Accuracy of 11 formulae to guide umbilical arterial catheter tip placement in newborn infants

Indications, Measurements, and Complications of Ten Essential Neonatal Procedures

About 10% of newborns require some degree of assistance to begin their breathing, and 1% necessitates extensive resuscitation. Sick neonates are exposed to a number of invasive life-saving procedures as part of their management, either for investigation or for treatment. In order to support the neonates with the maximum possible benefits and reduce iatrogenic morbidity, health-care providers performing these procedures must be familiar with their indications, measurements, and potential complications. Hence, the aim of this review is to summarise ten of the main neonatal intensive care procedures with highlighting of their indications, measurements, and complications. They include the umbilical venous and arterial catheterizations and the intraosseous line which represent the principal postnatal emergency vascular accesses; the peripherally inserted central catheter for long-term venous access; the endotracheal tube and laryngeal mask airway for airway control and ventilation; chest tube for drainage of air and fluid from the thorax; and the nasogastric/orogastric tube for enteral feeding. Furthermore, lumber puncture and heel stick were included in this review as very important and frequently performed diagnostic procedures in the neonatal intensive care unit.

A novel and accurate method for estimating umbilical arterial and venous catheter insertion length

OBJECTIVE

To develop a novel, rapid, and more accurate model for estimating umbilical arterial (UAC) and venous catheter (UVC) insertion length.

STUDY DESIGN

We evaluated UACs and UVCs from a retrospective cohort to determine the rate of correct initial positioning based on conventional birth weight-based equations utilized in our neonatal intensive care unit. We then derived new equations, developed the mobile application, UmbiCalc, to simplify implementation of the new equations, and validated their accuracy with prospective utilization.

RESULTS

The conventional equations successfully predicted insertion length in 69% (364 of 524) of UACs and only 36% (194 of 544) of UVCs. Our new model was prospectively applied to 68 UAC and 80 UVC placements with successful initial positioning achieved in 90% [95% CI, 80.2-94.9] and 76% [95% CI, 65.9-84.2], respectively.

CONCLUSIONS

Our novel approach more accurately estimates UAC and UVC insertion length.

Estimating insertion length of umbilical arterial and venous catheters in newborn infants: time for change

BACKGROUND

Umbilical catheters are inserted through the umbilical artery or vein at birth and are crucial in neonatal care. There are several different methods of estimating adequate insertion length of umbilical catheters based on one of two hypotheses; that the insertion length of the UC is correlated to either the infant's birth weight or an external length measurement.

AIM

To review the published literature on methods of estimating insertion lengths of umbilical arterial catheters (UACs) and umbilical venous catheters (UVCs) in newborn infants.

METHODS

Systematic search on Medline was undertaken using keywords for relevant papers up to March 2019. Papers were selected by manual search of titles and abstracts.

RESULTS

Formulae for predicting umbilical catheter insertion length are unreliable, particularly for UVCs. There is also conflicting evidence around whether birth weight-based formulae are more reliable than external length-based formulae. Studies comparing various methods to determine their efficacy to show that current formulae have a low accuracy for determining both UVC and UAC positioning.

CONCLUSIONS

Current formulae for estimating insertion length of umbilical catheters are not fit for purpose. We propose a new observational study which uses a new external length measurement, the sternal notch to umbilicus length, to develop a more reliable formula for the insertion of UVC and UAC to an adequate length.

Predicting the optimal depth of ultrasound-guided right internal jugular vein central venous catheters in neonates

BACKGROUND

Poor positioning of a central venous catheter (CVC) can cause severe complications. The objective is to create a formula that predicts the optimal insertion depth of a real time ultrasound-guided CVC in the right internal jugular vein (RIJV) in newborns.

METHODS

Between 2015 and 2017, 91 newborns that required a CVC were included in a prospective observational study. Variables such as gestational age, gender, weight, height, and neck length were studied. On the chest x-ray, the distance between the insertion site on the skin and the catheter tip was measured.

RESULTS

Of the patients included, 50 (54.9%) were males and 40 (44.4%) females; 64 (70.3%) were preterm. Mean gestational age was 33.44 (25 to 41) weeks, weight 2020 (580 to 3980) g, and height 43.04 (26 to 53) cm. Variables were correlated with catheter length and an algorithm was modeled for the introduction method, in which the highest corrected determination coefficient was obtained for weight (R² = 0.723).

CONCLUSION

This study demonstrated that the weight of the newborn was the most significant individual predictor of optimal insertion depth of a CVC in the RIJV. The formula Y = 2.6 + 0.7 (weight in kg) that we suggest is practical and reproducible.

LEVEL OF EVIDENCE

Level IV.

Learning Curves for Training in Ultrasonography-Based Examination of Umbilical Catheter Placement: A Piglet Study

BACKGROUND

The training required for accurate assessment of umbilical catheter placement by ultrasonography (US) is unknown.

OBJECTIVE

To describe the learning curve and provide an estimate of the accuracy of physicians' US examinations (US skills) and self-confidence when examining umbilical catheter tip placement.

METHODS

Twenty-one physicians with minimal experience in US completed a 1.5-hour eLearning module. Ten piglets with catheters inserted in the umbilical vessels were used as training objects. Following eLearning each physician performed up to twelve 10-min US examinations of the piglets. Expert examinations were reference standards. Sensitivity and specificity of physicians' skills in detecting catheter tip placement by US was used to describe the learning curve. Self-confidence was reported by Likert scale after each examination.

RESULTS

Physicians' detection of a correctly placed and misplaced umbilical artery catheter tip increased by an odds ratio of 1.6 (95% CI: 1.1, 2.3) and 3.6 (95% CI: 1.7, 7.8) per examination performed. A sensitivity of 0.97 (95% CI: 0.80, 0.99) and specificity of 0.95 (95% CI: 0.84, 0.99) was reached after 6 examinations. For the venous catheter, US skills in detecting a misplaced catheter tip increased with an odds ratio of 2.4 (95% CI: 1.2, 4.8) per US examination. Overall, performance and self-confidence plateaus were reached after 6 examinations.

CONCLUSION

We found steep learning curves for targeted US examination of umbilical catheter placement. eLearning followed by 6 examinations was found to be adequate training to perform with a sufficiently high accuracy and self-confidence to allow for point-of-care use.