DKA Flashcards
What is the definition of diabetic ketoacidosis?
biochemical triad of ketonaemia (ketosis), hyperglycaemia and acidaemia
What is the pathophysiology of diabetic ketoacidosis?
- consequence of absolute or relative insulin deficiency, accompanied by an increase in counter-regulatory hormones (glucagon, cortisol, growth hormone, catcholamines)
- hormonal imbalance enhances hepatic gluconeogenesis and glycogenolysis → severe hyperglycaemia
- enhanced lipolysis increases serum free fatty acids; metabolised as an alternative energy source in the process of ketogenesis, resulting in accumulation of large quantities of ketone bodies and therefore metabolic acidosis
What are 3 examples of ketones and which is the predominant one in DKA?
- 3-beta-hydroxybutyrate → predominant
- Acetone
- Acetoacetate
Which type(s) of diabetes may result in DKA?
considered to previously be T1 but increasingly seen in T2 too
What are 3 causes of the fluid depletion in DKA?
- Hyperglycaemia causing osmotic diuresis
- Vomiting - common in DKA
- Inability to take in fluid due to diminished level of consciousness
What electrolyte abnormalities during DKA are most important to look out for?
hypokalaemia and hyperkalaemia
What is the most comon cause of mortality in DKA in young children and adolescents?
cerebral oedema
What are the 3 most comon cause of mortality in DKA in adults?
- Hypokalaemia
- Adult respiratory distress syndrome
- Co-morbid states e.g. pneumonia, acute MI, sepsis
What 3 key things is a diagnosis of DKA based on?
- Ketonaemia >3.0 mmol/L or significant ketonuria (>2+ on standard urine sticks)
- Blood glucose > 11.0 mmol/L or known diabetes mellitus
- Bicarbonate (HCO3+) < 15.0 mmol/L and/or venous pH <7.3
What is euglycaemia diabetic ketoacidosis?
when patients present with modest elevation of bloo glucose but with an acidosis secondary to ketonaemia
What is the best practice for monitoring response to treatment of DKA and why?
measurement of blood ketones - as resolution of DKA depends on the suppression of ketonaemia
What are the 5 key aspects of bedside monitoring in DKA?
- Blood glucose
- Bloode ketones
- Electrolytes - including bicarbonate
- Venous pH
When should the diaetes specialist team be involved in DKA?
should be involved in care of all admitted to hospital with DKA
Are arterial or venous pH + bicarbonate recommended to be measured as treatment markers?
venous
When should the diabetes specialist team be involved in DKA?
as soon as possible
What is the recomended maximmum initial insuli infusion rate for DKA?
15 uits per hour
What is th definition of resolution of DKA?
- pH >7.3
- Bicarbonate >15.mmol/L
- Blood ketones <0.6 mmol/L
What type of long-acting insulin should newly presenting type 1 patients be given for their basal insulin dose?
Lantus or Levemir at dose of 0.25 units per kg, once daily subcutaneously
What are the 3 min aims for fluid replacement in DKA treatment?
- Restoration of circulatory volume
- Clearance of ketones
- Correction of electrolyte imbalace
What are the 3 aims of the first few litres of fluid when administered to treat DKA?
- Correct any hypotension
- Replenish the intravascular deficit
- Counteract the effects of the osmotic diuresis with correction of the electrolyte disturbance
What is the recommended insulin therapy following commencement of IV fluids in DKA?
fixed rate insulin infusion (FRII) calculated on 0.1 units/kilogram body weight (may be necessary to estimate weight of patient)
What are the 3 most important effects of IV insulin when treating DKA?
- Suppression of ketogenesis
- Reduction of blood glucose
- Correction of electrolyte disturbance
What are 4 metabolic treatment targets when treating DKA?
- Reduction of the blood ketone concentration by 0.5mmol/L/hour
- Increase the venous bicarbonate by 3.0mmol/L/hour
- Reduce capillary blood glucose by 3.0mmol/L/hour
- Maintain potassium between 4.0 and 5.5mmol/L
What is often required as part of DKA treatment in order to avoid hypoglycaemia, so that FRII can be conftinued?
infusion of 10% glucose
When should IV glucose 10% infusion be started?
when blood glucose falls below 14.0 mmol/L
How long should IV glucose 10% infusion be continued in the treatment of DKA?
until patient is eating and drinking normally
What are 5 special patient groups who need specialist input ASAP if DKA occurs and special attention to fluid balance?
- Elderly
- Pregnant
- Young people 18 to 25 years of age
- Heart or kidney failure
- Other serious comorbidities
What are 9 patient education considerations following DKA, to be counselled on usually by the diabetes specialist team?
- Identify precipitating factor (infection, omission of insulin injections)
- Review of usual glycaemic control
- Review of injection technique/ blood glucose monitoring/ equipment/ injection sites
- Prevention of recurrence e.g. provision of written sick day rules
- Insulin ineffective e.g. patient’s own insulin may be expired or denatured, should check
- Assess need for home ketone meters
- Provide contact number on how to contact diabetes specialist team out of hours
- Educate health care professionals on managing ketonaemia
- Provide written care plan
What is the recommended fluid of choice for fluid resuscitation in DKA?
crystalloid: 0.9% sodium chloride solution
Should bicarbonate administration be routinely used to treat DKA?
no
What are the 3 key things you are looking for on a venous blood gas?
pH, bicarbonate, potassium
What is the risk of rapid fluid repacement in DKA?
cerebral oedema
In which particular patients is cautious fluid replacement in DKA recommended to avoid cerebral oedema?
small young adults who are not shocked at presentation
What is the recommendation about continuation of long-acting insulin during the treatment of DKA?
evidence suggests continuation of pre-existing prescriptions is safe (does not obviate need to give short-acting insulin before discontinuing IV insulin infusion)
What would be the dose of fixed rate insulin infusion started in a 70kg patient in DKA?
7 units/ kg/ hour
Why is giving IV carbonate not routinely recommended in DKA?
- excessive amounts may cause rise in CO2 partial pressure in the CSF and may lead to paradoxical increase in CSF acidosis
- may also delay the fall in blood lactate
- may be implicated in development of cerebral oedema in chidren and young adults
What is the only situation when phosphate replacement should be considered in DKA?
- presence of respiratory and skeletal muscle weakness
What are the 4 serious complications of DKA and its treatment to be aware of?
- Hypokalaemia and hyperkalaemia
- Hypoglycaemia
- Cerebral oedema
- Pulmonary oedema
When and how should potassium be prescribed in the management of DKA?
- should not be prescribed with initial fluid resuscitation or if serum potassium level remains above 5.5 mmol/L
- 0.9% sodium chloride with potassium 40 mmol/L (ready mixed) should be prescribed as long as the serum potassium level is below 5.5 mmol/L and patient is passing urine
When does the potassium regimen in the treatment of DKA need review?
if serum potassium falls below 3.5 mmol/L
What may be a consequence of hypoglycaemia due to treatment of DKA with FRII?
- hypoglycaemia may result in a rebound ketosis driven by counter-regulatory hormones, which lengthens the duration of treatment
- severe hypoglycaemia also associated with cardiac arrhythmias, acute brain injury and death
How common is cerebral oedema when treating DKA in adults?
symptomatic cerebral oedema relatively uncommon in adults, but asymptomatic cerebral oedema may occur commonly
What is thought to be the mechanism of cerebral oedema?
exact cause unknown, suggested due to cerebral hypoperfusion with subsequent reperfusion
What is thought to increase the risk of pulmonary oedema when treating DKA?
rapid infusion of crystalloids over a short period of time
Which patient group is at particular risk of pulmonary oedema?
elderly patients and those with impaired cardiac function
What are 9 indicators of severe DKA?
- Blood ketones >6mmol/L
- Bicarbonate level <5mmol/L
- Venous/arterial pH <7.0
- Hypokalaemia on admission (under 3.5mmol/L)
- GCS less than 12 or abnormal AVPU scale
- Oxygen saturation <92% on air (assuming normal baseline respiratory function)
- Systolic BP below 90mmHg
- Pulse over 100 or below 60bpm
- Anion gap above 16 [Anion Gap = (Na+ + K+) – (Cl- + HCO3 - )]
What should be done if there are any signs of severe DKA present?
review by consultant physician, consider for referral to Level 2/HDU environment
If bedside ketone monitoring is not available, what can instead be used to assessed response to DKA treatment during the first 6 hours?
venous bicarbonate
What are the 5 key steps of management during the initial (first hour) of treatment of DKA?
- A-E assessment, including IV access + bloods
- Fluid: NaCl 0.9%,to replace deficit (1L over 1st hr, then 1L over 2,2,4,4,6)
- unless systolic <90 mmHg, then give bolus 500ml over 15min
- Potassium replacement - depending upon level (usually after 1st hour only)
- FRII 0.1 unit/kg/hour (7 units/ hour if 70kg) via infusion pump with NaCl
- Glucose 10% at 125ml/hour if falls below 14 mmol/L (likely to be later on)
What is the monitoring regime in DKA for blood glucose, ketones, potassium and bicarbonate?
- blood glucose: hourly
- ketones: hourly
- potassium and bicarbonate: 2 hourly (at least) for first 6 hours
What are the steps to ABCDE assessment in suspected DKA?
- A: assess airway
- B: breathing: resp rate, sats, examine chest (?Kussmaul breathing)
- continuous pulse oximetry
- C: circulation
- large bore IV cannula - commence IV fluid replacement NaCl 0.9%
- venous plasma glucose, U+Es, VBG, FBC, blood cultures
- blood glucose
- blood ketones
- ECG
- continuous cardiac monitoring
- urinalysis + culture
- CXR if indicated
- D:
- temperature
- GCS - drowsy = critical care input needed. consider NG tube with airway protection to prevent aspiration
- E: full clinical examination
What are 8 investigations to perform in the C part of ABCDE in DKA?
- Blood ketones
- Capillary blood glucose
- Venous plasma glucose
- Urea + electrolytes
- VBG
- FBC
- Blood cultures
- ECG + continuous cardiac monitoring
What are 2 key things to address in the history of someone with suspected DKA?
- possible precipitating cause (chest infection, MI, UTI, missed insulin)
- establish usual medication for diabetes
What can give indicators as to the severity of dehydration in DKA?
pulse nad blood pressure - 90mmHg can be used as measure of hydration (but take age, gender and concomitant medication into account)
If systlic BP on admission in below 90mmHg in DKA, what should be done?
- give 500ml of 0.9% sodium chloride solution over 10-15 minutes
- if remains <90, can repeat this while awaiting senior input
- most patients require 500-1000ml given rapidly
- if no clinical improvement, reconsider other causes of hypertension, seek immediate senior assessment. consider involvement of ITU/ critical care team
- once SBP >90, follow fluid replacement as for all DKA cases
What is the regimen of fuid resuscitation that is given in DKA?
- 1st hour: 0.9% sodium chloride 1L / 1st hour
- 0.9% sodium chloride 1L with potassium chloride: 1L/ 2 hours
- 0.9% sodium chloride 1L with potassium chloride: 1L/ 2 hours
- 0.9% sodium chloride 1L with potassium chloride 1L/ 4 hours
- 0.9% sodium chloride 1L with potassium chloride: 1L/ 4 hours
- 0.9% sodium chloride 1L with potassium chloride: 1L/ 6 hours
reassessment of cardiovasculra status at 12 hours is mandatory, further fluid may be required
What does whether you add potassium to the saline fluid infusion after the first hour of treatment depend on?
- based upon potassium level on VBG :
- <3.5 mmol/L: senior review as additional potassium needs to be given
- 3.5-5.5 mmol/L: 40 mmol added to each litre
- >5.5: nil
How is a FRIII commenced, once the saline fluid infusion has been started?
- start continuous FRIII via infusion pump
- made of 50 units of human soluble insulin (Actrapid, Humulin S) made up to 50ml with 0.9% sodium chloride solution
- should ideally provided as ready-made infusion
- infuse at fixed rate of 0.1 unit/ kg/ hour
What is the only time when you would give a bolus (stat) dose of insulin when treating DKA?
can give IM insulin 0.1 unit/kg if there is delay in settign up FRIII
What is the aim for the rate of fall of ketones when treating DKA?
0.5 mmol / hour
What is the aim for change in bicarbonate during the treatment of DKA?
should rise by 3.0 mmol/L / hour
What is the aim for change in blood glucose during treatment of DKA?
should fall by 3.0 mmol/ hour
How frequently should patients be reviewed during DKA treatment?
houlry - ketone + glucose concentrations
When would you consider urinary catheterisation in a patient in DKA?
if incontinence or anuric (not passed urine by 60min)
What should you do if the patient is persistently vomiting?
consider NG tube insertion
What should you do if a patient in DKA’s o2 sats fall?
ABG measurement, request repeat CXR
What is the minimum urine output that the patient should be achieving on the fluid balance chart?
0.5ml/kg/hr
When monitoring blood glucose levels, what should be done if the meter reads ‘Hi’ or ‘>20 mmol/L’?
venous blood should be sent to the laboratory hourly or measured using venous blood in blood gas analyser
What should be done if blood ketone measurement is not falling by at least 0.5 mmol/L per hour?
increase insulin infusion rate by 1.0 unit/hr increments hourly, until ketones falling at target rates
What are the 4 key actions during the period 60 minutes to 6 hours of DKA treatment?
- Re-assess patient, monitor vital signs
- Review metabolic parameters
- Indentify and treat precipitating factors
- Give patients with newly diagnosed type 1 diabetes Lantus or Levemir at dose of 0.25 units/kg subcut once daily (to mitigate against rebound ketosis once FRIII stopped)
What should always be checked if ketones and glucose are not falling as expected during the treatment for DKA?
check insulin infusion pump is working and connected and that the correct insulin residual volume is present (to check for pump malfunction)
Why can’t bicarbonate be used as a surrogate for pH at 6-12 hours into the treatment of DKA?
the hyperchloraemic acidosis associated with large volumes of 0.9% sodium chloride will lower bicarbonate levels
By what period would you expect the ketonaemia and acidosis to resolve in DKA?
by 24 hours
At 24 hours what should you do if the patient is not eating and drinking?
continue IV fluids and move to VRIII
At 24 hours into DKA treatment, what should you do if the patient is eating and drinking normally?
Transfer to subcutaneous insulin - start before IV insulin discontinued
ideally give subcut fast-acting insulin at a meal, discontinue IV insulin 1hr later
How can hyperchloraemic acidosis cause oliguria?
may cause renal vasoconstriction
What should be done if DKA has not resolved by 24 hours?
senior and specialist input needed
Who ideally mnages the conversion to subcutaneous insulin after treatment for DKA?
the diabetes specialist team
What must be prescribed prophylactically when managing DKA?
low molecular weight heparin - enoxaparin, dalteparin due to VTE risk
