Risk of hypoventilation in premature infants in car seats

We examined 30 newborn infants for respiratory compromise before, during, and after placement in a recommended car seat restraining device. Twelve infants were premature with a history of apnea, eight were premature without known apnea, and 10 were born at term. Both premature groups had significant decreases in oxygen saturation while in the car seat (P less than 0.01) and more frequent desaturation episodes less than 80% (P less than 0.001). Premature infants with a history of apnea had more bradycardia events (P less than 0.05). No normal term infant had any of these problems. In addition, oxygen saturation trended downward from baseline for all premature infants during the recovery interval (P = 0.07). We conclude that currently available car seats may place premature infants at risk for significant hypoxia and ventilatory compromise.     

Can we reduce episodes of haemoglobin desaturation in full‐term babies restrained in car seats?

OBJECTIVES: To determine whether episodes of haemoglobin oxygen (SpO2) desaturation in full-term infants restrained in car seats can be reduced by a simple foam plastic infant car seat insert designed to push the body forward, with space for the protuberant occiput to lie behind the spine, and so reduce flexion of the infant's head on the trunk. METHODS: Eighteen healthy full-term babies were evaluated while restrained in an infant car safety seat with, and without, the foam insert. Infants were monitored in each position for 30 min with continuous polygraphic recording of respiratory and heart rate, nasal airflow and SpO2. RESULTS: Placement of the insert in the car seat was associated with a significant reduction in the rate of apneas with a fall in SpO2 >5% (median, interquartile range: 4.4 (0, 10.6) vs. 9.2 (5.4, 15.2) events per hour, p=0.03). The one clinically severe episode of apnea, with a fall in SpO2 of more than 30%, occurred in the car seat without the insert. CONCLUSIONS: A car seat insert that allows the newborn's head to lie in a neutral position during sleep may reduce the frequency of mild episodes of reduced SpO2 in some full-term newborn babies.     

Ventilatory changes in convalescent infants positioned in car seats

Because premature infants have been shown to be at risk for hypoxia and bradycardia when positioned in standard car seats, this study was done to confirm this finding in a larger sample, to investigate convalescent term infants in the neonatal intensive care unit for respiratory compromise in car seats, and to determine the physiologic mechanism or mechanisms responsible. Extensive multichannel polygraph recordings were obtained and pulmonary function tests were performed on 50 convalescent infants from the neonatal intensive care unit before, during, and after placement in a Cosco-Peterson First Ride car seat. Mean total dynamic compliance, total pulmonary resistance, and work of breathing improved in the car seat. Thirty percent of premature infants experienced hypoxia, bradycardia, or both in a car seat; in this group, tidal volume was lower (p = 0.02). In 11 of 16 infants with abnormal findings, oxygen desaturation was temporally related to episodes of short and mixed apnea. No term convalescent infant experienced respiratory difficulty in a car seat regardless of primary diagnosis. We conclude that premature infants may have respiratory compromise of a multifactorial nature when in car seats. Further development of car seats is necessary if such respiratory problems are to be avoided.     

The car seat: a challenge too far for preterm infants?

Physiological monitoring studies have shown that some preterm infants who are otherwise ready for hospital discharge experience episodes of oxygen desaturation, apnoea, or bradycardia when seated in standard car safety seats. The American Academy of Pediatrics recommends that all preterm infants are assessed for cardiorespiratory stability in their car seat before discharge: the "car seat challenge". This screening test has been incorporated into discharge assessments in most neonatal units in North America and is being increasingly used in the United Kingdom and elsewhere. The evidence base for the use of the car seat challenge in discharge assessment, the possible implications for infants, their families, and health services of adopting the practice, and the issues that may be resolved with further research are discussed.     

Car seat safety: literature review

After staggering numbers of infants were killed in automotive crashes in the 1970s, the American Academy of Pediatrics (AAP) recommended in 1974 universal use of car seats for all infants. However, positional problems were reported when car seats are used with premature infants less than 37 weeks gestational age as a result of head slouching and its sequelae. In 1990, the AAP responded with another policy statement introducing car seat testing. It recommended that any infant at or under 37 weeks gestational age be observed in a car seat prior to discharge from the hospital. The AAP did not give specific guidelines on type of car seat, length of testing, equipment, or personnel proficiency, however. Few nurseries have standard policies to evaluate car seats, to teach parents about car seats, or to position newborns in them, and not all hospitals actually conduct car seat challenges or have common standards for testing that is performed.     

Assessment of cardiorespiratory stability using the infant car seat challenge before discharge in preterm infants (<37 weeks’ gestational age)

Preterm infants younger than 37 weeks corrected gestational age are at increased risk for abnormal control of respiration. The infant car seat challenge has been used as a screening tool to ensure cardiorespiratory stability before discharging preterm infants from many hospitals in Canada. While it is clear that infants placed in a car seat are more likely to experience oxygen desaturation and/or bradycardia than when they are supine, neither positioning predicts an adverse neurodevelopmental outcome or mortality post-discharge. A review of the literature yielded insufficient evidence to recommend routine use of the infant car seat challenge as part of discharge planning for preterm infants. This finding has prompted a change in recommendation from a previous Canadian Paediatric Society position statement published in 2000.     

Fall and suffocation injuries associated with in-home use of car seats and baby carriers

OBJECTIVE: This paper examines two hazard patterns associated with in-home use and placement of car seats and baby carriers: 1) fall injuries resulting from placement on elevated surfaces and 2) suffocation resulting from seat overturn on soft surfaces. DESIGN: Emergency department data reporting on falls suffered by infants aged 6 months and younger, and associated with car seats and baby carriers, were provided by the U.S. Consumer Product Safety Commission's National Electronic Injury Surveillance System for 1997. National estimates were based on 396 incidents. Additionally, 15 cases of suffocation resulting from car/infant seat overturn on soft surfaces were identified through the Commission's Death Certificate and Investigation Files. RESULTS: In 1997, it is estimated that approximately 8700 infants were treated in emergency departments as a result of fall injuries suffered while using a car seat or baby carrier. More than one third of estimated falls were specifically attributed to the seat being placed on an elevated surface in the home, such as a counter or table. A search of suffocation incidents resulting from seat overturn on a soft surface produced 15 incidents. The majority of incidents occurred when the seat had been placed on a bed or waterbed. CONCLUSIONS: Many parents are unaware of hazards associated with common placement scenarios for infant car seats and baby carriers. These hazard patterns and their potential consequences need to be conveyed to new parents by pediatricians. At the same time, manufacturers have an obligation to pursue design alternatives that will reduce the likelihood of seat overturn.     

Premature infants in car seats

Advancements in health care have made it possible for many premature infants weighing less than 2.2 kg (5 lb) to be discharged from the hospital. Medical professionals, however, have no information available from which to make recommendations on which child safety seats are most appropriate for safely transporting the low-birth-weight infant. Current federal safety standards do not specify the minimum weight of an infant for which a seat is appropriate. The suitability of various types of infant car safety seats for premature infants was documented by placing 2.0-kg (4 lb 8 oz) babies in a representative sample of seat models. Ease and ability of the seat to fit the size of the infant and allow for proper positioning of the baby was noted. Each seat was measured from the seat back to crotch strap and shoulder strap to seat bottom to provide a basis for comparison of various seat models. Convertible seats with seat back to crotch strap height of 14 cm (5 1/2 in) or less provided relatively good support for the infant. Seats with longer seat back to crotch strap distances allowed the infant to slouch. Seats with lap pads or shields were uniformly unacceptable.     

Randomised trial of infant sleep location on the postnatal ward.

OBJECTIVE: To determine whether postnatal mother-infant sleep proximity affects breastfeeding initiation and infant safety. DESIGN: Randomised non-blinded trial analysed by intention to treat. SETTING: Postnatal wards of the Royal Victoria Hospital (RVI), Newcastle upon Tyne, UK. PARTICIPANTS: 64 newly delivered mother-infant dyads with a prenatal intention to breastfeed (vaginal deliveries, no intramuscular or intravenous opiate analgesics taken in the preceding 24 h). INTERVENTION: Infants were randomly allocated to one of three sleep conditions: baby in mother's bed with cot-side; baby in side-car crib attached to mother's bed; and baby in stand-alone cot adjacent to mother's bed. MAIN OUTCOME MEASURES: Breastfeeding frequency and infant safety observed via night-time video recordings. RESULTS: During standardised 4-h observation periods, bed and side-car crib infants breastfed more frequently than stand-alone cot infants (mean difference (95% confidence interval (CI)): bed v stand-alone cot = 2.56 (0.72 to 4.41); side-car crib v stand-alone cot = 2.52 (0.87 to 4.17); bed v side-car crib = 0.04 (-2.10 to 2.18)). No infant experienced adverse events; however, bed infants were more frequently considered to be in potentially adverse situations (mean difference (95% CI): bed v stand-alone cot = 0.13 (0.03 to 0.23); side-car crib v stand-alone cot = 0.04 (-0.03 to 0.12); bed v side-car crib = 0.09 (-0.03-0.21)). No differences were observed in duration of maternal or infant sleep, frequency or duration of assistance provided by staff, or maternal rating of postnatal satisfaction. CONCLUSION: Suckling frequency in the early postpartum period is a well-known predictor of successful breastfeeding initiation. Newborn babies sleeping in close proximity to their mothers (bedding-in) facilitates frequent feeding in comparison with rooming-in. None of the three sleep conditions was associated with adverse events, although infrequent, potential risks may have occurred in the bed group. Side-car cribs are effective in enhancing breastfeeding initiation and preserving infant safety in the postnatal ward.     

Car seat test for preterm infants: comparison with polysomnography

Objectives

To monitor preterm infants in a cot and a car seat and compare an observed car seat trial with polysomnography (PSG).

Design

Non‐randomised controlled trial.

Setting

Regional neonatal unit.

Patients

Preterm infants before discharge.

Interventions

Nap PSG respiratory and sleep variables were measured including gastro‐oesophageal pH. Nurse observations included respiratory distress, apnoea measured by apnoea alarm, oxygen saturation and heart rate. Infants were studied supine in a cot and then in a car seat. Nursing observations were compared with PSG during the car seat trial only. Criteria for failure of the PSG and observed tests were predefined.

Main outcome measures

Difference in respiratory instability between cot and car seat. Concurrence regarding failure of the car seat trial between nurse‐observed data and PSG.

Results

20 infants (median gestation 33 weeks (range 28–35 weeks; median postmenstrual age (PMA) at study 36.5 weeks (range 35–38 weeks)) were studied. There were sufficient car seat data on 18 infants for comparison. There were fewer central apnoeas and arousals in the cot than the car seat (p = 0.047 and p = 0.024, respectively). Airway obstruction was not more common in the car seat. Younger PMA at time of study predicted failure in both car seat (p = 0.022) and cot (p = 0.022). The nurse‐observed test had low sensitivity for predicting PSG failure but more accurately predicted airway obstruction on PSG.

Conclusions

Immature infants exhibit respiratory instability in cots and car seats. A car seat test does not accurately detect all adverse events during sleep in the seat.Since concerns were first raised about the vulnerability of preterm infants during transportation,1,2 several studies have attempted to quantify the respiratory compromise experienced by these infants while in car seats.3,4,5,6,7,8,9,10,11,12,13 Many of these studies had methodological limitations as not all measured the sleep state, or used a supine position for comparison or airflow measures to detect obstructive apnoea, or allowed for differences in postmenstrual age (PMA) at study.Although car seat trial before discharge has been incorporated into many neonatal discharge practices it has not been universally accepted as the gold standard test for assessing risk of respiratory compromise in a car seat after discharge.14,15,16 Despite many neonatal nurseries implementing variations of the practice,14 criteria defining how premature infants should be monitored, how long to monitor or what constitutes failure of the test are lacking.15,17,18 Neonatal unit car seat testing programmes therefore vary in equipment type, quality, time and outcome data.14The present study aimed to examine respiratory variables during active and quiet sleep in preterm infants ready for discharge and compare variables recorded supine in a cot with those recorded supine in a car seat, in particular, to determine whether more obstructive events occurred after transfer to the car seat. A second aim was to compare car seat testing before discharge with concurrent polysomnography (PSG) recording to determine if a nurse‐observed test was a sensitive enough predictor of respiratory instability, and in particular airway obstruction, found on PSG.     

Hospital-based rental programs to increase car seat usage

The ability of hospital-based car seat rental programs to provide car seats inexpensively throughout an entire state and the effect of these rental programs on car seat usage by newborns were evaluated. In July 1979 individuals and groups committed to child passenger safety formed a coalition called Vermont SEAT (Seatbelts Eliminate Automobile Tragedies). During the next 3 years SEAT asked the major hospitals in the state to allow volunteers to operate car seat rental programs on their premises. The number of rental programs increased from 0 to 13; the percentage of newborns born in a hospital with a rental program increased from 0% to 99%. The estimated statewide rate of car seat usage by newborns, based on observations at discharge at five hospitals, increased from 15% to 70%. These findings suggest that a network of hospital-based car seat rental programs operated by volunteers can make car seats readily available throughout a state or region, and can significantly increase car seat usage by newborns. It is recommended that such programs be a part of comprehensive strategies to improve child passenger safety.     

Misuse of car safety seats

Correct use of car seats for small children is essential to prevent serious injuries and death from automotive accidents. Failure to use a car seat properly can contribute to serious injury or death of a child. A case study in which misuse of a car seat occurred is reported. The infant died of hemorrhage and shock secondary to liver laceration which resulted from excessive pressure over the abdomen sustained on impact. Surveys of car seat use for small children prior to and following a child restraint law are also reported. Observers noted types of car seats and specific forms of misuse. Survey results suggest that parents are more likely to misuse car seats for infants than toddlers. Medical professionals can reinforce the importance of proper car seat use by incorporating specific car seat use questions into the patient interview and by providing educational materials.     

Evaluation of an infant car seat program in a low-income community

This study was designed to assess the influence of an infant car seat loan program on car seat utilization in a low-income community. An adjacent community, with no car seat program, was chosen for comparison. Systematic observations were made in the two neighborhoods, and this information was supplemented by telephone interviews. Greater use of infant seats was observed in the intervention community (41%) than in the control community (27%) for infants younger than 6 months old. The rate of observed utilization of infants between 7 and 18 months of age increased to 50% on average, but no significant differences were noted between the two communities. These findings suggest that a community-based loan program can produce short-term increases in car seat use rates for infants, even in a low-income community. A strategy to facilitate continued accessibility to such restraints is needed, however, to maintain these improvements.     

Nocturnal oximetry in infants with cystic fibrosis.

AIM: To investigate whether children with cystic fibrosis under 3 years of age have disordered breathing and episodes of oxygen desaturation during sleep. METHODS: We studied 19 infants (9 boys and 10 girls) with cystic fibrosis, mean age 13.1 months (range 3-36 months) and 20 age and sex matched healthy subjects. Patients and controls underwent an overnight polysomnographic study and respiratory function testing on the following morning. RESULTS: Seven patients with ongoing respiratory tract inflammation had disordered breathing and episodes of oxygen desaturation during sleep. Pulse oximetry showed a significantly lower mean oxygen saturation (SaO(2)) and a higher percentage of total sleep time spent with SaO(2) less than 93% in symptomatic children than in controls. CONCLUSION: Results suggest that infants and young children with cystic fibrosis and mild airways inflammation (rhinitis, cough, red throat) have episodes of oxygen desaturation during sleep.     

Potentially dangerous sleeping environments and accidental asphyxia in infancy and early childhood

Infants and young children may be exposed to a variety of dangerous situations when left sleeping in cots, chairs, or beds. A review of 30 cases of accidental asphyxia occurring in infants and young children who had been left to sleep unattended was undertaken from the necropsy and consultation files of the Adelaide Children's Hospital. Causes of death included hanging from loose restrainers, clothing, or a curtain cord (12 cases), positional asphyxia/wedging from slipping between a mattress and bed/cot sides or wall, or from moving into a position where the face was covered and the upper airway occluded (16 cases), and suffocation from plastic bed covers (two cases). Cases of co-sleeping in bed with an adult and of non-accidental asphyxia were not included in this review. As the pathological findings were on occasion identical to those that are typically found in sudden infant death syndrome, adequate death scene examination was vital in several cases to allow identification of lethal sleeping environments and to enable steps to be taken to minimise the risk of future deaths due to similar situations. For example, two cases in which infants asphyxiated in rocking cradles led to the investigation of the cradles and to formulation of specific safety recommendations regarding the angle of tilt. Two infants who died after becoming wedged between the back of a couch and a co-sleeping parent in one case and cushions in the other, would indicate that this also represents a potentially lethal sleeping position. Other dangerous situations involved infant car seat restraints, seats with loose harnesses, cots with movable sides or projecting pieces, thin plastic mattress/pillow coverings, and beds with spaces between the mattress and cot side or wall. Lack of supervision at the time of death was a feature of each case.     

Sudden infant deaths in sitting devices.

BACKGROUND: As episodes of decreased oxygenation levels have been recorded in premature infants placed in car seats, it is believed that these infants are at risk of life-threatening events and death. No data on the prevalence of such infant deaths are available. The aim of our study was to determine the incidence of sudden deaths in infants occurring in sitting devices in a whole population and to determine whether premature infants account for a disproportionate number of these deaths. DESIGN: Retrospective population-based cohort study reviewing all cases of sudden unexpected death in infants between birth and 1 year of age that occurred in the province of Quebec between January 1991 and December 2000. RESULTS: Of the 508 deaths reviewed, 409 were unexplained and 99 were explained after investigation. Seventeen deaths occurred in a sitting device, of which 10 were unexplained. There was no excess of premature infants dying. However, there was an excess of infants of less than 1 month of age found to have died in a sitting position in the unexplained death group. In addition, three infants who died in a sitting position had an increased risk of upper airway obstruction. CONCLUSION: Although very few deaths occurred in car seats, our results suggest that caution should be used when placing younger infants in car seats and similar sitting devices, whether the infants have been born prematurely or not. We also recommend that more attention be given to infants at increased risk of upper airway obstruction.     

Infant bath seats, drowning and near-drowning

OBJECTIVE: To investigate the possible role of infant bathtub seats in drowning and near-drowning episodes in infants. METHODS: A review was conducted of the files of the Forensic Science Centre and Child Protection Unit, Women's and Children's Hospital, Adelaide, South Australia, for significant immersion incidents in infants involving bathtub seats from January 1998 to December 2003. RESULTS: A total of six cases of drowning occurred over the 6-year period of the study in children under 2 years of age, including two infants. One of these cases, a 7-month-old boy, had been left unattended for some time in an adult bath in a bathtub seat. He was found drowned, having submerged after slipping down and becoming trapped in the seat. Three near-drowning episodes occurred in children under the age of 2 years, including two boys aged 7 and 8 months, both of whom had been left for some time in adult baths in bath seats. Both were successfully resuscitated and treated in hospital. CONCLUSIONS: These cases demonstrate the vulnerability of infants to immersion incidents when left unattended in bathtubs. Bathtubs are particularly dangerous for infants as the slippery and smooth surfaces predispose to loss of balance and make escape from water difficult. Infant bathtub seats may give parents and child carers a false sense of security leading to infants being left unattended. Unfortunately, however, infants may fall out of, or slip and become trapped in, such seats. Infants and young children cannot be left unsupervised in water, and devices used as bathing aids such as bathtub seats may contribute to immersion incidents.     

Prehospital Discharge Car Safety Seat Testing of Infants After Congenital Heart Surgery

Background This study aimed to expand the American Academy of Pediatrics (AAP) car safety seat testing recommendation to include high-risk infants after cardiac surgery. Methods Car safety seat testing (≤4 days before discharge), performed according to AAP guidelines, was retrospectively reviewed for 66 postoperative infants. Failure was defined as apnea, bradycardia, or oxygen desaturation. Results The average birth weight of the study infants was 3.1 ± 0.5 kg. Two patients were born at less than 37 weeks gestation. Surgical procedures included modified Blalock–Taussig shunt technique (n = 15), arterial switch operation (n = 12), Norwood Sano modification (n = 11), coarctation repair (n = 8), repair of tetralogy of Fallot (n = 6), repair of truncus arteriosus (n = 4), repair of total anomalous pulmonary venous return (n = 3), pacemaker placement (n = 2), repair of interrupted aortic arch and ventriculoseptal defect (VSD) (n = 1), repair of coarctation and VSD (n = 1), orthotopic heart transplant (n = 1), repair of VSD (n = 1), and patent ductus arteriosus ligation (n = 1). The average age at discharge was 28 ± 21 days. Four patients (6%) failed car safety seat testing because of a fall in oxygen saturation. One of the four patients passed on retesting after parental education, whereas three of the four (75%) were discharged home in a supine car safety seat. There was no relationship between the type of surgery and car safety seat test failure. Conclusion It may be beneficial to extend the AAP recommendations for car safety seat testing to include high-risk infants after cardiac surgery.     

Cervical spine fractures sustained by young children in forward-facing car seats

Child passenger safety restraint laws have reduced the number of children killed or injured in motor vehicle accidents in the past few years. However, the increased used of child safety seats has brought with it an increase in the misuse of these devices. High cervical spine injuries sustained by five children less than 2 years of age while in forward-facing car seats are described. In the cases of three children, the care safety seat use was correct. Misuse of car seats and anatomic and biomechanical factors in the cervical spines of infants and young children appear to have contributed to the occurrence of these previously rare injuries. Like seat belts, car safety seats are now a factor in child passenger injury characteristics, and therefore, car safety seat design merits reevaluation. In light of this development, public and parent education by health care professionals concerning the correct use of car safety seats is necessary.     

Car seat safety for high-risk infants

Most neonates discharged from the hospital are able to go home in a standard car safety seat. Some infants, though, require special devices to ensure their safe travel. NICU nurses must have the knowledge and skills to comfortably and competently give vital information to parents preparing to take their infant home. This article is intended to increase awareness among NICU nurses of the potential dangers babies face when placed in a car seat. It provides a basic overview of car seat safety for infants being discharged home from an NICU and includes references for those who seek further information on this topic.