#131: New Kids on the Block: Special Care Nursery

January 29, 2025 | By Sam Masur

Audio

Summary:

Dr. Colleen Brennan, academic neonatologist at Washington University and director of neonatal outreach, walks us through the first few hours of a baby’s life when things don’t go as planned! She covers critical topics like recognizing respiratory distress and apnea in a neonate, practical tips for corrective steps in newborn resuscitation, how low is too low in neonatal blood glucose, and when to think about etiologies outside of normal transitional physiology!

Newborn Nursery (Special Care) Pearls

1. A newborn without respiratory effort is apneic and needs us to breathe for them!
2. When providing positive pressure, look for good, symmetric chest rise with breaths.
3. Oxygen saturations should be 70% by 3 minutes of life and can take up to 10 minutes to achieve goal saturations
4. If a baby stays on CPAP for more than a few hours (Dr. Brennan uses 6 hours as her cutoff), consider broadening the differential beyond TTN to other common causes of respiratory distress in the newborn like respiratory distress syndrome, pneumonia, pneumothorax, and sepsis (use the Kaiser Permanente neonatal sepsis calculator!).
5. Newborns have physiologic hypoglycemia as they go from continuous dextrose in utero to bolus feeds – a term or near-term baby’s blood sugar should be >40 mg/dL in the first 4 hours and >45 mg/dL from 4-48 hours of life.
6. The Sugar Babies study showed us that 40% dextrose gel + any kind of feed should be first line treatment for hypoglycemia.

Newborn Nursery (Special Care) Notes

The Delivery Room

Taking care of someone’s baby is an honor – families may remember you for years to come. If a baby requires intervention, remember to be transparent with families and establish trust!

There are several common maternal conditions that increase a term or near-term baby’s risk for apnea or respiratory distress. Babies with prenatal selective serotonin reuptake inhibitor (SSRI) exposure are more likely than unexposed infants to experience apnea (Ferreira 2007). Newborns who don’t undergo spontaneous labor are at increased risk for transient tachypnea of the newborn (TTN) while infants of mothers with insulin-dependent diabetes are born with a relative deficiency of surfactant and are more likely to experience respiratory distress out of proportion to their gestational age.

Neonatal Resuscitation

When attending a delivery, the most important initial step is recognizing apnea – a baby without respiratory effort after being warmed, dried and stimulated needs us to breathe for them using positive pressure ventilation (PPV). Most institutions use a T-piece resuscitator – this is preferred over a flow-inflating or bag valve mask since it delivers consistent peak inspiratory pressures (PIP). Up to 10% of term babies will need some sort of respiratory support after birth!

A baby has oxygen saturations around 60% in utero. While some institutions list the expected saturations by minute of life in the delivery room, Dr. Brennan simplifies this by remembering 70% at 3 minutes and goal saturations by 10 minutes.

Corrective Steps in Resuscitation: MR SOPA

These steps should be taken in order with the goal of achieving a heart rate >100 while providing PPV (Neonatal Resuscitation Program). Dr. Brennan reminds us to watch for symmetric and adequate chest rise as a sign of adequate ventilation.

Mask – the mask should cover the baby’s nose and mouth. If achieving adequate seal is difficult, you can use a second person to either help hold the mask or provide ventilation.

Reposition – a baby’s airway is more anterior than that of an older child or adult. Try to achieve a “sniffing” position – this is head midline with the chin tilted up to open the airway.

Suction – you can use a catheter or bulb suction, but always suction the mouth first.

Open the mouth – Dr. Brennan recommends using a finger to open the mouth and move the tongue.

Pressure – babies start at 20 cm H2O for peak inspiratory pressure (PIP) so this next step is increasing to 25 cm H2O.

Alternate airway – this can be an endotracheal tube or a laryngeal mask.

When intubating a baby, make sure the bed is at a height that works for you (we don’t squat and intubate!) and ask the people around you to hand you equipment (suction, endotracheal tube) so you never take your eyes off the vocal cords once you see them! Sometimes a shoulder roll (a small towel from the delivery room, rolled up and placed under the shoulders) can help optimize the line of sight from the baby’s mouth to the vocal cords by allowing for optimal neck extension.

Transient Tachypnea of the Newborn

Transient tachypnea of the newborn is caused by delayed resorption of fetal lung fluid from the lungs. Babies born without significant spontaneous labor are at increased risk of TTN since fetal lung fluid clearance starts with the maternal epinephrine and glucocorticoid surge of labor! TTN typically presents as tachypnea and/or increased work of breathing but is not often associated with significant hypoxia or respiratory acidosis (Hagen 2017). On chest x-ray, this classically looks like “fluid in the fissure” – typically on the right side in the fissures between lung lobes. A term or near-term baby requiring continuous positive airway pressure (CPAP) outside the delivery room most likely has TTN – Dr. Brennan counsels families that this is not uncommon and often resolves in several hours. A baby with mild tachypnea and otherwise reassuring vital signs and appropriate work of breathing can even safely go skin to skin with Mom!

When evaluating a baby off respiratory support, watch respiratory rate (consistently >60 is tachypnea), work of breathing (nasal flaring – a baby’s attempt to increase diameter of the upper airways – in addition to retractions and grunting) and oxygen saturations. Some babies can take 24 hours or more to fully resolve TTN.

Expanding the Differential

Most babies with TTN can come off respiratory support by 2-3 hours of life. A chest x-ray can help look for other causes of respiratory distress like pneumonia (consider risk factors for infection like group B strep positivity or prolonged rupture of membranes), respiratory distress syndrome or pneumothorax. Dr. Brennan typically uses the cut-off of 6 hours of life with respiratory support to consider expanding her differential diagnosis. When it comes to evaluating for sepsis, she encourages us to rely on the Kaiser Permanente Newborn Sepsis Calculator for an evidence-based approach to sepsis evaluations. The website even describes its definition of the risk categories (“well-appearing”, “equivocal” and “clinical illness”) if you click on each of these terms!

Hypoglycemia

Defining hypoglycemia

Although there is ongoing debate about the definition of hypoglycemia in the neonate, the American Academy of Pediatrics recommends the following cutoffs:

•   blood sugar should be greater than 40 mg/dL in the first 4 hours of life
•   blood sugar should be greater than 45 mg/dL from 4-48 hours of life

Many infants have physiologic hypoglycemia in the newborn period as they adjust from continuous glucose through the placenta to bolus feeds!

Understanding hypoglycemia

Infants of diabetic mothers (IDM) are at risk for hypoglycemia – in utero they had a continuous infusion of high levels of dextrose and therefore upregulated their own insulin secretion. Unfortunately, at birth, as they lose this rich supply and move to bolus feeds, they risk hypoglycemia until their insulin levels normalize. Other common risk factors for hypoglycemia include conditions that decrease glycogen stores like small for gestational age (SGA) or intrauterine growth restriction (IUGR). Babies large for gestational age (LGA) are also at risk, thought to be due to undetected maternal gestational diabetes. Other less common causes include perinatal stress and a broad range of genetic and metabolic disorders. In a hypoglycemic baby, look for signs of hypoglycemia like uncoordinated feeding, irritability, sleepiness or jitteriness.

Managing hypoglycemia

The Sugar Babies Study showed us that for babies >35 weeks gestational age, 40% dextrose gel in addition to a feed (this can be breast, bottle, even nasogastric tube!) is a safe and effective first-line treatment for neonatal hypoglycemia. A blood glucose should be repeated one hour after the completion of the feed. For babies not responding to dextrose gel or requiring multiple gel treatments, a bolus of IV dextrose 10% is in order. Dr. Brennan recommends 2 mL/kg followed by an infusion of dextrose-containing fluids – the dextrose bolus will lead to increased insulin secretion from baby thus the continuous infusion is important to prevent worsening hypoglycemia afterwards.

Goal

Listeners will be exposed to common complications in the first few hours of life in a term or near-term infant to develop a stepwise approach for resuscitating a newborn with apnea or respiratory distress, explain the pathophysiology and clinical course of TTN, and recognize the initial diagnosis and management of hypoglycemia in the term or near-term infant.

Learning Objectives

After listening to this episode listeners will… 

1. Recognize the importance of immediate PPV in the neonate with apnea or a heart rate <100.
2. Recall the corrective steps (MR SOPA) for PPV and feel comfortable with the practical execution of each.
3. Describe the pathophysiology of TTN and how this relates to its risk factors and expected clinical course.
4. Recognize when an infant’s clinical appearance deviates from that expected in TTN and the resources available to evaluate for other causes like sepsis, pneumothorax, pneumonia or RDS.
5. Recall the transitional physiology of newborn blood glucose levels.
6. Describe an initial approach to the management of neonatal hypoglycemia.

Disclosures

Dr Brennan reports no relevant financial disclosures. The Cribsiders report no relevant financial disclosures.

Citation

Marshall CS, Chisholm J, Brennan C, Masur S, Berk J, Chiu C. “#131: New Kids on the Block: Special Care Nursery.” The Cribsiders Pediatric Podcast. https:/www.thecribsiders.com/ January 29, 2025.