Original Article Evaluation of Pain in Healthy Newborns and in Newborns with Developmental Problems (Down Syndrome) Maria Jos e Aguilar Cordero, PhD,* Norma Mur Villar, PhD,† and Inmaculada Garcıa Garcıa, PhD‡
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From the *Department of Nursing, Faculty of Healthcare Science, University of Granada, Granada, Spain, Nurse at the San Cecilio University Hospital of Granada, Spain; †University Medical of Cienfuegos, Cuba, Research Assistant at Research Group CTS 367, Andalusian Research Plan, Andalusian Regional Government, Spain; ‡Department of Nursing, Faculty of Healthcare Science, University of Granada, Granada, Spain. Address correspondence to Maria Jose Aguilar Cordero, PhD, Universidad de Granada, Departamento de Enfermerıa, Facultad de Ciencias de la Salud, Av/ Madrid s/n - CP: (18071), 18071 Granada, Spain. E-mail: mariajaguilar@telefonica. net Received June 4, 2014; Revised July 31, 2014; Accepted August 4, 2014. In this study, there is no conflict of interest concerning the financial support received or concerning the relationship of any of the authors. 1524-9042/$36.00 Ó 2015 by the American Society for Pain Management Nursing http://dx.doi.org/10.1016/ j.pmn.2014.08.001
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ABSTRACT:
Newborns are often subjected to invasive and painful medical procedures. This happens even more frequently when they require hospitalization. The aim of this paper was to evaluate pain in healthy newborns and in newborns with Down syndrome (DS). We performed a prospective cohort study in the neonatal service of the San Cecilio University Hospital in Granada (Spain) from January 2008 to September 2013. The universe of our study comprised a study group of 20 newborns with DS and a control group of 20 newborns without DS. All of the infants were hospitalized, and thus had to undergo painful medical procedures. The variables studied were basal recovery time (as reflected in crying and the normalization of biological constants), number of punctures, oxygen saturation, heartbeat, blood pressure, response to skin-to-skin contact, and gestational age. The evaluation was performed during blood extraction, vein canalization, and heel puncture. The significant differences in the basal recovery time between the two groups of newborns indicated that those with DS were slower to express pain, and when they did, their response was not as clearly defined as that of babies without DS. The oxygen saturation in babies with DS after the puncture was found to be significantly lower than that of the control group (p < .001). The results of this study revealed that babies with DS were not as quick to perceive pain after a puncture. However, when pain was finally perceived, it persisted for a longer time. This situation should be taken into account in the design of pharmacologic and nonpharmacologic therapies. Ó 2015 by the American Society for Pain Management Nursing
Pain Management Nursing, Vol 16, No 3 (June), 2015: pp 267-272
268
Aguilar Cordero, Mur Villar, and Garcıa Garcıa
BACKGROUND The assessment of pain in newborns is a priority for health professionals. It is now known that infants feel pain more intensely than individuals at other stages of life. However, because of their lack of verbalization and expression, it was once thought that newborns were less sensitive to pain. Fortunately, this has changed, and there is now a great known about the neurophysiological mechanisms of neonatal pain (Allegaert et al., 2005; Belieni, Bagnoli, & Buonocore, 2003). A study published in The Lancet proposed that impaired perception of pain in babies with Down syndrome (DS) is not due to a delay in the transmission of pain but to a cognitive deficiency. Thus, it indicates that pain in these babies is associated with impaired peripheral somatosensitive nerve function. Finally, monitored transmission showed a delay in the subjective expression of pain after a painful sensory stimulus (Cehn & Fang, 2005). Currently, pain prevention is an essential part of neonatal care, not only for its ethical implications, but also because of the painful stimuli that newborn babies experience in pediatric units. Such painful stimuli are accentuated in preterm and critically ill newborns because they must endure numerous diagnostic and therapeutic procedures (Cehn & Fang, 2005; Craig, 1998; Cua, Blankenship, North, Hayes, & Nelin, 2007; Delfrin, Petretz, & Carmeli, 2004; Fitzgerald & Beggs, 2001). Infants with DS perceive pain differently than healthy infants do. In 2011, a group of researchers presented a scale designed to assess the behavior of 0- to 3year-old infants with DS in pain and demonstrated that the scale effectively evaluated distress and discomfort (Fitzgerald & Beggs, 2001). Endogenous opioids such as b-endorphin, enkephalins, and dynorphins are pain-perception inhibitors. There are also other neurotransmitters involved in the reduction of pain perception, such as serotonin and g-aminobutiric acid (GABA) (Fonseca et al., 2008). Pain perception in newborns is different from pain perception in other stages of life. The difference lies in its neurophysiology. Nociceptive impulses travel upward through nonmyelinized paths resulting in a relatively negative neurotransmission capacity. Newborns may have higher concentrations of P-substance receptors and lower excitation and sensitization thresholds. This would lead to higher nociceptive stimuli, all of which would result in a more severe pain sensation in infancy than in other life stages. Another study demonstrated that children with DS are not insensitive to pain, but that they express it differently
(Harrison, Evans, & Johnston, 2002; Hennequin, Faulks, & Allison, 2003). Other research measured pain by using both the limit method to assess reaction, and the level method. The results indicated that children with DS were more sensitive to pain than the rest of the population (Fitzgerald, 1995; Jessop, 2001). Nevertheless, there are also studies showing that increased concentrations of opioids with analgesic activity, such as leuenkephalin and dynorphin, affect children’s physiological responses and increase their pain threshold, meaning that children with DS may be less sensitive to pain (Cua et al., 2007; Hennequin et al., 2003; Krechel & Bildner, 1995). The aim of this study was to compare pain in healthy newborns with babies with developmental problems (i.e., DS) during painful medical procedures.
METHODS A prospective cohort study was carried out at the neonatal care unit of the San Cecilio University Hospital, in Granada between January 2008 and September 2013. The population for the study consisted of 20 newborns with DS as the case group, and 20 newborns without DS as the control group. All the infants were hospitalized and had to experience painful procedures. Variables, such as basal recovery time, were assessed based on crying and the normalization of biological constants. Other variables included number of punctures, oxygen saturation, heartbeat, blood pressure, response to skin-to-skin contact, and gestational age. Babies were placed near their mothers during the puncture, and all these variables were analyzed 1 minute before the procedure (baseline) and 1 and 2 minutes after post-puncture according to the protocol. Pain assessment was carried out in all babies whose parents had previously given their informed consent. A pain rating scale was used to assess pain in term and preterm newborns during painful medical procedures (Aguilar, 2012; Table 1). For the validation of the questionnaire, 30 experts were asked to rate the relevance of each item. To ascertain the degree of adequacy of the scale items, we calculated the percentage of experts who found each item to be relevant. Subsequently, the percentages obtained were added up and divided by the highest value, which was obtained when all items were considered relevant by all of the experts. The value obtained was 0.775, which indicated the validity of the scale. Data processing was performed with the c2 and Student’s t tests, considering as significant p < .05.
Pain in Newborns
269
TABLE 1. VADONE (Assessment Pain Newborn) Scale. Assessment Scale of Pain in the Term and Preterm Newborn During Painful Procedures
For the questionnaire assessment we employed the criteria of 30 judges to assess every item as appropriate or inappropriate for the scale. To find the level of adequacy of the scale items we calculated the number of judges who assessed each item as correct. Subsequently, the percentages obtained were added up and divided by the highest value, if all items were considered adequate by all judges. The obtained value was 0.775, which indicates a high validity of the scale. Therefore, we can consider that the questionnaire is sufficiently valid, according to the validation procedure employed.
This research was approved by the Ethics Committee of the San Cecilio University Hospital of Granada. Parents of all of the babies signed a form authorizing the participation of their children in the study.
RESULTS AND DISCUSSION Figure 1 depicts the significant differences found between infants with DS and those without DS in terms of the time elapsed until return to normal physiological conditions after puncture. However, this figure only includes the categories of baseline recovery time after crying, time to normalization of biological constants, and oxygen saturation levels. Statistically significant differences were found between healthy
babies and babies with DS in their baseline recovery time. It was found that the babies with DS took longer to recover after a puncture than control group. In this regard, different authors have suggested that patients with DS do not always show signs of pain or distress after a painful stimulus, when compared with the general population. Other authors agree that children with DS have limited ability to express their reaction to a painful stimulus by means of behavioral signs (Mafrica, Schifilliti, & Vincenzo, 2006). Hennequin et al. (2003) performed a pilot study to measure the capacity of people with DS to detect and express painful sensations in comparison with volunteers without DS. The results showed that individuals with DS were not insensitive to pain. However, they
270
Aguilar Cordero, Mur Villar, and Garcıa Garcıa
TABLE 2. Mean Values (and SD) and Significant Values for Down Syndrome and Gestational Age Factors at Birth Down Syndrome Term (n ¼ 15)
Preterm (n ¼ 5)
Healthy Term (n ¼ 14)
Preterm (n ¼ 6)
Baseline oxygen saturation 95.7% (2.7%) 96.6% (0.9%) 98.1% (1.6%) 98% (1.3%) Oxygen saturation after 89.7% (3.8%) 87.0% (6.2%) 96.4% (1.2%) 96.0% (0.6%) intervention Baseline heart rate 144.9 (7.0) 152.4 (4.6) 137.1 (5.9) 145.0 (5.9) Heart rate after intervention 165.2 (10.3) 174.2 (5.9) 158.1 (9.1) 163.0 (8.5) Maximum baseline blood 79.8 (4.4) 76 (1.6) 82.6 (7.3) 75.5 (3.7) pressure Maximum blood pressure after 87.1 (5.1) 84 (5.5) 89.9 (6.8) 87.0 (6.8) intervention Minimum baseline blood 52.5 (4.2) 51.2 (5.4) 52.9 (6.8) 44.8 (4) pressure Minimum blood pressure after 53.3 (5) 52.4 (4.3) 56.9 (6.4) 53 (5.1) intervention
ANOVA 2-Ways p Down Syndrome Gestational Factor Age Factor .011
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From the *Department of Nursing, Faculty of Healthcare Science, University of Granada, Granada, Spain, Nurse at the San Cecilio University Hospital of Granada, Spain; †University Medical of Cienfuegos, Cuba, Research Assistant at Research Group CTS 367, Andalusian Research Plan, Andalusian Regional Government, Spain; ‡Department of Nursing, Faculty of Healthcare Science, University of Granada, Granada, Spain. Address correspondence to Maria Jose Aguilar Cordero, PhD, Universidad de Granada, Departamento de Enfermerıa, Facultad de Ciencias de la Salud, Av/ Madrid s/n - CP: (18071), 18071 Granada, Spain. E-mail: mariajaguilar@telefonica. net Received June 4, 2014; Revised July 31, 2014; Accepted August 4, 2014. In this study, there is no conflict of interest concerning the financial support received or concerning the relationship of any of the authors. 1524-9042/$36.00 Ó 2015 by the American Society for Pain Management Nursing http://dx.doi.org/10.1016/ j.pmn.2014.08.001
-
ABSTRACT:
Newborns are often subjected to invasive and painful medical procedures. This happens even more frequently when they require hospitalization. The aim of this paper was to evaluate pain in healthy newborns and in newborns with Down syndrome (DS). We performed a prospective cohort study in the neonatal service of the San Cecilio University Hospital in Granada (Spain) from January 2008 to September 2013. The universe of our study comprised a study group of 20 newborns with DS and a control group of 20 newborns without DS. All of the infants were hospitalized, and thus had to undergo painful medical procedures. The variables studied were basal recovery time (as reflected in crying and the normalization of biological constants), number of punctures, oxygen saturation, heartbeat, blood pressure, response to skin-to-skin contact, and gestational age. The evaluation was performed during blood extraction, vein canalization, and heel puncture. The significant differences in the basal recovery time between the two groups of newborns indicated that those with DS were slower to express pain, and when they did, their response was not as clearly defined as that of babies without DS. The oxygen saturation in babies with DS after the puncture was found to be significantly lower than that of the control group (p < .001). The results of this study revealed that babies with DS were not as quick to perceive pain after a puncture. However, when pain was finally perceived, it persisted for a longer time. This situation should be taken into account in the design of pharmacologic and nonpharmacologic therapies. Ó 2015 by the American Society for Pain Management Nursing
Pain Management Nursing, Vol 16, No 3 (June), 2015: pp 267-272
268
Aguilar Cordero, Mur Villar, and Garcıa Garcıa
BACKGROUND The assessment of pain in newborns is a priority for health professionals. It is now known that infants feel pain more intensely than individuals at other stages of life. However, because of their lack of verbalization and expression, it was once thought that newborns were less sensitive to pain. Fortunately, this has changed, and there is now a great known about the neurophysiological mechanisms of neonatal pain (Allegaert et al., 2005; Belieni, Bagnoli, & Buonocore, 2003). A study published in The Lancet proposed that impaired perception of pain in babies with Down syndrome (DS) is not due to a delay in the transmission of pain but to a cognitive deficiency. Thus, it indicates that pain in these babies is associated with impaired peripheral somatosensitive nerve function. Finally, monitored transmission showed a delay in the subjective expression of pain after a painful sensory stimulus (Cehn & Fang, 2005). Currently, pain prevention is an essential part of neonatal care, not only for its ethical implications, but also because of the painful stimuli that newborn babies experience in pediatric units. Such painful stimuli are accentuated in preterm and critically ill newborns because they must endure numerous diagnostic and therapeutic procedures (Cehn & Fang, 2005; Craig, 1998; Cua, Blankenship, North, Hayes, & Nelin, 2007; Delfrin, Petretz, & Carmeli, 2004; Fitzgerald & Beggs, 2001). Infants with DS perceive pain differently than healthy infants do. In 2011, a group of researchers presented a scale designed to assess the behavior of 0- to 3year-old infants with DS in pain and demonstrated that the scale effectively evaluated distress and discomfort (Fitzgerald & Beggs, 2001). Endogenous opioids such as b-endorphin, enkephalins, and dynorphins are pain-perception inhibitors. There are also other neurotransmitters involved in the reduction of pain perception, such as serotonin and g-aminobutiric acid (GABA) (Fonseca et al., 2008). Pain perception in newborns is different from pain perception in other stages of life. The difference lies in its neurophysiology. Nociceptive impulses travel upward through nonmyelinized paths resulting in a relatively negative neurotransmission capacity. Newborns may have higher concentrations of P-substance receptors and lower excitation and sensitization thresholds. This would lead to higher nociceptive stimuli, all of which would result in a more severe pain sensation in infancy than in other life stages. Another study demonstrated that children with DS are not insensitive to pain, but that they express it differently
(Harrison, Evans, & Johnston, 2002; Hennequin, Faulks, & Allison, 2003). Other research measured pain by using both the limit method to assess reaction, and the level method. The results indicated that children with DS were more sensitive to pain than the rest of the population (Fitzgerald, 1995; Jessop, 2001). Nevertheless, there are also studies showing that increased concentrations of opioids with analgesic activity, such as leuenkephalin and dynorphin, affect children’s physiological responses and increase their pain threshold, meaning that children with DS may be less sensitive to pain (Cua et al., 2007; Hennequin et al., 2003; Krechel & Bildner, 1995). The aim of this study was to compare pain in healthy newborns with babies with developmental problems (i.e., DS) during painful medical procedures.
METHODS A prospective cohort study was carried out at the neonatal care unit of the San Cecilio University Hospital, in Granada between January 2008 and September 2013. The population for the study consisted of 20 newborns with DS as the case group, and 20 newborns without DS as the control group. All the infants were hospitalized and had to experience painful procedures. Variables, such as basal recovery time, were assessed based on crying and the normalization of biological constants. Other variables included number of punctures, oxygen saturation, heartbeat, blood pressure, response to skin-to-skin contact, and gestational age. Babies were placed near their mothers during the puncture, and all these variables were analyzed 1 minute before the procedure (baseline) and 1 and 2 minutes after post-puncture according to the protocol. Pain assessment was carried out in all babies whose parents had previously given their informed consent. A pain rating scale was used to assess pain in term and preterm newborns during painful medical procedures (Aguilar, 2012; Table 1). For the validation of the questionnaire, 30 experts were asked to rate the relevance of each item. To ascertain the degree of adequacy of the scale items, we calculated the percentage of experts who found each item to be relevant. Subsequently, the percentages obtained were added up and divided by the highest value, which was obtained when all items were considered relevant by all of the experts. The value obtained was 0.775, which indicated the validity of the scale. Data processing was performed with the c2 and Student’s t tests, considering as significant p < .05.
Pain in Newborns
269
TABLE 1. VADONE (Assessment Pain Newborn) Scale. Assessment Scale of Pain in the Term and Preterm Newborn During Painful Procedures
For the questionnaire assessment we employed the criteria of 30 judges to assess every item as appropriate or inappropriate for the scale. To find the level of adequacy of the scale items we calculated the number of judges who assessed each item as correct. Subsequently, the percentages obtained were added up and divided by the highest value, if all items were considered adequate by all judges. The obtained value was 0.775, which indicates a high validity of the scale. Therefore, we can consider that the questionnaire is sufficiently valid, according to the validation procedure employed.
This research was approved by the Ethics Committee of the San Cecilio University Hospital of Granada. Parents of all of the babies signed a form authorizing the participation of their children in the study.
RESULTS AND DISCUSSION Figure 1 depicts the significant differences found between infants with DS and those without DS in terms of the time elapsed until return to normal physiological conditions after puncture. However, this figure only includes the categories of baseline recovery time after crying, time to normalization of biological constants, and oxygen saturation levels. Statistically significant differences were found between healthy
babies and babies with DS in their baseline recovery time. It was found that the babies with DS took longer to recover after a puncture than control group. In this regard, different authors have suggested that patients with DS do not always show signs of pain or distress after a painful stimulus, when compared with the general population. Other authors agree that children with DS have limited ability to express their reaction to a painful stimulus by means of behavioral signs (Mafrica, Schifilliti, & Vincenzo, 2006). Hennequin et al. (2003) performed a pilot study to measure the capacity of people with DS to detect and express painful sensations in comparison with volunteers without DS. The results showed that individuals with DS were not insensitive to pain. However, they
270
Aguilar Cordero, Mur Villar, and Garcıa Garcıa
TABLE 2. Mean Values (and SD) and Significant Values for Down Syndrome and Gestational Age Factors at Birth Down Syndrome Term (n ¼ 15)
Preterm (n ¼ 5)
Healthy Term (n ¼ 14)
Preterm (n ¼ 6)
Baseline oxygen saturation 95.7% (2.7%) 96.6% (0.9%) 98.1% (1.6%) 98% (1.3%) Oxygen saturation after 89.7% (3.8%) 87.0% (6.2%) 96.4% (1.2%) 96.0% (0.6%) intervention Baseline heart rate 144.9 (7.0) 152.4 (4.6) 137.1 (5.9) 145.0 (5.9) Heart rate after intervention 165.2 (10.3) 174.2 (5.9) 158.1 (9.1) 163.0 (8.5) Maximum baseline blood 79.8 (4.4) 76 (1.6) 82.6 (7.3) 75.5 (3.7) pressure Maximum blood pressure after 87.1 (5.1) 84 (5.5) 89.9 (6.8) 87.0 (6.8) intervention Minimum baseline blood 52.5 (4.2) 51.2 (5.4) 52.9 (6.8) 44.8 (4) pressure Minimum blood pressure after 53.3 (5) 52.4 (4.3) 56.9 (6.4) 53 (5.1) intervention
ANOVA 2-Ways p Down Syndrome Gestational Factor Age Factor .011
