Purpose: To determine the change in behavioral state and physiologic parameters due to Kangaroo Care (K Care). Method: A quasi-experimental design using a pretest-posttest with neonates serving as their own controls for 4 episodes of 1 hour each: Pre K Care, K Care and Post K Care. Twenty neonate-parent dyads participated. RespiTrace PT[R] Non-Invasive Monitoring system was used to record heart and respiratory rate and oxygen saturation. Behavioral state was derived from analyzing Respitrace PT cardiorespiratory data as well as observation criteria. Findings: There was a significant increase in sleep time for the neonates during K Care as compared to when they were not receiving K Care. The neonates exhibited less agitation, apnea, and bradycardia episodes and maintained stable oxygen saturation during K Care. Conclusion: K Care is safe even for very small neonates and is well tolerated. The stability of the preterm infants receiving K Care documents the need to incorporate it into standards of care.
Kangaroo Care (K Care) is becoming recognized as an important nursing intervention for preterm infants. K Care is the practice of holding a preterm infant, clothed only in a diaper, between the mother's breasts or against a father's bare chest skin-to-skin (Hamelin & Ramachandran, 1993). K Care was first introduced by Rey and Martinez (1983) in Bogota, Columbia, when a lack of single occupancy incubators increased infection rates among premature infants. The survival rates of these infants were encouraging in spite of their impoverished home environments. Due to the promising Columbian published reports, the nurses and physicians in "developed countries" saw the merit of evaluating long-term outcomes, survival rates, and health statuses of the Kangaroo Program (Anderson, Marks, & Wahlberg, 1986). K Care is now practiced in the NICU environment in Africa, Canada, Europe, South America, and United States. K Care has been demonstrated to be beneficial for neonates and ultimately to offer parents an opportunity to interact with their neonate more effectively. Therefore, a quasi experimental study was undertaken to determine the change in behavioral state and physiologic parameters related to K Care.
Review of Literature
K Care was started out of necessity in a developing country to promote positive neonatal health under adverse conditions. Research first focused on patient satisfaction. Parents expressed an increased sense of meaning, mastery, and self-esteem with their premature infants after participating in K Care (Affonso, Bosque, Wahlberg, & Brady, 1986; Affonso, Wahlberg & Person, 1989; Brooks, 1993). Parents loved K Care; they felt excitement and happiness, were no longer afraid of their infant's small size and fragility, and demonstrated a range of behaviors, such as looking at, talking to, and touching their infants (Anderson, 1991; Hosseini, Hashemi, & Lundington-Hoe, 1992). In Montreal, Quebec, K Care provided an opportunity for 71 mothers to hold their infants, which induced feelings of well-being and fulfillment (Legault & Goulet, 1995). American mothers (Anderson, 1991; Ludington-hoe, 1991; Wallace & Ridpath-Parker, 1993) as well as British (Whitelaw, Heiserkamp, Sleath, Acolet, & Richards, 1988), Dutch (De Leeuw, Colin, Dunnebier, & Mimiran, 1991) and African mothers (Colonna, Uxa, deGraca, & deVonderweid, 1990; Bergman & Jurisoo, 1994) reported improved lactation. The release of oxytocin was stimulated, triggering the let-down reflex, resulting in a positive effect on breast pumping, stimulating prolactin secretion, and improving milk production. Infants also greatly improved their suckling and swallowing abilities.
Parents reported confidence in their abilities to know and monitor their infants as K Care promoted parental attachment, even in cocaine-abusing parents who were at high risk for attachment impairments (Gale, Franck, & Lund, 1993). The benefits of K Care included: increased weight gain; less crying at six months of age; and enhanced mother-infant bonding with more frequent eye contact between parents and infant (Lundington-Hoe, 1990; Whitelaw, 1990). Quiet sleep frequency was increased, activity level reduced, and even in the presence of increased quantities of quiet sleep, less bradycardia episodes were noted and skin temperature was maintained in Lundington-Hoe's studies whose subjects had a mean gestational age from 28 weeks to 36 weeks (1990; 1992; 1994). In other studies, the post-conceptual age ranged from 26 weeks to full-term. Of the 140 infants participating in a Ecuador K Care study, readmissions were fewer and the cost of care was lower than the 160 infants in the control group (Sloan, Camacho, Rojas, Stern, & Ayora, 1994). in a Bogota, Columbia study, with 162 in the K Care group and 170 in the control group, K Care infants were discharged on average 4 days earlier than their matched control counterparts (Charpak, Ruiz-Palaez, & Charpak, 1994).
Collins (1993) indicated that K Care has a significant place in the care of high-risk neonates and should be practiced. Lundington-Hoe (1996) provided examples how K Care, as an intervention, modified the environment, individualized care to the infant, and promoted closeness and confidence in the parents. It is evident that participation in K Care is a global issue as documented by the review of literature.
Als (1986) Synactive Theory of Infant Development served as a basis for understanding preterm behavior. The infant's behavior is viewed as a subsystem of functioning; each subsystem can be described independently, yet functions in relation to the other sub-systems. This process of sub-system interaction or synaction is combined with the infant's continuous interaction with the parents and environment to formulate the synactive theory of infant development. The sub-system includes the autonomic, motor, state, attentional/interactional, and the self-regulatory systems.
In contrast to a full-term infant, the preterm infant has not yet reached the level of maturity or physiological functioning necessary to attain a balance of the sub-systems. Als, Lawhon, Duffy, McAnulty, Grossman, and Blickman (1994) stated that changing the NICU environment and using an approach of an individualized developmentally focused intensive care unit would reduce stress to the infant by helping them to improve their outcomes and attain sub-system balance. One such method to individualize care is K Care. K Care responds to the preterm neuro response or need for nurses' contact. It represents putting the concepts of individualization of care coupled with parent/infant interaction and self-regulation. Barnard (1984) proposed that conceptually functioning clustered investigations provide knowledge that can become the basis for nursing practice dealing with human responses to the health problems of prematurity. The developmental approach to nursing care of preterm infants provides significant benefits for the neonates and their families (Becker, Grunwald, Moorman, & Stuhr, 1991; Lawhorn & Melzar, 1988). Lotus and Walden (1996) documented significant benefits of individualized developmental care. Therefore, it is felt that using K Care as a nursing intervention should have a positive impact on these infants by supporting their own efforts toward self-regulation and competent functioning.
In one metropolitan medical center NICU, parents frequently expressed a lack of confidence in handling and caring for their preterm infants at the time of discharge. The neonatal nurses hypothesized that close parent/infant skin-to-skin contact provided by the K Care program would enhance parenting skills; ultimately improving neonatal outcomes. However, the unit's neonatologists expressed a concern about the lack of documented research supporting the physiological stability of very low birth weight infants during K Care. Thus, a collaborative study between nursing and medicine implementing the K Care concept was initiated with neonates and their families.
The purpose of this quasi-experimental research study was to determine if the use of a nursing intervention, termed K Care, would result in changes in infants' behavioral state and other physiologic parameters. The study addressed the influence of K Care upon parental stress, emotional effects, and attitudes towards their infant and described the relationship of age, culture, education, gravida, and socioeconomic status of parents to their acceptance of K Care.
1. Do frequency and duration of behavioral state differ during K Care as compared to the Pre-K Care and Post-K Care periods?
2. Do cardiorespiratory parameters such as heart rate, respiratory rate, arterial oxygen saturation, and number of episodes of bradycardia and apnea differ during K Care as compared to Pre- and Post-K Care episodes?
3. How does K Care affect parental stress, emotional affect, and attitudes toward the baby?
4. Is there a relationship between parent characteristics (age, culture, education, parity and socioeconomic status) and their acceptance of K Care?
Design. This quasi-experimental study compared 20 participating infants to themselves and between subjects for four episodes of 1-hour sessions of each Pre-K Care, K Care and Post-K Care periods. For the parent component of the study, a nonequivalent control pretest-posttest design was used. The parents were administered the parent-infant bonding instruments prior to participating in the first episode of K Care and after participating in the last episode of K Care.
Setting. This prospective study was conducted in an 8-bed neonatal intensive care unit (NICU) at a 707-bed academic medical center in South Florida. The study was approved by the institutional Review Board prior to the start. All parents signed a consent form.
Sample. A sample was recruited from parents with a preterm infant in a Level II NICU. Thirty parents were asked to participate in the study; subject participation was on a voluntary basis. Two parents chose not to participate because of the time commitment and 8 parent/infant dyads did not complete all four episodes, again due to time constraints as they were working parents. Thus 20 dyads completed all four episodes. Power analysis computations suggested that a sample size of 20 per group is adequate for detecting a large effect size ranging from .80 to .90 when testing for a difference between the groups with power = .80 at alpha equals .05. These computations are based on a t-test using a power analysis (Cohen, 1977).
Inclusion criteria for the infants included: Postgestational age at time of study of 26-37 weeks; birth weight between 750 and 1500 grams; 5 minute Apgar scores of 6 or more; stable body temperature and vital signs in the last 48 hours; NPO with IVs, gavage feedings, and breast or bottle feeding every 2-3 hours. Exclusion criteria for infants consisted of-. mechanical ventilation requiring labile ventilator support (highly variable [FiO.sub.2] needs, frequent ventilator changes; [O.sub.2] requirements greater than 50%); chest tubes; peripheral arterial lines; and temperature decrease during K Care by more than one degree from the infant's baseline temperature.
Inclusion criteria for the parents were: ability to devote a block of time for the project and willingness to participate. Exclusion criteria for parents were absence of any infection and relinquishing the infant for adoption.
Survey instrument. A questionnaire developed by the research team and subjected to face validity requesting information about age, gender, marital status, educational level, socioeconomic status, cultural background, and occupation was administered to parent volunteers. In addition, type of delivery and maternal obstetrical history were obtained from the medical records. Data for the infant were taken from the Medical Record and Birth Certificate Record which included Apgar scores #1 (1 minute) and #2 (5 minutes), and gestational and post conceptual age.
The RespiTrace PT Monitoring System. The RespiTrace PT[R] Monitoring System (Nims, Miami Beach, FL) was used to record cardiopulmonary variables. Respitrace FIT measures respiration using a calibrated inductive plethmography method. Two nonconstrictive bands are applied, one each on the abdomen and over the chest. This device is able to detect central, mixed and obstructive apnea or hypopneas (Adams, Inman, Abreu, Zabaleta, & Sackner, 1995; Adams, Zabaleta, & Sackner, 1995; Adams, Zabaleta, Stroh, & Sackner, 1995; Adams, Zabaleta, Stroh, & Sackner, 1993). RespiTrace PT also monitors and records the electrocardiogram (EKG), arterial saturation ([SaO.sub.2]), and its plethymorgraphic pulse wave. The digital data were collected at a sample rate of 50 Hz for respiration and 250 Hz for EKG. The data were stored on a hard drive and off-line analysis of the data were performed using Event Display Program (EDP, Nims, Miami Beach, FL) (Adams, 1992).
Behavioral states are defined using cardiorespiratory parameters as observation criteria (Brazelton, 1994). Quiet sleep is defined as the infant's eyes are firmly closed and still. There is little or no motor activity, with the exception of occasional startles or rhythmic mouthing. Respiration is slow and regular, with little variability. Active sleep is characterized with the infant's eyes closed with rapid eye movement (REM) occurring during a 10-second interval. Body activity can range from minor twitches to writhing and stretching. Respiration is irregular, primarily abdominal with rib cage and abdominal paradoxical motion, and generally faster than seen in quiet sleep (average, 46 breaths/minute). Facial movements may include frowns, grimaces, smiles, twitches, mouth movements, and sucking. Awake time includes drowsy state, alert inactivity, fussing, and crying. In the drowsy state, the infant's eyes may open and close or may be partially or fully open, but they are still and appear dazed. There may be some generalized motor activity, and respiration is fairly regular, but it is faster and more shallow than that observed in regular sleep. In alert inactivity, the infant's body and face are relatively quiet and inactive, and the eyes appear bright and shining. Fussing has mild, agitated vocalizations that are continuous, or one cry burst may occur. In crying, generalized motor activity is more intense, and cry bursts are continuous (Brazelton, 1994).
Parent/infant interaction Instruments. The parent's attitude, stress, and emotional affect were measured by 3 scales. 1. The Attitudes toward Babies Scale, which measured the parent's attitudes toward their infant. This semantic differential scale consisted of 11 bipolar adjectives such as sweet-sour, strong-weak, peaceful-belligerent. Alpha reliability was reported at .78 (Coffman, Levitt, & Deets, 1991). 2. A modified version of Lazarus's Hassles Scale measured the parent's appraisal of stress in the form of daily hassles. This 50-item scale reported an Alpha reliability of .91 and .93 (Kanner, Coyne, Schaefer, & Lazarus, 1981). 3. Bradburn's Emotional Affect Scale, a 10 item scale, measured emotional affect. This dichotomous scale reported an Alpha reliability of .63 (Bradburn, 1969).
These scales were translated into Spanish for this study by a member of the research team (not a nurse) who was of Cuban descent; however, the tools were critiqued by an authorized and certified Spanish translator who is employed at a professional translating company. Parents participating selected either the English or Spanish version.
A questionnaire eliciting information and the instruments -- Attitudes Toward Babies Scale, Lazarus's Hassles Scale, and Bradburn's Emotional Affect Scale -- were administered prior to starting the initial K Care episode. The parents were resurveyed after completing four K Care episodes. Parents were instructed to arrive currently bathed or showered, and wearing no perfume or cologne. Following routine hand scrub, mothers unbuttoned their front buttoning shirt, removed their bra, voided, and if breast-feeding, pumped their breast if necessary prior to K Care for maximal comfort. Fathers washed their hands and unbuttoned or removed their shirt. The parent was placed in a reclining chair with a foot rest. During the Pre- and Post-K Care periods, the infant was placed in the incubator in a prone position at a 30-degree angle. The nurse removed all the clothing from -the infant except for a diaper placed bikini style. The skin temperature probe was attached to the infant's left flank (Mercury Medical Thermistor). EKG electrodes were placed: two on either lateral chest walls and one on a leg. During the K Care period, the infant was placed upright skin-to-skin between the mother's breast or on the father's chest for the K Care episode, which lasted for 1 hour. The infant and parent were covered with 1 receiving blanket to improve insulation and prevent heat loss. Lights around the bedside were dimmed when possible and a privacy screen was provided for the parent/infant, since K Care took place on the open unit.
RespiTrace PT was used to continuously monitor and record physiological data for all three K Care sessions. All mother and infant behavior was recorded including the beginning and ending times for incubator session for the Pre-, Post-, and K Care sessions; feedings; and Side Arm Nebulizer (SAN). Change in oxygen requirements as measured by pulse oximeter; skin temperature as measured by thermistor; and any verbal/tactile stimulation to infant by parent or staff were noted, as were any significant ICU activity (which might disturb couplet) and administration of medication, including phenobarbital, aminophylline, caffeine, and ferrous sulfate (dose, frequency, time). Because interventions are known to alter vital signs for up to five minutes, nursing intervention data was correlated with changes in heart and respiratory rates and [SaO.sub.2]. All interactions with the infant, physical or verbal, were recorded by a member of the research team who were trained by the nurse clinician. Data were collected over no more than 4 consecutive days.
Twenty parent/infant dyads participated in the study. Demographic data including age, gender, income, and educational levels, of the 20 parents who completed all four episodes are presented in Table 1.
Eight parent/infant dyads did not complete all four episodes and were eliminated from the data analysis. Of the remaining parents, the fathers were older than the mother by an average of seven years. The median income was $25,000 for the mother and $35,000 for the father, while the education level revealed an average of one year of college. The source of payment was private insurance and Medicaid. Gravida, parity status, and type of delivery of the mothers reported are: number of pregnancies averaged 1.6, while the number of siblings averaged 2-3 including the study; and there was an equal number of vaginal and cesarean deliveries (see Table 1). This represents the composite of the parent/preterm infant patient population at the medical center.
Demographic data on cultural background of the parents presented in Table 2.
The cultural background reflects the population diversity served by the facility and is fairly even in Black, Caucasian, and Hispanic clients with a fewer number of Asian parents participating.
Demographic data of the 20 preterm infants are presented in Table 3.
There were 11 (55%) female and 9 (45%) male infants participating. The mean average birth weight was 1315 gms. The mean average gestational age was 28 weeks, while the mean average post-conceptual age at the time of the study was 30 weeks. The Apgar score averaged 6.8 at 1 minute and 7.8 at 5 minutes.
Analysis of behavioral states were performed for each period and are shown in Table 4.
Each infant subject was compared with their Pre-K Care and Post K Care period and finally the data were pooled for all subjects., Analysis of variance for within subjects and pooled differences procedures showed a P value of [is less than].05, which was statistically significant. Analysis of the data indicated a significantly greater percentage of quiet sleep during K Care as compared to the times when not receiving K Care (see Table 4). A greater difference in the quiet sleep was more evident in the first episode of the Pre K Care, K Care, and Post K Care than the other three later time periods. Analysis of the data using one- way repeated measures ANOVA procedures followed by post-hoc tests of significance with Student Neuman Keuis procedure were applied to mean scores and percentages of the physiological measurements. There was also a significant decrease in awake time during the K Care period (see Table 4). There was a mean increase in Active Sleep from the Pre K Care to K Care; this did not reach statistical significance (see Table 4). The findings of greater quiet sleep and decreased awake time were based upon behavioral and cardiorespiratory recording during the intervention.
Analysis of median heart rate, respiratory rate, and [SaO.sub.2] were performed for each period. The findings for the heart rate, respiratory rate and [O.sub.2] saturations are found in Table 5.
The findings were not statistically significant since most infants maintained stable [O.sub.2] saturations and experienced few episodes of apnea and bradycardia during each period. These findings support the research of Bauer and associates (1996). A limitation of this study may be the grouping of all parameters within an entire study period.
Although the data analyses of the measures for parent/infant bonding indicated a trend in the positive direction, they were not significant see Table 6.
This lack of significance could be attributed to the instruments being developed in English and translated to Spanish by non-nurses for the purpose of this study. Perhaps in the translation, the words may have had different interpretations. Since there were no prior studies reported using these instruments in this diverse cultural population sample, the meanings of the statements to the participants could be different.
This study indicated that infants receiving K Care had longer and deeper sleep time. The results indicated a significant increase in quiet sleep time for those infants during K Care as compared to the times when they were not receiving K Care. This study supports Lundington-Hoe's study of 8 preterm infants who experienced twice as much quiet sleep in K Care, as Pre K Care and Post K Care. Quiet sleep, characterized by regular respirations, is important because central and mixed obstructive apnea occur less frequently during this stage of sleep. During this study, feeding times were not controlled and occurred at various times during the study period as compared to Lundington-Hoe's control of feeding times and collecting data for 9-12 hours (Lundington-Hoe & Kasper, 1995). The variability in feeding times may have detracted from the length of the sleep intervals. At times, a gavage feeding was provided during the session. At no time, however, was any one hour session interrupted for bottle or breast feeding. Feeding times were equally distributed among the three periods. Determination of the effect of sleep and wakefulness in heart rate, respiratory rate, and [O.sub.2] saturation can only be made when there is enough time to observe the emergence of different states. Therefore, larger study periods and a larger sample may be necessary to study these effects. Future research on cardiorespiratory parameters should also include those infants with a more labile ventilatory status.
The measures for parent/infant bonding were not clinically significant and additional research is warranted to determine if the instruments are culturally sensitive and/or translated accurately for content. K Care provided close parental-infant contact and the parents expressed more confidence at the time of discharge. This finding concurs with Colonna's study (1990) that K Care was instrumental in developing early mother-infant relations. Parents reported feeling more comfortable assuming responsibility in caring for their infants and at ease taking their infants home after participating in K Care. Parents related greater ease in assuming care tasks such as diaper change, handling, and taking of the infant's temperature as compared to prior to participating in the K Care experience. As a result of K Care, one mother gained the confidence to learn to gavage feed her infant and continued to successfully gavage feed the infant at home. A content analysis of the parents' comments revealed common themes of confidence, optimism, and final acceptance of the preterm infant after K Care experience (Messmer, Rodriguez, Wells-Gentry, & Washburn, 1995). One mother expressed the feeling that after K Care she finally accepted the infant as her own and was able to purchase the baby clothes and baby care supplies. One father in the study stated that although his infant's care was considered high-tech, the K Care was more high-touch; thus, he could really "bond" with his infant.
Although comparing the length of stay (LOS) for the infants participating in the study versus the LOS of the NICU infants during the same period who did not participate was not part of the original study, these data were reviewed. The LOS in the NICU for the preterm infants receiving K care was not significantly lower than the infants who did not participate. It should be pointed out that in many cases the infants participating in K Care were smaller in birth weight, and more acutely ill which necessitated longer LOS. This finding differs from Anderson's (1986) and Lundington-Hoe's (1990) accounts that these infants tend to gain weight at a faster rate while participating in K Care and are discharged sooner.
This patient population represented a diversity in cultural and ethnic background, a cross section of educational levels and various methods of payments. There have been no studies that have documented if parents from the different cultures react in unique and different ways to the K Care project. In our observations, some Hispanic mothers initially were less receptive to the idea, in part they were concerned about unbuttoning their blouses. After it was explained that a privacy screen would be provided, most mothers agreed to participate. Several parents who initially declined asked if they could participate after they watched another parent participating in the project. The parents overcame the feelings of their infants being in a "high technology" environment and K Care became a popular topic of discussion among the parents. Nursing implications are that preterm infant care should include parent-infant skin-to-skin contact; thus they become a family unit prior to discharge. Since the findings of this study demonstrated that during the K Care period, the preterm infants had longer and deeper sleep periods, future research should focus more closely on the sleep status of preterm infants. This could be accomplished by including Electroencephalogram (EEG) monitoring of the infants. An hour block of K Care time may be not long enough to evaluate the physiological parameters; therefore, it is recommended that a longer period of time and an increase number of episodes be implemented for K Care, using 2 to 3 hour blocks over 1 to 2 week periods. Because of the possibilities that the infant's sleep patterns may be interrupted when gavage feedings or respiratory treatments are administered, these activities should be scheduled between sessions.
This study provides evidence that K Care is safe even for very small neonates and is well tolerated by the neonates and families. Findings of this study demonstrated that during K Care, preterm infants had longer and deeper sleep periods thus improving their physiological status. It is expected that improved physiological and sleep measures will foster greater weight gain, enabling these infants to attain a discharge weight of 2200 gms sooner by participating in K Care. Although Charpak (1994) reported that K Care infants were discharged on average 4 days earlier than their counterparts; in this study the LOS was not decreased. Perhaps because in many cases, the participating neonates under study were lower in birth weight and sicker than the nonparticipating neonates. Since K Care increases parents' comfort level in caring for their preterm infants, LOS may be reduced in a prospective study as LOS and earlier discharges should be analyzed more closely in a matched comparison group. The stability of preterm infants receiving K Care documents the need to incorporate K Care as a standard for nursing practice. This project also demonstrated the impact that a collaborative research project in nursing and medicine can have in influencing nursing practice.
Editor's Note: This project was presented as a poster at: 1994 Sigma Theta Tau International (STTI) Australian Congress, 1995 AJN Maternal-Child Conference, and the 1995 33rd Biennial STTI convention in Detroit, MI. The project was presented as a paper at the 1995 World of the Hospitalized Child Conference and the 1996 STTI Jamaican Congress in Ochos Rio, Jamaica.
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Patricia R. Messmer, PhD, RNC, is Director of Nursing Research at Mount Sinai Medical Center, Miami Beach, FL.
Suzanne Rodriguez, BSN, RN, CCRN, was the NICU Nurse Clinician at the time of the study, but is now the nurse manager, nursery at Health South, Doctors Hospital, Miami, FL.
Jose Adams, MD, is a NICU Neonatologist at Mount Sinai Medical Center, Miami Beach, FL.
Joyce Wells-Gentry, MS, RN, is the evening administrator at Mount Sinai Medical Center, Miami Beach, FL.
Kathy Washburn MSN, RNC, is the NICU Nurse Manager at Mount Sinai Medical Center, Miami Beach, FL.
Iganacio Zabaleta, MD, is a NICU Neonatologist at Mount Sinai Medical Center, Miami Beach, FL.
Sonia Abreu, BS, CCRT is the Research Assistant to Drs. Adams and Zabaleta, at Mount Sinai Medical Center, Miami Beach, FL.