diabetic ketoacidosis Flashcards
definition of DKA
acute metabolic complication of dm
requires prompt med attention
absolute insulin deficiency and most common acute hyperglycaemic complication of t1dm
pathology of diabetic ketoacidosis
ketoacidosis is alternative metabolic pathway used in starvation - less efficient than metabolism of carbs, and produces acetone = fruity breath
in diabetic ketoacidosis - low insulin and high counterregulatory hormones = high hepatic gluconeogenesis (=high glucose) and low peripheral glucose utilisation
=starvation like state
= combination of acidosis and hyperglycaemia = deadly
renal reabsorbative capacity of glucose is exceeded = glycosuria, osmotic diuresis and dehydration
increased lipolysis = ketogenesis and metabolic acidosis
precipitations of diabetic ketoacidosis
infection eg UTI
errors in dm management
newly diagnosed dm
other medical disease: MI, pancreatitis
chemo
angtipsychotics
surgery
idiopathic
presenting symptoms of diabetic ketoacidosis
gradual drowsiness
vomiting
dehydration
unexplained vomiting
abdo pain
polydipsia
lethargy
anorexia
signs of diabetic ketoacidosis
ketotic breath (fruity)
dehydration
coma
kussmaul hyperventilation
investigations for diabetic ketoacidosis
ECG
CXR
dipstick and MSU
Blood: capillary and lab glucose, ketones, pH (VBG - only ABG oif low GCS/hypoxia), UE, osmolarity, bicarb, FBC, blood culture
diagnosis of DKA
acisosis - venous blood <7.3 or bicarb <15mmol/L
hyperglycaemia - bloog glucose >11mmol/L or known dm
ketonaemia >3mmol/L, sig ketonuria (more than 2+ on dipstick)
management of DKA
large bore cannular - saline (start with 1L over 1hr)
give human soluble insulin (add to the saline), continue pts normal long acting insulin
aim for fall in ketones of 0.5mmol/L/h or rise in venous bicarb by 3mmol/L/h and fall in glucose of 3mmol/L/hr - if not increqse insulin
check cap glucose and ketones hourly
check VBG
assess need for K (falls as enters cells, add according to VBG not to 1st bag)
consider catheter
avoid hypoglycaemia - when glucose <14mmol/L strart glucose infusion with saline
continue fixed rate insulin until ketones <0.6mmol/L venous pH >7.3, and venous bicarb >15mmol/L.
find and treat cause
severe DKA
Blood ketones >6mmol/L.
Venous bicarbonate <5mmol/L.
Venous/arterial pH <7.0.
K <3.5mmol/L on admission.
GCS <12.
- O2 sats <92% on air (assuming no respiratory disease).
- Systolic BP <90mmHg.
- Pulse >100 or <60 bpm.
- Anion gap above 16
management of severe dka
if one of features of severe DKA present - consider transfer to HDU/ICU for monitoring and central venous access
get senior help
complications of DKA
cerebral oedema - get help if sudden CNS decline
aspiration pneumonia
hypokalaemia
hypomagnesaemia
hypophosphtaemia
thromboembolism
prognosis of DKA
life threatening
mortality rates are decreasing
death rare from metabolic complications - instead from underlying illness
prognosis worse at extremes of age and in presense of coma and hypotension
pitfalls of DKA
plasma glucose - usually high, not always (esp if insulin continued)
high WCC - maybe in abscence of infection
infection - often no fever, do MSU, blood cultures, CXR, start broad spectrum AB (co-amoxiclav) early
creatinine - some assays for creatinine cross-react with ketone bodies, so plasma creatine may not reflect true renal function
hyponatraemia - common due to osmolar compensation for hyperglycaemia, high/normal Na = severe water loss. with treatment Na rises as water enters cells. Na+ is also low due to an artefact; corrected plasma [Na+] = Na+ + 2.4[(glucose = 5.5)/5.5].
ketonuria doesnt equate with ketoacidosis - anyone may have 2_ ketonuria on an overnight fast. Not all ketones are due to dm - consider alcohol if glucose normal. Check venous blood ketones
recurrent acidosis - blood glucose may return to normal before all ketones removed from the blood, premature stopping of isnulin can = lack of ketone clearance and retunr to DKA. avoided by maintaining constant rate of insulin infusion (with co-infusion of glucose 10% to maintain plasma glucose at 6–10mmol/L) until blood ketones 7.3
acidosis - but w/o gross elevation of glucose can occur, but consideer OD (eg aspirin) and lactic acidosis (in elderly diabetics)
serum amylase - often raised upt op 10x and non-specific abdo pain is common, even in absence of pancreatitis
epidemiology of DKA
incidence increasing
normally in T1dm
one-year incidence of 3.6% among people with type 1 diabetes.
one-year incidence of 3.6% among people with type 1 diabetes.
Ketosis-prone type 2 diabetes tends to be more common in older, overweight, non-white people with type 2 diabetes, and DKA may be their their first presentation of diabetes
