Paeds SAQs · infectious-diseases
Paediatric sepsis: diagnosis, antimicrobial treatment and source control — formative SAQs
Two MedVellum formative short-answer questions on paediatric sepsis, covering Phoenix-criteria recognition, the first-hour bundle (cultures, empiric antibiotic within one hour, judicious fluids, early vasoactives), source control, reassessment and escalation. The marks and timing support transparent self-assessment; they are not an official board format or pass standard.
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Target exams
SAQ 1 — A school-age child with septic shock
Question 1 — 10 formative marks; suggested time 15 minutes [1]
A previously well 7-year-old boy presents with two days of fever and cough. He is now less interactive, mottled from the knees down, and has cool peripheries with a capillary refill of 4 seconds. His heart rate is 150, blood pressure 92/50, respiratory rate 36, and he is oliguric. A venous lactate is 4.2 mmol/L. [1] [12]
- Classify his state using the Phoenix criteria and define the syndrome. (2 marks)
- Outline your first-hour bundle, including the antibiotic timing target and fluid strategy. (4 marks)
- Describe your reassessment loop and the triggers to stop fluids and start vasoactives. (2 marks)
- Justify how the FEAST and Fluids in Shock evidence shapes a cautious fluid approach. (2 marks)
Full-credit answer — SAQ 1
Reveal full-credit answer for SAQ 1
1. Phoenix classification
This child has suspected infection (fever, cough, probable pneumonia) with life-threatening organ dysfunction. His circulatory failure — impaired perfusion, oliguria and a raised lactate — gives him at least one Phoenix cardiovascular point, so he meets both sepsis and septic shock. A normal-range blood pressure does not exclude shock; children are hypotensive late because they compensate with tachycardia and vasoconstriction. [1] [2]
2. First-hour bundle
I would assign a team leader, call the senior paediatric and critical-care teams, attach monitoring and estimate his weight. I would draw two blood cultures from separate sites and a lactate before antibiotics only because it will not delay the first dose; I would add urine and, if stable, cerebrospinal fluid cultures when safe. I would give the first broad-spectrum, weight-based antibiotic within one hour of recognising sepsis — a third-generation cephalosporin, with vancomycin if resistant organisms are possible per local guidance. [3]
For fluids I would give a 10 mL/kg crystalloid aliquot and reassess immediately, repeating only if shock persists and he remains fluid-responsive, and stopping at a locally agreed ceiling rather than chasing a target. This is cold shock, so if he remains poorly perfused I would start adrenaline (epinephrine) as the first vasoactive, titrated to perfusion and age-appropriate mean arterial pressure. [3] [12]
3. Reassessment loop and escalation triggers
After every intervention I would reassess mental state, perfusion, capillary refill, pulse quality, lactate trend, liver size, breath sounds and urine output. I would stop fluids and start or escalate vasoactives if he develops new hepatomegaly, a gallop rhythm, bilateral crackles, a rising lactate despite fluids, or persistent shock with signs of fluid overload. I would involve PICU early and request retrieval before local capability is exceeded. [3] [11]
4. Evidence for a cautious fluid approach
The FEAST trial showed that fluid boluses increased mortality in African children with severe infection, although that population lacked intensive-care rescue; the Fluids in Shock pilot then showed that a restricted-bolus strategy is feasible. Together these support aliquots with reassessment and a ceiling, applied with judgement to the resources that can rescue the child, rather than an uncritical drive to a fixed volume. [8] [9]
Marking grid — SAQ 1
| Domain | Full-credit requirements | Marks |
|---|---|---|
| Recognition & classification | Correct Phoenix classification of septic shock; explains why blood pressure is late | 2 |
| First-hour bundle | Cultures-if-no-delay, antibiotic within 1 hour, fluid aliquots, adrenaline for cold shock | 4 |
| Reassessment & escalation | Loop checks; explicit triggers to stop fluids and start vasoactives | 2 |
| Evidence base | Accurate, setting-aware account of FEAST and Fluids in Shock | 2 |
Common pitfalls — SAQ 1
- Treating blood pressure as the threshold for shock, or continuing fluids past the ceiling.
- Delaying antibiotics for imaging or an unsafe lumbar puncture.
- Forgetting source control (chest imaging, empyema drainage).
- Quoting FEAST uncritically without noting the population and rescue-resource limits.
SAQ 2 — Source control, reassessment and equity in a regional setting
Question 2 — 10 formative marks; suggested time 15 minutes [11]
A 5-year-old girl with a long-term central venous catheter for short-bowel syndrome presents to a regional hospital with fever and rigors. She is tachycardic and intermittently confused. Her mother says she is not herself. The hospital can provide initial paediatric stabilisation but cannot sustain invasive ventilation or vasoactive support, and retrieval will take several hours. [11] [12] [13]
- Frame the problem and identify the most likely source and source-control priority. (2 marks)
- Outline the first-hour bundle tailored to a central-line infection in a regional setting. (4 marks)
- Describe the reassessment, retrieval and handover plan. (2 marks)
- Explain how equity and special-population factors apply to her care. (2 marks)
Full-credit answer — SAQ 2
Reveal full-credit answer for SAQ 2
1. Problem framing and source control
This is a technology-dependent child with suspected central-line-associated bloodstream infection causing sepsis with possible early shock (tachycardia, confusion). The source-control priority is removal of the infected central line once alternative access is established, alongside broad empiric cover that includes coagulase-negative staphylococci and resistant Gram-negatives per local protocol. I would treat her as septic until proven otherwise and use her mother's report of a change from baseline as a credible cue. [11] [12]
2. First-hour bundle in a regional setting
I would call the senior clinician and retrieval early, assign a leader, attach monitoring and estimate her weight. I would draw blood cultures — including from the central line and a peripheral site — before antibiotics only if it does not delay them. I would give a broad-spectrum, weight-based antibiotic within one hour that covers line organisms, adding antistaphylococcal and anti-pseudomonal agents as local guidance dictates. [3]
I would give a 10 mL/kg crystalloid aliquot for shock and reassess, stopping at a ceiling and watching for fluid intolerance. Because this hospital cannot sustain vasoactives, I would agree a monitored backup plan with retrieval: who gives what, the next sign of failure, and the contingency if transfer is delayed. I would arrange urgent line removal or exchange with appropriate expertise. [11] [12]
3. Reassessment, retrieval and handover
I would reassess after every intervention and document the trend. I would call retrieval before local capability is exceeded, giving her age and weight, baseline, Phoenix score and shock status, the devices and emergency plan, timed interventions and responses, the working diagnosis (line infection), and local limits including staffing and transport time. Structured handover would carry the diagnosis, pending cultures, the antimicrobial plan and the specific deterioration plan. [11] [13]
4. Equity and special-population factors
Children with complex chronic conditions and technology dependence, and those in regional or disadvantaged settings, are recognised and treated for sepsis later than their peers — the Child Opportunity Index cohort showed exactly this. I would weigh distance, escort skill and retrieval delay in the plan, communicate clearly with her mother, and ensure the safety net and follow-up are practical and owned. Source control and timely antimicrobials matter most where rescue resources are limited. [13]
Marking grid — SAQ 2
| Domain | Full-credit requirements | Marks |
|---|---|---|
| Problem & source control | Line infection; line removal as source-control priority | 2 |
| Regional first-hour bundle | Paired cultures, broad cover incl. line organisms, fluid aliquots, backup plan | 4 |
| Reassessment & handover | Loop checks; early retrieval; structured handover content | 2 |
| Equity & special populations | Accurate application of opportunity index, distance and complex-child factors | 2 |
Common pitfalls — SAQ 2
- Treating the line as untouchable and forgetting that removal is definitive therapy.
- Giving fluids without a ceiling or backup plan in a setting that cannot rescue.
- A vague handover that omits the working diagnosis, pending cultures or the deterioration plan.
- Ignoring the equity dimension of regional and complex-child sepsis.
References
- [1]Sanchez-Pinto, L Nelson; Bennett, Todd D; DeWitt, Peter E Development and Validation of the Phoenix Criteria for Pediatric Sepsis and Septic Shock. JAMA, 2024.PMID 38245897
- [2]Schlapbach, Luregn J; Watson, R Scott; Sorce, Lynn R International Consensus Criteria for Pediatric Sepsis and Septic Shock. JAMA, 2024.PMID 38245889
- [3]Weiss, Scott L; Peters, Mark J; Oczkowski, Stephen J W Surviving Sepsis Campaign International Guidelines for the Management of Sepsis and Septic Shock in Children 2026. Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies, 2026.PMID 41869844
- [8]Maitland, Kathryn; Kiguli, Sarah; Opoka, Robert O Mortality after fluid bolus in African children with severe infection. The New England journal of medicine, 2011.PMID 21615299
- [9]Inwald, David P; Canter, Robert; Woolfall, Kerry Restricted fluid bolus volume in early septic shock: results of the Fluids in Shock pilot trial. Archives of disease in childhood, 2019.PMID 30087153
- [11]Paul, Richard; Niedner, Matthew; Riggs, Roberta Bundled Care to Reduce Sepsis Mortality: The Improving Pediatric Sepsis Outcomes (IPSO) Collaborative. Pediatrics, 2023.PMID 37435672
- [12]Bjorklund, Ashley; Resch, Jacob; Slusher, Tina Pediatric Shock Review. Pediatrics in review, 2023.PMID 37777656
- [13]Rutman, Laila; Richardson, Tyler; Auletta, Joseph Association between Child Opportunity Index and paediatric sepsis recognition and treatment in a large quality improvement collaborative: a retrospective cohort study. BMJ quality & safety, 2026.PMID 40345682