You are asked to review a 27 year old girl, a known diabetic, admitted following a 48- hour illness characterised by nausea, vomiting and shortness of breath. She has been unable to eat or drink and has not taken her regular insulin. On examination she has a heart rate 137 /min, respiratory rate 36 breaths /min, O2 saturation is 99% on room air, blood pressure 92/34 mm Hg. She weighs 80kg and her blood sugar level is 32 mmol/l. Outline your plan of management for the first 24 hours.
This young lady most probably has diabetic ketoacidosis and is critically unwell. She requires:-
1. Resuscitation:
May need supplemental oxygen
Peripheral iv access
Commence iv fluids (hartmanns, plasmalyte, n/saline or colloid)
500ml to 1 litre stat then reassess BP/HR/RR/
blood test and ABG should be available to adjust fluid therapy
Maintenance IV fluids with N.Saline, 0.45% saline
Start 5% dextrose when BSL <15mmol/L
Monitoring:
ECG, pulse oximetry, NIBP
Early Art line and CVC
Bloods for EUC (Na+, Creat, Urea),Mg++, Phos-, Ca++, FBC, LFTs, BSL
Urine dipstick
IDC
Confirmation of diagnosis: Blood gases, a raised AG metabolic acidosis, ketones in urine/blood
2. Insulin therapy:
Insulin infusion - short acting insulin (actrapid)
Infusion Dose (candidate should provide a dosing regimen and rationale)
- 0.01 to 0.1units/kg/hr (max)
- Daily dose /24 as units per hour
Titrate to decrease in BSL 1-2 mmol/L/hr
Continue until metabolic disturbance is corrected (acidaemia and ketosis) rather than correction of BSL. May need dextrose infusion if BSL drops below normal range
3. Electrolyte replacement:
Potassium:- Start replacement when plasma K+ <5mmol/L as insulin therapy and correction of acidaemia may lead to precipitous fall and arrhythmias
Sodium:- May need to correct Na+ for BSL. Need to take care to avoid large shifts in Na as it may predispose to cerebral oedema
Bicarbonate:- almost no indication for bicarbonate therapy. Phosphate and Mg++ likely to need replacement
**Need very regular (Q2-4h) ABG and EUC for 1st 24 hours to avoid large electrolyte and BSL changes. Need regular urine dipstick q4-6h for ketones.
4. Identify and treat precipitant:
Common precipitants to consider include;
Non compliance and psycho-social issues
Infection:- gastroenteritis, UTI, respiratory tract, cholecystitis, meningitis, cellulitis
Ischaemia:- AMI, stroke, peripheral vascular disease, mesenteric ` ischaemia
Pregnancy
5. Prevention of expected complications:
Hypoglycaemia (q1h BSL, decrease insulin infusion, dextrose infusion) Hyponatraemia (regular electrolyte monitoring)
Hypokalaemia (regular electrolyte monitoring)
Hypomagnasaemia and hypophosphataemia (regular electrolyte monitoring) Venous thromboembolism (sci heparin/LMWH)
Hyperchloraemic acidosis (avoid N/saline when able)
Complications of critical illness (upper GIT bleeding, ARDS..)
Like all the management questions, this one can be dissected into manageable pieces:
Out there, every man and his dog has a protocol for the management of diabetic ketoacidosis. One Google Scholar search for "management of diabetic ketoacidosis" has yielded several pages of articles, monotonously titled "Management of diabetic ketoacidosis".
As my primary reference, I have chosen a representative statement - the "Joint British Diabetes Societies guideline. Among the various issues raised by the guideline, a few stand out as mildly interesting:
Savage, M. W., et al. "Joint British Diabetes Societies guideline for the management of diabetic ketoacidosis." Diabetic Medicine 28.5 (2011): 508-515.