Anesthesiology APPLIED Exam › Pediatric and neonatal

The child with an upper respiratory infection

T1Pediatric and neonatal·957 words · ~5 min read·v0.1DRAFT

Why examiners ask this

Every pediatric stem can carry a runny nose, and the examiner uses it to test judgment under uncertainty: there is no rule that settles the question, so I have to weigh risk factors, the urgency of the surgery and the airway plan, then commit. It also sets up the two complications the examiner most likes to inject in a child, laryngospasm and bronchospasm, and it tests adaptability when the parent pushes back on a cancellation.

The 60-second answer

A child with a current or recent upper respiratory infection has airway hyperreactivity that lasts 2–6 weeks, and the question is whether the added risk of laryngospasm, bronchospasm and desaturation outweighs the cost of delaying surgery. I proceed with a child who has clear rhinorrhea, no fever, a normal chest and a parent who says this is baseline, especially for a short case without an endotracheal tube. I postpone for 2–4 weeks when there is fever above 38 °C, purulent secretions, a productive cough, wheeze or crackles, lethargy, or a child under 1 year with a history of prematurity or reactive airway disease, and when the surgery itself involves the airway. When I proceed, I give albuterol 30 minutes before induction, use sevoflurane or propofol with a laryngeal mask where possible, avoid desflurane, keep the plane deep for airway manipulation, and extubate either deep or fully awake, never in between.

Decision points and the "why"

Proceed versus postpone — the risk of a serious adverse event is small in absolute terms but 2–10 times higher with an active infection, and the hyperreactivity persists for 6 weeks, so a 2-week delay buys little unless the child is clearly sick. I postpone for the sick child and the airway surgery; I proceed for the ambulatory, afebrile child with a laryngeal mask. A history of parental smoking, prematurity or asthma moves me toward delay.
Laryngeal mask over endotracheal tube — the tube triggers more laryngospasm and bronchospasm in an irritable airway; a laryngeal mask carries about half the risk. I use a tube when the surgery demands it or the child is at aspiration risk.
Albuterol pretreatment — 2.5 mg nebulized or 4 puffs by spacer within the hour reduces perioperative respiratory adverse events in children with recent infections; it costs nothing.
Sevoflurane, not desflurane — desflurane increases airway resistance in a reactive airway and causes coughing and laryngospasm; propofol blunts airway reflexes and is my induction choice when an intravenous line is already in.
Depth for airway manipulation — laryngospasm follows stimulation under light anesthesia. I place or remove the device at a deep plane or with the child fully awake, and I add lidocaine 1–1.5 mg/kg IV before extubation when I expect coughing.
Discharge planning — a child who desaturated or wheezed stays until the saturation is at baseline on room air; I warn the parents that a cough and low-grade fever for a few days are expected.

The complication they will inject

At emergence the child develops stridor, then silence, with paradoxical chest movement and a falling saturation. I call it laryngospasm, remove the stimulus, apply continuous positive airway pressure with 100% oxygen and a tight mask, and perform a jaw thrust with pressure at the laryngospasm notch. If the saturation keeps falling I give propofol 1 mg/kg, and if there is no intravenous line or the spasm persists, succinylcholine 1–2 mg/kg IV or 4 mg/kg IM with atropine 20 mcg/kg, then ventilate and reintubate if needed. I watch for negative-pressure pulmonary edema afterward: pink frothy sputum and hypoxemia that need positive pressure and time. The alternative inject is wheeze with a rising airway pressure after intubation, where I deepen the anesthetic, give albuterol through the tube, and exclude a mainstem intubation or a kinked tube before I call it bronchospasm.

Pitfalls that cost points

Answering "I would cancel" or "I would proceed" without the risk factors that drove the choice.
Saying the safe interval is 2 weeks and stopping there; the examiner wants to hear that hyperreactivity lasts up to 6 weeks and that the delay is a trade-off.
Choosing an endotracheal tube by reflex for a case a laryngeal mask would serve.
Extubating at a light plane and then describing laryngospasm as unexpected.
Forgetting that the parent needs an explanation: a cancellation is a communication task.

Rapid-why

Q: Why does a viral infection cause bronchospasm weeks later? A: Epithelial damage exposes irritant receptors and the virus increases vagal sensitivity and reduces neutral endopeptidase, so bronchoconstriction persists after the symptoms clear.

Q: Which symptoms predict adverse events most strongly? A: Moist cough, purulent secretions, wheeze, fever and lethargy; clear rhinorrhea alone adds little.

Q: Why does laryngospasm cause negative-pressure pulmonary edema? A: Inspiring against a closed glottis generates very negative intrathoracic pressure, raising capillary transmural pressure and pulling fluid into the alveoli.

Q: When is succinylcholine contraindicated here? A: With a known myopathy, hyperkalemia or malignant hyperthermia susceptibility; otherwise it remains the drug for life-threatening laryngospasm in a child.

Numbers to know

Item	Value
Airway hyperreactivity after URI	Up to 6 weeks
Usual postponement	2–4 weeks for a sick child
Albuterol pretreatment	2.5 mg nebulized or 4 puffs 30 min before induction
Propofol for laryngospasm	0.5–1 mg/kg IV
Succinylcholine for laryngospasm	1–2 mg/kg IV; 4 mg/kg IM with atropine 20 mcg/kg
Lidocaine before extubation	1–1.5 mg/kg IV

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