Key findings:

The study compared left lateral and right lateral positioning effects on gastric emptying and physiological parameters in preterm neonates. Gastric residual volume was significantly lower in the right lateral position, suggesting faster gastric emptying. However, physiological parameters remained unaffected by positioning. The study recommends adopting right lateral positioning post-feeding for improved gastric emptying in neonates.

What is known and what is new?

The abstract discusses a study comparing the effects of left lateral positioning versus right lateral positioning on gastric emptying and physiological parameters among preterm neonates. Known is the ongoing debate regarding the influence of body position on neonatal health. Novel is the finding that right lateral positioning facilitates faster gastric emptying without affecting physiological parameters.

What is the implication, and what should change now?

The study highlights the importance of body positioning in preterm neonates, specifically demonstrating that right lateral positioning post-feeding enhances gastric emptying without affecting physiological parameters. This suggests a practical implication for nursing practice, advocating for the adoption of right lateral positioning to promote better gastric emptying in neonates. The abstract could benefit from clearer delineation of the study's limitations and future research directions for enhanced clarity.

Newborn babies contribute to the foundation of a nation. A country enhances the quality of human resources with healthy and sturdy babies because they are likely to become physically and mentally strong adults in future [1].

It is expected that, after conception the baby will be born after 37 weeks of complete gestational age and with birth weight more than 2.5 k.g. But, often the birth does not occur according to expectation, and results in preterm and low birth weight neonate. 

Preterm neonates often face multiple complications; including respiratory, gastro-intestinal, neurological and nutritional problems, due to preterm delivery [2].
 

Neonatal period is the most crucial period of a child’s life. At this transitional stage, the most profound physiological changes occur in all the systems for adjustment to extrauterine life. The immature body system of the preterm infants continues to be challenging and ever changing. Preterm neonates often need long term care to overcome growth insufficiency. The neonates born before 34 weeks usually are unable to breastfeed. To accelerate weight gain and prevention of complications due to immaturity is the main purpose of care for the preterm neonates. But feeding of the immature neonates is often associated with many problems. One of the most concerning problems in feeding of neonate is the presence of pre-feed gastric residue, beyond accepted range, which indicates delayed gastric emptying and may be an early sign of intolerance of feed.

The overall neonatal mortality has decreased in the whole world from 4.4 million in 1990 to 1.3 million in 2010. But still the complications of early birth is considered as the main cause of 1 million deaths of neonates. Although the survival rate of premature and very low birth weight neonates have increased markedly with the advancement of medical  technology, till now it is a challenge for the nurses and doctors in newborn care unit to maintain their physiological parameters within optimum range, along with establishment and progression of enteral feeding, which depends on gastric emptying. Beside the high technological care there are some simple measures done by the nurses in the newborn care units to fasten gastric emptying, and maintaining the heart rate, respiratory rate and oxygen saturation within normal range, is the proper positioning of the neonate. 

There are advantages and disadvantages for each particular body position, the neonate may be placed. Among the most beneficial positions for neonates, prone position is associated with improvement of oxygenation, ventilation, and improved lung compliance. Gastro-oesophageal reflux is also reduced in this position and gastric emptying is being optimized. There is decreased energy expenditure and improved sleep state, improved thermoregulation, lower levels of apnoea of prematurity associated with this position. For the neonate nurse in prone position is emphasised in several studies as this position is associated with so many benefits, but, one major risk is also associated with this position which may be related to loss of life of a neonate [3] suggested to avoid prone sleeping of the neonate and adopt any non prone sleeping position as prone position is associated with Sudden Infant death Syndrome (SIDS). Skill is required in placing the neonate in a prone position. Along with this, close observation and monitoring is required while the neonate is in a prone position. On the other hand, the supine position is most commonly practiced by the nurses in neonatal care units for the benefit of easy observation and handling of neonates, but, this position is associated with some disadvantages like, increased energy expenditure, less effective lung ventilation, higher oxygen requirements, delayed gastric emptying, having least control over their body movement and have to fight gravity for all movement, and if body is not supported correctly head flattening, flay out of limbs along with poor muscle tone. Whereas, lateral position is associated with more benefits, most importantly gastric emptying is increased, as the stomach empties to the right and aided by gravity in this position, gastric reflux is also reduced because gravity will mean the stomach contents have to flow upward, making reflux more difficult. Disadvantages of lateral are few like lower arm and legs could feel ‘squashed’ and/or receive injuries pressure injuries may occur if left in the same position for a prolonged time [4]. Less serious and less frequent disadvantages are associated with lateral positions compared to prone and supine position. So, keeping in mind all the findings related to adverse effects of prone and supine positioning, left lateral and right lateral positioning can be used by the nurses as an alternative position. There is very limited study regarding the effects of left lateral and right lateral positioning of the neonate.

Thus, in the study conducted by Eghbalian F, Moeinipour A [5]., in 2008, emphasized that the optimal oxygenation is very important in preterm infants. And it is important to maintain proper oxygen range according to the gestational age and age of the infants. There are various methods, including positioning, for improving and maintaining the optimal oxygenation and heart rate within desirable range. So, Selection of the proper positioning for the neonate is very important. 

Hwang SK [6]., in 2003, measured gastric residuals in five different positions at 30, 60, 90, 120, 150, 180 minutes after feeding. At 180 minutes after feeding the gastric residual volume was lower (0.35±0.73) in the right lateral than in the left lateral (3.01±4.02). The positions had highly significant differences in gastric residuals (p<0.001). The study concluded that placement in the right lateral position after feeding could reduce gastric residuals, and thus, increase gastric emptying.

Kim JM, Lee LR, Seok MD, Oh YK. [7] in the Korean journal Perinatol, 2009, emphasized the effects of various body positions among neonates and about the controversies regarding best position. It is mentioned in this study that, Left lateral, right lateral, supine and prone positions used in the clinical settings on change of gastric residuals over time have not been fully addressed in infants. Even the studies conducted on LBWs, the findings of the studies did not lead to clinical applications. Therefore, controversies regarding the best positioning after feeding remain till now.

During clinical field posting at Newborn Care Unit for more than six years, the investigator identified that there are numbers of neonates suffering from delayed gastric emptying. There is also a debate among the doctors and nurses regarding the positioning of the neonate after feeding. On the basis of discussion with the paediatric doctors and paediatric nurses, the investigator was interested in the topic. Being a primary caregiver to the neonates in newborn care units following questions aroused in her mind:

• When do the neonates undergo delayed gastric emptying?
• Does positioning of the baby affect gastric emptying?
• Is there any difference between gastric emptying in different positions?
• Which position does promote gastric emptying?
• Is there any difference in physiological parameters and positioning of the neonates?

These questions triggered the need to explore further with a kin intention to find the better position for neonate which will help to fasten the gastric emptying and maintain optimum levels of physiological parameters, hence the study was undertaken.

A quasi-experimental time series design was adopted to conduct the current study from 23.10.2019 to 05.12.2019 in SNCU of Medical College and Hospital, Kolkata, West Bengal, India. Ethical clearance obtained from Institution Ethics Committee, MCH, Kolkata. Formal permission was taken from DHS, DME, Joint DHS (nursing), West Bengal, and MSVP, MCH, Kolkata to conduct the study. Informed consent from the parent was obtained. A sample of 45 preterm neonates were selected for the study by non-probability purposive sampling technique based on the inclusion criteria, those were: Gestational age 30 th-35th weeks, Body weight between 1000 grams to 1400 grams, stable physiological indices, on orogastric tube feeding, feeding through orogastric tube 50-150ml/kg/day,  on gavage feeding with expressed breast milk and exclusion criteria were: Neonates on mechanical ventilation or CPAP,  Having congenital malformation,  having intraventricular haemorrhage, Necrotizing enterocolitis,  pneumothorax, convulsion, intolerance to feeding, unstable vital sign, lactose   intolerance,  asphyxiated neonates, on feeding with human milk fortifier, getting any supplementary nutrition. Data were collected by using record analysis proforma having 5 items, 5 ml disposable syringe, pulse oximeter, physical assessment proforma having 3 items. Validity of the tool was done by 5 experts. Reliability of the tool was done by inter-rater method. The reliability of the tool found in record analysis proforma and in gastric volume record sheet was 0.9, and in physical assessment proforma was 1. The technique of data collection was record analysis, observation, and recording. The selected 45 neonates were randomly assigned into three positions : left lateral position in experimental group I, right lateral position in experimental group II, and supine or any other position in the control group. Personal information and medical information were collected from, patient’s bed head ticket, others history taking sheet and nurses record sheet. The study was carried out for three consecutive days for each neonate. The neonates under study were being fed every 2 hours, as per the unit protocol. And the feeding was given via indwelling orogastric tube made of polyethylene (no.5 and 6fr.). The feeding tube was left in place,  and before every feeding, the fixation and position of the feeding tube was checked. The heart rate, respiratory rate, and oxygen saturation was assessed in  each position before measuring the gastric residual volume without interrupting the neonate’s calm and quiet state, to get the accurate data. The heart rate and oxygen saturation were recorded from the displayed value on the monitor of the pulse oximeter. The respiratory rate was assessed by observing and counting the number of movements of the chest wall and abdominal wall of the neonates for a full one minute. The pre-feed gastric residual volume was aspirated with a sterile 5 ml syringe through orogastric tube, then the aspirated volume reinserted into the stomach. After aspiration the amount was measured and each residual volume was expressed as percentage (%). Each position was given for 2 hours after feed, and after two hours, just before the next feed, heart rate, respiratory rate, oxygen saturation was assessed, and then, the gastric residual volume was measured. Then the gavage feeding was given in prescribed amounts of expressed breast milk. After the feeding again the neonates were placed in left lateral position for experimental group-I and right lateral position for experimental group-II, for next 2 hours. After two hours, the same assessment procedure was followed. On each study day, 2 observations were made and in three consecutive days total six observations in the same positions were made. 

Statistical Analysis

Descriptive statistics were computed to summarize the neonate’s characteristics. ANOVA test was done to compare the mean score of gastric residual volume and physiological parameters.

A repeated measure ANOVA was performed to examine the effects of left lateral positioning and right lateral positioning and days of observation on gastric residual volume and physiological parameters in terms of heart rate, respiratory rate and oxygen saturation. While comparing the gastric residuals with position and days and no. of observation were statistically significant at 0.05 level of significance, there was no significant difference found in relation to positioning with heart rate, respiratory rate, and oxygen saturation.

There is desirable mean and SD of gastric residual volume is lower in right lateral group before 2^nd feed (after 2 hrs of 1^st feed) in day 1, day 2 and day 3 (10.88± 5.04, 9.49± 4.17, 9.65± 4.04) respectively, than (16.14± 6.8, 14.24± 4.98, 12.85± 4.39) in left lateral group. ANOVA was done to show the significant difference in amount of gastric residual volume in day 1, day 2 and day 3 (F=3.290, 4.942, 3.365 respectively) between left lateral and right lateral position. It is shown in table 1.

There is desirable mean and SD of gastric residual volume is lower in right lateral group before 3^rd feed (after 2 hrs of 2^nd feeding) in day 1, day 2 , day 3 (8.74 ± 4.93 , 7.96 ± 3.95 , 7.68 ± 4.41 ) respectively, than (15.90± 5.39,12.68± 4.51,13.94± 4.57 respectively) in left lateral group. ANOVA was done to show the significant difference in amount of gastric residual volume in day 1, day 2 and day 3 (F=8.546, 7.986, 9.620 respectively) between left lateral and right lateral position. It is shown in table 2.

In the table 3, table 4, table 5, table 6, table 7, table 8 it is shown that there was no significant differences in the mean scores of heart rate, respiratory rate, oxygen saturation in relation to left lateral and right lateral positioning on both 1^st and 2^nd observation on day 1, day 2 and day 3.
 

Table 1: A Repeated Measure Analysis of Variance (ANOVA) on Mean, SD of Changes in Gastric Residual Volume (%) of Neonates at Different Times Point on Day 1, 2, 3 in Left Lateral Group, Right Lateral Group, and Control Group.

    n=45

    *Significant at 0.05 Level of Significance

Table 2: A Repeated Measure Analysis of Variance (ANOVA) on Mean, SD of Changes in Gastric Residual Volume (%) of Neonates at Different Times Point on Day 1, 2, 3 (before 3 Rd Feed) in Left Lateral Group, Right Lateral Group, and Control Group.

  n=45

  *Significant at 0.05 Level of Significance 

Table 3: A Repeated Measure Analysis of Variance (ANOVA) on Mean, SD of Changes in Physiological Parameters in Terms of Heart Rate (Before 2^nd Feed) of Neonates at Different Times Point on Day 1, 2, 3 in Left Lateral Group, Right Lateral Group, Control Group.

      n=45

      Not significant at 0.05 level of significance

Table 4: A Repeated Measure Analysis of Variance (ANOVA) on Mean, SD of Changes in Physiological Parameters in Terms of Heart Rate of Neonates, before 3^rd Feed , on Day 1, 2, 3 in Left Lateral Group, Right Lateral Group, Control Group

    n=45

     Not Significant at 0.05 Level of Significance 

Table 5: A Repeated Measure Analysis of Variance (ANOVA) on Mean, SD of Changes in Physiological Parameters in Terms of Respiratory Rate of Neonates, before 2^nd Feed on Day 1, 2, 3 in Left Lateral Group, Right Lateral Group, and Control Group.

    n=45

    Not significant at 0.05 level of significance

Table 6: A Repeated Measure Analysis of Variance (Anova) on Mean, SD of Changes in Physiological Parameters in Terms of Respiratory Rate of Neonates, before 3^rd  Feed on Day 1, 2, 3 in Left Lateral Group, Right Lateral Group, Control Group

    n=45

     Not significant at 0.05 level of significance

Table 7: A Repeated Measure Analysis of Variance (ANOVA) on Mean, SD of Changes in Physiological Parameters in Terms of Oxygen Saturation of Neonates before 2^nd Feed on Day 1,2,3 in Left Lateral Group, Right Lateral Group, and Control Group

        n=45

       Not significant at 0.05 level of significance

Table 8: A Repeated Measure Analysis of Variance (ANOVA) on Mean, SD of Changes in Physiological Parameters in Terms of Oxygen Saturation of Neonates, before 3^rd Feed on Day 1,2,3 in Left Lateral Group, Right Lateral Group, and Control Group

          n=45

        Not significant at 0.05 level of significance.

In the present study desirable mean and SD of gastric residual volume is lower in right lateral group before 2nd  feed (after 2 hrs of 1st feed) in day 1, day 2 and day 3 (10.88± 5.04,9.49± 4.17, 9.65± 4.04) respectively, than in the left lateral group (16.14± 6.8,14.24± 4.98,12.85± 4.39). Gastric residual volume indicates that different body position for neonate have influence on gastric residual volume after feeding. In this study it was found that right lateral group was associated with a significantly lower incidence of gastric residuals as compared to the left lateral group and control group. This study is supported by Kaur V [8]et al., 2018. In this cross over study among 63 neonates, the odds of having gastric residual volume in right lateral position were significantly less as compared to left lateral position [30% Vs 83%;OR (95% CI),0.09(0.04,0.21); p<0.001]. In another study conducted by Hwang SK [6] et al., showed gastric residuals were measured in each position at 30, 60, 90, 120, 150, 180 minutes after feeding. All the positions had highly significant differences in gastric residuals (p<0.001). The study concluded that, placement in right lateral position after feeding could reduce gastric residuals, and thus promotes faster gastric emptying. Effect of position and time were statistically significant by ANOVA (F=5.038, p=0.001; F=429.763, p=<0.001, respectively). Significant differences were there between left lateral and right lateral positions (p=0.023). The present study is also consistent with the result of an experimental study conducted by Emriye Hilal Yayan [9] et al., 2018. It showed that 180 minutes after feeding among prone, supine, right lateral and left lateral positions, in right lateral position the mean gastric residual volume was least (0.38±0.34%) and highest was in left lateral position (1.41±1.22%).Between left lateral and right lateral position significant difference were found (p=0.008). 

The findings related to heart rate showed that there was no significant difference in heart rate of the neonates of left lateral, right lateral and control group before 2nd  feed (after 2 hrs of 1st feed) in day 1, day 2 and day 3 in left lateral, right lateral and control group (F=1.440, 1.972, 1.601 respectively). Before 3rd feeding (after 2 hrs of 2nd feed) findings were (F=2.727, 2.012, 2.815 respectively). The study is supported by Akbarian rad Z [10] (2016).In that study three positions were observed. The mean of heart rate were (148.15± 11.46, 146.09±9.65, 146.02±10.54 in supine, prone and left lateral position). The difference was statistically not significant (p=0.596). Heart rate was normal in all the positions. In another study conducted by Brunheroti MA [11] (2014) compared four positions left lateral, right lateral, prone and supine position to evaluate the effect on cardio-respiratory indicators in preterm neonates on continuous positive airway pressure. No significant difference of heart rate was found between these positions.

The present study findings related to respiratory rate showed that there was no significant difference in respiratory rate of the neonates between left lateral, right lateral and control group before 2nd  feed (after 2 hrs of 1st feed) in day 1, day 2 and day 3 in left lateral, right lateral and control group (F=0.619, 0.407, 0.222  respectively). Before 3rd feeding (after 2 hrs of 2nd feed) findings were (F=0.707, 0.20 7, 0.779 respectively). The study, supported by Brunheroti MA [11], (2014) found no significant difference of respiratory rate between left lateral and right lateral position. In another meta-analysis done by Bredemeyer SL [12] (2004, among 66 infants) compared left lateral and right lateral position and found no significant difference for apnoea (MD-0.42, 95%CI-1.10 to 0.57).One more study done by Bredemeyer SL (2004, among 45 infants) also showed no significant difference of severe apnoea (MD 0.01, 95%CI-0.40 to 0.42).The study is contradicted by Yin T [13]et al., (2016). That study compared supine, semi-prone and lateral position and results showed that there is significant variability in respiratory rate (OR=0.68; CI 0.51-0.89). The lateral position was associated with increased respiratory rate (B=2.9; p=0.02).

The present study findings showed no significant difference of oxygen saturation between left lateral, right lateral position done by ANOVA. The results were, before 2nd feed (after 2 hrs of 1st feed) in day 1, day 2 and day 3in left lateral, right lateral and control group (F=0.446, 1.206, 3.022 respectively). Before 3rd feeding (after 2 hrs of 2nd feed) findings were (F=0.007, 0.247, 1.882 respectively). This findings are supported by Akbarian Rad Z¹⁰ (2016) found no significant difference between prone position and left lateral position (97.41±1.91 and 96.14±2.36) p=0.596. Abdeyazdan [14] et al., (2015) found no significant difference of oxygen saturation between prone, supine and left lateral position. One study by Bredemeyer SL¹² (2004, among 45 infants) showed no significant difference of oxygen saturation between left lateral and right lateral position (MD 0.42, 95% CI-2.42 to 3.26).

The findings of the present study confirm that the placement of the neonate in the right lateral position after feeding could reduce gastric residuals thus improve gastric emptying. On the other hand physiological parameters in terms of heart rate, respiratory rate and oxygen saturation in left lateral position, right lateral position and supine position are the same. So, from the findings it can be concluded that right lateral position after feeding improves gastric emptying but has no effect on heart rate, respiratory rate and oxygen saturation.

Abbreviations

SNCU: Sick Newborn Care Unit, NICU: Neonatal Intensive Care Unit

Acknowledgements

The authors thank the authorities of MCH, Kolkata, West Bengal as well as the SNCU staff. They also thank the parents of the newborns participating in the study.

Funding: No funding sources 

Conflict of interest: None declared

Ethical approval: The study was approved by the Institutional Ethics Committee of Medical College and Hospital, Kolkata, West Bengal.

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