Simple car seat insert to prevent upper airway narrowing in preterm infants: a pilot study

Post-discharge outcomes of failed car seat tolerance screens: A case-control and follow-up study

BACKGROUND

Despite widespread implementation, limited data exists relating morbidity or adverse outcomes to Car Seat Tolerance Screen (CSTS) result in preterm and low birth weight (LBW) neonates. The objective of this study was to determine longer term post-discharge outcomes of infants who failed a CSTS.

METHODS

We performed a case control study evaluating outcomes of infants born over one year who failed vs. passed an initial CSTS, utilizing both retrospective medical record review and parental survey data 2-3 years after discharge. Subjects were matched one case of failed CSTS to two controls who passed CSTS based on sex, gestational age, and BW. We performed bivariate analysis of clinical and demographic risk factors comparing those who passed vs. failed CSTS.

RESULTS

We identified 19 subjects who failed and matched to 37 controls. Cases were significantly more likely to be diagnosed with obstructive sleep apnea (p = 0.027), asthma (p = 0.016), and be treated with albuterol (p = 0.008). We did not find differences in frequency of urgent care visits or hospital admissions between the groups. Although more of the cases were noted to have developmental delays, the difference was not statistically significant.

CONCLUSION

This is the first study to evaluate longer term post-discharge outcomes of subjects having undergone CSTS. Subjects who failed CSTS had significantly increased incidence of respiratory diagnoses such as OSA and asthma than matched controls by 2-3 years after discharge. Larger studies are necessary to further evaluate these findings, but this does provide data that CSTS may be useful in identifying at risk neonates.

Car Seat Tolerance Screening in the Neonatal Intensive Care Unit: Failure Rates, Risk Factors, and Adverse Outcomes

OBJECTIVE

To characterize the epidemiology of Car Seat Tolerance Screening (CSTS) failure and the association between test failure and all-cause 30-day postdischarge mortality or hospital readmission in a large, multicenter cohort of preterm infants receiving neonatal intensive care.

STUDY DESIGN

This retrospective cohort study used the prospectively collected Optum Neonatal Database. Study infants were born at <37 weeks of gestation between 2010 and 2016. We identified independent predictors of CSTS failure and calculated the risk-adjusted odds of all-cause 30-day mortality or hospital readmission associated with test failure.

RESULTS

Of 7899 infants cared for in 788 hospitals, 334 (4.2%) failed initial CSTS. Greater postmenstrual age at testing and African American race were independently associated with decreased failure risk. Any treatment with an antacid medication, concurrent use of caffeine or supplemental oxygen, and a history of failing a trial off respiratory support were associated with increased failure risk. The mean adjusted post-CSTS duration of hospitalization was 3.1 days longer (95% CI, 2.7-3.6) among the infants who failed the initial screening. Rates of 30-day all-cause mortality or readmission were higher among infants who failed the CSTS (2.4% vs 1.0%; P = .03); however, the difference was not significant after confounder adjustment (OR, 0.38; 95% CI, 0.11-1.31).

CONCLUSION

CSTS failure was associated with longer post-test hospitalization but no difference in the risk-adjusted odds for 30-day mortality or hospital readmission. Whether CSTS failure unnecessarily prolongs hospitalization or results in appropriate care that prevents adverse postdischarge outcomes is unknown. Further research is needed to address this knowledge gap.

Predictors of Persistent Infant Car Seat Challenge Failure

BACKGROUND

Premature and other at-risk infants can experience cardiorespiratory problems when positioned in their car seats. The American Academy of Pediatrics recommends that all premature and at-risk infants undergo a period of observation in their car seat to monitor for apnea, bradycardia, and oxygen desaturation before hospital discharge. This Infant Car Seat Challenge (ICSC) is used to determine readiness for infant travel in a car seat. Infants failing the ICSC are discharged home in car beds and referred for a follow-up screen in the outpatient clinic.

PURPOSE

The purpose of this study was to identify predictors for infants failing the follow-up ICSC after hospital discharge.

METHODS/SEARCH STRATEGY

A retrospective, cross-sectional study design was used to examine charts of 436 infants referred from across New England, to Boston Children's Hospital's, Center for Healthy Infant Lung Development clinic between August 2008 and May 2015 for a follow-up ICSC.

FINDINGS/RESULTS

Infants who failed the follow-up ICSC had statistically significant lower weights (0.27 ± 0.14 kg, difference ± standard error, P = .03) and younger postmenstrual ages (0.9 ± 0.4 weeks, P = .03). History of a cardiac condition (odds ratio, 3.6; 95% confidence interval, 1.5-8.5; P = .005) and respiratory illness (odds ratio, 2.1; confidence interval, 1.1 to 4.2; P = .03) were significant predictors of ICSC failure.

IMPLICATIONS FOR PRACTICE

A follow-up ICSC is recommended for the safe transition of infants from a car bed to a car seat.

IMPLICATIONS FOR RESEARCH

Further research is needed to investigate the causes of ICSC failure among high-risk infant populations.

Is the infant car seat challenge useful? A pilot study in a simulated moving vehicle

BACKGROUND AND OBJECTIVE

The American Academy of Pediatrics recommends that preterm infants complete a predischarge 'car seat challenge' observation for cardiorespiratory compromise while in a car seat. This static challenge does not consider the more upright position in a car or the vibration of the seat when the car is moving. This pilot study was designed to assess the cardiorespiratory effects of vibration, mimicking the effect of being in a moving car, on preterm and term infants.

METHODS

A simulator was designed to reproduce vertical vibration similar to that in a rear-facing car seat at 30 mph. 19 healthy newborn term and 21 preterm infants, ready for hospital discharge, underwent cardiorespiratory measurements while lying flat in a cot (baseline), static in the seat (30°), simulator (40°) and during motion (vibration 40°).

RESULTS

Median test age was 13 days (range 1-65 days) and median weight was 2.5 kg (IQR: 2.1-3.1 kg).Compared with baseline observations, only the total number of desaturations was significantly increased when infants were placed at 30° (p=0.03). At 40°, or with vibration, respiratory and heart rates increased and oxygen saturation decreased significantly. Profound desaturations <85% significantly increased during motion, regardless of gestational age.

CONCLUSIONS

This is the first study to assess the effect of motion on infants seated in a car safety seat. Term and preterm infants showed significant signs of potentially adverse cardiorespiratory effects in the upright position at 40°, particularly with simulated motion, not identified in the standard challenge. A larger study is required to investigate the significance of these results.

Screening for cardiopulmonary events in neonates: a review of the infant car seat challenge

The infant car seat challenge (ICSC), or period of observation in a car safety seat before discharge to monitor for episodes of apnea, bradycardia and desaturation, is one of the most common tests performed on preterm neonates in the United States. However, the utility of the ICSC to identify infants at risk for adverse cardiopulmonary events in the car seat remains unclear. Minimal evidence exists to guide clinicians in performance of this test including appropriate inclusion criteria and failure criteria. In this article, the origins of the ICSC are discussed as well as potential etiologies of desaturations and bradycardia in the car seat position. Current literature on implementation, inclusion and failure criteria, incidence of failure and data on the meaning of a 'passed' vs 'failed' ICSC are discussed. Emphasis is made on minimizing time in car seats and seated devices given concern over the risk of desaturations.

Are baby hammocks safe for sleeping babies? A randomised controlled trial

AIM

Two reports of infants found dead after sleeping in baby hammocks have raised international concern about the safety of infant hammocks. We therefore tested whether hammock sleep affected oxygenation in infants, when they were at an age of high risk of sudden, unexpected infant death.

METHODS

Healthy, full-term 4- to 8-week-old infants were randomised to sleep either in a commercially available hammock (n = 14) or a standard bassinet (n = 9), and sleep state, oxygen desaturation (a fall in peripheral haemoglobin oxygen saturation (SpO2 ) ≥ 4%, for ≥ 4 sec from baseline to nadir), apnoea and hypopnoea, and mean SpO2 were analysed.

RESULTS

There was no significant difference in mean SpO2 (both 98.5%) or rate of oxygen desaturation events between the hammock and the bassinet cot (mean ± SD, 24 ± 20 vs. 28 ± 23 events per hour), but infants slept less in the hammock (59 ± 31 vs. 81 ± 34 min, p < 0.02).

CONCLUSION

When correctly used, the hammock sleep position did not compromise the upper airway of sleeping infants. The significance of shorter duration of sleep in the hammocks is unclear. These findings should not be applied to all baby hammocks, nor to older babies, particularly once the infant can roll. Given that it is not possible to predict when an infant will be able to roll, we strongly recommend that hammocks should not be used for unsupervised sleep.

Randomized controlled trial of a car safety seat insert to reduce hypoxia in term infants

OBJECTIVE

To test the hypothesis that a foam plastic insert that allows the infant head to rest in a neutral position in sleep may prevent obstruction of the upper airway and thus reduce episodes of reduced oxygenation in term infants in car seats.

METHODS

Healthy full-term babies were randomized to be studied during sleep while restrained in an infant car safety seat either with or without the insert, with continuous polysomnographic recordings with sleep video.

RESULTS

Seventy-eight infants (39 in each group) had polysomnogram recordings at a mean of 8 days of age. Both groups showed a small fall in mean hemoglobin oxygen saturation (SpO2) over the first hour of sleep. There was no difference between insert and no insert in the rate of moderate desaturations (a fall in SpO2 ≥ 4% lasting for ≥ 10 seconds, mean ± SEM, 17.0 ± 1.5 vs 17.2 ± 1.5/hour), or mean SpO2 during sleep. The insert was associated with a significant reduction in the rate of obstructive apnea (0.3 ± 0.1 vs 0.9 ± 1.5/hour, P < .03), the severity of desaturation events (minimum SpO2 82% ± 1% vs 74% ± 2%, P < .001), and time with SpO2 <85% (0.6% ± 0.3% vs 1.8% ± 1.4%, P = .03).

CONCLUSIONS

In full-term newborn infants, a car seat insert that helps the head to lie in a neutral position was associated with reduced severity of desaturation events but not the overall rate of moderate desaturations.

Development of a finite element/multi-body model of a newborn infant for restraint analysis and design

A finite element/multi-body model of a newborn infant has been developed by researchers at the University of Windsor. The geometry of this model is derived from a Nita newborn hospital training mannequin. It consists of 17 parts: eight upper and lower limb segments, the torso, head, and a seven-segment neck with seven translational and eight rotational joints. Anthropometry is consistent with hospital growth charts, measurements requested from health professionals and data from the open literature. The biomechanical properties of the model (i.e. joint stiffnesses) are implementations of data identified in the open literature. The model has been validated with respect to studies of the biomechanics of shaken baby syndrome, infant falls and the Q0 anthropomorphic testing device. A significant conclusion of this study is that the kinetics of the Q0 neck is not biofidelic. This model is currently used in an analysis of airway patency for infants in modern automotive child restraints.

Weight and age as predictors for passing the infant car seat challenge

OBJECTIVE

The American Academy of Pediatrics recommends observation of preterm and at-risk infants in their car seat before hospital discharge to screen for breathing problems. This observation period, which we refer to as the infant car seat challenge (ICSC), is used to determine readiness for travel in a car seat. Infants who fail the ICSC are recommended to travel in a car bed. Limited data exist to identify risk factors for failing the ICSC, and no guidelines are available to facilitate transition from car beds to car seats. The purpose of this study was to determine whether weight and age are predictors for passing the ICSC.

METHODS

This retrospective study evaluated 43 infants referred to the Children's Hospital Boston Center for Healthy Infant Lung Development for a repeat ICSC after initial failure and 37 infants who passed or failed their initial ICSC at the Caritas Saint Elizabeth's Medical Center. Gender, birth weight, gestational age (GA), weight (ICSC weight), corrected GA, and chronological age at time of ICSC were extracted, and logistic regression analysis was performed.

RESULTS

The average GA at birth of infants referred was 35 weeks 2 days (+/-2 weeks 3 days), and almost equal numbers of boys and girls were referred. A majority of infants passed their initial rechallenge (38 [88%] of 43). Infants who failed the repeat challenge were slightly smaller (3327 +/- 927 vs 3913 +/- 936 g) and younger at time of retesting (CGA 40 weeks 5 days vs 42 weeks 5 days; chronological age 39.2 vs 52.2 days). Neither weight nor age at initial or repeat ICSC predicted passing the ICSC.

CONCLUSIONS

This study suggests that ICSC screenings remain the safest method for transitioning preterm infants from a car bed to a car seat.

Effect of sitting position on respiratory status in preterm infants

OBJECTIVE

To evaluate whether using a sitting-type car safety seats for preterm infants is advisable.

PATIENTS AND METHODS

A total of 65 preterm infants underwent polysomnography in the supine and sitting positions. The infants with <95% of SpO(2) were assigned to the desaturation (DS) group. Their backgrounds, breathing patterns, and breathing types were analyzed.

RESULTS

Of the 65 cases, 18 were assigned to the DS group. No significant differences were observed between the DS and non-DS groups in their background characteristics. Of the 18 DS cases, 15 were included in the non-obstructive group (8, periodic breathing; 6, tachypnea; 1, irregular breathing).

CONCLUSIONS

Immaturity of the respiratory center and decompensation for the respiratory changes caused by the sitting position were suspected to cause DS in infants. Sitting-type car safety seats should be used with caution for preterm infants, and all preterm infants need to be screened by polysomnographic examination in the sitting position.

A comparison of respiratory patterns in healthy term infants placed in car safety seats and beds

OBJECTIVE

The purpose of this work was to compare the incidence of apnea, hypopnea, bradycardia, or oxygen desaturation in healthy term newborns placed in hospital cribs, infant car safety beds, or infant car safety seats.

METHODS

A consecutive series of 200 newborns was recruited on the second day of life. Each subject was studied while placed in the hospital crib (30 minutes), car bed (60 minutes), and car seat (60 minutes). Physiologic data, including oxygen saturation, frequency, and type of apnea, hypopnea, and bradycardia were obtained and analyzed in a blinded manner.

RESULTS

The mean oxygen saturation level was significantly different among all of the positions (97.9% for the hospital crib, 96.3% for the car bed, and 95.7% for the car seat; P < .001). The mean minimal oxygen saturation level was lower while in both safety devices (83.7% for the car bed and 83.6% for the car seat) compared with in the hospital crib (87.4%) (P < .001). The mean total time spent with an oxygen saturation level of <95% was significantly higher (P = .003) in both safety devices (car seat: 23.9%; car bed: 17.2%) when compared with the hospital crib (6.5%). A second study of 50 subjects in which each infant was placed in each position for 120 minutes yielded similar results.

CONCLUSIONS

In healthy term newborns, significant desaturations were observed in both car beds and car seats as compared with hospital cribs. This study was limited by lack of documentation of sleep stage. Therefore, these safety devices should only be used for protection during travel and not as replacements for cribs.

Positioning of Preterm Infants for Optimal Physiological Development: a systematic review

EXECUTIVE SUMMARY

Positioning of preterm infants is a basic task of neonatal nursing care. A variety of outcomes are affected by different body positioning of preterm infants. This review evaluates the clinical evidence of the effects of positioning of preterm infants with regard to physiological outcomes and sleep states.

OBJECTIVES

To conduct a systematic review to determine the best available evidence related to the positioning of preterm infants. The specific review questions addressed were: the physiological outcomes affected by different positioning, and the best position for promoting sleep.

CRITERIA FOR CONSIDERING STUDIES FOR THIS REVIEW

This review considered all studies that included infants born before 37 weeks of gestational age in any hospital setting. Outcomes included measures for physiologic effects and sleep state. The review primarily considered any randomized clinical trails (RCTs) that explored different positions in preterm infant but also included quasi-experimental designs.

SEARCH STRATEGY FOR IDENTIFICATION OF STUDIES

The search sought to find published and unpublished studies. The database search included: Pubmed, CINAHL, ProQuest, EMBASE, Science Direct, and Dissertation Abstracts International. Studies were additionally identified from reference lists of all studies retrieved.

ASSESSMENT AND DATA EXTRACTION

All studies were checked for methodological quality by two reviewers and data was extracted using tools developed by the Joanna Briggs Institute.

DATA ANALYSIS

The study results were pooled in statistical meta-analysis using Review Manager Software and summarized in narrative form where statistical pooling was not appropriate or possible.

RESULTS

Thirty two studies were included in the review. The results of this review support the prone position in preterm infants for improvement of arterial oxygen saturation, improved lung and chest wall synchrony of respiratory improvements, decreased incidence of apnea in infants with a clinical history of apnea, promoted sleep, and decreased gastroesophageal reflux. However, the prone position increased postural abnormalities, orthopaedic abnormalities of the feet, and delayed developmental musculature. The combined use of a postural support roll and a postural nappy while very preterm infants are nursed, improved hip and shoulder posture up to term postmenstrual age. The change in body position from horizontal to head-up tilt in very immature and unstable infants may affect the cerebral homodynamic. The management of position per se may not be sufficient for assisting preterm neonates to cope with the painful procedure. Furthermore, preterm infants are susceptible to oxygen desaturation in car seats and carrying slings.

CONCLUSION

Prone positioning was shown to have many advantages for prematurely born infants. But the longer, deep sleep period and fewer awakenings associated with a prone position would support higher vulnerability for preterm infants to sudden infant death syndrome (SIDS). Therefore, all preterm infants placed in the prone position should have continuous cardio-respiratory and oxygen saturation monitoring. Preterm infants should be placed in a properly supported position to ensure functional support of all parts of the body as well as ensuring physical safety. In addition, preterm infants should not be left unattended in car safety seats and carrying slings.

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.

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.

Effect of pacifier use on mandibular position in preterm infants

AIM

It has been hypothesized that the association of pacifier use with reduced risk of sudden infant death is mediated by forward movement of the mandible and tongue that helps open the upper airway. Our aim was to examine whether the mandible is moved forward when an infant is sucking on a pacifier, and if so, whether the mandible remains advanced after the pacifier is removed.

METHODS

In sixty clinically stable premature infants (corrected gestation age 36.5 +/- 0.3 weeks, mean +/- SEM) the distance from each ear where the pinna met the cheek to the most prominent point of the chin was measured bilaterally, and the average was used as an index of mandibular position. Mandibular position was determined before and after allowing the infants to suck on a pacifier for 10-15 min, and after removing the pacifier.

RESULTS

There was a significant forward movement of the mandible when the infants were sucking on the pacifier (59.5 +/- 0.7 vs. 58.6 +/- 0.7 mm, p = 0.001), with no significant change after the pacifier was removed.

CONCLUSIONS

Pacifier use in preterm infants was associated with a small significant forward displacement of the jaw. These data suggest that pacifier use may help protect the upper airway.

Stability of the infant car seat challenge and risk factors for oxygen desaturation events

OBJECTIVES

To explore the stability of the one-point Infant Car Seat Challenge and risk factors that may be associated with oxygen desaturation events.

DESIGN, SETTING, AND PARTICIPANTS

This descriptive, nonexperimental, observational study examined the responses of 49 premature infants during two 90-minute Infant Car Seat Challenges at a tertiary health care institution.

MAIN OUTCOME MEASURES

Three Infant Car Seat Challenge outcomes were explored: (a) pass/fail rates following two Infant Car Seat Challenge observation periods, (b) oxygen saturation and desaturation patterns during two Infant Car Seat Challenges, and (c) the association between oxygen desaturation events and infants' chronological, gestational, and corrected gestational ages.

RESULTS

The findings indicated that 86% of premature infants had stable results, 8% passed Infant Car Seat Challenge 1 but not Infant Car Seat Challenge 2, and 6% failed Infant Car Seat Challenge 1 and passed Infant Car Seat Challenge 2. In addition, the odds for oxygen desaturation events increased for infants born at less than or equal to 34 weeks gestation and hospitalized longer than 7 days.

CONCLUSIONS

The Infant Car Seat Challenge success rate for identifying infants at risk for oxygen desaturation events was equal to or better than that of other screening tests for newborn medical conditions. The findings of this study will assist neonatal health care providers in making appropriate recommendations for infants' safe travel at discharge.

Apparently life threatening events in infant car safety seats

Young infants should not be left unattended to sleep in standard car safety seats

Sudden Infant Death Syndrome and the time of death: factors associated with night-time and day-time deaths

OBJECTIVE

To investigate the diurnal occurrence of Sudden Infant Death Syndrome (SIDS) and interaction with established risk factors in the infant sleeping environment.

METHODS

A 3 year population-based case-control study, in five English Health Regions. Parentally defined day-time or night-time deaths of 325 SIDS infants and reference sleep of 1300 age-matched controls.

RESULTS

The majority of SIDS deaths (83%) occurred during night-time sleep, although this was often after midnight and at least four SIDS deaths occurred during every hour of the day. The length of time from last observed alive until the discovery of death ranged from <l to 14 h but was not significantly different from the corresponding sleep period amongst the controls. Amongst the day-time deaths, 38% of the infants were observed alive 30 min prior to discovery and 9% within 10 min. The risk of placing infants asleep on their side was more marked for day-time deaths (interaction: P = 0.0001) nearly half of whom were found prone, while the risk associated with paternal smoking [OR = 3.25 (95%CI: 1.88-5.62)] was more marked for night-time deaths (interaction: P = 0.02). The adverse effect of unsupervised sleep recognized for night-time practice [OR = 5.38 (95%CI: 2.67-10.85)] was also significant for day-time sleep [OR = 10.57 (95%CI: 1.47-75.96)]. Significantly more (P = 0.002) unobserved SIDS infants (24.8%) were found with bedclothes over the head compared with those SIDS infants where a parent was present in the room (11.3%).

CONCLUSIONS

SIDS can happen at any time of the day and relatively quickly. Parents need to be made aware that placing infants supine and keeping them under supervision is equally important for day-time sleeps.

Comparison of respiratory physiologic features when infants are placed in car safety seats or car beds

OBJECTIVE

The objective of this study was to compare the respiratory physiologic features of healthy term infants placed in either a car bed or a car safety seat.

METHODS

Within the first 1 week of life, 67 healthy term infants were recruited and assigned randomly to be monitored in either a car bed (33 infants) or a car safety seat (34 infants). Physiologic data, including oxygen saturation and frequency and type of apnea, were obtained and analyzed in a blinded manner.

RESULTS

The groups spent similar amounts of time in the devices (car bed: 71.6 minutes; car seat: 74.2 minutes). The mean oxygen saturation values were not different between the groups (car bed: 97.1%; car seat: 97.3%). The percentages of time with oxygen saturation of < 95% were also similar for the 2 groups (car bed: 11.8[corrected]%; car seat: 18.3[corrected]%). In both groups, a number of infants spent high percentages of study time with oxygen saturation of < 95%. The 6 infants with the most time at this level were all in the car safety seat group (54%-63% of study time). Values for the 6 infants in the car bed group with the most time at this level were lower (20%-42%). This difference in the duration of oxygen saturation of < 95% was not statistically significant. The mean end-tidal carbon dioxide levels and the numbers of episodes of apnea were similar for the 2 groups.

CONCLUSIONS

The respiratory physiologic features of infants in the 2 car safety devices were observed to be similar. Of note, substantial periods of time with oxygen saturation of < 95% were surprisingly common in both groups.

Airway management in infants and children

Anaesthesiologists, paediatricians, paediatric intensivists and emergency physicians are routinely challenged with airway management in children and infants. There are important differences from adult airway management as a result of specific features of paediatric anatomy and physiology, which are more relevant the younger the child. In addition, a number of inherited and acquired pathological syndromes have significant impact on airway management in this age group. Several new devices--e.g. different types of laryngeal mask airways in various sizes, small fibre-endoscopes--have been introduced into clinical practice with the intention of improving airway management in this age group. Important new studies have gathered evidence about risks and benefits of certain confounding variables for airway problems and specific techniques for solving them. Airway-related morbidity and mortality in children and infants during the perioperative period are still high, and only a thorough risk determination prior to and continuous attention during the procedure can reduce these risks. Appropriate preparation of the available equipment and frequent training in management algorithms for all personnel involved appear to be very important.

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.

Risk of cardio-respiratory abnormalities in preterm infants placed in car seats: a cross-sectional study

BACKGROUND

Little is known about the factors that predispose to the occurrence and severity of cardio-respiratory symptoms during the placement of a prematurely born infant in a car seat. The impact of gestational age, weight at discharge and infant's pre-existing cardio-respiratory status (in the supine position) on cardio-respiratory function during pre-discharge testing in a car seat (semi-upright position) has not been investigated.

METHODS

The cardio-respiratory function of 42 preterm neonates with gestational age 24 to 35 weeks and discharge weight 1790 to 2570 grams were monitored for 45 minutes before, during, and after placement in a car seat. The occurrence of periodic breathing, apnea, bradycardia, or decreased oxygen saturation (SaO2) was analyzed.

RESULTS

Prior to the car seat testing, 15 (35.7%) infants displayed one or more abnormalities of cardio-respiratory function. During the car seat testing, 25 (59.6%) infants had periodic breathing, 33 (78.2%) had oxygen saturation <90%, 14 (33.3%) had bradycardia less than 80 beats per minute, and 35 (83.3%) had a combination of these symptoms. Infants, both with and without pre-existing cardio-respiratory abnormalities, had an almost equal probability (80% vs. 83.3%) for the development of cardio-respiratory symptoms during placement in the car seat. Weight at discharge ([less than or equal to] 2,000 grams) but not the gestational age (<28 weeks or [greater than or equal to] 28<37 weeks), was associated with either increased episodes of oxygen desaturation or the combination of cardio-respiratory symptoms that were seen during the placement of these infants in the car seat. Repositioning from the car seat to the supine position showed normalization of cardio-respiratory function in the majority (83%) of the tested infants. None of the tested clinical factors were associated with the severity of the cardio-respiratory symptoms.

CONCLUSION

Pre-discharge testing of the cardio-respiratory function of preterm infants during placement in a car seat is important for the prevention of cardio-respiratory symptoms during their transportation. However, the high risk for developing cardio-respiratory symptoms will require the consideration of an alternative mode of safe home transportation for preterm infants; especially those with a discharge weight less than 2,000 grams.

A primer on Apnea of prematurity

Apnea, the cessation of respiratory airflow, can begin in many preterm infants in the first week of life and can last until the day of discharge or beyond. This article provides an overview of the complex anatomic, physiological, and developmental mechanisms related to immaturity of both the central nervous system and musculature of the pulmonary system, that contribute to apnea of prematurity. Apnea of prematurity is a diagnosis of exclusion; an array of other conditions and stimuli can also cause apnea, including infections, pulmonary disease, and intracranial pathology. The standard clinical management of apnea, including cutaneous stimulation, methylxanthine therapy, and continuous positive airway pressure or ventilatory support, are discussed as well as newer investigational therapies, such as olfactory stimulation. Emerging evidence on the long-term neurodevelopmental impact of apnea is reviewed. Nursing measures to prevent and manage apnea are reviewed with an emphasis on parent education and preparation for discharge. Apnea resolves in most preterm infants as they approach term corrected gestational age; however, if it does not, options include continued hospitalization or, for infants with stable apnea, discharge with a home apnea monitor.