Journal of Obstetrics and Gynaecology, July 2014; 34: 400–402 © 2014 Informa UK, Ltd. ISSN 0144-3615 print/ISSN 1364-6893 online DOI: 10.3109/01443615.2014.897312
OBSTETRICS
Effect of oronasopharyngeal suction on arterial oxygen saturation in normal, term infants delivered vaginally: A prospective randomised controlled trial V. Modarres Nejad1, R. Hosseini1, A. Sarrafi Nejad2 & G. Shafiee3
J Obstet Gynaecol Downloaded from informahealthcare.com by Nyu Medical Center on 07/09/15 For personal use only.
1Department of Obstetrics and Gynaecology, Kerman University of Medical Sciences, Kerman-Iran, 2University of Medical Sciences, Kerman and 3Kerman University of Medical Sciences, Kerman, Iran
Oronasopharyngeal suction (ONPS) with a suction bulb at birth is a traditional practice in the initial management of healthy infants in Iran and many other countries. The purpose of this study was to compare the effects of oronasopharyngeal suction (ONPS) with those of no suction in normal, term newborns delivered vaginally. A total of 170 healthy term infants of first and single uncomplicated pregnancies, with clear amniotic fluid, vaginal delivery and cephalic presentation, enrolled in the trial during labour. Newborns were randomised into one of the two groups, according to the use of the ONPS procedure. Arterial oxygen saturation (SaO2) levels, heart rates, blood gases of umbilical cord and Apgar scores were determined. The mean SaO2 values over the first and fifth min of birth were similar in the two groups. The maximum time to reach SaO2 of ⱖ 92% was shorter in the no suction group. There were no statistically significant differences in the mean of heart rates, respiratory rates and Apgar scores between the groups. Apgar scores at 5 and 10 min were between 8 and 10 for all infants, respectively. Newborns receiving suction showed a statistically significant, lower mean partial carbon dioxide pressure (PCO2) and a significantly higher partial oxygen pressure (PO2) of umbilical artery. Although the differences were statistically significant, these were not considered clinically significant because values remained within normal ranges. According to this study, ONPS is not recommended as a routine procedure in normal, term infants delivered vaginally. Keywords: Neonate, oronasopharyngeal suction, oxygen saturation, vaginal delivery
Introduction Oronasopharyngeal suction (ONPS) with a suction bulb at birth is a traditional practice in the initial management of healthy infants (Cunningham et al. 2001). Mechanical compression of the thorax during passage through the birth channel is responsible for ejection of most of the pulmonary fluid through the oronasopharynx (Kalberg et al. 1962). ONPS helps pulmonary fluid expulsion, facilitates the entrance of air, especially in caesarean section (Ballard 1998; McCartney 2000). However, it is believed that pulmonary fluid starts to decrease towards the end of gestation (Dickson et al. 1986), during labour (Brown et al. 1983) and the first hours of postnatal life (Bland et al. 1982). Thus, the role of routine ONPS in elimination of lung liquid at birth in vigorous infants born at term is unknown. Previous stud-
ies have reported that the routine use of ONPS did not show any benefit in oxygenation of the newborn infants (Waltman et al. 2004; Gungor et al. 2006). It is possible that nasopharyngeal suction produces vagal-induced bradycardia and increased risk of infection (McCartney 2000). Pulse oximetry is a method that provides reliable continuous oxygen saturation values in newborns a few seconds after birth (Dimich et al. 1991; Brouillette and Waxman 1997). The Apgar score is a commonly used procedure for assessing immediate wellbeing at birth and diagnosis of fetal asphyxia (Gungor et al. 2005). The aim of this study was to evaluate the effectiveness of ONPS in term infants delivered vaginally, by measuring arterial oxygen saturation with the pulse oximeter and to determine Apgar scores in the first min after delivery, in the Iranian infants.
Material and methods The Ethics Committee at Afzalipoor Hospital, Kerman, Iran approved this study to assess the merits of ONPS in term infants delivered vaginally. Informed consent was obtained from mothers before enrolment. In the previous study by Gungor et al. (2006), the sample size was 140. Our study sample size was calculated based on the calculation performed by Gungor et al. (2006) and 15% was added to that value for drop out cases. By this method, the sample size was calculated to be 170. All infants were enrolled in the study. After exclusion of those with maternal or fetal pathological changes, medication before or during labour and evidence of fetal distress, 170 healthy term newborns of first and single pregnancies with clear amniotic fluid and vaginal delivery in the cephalic presentation, were selected for the study during labour. Newborns were randomised to either the ONPS group or the no suction group. In the suctioned group, this was performed immediately (⬍ 15 s) after birth by using a sterile polyethylene tube, and negative pressure did not surpass 30 cm H2O. In the no suction group, the intervention was only to remove any visible material. pH, partial carbon dioxide pressure (PCO2) and partial oxygen pressure (PO2) were determined in umbilical arterial samples. After aspiration, the newborns were separated into the two groups, were left under radiant heat and received standard care. A saturation sensor was attached to the middle finger of the right hand of the newborn, in order to monitor arterial oxygen
Correspondence: V. Modarres Nejad, Department of Obstetrics and Gynaecology, Kerman University of Medical Sciences, P.O. Box 13185-1678, Kerman, Iran. E-mail: [email protected]
Oronasopharyngeal suction and neonatal arterial oxygen saturation saturation (SaO2) and heart rate. Saturation measurements were evaluated only when the heart rate did not differ more than five beats from that obtained by the pulse oximeter. The first reading was determined at the first min of birth, until a SaO2 level of ⱖ 92% was reached. Apgar scores were reported at 1 and 5 min following delivery. All newborns were followed until the third day of life and when the results of the physical and neurological examination were normal, they were discharged from the hospital.
Statistical analysis
J Obstet Gynaecol Downloaded from informahealthcare.com by Nyu Medical Center on 07/09/15 For personal use only.
All data are presented as mean ⫾ SD, and frequency, where appropriate. Significant differences in general characteristics were determined by the χ2 and Student’s t-test. SPSS for Windows (version 16; SPSS Inc., Chicago, IL) was used for data analyses and p values of ⬍ 0.05 were considered statistically significant.
Results A total of 170 neonates completed the study (n ⫽ 85 per group). All newborns were in good clinical condition and did not need any supplement oxygen. There was no significant difference in characteristics, including gestational age, birth weight, sex, heart rate and respiratory rate in the two groups (Table I). Although the values of all newborns in both groups were in the normal range, the mean PO2 of the the umbilical artery was lower in the no suction group, while the mean PCO2 of umbilical artery was higher (p ⬍ 0.05). No difference was found in the pH in the two groups. The primary end-point of the study was the time to reach 92% SaO2. While the slowest newborn in the no suction group achieved an SaO2 of 92% at 9 min of life, it took 11 min for the slowest one in the suction group (p ⫽ 0.002) (Table II). None of the neonates in ONPS group achieved 92% before 8 min of life. The number of infants in at 10 min who had yet to reach that threshold, was eight in the suction and no suction group. The secondary outcome variable was the Apgar scores. Apgar scores of all newborns were 8 or 9 at 1 min of life. The mean was 8.96 ⫾ 0.19 in ONPS group and 8.99 ⫾ 0.11 in the no suction group during the first min of life (p ⫽ 0.3). All neonates had a score of 10 at 5 min. Table I. Maternal and fetal characteristics of suctioned and no suctioned groups. Characteristics Maternal age (years) Fetal Gestational age (weeks) Birth weight (g) Sex (F/M)∗ Heart rate Respiratory rate Umbilical artery pH PO2 PCO2 Umbilical vein pH PO2 PCO2
No suction group (n ⫽ 85)
Suction group (n ⫽ 85)
p value
25.33 ⫾ 5.04
23.84 ⫾ 4.78
0.05
38.73 ⫾ 1.05 38.72 ⫾ 1.16 3087.06 ⫾ 285.69 3126.47 ⫾ 283.95 46/39 39/46 146.67 ⫾ 9.74 146.29 ⫾ 8.73 62.86 ⫾ 3.49 61.94 ⫾ 3.47
Data are mean ⫾ SD; ∗Frequency.
0.9 0.4 0.3 0.8 0.09
7.22 ⫾ 0.04 22.54 ⫾ 3.14 46.29 ⫾ 4.98
7.20 ⫾ 0.43 23.77 ⫾ 3.85 43.5 ⫾ 8.87
0.6 0.02 0.01
7.27 ⫾ 0.04 27.38 ⫾ 3.14 37.91 ⫾ 4.46
7.25 ⫾ 0.43 26.36 ⫾ 5.2 38.43 ⫾ 7.16
0.7 0.1 0.6
401
Table II. Comparison of newborn SaO2 values of suctioned and no suctioned groups. SaO2 values Minutes after birth 1 3 5 9 10 11
No suction group (n ⫽ 85)
Suction group (n ⫽ 85)
p value
75.46 ⫾ 7.51 78.58 ⫾ 8.18 85.51 ⫾ 6.64 92.00 ⫾ 5.19 – –
75.91 ⫾ 6.95 79.58 ⫾ 7.98 85.02 ⫾ 4.85 89.23 ⫾ 5.17 90.86 ⫾ 3.81 92.04 ⫾ 3.86
0.7 0.4 0.6 0.002 NA NA
Data have been shown as mean ⫾ SD. NA, not applicable; SaO2, arterial oxygen saturation.
Discussion The purpose of this prospective, randomised controlled trial was to compare the effects of oronasopharyngeal suction (ONPS) with those of no suction in normal, term and vaginally born infants. We found that no suctioning was superior to ONPS in reaching SaO2 levels of ⱖ 92%. Other outcomes including Apgar scores at 1 and 5 min and heart rate were similar. Pulse oximetry is a simple and non-invasive method that can be widely used in the immediate evaluation changes in the neonate’s SaO2 at birth (Dimich et al. 1991; Harris et al. 1986). We found that the neonates remain relatively oxygen desaturated after birth, regardless of suctioning, but the SaO2 increases toward normal values during the initial minute of life, which is consistent with Dimich et al.’s 1991 findings. Several studies have reported a functionally open ductus arteriosus and right-to-left shunting in the early period after birth (Oliver et al. 1961; Linde and Wegelius 1954). Prolonged shunting could be important for the delay in reaching a high SaO2 level in all infants. It has been shown in premature infants and in neonates with persistent pulmonary hypertension or hypoxia (Fishma 1964; Carrasco et al. 1997). In our study, despite the significant difference in achievement in an SaO2 level of 92% between the groups without suction and ONPS, none of the infants had respiratory distress. In support of our findings, other studies showed that the routine use of oronasopharyngeal suction immediately after birth did not show a benefit in oxygenation of the neonates (Waltman et al. 2004, Carrasco et al. 1997; Estol 1992). Gungor et al. (2005), in a prospective randomised controlled trial, compared the effects of oronasopharyngeal suction with those of no suction in normal, term and vaginally born newborns. The no suction group showed higher SaO2 values through the first 6 min of life. The suction group took longer to reach SaO2 of ⱖ 92% (11 vs 6 min). In addition, in a pilot study, investigators have shown that the suction group had lower SaO2 levels and took longer to reach 92% SaO2. They found that the suction group had slightly lower, although non-significant, SaO2 at 5 min of age. However, by 15 min of life, this trend reversed, and the newborn’s group with bulb suctioning had a higher level of SaO2. (Waltman et al. 2004) In contrast to their results, we found that the suctioned group had higher SaO2 values through the first 3 min of life although non-significant. However, by 5 min, this group had a lower level of SaO2. Furthermore, in a study with neonates delivered by caesarean section (Gungor et al. 2006), investigators found that birth method did not affect oxygen saturations immediately after birth and similar results have been in the current study; the suction
J Obstet Gynaecol Downloaded from informahealthcare.com by Nyu Medical Center on 07/09/15 For personal use only.
402
V. Modarres Nejad et al.
group had lower levels of SaO2 and took longer to reach SaO2 levels of 92%. Another study demonstrated that the average value for SaO2 was significantly lower in the suctioned group between the 1 and 6 min of life and there were similar results in the current study; the time to reach 92% saturation was shorter in the no suction group (Carrasco et al. 1997). The Apgar score is a common method of evaluation of neonatal wellbeing at birth. Several studies demonstrated that Apgar scores are potentially misleading as predictors of the grade of oxygenation and its diagnostic value as a means of identifying birth asphyxia has been challenged (Sendak et al. 1989; Marrin and Paes 1988). Our results confirm previous studies (Gungor et al. 2006; Gungor et al. 2005) which did not observe any significant difference in Apgar scores with respect to the suctioning procedure. Routine umbilical cord blood gas has been recommended as a more objective measure of the condition of the newborn. This practice is important because umbilical cord blood gas analysis may assist with clinical management (Thorp and Rushing 1999; Duerbeck et al. 1992). Our findings are in-line with earlier reports (Gungor et al. 2006; Carrasco et al. 1997)] and showed the mean PO2 value was lower in the no suction group, while the mean PCO2 value was higher. Since the values of all newborns in both groups are in the normal range, the clinical importance between suction and no suction groups is not clear. Although, ONPS is used in clinical situations, such as the presence of meconium, Vain et al. (2004) in a randomised controlled trial, showed routine intrapartum ONPS in term neonates born through meconium-stained amniotic fluid, did not prevent from Meconium Aspiration Syndrome. Evidence from previous studies shows that rapid removal of fluid from airspaces establishes the timely transition from placental to lung respiration (Barker and Olver 2002; Bland 2001). It might therefore be expected that ONPS would have a positive effect on oxygen delivery, although, there has been no research supporting this. To the best of our knowledge, this is the first study in Iran, conducted to determine whether oronasopharyngeal suction has positive impact in reaching ⱖ 92% oxygen saturation in term, healthy neonates delivered vaginally. In conclusion, our findings showed that no suctioning was superior to routine suctioning in reaching ⱖ 92% SaO2 in newborns. No significant difference was observed in Apgar scores at 5 and 10 min, heart rates and respiratory rates in the groups. Thus, ONPS in term, normal neonates delivered vaginally, is not beneficial and has negative effects on levels of SaO2.
Acknowledgement The authors would like to thank Farzan Institute for Research and Technology for technical assistance. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
References Ballard R. 1998. Resuscitation in the delivery room. In: Ballard R, editor. Avery’s diseases of the newborn. 7th ed. Philadelphia: Saunders. p 319–333. Barker PM, Olver RE. 2002. Invited review: clearance lung liquid during perinatal period. Journal of Applied Physiology 93:1542–1548. Bland RD, Hansen TN, Haberken CM, Bressack MA, Hazinski T A, Raj JU et al. 1982. Lung fluid balance in lambs before and after birth. Journal of Applied Physiology 53:992–1004. Bland RD. 2001. Loss of liquid from the lung lumen in labor: more than a simple ‘squeeze’. American Journal of Physiology. Lung Cellular and Molecular Physiology 280:602–605. Brouillette RT, Waxman DH. 1997. Evaluation of the newborn’s blood gas status. Clinical Chemistry 43:215–221. Brown MJ, Olver RE, Ramsden CA, Strang LB, Walters DU. 1983. Effects of adrenaline and of spontaneous labour on the secretion and absorption of lung liquid in the fetal lamb. Journal of Physiology 344:137–152. Carrasco M, Martell M, Estol PC. 1997. Oronasopharyngeal suction at birth: effects on arterial oxygen saturation. Journal of Pediatrics 130:832–834. Cunningham FE, Gant NF, Leveno KJ, Gilstrap LC, Hauth JC, Wenstrom KD. 2001. In: Williams’ obstetrics. The Newborn Infant. 21st ed. New York: McGraw-Hill. p. 385–402. Dickson KA, Maloney JE, Berger PJ. 1986. Decline in lung liquid volume before labor in fetal lambs. Journal of Applied Physiology 61:2266–2272. Dimich I, Singh PP, Adell A, Hendler M, Sonnenklar N, Jhaveri M. 1991. Evaluation of oxygen saturation monitoring by pulse oximetry in neonates in the delivery system. Canadian Journal of Anesthesia 38:985–988. Duerbeck NB, Chaffin DG, Seeds JW. 1992. A practical approach to umbilical artery pH and blood gas determinations. Obstetrics and Gynecology 79:959–962. Estol P, Piriz H, Basalo S, Simini F, Grela C. 1992. Oro-naso-pharyngeal suction at birth: Effects on respiratory adaptation of normal term vaginally born infants. Journal of Perinatal Medicine 20:297–305. Fishma AP. 1964. Respiratory gases in the regulation of the pulmonary circulation. Physiological Reviews 41:214–219. Gungor S, Kurt E, Teksoz E, Goktolga U, Ceyhan T, Baser I. 2006. Oronasopharyngeal suction versus no suction in normal and term infants delivered by elective cesarean section: A prospective randomized controlled trial. Gynecologic and Obstetric Investigation 61:9–14. Gungor S, Teksoz E, Ceyhan T, Kurt E, Goktolga U, Baser I . 2005. Oronasopharyngeal suction versus no suction in normal, term and vaginally born Infants: A prospective randomized controlled trial. Australian and New Zealand Journal of Obstetrics and Gynecology 45:453–456. Harris A, Sandak M, Donhaus R. 1986. Changes in arterial oxygen saturation immediately after birth in the human neonates. Journal of Pediatrics 109:177–179. Kalberg P, Adams FH, Geubellae F, Wallgren G. 1962. Alteration of the infant’s thorax during vaginal delivery. Acta Obstetricia et Gynecologica Scandinavica 41:223–229. Linde J, Wegelius R. 1954. Human fetal circulation changes in the cardiovascular system at birth and disturbances in the post-natal closure of the foramen ovale and ductus arteriosus. Cold Spring Harbor Symposia on Quantitative Biology 19:109–125. Marrin M, Paes B. 1988. Birth asphyxia: does the Apgar score have diagnostic value? Obstetrics and Gynecology 72:120–123. McCartney P. 2000. Bulb syringes in newborn care. American Journal of Maternal/Child Nursing 25:217. Oliver Tk, Demis JA, Bates GD. 1961. Serial blood gas tension and acid base balance during the first hour of life in human infants. Acta Paediatrica Scandinavica 50:346–360. Sendak M, Harris AP, Donham RT. 1989. The sensitivity of Apgar scores as an indicator of hypoxia. Anesthesiology 71:A899. Thorp JA, Rushing RS. 1999. Umbilical cord blood gas analysis. Obstetrics and Gynecology Clinics of North America 26:695–709. Vain NE, Szyld EG, Prudent LM, Wiswell TE, Aguilar AM, Vivas NI. 2004. Oropharyngeal and nasopharyngeal suctioning of meconium- stained neonates before delivery of their shoulders: multicentre randomised controlled trial. Lancet 364:597–602. Waltman PA, Brewer JM, Rogers BP, May WL. 2004. Building evidence for practice: A pilot study of newborn bulb suctioning at birth. Journal of Midwifery and Women’s Health 49:32–38.
OBSTETRICS
Effect of oronasopharyngeal suction on arterial oxygen saturation in normal, term infants delivered vaginally: A prospective randomised controlled trial V. Modarres Nejad1, R. Hosseini1, A. Sarrafi Nejad2 & G. Shafiee3
J Obstet Gynaecol Downloaded from informahealthcare.com by Nyu Medical Center on 07/09/15 For personal use only.
1Department of Obstetrics and Gynaecology, Kerman University of Medical Sciences, Kerman-Iran, 2University of Medical Sciences, Kerman and 3Kerman University of Medical Sciences, Kerman, Iran
Oronasopharyngeal suction (ONPS) with a suction bulb at birth is a traditional practice in the initial management of healthy infants in Iran and many other countries. The purpose of this study was to compare the effects of oronasopharyngeal suction (ONPS) with those of no suction in normal, term newborns delivered vaginally. A total of 170 healthy term infants of first and single uncomplicated pregnancies, with clear amniotic fluid, vaginal delivery and cephalic presentation, enrolled in the trial during labour. Newborns were randomised into one of the two groups, according to the use of the ONPS procedure. Arterial oxygen saturation (SaO2) levels, heart rates, blood gases of umbilical cord and Apgar scores were determined. The mean SaO2 values over the first and fifth min of birth were similar in the two groups. The maximum time to reach SaO2 of ⱖ 92% was shorter in the no suction group. There were no statistically significant differences in the mean of heart rates, respiratory rates and Apgar scores between the groups. Apgar scores at 5 and 10 min were between 8 and 10 for all infants, respectively. Newborns receiving suction showed a statistically significant, lower mean partial carbon dioxide pressure (PCO2) and a significantly higher partial oxygen pressure (PO2) of umbilical artery. Although the differences were statistically significant, these were not considered clinically significant because values remained within normal ranges. According to this study, ONPS is not recommended as a routine procedure in normal, term infants delivered vaginally. Keywords: Neonate, oronasopharyngeal suction, oxygen saturation, vaginal delivery
Introduction Oronasopharyngeal suction (ONPS) with a suction bulb at birth is a traditional practice in the initial management of healthy infants (Cunningham et al. 2001). Mechanical compression of the thorax during passage through the birth channel is responsible for ejection of most of the pulmonary fluid through the oronasopharynx (Kalberg et al. 1962). ONPS helps pulmonary fluid expulsion, facilitates the entrance of air, especially in caesarean section (Ballard 1998; McCartney 2000). However, it is believed that pulmonary fluid starts to decrease towards the end of gestation (Dickson et al. 1986), during labour (Brown et al. 1983) and the first hours of postnatal life (Bland et al. 1982). Thus, the role of routine ONPS in elimination of lung liquid at birth in vigorous infants born at term is unknown. Previous stud-
ies have reported that the routine use of ONPS did not show any benefit in oxygenation of the newborn infants (Waltman et al. 2004; Gungor et al. 2006). It is possible that nasopharyngeal suction produces vagal-induced bradycardia and increased risk of infection (McCartney 2000). Pulse oximetry is a method that provides reliable continuous oxygen saturation values in newborns a few seconds after birth (Dimich et al. 1991; Brouillette and Waxman 1997). The Apgar score is a commonly used procedure for assessing immediate wellbeing at birth and diagnosis of fetal asphyxia (Gungor et al. 2005). The aim of this study was to evaluate the effectiveness of ONPS in term infants delivered vaginally, by measuring arterial oxygen saturation with the pulse oximeter and to determine Apgar scores in the first min after delivery, in the Iranian infants.
Material and methods The Ethics Committee at Afzalipoor Hospital, Kerman, Iran approved this study to assess the merits of ONPS in term infants delivered vaginally. Informed consent was obtained from mothers before enrolment. In the previous study by Gungor et al. (2006), the sample size was 140. Our study sample size was calculated based on the calculation performed by Gungor et al. (2006) and 15% was added to that value for drop out cases. By this method, the sample size was calculated to be 170. All infants were enrolled in the study. After exclusion of those with maternal or fetal pathological changes, medication before or during labour and evidence of fetal distress, 170 healthy term newborns of first and single pregnancies with clear amniotic fluid and vaginal delivery in the cephalic presentation, were selected for the study during labour. Newborns were randomised to either the ONPS group or the no suction group. In the suctioned group, this was performed immediately (⬍ 15 s) after birth by using a sterile polyethylene tube, and negative pressure did not surpass 30 cm H2O. In the no suction group, the intervention was only to remove any visible material. pH, partial carbon dioxide pressure (PCO2) and partial oxygen pressure (PO2) were determined in umbilical arterial samples. After aspiration, the newborns were separated into the two groups, were left under radiant heat and received standard care. A saturation sensor was attached to the middle finger of the right hand of the newborn, in order to monitor arterial oxygen
Correspondence: V. Modarres Nejad, Department of Obstetrics and Gynaecology, Kerman University of Medical Sciences, P.O. Box 13185-1678, Kerman, Iran. E-mail: [email protected]
Oronasopharyngeal suction and neonatal arterial oxygen saturation saturation (SaO2) and heart rate. Saturation measurements were evaluated only when the heart rate did not differ more than five beats from that obtained by the pulse oximeter. The first reading was determined at the first min of birth, until a SaO2 level of ⱖ 92% was reached. Apgar scores were reported at 1 and 5 min following delivery. All newborns were followed until the third day of life and when the results of the physical and neurological examination were normal, they were discharged from the hospital.
Statistical analysis
J Obstet Gynaecol Downloaded from informahealthcare.com by Nyu Medical Center on 07/09/15 For personal use only.
All data are presented as mean ⫾ SD, and frequency, where appropriate. Significant differences in general characteristics were determined by the χ2 and Student’s t-test. SPSS for Windows (version 16; SPSS Inc., Chicago, IL) was used for data analyses and p values of ⬍ 0.05 were considered statistically significant.
Results A total of 170 neonates completed the study (n ⫽ 85 per group). All newborns were in good clinical condition and did not need any supplement oxygen. There was no significant difference in characteristics, including gestational age, birth weight, sex, heart rate and respiratory rate in the two groups (Table I). Although the values of all newborns in both groups were in the normal range, the mean PO2 of the the umbilical artery was lower in the no suction group, while the mean PCO2 of umbilical artery was higher (p ⬍ 0.05). No difference was found in the pH in the two groups. The primary end-point of the study was the time to reach 92% SaO2. While the slowest newborn in the no suction group achieved an SaO2 of 92% at 9 min of life, it took 11 min for the slowest one in the suction group (p ⫽ 0.002) (Table II). None of the neonates in ONPS group achieved 92% before 8 min of life. The number of infants in at 10 min who had yet to reach that threshold, was eight in the suction and no suction group. The secondary outcome variable was the Apgar scores. Apgar scores of all newborns were 8 or 9 at 1 min of life. The mean was 8.96 ⫾ 0.19 in ONPS group and 8.99 ⫾ 0.11 in the no suction group during the first min of life (p ⫽ 0.3). All neonates had a score of 10 at 5 min. Table I. Maternal and fetal characteristics of suctioned and no suctioned groups. Characteristics Maternal age (years) Fetal Gestational age (weeks) Birth weight (g) Sex (F/M)∗ Heart rate Respiratory rate Umbilical artery pH PO2 PCO2 Umbilical vein pH PO2 PCO2
No suction group (n ⫽ 85)
Suction group (n ⫽ 85)
p value
25.33 ⫾ 5.04
23.84 ⫾ 4.78
0.05
38.73 ⫾ 1.05 38.72 ⫾ 1.16 3087.06 ⫾ 285.69 3126.47 ⫾ 283.95 46/39 39/46 146.67 ⫾ 9.74 146.29 ⫾ 8.73 62.86 ⫾ 3.49 61.94 ⫾ 3.47
Data are mean ⫾ SD; ∗Frequency.
0.9 0.4 0.3 0.8 0.09
7.22 ⫾ 0.04 22.54 ⫾ 3.14 46.29 ⫾ 4.98
7.20 ⫾ 0.43 23.77 ⫾ 3.85 43.5 ⫾ 8.87
0.6 0.02 0.01
7.27 ⫾ 0.04 27.38 ⫾ 3.14 37.91 ⫾ 4.46
7.25 ⫾ 0.43 26.36 ⫾ 5.2 38.43 ⫾ 7.16
0.7 0.1 0.6
401
Table II. Comparison of newborn SaO2 values of suctioned and no suctioned groups. SaO2 values Minutes after birth 1 3 5 9 10 11
No suction group (n ⫽ 85)
Suction group (n ⫽ 85)
p value
75.46 ⫾ 7.51 78.58 ⫾ 8.18 85.51 ⫾ 6.64 92.00 ⫾ 5.19 – –
75.91 ⫾ 6.95 79.58 ⫾ 7.98 85.02 ⫾ 4.85 89.23 ⫾ 5.17 90.86 ⫾ 3.81 92.04 ⫾ 3.86
0.7 0.4 0.6 0.002 NA NA
Data have been shown as mean ⫾ SD. NA, not applicable; SaO2, arterial oxygen saturation.
Discussion The purpose of this prospective, randomised controlled trial was to compare the effects of oronasopharyngeal suction (ONPS) with those of no suction in normal, term and vaginally born infants. We found that no suctioning was superior to ONPS in reaching SaO2 levels of ⱖ 92%. Other outcomes including Apgar scores at 1 and 5 min and heart rate were similar. Pulse oximetry is a simple and non-invasive method that can be widely used in the immediate evaluation changes in the neonate’s SaO2 at birth (Dimich et al. 1991; Harris et al. 1986). We found that the neonates remain relatively oxygen desaturated after birth, regardless of suctioning, but the SaO2 increases toward normal values during the initial minute of life, which is consistent with Dimich et al.’s 1991 findings. Several studies have reported a functionally open ductus arteriosus and right-to-left shunting in the early period after birth (Oliver et al. 1961; Linde and Wegelius 1954). Prolonged shunting could be important for the delay in reaching a high SaO2 level in all infants. It has been shown in premature infants and in neonates with persistent pulmonary hypertension or hypoxia (Fishma 1964; Carrasco et al. 1997). In our study, despite the significant difference in achievement in an SaO2 level of 92% between the groups without suction and ONPS, none of the infants had respiratory distress. In support of our findings, other studies showed that the routine use of oronasopharyngeal suction immediately after birth did not show a benefit in oxygenation of the neonates (Waltman et al. 2004, Carrasco et al. 1997; Estol 1992). Gungor et al. (2005), in a prospective randomised controlled trial, compared the effects of oronasopharyngeal suction with those of no suction in normal, term and vaginally born newborns. The no suction group showed higher SaO2 values through the first 6 min of life. The suction group took longer to reach SaO2 of ⱖ 92% (11 vs 6 min). In addition, in a pilot study, investigators have shown that the suction group had lower SaO2 levels and took longer to reach 92% SaO2. They found that the suction group had slightly lower, although non-significant, SaO2 at 5 min of age. However, by 15 min of life, this trend reversed, and the newborn’s group with bulb suctioning had a higher level of SaO2. (Waltman et al. 2004) In contrast to their results, we found that the suctioned group had higher SaO2 values through the first 3 min of life although non-significant. However, by 5 min, this group had a lower level of SaO2. Furthermore, in a study with neonates delivered by caesarean section (Gungor et al. 2006), investigators found that birth method did not affect oxygen saturations immediately after birth and similar results have been in the current study; the suction
J Obstet Gynaecol Downloaded from informahealthcare.com by Nyu Medical Center on 07/09/15 For personal use only.
402
V. Modarres Nejad et al.
group had lower levels of SaO2 and took longer to reach SaO2 levels of 92%. Another study demonstrated that the average value for SaO2 was significantly lower in the suctioned group between the 1 and 6 min of life and there were similar results in the current study; the time to reach 92% saturation was shorter in the no suction group (Carrasco et al. 1997). The Apgar score is a common method of evaluation of neonatal wellbeing at birth. Several studies demonstrated that Apgar scores are potentially misleading as predictors of the grade of oxygenation and its diagnostic value as a means of identifying birth asphyxia has been challenged (Sendak et al. 1989; Marrin and Paes 1988). Our results confirm previous studies (Gungor et al. 2006; Gungor et al. 2005) which did not observe any significant difference in Apgar scores with respect to the suctioning procedure. Routine umbilical cord blood gas has been recommended as a more objective measure of the condition of the newborn. This practice is important because umbilical cord blood gas analysis may assist with clinical management (Thorp and Rushing 1999; Duerbeck et al. 1992). Our findings are in-line with earlier reports (Gungor et al. 2006; Carrasco et al. 1997)] and showed the mean PO2 value was lower in the no suction group, while the mean PCO2 value was higher. Since the values of all newborns in both groups are in the normal range, the clinical importance between suction and no suction groups is not clear. Although, ONPS is used in clinical situations, such as the presence of meconium, Vain et al. (2004) in a randomised controlled trial, showed routine intrapartum ONPS in term neonates born through meconium-stained amniotic fluid, did not prevent from Meconium Aspiration Syndrome. Evidence from previous studies shows that rapid removal of fluid from airspaces establishes the timely transition from placental to lung respiration (Barker and Olver 2002; Bland 2001). It might therefore be expected that ONPS would have a positive effect on oxygen delivery, although, there has been no research supporting this. To the best of our knowledge, this is the first study in Iran, conducted to determine whether oronasopharyngeal suction has positive impact in reaching ⱖ 92% oxygen saturation in term, healthy neonates delivered vaginally. In conclusion, our findings showed that no suctioning was superior to routine suctioning in reaching ⱖ 92% SaO2 in newborns. No significant difference was observed in Apgar scores at 5 and 10 min, heart rates and respiratory rates in the groups. Thus, ONPS in term, normal neonates delivered vaginally, is not beneficial and has negative effects on levels of SaO2.
Acknowledgement The authors would like to thank Farzan Institute for Research and Technology for technical assistance. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
References Ballard R. 1998. Resuscitation in the delivery room. In: Ballard R, editor. Avery’s diseases of the newborn. 7th ed. Philadelphia: Saunders. p 319–333. Barker PM, Olver RE. 2002. Invited review: clearance lung liquid during perinatal period. Journal of Applied Physiology 93:1542–1548. Bland RD, Hansen TN, Haberken CM, Bressack MA, Hazinski T A, Raj JU et al. 1982. Lung fluid balance in lambs before and after birth. Journal of Applied Physiology 53:992–1004. Bland RD. 2001. Loss of liquid from the lung lumen in labor: more than a simple ‘squeeze’. American Journal of Physiology. Lung Cellular and Molecular Physiology 280:602–605. Brouillette RT, Waxman DH. 1997. Evaluation of the newborn’s blood gas status. Clinical Chemistry 43:215–221. Brown MJ, Olver RE, Ramsden CA, Strang LB, Walters DU. 1983. Effects of adrenaline and of spontaneous labour on the secretion and absorption of lung liquid in the fetal lamb. Journal of Physiology 344:137–152. Carrasco M, Martell M, Estol PC. 1997. Oronasopharyngeal suction at birth: effects on arterial oxygen saturation. Journal of Pediatrics 130:832–834. Cunningham FE, Gant NF, Leveno KJ, Gilstrap LC, Hauth JC, Wenstrom KD. 2001. In: Williams’ obstetrics. The Newborn Infant. 21st ed. New York: McGraw-Hill. p. 385–402. Dickson KA, Maloney JE, Berger PJ. 1986. Decline in lung liquid volume before labor in fetal lambs. Journal of Applied Physiology 61:2266–2272. Dimich I, Singh PP, Adell A, Hendler M, Sonnenklar N, Jhaveri M. 1991. Evaluation of oxygen saturation monitoring by pulse oximetry in neonates in the delivery system. Canadian Journal of Anesthesia 38:985–988. Duerbeck NB, Chaffin DG, Seeds JW. 1992. A practical approach to umbilical artery pH and blood gas determinations. Obstetrics and Gynecology 79:959–962. Estol P, Piriz H, Basalo S, Simini F, Grela C. 1992. Oro-naso-pharyngeal suction at birth: Effects on respiratory adaptation of normal term vaginally born infants. Journal of Perinatal Medicine 20:297–305. Fishma AP. 1964. Respiratory gases in the regulation of the pulmonary circulation. Physiological Reviews 41:214–219. Gungor S, Kurt E, Teksoz E, Goktolga U, Ceyhan T, Baser I. 2006. Oronasopharyngeal suction versus no suction in normal and term infants delivered by elective cesarean section: A prospective randomized controlled trial. Gynecologic and Obstetric Investigation 61:9–14. Gungor S, Teksoz E, Ceyhan T, Kurt E, Goktolga U, Baser I . 2005. Oronasopharyngeal suction versus no suction in normal, term and vaginally born Infants: A prospective randomized controlled trial. Australian and New Zealand Journal of Obstetrics and Gynecology 45:453–456. Harris A, Sandak M, Donhaus R. 1986. Changes in arterial oxygen saturation immediately after birth in the human neonates. Journal of Pediatrics 109:177–179. Kalberg P, Adams FH, Geubellae F, Wallgren G. 1962. Alteration of the infant’s thorax during vaginal delivery. Acta Obstetricia et Gynecologica Scandinavica 41:223–229. Linde J, Wegelius R. 1954. Human fetal circulation changes in the cardiovascular system at birth and disturbances in the post-natal closure of the foramen ovale and ductus arteriosus. Cold Spring Harbor Symposia on Quantitative Biology 19:109–125. Marrin M, Paes B. 1988. Birth asphyxia: does the Apgar score have diagnostic value? Obstetrics and Gynecology 72:120–123. McCartney P. 2000. Bulb syringes in newborn care. American Journal of Maternal/Child Nursing 25:217. Oliver Tk, Demis JA, Bates GD. 1961. Serial blood gas tension and acid base balance during the first hour of life in human infants. Acta Paediatrica Scandinavica 50:346–360. Sendak M, Harris AP, Donham RT. 1989. The sensitivity of Apgar scores as an indicator of hypoxia. Anesthesiology 71:A899. Thorp JA, Rushing RS. 1999. Umbilical cord blood gas analysis. Obstetrics and Gynecology Clinics of North America 26:695–709. Vain NE, Szyld EG, Prudent LM, Wiswell TE, Aguilar AM, Vivas NI. 2004. Oropharyngeal and nasopharyngeal suctioning of meconium- stained neonates before delivery of their shoulders: multicentre randomised controlled trial. Lancet 364:597–602. Waltman PA, Brewer JM, Rogers BP, May WL. 2004. Building evidence for practice: A pilot study of newborn bulb suctioning at birth. Journal of Midwifery and Women’s Health 49:32–38.
