Progress in perinatal and neonatal care has resulted in increased survival of very preterm infants (typically ≤ 1500 grams and < 34 weeks). However, preterm infants’ growth and developmental outcomes vary with illness severity and degree of neurological insult (Ge, Mirea, Yang, Bassil, Lee & Shah, et al., 2013; Manuck et al., 2016). In addition, unpredictable variations in outcomes exist even among healthy preterm infants (Vohr, 2014). One source of outcome variability is felt to lie in the long-term exposure to environmental stress (Blinded Authors, 2017) because preterm infants are more easily excited and are often unable to self-regulate. Strategies to minimize environmental stress have been identified and termed individualized supportive developmental care with an overall goal to promote short- and long-term infant outcomes (Macho, 2017). One protective strategy that has been commonly adopted includes the grouping of care activities around a single caregiving event described as “clustering” or “bundling care”. Individualized developmental care suggests that a bundled care event (BCE) should be halted if an infant displays signs of distress. Yet, the number and type of caregiving activities that are included in BCEs and the length of these events has not been systematically researched. Nor has the number, type, or sequence of caregiving activities that negatively impacts infant physiologic status been studied. The inclusion and exclusion of certain care activities in any individual care event is often dictated by the infant’s treatment plan or needs, but some activities may be optional. Understanding the impact of when to include optional (e.g. diaper changes), yet stress provoking interventions, will allow us to minimize overall environmental stress in hospitalized infants. Therefore, given the lack of research to inform best practices around the provision of bundled care, we sought to describe the type and sequencing of care provided during BCEs and explore the impact of bundling nurse caregiving on infant physiologic status. Specific research questions included:
- What factors impact the length of time required to complete a BCE.
- What is the relationship between activities included in BCEs and changes in infant physiological status (∆ heart rate, ∆ respiratory rate, ∆ oxygen saturation) during and following a BCE?
Methods:
A descriptive exploratory mixed-methods study was used to answer the research questions. The study was introduced to parents by the clinical providers and all parents consented to their infants’ study participation. Setting and sample: Preterm infants born at ≤32 weeks gestation were recruited from a 67-bed Level IV NICU. Data collection: Nurse caregiving activities were observed 2-4 times per week (n=351 observations) once infants were receiving enteral feedings every three hours. Observational data collection was initiated the first time the nurse entered the bed space and touched the infant and was stopped the last time the infant was touched following the last care activity. Each distinct care activity (e.g. abdominal girth, blood pressure, skin cleansing with a diaper change) was recorded including the total length of the BCE. The entire BCE was also evaluated and categorized as developmentally sensitive care, or not, by unit standards. Physiologic data (heart rate, respiratory rate, and oxygen saturation values) were downloaded from bedside monitors simultaneous with the observational data. The BCE start and stop times from the infant’s monitor were recorded to match with the physiologic data. Descriptive data to describe the sample were also collected from the electronic health record (EHR). Data analysis: Mixed effects growth curve models evaluated the impact of postmenstrual age in weeks (PMA), timing of the BCE (1st, 2nd, or 3rd, caregiving episode during the 12-hour shift), presence of a diaper change, and presence of developmentally sensitive caregiving (DSC) on the length of the BCE. The same model without the presence of a diaper change was used to evaluate factors impacting the length of the diaper changing event as an example of a routine but often optional care activity that is stressful to infants. A repeated measures Poisson regression model was used to estimate the number of caregiving activities in a BCE controlling for PMA, timing of the BCE, and presence of a diaper change and DSC. Visual analysis overlays of physiologic data with caregiving activities during bundled care were performed to evaluate the relationship between specific care activities and physiologic status.
Results:
Twenty-seven infants with a mean gestational age at birth of 27.9 weeks (SD=2.6) and a mean PMA at the time of initial data collection of 35.1 (SD=3.8) were recruited between January and October of 2018. The infants’ mean birthweight was 1101 grams (SD=401). The mean length of time it took to complete BCEs was 32.24 minutes (SD=14.04) for the initial caregiving episode of the 12-hour shift, 26.43 (SD=15.75) for the second, and 23.71 (SD=19.11) for the third. The length of time required to complete a BCE increased significantly over PMA (1.817 minutes per week; SE=0.432, p-value=<0.001). The mean number of caregiving activities in a BCE was 8.97 (SD=2.88). The initial caregiving episode in the 12-hour shift had almost one more activity than the 3rd episode and the 3rd episode had almost one more activity than the 2nd episodes (p-value=<0.001). Presence of a diaper change also significantly increased the length of BCEs; events with a diaper change lasted on average an additional 6.20 minutes (SE=2.284, p-value=0.007) longer than observations without a diaper change. The timing (1st, 2nd, or 3rd caregiving episode) of the BCE in the 12-hour shift also significantly impacted the length of the event. BCEs that occurred during the 2nd caregiving episodes were 1.74 minutes shorter than 3rd episodes, while the 1st caregiving episode was on average 3.61 minutes longer than the 3rd episode (p=0.021). Finally, DSC did not impact the length of BCEs.
One week of observations for four infants were purposively sampled to include the presence or absence of a diaper change or developmentally sensitive care thought to impact physiologic stress (n=14). Together infant physiologic status (HR, RR) changes from baseline were associated with the presence of specific stressful events such as diapering, repositioning, and inguinal hernia reduction. Oxygen saturation did not change from baseline. The time to return to the infant’s baseline status was variable, but BCEs greater than 30 minutes in length were associated with longer physiologic recovery times regardless of the number of care activities included in the BCE. Longer BCEs included breast and bottle feeding rather than tube feeding.
Conclusions:
To our knowledge this is the first study to characterize the entire BCE rather than single known stressful activities. More activities during the 1st BCE was expected given standard of care typically dictates the most thorough assessment at the beginning of a shift. Longer BCEs with oral feeding also appeared to decrease an infant’s ability to return to physiologic baseline (regulation), regardless of number of care activities completed in the event. Longer BCEs may lead to over stimulation delaying infants’ ability to return to baseline. While monitoring of respiratory status is common during oral feeding, our findings suggest that HR should also be monitored. Given that the presence of developmentally sensitive caregiving did not impact the length of BC, further examination is needed to understand how developmental interventions assist infants in promoting physiologic status.
The fact that all infants in our study were on every 3-hour enteral feedings limits our findings to stable infants. Younger and sicker preterm infants would likely have a different BCE profile. Future research will utilize Ecological Momentary Assessment methods to further examine the antecedent-consequence relationships between individual factors within BCE and preterm infant’s physiologic stress (Terhorst, Beck, McKeon, Graham, Ye, & Shiffman, 2017).