Diabetic Ketoacidosis
Definition
Epidemiology
Pathophysiology
 BSL / Anion gap >10 / HCO3 <15 / pH <7.3 / moderate ketonaemia
Type I > type II; 20-30% in newly diagnosed diabetes; incidence 0.5% of diabetes; most common <18yrs;
Fetal mortality 30-50%
Risk factors for DKA in known diabetes: poor metabolic control; low socio-economic status; previous
DKA; adolescent female; psych disorder
Risk Factors for DKA in unknown diabetes: <5yrs, family history of diabetes, low socio-economic status,
meds (eg. High dose steroids, antipsychotics, immunosuppressants)
Trigger: Concurrent infection, non-compliance with meds, MI
Absolute insulin deficiency
 glucose uptake by cells
 counter-regulatory hormones – glucagon, adrenaline, growth hormon, cortisol
 gluconeogenesis,  glycogenolysis
 lipolysis  fatty acids  overproduction of acetyl co-enzyme A  ketogenesis
Acetoacetate: acetoacetate:betaHB = >6:1; measured by Ketostix urine test (>3); urinary ketones may
increase with treatment as beta-hydroxybutyrate is converted to acetoacetate
Beta hydroxybutyrate: converted peripherally to acetoacetate; prevalent in alcoholic ketoacidosis; not
detected on normal testing so ketones may be negative initially in alcoholic ketoacidosis; detected on
Medisense blood test (>3)
Acetone: from decarboxylation of acetoacetate  excreted by kidneys and lungs; detected on Acetest
(>5); responsible for ketotic breath
Amino acids, Lactate
  glucose  glycosuria, osmotic diuresis  loss of H20, Na, K, Mg, PO4  hypovolaemia and lactic
acidosis
BSL may not be  if: liver failure, alcoholic; due to impaired gluconeogenesis
Investigation
Check BSL hourly; continuous cardiac monitoring; accurate fluid balance; hourly neuro obs; U+E Q2-4hrly;
Ca, Mg, Phos, FBC ( WBC, L shift indicated lactic acidosis), lactate; Blood culture, sputum culture: if
sepsis suspected; Amylase will be factitiously increased, use lipase; Urine: ketones (positive in >95%);
culture; CT head: if altered LOC
VBG: raised anion gap metabolic acidosis; may get metabolic alkalosis from vomiting with  anion gap as
only clue of DKA; if HCO3 lower than expected for anion gap, concomitant non-anion gap metabolic
acidosis (seen in patients who are still well hydrated)
ETCO2: can be used in children; <29mmHg = 80% sensitivity
Average body fluid deficit 5-10L (ie. 100ml/kg, 10% dehydration)
Na
Correct for glucose: Na + ((Glu – 5.5) / 3)
Average Na deficit 5-10mmol/kg
K
Correct for pH:
 pH 0.1 =  K 0.5
Average K deficit 3-5mmol/kg
Osmolality
Osmolality:
(2 x Na) + Glu + Ur
Increased
Aim to  BSL by no more than 5/hr,  osmolality by 1-2/hr; endpoint: ketones cleared, normal anion
gap
Management
Mild: pH >7.3, tolerating PO fluids, <5% dehydrated  can consider treating with SC insulin only and not
down DKA route
Mod-severe: Nurse head up, NBM, NGT (if ileus), consider heparin, treat underlying cause
IVF: start within 30mins of ED arrival; aim to replace total deficit over 48hrs to avoid cerebral oedema;
caution in children, elderly, CCF, CRF; use N saline initially
Adults
Children
IV FLUIDS
1L stat (if dehydrated ++)
Using N saline:
1L over 1 hr  1L over 2hrs 
1L over 4hrs  1L over 10hrs
Add K to fluids in 2nd hour
and once UO established and K <5:
If K >5 = none
If K 4-5 = 10mmol/hr
If K 3-4 = 30mmol/hr
If K <3 = 40mmol/hr
10-20ml/kg bolus N saline
(if shocked, until haemodynamically stable)
Calculate fluid deficit
= % dehydration x weight x 10
(remember to subtract any bolus given)
…and replace deficit over 48 hours
If Na <150 / osmolality <320 – use N saline
If Na >150 / osmolality >320 – use 0.45% saline
and correct over 72hrs
When BSL <15 / if BSL <10 but ongoing ketones / if BSL decreasing by >5/hr
 use 0.45% saline + 5% dextrose, aiming for BSL 12-15
Once K <5.5, patient PU’ing, insulin infusion started
 add 40mmol KCl per 1L bag
Management
(cntd)
INSULIN
Start insulin 1hr after initial fluids (only start if K >3.4, otherwise replace K first)
0.1iu/kg/hr (max 6iu/hr) actrapid
 insulin to 0.05iu/kg/hr when BSL <12 and acidosis improving
aiming BSL 9-14; if BSL still too low despite this, can strop infusion for 10-15mins only
 insulin to 0.05iu/kg/hr for 4 hours if K <3
Criteria for change to SC:
BSL <11, HCO3 >16-18, pH >7.3, anion gap <15, eating and drinking, normal LOC, ketones cleared;
when stopping, give mixed short and long acting SC dose at least 1 hour before stopping infusion
OTHERS
Phosphate / Mg: only if severe / symptomatic  in phosphate / Mg
K2PO4 5mmol/hr
MgSO4 2.5g over 1hr
HCO3: only if pH <7, HCO3 <5, life-threatening hyperkalaemia, coma,
haemodynamic compromise unresponsive to fluid resus
May cause rapid  K, worsened intracellular acidosis, impaired offloading of O 2, Na overload,
hypertonicity, cerebral oedema (4x  risk), volume overload, paradoxical CNS acidosis
HCO3 mmol = 0.15 x base deficit x kg
or
0.5-2mmol/kg over 1-2hrs
Endpoint: pH >7.1, HCO3 >10
Admit ICU if: In children: <2yrs, pH <7.1, altered LOC, need for arterial line,
severe hyperosmolar dehydration
Discharge
Patient education ( insulin by 4iu or more when intercurrent illness, even if not eating)
Prognosis
Mortality 5-15% (0.3-1% in children) - due to underlying disease, cerebral oedema, thromboembolism
Poor prognostic factors: ARF, altered LOC, hypotension
Complications
Cerebral
Oedema
 BSL,  K,  phosphate, ARDS, recurrence, thrombosis
Leading cause of mortality from DKA; 70% mortality; 10% survivors have permanent neuro sequelae;
more common in children (1% incidence)
Risk factors: 1st presentation; long history poor control; <5yrs; initial corrected Na >160; severe 
osmolality; persistent hypoNa; severe acidosis; ??related to overaggressive fluid resus
Symptoms: onset 4-12hrs after starting treatment; headache,  Na, altered LOC,  HR, HTN,  RR,
incontinence, pupil changes, seizures, papilloedema
Treatment: 0.5-1g/kg mannitol IV bolus / 5-10ml/kg 3% saline IV over 30mins; give half maintenance
fluids; admit PICU; neurosurg review; CT; hyperventilate if ETT
Differential Diagnosis: cerebral venous sinus thrombosis (may require contrast CT / MRI for detection if
initial CT normal)
Differential
Diagnosis
Ethylene glycol, isopropyl alcohol, salicylates
Other Crises
New onset hyperglycaemia but no DKA: give 0.1iu/kg SC regular insulin; admit
Hyperglycaemia, known diabetes, no DKA: give additional 10% of normal daily insulin dose as regular
insulin SC