CHAPTER 13 NEONATAL AND PEDIATRIC RESPIRATORY CARE
PRETEST QUESTIONS
1. An APGAR score of 5 is determined 5 min after delivery of a term infant. Which of the following should be done at this time?
2. The foramen ovale and ductus arteriosus remain patent in infants with persistent fetal circulation as a direct result of which of the following?
3. Which of the following is not an indication for nasal CPAP in an infant?
4. Which of the following are complications of an umbilical artery catheter (UAC)?
5. Which of the following may occur as a result of cold stress to an infant?
6. An elevation in the levels of chloride in sweat is diagnostic for which of the following lung conditions?
REVIEW
1. The term high-risk infant describes an infant who is at greater risk of death or who has a higher probability of a permanent disability.
a. The Ballard scoring system is one of the most accurate means of estimating the baby’s gestational age.
b. The Ballard system scores the infant on neuromuscular criteria and external physical characteristics.
c. Each specific sign is worth a given number of points, and the infant is given all or part of those points, depending on the assessment of that particular sign or characteristic.
d. Points from each assessed area are totaled and plotted on a graph, which determines the infant’s gestational age.
e. Areas assessed include skin thickness, color and transparency of skin, amount of vernix present on the infant, plantar creases, posture, and muscle tone.
g. The calculated gestational age can then be plotted on a graph, along with the infant’s birth weight, to determine whether the infant is appropriate for gestational age (AGA), small for gestational age (SGA), or large for gestational age (LGA).
c. The Apgar assessment is done at 1 min after delivery to determine whether immediate intervention is required and again at 5 min after birth.
(1) Score of 7 to 10 is normal; requires routine observation, suction upper airway with bulb syringe, dry the infant, and place under a warmer.
(3) Score of 0 to 3 indicates severe asphyxia; requires immediate resuscitation with ventilatory assistance.
e. The 5-min Apgar score is useful in determining the infant’s response to intervention; a score of less than 6 is associated with major complications and treatment in an intensive care nursery.
f. The five assessed signs in the Apgar scoring system may be more easily remembered with the use of the following acrostic:
Exam Note(5) Grunting: An audible expiratory grunt, caused by the infant partially closing the glottis during exhalation to prevent alveolar collapse, is a common sign of respiratory distress in infants.
c. Each assessed area is worth from 0 to 2 points; the lowest score indicates minimal distress (as opposed to the highest score being the best in the Apgar scoring system).
| pH | 7.35 to 7.45 (no less than 7.25 at birth) |
| PaCO2 | 35 to 45 mm Hg |
| PaO2 | 50 to 70 mm Hg |
| HCO3− | 20 to 26 mEq/L |
| BE | −5 to +5 |
a. The O2 hood is the recommended method for delivering O2 in the range of 21% to 100% to the infant.
b. A heated nebulizer connected to an O2 blender is the most common method of O2 delivery. The aerosol tubing connects into the back of the hood. If a blender is used to regulate the O2 percentage, the nebulizer must be set on 100% so that no air entrainment occurs, which would alter the blender percentage.
c. A heated humidifier (Cascade or pass-over) is often used rather than a nebulizer to prevent overhydration of the infant.
d. The percentage of O2 should be analyzed continuously with an O2 analyzer. A port in the top of the hood makes analyzing possible. The O2 percentage should be analyzed as close to the infant’s airway as possible because the percentage of O2 is somewhat higher at the bottom of the hood as opposed to the top.
e. A heated nebulizer or humidifier should be used because cold gas blowing on the infant’s face may induce apnea and colder temperatures in the hood may increase the infant’s O2 consumption.
g. Temperatures inside the hood should be closely monitored through a port in the top of the hood to avoid overheating or underheating the infant.
h. Noise levels inside the hood have been proven to be a source of hearing loss to the infant. To keep noise levels to a minimum, nebulizers that entrain air should not be used because they produce increased noise levels.
a. Nasal catheters and cannulas are available in infant sizes and are most commonly used for long-term O2 therapy in the treatment of bronchopulmonary dysplasia (BPD) and other chronic diseases.
b. The flowmeters used to deliver O2 through the catheter or cannula should be calibrated so that increments of 0.25 and 0.50 L/min can be used.
a. An enclosed device used with neonates that has the capability of controlling FiO2, humidity, and environmental temperature.
c. The FiO2 is controlled with an air entrainment device. A metal red flag is attached to a mechanism that blocks the entrainment port, which allows for an FiO2 of greater than 0.40 when the flag is in the up position. With the flag in the down position, the entrainment port remains open and delivers an FiO2 of 0.4 or less.
d. The oxygen concentration can be inconsistent and variable when the enclosure is opened to provide care to the infant. Because of this, oxygen is often delivered through an oxygen hood placed over the infant inside the incubator.
e. As with oxygen hoods, it is very important to minimize noise levels within the incubator to prevent hearing impairment in the infant.
Exam Note
Exam Note
Exam Note
Decreased venous return is less likely to occur if the infant has decreased static lung compliance caused by respiratory distress syndrome (RDS). Infants with normal lungs would be more susceptible to this complication because the lungs are more compliant and the airway pressure is more easily transferred to the superior and inferior vena cavae.e. Blood must be drawn frequently to determine ABG levels if CPAP is used to monitor PaCO2 levels. If the PaCO2 begins to rise, mechanical ventilation is necessary.
f. The use of nasal CPAP for infants is based on the fact that infants are obligate nose breathers. If the baby cries, CPAP is lost.
d. Initially, the high arterial O2 levels cause constriction of the retinal vessels. As the vessels remain constricted, new vessels form in an attempt to oxygenate the retina.
e. This growth of new vessels leads to hemorrhaging within the retina, retinal detachment, and blindness.
f. The degree of blindness varies in each situation and infants exposed to supplemental O2 should have an eye examination before discharge.
g. ABG samples should be obtained frequently while the infant is receiving O2 to determine the O2 level in the blood. If the infant has a ductal shunt (discussed later in this chapter), the blood must be drawn from the right radial, brachial, or temporal artery to measure the PaO2 of the blood going to the head. If no shunt exists, blood may be drawn from the UAC or any peripheral artery.
b. Insert the catheter into one of the two umbilical arteries. After insertion, determine the position of the catheter with a radiograph.
c. Rest the tip of the catheter in the descending aorta at either one of the following vertebral levels as seen on a radiographic image
d. Secure the catheter in place with umbilical tape or sutures attached to the umbilical stump, and then tape the catheter to the abdomen.
(2) Thromboembolism (To help prevent this, flush the line with heparin after a blood sample is drawn.)
i. If there is inadequate perfusion to the lower extremities, blanching or cyanosis of the legs or feet will be evident. Withdraw or replace the catheter.
a. Draw arterial blood from one of several arteries in the neonate, including the radial, brachial, temporal, and posterior tibial arteries.
b. The radial artery is the most common site because of its easy accessibility, good collateral circulation, and lack of immediately adjacent nerves or veins.
c. Generally, use a 25- or 26-gauge needle to puncture the artery at a 35 to 45 degree angle to the artery. Face the bevel of the needle up when performing radial puncture.
d. Locate the radial artery by finding a radial pulse or by placing a transilluminator under the back of the wrist. This lighted device aids in locating the artery.
e. Because the radial artery in a neonate is very small, it is not uncommon to insert the needle completely through the artery. If, after advancing the needle, you do not obtain blood, withdraw the needle slightly until blood enters the needle.
f. When you obtain an adequate amount of blood, withdraw the needle and apply pressure to the puncture site for approximately 5 min.
g. Remove any air bubbles in the sample before analysis. If this is not done, the blood gas analysis will show erroneous values, indicating a high PaO2 and low PaCO2.
a. Normally obtain arterialized capillary blood from the heel of the neonate by using a lancet to puncture the capillary.
b. Warm the infant’s foot for several minutes (usually by wrapping a warm moist diaper around the foot) to cause peripheral vasodilation, which improves capillary perfusion and arterializes the capillary blood.
c. Then clean the heel with alcohol and puncture the capillary using an appropriate device. Use a heparinized glass capillary tube for the blood.
d. Take care not to squeeze the heel because this may cause damage to the foot and contaminate the sample with venous blood and interstitial fluid.
e. Make sure the capillary tube is as close to the puncture site as possible to avoid contaminating the sample with room air.
f. Once you obtain the sample, apply pressure to the heel until the bleeding stops, and then apply an adhesive bandage.
g. Capillary blood samples offer fairly reliable correlations for arterial pH and PCO2 but are unreliable for PO2 values. The capillary PO2 (PCO2) may be low, but the PaO2 may actually be high, which increases the risk of ROP or BPD. It is also possible to have a high PCO2 when the PaO2 is low, which risks hypoxic damage. Monitor arterial PO2 levels periodically to prevent this potential hazard. Normal PCO2 is 40 to 50 mm Hg.
1. By applying blood gas electrodes over the skin, you may monitor the neonate’s PaO2 and PaCO2 continuously without having to perform arterial sticks as frequently.
2. Attach the probe to the skin, which warms the skin to 40° to 42° C and results in vasodilation and increased perfusion to the dermal layer of the skin. O2 and CO2 diffuse through the skin in concentrations similar to those in arterial blood.
a. The heated probe may burn the skin. Change the location of the probe every 3 to 4 h to prevent this. In the more premature infant with very fragile skin, change the probe position every 2 h.
b. The infant must have adequate perfusion to the area of the skin where the probe is attached to provide accurate readings.
c. Inaccurate readings occur if the probe is inadequately heated, the monitor is not calibrated properly, or the probe becomes loose and air comes between the probe and the skin.
4. The monitor requires calibrating during the initial setup and after probe position changes. This is done with the sensor off the infant and is calculated by (PB: 47 mm Hg) × 0.21. (Math shortcut for exam: If the corrected PB is 700 mm Hg, then use 7 × 21.)
5. After calibration, the monitor takes 20 to 30 min to equilibrate before accurate readings are displayed.
1. Monitoring arterial O2 saturation with a pulse oximeter (SpO2) is becoming a popular method of determining the oxygenation status of infants.
2. Oximetry uses photometrics (a light beam shining through the skin or nailbed) to determine SaO2; therefore, the burning of the skin that is possible with transcutaneous monitoring is not a factor. For more detailed information on oximetry, see chapter 10.
II. NEONATAL CARDIOPULMONARY DISORDERS
1. Definition: a syndrome affecting premature infants that is caused by inadequate amounts of pulmonary surfactant, which leads to massive atelectasis and hypoxemia. (Also known as hyaline membrane disease [HMD].)
b. Lecithin–sphingomyelin (L : S) ratio of less than 2 : 1. These lipid levels may be obtained from amniotic fluid to determine the maturity of the surfactant. A ratio of more than 2 : 1 indicates mature surfactant.
a. Surfactant lines the inner surface of alveoli, decreasing the surface tension and thereby reducing their tendency to collapse.
b. Immature surfactant or decreased surfactant production, as seen in IRDS, leads to alveolar collapse, decreased lung compliance, hypoxemia, and metabolic acidosis.
c. Alveolar surface tension increases from the lack of surfactant, which results in fluid being pulled into the alveoli. Because of damage to the capillary endothelial cells by acidosis and hypoxemia, the fluid entering the alveoli contains protein and the blood-clotting component fibrin. This makes the alveoli very stiff (noncompliant) and causes the hyaline membrane formation.
1. Definition: a form of chronic lung disease seen in infants with severe RDS after prolonged positive pressure ventilation and supplemental O2. Dysplasia refers to abnormal development, in this case, of the bronchi and lungs.
a. Although the cause of BPD is widely debated, it is thought to occur from prolonged (more than 7 days) exposure to high concentrations of O2 with positive pressure ventilation.
b. A major cause of BPD is thought to be high inspiratory pressures associated with mechanical ventilation, which leads to barotrauma.
(2) Stage 2 occurs 4 to 10 days after birth and includes necrosis, repair of alveolar and bronchial epithelium, and emphysematous changes.
a. O2 therapy to maintain PaO2 between 50 and 70 mm Hg (helps prevent pulmonary hypertension resulting from hypoxemia)
f. Maintenance of fluid balance or diuretic administration to minimize the infant’s increased risk of cor pulmonale, pulmonary edema, and CHF
1. Definition: Aspiration of meconium is most commonly associated with full-term or postterm infants. Meconium is discharged in the first fetal bowel movement and is composed of mucus, vernix, epithelial cells, and amniotic fluid.
b. Infants in utero breathe in a shallow manner, moving amniotic fluid into and out of the oropharynx. However, if the infant is stressed or asphyxiated, the breaths are much deeper and meconium may be aspirated through the vocal cords and into the lungs.
c. The postterm infant is at greater risk of meconium aspiration because less amniotic fluid is present; therefore, there is less dilution of the meconium.
d. Even if the meconium is present only in the mouth or the glottic area, aspiration may occur with the infant’s first few breaths.
a. The substances that make up meconium cause it to be very thick; therefore, if aspirated, it plugs airways, which leads to atelectasis and increased airway resistance.
b. Generally, airflow passes through the obstruction during inspiration but gets trapped during expiration as the airway diameter decreases, which results in hyperinflation.
d. Infants with this condition often have patent ductus arteriosus (PDA) (discussed later) caused by the intrauterine hypoxia. Hypoxia causes pulmonary vasoconstriction, which prevents the ductus arteriosus and foramen ovale from closing, resulting in a right to left shunt.
a. If meconium is observed during delivery, suction the infant’s oral and nasal pharynx once the head is delivered and before the first cry, to prevent aspiration of the meconium.
b. Immediately after delivery, intubate and suction the infant to remove meconium from the lower airway if the infant is not vigorous.
c. Do not start positive pressure ventilation until all meconium is cleared because this would push it farther into the airways.
1. Definition: a condition in which fetal blood circulation through the heart persists after birth because of pulmonary hypertension.
a. Normal fetal circulation: Blood flow through the heart of the infant in utero differs from the pathway the blood takes after birth. Only about 10% of blood returning to the right side of the infant’s heart flows on into the pulmonary circulation. The other 90% or so of the blood volume in the right side of the heart shunts over to the left side via two pathways. One is through the foramen ovale, a pathway that allows blood to flow from the right atrium into the left atrium. The second area where shunting occurs is through the ductus arteriosus, which is a communication between the pulmonary artery and the descending aorta.
b. These two communications between the right and left heart are kept open in utero because of the high pressure in the pulmonary vasculature. After the infant is delivered and begins breathing O2 from the air, pulmonary vasodilation occurs, reducing the pulmonary hypertension and allowing the foramen ovale and ductus arteriosus to gradually close.
c. If closure of these two pathways does not occur, blood bypasses the lungs and is shunted directly into the left side of the heart and out to the body without oxygenation. PaO2 levels do not increase as FiO2 is increased.
a. The condition is most common in full-term or postterm infants because the pulmonary vessels are more reactive to hypoxia, leading to pulmonary vasoconstriction
Exam Note
Any condition that results in increased pulmonary vascular resistance (PVR) can cause PPHN.
b. This results in right-to-left shunting that causes hypoxemia that is not responsive to O2 therapy.
d. More than a 15-mm Hg difference in the PaO2 between preductal blood (radial or temporal artery) and postductal blood (umbilical artery) with the use of 100% O2 (i.e., preductal PaO2 is higher than postductal PaO2)
Exam Note
Exam Note
Exam Note(5) Dopamine, which increases systemic vascular resistance and thus reduces the right-to-left pressure gradient, which decreases shunting
d. Weaning from mechanical ventilation should be done slowly because small decreases in ventilator respiratory rates, peak inspiratory pressure, and FiO2 may result in a return to shunting, which will require even higher ventilator variables (respiratory rate, PIP, FiO2) than before.
Exam Notee. Furosemide (Lasix) is indicated for treatment of the edema, and indomethacin is often used to help constrict the ductus so that blood cannot flow through it.
III. Extracorporeal Membrane Oxygenation (ECMO)
ECMO is not specifically mentioned on either exam matrix.
B. In this procedure, venous blood is removed from the right atrium via an indwelling catheter and pumped through a membrane where the blood is oxygenated. The blood is then returned to the infant via the right jugular vein.
IV. AIRWAY DISORDERS OF THE PEDIATRIC PATIENT
CRT Exam Content Matrix: IA2, IA6, IB1a, IB1c, IB7d, IB8, IC1, IIA12a, IIID5a, IIIE1, IIIF2c-d
RRT Exam Content Matrix: IA2, IA6, IB1a, IB8, IIIE1
Exam Note1. Definition: a bacterial infection of the epiglottis, most commonly affecting children 3 to 7 years old, resulting in inflammation and edema of the supraglottic area
b. Inflammation leads to swelling of the supraglottic area, resulting in a sudden onset of severe respiratory distress and often precipitating a life-threatening situation.
k. The epiglottis is swollen and red on direct visualization, which may result in complete upper airway obstruction; thus, if direct visualization is attempted, intubation and tracheostomy equipment must be readily available. Avoid direct visualization if possible.
l. Initial ABG levels reveal hypoxemia and respiratory alkalosis, progressing to respiratory acidosis if hypoxemia is not reversed.
a. A lateral neck x-ray film will reveal a swollen epiglottis, known as the thumb sign because it resembles the distal end of a thumb.
1. Definition: upper airway obstruction resulting from inflammation of the larynx and subglottic area; most commonly seen in children 8 months to 4 years old
b. May result from adenovirus or respiratory syncytial virus (RSV) infection (discussed later in this chapter)
a. Swelling and edema of the laryngeal and subglottic area results from inflammation that leads to a narrowing airway lumen.
b. The subglottic area is the narrowest portion of the infant’s or child’s airway, so a small degree of edema causes a significant reduction in the cross-sectional area.
i. Initial ABG levels reveal hypoxemia and respiratory alkalosis, progressing to respiratory acidosis if hypoxemia is not reversed.
a. Young children often place objects in their mouths and, in some instances, aspirate the object into the respiratory tract.
a. The aspirated object usually lodges in the right mainstem bronchus because of its angle of bifurcation from the trachea.
b. Certain objects (especially peanuts) may result in a chemical bronchitis that causes mucosal swelling and edema.
c. Commonly, infection distal to the obstruction occurs, resulting in abscess, pneumonia, or bronchiectasis.
b. A mediastinal shift away from the side of the aspiration occurs during expiration, as the affected lung becomes hyperinflated.
Inspiratory and expiratory chest films should be obtained to determine whether a mediastinal shift is present.c. Bronchodilator therapy followed by postural drainage and percussion is often successful in removing the object before bronchoscopy.
1. Definition: an inflammation of the bronchioles that is most commonly seen in children during the first 2 years
a. The viral infection causes inflammation of the bronchioles, mucosal edema, and spasms of the bronchiolar smooth muscle.
(3) Ribavirin (antiviral drug), administered via a SPAG nebulizer for 12 to 18 h daily through an O2 hood for 3 to 7 days. This therapy is declining in use and, in fact, is no longer covered on the NBRC exams.
1. Definition: a hereditary disease affecting the exocrine glands of the body that results in the production of thick mucus from these glands. The glands most commonly affected are located in the pancreas, the sweat glands, and the lungs.
b. The mother and father both must be carriers of this recessive gene. Each child of the couple has a one-in-four chance of having the disease.
a. Large amounts of thick mucus are produced as a result of the abnormally large numbers of bronchial glands and goblet cells located in the tracheobronchial tree.
b. Thick mucus stagnates in the airways, leading to airway obstruction and facilitation of bacterial growth.
d. Abnormalities in the pancreatic ducts and glands result in inadequate absorption and digestion of food, causing malnutrition if not properly treated.
a. Aerosolized bronchodilator therapy with a mucolytic, such as acetylcysteine (Mucomyst) or dornase alfa (Pulmozyme), followed by chest physical therapy (flutter valve, PEP therapy, oscillating vest)
POSTCHAPTER STUDY QUESTIONS
1. What five conditions are assessed in the Apgar score?
2. Describe the appropriate intervention for the following Apgar scores: 0 to 3; 4 to 6; and 7 to 10.
3. What is often the first sign of respiratory distress in the infant?
4. List the normal ABG levels for an infant.
5. List six indications for nasal CPAP.
6. List five complications of CPAP.
7. List two hazards of O2 therapy in the neonate.
8. Describe where the tip of the UAC should rest when properly positioned.
9. List four advantages of a UAC.
10. List four complications of a UAC.
11. List six clinical manifestations of IRDS.
13. List eight clinical manifestations of BPD.
14. Describe the chest x-ray findings in infants with BPD.
15. List the treatment modalities for BPD.
16. List the causes of meconium aspiration.
17. List eight clinical manifestations of meconium aspiration.
18. List eight conditions that accompany PPHN.
19. List five clinical manifestations of PPHN.
20. List the treatment modalities for PPHN.
21. List the causes of epiglottitis.
22. List 12 clinical manifestations of epiglottitis.
23. Describe the classic x-ray finding for diagnosis of epiglottitis.
24. List the treatment modalities for epiglottitis.
Hess D, Respiratory care principles and practice, ed 1, Philadelphia, Saunders, 2002.
Scanlan C, Spearman C, Sheldon R. Egan’s fundamentals of respiratory care, ed 5. St Louis: Mosby; 1990.
Walsh BK, Czernnske MP, DiBlasi RM. Perinatal and pediatric respiratory care, ed 3. St Louis: Saunders; 2010.
Whitaker K. Comprehensive perinatal and pediatric respiratory care, ed 3. Albany, NY: Delmar; 2001.
Wilkins RL, Stoller JK, Kacmarek R. Egan’s fundamentals of respiratory care, ed 9. St Louis: Mosby; 2009.
