7.3 Confirming Endotracheal Tube Placement

Confirmation Is Not Optional

Passing a tube “between what looked like cords” is only the beginning. Until you prove air is entering both lungs and improving the infant’s physiology, you must treat placement as unconfirmed. Wrong-tube disasters in the delivery room almost always share one feature: the team assumed success because laryngoscopy felt good, then watched the heart rate fall while ventilating the stomach or one lung.

NRP confirmation is a bundle of findings. No single sign is perfect. The goal is rapid, simultaneous assessment immediately after the tube is thought to be in the trachea—then continuous re-checking after securing and during compressions.

Primary Physiologic Sign: Rising Heart Rate

Among all indicators, a rising heart rate with ventilation is the best sign that effective gas exchange is beginning. Bradycardia in the newly born is driven largely by hypoxia. When the lungs inflate and oxygen delivery improves, heart rate typically climbs within seconds to tens of seconds.

How to use heart rate at the bedside

• Call out the number before and after placement: “HR 55… tube in… HR 80 and rising.”
• Prefer ECG monitoring during advanced resuscitation for continuous display; confirm with auscultation when needed.
• If the tube is “in” but the HR stays 40–50 with no chest movement, do not celebrate—assume failure of effective ventilation until proven otherwise.

Heart rate improvement does not by itself prove the tip is perfectly mid-tracheal (mainstem intubation can still raise HR if one lung works), but failure of HR to improve with supposed tracheal ventilation is a loud alarm for esophageal placement, disconnected circuit, occluded tube, or absent pulmonary blood flow.

Exhaled CO₂ Detection

Colorimetric CO₂ detectors (or capnography when available) are placed between the tube and the ventilation device. With tracheal placement and adequate pulmonary blood flow, exhaled CO₂ typically produces a color change (commonly purple → yellow on many devices—know your product’s legend).

Strengths

• Fast, visible to the whole team
• Strong support for tracheal placement when positive in a resuscitated newborn
• Useful during compressions as part of ongoing airway assessment

Critical limitations (exam favorite)

CO₂ detection depends on CO₂ delivery to the lungs, which requires pulmonary blood flow. In profound bradycardia or cardiac arrest with very low cardiac output, a correctly placed tracheal tube may show little or no color change. Conversely, contaminants or device failure can confuse interpretation.

Therefore:

• Positive CO₂ + rising HR + bilateral signs → strong confirmation.
• Negative CO₂ + no HR improvement → treat as esophageal intubation or ineffective ventilation until proven otherwise: remove tube, mask/LMA ventilate, retry.
• Negative CO₂ but you are uncertain in profound low output → integrate all signs; if doubt, remove and ventilate. Do not cling to a silent detector while the infant deteriorates.

Never use CO₂ color alone as the only thought process, and never ignore a persistently negative detector when HR is not rising.

Additional Clinical Signs

Bilateral breath sounds

Auscultate both axillae (not only the anterior chest, which transmits sound easily). Equal breath sounds support mid-tracheal position. Sounds louder on the right with quiet left suggest right mainstem intubation—pull the tube back slightly and reassess. Gastric sounds with a stethoscope over the stomach during ventilation suggest esophageal placement.

Symmetric chest rise

Look for gentle, equal expansion. Unilateral rise, asymmetric chest wall motion, or a rapidly expanding abdomen points to mainstem or esophageal problems. In very preterm infants chest movement can be subtle—combine with HR and CO₂.

Mist (condensation) in the tube

Fogging in the tube lumen can appear with tracheal placement but is unreliable alone. Mist can be misleading; never accept mist as sole confirmation.

Improving color and SpO₂

These often lag heart-rate improvement. They support success over minutes but are slower decision tools than HR and CO₂ in the first seconds after placement.

Direct visualization

Seeing the tube pass through the cords is helpful but still requires post-placement confirmation—tubes can dislodge during securing.

Classic Trap 1: Esophageal Intubation

Clues:

• No CO₂ color change (when output should produce CO₂)
• Heart rate not rising
• No chest rise; abdomen distending
• Breath sounds better over the stomach than the axillae
• Cyanosis deepening despite “ventilation”

Action: Remove the tube. Ventilate with face mask (MR SOPA as needed) or place a laryngeal mask. Re-oxygenate, then reattempt intubation with a time limit—or continue with LMA if ETT remains unsuccessful.

Leaving an esophageal tube in place while “troubleshooting the detector” is a high-risk error.

Classic Trap 2: Right Mainstem Intubation

The right main bronchus is more vertical; over-insertion preferentially ventilates the right lung.

Clues:

• Unequal breath sounds (↓ left)
• Asymmetric chest rise
• Possible CO₂ still present and HR may still improve (because one lung works)—so CO₂ alone will not catch this
• Risk of left-sided atelectasis and right-sided overdistention/pneumothorax with high pressures

Action: While ventilating, carefully withdraw the tube a short distance, re-secure at the new tip-to-gum mark, and recheck bilaterally. Recheck after every major position change.

The “If in Doubt, Take It Out” Rule

NRP culture prioritizes effective ventilation over pride in a difficult laryngoscopy. If the team cannot agree the tube is tracheal and effective:

1. Remove the endotracheal tube.
2. Ventilate with face mask or LMA.
3. Restore heart rate and chest rise.
4. Plan the next attempt (better positioning, suction, different blade/tube, more experienced operator) or accept LMA as the working advanced airway.

This rule appears in many exam stems as “persistent absence of CO₂ with no HR improvement”—the correct response is not to give epinephrine down a dubious tube first; it is to fix ventilation by removing the bad airway.

Confirmation Sequence You Can Recite

Immediately after insertion:

1. Connect CO₂ detector and begin PPV.
2. Watch for color change and chest rise.
3. Check heart rate trajectory.
4. Auscultate both axillae and listen over the stomach if concerned.
5. Note tip-to-gum depth; secure only after initial confirmation.
6. Reconfirm after securing and any movement.
7. If doubt → out, mask/LMA, restart.

Special Contexts

During chest compressions

An advanced airway allows pause-free compression cadence with interposed ventilations per NRP coordination. Continue to monitor CO₂ and HR; a sudden loss of CO₂ after previous confirmation may mean dislodgement.

Before surfactant

Confirm placement with the full bundle before instilling surfactant so drug is not delivered into the esophagus or a single lung.

Extremely low cardiac output

Rely more heavily on visualization quality, chest rise, and the overall clinical picture; remember CO₂ may lag or stay negative until circulation improves. Still do not accept a tube that produces no chest rise.

Exam Traps Summary

Closing Clinical Picture

Confirmation is a team sport. One person watches the detector, one watches the chest, one calls the heart rate, and anyone can say “I don’t think this tube is good.” That sentence should trigger action—not defensiveness. On the NRP exam and in the delivery room, a removed questionable tube plus restored mask ventilation is always better than a politely ignored esophageal intubation.