Question 7

You are called to assist with the management of a 5-month-old, 6 kg female infant who has been brought into the Emergency Department of your small rural hospital with a 4-day history of diarrhoea and vomiting.

On review, she is drowsy, mottled and cold with a heart rate of 155 beats/min and blood pressure 72/37 mmHg.

Her arterial blood results are as follows:

Parameter	Patient Value	Normal Adult Range
Fi02	0.5
pH	6.90*	7.35 - 7.45
PC02	44 mmHg (5.8 kPa)	35 - 50 (4.9 - 6.6)
P02	41 mmHq (5.4 kPa)
Bicarbonate	8.5 mmol/L*	22.0 - 28.0
Base Excess	-20 mmol/L*	-2 - +2
Sodium	146 mmol/L*	135 - 145
Potassium	6.2 mmol/L*	3.5 - 5.0
Chloride	110 mmol/L	100 - 110
Glucose	2.2 mmol/L*	3.0 - 5.4
Calcium ionised	1.13 mmol/L	1.12 - 1.32
Urea	31.0 mmol/L*	3.0 - 8.0
Creatinine	305 umol/L*	45 - 90

Outline the principles of management for this infant.

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College answer

Concurrent resuscitation, assessment and treatment of this extremely sick child, addressing the hypotension, acute kidney injury, severe shock and dehydration and profound metabolic derangement.

Stabilisation of the child prior to transfer to a tertiary paediatric institution with close liaison with paediatric team for advice on management.

Use Broselow tape, guidelines on paediatric drug doses, dedicated paediatric resuscitation equipment etc. to ensure appropriate doses of fluids and drugs, tube sizes, ventilator settings etc.

Steps in management

Call for help
Assess airway and breathing o inadequate ventilation, depressed level of consciousness, profound dehydration and shock
100% oxygen and support ventilation with BVM if required. This child will need intubation but need to optimise cardiac output before proceeding with this (consider waiting until transport team arrive for maximum support)
Establish venous access, IO line or peripheral venous (central venous access only if second person available to perform or if child more stable)
Immediate treatment of hypoglycaemia with 2 – 5 ml/kg 10% dextrose. Ongoing glucose to maintain blood sugar levels measured hourly at the very least.
Ongoing volume resuscitation with 10 – 20 ml/kg boluses of 0.9% sodium chloride, reassess perfusion and repeat as needed. Some children require up to 100 ml/kg fluid resuscitation (caution if cardiogenic shock present)
Electrolyte replacement as required
Ongoing maintenance fluid – e.g. add 100 ml of 50% dextrose to 900 ml 0.9% NaCl and infuse this at 2/3 maintenance rate (16 ml/hr in this case) (accept 24 ml/hr for 1^st 48 hours)
Assess % dehydration and replace over 48 hours using maintenance fluid (unless sodium increases > 150 mmol/L) Formula: Vol = % Dehydration x body weight x 10 (in mls)
Use an inotrope: e.g. adrenaline (other inotropes acceptable)
IV antibiotics within one hour. These can be stopped after 48 hours if cultures negative
Treat hyperkalaemia if still present after treatment of shock (usually K⁺ levels drop as shock treated) o IV CaCl₂
- IV boluses 8.45% NaHCO₃ (Dose in mmol or ml = desired HCO₃ – measured HCO₃ x (weight in kg x 0.6)
- Dextrose/insulin
Urinary catheter to monitor hourly urine output
Consideration of non-infectious causes
Organisation of transfer/retrieval team
Keep the parents up to date

Exact doses of drugs/fluids not expected but reference to need to look up/check dosing carefully in this instance

Additional Examiners‟ Comments:

Most candidates did well in this question. Failure to immediately treat the hypoglycaemia was a fatal error.

Discussion

"Concurrent resuscitation, assessment and treatment" seems to make the redundant distinction between resuscitation and treatment. Some treatments are resuscitative, and resuscitation is a treatment. But that pedantry aside, this college answer is stereotypic for the management of the child with nonspecific shock.

An example approach is offered below:

Assess the need for intubation.
- At this stage, senior assistance from somebody expert in paediatric critical care is required, as the intubation may be difficult.
Administer 100% oxygen.
Establish venous access.
- Give a 20ml/kg bolus, FEAST be damned.
- Inotropes and vasopressors if no longer fluid-responsive
- Parameters guiding resuscitation (eg. lactate, haemodynamic variables, urine output) differ little from adult standards
Sedation and analgesia to support tolerance of invasive therapies
(also decreases demands on the cardiac output)
Electrolyte correction
Maintenance fluid: As per college answer, "add 100 ml of 50% dextrose to 900 ml 0.9% NaCl and infuse this at 2/3 maintenance rate (16 ml/hr in this case) (accept 24 ml/hr for 1^st 48 hours)".
- A urinary catheter will also be required.
No protein in diet until metabolic screen is cleared
- Maintain normoglycaemia with infusion of 10% dextrose of dextrose-rich maintenance fluid
Blood transfusion may not be warranted
Empiric antibiotics if sepsis is suspected, within 1 hour.
- Cultures of blood and urine.
- Consider antivirals if there is suspicion of viral meningitis or encephalitis

For maintenance calculation, the following formula is the gold standard, found in this 1957 paper by Holliday and Segar. A good modern revision was performed by Meyers (2009). In short,

First 10kg: 4ml/kg/hr
Second 10kg: 2ml/kg/hr
All other kgs: 1ml/kg/hr

The reduced 2/3 of the maintenance rate is usually given to critically ill children because of their propensity to secrete ADH, thereby causing water retention. A full maintenance rate is usually given to the well child fasted for theatre.

Isotonic fluids should be used for maintenance, in contrast to the college answer. Wang et al (2013) suggest that they are safer than hypotonic fluids. This contrasts slightly with the college answer. NICE guidelines (Neilson et al, 2015) also recommend isotonic crystalloid for maintenance, and make no mention of the dextrose cocktail which the college recommend ("add 100 ml of 50% dextrose to 900 ml 0.9% NaCl"). The RCH guidelines from Melbourne recommend the routine use of Plasmalyte 148 together with 5% dextrose, without offering any references. The 900/100 mixture describe by the college in this case is in any case nearly isotonic (though fairly hyperosmolar, 550mOsm/L or thereabout)

References

Steiner, Michael J., Darren A. DeWalt, and Julie S. Byerley. "Is this child dehydrated?." Jama 291.22 (2004): 2746-2754.

Levine, Adam C., et al. "Empirically Derived Dehydration Scoring and Decision Tree Models for Children With Diarrhea: Assessment and Internal Validation in a Prospective Cohort Study in Dhaka, Bangladesh." Global Health: Science and Practice 3.3 (2015): 405-418.

Freedman, Stephen B., et al. "Diagnosing clinically significant dehydration in children with acute gastroenteritis using noninvasive methods: a meta-analysis." The Journal of pediatrics 166.4 (2015): 908-916.

Friedman, Jeremy N., et al. "Development of a clinical dehydration scale for use in children between 1 and 36 months of age." The Journal of pediatrics 145.2 (2004): 201-207.

Gorelick, Marc H., Kathy N. Shaw, and Kathleen O. Murphy. "Validity and reliability of clinical signs in the diagnosis of dehydration in children." Pediatrics 99.5 (1997): e6-e6.

Holliday, Malcolm A., and William E. Segar. "The maintenance need for water in parenteral fluid therapy." Pediatrics 19.5 (1957): 823-832.

Meyers, Rachel S. "Pediatric fluid and electrolyte therapy." The Journal of Pediatric Pharmacology and Therapeutics 14.4 (2009): 204-211.

Wang, Jingjing, Erdi Xu, and Yanfeng Xiao. "Isotonic versus hypotonic maintenance IV fluids in hospitalized children: a meta-analysis." Pediatrics (2013): peds-2013.

Neilson, Julie, et al. "Intravenous fluids in children and young people: summary of NICE guidance." BMJ: British Medical Journal (Online) 351 (2015).

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