9.4 Oxygen and Coordination During Compressions

The Compression Phase Is a Different Oxygen World

Early in resuscitation of a term newborn, NRP starts PPV with 21% oxygen (room air) and titrates using pulse oximetry toward age-based target saturations. That restraint reduces unnecessary hyperoxia during milder compromise. Everything changes when the heart rate stays below 60 despite effective ventilation and compressions are started. At that point the infant has profound bradycardia with inadequate cardiac output. Teaching is clear: increase the oxygen concentration to 100% when chest compressions begin.

This is one of the highest-yield “switch” facts on the exam:

Do not “keep whatever was set during initial PPV” once thumbs are on the chest. Do not drop to room air mid-compressions hoping to be gentle. Profound circulatory failure is not the time for low FiO₂ experiments.

Why 100% during compressions

Cardiac output is critically low; tissue and myocardial oxygen delivery depend on maximizing arterial oxygen content of the small volume of blood that is being circulated. Once heart rate recovers and pulse oximetry is reliable, wean oxygen to avoid prolonged hyperoxia—but start compressions on 100%.

Coordination: Compressions and Breaths Must Alternate

Oxygen concentration alone does not save the infant if breaths are mistimed. Coordination rules during newborn CPR:

1. Use the 3:1 ratio and spoken cadence (“one-and-two-and-three-and-breathe”).
2. Deliver the ventilation during the pause after the third compression.
3. Do not compress and inflate simultaneously as the default pattern.
4. Ensure an advanced airway (ETT or LMA) when possible so the ventilator can deliver reliable tidal volumes on the breath beat.
5. Watch for chest rise on the breath only—if rise is gone, fix the airway rather than only “push harder.”

Simultaneous compression on a chest that is being bagged can reduce effective ventilation and is not the coordinated pattern NRP wants you to demonstrate.

Role of the compressor as metronome

The person doing compressions usually owns the count. Loud, steady counting keeps two brains synchronized under stress. Soft mumbling leads to free-style bagging. If the ventilator cannot hear the count, quality collapses into simultaneous or random actions.

Role of the ventilator

On “breathe,” deliver a single inflation with appropriate pressure—not a prolonged multi-second hold that delays return to compressions, and not a series of extra breaths between every compression. One breath per cycle, then back to three compressions.

Reassessment Rhythm: About Every 60 Seconds

After coordinated compressions and ventilation are underway, continue for approximately 60 seconds before pausing briefly to reassess the heart rate. Preferred tool: ECG monitor for rapid, continuous rate display, confirmed clinically when needed with auscultation or pulse check as appropriate to the situation.

What “brief” means

The pause is for decision-making, not a meeting. Look at the ECG number, announce it (“Heart rate 80—stop compressions, continue ventilation” or “Heart rate 40—resume compressions, draw epinephrine”), and restart immediately if still <60.

What not to do

• Do not interrupt every 10 seconds for pulse checks.
• Do not run five minutes without reassessment.
• Do not rely only on color or a single delayed SpO₂ number while ignoring ECG.
• Do not stop compressions for documentation of Apgar scores mid-crisis.

Pulse oximeters may lag or fail in low-perfusion states; ECG is preferred for heart rate when resuscitation is intensive.

When to Stop Compressions

Stop chest compressions when the heart rate is ≥60 bpm.

Then:

• Continue high-quality ventilation as needed (the infant may still be apneic or hypoventilating).
• Wean oxygen from 100% toward target preductal saturations as HR and perfusion improve and oximetry becomes trustworthy.
• Support temperature, assess for need for ongoing PPV or CPAP, and prepare for post-resuscitation care.
• Do not stop ventilating merely because compressions stopped; many infants still need PPV after the heart rate climbs above 60.

If HR is 55 after a reassessment, resume compressions—do not “wait and see” without circulatory support when still below threshold.

When Heart Rate Stays Below 60: Prepare Epinephrine

If after coordinated ventilation and compressions the heart rate remains <60, the algorithm moves toward epinephrine while CPR continues. Key coordination points for this section (details of dosing live in the medications chapter):

• Do not stop quality 3:1 CPR to focus only on drug prep.
• Establish emergency vascular access—umbilical venous catheter preferred; intraosseous as alternative when UVC is not feasible.
• Epinephrine is given for persistent HR <60 despite adequate ventilation and compressions, not as a first step for mild bradycardia.
• Assign a dedicated person to prepare the dose so the compressor and ventilator stay on task.

The cognitive error to avoid: freezing compressions for a long sterile umbilical procedure without anyone covering CPR. Either continue compressions with adjusted technique (two-finger if needed) or very brief, planned interruptions with immediate return to the cadence.

Putting Oxygen, Coordination, and Reassessment Together

A clean sequence once the compression indication is met:

1. Call it out: “Heart rate still under 60 after effective PPV—starting compressions.”
2. Oxygen to 100%.
3. Confirm advanced airway (ETT/LMA) if not already secured.
4. Assign roles: compressor (count), ventilator (breath on “breathe”), access/meds, leader/timer.
5. Run ~60 seconds of 3:1 with full depth, recoil, and no simultaneous breath-compression.
6. Brief HR reassessment on ECG.
7. Branch:
   • HR ≥60 → stop compressions, continue ventilation, wean O₂ as able.
   • HR <60 → resume compressions, ensure access, give epinephrine per protocol, reassess again after coordinated CPR intervals.

Team Communication Scripts That Match NRP

Correct:
“Increasing to one hundred percent oxygen.”
“Compressions—one-and-two-and-three-and-breathe.”
“Sixty seconds—check heart rate… heart rate seventy—stop compressions, continue PPV.”
“Heart rate still forty—resume compressions; epinephrine ready for UVC.”

Incorrect:
“Leave oxygen at twenty-one percent during compressions.”
“Bag whenever you can while I keep pushing.”
“Let’s check the heart rate every five compressions.”
“Heart rate sixty-five—keep compressing another two minutes just in case.”

Exam Traps Specific to This Phase

1. Oxygen trap: Choosing to continue room air or 40% during compressions.
2. Simultaneous trap: Preferring continuous compressions with asynchronous bagging as the NRP standard answer.
3. Reassessment trap: Checking HR every 10 seconds or waiting 5 minutes.
4. Stop-compressions trap: Stopping only when HR >100, or never stopping at 60. The threshold to discontinue compressions is ≥60, not 100. (HR <100 still needs ventilation support, but not necessarily compressions.)
5. Medication trap: Giving epinephrine before effective ventilation and compressions are established.
6. Weaning trap: Leaving the infant on 100% forever after recovery without SpO₂-guided adjustment.

Scenario Synthesis

Scenario A. Compressions just started; blender still at 21%. Correct action: raise to 100% immediately.

Scenario B. After 60 seconds of coordinated CPR, ECG shows HR 72. Correct action: stop compressions, continue PPV, begin weaning oxygen as saturations allow.

Scenario C. After 60 seconds, HR 38, advanced airway confirmed, chest rising on breaths. Correct action: continue 3:1 CPR, epinephrine via emergency UVC/IO, reassess after further coordinated cycles.

Scenario D. Team bags during every compression. Correct coaching: pause thumbs for the single breath on “breathe,” then resume three compressions.

Why This Section Closes the Compression Chapter

Indication tells you whether to start. Ratio and technique tell you how to move blood and air. Oxygen and coordination tell you how to run the minute-to-minute system: maximize oxygen content, synchronize two rescuers, reassess on a disciplined schedule, stop at the right threshold, and escalate to medications without abandoning CPR quality. Master these links and the chest-compression domain becomes a coherent algorithm branch rather than a pile of disconnected facts.

One-page recovery checklist after compressions stop

• Ventilation still effective?
• FiO₂ weaning with preductal SpO₂?
• Temperature and glucose planning?
• Family update and team debrief later?
• Documentation of times: PPV start, compression start/stop, epi doses?

Those post-ROSC tasks belong to later chapters, but the compression phase ends cleanly only when HR ≥60 and ventilation continues with intentional oxygen management.