Friday, July 11, 2014

Continuing medical education through conversational learning with medical school students

An illustration from our dynamic online clinical decision support forum 'tabula rasa.'
For the management of DKA
Harrison - Insulin bolus of 0.1U/kg should be given before infusion
Nelson - Insulin bolus should not be given as it predisposes to hypoglycemia
Which protocol should be followed? or is bolus harmful only for children?
  • You and Sujoy Dasgupta like this.
  • Nilanjan Sengupta better to avoid the i.v. bolus....give insulin by infusion bring down glucose slowly to avoid osmotic dysregulation (cerebral edema)
  • Durga Prasan No issues with bolus. Sometimes needed to reduce insulin resistance induced by high glucose levels.
  • Rakesh Biswas Thanks Deepanjan for raising this very interesting issue and it is heartening to see medical students tackle such challenges where text books present differences of opinion. The answer to this question is best answered by evidence around the utility of Insulin bolus in in DKA that may have been answered in the past through RCTs which we would need to search, share and discuss before validating either of the two proposed approaches or even just attribute it to assumptions such as children are likely to have different needs. I invite the expertise of Manu Mathew, Vasumathi Sriganesh, Priyank Jain to search and share and Huw Llewelyn, author of Oxford handbook of clinical diagnosis as well as an established endocrinology expert in UK to offer his system 1 opinion based on experience, clinical reasoning amalgamated with current best evidence. I would like to also invite Amy Price to summarize and thematically analyze these conversations from a 'medical cognition in the context of clinical judgement' perspective for a recent paper that we are co-authoring.
  • Amit Taneja Really, really really no difference in two approaches. Two points:1 do not bolus in kids and adolescents. 2. Be careful with the bolus dose. Do not think 0.1 unit/kg bolus dose applies to severely underweight or over weight individuals.
  • Boudhayan Dm use ur judgement..........sometimes u may be in a set up where u manage such patients on the floor ......forget an intensive care set up.....dosing needs to be adjusted based on patient characteristics.......dont blindly follow the text learning in the very short last 3 yrs of pg life
  • Boudhayan Dm dont forget fluid management and treatment of the precipitating cause
  • Boudhayan Dm Nilanjan Sengupta Durga Prasan Rakesh Biswas very happy to see my three teachers presently based in different places discussing the same topic with different points of view.......continuing my learning process
  • Huw Llewelyn Infusion allows control and can be adjusted up or down to get a desired rate of response. A bolus may increase the insulin concentration markedly for a short time but according to principles of pharmacokinetics should also result in clearance in minutes. The rate of clearance may be difficult to predict in a sick patient so a bolus will be a 'shot in the dark'. I suspect that if a RCT were carried out, there would be little difference in speed of restoration of glucose and clearance of ketones between 'the bolus+infusion arm' and 'the infusion only arm' with occasional harm from hypoglycaemia due to errors for those in the 'bolus arm'. The recent local guidelines I have seen do not mention a bolus.
  • Rakesh Biswas Here's a study from Michigan by Goyal et al that demonstrated equivalent changes in clinically relevant endpoints for those receiving bolus insulin for DKA when compared to patients not administered the bolus. The study was however not randomized or blinded.
    PubMed comprises more than 23 million citations for biomedical literature from M... See More
  • Huw Llewelyn Thank you! So there was little difference. However, it seems that the incidence of hypoglycaemia in the' bolus group' was 6% and in the 'no bolus group' it was 1%. This difference of 6 times was not 'statistically significant' for this size of study; a larger study would be needed to detect such 'occasional harm'.
  • Boudhayan Dm Deepanjan Bhattacharya pls tell us what u did in practice and its effects on the parameters of dka.........and then we can discuss more i guess
  • Huw Llewelyn Even as a junior doctor in the 1970s I never used IV boluses and have always emphasised IV infusion ever since. I also prefer IV infusion for hydrocortisone replacement in adrenal crisis but most guidelines do recommend an IV bolus initially (which is also cleared rapidly probably).
  • Rakesh Biswas Thanks Huw. Your mention of the 1970s makes me want to share this other 'medical record retrospective' study where 29 of 30 subjects treated with bolus insulin occurred before 1970. They did demonstrate a significant hypoglycemia again in the bolus insulin group.
  • Rakesh Biswas Below are summaries of two RCTs on this topic (from a journal club): Lindsay et al. The use of an insulin bolus in low-dose insulin infusion for pediatric DKA. Pediatric Emerg Care 1989;5:

    n = 38 (56 episodes DKA)


    After NS IVF bolus, randomized to +/- insulin bolus prior to insulin infusion

    No difference (time to target glucose, cerebral edema, duration insulin infusion)

    Kitabchi et al. Is a priming dose of insulin necessary in a low-dose insulin protocol for the treatment of DKA? Diabetes Care 2008;31:2081

    n = 37


    3 treatment arms (low dose insulin infusion + bolus, low dose infusion, high dose infusion)

    No difference (time to achieve normal glucose, bicarb, pH)
    Lindsay et al. The use of an insulin bolus in low-dose insulin infusion for pediatric DKA.  Pediatric Emerg Care 1989;5:

No comments: