APNEA,

1
APNEA,
ALTE,
and SIDS
Valerie Vickers, RNC, BSN Previous Apnea
Program Coordinator
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OBJECTIVES

• At the completion of this talk, the learner will
  be able to
• Define apnea
• Name the most common form of apnea in the
  premature infant
• Distinguish three conditions of an infant that
  may cause apnea
• Recognize two characteristics of an apparent life
  threatening event (ALTE)
• Identify an evidenced-based intervention for the
  prevention of sudden infant death syndrome (SIDS)

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APNEA is a nonspecific indicator of distress

• Failure of a system
• Early indicator of deterioration

Many known causes of apnea can be diagnosed and
treated.
4
PERIODIC BREATHING

• Thought to be benign
• PB ? Apnea ? SIDS???

These should not be considered linear events.

They overlap but one is not causative to the next.
Definition of Periodic Breathing
3 or more pauses for greater than 30
seconds duration with less than 20 seconds of
respiration between pauses.
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APNEA Cessation of respiratory airflow

• CENTRAL (40-45)
• No respiratory effort, no nasal airflow
• Developmental phenomenon

• OBSTRUCTIVE (10-15)
• ? respiratory effort, no nasal airflow, ? HR
• Caused by aspiration, laryngospasm or poor airway
  control

• MIXED (40-45)
• Both obstructive and central

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Reflex Effects of APNEA

• sinus bradycardia
• drop in blood pressure
• change in cerebral blood flow

Apnea and periodic breathing are common in
premature infants after the first 24 to 48 hours
of life. Premature infants sleep 80 of the
time, term infants 50. Apnea only occurs with
active sleep.
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Factors contributing to decreased inspiratory
effort

• CNS immaturity - ? of synaptic connections ? ?
  sensitivity to CO2
• ? activity of protective respiratory reflexes
  (conserve, rather than breath)
• ? minute ventilation
• diaphragmatic fatigue
• soft compliant chest

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THEREFORE

• Mixed apnea occurs frequently in premature
  infants due to
• increased CNS immaturity
  (central apnea)
• softer chest, weaker diaphragms (obstructive
  apnea)

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PATHOLOGIC APNEA

• Apnea gt 20 seconds with cyanosis, abrupt, marked
  pallor or hypotonia, or bradycardia lt 100 bpm

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APNEA OF PREMATURITY (AOP)
AOP is probably caused by abnormality in the
central control for breathing
Decreased inspiratory effort and blunted
response to CO2 and O2 plus prolonged brainstem
conduction times result in hypoventilation and
hypercarbia

• Developmental characteristics are the primary
  cause due to poor development of both CNS and
  airway control
• Most common form of apnea in premies
• Diagnosis of exclusion
• Usually resolves by 37 weeks post conception but
  occasionally persists for several weeks past term

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Apnea is Associated with Many Clinical Conditions

• Intraventricular bleed
• May see hypoventilation, apnea or respiratory
  arrest

• Subtle seizures
• Along with fluttering eyelids, drooling or
  sucking, tonic posturing

• Sepsis
• Bacterial (GBS, staph. Proteus, Listeria,
  Coliforms
• Viral (RSV, paraflu, herpes, CMV
• Chlamydial
• NEC

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• Congestive Heart Failure
• PDA and CHD
• Due to decreased lung compliance
• Respiratory muscle fatigue
• Chest wall distortion
• Hypoxemia

• Respiratory Distress Syndrome
• Due to atelectasis, ? work of breathing, fatigue
• May lead to chronic lung disease

• Anemia
• oxygen carrying capacity of blood ?
• Arterial pressure perfusing CNS ?

• Polycythemia
• ? blood viscosity and ? blood flow to CNS
• begins at 2-4 hours of age

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• High temperature of environment

• Feeding problems
• overdistention of stomach
• aspiration
• GER (gastroesphogeal reflux) with or without
  aspirations
• due to laryngospasm
• stimulation of irritant receptors in lower
  esophagus causing reflux apnea
• some reflux is common (laundry issue only?)

• Metabolic conditions
• Hypoglycemia
• Hypocalcemia
• Hypernatremia
• Alkalosis

• Others
• Myelomeningocele
• Meningitis

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TREATMENT OF APNEA

• Dependent on Etiology
• Least invasive
• Treat underlying causes
• Non-pharmacologic vs pharmacologic

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TREATMENT OF APNEA NON-PHARMACOLOGIC

• Tactile stimulation
• ? neutral ambient temperature
• Address feeding issues / GER
• Oxygen
• Mechanical CPAP / ventilation
• CPAP markedly reduces apneic episodes with an
  obstructive component
• Improves patency of upper airway by activation of
  dilator muscles or by passive splinting

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TREATMENT OF APNEA PHARMACOLOGIC

• May treat more severe AOP with methylxanthines.
• Methylxanthines effect neurotransmitters and
  increase the transmission of impulses across
  nerves and synapses.

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METHYLXANTHINES

• CAFFEINE
• 2.5 - 5 mg /kg / day once per day (therapeutic
  range 8-15 mcg/ml)
• THEOPHYLLINE
• 3-6 mg/kg/day divided in 2 doses per day
• (therapeutic range 6-12 mcg/ml)

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METHYLYXANTHINES (cont.)

• Caffeine is often preferable
• More centrally active
• Not metabolized by the liver
• However - many pharmacies do not carry it

• Methylxanthines can exacerbate GER - use the
  right drug for treatment

NOTE Neither drug has had controlled study for
efficacy
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ALTE

• APPARENT LIFE THREATENING EVENT
• Frightening event to the observer
• Combination of apnea
• Color change
• Marked change in muscle tone
• Over 37 weeks conceptual age

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Careful Evaluation of EpisodeIndicators for Type
of Treatment

• Obtain accurate report including feeding and
  sleeping history
• Physical exam, vital signs
• Temperature of isolette
• CBC, lytes, ABGs, pulse ox
• Blood and viral cultures
• Chest xray
• Cranial ultrasound
• Echocardiogram
• pH probe, barium swallow
• Placement of feeding tubes (OG/NG)
• Computer monitor reports if available
• Sleep study

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GOAL FOR HOME
Goal is to discharge without methylxanthines or
monitor

• For AOP/Apnea
• No apneic events for 5 days
• If discharge on methylxanthines, standard in this
  community is also discharge with monitor
• May discharge with monitor only if no other
  treatment indicated
• For ALTE
• May discharge sooner than 5 days if work-up
  negative and no events

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HOME MONITORS

• At Risk Group
• Infants with BW less than 1000 grams
• Infants with continued apnea and bradycardia
• Infants requiring methylxanthines to control
  apnea
• Infants with severe gastroesophageal reflux
• Infants with tracheostomies or technology
  dependent
• Less risk but for familys peace of mind
• Infants with severe BPD requiring oxygen
• SIDS sibling or twin of SIDS
• Infants with non-repeated ALTE, no cause found

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CRITERIA FOR SUCCESS OF HOME MONITORING

• Training is crucial!
• Apnea class including CPR
• Caregivers have adequate time to use equipment
  prior to discharge
• Support is imperative!
• Support system includes medical, technical,
  psychosocial, community support
• Choose the right monitor!

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TERMINATION OF MONITOR USE

• AAP says by 43 weeks post conception or
  cessation of extreme events
• No significant apnea or repeat of ALTE event for
  1-2 months
• If on methylxanthines, 1-2 weeks after
  discontinuation of medications with no
  significant apnea
• Resolution of primary problem

MONITORING CANNOT GUARANTEE SURVIVAL
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MONITORS

• Monitors heart rate and respirations
• Common settings Low HR 70 bpm for premie, 60 for
  term high HR off apnea delay 20 seconds
• Has a memory, can be printed/analyzed
• ON/OFF switch child-proof, sometimes nurse proof
  ?
• Belt must be tight pad touches skin always
• Clean pads with water only

Parents are the best monitor use only when the
baby is not observed.
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SUDDEN INFANT DEATH SYNDROME (SIDS)

• Sudden death of any infant or young child which
  is unexplained by history and in which a thorough
  post mortem fails to demonstrate and adequate
  cause of death.

Definition taken from the NIH Consensus
Development Conference on Infantile Apnea and
Home Monitoring
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SIDS STATISTICS

• Currently, 0.5 death per 1000
• 1.2 deaths per 1000 live births per year 1992
• Back to Sleep campaign in the US
• 1994 endorsed side or supine
• 1996 endorsed supine only
• 0.6 deaths per 1000 in 20

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SIDS STATISTICS

• Ranked 3rd in cause of death in infants older
  than one month
• Congenital anomalies is 1st
• Prematurity or low birth weight is 2nd
• Most common age for SIDS is 2-4 months
• 99 of deaths before 6 months
• 1 of deaths 6-12 months
• extremely rare in the 1st month of life
• infants have a change in response to hypoxia
  around 6 months of age

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SIDS FACTS

• SIDS risk for an infant with AOP or who has had
  an ALTE is at no greater risk than the general
  population
• Premature infants have a slightly greater risk
  which increases as their gestational age
  decreases
• Home monitoring of infants has NOT decreased the
  incidence of SIDS
• The SIDS sibling is not at greater risk of SIDS
  than the general population

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SIDS RESEARCH

• Research findings
• Supine sleeping position most protective, side
  lying better than prone but not protective as
  supine
• Overheating contributory
• Smoking contributory
• Any breastfeeding is protective
• Pacifier use is protective
• Sleeping in the same place every night is
  protective
• Research indicates SIDS is a malfunction in
  arousal
• CHIME study indicates that normal infants have
  apnea, bradycardia and desaturations into the
  70s (question then is why they can recover and
  the infant who dies of SIDS does not)

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SIDS RESEARCH CONCLUSIONS
Research indicates that SIDS is more complex
than a single abnormality in a single system.

• According to the triple-risk hypothesis, SIDS
  occurs when three events happen to an infant
  simultaneously
• an underlying vulnerability in homeostatic
  control,
• a critical developmental period in state-related
  homeostatic control
• an exogenous stressor(s) that exacerbates the
  infants underlying vulnerability

National Institute of Child Health Human
Development (NICHD)
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SIDS PHYSIOLOGICAL CHARATERISTICS

• tachycardia then bradycardia prior to fatal
  event
• not necessarily proceeded by apneic
  event
• diminished of breathing pauses
• ? heart rate variation related to respirations
• profuse sweating

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SIDS PREVENTION

• Failure of arousal mechanism
• Ethnicity is a factor
• Back to Sleep campaign
• AAP continues to discourage the use
  monitors in its 2005 policy statement
• includes recommendations regarding pacifier use
  and sleep environments, some of which is
  controversial
• Pediatrics Vol 116, No. 5, November 2005
• AWHOON website http//www.awhonn.org/awhonn/?pg87
  3-8010-18770