We are often drawn to new techniques and methods. While we may become enamored with exotic management strategies (ex, ECMO in the ED, Delayed Sequence Intubation), focusing on the basics is vitally important to the successful management of even the most critically ill. Often it is simple strategies that are most effective – like methods to Avoid Oxygen Desaturations or to Optimize Chest Compressions. We must, however, recognize our own limitations. The mere act of accurately palpating a pulse (something that should be relatively simple) is extremely challenging and we cannot afford to be inaccurate. This is particularly true when involved in the resuscitation of a newborn! Thanks to Dr. Elise Alves Graber (one of the stellar PEM fellows at CMC), I was reminded of this. Let’s quickly review something simple, but very critical – Newborn’s Heart Rate Determination:

Newborn’s Heart Rate Importance

• The Transition from intrauterine to extrauterine life is tough! (some of us are still struggling with it.)
  • Fortunately, the majority of newborns do it successfully with little help.
  • ~10% do require assistance though!

• Determination of Heart Rate is an important aspect of Neonatal / Newborn Resuscitation.
  • Determination of the heart rate within the 60 seconds of life is recommended.
  • If Heart Rate < 100 bpm, then respiratory assistance (ex, PPV) is needed.
  • If Heart Rate < 60 bpm after 30 seconds of PPV, then Chest compressions are indicated.
  • Chest compressions can be stopped AFTER 60 seconds, if the heart rate has improved.
  • Heart rate is the best “measure” of the newborn’s response to resuscitation.

• Unfortunately, trained providers’ ability to determine the heart rate is NOT reliable! [Chitkara, 2013]

Newborn’s Heart Rate Determination

• The Heart Rate can be assessed in several ways. [Trevisanuto, 2019; Phillipos, 2016]
  • Palpation of the umbilical stump (the way I was taught)
  • Palpation of peripheral pulses
  • Auscultation of the precordium with a stethoscope
  • Pulse Oximetry
  • Three-lead ECG / Cardiac Monitor

• Not all methods are consistent. [Trevisanuto, 2019; Phillipos, 2016; Chitkara, 2013; Katheria, 2012]
  • Rapid and reliable acquisition of the heart rate is challenging!
  • Use of Palpation or Auscultation is inaccurate and leads to errors.
  • While these may still be used, Human Factors may undermine their reliability… and an unreliable method can have devastating consequences.
  • Pulse oximetry is more precise (and offer continuous information), but is affected by poor peripheral perfusion in newborns.

• Current Recommendation is to use 3-lead cardiac monitor as a more objective measure of heart rate. [Trevisanuto, 2019; Mizumoto, 2012]

• But, it is not that simple either: [Agrawal, 2019]
  • Attaching electrodes to wet newborn skin
  • Electrodes can damage premature skin
  • Muscle twitching can produce artifacts
  • Cardiac monitoring is not available everywhere
  • May detect electrical activity despite lack of perfusing pulse (i.e., Pulseless Electrical Activity – PEA)
  • Attaching electrodes can be delayed by the initial attempts to dry and stimulate the child.
    • One method may help eliminate this issue [Gulati, 2018]
    • Prearranging the electrodes such that they adhere to the neonate’s posterior thorax once placed supine on the warmer shortens the time to determination of heart rate.

• Other options:
  • Portable Doppler Ultrasound [Agrawal, 2019; Phillipos, 2016]
    • May be able determine heart rate faster than cardiac monitor.
    • Audible heart rate is able to be interpreted by all care providers.
    • Detects flow, so may distinguish PEA.
  • A mobile application (Neo Tap Advanced Support) [Cavallin, 2019; Binotti, 2019]
    • Calculates the heart rate based on provider tapping the screen in unison with the palpated or auscultated heart rate.
    • Removes the need for provider to do math (and doing math can be difficult).
  • There are various other new technologies being evaluated (so something more easily used and more reliable could just be on the horizon). [Kevat, 2017; Phillipos, 2016]

Moral of the Morsel

• Not a Simple Task! Determination of the newborn’s heart rate is critical… and challenging to do (even for experienced providers).
• Don’t let your pride get in the way! When fast and reliable matter… your ability to palpate the pulse is not the best option.
• Get the Monitor Set Up EARLY! Or… if you have a portable doppler ultrasound… just be ready to determine that heart rate within 60 seconds!

References