the agony of an ABG over a VBG. You very much believe in perfect data over patient wellbeing and are famous for completing your diabetic eye examination by drawing blood through the orbit from the retina for VEGF level analysis. The analyser reads:

pH 7.04

pCO₂ 2.4 kPa

pO₂ 13.6 kPa

HCO₃ 7 mmol/L

Base Excess  -11 mEq/L

Lactate 3.0 mmol/L

Na 131 mmol/L

K 4.1 mmol/L

Glucose 17.2 mmol/L

The patient’s observations are:

Pulse 111, BP 112/66 mmHg, Temp 37.1, RR 24, Sats 100% oa

What is the next step of management?

Normal saline 0.9% @ 1 Litre / 1 hour

Normal saline 0.9%  with 40 mmol KCl @ 1 Litre / 1 hour

Soluble insulin (Actrapid® or Humulin S®) @ 0.1 units/Kg/hr