Apnea of Prematurity Treatment & Management

Updated: Nov 06, 2016
  • Author: Dharmendra J Nimavat, MD, FAAP; Chief Editor: Ted Rosenkrantz, MD  more...
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Treatment

Medical Care

Goal of medical therapy

The principal goals of treating apnea of prematurity (AOP) are to address its cause and to provide appropriate medical management. For example, bacterial sepsis that causes apnea is treated with antibiotics and other supportive therapies, whereas seizures require anticonvulsants. The use of assisted ventilation to manage severe apnea, bradycardia, and O2 desaturation can be life saving, and assisted ventilation and O2 may be required to prevent injury to the CNS. The primary disease process must be identified and treated.

When all causes of apnea other than prematurity are excluded during the diagnostic work-up, apnea of prematurity is the presumptive etiology. Caregivers must decide which intervention is appropriate given the severity of the patient's apnea, bradycardia, and O2 desaturation. For example, an infant who has an inadequate response to tactile stimulation and O2 administration and who requires airway suctioning and bag-mask ventilation to recover suggests a serious problem.

A useful strategy is to have a protocol that defines escalating treatments for apnea of prematurity. Depending on the frequency and the severity of apnea, bradycardia, and O2 desaturation, common treatments include stimulation (usually tactile), methylxanthine, or assisted ventilation (eg, nasal continuous positive airway pressure [CPAP], mechanical ventilation). [110]

Pantalitschka et al compared 4 modes of nasal respiratory support for apnea of prematurity in very low birthweight infants: intermittent positive pressure ventilation (IPPV) via a conventional ventilator or a variable flow device and CPAP via a variable flow device or a constant flow underwater bubble system. [111] In their randomized controlled trial with a crossover design, episodes of bradycardia or desaturation occurred at a rate of 6.7 per hour with the conventional ventilator in IPPV mode and at a rate of 2.8 and 4.4 per hour with the variable flow device in CPAP and IPPV mode, respectively (< 0.03 for both compared with IPPV/conventional ventilator). Pantalitschka et al concluded that a variable flow nasal CPAP may be more effective than a conventional ventilator in nasal IPPV mode for treating apnea of prematurity.

Stimulation

Tactile stimulation is usually sufficient to terminate an isolated apneic event caused by central apnea. Stimulation akin to that used during neonatal resuscitation (eg, a gentle tap to the sole of the foot or rubbing the back) is often enough to terminate a central apnea. However, other measures may be required to treat an obstructive event or an episode of airway obstruction followed by central apnea.

If the upper airway is obstructed, repositioning the patient's head and neck or gently elevating the infant's jaw may alleviate the occlusion.

Use of a high-flow nasal cannula may open the airway enough to reduce obstructive apnea. As an alternative, high-flow oxygenation through a nasal cannula may be an agonist for receptors in the airway. Nasal irritation due to the cannula may prevent central apnea by causing arousal. Additional research is needed to ascertain the usefulness of high-flow nasal cannulas for treating apnea of prematurity.

Administration of oxygen

Supplemental oxygenation or bag-mask ventilation is indicated in infants with signs of bradycardia or desaturation.

Medical treatment is indicated when apneic episodes number 6-10 or more per day; when the infant does not respond to tactile stimulation; or when an event requires O2 and/or bag-mask ventilation to terminate apnea, bradycardia, and/or desaturation.

Avoid hyperoxia, which may increase the risk of retinopathy of prematurity (ROP).

Administration of carbon dioxide

Carbon dioxide is known to be the natural stimulator of breathing, and a study has shown that if the baseline PCO2 is increased in a premature infant, facilitated by providing a low concentration of inhaled carbon dioxide, this abolishes the apneic events in the premature infants; however, it is not as effective as theophylline and is not practical to deliver constant concentration of carbon dioxide, and, therefore, it should not be done. [112]

Use of CPAP

CPAP has been used to treat apnea in preterm neonates, and it is indicated when the infant continues to have apneic episodes despite achieving a therapeutic serum level of methylxanthine.

CPAP is delivered with nasal prongs, a nasal mask, or a face mask with 3-6 cm of water pressure.

CPAP effectively treats mixed and obstructive apnea, but it has little or no effect on central apnea. This limitation suggests that CPAP may reduce the frequency of apnea by means of several mechanisms, including stabilization of the partial pressure of O2 (PaO2) by increasing the functional residual capacity (FRC), by altering the influence of stretch receptors on respiratory timing, or by splinting the upper airway in an open position.

Discharge considerations

Apnea-free interval before discharge

Most neonatologists agree that babies should be apnea-free for 2-10 days before discharge. However, the interval between the last apneic event and a safe time for discharge is not clearly established. The minimum apnea-free period is debated among clinicians. Darnall et al concluded that otherwise healthy preterm neonates continue to have periods of apnea separated by as many as 8 days before the last episode of apnea before discharge. [113] Infants with long intervals between apneic event often have risk factors other than apnea of prematurity (AOP).

Home monitoring

Home monitoring after discharge is necessary for infants whose apneic episodes continue despite the administration of methylxanthine. Infants undergoing methylxanthine therapy rarely are sent home without a monitor because apnea may recur after they outgrow their therapeutic level. Without a monitor, caregivers may not know when apnea reappears.

Some families cannot manage monitoring in the home. In these cases, the administration of caffeine may be the only possible therapy. Infants in this situation need frequent follow-up visits, and they should be readmitted for further evaluation when their blood levels approach the subtherapeutic range.

Immunization

Premature infants often have apnea and bradycardia events following the first series of immunizations, and neonatologists caring for premature infants prefer to give immunization while the child remains in the NICU, if the infant is near discharge. These events are less likely to recur during subsequent immunizations; however, prospective studies are required in this regard. [114]

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Long-Term Monitoring

Home monitoring

Various agencies and organizations have stated that home monitoring cannot prevent sudden infant death syndrome (SIDS), also called crib death or cot death, in preterm infants who have apnea of prematurity during their hospitalization. [9]  There is no data to suggest that home monitoring can prevent SIDS in preterm infants with the diagnosis of apnea of prematurity. [65]

Indications for home monitoring

Home monitoring may be indicated in the situations described below.

  • Historical evidence suggests the occurrence of clinically significant apnea or an apparent life-threatening event (ALTE).

  • Recording monitoring or multichannel evaluation documents apnea.

  • The patient has gastroesophageal reflux (GER) with apnea.

  • A sibling or twin of the patient died from SIDS or another postneonatal cause of death (see Special Concerns).

The National Institutes of Health (NIH) consensus conference recommends monitoring for the siblings of infants with SIDS, but only after 2 SIDS-related deaths occur in a family. Physicians often begin monitoring after one sibling dies from SIDS; this practice may be related to a fear of litigation should another child in the family die from SIDS. Siblings of patients who died from SIDS are routinely monitored until one month past the patient's age at death.

Monitoring is not indicated to prevent SIDS in infants older than one year, though proponents believe that such monitoring reduces anxiety in the parents of high-risk infants. Opponents of monitoring cite a lack of evidence to show that monitoring reduces the rate of SIDS. They argue that monitors intrude on the family's life and that they are poorly tolerated by the family. [9]

Types of monitors

Several types of cardiorespiratory monitors are available for home use in the United States. The most common type combines impedance pneumography with an assessment of the patient's mean heart rate. The most notable drawback of impedance monitors is their inability to detect obstructive apnea. Newer monitors can minimize false alarms caused by motion artifact.

Standard home monitors detect respiratory signals and heart rates. Electrodes are placed directly on the infant's chest or inside an adjustable belt secured around his or her chest.

Monitoring units should be capable of recording cardiac and respiratory data because this information can help the physician in evaluating the need to stop medication or monitoring. These devices also record compliance with monitor use. The event recorder contains a computer chip that continuously records respiratory and cardiac signals. Normal signals are erased, but any event that deviates from preset parameters activates the monitor to save records of that event, as well as data 15-75 before and 15-75 seconds it. Additional channels are available to record pulse oximetry readings, nasal airflow, and body position (eg, prone vs supine). The records are downloaded within 24 hours after a parent reports an event or after excessive alarms occur.

Many units now have computer modems that instantly transmit data to the physician's office for evaluation. These easily installed devices are especially useful for families who have had problems with events or alarms.

Some devices, such as pulse oximeters, piezo belts, and pressure capsules, have been impractical to use or have had limited applications. Newer technologies and software programs may soon make such oximeters and similar devices more practical than they once were.

All monitoring devices are associated with false alarms, which are alerts without in the absent of a true cardiorespiratory event. False alarms worry parents. If they happen often, they may discourage use of the monitor. Excessive false alarms can usually be minimized by adjusting the placement of the electrodes and by educating the parents.

Details of monitoring depend on the frequency of events observed during neonatal hospitalization, the size and stability of the infant at the time of discharge, and the degree of parental anxiety.

Follow-up of home monitoring and patient education

Careful follow-up is needed with all cases of home monitoring in prematurely born neonates. Physicians who have limited experience with home monitoring or who cannot interpret the downloaded recordings should seek assistance from a center or program with expertise in these areas.

The most important issue with monitoring is that Neonatal Resuscitation Program (NRP) instructors should educate parents, guardians, and other caregivers about neonatal resuscitation by using a mannequin before their child is discharged from the NICU.

Parents should also be educated about prenatal and postnatal factors associated with an increased risk of SIDS, namely, the following [25, 115] :

  • Prenatal and postnatal tobacco use

  • Opiate abuse during pregnancy

  • Baby's prone sleeping position

  • Pacifier use

  • Use of soft bedding

  • Shared sleeping with children and adults

  • Illnesses in infants with bronchopulmonary dysplasia

  • Genetic factors

Parents must also be aware that postural skull deformities have occurred after the AAP offered positioning recommendations in its Back to Sleep campaign. [116] Prematurely born infants are probably at increased risk. Ways to avoid or minimize skull deformities should be discussed with parents.

Parents of infants with home monitors must have a clearly designated person who they can contact on a regular basis and during emergencies. Many programs or centers provide 24-hour assistance for families of children with home monitors.

The mean duration of home monitoring for prematurely born neonates is often more than 6 weeks. Extended monitoring is reserved for infants whose recordings show notable cardiorespiratory abnormalities. Monitoring beyond age 1 year is uncommon. Most often, children who require such monitoring have other conditions that require the use of additional technology. An example is an infant with bronchopulmonary dysplasia who requires mechanical ventilation at home.

For infants who require therapy with a methylxanthine, drug therapy is typically stopped after 8 weeks without true events, but monitoring is continued for an additional 4 weeks. [117, 118] If no events are noted in this period, monitoring can be discontinued. These recommendations regarding discontinuing methylxanthines or home monitoring are not based on data from controlled studies; these investigations are badly needed.

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