Pediatric Sleep Scoring Issues Patrick Sorenson, MA, RPSGT

Infant & Pediatric Scoring

April, 2011

NESS

Newport, RI

Staging Section

Newborn: Sleep-Wake Cycles

Ultradian

A newborn spends approx. 70% of every 24 hrs in sleep.

Cycles last about 40-60 minutes

Feedings occur about every 3-4 hours-use demand not schedules.

Quietsleep

ActiveSleep

Awake

REM/NREM Developmental

Distributions

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

Premies Infants Toddlers Teens Adults

REM

NREM

Quiet Sleep (QS, Stage N)

Quiet sleep is analogous to NREM sleep• EEG - characterized by high amplitude (14 to 35

µV), slow wave (0.5-5 Hz) patterns. • Trace’ Alternant patterns consist of 2 to 6

second bursts of high amplitude slow waves separated by 4 to 8 seconds of low-voltage mixed activity. TA appears by about 28 weeks GA, becomes associated with QS by ~32 weeks. TA appears in its mature form by ~36 weeks.

Quiet Sleep-EEG findings, cont.

• Sleep spindles appear by ~4 weeks and develop rapidly through 8 weeks of age and clearly characterize NREM sleep by 3 months of age. – Coincidental with the social smile.

• K-complexes first appear at ~4-6 months and are fully developed by about 2 years of age.

Quiet Sleep-Physiological Findings

• Slower cardiac rhythm as compared to Active Sleep

• Slower respiratory rates

• Resting levels of muscle tone

Active Sleep (AS, Stage R)

Active Sleep is analogous to REM sleep• EEG is characterized by low-voltage fast

desynchronous activity w/bilaterally synchronous REM’s.

• Variable frequency ranges from 14-35 µV (usually in the 20-30 µV range).

Active Sleep (Stage R) -Physiological Findings

• Increased or variable cardiac rate• Increased or variable respiratory rate;

primarily costal in nature• Out-of-phase chest and abdominal effort

channels. Inhibition of muscle tone in infant’s chest wall musculature.

• Frequent brief movements, grimaces, peeking, vocalizations, grunts, sucking, tremors & squirming are all common in AS.

Esophageal pH• Ability to interface pH equipment with

polygraph and slow-chart writer• Examine the relationship between GER

and apnea • GER is most commonly seen during

fussy wakefulness• Document all feeds, meds and GER

episodes

2007 AASM Rules for Staging Children

• Pediatric sleep scoring rules start at 2 months post-term

• Same terminology as adults with addition of NREM (N) as depending upon features seen.

• N = Ø K’s, spindles or high amp slow-wave (0.5-2 Hz)• N2 = presence of K’s and spindles• Once N2 & N3 features are present, begin scoring as

older child/adult – N1, N2, N3 & R.• Usually 5-6 months PT, but sometimes as young as

4-4.5 months.

2007 AASM Rules for Staging Children – Dominant Posterior Rhythm (DPR)

• DPR changes with age– 3.5-4.5 Hz 3-4 months PT– 5-6 Hz by 5-6 months PT– 7.5-9.5 Hz by 3 years.

• Amplitude also changes• Still score sleep onset if DPR ≤

50% of the epoch• Eye movements are key!

Incidence of sleep terrors

• Confusional arousals seen in about 5-10% of all children, though regular nighttime awakenings are seen in 50-70% of children 2-10 years old.

• Occur in about 3% of prepubertal children and less than 1% of adults.

• Onset of symptoms is about 2-4 years. Can occur at any age.

• General sleep architecture w/vulnerable transition periods.

1 2 3 4 5 6 7 8

Hour

?

W

1

REMREM2

3

4

Begin Respiratory Section

Sleep Foundations 27

The “How to”• Sensor used to detect absence of airflow for identification of an apnea is an

oronasal thermal sensor

• Sensor for detection of airflow for identification of a hypopnea is a nasal air pressure transducer without the square root transformation of the signal

• Acceptable sensors for detection of respiratory effort are either esophageal manometry, or calibrated or uncalibrated inductance plethysmography

• Sensor for detection of blood oxygen is pulse oximetry with a maximum acceptable signal averaging time of 3 seconds

• Acceptable methods for assessing alveolar hypoventilation are either transcutaneous or end-tidal CO2 monitoring

OxygenationSensors

• Pulse oximetry

• < 3 seconds averaging time

• Pulsewave = plethysmograph

Nasal pressure in children• Need:

– More than one airflow measure.

– Way of simultaneously measuring PCO2.

Dual PN / CO2 system (commercial)

Sleep Foundations 31

Age Criteria

• Criteria for respiratory events during sleep for infants and children can be used for children <18 years, but an individual sleep specialist can choose to score children ≥ 13 years using adult criteria.

Normative data ages 1-17 y

0

1

2

3

4

5

6

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Marcus, Am Rev Respir Dis 1992; 146:1235

Age (y)

N

Results

• Obstructive AI = 0.1 + 0.5 / hr

• Obstructive AHI = 0.2 + 0.6 / hr*

*Witmans, AJRCCM 2003; 168:1540

Normative data ages 1-15 y

Uliel, Chest 2004; 125:872

Results

• Mean obstructive AI = 0 / hr

• Mean obstructive AHI = 0 / hr

Sleep Foundations 36

The RulesScore a respiratory event as an obstructive apneaobstructive apnea if it meets all of the

following criteria:

• Event lasts for at least 2 breaths (or the duration of 2 breaths as determined by baseline breathing pattern)

• Event is associated with a >90% fall in the signal amplitude for ≥ 90% of the entire respiratory event compared to the pre-event baseline amplitude

• Event is associated with continued or increased inspiratory effort throughout the entire period of decreased airflow

• Duration of the apnea is measured from the end of the of the last normal breath to the beginning of the first breath that achieves the pre-event baseline inspiratory excursion

Obstructive apneaDefinition

MEETS ALL OF THE FOLLOWING:

• > 2 missed breaths

• > 90% fall in flow amplitude

• No arousal / SaO2 criteria

Sleep Foundations 39

Mixed Events?

Score a respiratory event as a mixed mixed apneaapnea if it meets both duration and

flow amplitude criteria, and it is associated with absent inspiratory

effort in the initial portion of the event, followed by resumption of

inspiratory effort before the end of the event

Sleep Foundations 40

Central EventsScore a respiratory event as a central apneacentral apnea if it is

associated with absent inspiratory effort throughout the entire duration of the event and one of the

following is met:

• Event lasts 20 seconds or longer

• Event lasts at least 2 missed breaths (or the duration of 2 breaths as determined by baseline breathing pattern) and is associated with an arousal, an awakening or a ≥ 3% desaturation

Central Event

Central Apnea > 20 sec(Infants)

Age (weeks)

0 2 4 6 8 10 12 14 16 18 20

Dur

atio

n of

apn

ea (

sec)

16

20

24

28

32

36

40

Hunt, Pediatr Res 1996; 39:216

Infant CA, cont.• Apnea of Prematurity: Slowed or retarded

maturation of the Arcuate Nucleus and Carotid Chemoreceptors can inhibit natural respiratory drive mechanisms

• Central Apnea commonly follow sighs as the drive to breathe is temporarily inhibited

• Periodic Breathing consists of central pauses of 3 or more seconds followed by normal breathing for up to 20 seconds

Infant CA, cont.• Periodic Breathing is most prevalent in

premature infants and is usually separated by bursts of 2-4 quick breaths between complete respiratory drive inhibition

• By 3 months, normal PB consists of < 3% of total sleep time

• Respiratory drive seems to be reset at birth

Apnea of PrematurityCan worsen with:• Anemia-below normal reduction of

erythrocytes in the quantity of hemoglobin.• Septicemia-pathogenic microorganisms or

their toxins are present in the blood.• Hypoxia-reduced O2 supply to tissue.• GER-Gastroesophageal Reflux.• Seizures-electrical disturbance of the CNS.

Sleep Foundations 46

Pediatric Hypopnea RulesScore a respiratory event as a HypopneaHypopnea if it meets all of the following criteria:

• Event is associated with a ≥ 50% fall in the amplitude of a nasal pressure or alternative signal compared to the pre-event baseline excursion

• Event lasts at least 2 missed breaths (or the duration of 2 breaths as determined by baseline breathing pattern) from the end of the last normal breathing amplitude

• The fall in the nasal pressure signal amplitude must last for ≥ 90% of the entire respiratory event compared to the signal amplitude preceding the event

• Event is associated with an arousal, awakening or ≥ 3% desaturation

HypopneaDefinition

• MEETS ALL OF THE FOLLOWING:

• > 2 missed breaths• > 50% fall in amplitude• Arousal / awakening / > 3%

desaturation

Sleep Foundations 48

RERA’sScore Respiratory Effort Related Arousal (RERA)Respiratory Effort Related Arousal (RERA) if conditions below are met:

• When using a nasal pressure sensor all of the following must be met: Discernable fall in the amplitude of signal from a nasal pressure

sensor, but it is less than 50% in comparison to the baseline level

Flattening of the nasal pressure waveform

Event accompanied by snoring, noisy breathing, elevation in the end-tidal PCO2, transcutaneous PCO2, or visual evidence of increased work of breathing

Duration of event is at least 2 breath cycles (or the duration of 2 breaths as determined by baseline)

RERA definition (PN)

• MEETS ALL OF THE FOLLOWING:

• < 50% fall in amplitude

• Flattened waveform

• > 2 breaths

• Snoring, WOB, CO2

Sleep Foundations 50

Use of Pes for RERAWhen using an Esophageal Pressure Sensor (Pes)Esophageal Pressure Sensor (Pes) all of the

following must be met: There is a progressive increase in inspiratory effort during

the event

Event is accompanied by snoring, noisy breathing, elevation in the end-tidal PCO2, transcutaneous PCO2 or visual evidence of increased work of breathing

Duration of the event is at least 2 breath cycles (or the duration of 2 breaths as determined by baseline breathing pattern)

RERA definition (Pes)

MEETS ALL OF THE FOLLOWING:

• Progressive increase in inspiratory effort

• > 2 breaths

• Snoring, WOB, CO2

Child with UARS

FlowChestAbdo

Pes

**

** **

Sleep Foundations 53

Hypoventilation Rule

Score the presence of sleep-related hypoventilation when

>25% of the total sleep time as measured by either the

transcutaneous PCO2 and/or tidal CO2 sensor(s) is spent with a CO2

>50 mm Hg.

Noninvasive CO2 measurements

• Moderate to high correlations between transcutaneous / end-tidal and arterial CO2.

• Largest discrepancies occur in hypercapnic subjects or subjects with respiratory disease.

• End-tidal CO2 tends to underestimate arterial CO2.

• Transcutaneous CO2 tends to have a smaller bias then end-tidal PCO2, with a tendency for overestimating CO2.

ETCO2 Waveform

The capnograph trace

•1. Inspiratory baseline •2. Expiratory upstroke •3. Expiratory plateau •4. Inspiratory downstroke

ETCO2 is range-based.

Individual values are of little use.Torr & mm/Hg mean the same thing

End-tidal measurements• Breath-by-breath changes• Need good waveform with

plateau• Uncomfortable• Poor signal:

– Mouth-breathing– Secretions– Tachypnea, small lung volumes

Transcutaneous measurements

• Slow response rate• Well tolerated• Problems:

– Burns – Required repositioning every 4 hours

– Poor perfusion– Skin lesions

Sleep Foundations 61

Periodic Breathing Rule

Score Periodic BreathingPeriodic Breathing if there are: >3 episodes of central apnea lasting > 3 seconds separated by

no more than 20 seconds of normal breathing

Sudden Infant Death Syndrome (SIDS)

The sudden and unexpected death of an infant for which sufficient cause cannot be found by a death scene

investigation, review of the history, and a postmortem examination.

Respiratory Drive Chart

0%10%20%30%40%50%60%70%80%90%

100%

Birth-FT 1 week 2 weeks 3 weeks 1 month

Thermoregulation

Chemoreception

This graph shows the rate per 1,000 live births for infant deaths during the neonatal period (between the ages of birth through 27 days) in the United States.

PSG night-to-night variability(sleep architecture)

0

20

40

60

80

100

SleepEfficiency

REM Arousal Index

Night 1

Night 2

(%)(% TST) (N/hr)

Katz, J Pediatr 2002; 140:589

PSG variability(respiratory)

0

20

40

60

80

100

AHI Hypoventilation

Night 1

Night 2

(%) (% TST)(N/hr)SaO2 Nadir

Katz, J Pediatr 2002; 140:589

Reliability of infant respiratory scoring

• Scoring of apnea

• Based on RIP

• = 0.65

• After training: = 0.85

Corwin, Pediatr Res 1998; 44:682

Summary

• Most scoring is similar to former ATS pediatric criteria.

• Established the 1st criteria for pediatric hypopnea scoring.

Major differences between pediatric and adult scoring

• CA scoring: > 20 seconds OR associated abnormalities.

• Obstructive events: > 2 breaths.

• CO2 usually measured.

Time for questions?

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