Orotracheal tube insertion in extremely low birth weight infants.

Thirty-one consecutive infants <1000 g at birth were intubated according to Tochen's rule; placement was verified/modified after auscultation and by radiology. Depth measurements were by caliper and radiology. Tochen's rule alone would lead to inadequate tube placement in 47% of infants. Auscultation allows adequate placement in only three-fourths of patients.