Undifferentiated shock (peds)
This page is for pediatric patients. For adult patients, see: undifferentiated shock.
Background
Important physiologic differences between pediatric and adult patients
Intravascular volume
- Newborns: larger total body water compared to adults (75% vs. 60%) with the majority of it being in the extracellular fluid (ECF) (~40% vs. 25%)
- Percentage of ECF decreases throughout childhood
- Large surface area to weight ratio --> younger kids may have more fluid losses from ECF and intravascular space with short illness/environmental exposure decreased preload
- May present profoundly volume depleted and need more aggressive volume repletion
Cardiovascular
- Infants have immature myocardial calcium regulation system, difficulty storing/releasing calcium highly dependent on extracellular calcium for contractility
- Check iCal, replete calcium earlier, do NOT give CCBs to infants with tachydysrhythmias
- Stiffer, less compliant myocardium in infants-->increasing heart rate is main compensatory means for increasing BP
- BUT higher resting heart rate--> less room to go up (e.g. adult with resting heart rate of 60 can double to 120 but a neonate doubling resting heart rate of 120 to 240 is not sustainable)
- Heavily rely on vasoconstriction, which can further decrease cardiac output
- Less beta-adrenergic receptors/sympathetic innervations + more dominant parasympathetics --> exaggerated vagal response
- Hypotension is a ‘’’late’’’ finding in shock!
Clinical Features
- Signs/symptoms of underlying pathology
Cold shock
- More common in children than in adults
- Poor cardiac output due to decreased stroke volume--> tachycardia to compensate
- Poor peripheral perfusion, increased SVR (vasoconstriction) to compensate-->
- Skin cold to touch
- Diminished pulses
- Mottled skin
- Cap refill >2s
- Narrow pulse pressure, eventually hypotension
- Signs and symptoms of end organ damage as blood shunted to vital organs
- AMS, tachypnea, nausea/vomiting, AKI, lactic acidosis
Warm shock
- Hyperdynamic state, with vasodilation and low SVR
- Results in end organ damage due to shunting of blood away from vital organs to periphery
- Findings thus include:
- Tachycardia
- Wide pulse pressure
- Bounding peripheral pulses
- Brisk cap refill
Shock index
- Shock Index Pediatric-Adjusted (SIPA)- see https://www.mdcalc.com/shock-index-pediatric-age-adjusted-sipa
- Useful in identifying shock in trauma patients
Differential Diagnosis
- Hypovolemia
- More common and more profound in peds
- hemorrhage,
dehydration (from nausea/vomiting, insensible losses due to heat illness_)
- Cardiogenic
- Obstructive
- Distributive
- Neurogenic shock
Sick Neonate
THE MISFITS [1]
- Trauma
- Heart
- Congenital heart disease
- Hypovolemia
- Endocrine
- Metabolic
- Sodium
- Calcium
- Glucose
- Inborn errors of metabolism
- Seizure
- Formula / feeding problems
- Intestinal Disasters
- Toxin
- Sepsis
Evaluation
Management
- Rapid IV access
- IO if unable to obtain in <1min
- Aggressive IVF
- Remember hypovolemia may be more profound in peds
- 40-60mL/kg NS or lactated ringers rapid bolus (e.g push-pull)
- Vasopressors if remains hypotensive OR with poor perfusion (e.g. cool, poor cap refill) after volume resuscitation
- Cold shock: epinephrine 0.05mcg/kg/min starting dose
- Can be safely given through good peripheral IV [2]
- Warm shock: norepinephrine 0.05mcg/kg/min to start
- Cold shock: epinephrine 0.05mcg/kg/min starting dose
- Empiric antibiotics for sepsis
- Neonatal: Ampicillin 50mg/kg q8h + gentamicin 2.5mg/kg q24h + acyclovir
- Peds: *Extended-spectrum penicillin (e.g. piperacillin-tazobactam) ± aminoglycoside ± vancomycin OR3rd or 4th generation cephalosporin ± aminoglycoside ± vancomycin OR Carbapenem ± aminoglycoside ± vancomycin
- Consider corticosteroids if volume non-responsive
- Treat underlying condition!
- Treat hypoglycemia
- Treat hypocalcemia, consider giving empiric calcium as inotrope
- If suspect ductal-dependant congenital heart disease:
- PGE1 0.1mcg/kg/min IV/IO
- NS 10cc/kg
- Dobutamine
Vasopressors
Pressor | Initial Dose | Max Dose | Cardiac Effect | BP Effect | Arrhythmias | Special Notes |
---|---|---|---|---|---|---|
Dobutamine | 3-5 mcg/kg/min | 5-15 mcg/kg/min (as high as 200) [3] | Strong ß1 agonist +inotrope +chronotrope, Weak ß2 agonist +weak vasodilatation ) | alpha effect minimal | HR variable effects. | indicated in decompensated systolic HF, Debut Research 1979[4] Isoproterenol has most Β2 vasodilatory and Β1 HR effects |
Dopamine | 2 mcg/kg/min | 20-50 mcg/kg/min | β1 and NorEpi release | α effects if > 20mcg/kg/min | Arrhythmogenic from β1 effects | More adverse events when used in shock compared to Norepi[5] |
Epinepherine | 0.1-1 mcg/kg/min | + inotropy, + chronotropy | ||||
Norepinephrine | 0.2 mcg/kg/min | 0.2-1.3 mcg/kg/min (5mcg/kg/min) [6] | mild β1 direct effect | β1 and strong α1,2 effects | Less arrhythmias than Dopamine[5] | First line for sepsis. Increases MAP with vasoconstriction, increases coronary perfusion pressure, little β2 effects. |
Milrinone | 50 mcg/kg x 10 min | 0.375-75 mcg/kg/min | Direct influx of Ca2+ channels | Smooth muscle vasodilator | PDE Inhibitor which increases Ca2+ uptake by sarcolemma. No venodilatory activity | |
Phenylephrine | 100-180 mcg/min then 40-60 mcg/min | 0.4-9 mcg/kg/min | Alpha agonist | Long half life | ||
Vasopressin | Fixed Dose | 0.01 to 0.04 U/min | unknown | increases via ADH peptide | should not be titrated due to ischemic effects | |
Methylene blue[7] | IV bolus 2 mg/kg over 15 min | 1-2 mg/kg/hour | Possible increased inotropy, cardiac use of ATP | Inhibits NO mediated peripheral vasodilation | Don't use in G6PD deficiency, ARDS, pulmonary hypertension |
Medication | IV Dose (mcg/kg/min) | Concentration |
Norepinephrine (Levophed) | 0.1-2 mcg/kg/min | 8mg in 500mL D5W |
Dopamine | 2-20 mcg/kg/min | 400mg in 250 D5W |
Dobutamine | 2-20 mcg/kg/min | 250mg in 250 mg D5W |
Epinephrine | 0.1-1 mcg/kg/min | 1mg in 250 D5W |
Causes of non-response to vasopressors[8]
- Acidosis
- Dx: Blood gas, BMP
- Tx: treat underlying cause, consider bicarbonate gtt
- Hypothyroidism
- Dx: Clinical, TSH
- Tx: levothyroxine
- Anaphylaxis
- Dx: History
- Tx: Epinephrine, methylene blue, ECMO
- Adrenal insufficiency
- Dx: Clinical, cortisol level, hyperkalemia + hyponatremia
- Tx: Hydrocortisone 100-200mg
- Hypocalcemia
- Dx: ionized calcium, prolonged QTc
- Tx: Calcium chloride or calcium gluconate
- Occult bleeding
- Dx: Clinical (consider GI bleed and retroperitoneal hematoma)
- Tx: Transfusion, treat coagulopathy, surgery/IR interventions
- Toxicologic
- Dx: Clinical (consider beta blocker toxicity, calcium channel blocker toxicity, TCA overdose, etc)
- Tx: Depends on etiology (glucagon, hyperinsulin euglycemia therapy, sodium bicarbonate, ECMO, etc)
- 2nd cause of shock
- Dx: Clinical, consider RUSH exam
- Tx: Address underlying cause
Disposition
- NICU/PICU
See Also
External Links
References
https://rebelem.com/approach-to-the-critically-ill-child-shock/ https://pedemmorsels.com/epinephrine-for-shock/ https://www.chop.edu/clinical-pathway/sepsis-emergent-care-clinical-pathway
- ↑ Brousseau T, Sharieff GQ. Newborn emergencies: the first 30 days of life. Pediatr Clin North Am. 2006 Feb;53(1):69-84, vi.
- ↑ Ramaswamy KN1, Singhi S, Jayashree M, Bansal A, Nallasamy K. Double-Blind Randomized Clinical Trial Comparing Dopamine and Epinephrine in Pediatric Fluid-Refractory Hypotensive Septic Shock. Pediatr Crit Care Med. 2016 Sep 23.
- ↑ https://www.ncbi.nlm.nih.gov/pubmed/8449087
- ↑ Edmund H. Sonnenblick, M.D., William H. Frishman, M.D., and Thierry H. LeJemtel, M.D. Dobutamine: A New Synthetic Cardioactive Sympathetic Amine
- ↑ 5.0 5.1 De Backer Daniel et al. Comparison of Dopamine and Norepinephrine in the Treatment of Shock. NEJM 363(9). 779-789
- ↑ https://www.ncbi.nlm.nih.gov/pubmed/15542956
- ↑ Pasin L et al. Methylene blue as a vasopressor: a meta-analysis of randomised trials. Crit Care Resusc. 2013 Mar;15(1):42-8.
- ↑ Anand Swaminathan, "Occult Causes of Non-Response to Vasopressors", REBEL EM blog, July 13, 2017. Available at: https://rebelem.com/occult-causes-of-non-response-to-vasopressors/.