The results indicated that the mean gestational age of infants was 33.3 ± 2.2 weeks and the mean weight of newborns was 1871.2 ± 547.32 g. There was no statistically significant difference between the mean 1 and 5 minutes Apgar score and the mean number of venepuncture in the two groups [Table 1]. The fetal age of all subjects was 33 weeks.

Table 1: Frequency distribution of neonatal demographic variables in both intervention and control groups

The mean heart rate in both groups was initially found to be increased during venepuncture and then decreased over time (P <0.05), but the results showed that there is no significant difference between the mean heart rate at different times between the two groups (P> 0.05) [Table 2]

Table 2: Comparison of mean heart rate at different times between the two groups

The mean of respiratory rate in the intervention group was 59 and in the control group 58. Although the mean respiratory rate was higher in the intervention group, the results showed that there was no statistically significant difference in the respiratory rate over time in both groups (p> 0.05) [Table 3]

Table 3: Comparison of mean respiratory rate at different times between the two groups


The mean of arterial oxygen saturation in the intervention group was 94.875 and 94.7 in the control group. Although the mean of arterial oxygen saturation in the intervention group was higher, the results showed that there was no statistically significant difference in the mean arterial oxygen saturation during venepuncture in both groups (p> 0.05) [Table 4].

Table 4: Comparison of mean SP02 at different times between the two groups


There was no statistically significant difference between the mean pain intensity score in the neonates two minutes before the venepuncture and 30 minutes after the venepuncture between the intervention and control groups (p> 0.05). However, the mean score of pain in the intervention group was significantly less than the control group during the venepuncture and 5 minutes after the venepuncture (p <0.05) [Table 5].

Table 5: Comparison of mean pain intensity at different times between the two groups

There was no significant difference between the mean severity of stress and discomfort scores in the neonates two minutes before the venepuncture in two intervention and control groups (p = 0.13). However, the mean of stress and discomfort scores in the intervention group was significantly less than the control group during and 5 and 30 minutes after the venepuncture (p <0.05) [Table 6].

Table 6: Comparison of mean stress score at different times between the two groups

DISCUSSION

There are many studies worldwide about some of the environmental interventions (light and noise reduction), neonatal physiological and behavioral responses (heart rate, respiratory rate and arterial oxygen saturation) and various pain assessment methods, but no research has been found in relation to the effect of environmental and behavioral interventions on the physiological and behavioral responses of premature infants candidates for intravenous catheter insertion admitted to the neonatal intensive care unit. The results of this study showed that although the average heart rate in the two groups was different and was firstly increased during the venepuncture and was decreased over time, no significant difference was found between the mean heart rate at different times between the two groups. The mean respiratory rate and arterial oxygen saturation were higher in the intervention group, but these changes did not show a statistically significant difference in any of the two groups over time. The results of this study are in line with Marilyn’s study 2013 (29) in Canada as well as the study by Jacques Sizun (30) in France in 2002. The results of this study showed significant physiological changes (mean SpO2 and heart rate) among newborns with evolutionary care before and after weighing compared with the control group, but the rate of hypoxic attacks was decreased significantly, which was in line with the results of studies by Johnston et al. (31) and Taheri et al. (32) in 2007-2008. In terms of heart rate and respiratory rate, the results of this study were consistent with the study of Taheri et al., but did not have an agreement on the amount of arterial oxygen saturation. This discrepancy can be due to the difference between the procedures conducted in the study. The results of this study are consistent with the results of the study by Slevin et al. (33) in 2000. In addition, the results of this study are consistent with the results of the research by Abdeyazdan et al. (34) (2013), for the respiratory rate, but are inconsistent in terms of oxygenation rate. This discrepancy in outcomes can be attributed to the difference between the interventions in the study. The results of this study are not consistent with the results of the study by Celine Catelin and colleagues (35) in France in 2005. Their study showed that the implementation of environmental and behavioral interventions such as (closing baby’s eyes and ears, non-nutritious diet, kangaroo and family-centered care, shaking the baby and putting the baby in a fetal position) during the weighing process resulted in significant changes in physiological criteria; it suggests that these interventions have led to a decrease in respiratory rate and a decrease in heart rate, and an increase in arterial oxygen saturation, which can be due to the low number of samples in each group (15 neonates for each group). However in the recent study, increasing the number of neonates in each group (n = 41) as well as different procedures in the study could be the reasons for discrepancy in the results. Regarding the embryo’s position, the results of this study are not consistent with the results of the study by Reyhani et al. (2011) in Mashhad (36). This discrepancy can be attributed to individual differences, demographic characteristics of infants, providing different nursing care in infants’ intensive care units and different fetal age. Moreover, the results of this study are not consistent with the results of the study by Nasimi et al. (2014) in Mashhad (37). This discrepancy can be due to the different procedures conducted in the study; these studies have been done using an invasive procedure during a venepuncture, while the study by Nasimi et al., has been conducted with normal procedures in the ward. Other results obtained from this study also showed that there was no significant difference between the mean score of pain in newborns 2 minutes before venepuncture and 30 minutes after venepuncture between the intervention and control groups (p >0.05); but the mean score of pain in the intervention group was significantly less than that of the control group during and 5 minutes after the venepuncture (p <0.05). Additionally, there was no significant difference between the mean stress intensity and discomfort in the neonates 2 minutes before the venepuncture between the intervention and control groups (p = 0.13), but the mean score of stress and discomfort in the intervention group was significantly less than that of the control group during as well as 5 and 30 minutes after the venepuncture. The results of this study were in line with the results of the study by Celine Kathleen et al. (2005). Also, the results of this study are consistent with the results of the study of Reyhani et al. (2011) implying that the fetal position decreased the pain intensity of newborns in the intervention group compared to the control group.

CONCLUSION

According to the results, we can conclude that there are no environmental and behavioral interventions that affect the physiological and behavioral responses of the premature infant, so further research is recommended. Given the advantages of reducing pain and stress during the intravenous catheters insertion in premature infants, their low cost, the lack of specific equipment and the need for evolutionary care, it is recommended to use these interventions in order to decrease the pain of premature neonates during painful procedures including venpuncture.

Acknowledgement
The authors in this study would like to express their gratitude to the staff of the infant’s intensive care unit at Al-Zahra Hospital in Esfahan, who helped us carry out this research. This article is based on the results of a Master thesis of Nursing Special Babies, International Branch of Shahid Beheshti University of Medical Sciences.