Strobel et al used a child's height to estimate the length of the esophagus. This can be used to insert a pH probe into the esophagus to measure reflux. The authors are from the UCLA Center for the Health Sciences.
Patient selection: males and females from 3 weeks of age to 19.6 years. Since a person should have achieved adult height by 19.6 years, the estimate can be used for adults without significant height shortening.
The esophageal length is from the lower esophageal sphincter to the maxillary incisors. Thus the length given is not the true esophageal length per se but rather the distance that the tubing is inserted. This explains the presence of different equations depending on whether the tubing is inserted orally or nasally.
Note: Each estimated is "corrected" to "decrease the likelihood of a false positive Tuttle test" (Tuttle test= pH probe test).
esophageal length in cm for oral tubing =
= (0.226 * (standing body height in cm)) + 6.7
corrected esophageal length in cm for oral tubing =
= (0.226 * (standing body height in cm)) + 6.7 - 3.1 =
= (0.226 * (standing body height in cm)) + 3.6 =
esophageal length in cm for nasal tubing =
= (0.252 * (standing body height in cm)) + 5.0
corrected esophageal length in cm for oral tubing =
= (0.252 * (standing body height in cm)) + 5.0 - 4.1 =
= (0.252 * (standing body height in cm)) + 0.9 =
As shown by Day et al in Figure 1, the raw estimate from the oral tubing equation is about 3 cm greater than that directly measured. The correction factor given actually takes this into account.
