Chapter 3 Apnea
PATHOPHYSIOLOGY
Apnea is the cessation of respiration for more than 20 seconds with or without cyanosis, hypotonia, or bradycardia. Apnea may be a symptom of another disorder that resolves when the latter is treated. Such disorders may include infection, gastroesophageal reflux, hypoglycemia, metabolic disorders, drug toxicity, or hydrocephalus, or thermal instability in newborns. Central apnea is a respiratory pause, the cause of which is related to the failure of the excitatory mechanisms to function properly in the respiratory center in the brain. Immaturity of the central nervous system frequently accounts for apnea of the newborn, which occurs most frequently during active sleep. Obstructive apnea occurs when an obstruction of the airway exists, usually at the level of the pharynx, and occurs most frequently during sleep. Here, there is continuation of respiratory effort without air flow in the airway because of the obstruction. This condition may be due to enlarged tonsils and adenoids, congenital disorders such as Pierre Robin syndrome, or muscular hypotonia. Apnea consisting of both central and obstructive components is mixed apnea. Apnea can also occur in premature infants during certain normal activities, such as feeding.
INCIDENCE
1. More than 50% of infants weighing less than 1.5 kg require treatment for recurrent prolonged apneic episodes.
2. About one third of infants born at less than 32 weeks’ gestation have apneic episodes.
3. Idiopathic apnea rarely occurs in term infants.
4. The prevalence of obstructive sleep apnea is estimated at 1% to 3% of preschool- and school-aged children. Obstructive apnea is most often caused by hypertrophy of the adenoids and tonsils.
LABORATORY AND DIAGNOSTIC TESTS
1. Polysomnography—a sleep study that includes direct observation of the patient along with electroencephalogram (EEG), blood pressure, breathing rate, heart rhythm, oxygen saturation, eye movement, and electrical activity of muscles. Used to determine if apnea is central, obstructive, or mixed.
2. Apnea monitoring—used to monitor the frequency and duration of apneic episodes.
3. Pulse oximetry—used to assess for associated oxygen desaturation.
MEDICAL MANAGEMENT
Infants with suspected or documented apnea are monitored using either a cardiorespiratory or an apnea monitor. The immediate management of an apneic episode is to provide gentle stimulation by rubbing the child’s back or feet. Do not shake infant or child vigorously to stimulate the infant. If the infant or child does not respond, the airway should be opened, and cardiopulmonary resuscitation (CPR) should be initiated. If apnea is a symptom of another disorder, the treatment of that disorder should result in the elimination of apnea.
The management of central apnea, most frequently seen in premature infants, includes minimizing potential causes such as temperature variances and feeding intolerance. Xanthine medications such as caffeine and theophylline provide central nervous system stimulation. Pulmonary function support may include the use of supplemental oxygen and continuous positive airway pressure (CPAP) at low pressures. Indications for home apnea monitoring in newborns with apnea include a history of severe apneic episodes, documentation of apnea during polysomnography, severe feeding difficulties with apnea and bradycardia, and sibling relationship with a victim of SIDS.
The management of obstructive apnea may include the use of specific positioning techniques, the use of CPAP or inspiratory and expiratory positive airway pressure (BiPAP), tracheostomy to bypass the area of obstruction, or adenotonsillectomy. Aggressive surgical management to widen the caliber of the trachea has eliminated the need for tracheostomy in some cases.
NURSING INTERVENTIONS
1. Perform routine monitoring of heart rate and respiratory rate in preterm infants.
2. Gently rub infant’s back or feet, which will stop some apneic episodes if they are caught early.
3. Allow parents to verbalize feelings.
4. Provide instruction on all equipment to be used by parents, such as apnea monitor or BiPAP unit.
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Goldstein NA, et al. Clinical assessment of pediatric obstructive sleep apnea. Pediatrics. 2004;114(1):33.
Hockenberry MJ, et al. Wong’s nursing care of infants and children, ed 7. St. Louis: Mosby, 2004.
Kenner C, et al. Comprehensive neonatal nursing, ed 3. St. Louis: Mosby, 2002.
Stokowski LA. A primer on apnea of prematurity. Adv Neonatal Care. 2005;5(3):155.
