Diabetic Ketoacidosis (Adults)

Definition: A major life threatening metabolic condition occurring in diabetic patients leading to hyperglycaemia, ketoacidosis, dehydration and ketonuria.

Pathophysiology: 
The lack of insulin primarily leads to hyperglycaemia and ketonaemia: 

• Insulin insufficiency leads to reduced uptake of glucose into cells and increased blood concentration of glucose. 
• As glucose are not taken into cells, alternative sources of energy are used. 
• Most cells break down fatty acids instead of glucose which forms ketones. Ketone levels therefore reflects the glucose deficit in cells. 
• Lack of insulin also leads to an increase in opposing hormones which lead to increased glycogenolysis, gluconeogenesis and lipolysis. 

• Lipolysis produces fatty acids and ketone bodies which can be used for energy production. The breakdown of fatty acids also produce ketones. 
• When the rate of ketone production exceeds the rate of ketone consumption ketonaemia and ketonuria occurs. 

The excess ketones and glucose in the blood leads to diuresis 

• Initially an increased glucose leads to a shift of intracellular fluid to the extracellular space (diluting the glucose concentration in blood) 
• Excess glucose cannot be reabsorbed quick enough by the kidneys. This leads to water loss through osmosis. 
• Sodium, potassium, ketones, and phosphates are lost along side this. 

Ketones also dissociate to cause a metabolic acidosis

epidimiology: 
5-8 episodes per 100 patient diabetic years.
May be first sign of diabetes or percipitated by another event/poor compliance. 

Precipitant	Occurrence (%)
Infections (commonly urinary tract)	30
Non-compliance with treatment	15
New diagnosis of type I diabetes	5-15
Other stresses (MI, alcohol, pancreatitis, drugs)	5
No cause found	40

Presentation: 

• Thirst 
• Polyuria

Others include: 

• Weight loss
• Weakness and lethargy 
• Abdominal pain
• Nausea and vomiting
• anorexia

Signs

• dehydration - dry skin, loss of skin turgor, dry mucous membranes, 
• signs of shock - tachycardia/hypotension
• Temperature is usually normal 
• Compensation for metabolic acidosis- kussmaul's breathing (rapid deep breathing)  
• Ketotic breath
• Altered conciousness

Also look for signs of concurrent illnesses - eg. infection, pancreatitis, MI etc

Differential diagnosis

Hyperosmolar hyperketoic state (tends to be type 2 - no marked ketonaemia) 

Alcoholic ketoacidosis

Diabetic ketoacidosis is diagnosed by: 

• blood sugar greater than 11mmol/L or known diabetes mellitus
• presence of urinary or plasma ketones - 2+ on dipstick or over 3mmol/L in plasma sample
• a venous pH less than 7.3 or a venous bicarbonate of less than 15 mmol/l

Investigations:
Urine

dipstick-  ketones

Mid stream urine cultures 

Bloods: 

capillary blood glucose 

Venous blood glucose

serum beta-hydroxybutyrate (ketone) 

U+Es

FBC

blood cultures

amylase

Venous or arterial blood gases. 

Imaging

Chest x ray

Functional

ECG

Management 

(click to enlarge: also available at http://www.bsped.org.uk/clinical/docs/jbdsdkaguidelines_may11.pdf) 

1. Airway, Breathing, Circulation, Disability assessment
2. Determine diagnosis 
3. Give 100% oxygen with a reservoir bag + start cardiac monitoring/ regular pulse and blood pressure/sats
4. Gain IV access with wide bore cannula in both arms - take bloods. 
5. Start fluids - 0.9% at 15-20mls/kg (or 1-1.5 L/h) for the first hour - add potassium if potassium is low (20-40mmol). 
6. Start IV insulin 0.1 units/kg/h for the first hour if blood potassium normal. (maximum of 15units per hour for those morbidly obese) 

Admission to HDU or ITU should be considered if the following are present: 
(i) blood ketones over 6 mmol⁄l;
(ii) bicarbonate level below 5 mmol⁄l;
(iii) venous⁄arterial pH below 7.1;
(iv) hypokalaemia on admission (under 3.5 mmol⁄l);
(v) Glasgow Coma Scale (GCS) less than 12 or abnormal
AVPU (Alert, Voice, Pain, Unresponsive) scale;
(vi) oxygen saturation below 92% on air (assuming normal
baseline respiratory function);
(vii) systolic blood pressure below 90 mmHg;
(viii) pulse over 100 or below 60 b/min)
(ix) anion gap above16 

60 min- 6 hours 

1. Assess hydration , estimate dehydration, calculate corrected sodium
2. Continue fluid resus at 4-14 mls/h aiming to replace lost volume over 24 hours at 0.9 % if corrected sodium is low and 0.45% if high or normal. 
3. Reassess blood glucose and blood ketones hourly - aim for a blood glucose fall of 3 mmol/L/hr, a fall in ketones of 0.5mmol/L per hour and a rise in bicarbonate of about 3 mmol/L/hr. Adjust insulin as needed to achieve this.  When glucose falls below 14mmol/L add 10% dextrose to fluids.
   Insulin aims to correct ketone levels by providing cells with glucose as well as reducing blood glucose levels. This is why glucose is added when glucose levels are low before ketone levels have become normal rather than insulin being reduced. 
4. and venous blood gases (pH, potassium, and bicarb) hourly. If potassium levels are appropriate after 2nd hour, check every 2 hours. 
5. Consider underlying causes and additional needs : 

• Preform ECG, Chest X ray etc. 
• Start accurate fluid balance chart - urinary catheterisation
• Nasogastric tube if unconcious or vomiting
• Thromboprophylaxis with heparin should be started
• If underlying infection is found treat with antibiotics. 

6 hours + 

Continue monitoring serum ketones and glucose. When ketone levels are back to normal and acidosis has resolved, patient can be encouraged to eat normally and treatment can be changed to subcutaneous insulin via a sliding scale system. 
Avoid hypoglycaemia

Assess for possible complications such as cerebral oedema and fluid overload and adjust treatment accordingly. 

Refer to diabetic team/advise on long term treatment - discuss with the patient causes of DKA, and educate patient, such as setting up 'sick day' rules. Provide meters to measure ketones if available. 

http://totw.anaesthesiologists.org/2009/04/06/diabetic-ketoacidosis-128/

http://www.cmft.nhs.uk/media/383957/dka%20guidelines%20-%202012.pdf

http://emedicine.medscape.com/article/116820-overview#a0104

http://emedicine.medscape.com/article/1914705-overview

Dr Fred Roberts, presentation on starvation, Royal Devon and Exeter hospital.
http://www.bsped.org.uk/clinical/docs/jbdsdkaguidelines_may11.pdf