OBJECTIVE. The goal of this investigation was to determine how current parenteral nutrition and enteral nutrition practice intentions for preterm infants compare with published recommendations and previous feeding practices.
METHODS. A survey of feeding strategies for 3 preterm infant weight groups was sent to NICU directors, neonatal fellowship directors, neonatologists, neonatal nurse practitioners, and neonatal dieticians. A total of 775 surveys were distributed by both electronic and standard mail services.
RESULTS. There were 176 survey responses (23%). The majority of practitioners initiated parenteral nutrition for very preterm infants in the first day of life. Ninety-one percent of respondents increased protein delivery daily. Most respondents increased lipid delivery at a fixed rate, rather than on the basis of triglyceride levels. Insulin was used in 98% of units, but only 12% of the time as a nutritional adjuvant to increase weight gain. Across all birth weight categories, breast milk was prescribed most commonly for the first enteral feeding. Enteral feedings were started earlier and increased faster than in the past, especially for extremely low birth weight infants (<1000 g). The majority of respondents prescribed enteral feedings for infants with indwelling umbilical arterial (75%) and umbilical venous (93%) catheters. Despite data that more rapid feeding advancement is safe, >80% of respondents increased feedings at rates of 10 to 20 mL/kg per day across all weight categories.
CONCLUSIONS. Clinicians reported that they are initiating parenteral and enteral nutrition earlier and in larger volumes than in the past, reflecting increased knowledge about best nutritional practices in very preterm neonates. The data suggest that the persistent extrauterine growth failure of preterm infants is not attributable to a lack of best nutritional practice knowledge and intention.
To the Editor,
I read with great interest the article by Hans et al (1) reporting the results of the 2006 Neonatal Nutrition Survey. This survey aimed to assess the nutritional practices in the neonatal intensive care units throughout the United States. This study is certainly of interest but I have several major concerns about the conclusions of the authors.
My first concern relates to the first conclusion which states that the data reflect an increase knowledge about best nutritional practices for preterm infants. This conclusion may be, in fact, completed flowed by the low rate of answers (i.e., 23%). When a mail questionnaire is used as the data collection device, response rate is a primary concern since an inadequate response jeopardizes the randomness or representativeness of the sample and thus the ability to estimate population values. It is well known that survey non-response can bias samples (and therefore survey data) by making the sample composition substantively different from the target population. Bias, in this instance, refers to the difference between the sampled units and the target population. The biasing effect of non-response can be greater as the response rate drops and, therefore, researchers should seek higher response rates to decrease the likelihood of non-response bias. However, survey error resulting from non-response will only occur when there are significant differences between respondents and non-respondents. The problem for survey researchers is, therefore, understanding when non-response will not cause survey error and when it will introduce bias that will affect data reliability–that is, under which conditions are respondents and non-respondents most likely to differ? Unfortunately, the authors did not address the non-response issue adequately in order to increase confidence in data quality despite several methods are available (2). Therefore, in absence of more precise information on the quality of the data, one might postulate that the physicians interested in nutrition where more prone to answer the survey. Therefore, the apparent increase in knowledge about best nutritional practices for preterm infants may be a true statement but only for a selected group of physicians.
My second concern relates to the presentation of the data themselves. As an example, the data presented in Table 2 suggest that prescribed parenteral protein for low-birth-weight infants are, nowadays, appropriate and close to the recommendations. However, it clear from the table that some physicians still 1) prescribe protein on day 1 at a much lower level than recommended (i.e.; 0.5 g/kg.d), 2) increase protein intake at a low rate (i.e.; 0.25 g/kg.d) and 3) have a target intake for protein lower than recommended (i.e., 2.5 g/kg.d). It would have been of interest for the reader to have the proportion of the physicians who prescribe below the recommendations for each nutrient.
My third concern relates to the last conclusion of the authors which states that the data also “suggest that the persistent extrauterine growth failure of preterm infants is not attributable to a lack of best nutritional practice knowledge and intention”. No data in this manuscript support this conclusion and, if there is a major non-respondent bias, as discussed above, this conclusion is likely to be inaccurate. Furthermore, the data reported in this manuscript demonstrate that the smaller the infant, the lower are the nutritional intakes. This is a major issue, since the smallest infants have the highest nutritional requirements and the highest rate of extrauterine growth retardation (3). It is therefore likely that the persistent extrauterine growth failure of extremely low birth weight infants is still attributable to a lack of best nutritional practice knowledge and intention in this group of infants. Finally, the only data on which the authors rely there statement are data published in 2003 (3) but collected in the 90s, which was somewhat before the most recent nutritional recommendations. This highlights, however, the need for more recent growth surveys in very-low-birth-weight infants.
As a comparison, we performed a similar survey in France also in 2006 (4). The response rate of the physicians from the level III units was 85%. Our study confirms the improvement in the neonatologists’ understanding and knowledge of the nutritional needs of preterm infants. In comparison with recent guidelines for parenteral nutrition for preterm infants, our results indicate that the majority of the neonatal departments are familiar with target macronutrient and energy intakes, but that the time of introduction and the rate of progression of macronutrients, particularly proteins and lipids, are frequently lower than those defined by the guidelines. Furthermore, our study demonstrated a marked heterogeneity between neonatal units and, therefore, confirms the marked difference between centers for the nutritional management of neonates.
In conclusion, we believe that large-scale publication of new nutritional guidelines for the parenteral nutrition of neonates and preterm infants as well as regular, specific training in the parenteral nutrition of preterm infants are still needed and we are concern that the apparent, but maybe not universal, increase knowledge about best nutritional practices for preterm infants reported in the manuscript of Hans et al (1) may annihilate the recognition of a need for a specific training in neonatal nutrition.
References 1. Hans DM, Pylipow M, Long JD, Thureen PJ, Georgieff MK. Nutritional practices in the neonatal intensive care unit: analysis of a 2006 neonatal nutrition survey. Pediatrics. 2009 Jan;123(1):51-7. 2. Groves RM. Nonresponse rates and nonresponse bias in household surveys. Public Opinion Quarterly 2006 70:646-675 3. Dusick AM, Poindexter BB, Ehrenkranz RA, Lemons JA. Growth failure in the preterm infant: can we catch up? Semin Perinatol. 2003;27:302–310 4. Lapillonne A, Fellous L, Mokhtari M, Kermorvant-Duchemin E. Parenteral nutrition objectives for very low birth weight infants: results of a national survey. J Pediat Gastroenterol Nutr 2009;48:618–626.
Conflict of Interest:
None declared