ett_size_by_age {physiology}

Estimate appropriate size of endotracheal tube for infants and children

Description

ett_size_cole uses the classic Cole formula for uncuffed tubes, Motoyama formula for cuffed tubes with age over two years, and the Khine formula for cuffed tubes with age under two years. All of these, as any anesthesiologist will tell, give poor estimates at any extreme of age, or height. These formulae are for use in pediatric practice only.

Usage

ett_size_by_age(age_y, cuffed = TRUE)

Arguments

age_y

numeric vector

cuffed

logical vector, single value, or a vector of the same length as the given age vector, defining whether the desired tube is to be cuffed. If not specified, then it is assumed that a cuffed tube is used.

Value

ETT size, internal diameter in mm, rounded to nearest half-mm size up to 6mm, then the nearest integer.

References

http://anesthesiology.pubs.asahq.org/Article.aspx?articleid=1933172

See Also

Other airway equipment: deadspace_things_ml, deadspace_total, ett_vol_ml

Examples

teenagers <- ett_size_by_age(13:18)
plot(13:18, teenagers,
  main = "This formula for ETT tube size overestimates tube
  sizes of teenagers, and takes no account of gender")
lines(13:18, teenagers)
ages <- c(1/12, 1, 2, 4, 7, 11)
neonate_to_child <- ett_size_by_age(age = ages)
names(neonate_to_child) <- ages
print(neonate_to_child)
plot(ages, neonate_to_child)
lines(ages, neonate_to_child)
plot(ages, neonate_to_child, log = "x")
lines(ages, neonate_to_child)