Estimation of a Suitable Nasotracheal Tube Length for Infants and Children

Abstract

SUMMARY A method for the predetermination of die safe lengdi of nasotracheal tubes in infants and children is presented. The distance from die nostril to die carina was found to correlate better widi the height than widi die body weight, surface area or age of the patient. The investigation was made by measuring die inserted lengdis of die tubes at extubation and die distance between die tube tip and the carina in radiographs in 200 infants and children. In die statistical analysis, die equation for die regression line was: nostril‐carina distance (cm) = 0.16 × height (cm) + 4.5 (cm), die standard error s̄=± 1.2 cm and die correlation coefficient 0.96 (R2). The importance of predetermination of die tube lengtii in prolonged intubation is emphasized. ZUSAMMENFASSUNG Es wird eine Mediode zur Vorausbestimmung einer Sicherheitslänge nasotrachealer Tuben für Sauglinge und Kinder vorgestellt. Die Korrelation des Abstandes zwischen Nasenloch und Carina war zur Körpergrösse besser als zum Körpergewicht, zur Körperoberfläche oder zum Alter des Patienten. Für diese Untersuchung wurde bei 200 Säuglingen und Kindern der Abstand zwischen Tubusende und Carina im Röntgenbild sowie die Länge des eingeführten Tubusanteiles anlässlich der Extubation gemessen. Für die Regressionslinien wurde in der statistischen Anlyse die nachstehende Gleichung verwendet: Nasenloch‐Carina‐Abstand (in cm) = 0,16 × Körpergrösse (in cm) + 4,5 (cm). Die Standardabweichung s̄ war ± 1,2 cm, der Korrelations‐Koeffizient 0,96 (R2). Auf die Bedeutung der Vorausbestimmung der richtigen Tubuslange für die Langzeitintubation wird nachdrucklich hingewiesen.

Nares‐to‐carina distance in children: does a ‘modified Morgan formula’ give useful guidance during nasal intubation?

“…The dotted line in panel c shows the findings of Mattila et al . : NC in cm = 0.16 × height + 4.5 . The dashed line is the Morgan formula modified for nasotracheal intubation: Intubation depth at nares in cm = 0.12 × height + 5.…”

“…The key findings are that NC distance is best predicted from patient height/length, and that a modified Morgan formula gave acceptable guidance for ETT placement in infants and children.…”

“…In 1971, Mattila et al . measured NC distance in 200 children and reported a close relation between NC distance and height/length, but the study has not received much attention. The first objective of the study was therefore to re‐examine the relationship between NC distance and growth parameters.…”

The intubation depth marker: the confusion of the black line

“…There are various formulae which correlate airway lengths (incisors to mid‐trachea) and height, weight and age of the child (1,16,17). One can then use the length or centimetre markings suggested by Mattila (18) with these formulae as a guide.…”

Foot length, an accurate predictor of nasotracheal tube length in neonates

“…We attempted to limit this effect by measuring tracheal lengths in situ before its attachments were severed. Observations at bronchoscopy in live infants,16and radiological evaluations6 12 have been used to provide in vivo airway dimensions, but these studies have not included small premature infants limiting their application to current neonatal practice.…”