NICU

NICU

Naureen Memon

Miranda Bik-Yin Ip

Phuoc V. Le

Joseph H. Chou

Delivery Room Management

Intrapartum Fetal Heart Rate Monitoring

Baseline fetal HR: Normal HR is 110–160 bpm.
- Fetal tachycardia: HR >160 bpm. Causes: Maternal or fetal fever/infxn, fetal hypoxia, thyrotoxicosis, maternal meds (β-agonists and parasympathetic blockers)
- Fetal bradycardia: HR <110 bpm, w/ severe bradycardia <90 bpm. Causes: Hypoxia, complete heart block, maternal meds (β-blockers)
Variability: Absence of beat-to-beat variability may indicate: Severe hypoxia, anencephaly, complete heart block, maternal med effect (narcotics, MgSO₄)
Accelerations: Are associated with fetal movement and indicate fetal well-being
Decelerations:
- Early: Assoc w/ uterine compression of fetal head. Benign; not assoc w/ fetal compromise
- Variable: Assoc w/ umbilical cord compression. Can cause perinatal depression, but if beat-to-beat variability is maintained, then fetus is not compromised
- Late: Assoc w/ uteroplacental insuff. If beat-to-beat variability maintained, fetus usually well compensated. If not, then may represent significant fetal hypoxia

APGAR Scoring

	0	1	2
Heart rate	Absent	<100 min	>100 min
Respiratory effort	Absent	Weak cry; hypoventilation	Good, crying
Muscle tone	Flaccid	Some flexion	Active motion
Reflex irritability	No response	Grimace	Cry or active withdrawal
Color	Blue or pale	Acrocyanotic	Completely pink

Gestational Age and Birth Weight Classifications

Maturity by Gestational Age
Preterm: <37 wk	Term: 37–42 wk	Postterm: >42 wk
Birth weight
Low birth weight (LBW) : <2500 g
Very low birth weight (VLBW): <1500 g
Extremely low birth weight (ELBW): <1000 g
Birth Weight/length for Gestational Age
Small for gestational age (SGA): Weight or length <2 SD
Appropriate for gestational age: Weight or length within 2 SD
Large for gestational age: Weight or length >2 SD
Asymmetric IUGR (delayed fetal weight gain with sparing of length and head growth) acute malnutrition or placental insufficiency; has potential for catch-up growth
Symmetric IUGR (delayed fetal weight gain w/ comparable delays of length and head growth) prolonged malnutrition, genetic processes, or congenital anomalies; has less potential for catch-up growth
(Pediatr Rev 2006;27:224)

Be sure to plot length, weight, and head circumference on every infant!
New Ballard score to assess neuromuscular and physical maturity of infants, especially in those that are premature or if dates are unknown
- Can be obtained online at www.ballardscore.com
- For preterm growth charts, go to www.medcalc.com/growth

NRP Algorithm

(Neonatal Resuscitation Textbook. 5th ed. 2006)

Neonatal Resuscitation

When preparing for a high-risk delivery, have an estimated weight and GA so that appropriate ETT, umbilical catheter size, and drug doses can be calculated
- Suggested ETT size and depth of insertion according to weight and GA
- Depth of insertion can be estimated by weight in kg + 6 cm

Weight, g	Gestational Age, wk	Tube Size, mm (inner diameter)	Depth of Insertion from Upper Lip, cm
<1000	<28	2.5	6.5–7
1000–2000	28–34	3.0	7–8
2000–3000	34–38	3.5	8–9
>3000	>38	3.5–4.0	>9
(Pediatrics 2000;106:e29)

Sepsis Rule-Out Algorithms

Management of asymptomatic infants born at ≥35 wks gestation with risk factors for early-onset sepsis; protocols vary per institution.
Indications for intrapartum antibiotic prophylaxis (IAP)
- + GBS cx unless elective C-section w/o labor or ROM
- GBS bacteriuria in index pregnancy
- Prior baby w/ GBS disease
Maternal temp >100.4°F, even w/ negative GBS culture
GBS status unknown and ROM >18 hr, labor <37 wk or maternal temp >100.4°F

* see above text for IAP indications

MGH guidelines: Management of asymptomatic newborn at risk for sepsis
- Abnormal WBC: Total WBC <5000 or I:T ratio >0.2
- I:T = number of immature PMNs/total number of PMNs
- IV Abx:
  - Ampicillin >2 kg give 50 mg/kg/dose q8; ≤2 kg give 50 mg/kg/dose q12
  - Gentamicin ≥35 wk GA, give 4 mg/kg/dose q24h, <35 wk GA, give 3 mg/kg/dose q24h
- Of note, maternal fever w/i 1 hr of delivery should be Rx’d as intrapartum fever
- Mother w/ prior child w/ GBS dz; baby should have CBC/diff, bld cx, and Abx if IAP <4 hr or if intrapartum fever >100.4°F
The above are for management of asymptomatic infants born ≥35 wks’ gestation
Remember that these are only guidelines and do not replace clinical judgment.

Basic NICU Management

NICU Calculations and Formulas

For a number of excellent online NICU calculators go to www.nicutools.org

Ventilatory Support and ECMO

(see PICU chapter)

Vascular Access

(formulas may not be appropriate for SGA or LGA infants)

Always check placement with babygram.
Umbilical artery catheter (UAC): For arterial BP monitoring or freq ABGs
- Low-line (cm) [asymptotically equal to] BW (kg) + 7 (want L3-L5, just above aortic bifurcation)
  - Assoc w/ more vasospasms of the lower extremities
- High-line (cm) [asymptotically equal to] [3 × BW (kg)] + 9 (want T6-T10, above diaphragm)
  - Assoc w/ risk HTN and ↑ risk IVH, ↓ incidence of cyanosis of lower extremities
Umbilical vein catheter (UVC):
- Normal: [0.5 × UA (cm)] + 1 (want above ductus venosus, at or below RA)
- Low-line: Insert to point of initial blood return (for emergent use)

NICU Testing Guidelines

(Pediatrics 2006;117:572; Am Fam Physician 2007;75:1349; Arch Dis Child Fetal Neonatal Ed 2005;90:452)

Routine Neonatal Testing Guidelines
Test	Gestational Age
Cranial Ultrasound	<32 wk; d of life: 3, 10, 30, then monthly until discharge
Ophthalmologic exams	≤31 wk or <1500 g or 1500–2000 g and high risk; screen at 31 wk corrected GA, but not sooner than 4 wk chronologic age
Hearing tests	BAERS; for all infants before discharge
Car seat tests	<37 wk or <2500 g or with respiratory instability

Fluids, Electrolytes, and Nutrition

Growth parameters and expected weight gain
- Weight <2 kg: Expect gain of 15–30 g/d or 10–20 g/kg/d
- Weight >2 kg: Expect gain of >20 g/d
- W/ preterm, may have initial weight loss of ≤15% (up to 20% in ELBW)
- In term infants, may have initial weight loss of ≤10%
Fluid requirements: Premature infants have greater ECF volumes
- Initial fluid requirements: 60–120 mL/kg/d
  - Term infants ∼60 mL/kg/d
  - ELBW ∼120 mL/kg/d (assuming that they are in the Giraffe incubators)
- Goal after fluid stabilization: 100–150 mL/kg/d
- Fluid restriction may be needed w/ PDA, BPD, CHF, renal failure, cerebral edema
- Insensible loss inc w/: inc skin permeability, inc BSA:weight ratio, phototherapy, radiant warmer beds, respiratory distress syndrome, cold stress, inc activity
- Insensible water loss decreases with double-walled incubators.
- Monitor fluid status by daily weights, UOP, and serum Na, Hct, and BUN levels.
- Fluid loss also results from vomiting, diarrhea, ostomy output, chest tube drainage
- Inadequate hydration can lead to hyperosmolarity and may be a risk for IVH
Parenteral nutrition in preterm infant

Carbohydrate

– GIR (mg/kg/min)= (% glucose in solution × rate of infusion per hr)/(6 × weight (kg)) OR= (% glucose concentration × cc/kg/d)/144

– Initial glucose rate: 4–6 mg/kg/min

– Adjust by 2 mg/kg/min as tolerated, advancing to meet nutritional need

– Limit to <14 mg/kg/min to prevent overfeeding, fatty liver, increased CO₂ production

Protein

– Infants <1500 g BW: Begin at 1–1.5 g/kg/d, advance by 1 g/kg/d to goal of 3–3.5 g/kg

-Infants >1500 g BW: Begin at 1–1.5 g/kg/d, advance by 1 g/kg/d to goal of 2.5–3 g/kg

Fat

– Begin at 1 g/kg/d and advance by 1 g/kg/d to goal of 3 g/kg

– May run lipid via central or peripheral access over 20–24 hr

– Monitor with serum triglyceride, normal range <200 mg/dL

– Essential fatty acid deficiency may occur in <1 wk without lipid source; provide minimum 0.5 g/kg/d 2-3× per wk to prevent

– May need to limit to 2 g/kg/d with extreme hyperbilirubinemia

Total Energy Needs

– 90–100 kcal/kg/d for VLBW and SGA infants

– 80–90 kcal/kg/d for >28 wk and AGA

Additives

– Na: 2–4 mEq/kg/d

– K: 2–4 mEq/kg/d

– Ca: 60–90 mg/kg/d

– Phos: 47–70 mg/kg/d

– Cl: 2–3 mEq/kg/d

– Mg: 4.3–7.2 mg/kg/d

*Ca/phos ratio should be 1.7/1(Modified from Manual of Pediatric Nutrition. 4th ed)

Common total parenteral nutrition orders at MGH
- Fluid orders on DOL #1: NPO and for…
  - Term infants: D₁₀W at a rate of 60–80 cc/kg/d
  - Preterm: D₁₀W at a rate of 80–100 cc/kg/d
- Add electrolytes after adequate UOP & after checking serum lytes at 12–24 hr
- TPN labs:
  - Daily: Na, K, Cl, CO₂, glucose
  - Weekly: Above tests plus Ca, Mg, P, alkaline phosphatase, BUN, creatinine, triglyceride, total protein, albumin, bilirubin, AST, ALT, hematocrit
  - “Feeder-Grower” labs:
    - Hct and Retic: 24–28 wk GA: Weekly, >28 wk GA: Every other wk
    - Chem 10, alk phos:
      - Breast-fed <32 wk: Weekly Na, K, phos, Ca, alk phos
      - Formula-fed <32 wk: Weekly Ca, phos, alk phos
      - All breast-fed with supplement: Weekly lytes, Ca, phos
      - All infants on ProMod: Weekly BUN

	DOL 0	DOL 1	DOL 2	DOL 3	DOL 4	≥DOL 5	Max	Comments
% Dextrose 3.4 kcal/g	10%	Adv by 1%–2% per d based on BG level	Adv by 1%–2% per d based on BG level	Adv by 1%–2% per d based on BG level	Adv by 1%–2% per d based on BG level	Adv by 1%–2% per d based on BG level	Periph/Low UVC = 12.5% Central 20%–22.5% Violated line = 15%	– If fluid needs are ↑↑, % dex may need to be ↓– 45%–60% total cal– Some conditions may need ↑ dex con
Glucose Infusion Rate (GIR) mg/kg/min	4–6	↑ by 1–2	↑ by 1–2	↑ by 1–2	↑ by 1–2	↑ by 1–2	Periph = 11–12Central = 14–16	– Inc GIR as tolerated by serum glucose.– May exceed GIR if clinical condition warrants; not routinely recommended
Amino Acids g/kg/d	1.5	2.5	3	3–3.5	3–3.5	3–3.5	<1.5 kg = 3.5 g/kg>1.5 kg = 3 g/kg	– Essent to growth– Monitor for acidosis– If BUN>30, eval reason ([check mark] NH3)
Intralipid g/kg/d (20% = 2 kcal/cc: 10 kcal/g)	0	>800 g = 1 <800 g Hold	>800 g = 1.5 <800 g Hold	>800 g = 2 <800 g = 0.5	>800 g = 2.5 <800 g = 1	>800 g = 2.5 <800 g = 1.5	3 g/kg (can inc to 3.5 g/kg prn) <800 g [check mark] trig before adv >2 g/kg	– 25%–40% total cal (don’t exceed 60%)– Min 0.5 g/kg needed to prevent EFA def (can dev in 2–3 d)– Limit to 2 g/kg if septic– ↓/hold if trig >200
*MGH Nutrition Guidelines

Enteral Feeds

(Manual of Pediatric Nutrition. 4th ed)

Preterm neonates do not establish coordination of suck, swallow, and breathing until 32–34 wk GA; until then, enteral feeding via NGT (bolus vs. continuous) needed
Enteral nutrition should generally begin as soon as infant is clinically stable.
Initiation and advancement based on BW w/ attention to feeding tolerance
Most premature infants start w/ trophic feeds (low-vol; 10 mL/kg/d) to stim GI hormones, motility, and maturation and to prevent gut atrophy
Once stable, volumes increased slowly as tolerated w/ increments ∼10–20 mL/kg/d, allows for gut adaptation and minimizes risk of complications
Signs of feeding intolerance include: Inc gastric residuals >2×’s previous hr’s rate (continuous feed) or >½ previous bolus, inc in abd distention, vomiting, or bilious residuals, heme + or frank blood in stools, ↑ in apnea or bradycardia with feeds

Respiratory Syncytial Virus (RSV) Prophylaxis

(Pediatrics 2003;112:1442)

Synagis 15 mg/kg IM monthly during RSV season. 1st dose 1 mo before RSV season.
Recommended at discharge (not while in NICU) for:
- <28 wk GA if born <12 mo before start of RSV season
- 29–32 wk GA if born <6 mo before start of RSV season
- 32–35 wk GA if born <6 mo before start of RSV season and w/ 2 risk factors
- Infants <2 yo with chronic lung disease or congenital heart disease
Risk factors: School-aged siblings, day care, exposure to air pollutants, severe neuromuscular dz, congenital abnormalities of the airways, low birth weight (<2500 g), crowded living conditions, multiple birth, family history of asthma

Morbidity and Mortality with BW and GA

(N Engl J Med 2008;358:1700)

Outcome	Birth Weight
	501–760 g	751–1000 g	1001–1250 g	1251–1500 g
Overall Survival	55%	88%	94%	96%
Survival w/ Complications*	65%	43%	22%	11%
*Complications include bronchopulmonary dysplasia, severe intraventricular hemorrhage, necrotizing enterocolitis, or bronchopulmonary dysplasia and severe intraventricular hemorrhage combined.

Pulmonary/Respiratory

Etiologies of Respiratory Distress

(NeoReviews 2005;6:e290)

Parenchymal conditions

– Transient tachypnea of the newborn

– Meconium aspiration syndrome

– Respiratory distress syndrome

– Pneumonia

– Pulmonary edema

– Pulmonary hemorrhage

– Pulmonary lymphangiectasia

Airway abnormalities

– Choanal atresia/stenosis

– Laryngeal web

– Laryngotracheomalacia or bronchomalacia

– Subglottic stenosis

Developmental abnormalities

– Lobar emphysema

– Pulmonary sequestration

– Cystic adenomatoid malformation

– Congenital diaphragmatic hernia

– Tracheoesophageal fistula

– Pulmonary hypoplasia

Mechanical abnormalities

– Rib cage anomalies (e.g., Jeune syndrome)

– Pneumothorax

– Pneumomediastinum

– Pleural effusion

– Chylothorax

Differentiating cardiac and respiratory causes of cyanosis (see Cardiology chapter)
- Cyanosis w/o resp distress, O₂ sat <85% on RA and 100% O₂, likely dx intracardiac shunt
- If O₂ sat ↑ >85% on 100% O₂, either intracardiac shunt vs. pulm cause of cyanosis. Need to perform a full hyperoxia test.
- Hyperoxia test: Obtain baseline right radial (preductal) ABG w/ neonate on RA, then repeat ABG after providing 100% O₂ for 10 min.
  - A Pao₂ of >300 mm Hg is normal, >150 mm Hg suggests pulmonary disease, and 50–150 mm Hg suggests cardiac disease (or severe pulmonary HTN)