Estimating Insertion Length of Umbilical Catheters in Newborn Infants

• Research type

  Research Study

• Full title

  Developing novel formulae for estimating insertion length of umbilical venous and arterial catheters in newborn infants

• IRAS ID

  236837

• Contact name

  Mallinath Chakraborty

• Contact email

  chakrabortym@cardiff.ac.uk

• Sponsor organisation

  Cardiff and Vale University Health Board

• Clinicaltrials.gov Identifier

  EudraCT, 2018-000020-33

• Duration of Study in the UK

  1 years, 11 months, 29 days

• Research summary

  Summary of Research
  The study initially started in a single centre but was expanded in 2019 to include two other centres in South Wales. Recruitment for the study was interrupted by the Covid-19 pandemic, and the end date was extended to the end of 2021.
  During the course of the study, a total of 167 infants were recruited from three centres. Of these, 114 had an arterial catheter inserted while 113 had a venous catheter inserted. One infant had missing data for UAC insertion and had to be excluded from the study. Thus, 113 infants were included per catheter in the final analysis.
  Our prospective multi-centre observational study identified a quadratic model based on birthweight to be the best fit for estimating the insertion length of umbilical lines in neonates. Of note, our original hypothesis – an external distance between two anatomically fixed points would better predict internal length – was disproved.
  The study initially started in a single centre but was expanded in 2019 to include two other centres in South Wales. Recruitment for the study was interrupted by the Covid-19 pandemic, and the end date was extended to the end of 2021.
  During the course of the study, a total of 167 infants were recruited from three centres. Of these, 114 had an arterial catheter inserted while 113 had a venous catheter inserted. One infant had missing data for UAC insertion and had to be excluded from the study. Thus, 113 infants were included per catheter in the final analysis.
  Our prospective multi-centre observational study identified a quadratic model based on birthweight to be the best fit for estimating the insertion length of umbilical lines in neonates. Of note, our original hypothesis – an external distance between two anatomically fixed points would better predict internal length – was disproved.
  Insertion Length of Umbilical Catheters

  Umbilical catheters, inserted through the umbilical artery and vein of newborn babies at birth, are crucial in neonatal care of sick babies. They allow delivery of medication and fluids and to provide access for blood sampling and blood pressure monitoring. Incorrect positioning of the catheter tip due to under- or over-insertion length can lead to significant complications in newborn infants. Currently, several methods are used to estimate insertion length of umbilical catheters based on one of two beliefs; that the insertion length of the umbilical catheter is proportional to either the infant’s birth weight or an external length measurement.

  Several research studies have identified that existing methods often result in incorrect positioning of umbilical catheters, with studies showing a variable range of proportions of umbilical lines being correctly or incorrectly placed. In particular, formulas for predicting umbilical venous catheter (UVC) length have been shown to be particularly unreliable.

  We propose a new observational study which uses a novel but easy-to-measure external length measurement, the sternal notch (upper end of breast-bone) to umbilicus (upper margin of belly-button) length, along with other clinical information to develop a more reliable formula for estimating the insertion length of umbilical venous and arterial catheters to an appropriate length.

  Our study population will include newborn babies admitted to the neonatal unit requiring umbilical venous (UVC) and/or arterial catheterisation (UAC) over a two-year period. Demographic information will be recorded for each child and once position has been confirmed, the new external length will be measured. New formulae for estimating required insertion length will be developed using statistical (regression) analysis.

  Summary of results
  The study initially started in a single centre but was expanded in 2019 to include two other centres in South Wales. Recruitment for the study was interrupted by the Covid-19 pandemic, and the end date was extended to the end of 2021.
  During the course of the study, a total of 167 infants were recruited from three centres. Of these, 114 had an arterial catheter inserted while 113 had a venous catheter inserted. One infant had missing data for UAC insertion and had to be excluded from the study. Thus, 113 infants were included per catheter in the final analysis.
  Our prospective multi-centre observational study identified a quadratic model based on birthweight to be the best fit for estimating the insertion length of umbilical lines in neonates. Of note, our original hypothesis – an external distance between two anatomically fixed points would better predict internal length – was disproved

• REC name

  Wales REC 1

• REC reference

  18/WA/0117

• Date of REC Opinion

  5 Apr 2018

• REC opinion

  Favourable Opinion