Estimating Umbilical Venous Catheter Insertion Depth in Newborns Using Weight or Body Measurements: A Multicenter Randomized Clinical Trial

I.Project Summary In this randomized clinical study, who are hospitalize in the neonatal intensive care unit pediatric department of King Salman Armed Forces Hospital Northwestern Region KSA Neonates who require umbilical venous catheter (UVC) insertion during their NICU admission will be randomized to one of the 2 formulas 1) umbilicus to the nipple in cm minus 1 (UN - 1) or 2) and birth weight based formula (1.5×birth weight (Kg) + 5.6) for estimation of the pre-insertion UVC depth. UVC will be inserted under sterile condition as per our unit protocol. Then to determine the UVC tip position, anteroposterior and lateral a thoracoabdominal radiograph will be taken.

II.Introduction Umbilical vessel catheterization of newborns was used for more than 60 years (1,2).The ideal position of UVC tip to decrease complications is outside the heart at the junction of inferior vena cava and right atrium (3). UVC related complications are mainly due to catheter malposition as pericardial effusions , cardiac tamponade and cardiac thrombus have been reported with UVCs whose tips lay within the heart (4). There is no definite rule describe how far umbilical catheters should be inserted in the umbilical vein; different methods including the Dunn method, Shukla-Ferrara, modified Shukla-Ferrara and umbilicus to the nipple formulae are used (5). Selection of the most correct methods is very important in terms of decreasing th risk and frequency of complications (6,7). IN KFMC NICU and Alyamah NICU and Pediatric department of King Salman Armed Forces Hospital Northwestern Region KSA , the most commonly used method for estimation of UVC insertion length is the birth weight based formula (3× birth weight (Kg) +9)/2. A recent retrospective study reported that 57% accuracy rate with birth weight based formula(8). In our units no audit done for accuracy rate of UVC dependent on birth weight based formula endpoint

The endpoint measurement of UVC tip determined by anteroposterior x ray (12,13) to check where is the tipe of UVC located that is used in our unit

III.Project Objectives

Research Questions: Does the estimating insertion depth using umbilicus to the nipple in cm minus 1 (UN - 1) formula more accurate than a birth weight-derived formula resulted in more correctly placed umbilical venues catheters.

Primary objective: to compare accuracy rate between UVC insertion length estimated by using 1)umbilicus to the nipple distance in cm minus 1 (UN - 1) formula and 2) Shukla's exact birth weight based formula (3× birth weight (Kg) +9)/2to determine optimum UVC tip position compared against the standard accepted level UVC tip at the level of the diaphragm or the upper border of the 9th and the lower border of the 10th thoracic vertebrae (T9-T10) on the anteroposterior and lateral X-ray Secondary objective: to compare the accuracy rate of UVC tip position between two formulae depend on appropriation of baby to gestational age (AGA, SGA, LGA) AGA: appropriate for gestational age (i.e birth weight between 10th and 90th percentile for gestational age); SGA: Small for gestational age (i.e. birth weight \<10th percentile for gestational age); LGA: large for gestational age (i.e. birth weight >90th percentile for gestational age)

IV.Literature Survey/Background Insertion of umbilical venous catheters in newborns admitted to hospital in neonatal intensive care units (NICU) who are preterm or have severe morbidity is a commonly used method for Venus access to maintain fluid support , parenteral nutrition ,administration of blood products, , administration of antibiotic , exchange transfusion and investigations, as well as providing emergency intravenous access (9). Ideally, umbilical venous catheters are placed under guidance of imaging methods. However, umbilical venous catheters are placed without any imaging method in emergency cases in NICUs. This leads to frequent occurrence of malposition of UVC (10,11). The commonly used formulas to estimate the depth of umbilical catheter include a birth weight based formula proposed by Shukla and Ferrara and Dunn's shoulder to umbilical length graph. In our units in the neonatal intensive care unit of KFMC / Al Yamamh Hospital KSA , the most commonly used method for estimation of UVC insertion length is the exact birth weight based formula (3× birth weight (Kg) +9)/2)(14). A recent retrospective study reported a distance from base of umbilicus to nipple distance (UN)-1 cm formula consider best and most accurate insertion depth of UVC with accuracy rate of 84% compared with 57% accuracy rate with birth weight based formula(8). In the literature, few studies have compared the two methods in determining how far umbilical catheters should be inserted in the umbilical vein