MRCP2-0101

MRCP2-0101

A 68-year-old woman with a long-standing history of diabetes is referred to the Endocrinology Department with a six month history of worsening vision and numbness in her feet. She is now unable to walk more than a few steps without feeling pain and discomfort. She also reports feeling thirsty all the time and needing to urinate frequently. She is currently on metformin 1000 mg twice a day and insulin glargine 20 units once a day.
On examination in the clinic, her blood pressure (BP) is 135/80 mmHg, while her pulse is 75 beats per minute (bpm) and regular. Her fundoscopy shows evidence of diabetic retinopathy and there is reduced sensation in both feet. Her urine dipstick reveals glucose +++ and ketones -.
Which of the following measures is the most important step in this case?