Apparent Life-threatening Events in Presumed Healthy Neonates During the First Three Days of Life

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ABSTRACT.

Objective. To study the historical, clinical,

and pneumographic correlates of apparent life-threaten ing events (ALTEs) in a term newborn nursery popula tion during the first 3 days of life in a maternity hospital.

Methods. Twenty newborns with ALTEs during the

first 3 days of life were studied.

Family, antenatal,

and

intrapartum histories were reviewed. Diagnostic and therapeutic data surrounding the ALTEs were docu mented. Multichannel recordings performed after the ALTEs occurred were analyzed. Hospital discharge dis

positions

and postdischarge

outcomes were reviewed.

Results. Of approximately 15 000 deliveries during a

three-year period, 20 infants had ALTEs. Apnea was the

most common presenting

symptom, and cyanosis usually

accompanied the event. Tactile stimulation and oxygen were the most frequent acute treatments, with airway clearance, intermittent positive pressure ventilation, and cardiac massage less common. Forty percent of the events had potentially identifiable causes, including central ner vous system abnormality, airway obstruction, or a persis tent fetal cardiovascular shunt. Of the initial multichan nel recordings, 11 had desaturation of less than 85%, 10 had apneic pauses of greater than 15 seconds, and 4 had

bradycardia

of less than 80 beats per minute.

Eighteen

infants were discharged and received home monitors; 4 received medication. ALTEs recurred in 4 infants before discharge and in 1 after discharge. No deaths occurred.

Conclusions. (1) ALTEs do occur in the early newborn

period in a low-risk term group; (2) causes are unknown in the majority of cases; (3) multichannel recordings may have abnormalities; and (4) the likelihood of recurrent ALTEs is greater during the first week than during the

next 2 months. Pediatrics 1996;97:349â€”351;apparent life

threatening events, newborn, apnea, cyanosis, bradycar

dia.

ABBREVIATIONS. SIDS, sudden infant death syndrome; ALTE,

apparent life-threatening event; ENSD, early neonatal sudden

death.

There

has been

limited

information

in the litera

lure about sudden

infant death syndrome

(SIDS) and

apparent

life-threatening

events

(ALTEs)

in mature

neonates

during

the first few days of life. SIDS has

been

reported

to occur

during

the first 2 weeks

of

life, with

between

1% and

3% of all cases

during

infancy

occurring

during

that

early

time

frame.@3

From the Department of Neonatology, Columbia Hospital For Women,

Washington, DC.

Received for publication Jun 13, 1994; accepted Apr 14, 1995.

Reprint requests to (L.J.G.) Department of Neonatology, Columbia Hospital For Women, 2425 L St NW, Washington, DC 20037.

emy of Pediatrics.

There have been two case series in the literature

that

discussed

term newborns

who had ALTEs in mater

nity hospitals.4'@

The goals of the present

study

were to define

the

incidence

of ALTEs

in a presumably

healthy

term

newborn

nursery

population,

to evaluate

contribu

tory prenatal

and perinatal

factors,

to describe

acute

diagnostic

and therapeutic

circumstances,

to present

pneumographic

analyses,

and

to summarize

dis

charge

dispositions

and follow-up

outcomes.

METHODS

An ALTE has been defined by the National Institutes of Health

Consensus Development Conference on Infantile Apnea and Mon

itoring as an episode that is â€œ¿frighteningto the observer and

characterized by some combination of apnea, color change, change

in muscle tone, choking or gagging.â€•6 Twenty patients with

ALTEs were evaluated during a 3-year period from a delivery

population of approximately 15 000 births. Family histories were unremarkable for ALTEs, SIDS, or disorders of cardiorespiratory

control. Five of 20 infants had 1-minute Apgar scores of less than

7, and I infant had a 5-minuteApgar scoreof lessthan 7. Ante

partum medications received by the mothers other than epidural

analgesia included nalbuphine in five cases, ranging from 1 to 11

hours before delivery. Of the mothers who breastfed, 4 received

postpartum medications, including 2 with epidural opioids and 2

with parenteral analgesics. Fifteen infants were breastfed, 3 were

formula fed, and 2 received both. Prevailing breastfeeding rates

during the study period varied between 60% and 70%.

Multichannel electronic recordings were performed in all cases,

twice in two cases. The initial studies were all done during the first

week of life, between I and 5 days after the ALTEs. Sixteen were

five-channel trend studies of 10 to 12 hours' duration (heart rate,

pulse, peripheral oxygen saturation, thoracic impedance, and na

sal air flow), and two were without air flow measurements. Elec

trocardiographic printouts were also available as needed. Two

event studies of 2 to 3 days' duration were done. A Healthdyne

(Marietta, GA) recorder, thermistor, and printer were used. The

heart rate was averaged on an eight-beat-interval basis. Validated

Nelcor (Hayward, CA) oximeters were used for all the trend

studies, with oxygen saturations based on 5- to 7-second averag

ing intervals. A validated Healthdyne oximeter was used for the

event studies, with oxygen saturation based on a four-pulse inter

val. In all cases, heart rate trend and pulse measurements were

examined simultaneously to assure the veracity of oxygen satura tion findings. These recordings were scored manually by the same

individual in all cases. A prolonged apneic pause was defined as

lasting for more than 15 seconds. Bradycardia was defined as less

than 80 beats per minute for more than 5 seconds, and desatura

tion was defined as less than 85% for more than 5 seconds. Apneas

were judged as central, obstructive, or mixed based on the pres

ence or absence of air flow in relation to impedance. An apnea

hypopnea sequence was defined as a contiguous sequence of

apnea and hypopnea, with the latter read as impedance waves at

less than a 50% amplitude of the patient's standard.

RESULTS

The salient

diagnostic

and therapeutic

aspects

of

the ALTEs are sunm'iarized

in Table I . Initial events

PEDIATRICS Vol. 97 No. 3 March 1996 349

Apparent

Life-threatening

Events in Presumed

Healthy

Neonates

During

the First Three Days of Life

Lawrence

J. Grylack,

MD and Allie D. Williams,

RN

at Viet Nam:AAP Sponsored on September 1, 2020

www.aappublications.org/news

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350 APPARENT LIFE-THREATENING EVENTS IN HEALTHY NEONATES

TABLE 1. Apparent Life-threatening Events: Clinical

Charac-tenstics of Initial Events

Event Primary Symptoms, n Secondary Symptoms, n

Apnea 15

Cyanosis 5 12

Bradycardia 6

Pallor 3

Hypotonia 2

in the 20 infants took place during the first 3 days of life, including 10 on day 1 and 8 on day 2. The initial events occurred in the regular or transitional nursery settings or the mothers’ rooms and were observed by nurses or parents. Four recurrences took place in the intensive care nursery after the infants were receiv-ing electronic cardiorespiratory monitoring. Four of the initial ALTEs were reported to have occurred during feeding epochs. Gagging or choking was re-ported in conjunction with the initial apnea or cya-nosis in 3 infants. Reliable sleep position data were not available in all cases. However, a change from prone to nonprone as the routine sleeping position took place about midway through the study period in accordance with American Academy of Pediatrics guidelines.7

In response to the initial ALTEs, nurses on duty in the regular or transitional nurseries performed most of the immediate treatment. Further treatment was provided, as needed, by a neonatal intensive care unit physician and nurse in response to pages to respond immediately. Acute therapy for these events is summarized in Table 2. From a causative stand-point, 40% had potential causes for their events. Two infants had suspected airway obstruction based on milk being present in their airways, and clinical and radiologic signs of an aspiration syndrome devel-oped in one of these. This infant subsequently had a diagnosis of gastroesophageal reflux. Three infants had delayed cardiovascular transition diagnosed by a cardiologist based on echocardiographic findings of bidirectional shunting through a patent foramen ovate and/or patent ductus arteriosus. Three infants had neurologic abnormalities based on diagnostic imaging. One had a structural central nervous sys-tern abnormality and seizures; another had periven-tricular leukomalacia; and a third had an intraven-tricular hemorrhage. Of the five infants whose mothers received antepartum nalbuphine analgesia, none had respiratory or neurologic depression in the delivery room. Routine metabolic screening was done in all cases; this did not include organic acid

TABLE 2. Apparent Life-threatening Events: Acute

Treat-ment Given for Initial Event

Treatment n

Tactile stimulation 14

Oxygen Suction 14 6 Intermittent positive-pressure ventilation

4 (1 with endotracheal tube)

Cardiac massage Naloxone

I I

analysis. Six infants were treated with antibiotics empirically, but deep cultures were all negative.

Results of the multichannel recordings are surnrna-rized in Table 3. Of the 10 studies that contained apneic pauses of more than 15 seconds, 2 had two episodes each. Six of these 12 episodes were central apneas, 4 were obstructive, and 2 were mixed. An apnea-hypopnea sequence was noted if accompanied by desaturation and/or bradycardia.

Dispositions for these infants were made by van-ous physicians. Of the 20 infants with ALTEs, 18 were discharged home and received candionespira-tory monitors. Four infants were discharged receiv-ing medication: 2 on aminophylline, I on phenobar-bital, and 1 on hydantomn. Follow-up by report revealed that, within a range of 2 to 24 months, no postdischarge deaths occurred, and one additional ALTE was reported.

DISCUSSION

The term ALTE has replaced the terms near-miss SIDS, aborted SIDS, and aborted crib death partly because of a lack of consensus regarding the relation-ship between ALTEs and SIDS. Nevertheless, reports about ALTEs in the term newborn infant have been presented in the same case series with SIDS. Pol-bergen and Svenningsen4 reported on I 3 cases of “early neonatal sudden death (ENSD)” and “near-missed ENSD” during the first 4 days of life in a population of 26 000 full-term infants during a 5#{189}-year period between 1977 and 1983 in Sweden. Of the 13 cases, resuscitation failed in 3; another 4 died within a few days; and 6 survived. The calculated near-missed ENSD rate was 0.35 per 1000 live births. Burchfield and Rawlings5 described 10 apparently healthy term newborns of whom 5 died unexpect-edly and 5 had ALThs during the first 3#{189}days of life in level I nurseries in Florida in a 1985 through 1990 period. Because the 10 infants were born in five different cities in Florida, the incidence rate of ALTEs could not be established. Similar to the group stud-ied by Polberger and Svenningsen4 and in contrast to the group studied by Burchfield and Rawlings,5 all our infants with ALTEs were inborn at a maternity hospital, allowing us to calculate an incidence rate of approximately I .3 per 1000. No larger surveys exist on this subject.

In the past, ALTEs in the early newborn period have been ascribed to airway obstruction, maternal analgesia or anesthesia, delayed peninatal cardiovas-cular transition, infection, and neurologic abnormal-ities. Of the cases in our series in which potential causes were identified, central nervous system ab-normalities were likely to have preceded the ALTEs.

TABLE 3. Results of Initial Multichannel R ecordings (n = 20)

Median day of life for initial study day 3 Findings

Apnea greater than 15 s 12

16-20s 8

>20s 4

Bradycardia 4

Desaturations II

Apnea and hypopnea 5

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ARTICLES 351

The cases with obstruction were documented during the ALTEs and could have been either precipitating or secondary factors in the events. The cardiovascu-lar abnormalities documented in three cases may have been results instead of causes of the ALTEs, especially because cyanosis was not the primary symptom. Unlike the the study by Polberger and Svenningsen,4 in which sepsis was a putative cause of some newborn ALTEs, none of our infants had documented infection.

In contrast to the two previous studies on newborn ALTEs, multichannel recordings were done in all cases in the current study. There have been reports of recordings done on full-term healthy newborns dur-ing the first week of life who had no abnormal din-ical events. Based on abdominal wall movement, Richards et at8 reported that the mean longest breath-ing pause in a group of 1- to 3-day-old infants was 13.1 (range, 6.0 to 19.2) seconds, and it was 11.1 (range, 7.1 to 21 .6) seconds in a group of 4- to 7-day-old infants. Stein et al9 reported on pneumograms done with thoracic impedance at 3 days of age in healthy term infants. The longest apneic episode re-ported was 7.8 (±4.2) seconds. Recently, Hunt et al,1#{176} using documented event monitoring, reported that the longest apnea in asymptomatic term infants at 0 to 6 days was 17 seconds. Our recorded data of patients with apnea durations of more than 15 sec-onds exceed the high end of the range of the norma-tive group of Stein et al9 and falls either within the upper end or above the normal range in the studies of Richards et al8 and Hunt et al.1#{176}Sasidhara&1 stud-ied permnatally asphyxiated term infants compared with control infants between 3 and 7 days of age using transthoracic impedance without oxygenation or air flow measurements. Of the asphyxiated group, 31 % had apneas of more than 15 seconds compared with none of the control infants. Neither group had bradycardia (less than 80 beats per minute). The presence of an ALTE in our patients may have af-fected the respiratory and/or cardiovascular control systems adversely in some of our patients, thereby accounting for the variances in the recordings. Some studies of infants who had ALTEs beyond the new-born period have shown increased durations of re-spiratory pauses after the ALTEs when compared with age-matched control infants.12

Finally, the use of home monitoring and the risk of SIDS or recurrent ALTE in this group of patients is still controversial. Home monitors were used in most

cases based on individual physician preference. Of the recurrent ALTEs, one of five occurred after dis-charge from the nursery. Of the infants in the previ-ous newborn ALTE studies who subsequently died, all deaths were caused by the initial events or were secondary to the causes of the initial events.4’5

In summary, we conclude that: (1) ALTEs do occur in the early newborn period in a presumably low-risk term group; (2) causes are unknown in a major-ity of cases, but abnormalities of the central nervous system, cardiovascular system, and the gastrointes-tinal tract may be identified in association with these events; (3) multichannel recordings may have abnor-malities; and (4) the likelihood of recurrent ALTEs is greater during the first week than during the next 2 months.

ACKNOWLEDGMENTS

We gratefully acknowledge Erlene Thompson and Yvette Hicks for their secretarial skills in preparing this manuscript.

REFERENCES

1. Beckwith JB. The Sudden Infant Death Syndrome. Rockville, MD: US

Public Health Service Office of Maternal and Child Health; 1976. US Dept of Health, Education and Welfare publication HSA 76-5137 2. Brooks JG. Apnea of infancy and sudden infant death syndrome. Am

Dis Child. 1982;136:1012-1023

3. Fedrich 1. Sudden unexpected death in infants in the Oxford Record

Linkage area: an analysis with respect to time and place. Br I Prey Soc Med. 1973;27:217-224

4. Polberger 5, Svenningsen NW. Early neonatal sudden infant death and near death of full term infants in maternity wards. Acta Paediatr Scand. 1985;74:861-866

5. Burchfield DJ, Rawlings J. Sudden deaths and apparent life-threatening

events in hospitalized neonates presumed to be healthy. Am JDis Child. 1991;145:1319-1322

6. NIH Consensus Development Conference. Infantile Apnea and Home Monitoring. Rockville, MD: US Public Health Service; 1986:4. US Dept of

Health and Human Services, NIH publication 87-2905

7. American Academy of Pediatrics Task Force on Infant Positioning and SIDS. Positioning and SILlS. Pediatrics. 1992;89:l 120-1126

8. RichardsJM, Wilson AJ, Southall DP, AlexanderJR, Shinebourne FA, de Swiet M. Sequential 22-hour profiles of breathing patterns and heart rate in 110 full-term infants during their first 6 months of life. Pediatrics. 1984;74:763-777

9. Stein IM, White A, Kennedy JL, Chernoff H, Gould JB. Apnea record-ings of healthy infants at 40, 44, and 52 weeks postconception. Pediatrics. 1979;63:724-730

10. Hunt CE, Hufford DR. Bourguignon M, Oess A. Cardiorespiratory and oxygen saturation events by documented home monitoring in normal infants. Pediatr Res. 1994;35:231A. Abstract

1 1. Sasidharan P. Breathing pattern abnormalities in full term asphyxiated

newborn infants. Arch Dis Child. 1992;67:440-442

12. Brooks, JG. Apparent life-threatening events and apnea of infancy. Clin Perinatol. 1992;19:809-838

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Lawrence J. Grylack and Allie D. Williams

Three Days of Life

Apparent Life-threatening Events in Presumed Healthy Neonates During the First

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Pediatrics

Lawrence J. Grylack and Allie D. Williams

Three Days of Life

Apparent Life-threatening Events in Presumed Healthy Neonates During the First

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Apparent Life-threatening Events in Presumed Healthy Neonates During the First Three Days of Life

ABSTRACT.

Methods. Twenty newborns with ALTEs during the

first 3 days of life were studied.

Results. Of approximately 15 000 deliveries during a

most common presenting

bradycardia

Conclusions. (1) ALTEs do occur in the early newborn

There

the first 2 weeks

There have been two case series in the literature

factors,

7, and I infant had a 5-minuteApgar scoreof lessthan 7. Ante

RESULTS

J. Grylack,

350 APPARENT LIFE-THREATENING EVENTS IN HEALTHY NEONATES

DISCUSSION

ARTICLES 351

ACKNOWLEDGMENTS

Pediatrics

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