Background: The Medoff-Cooper Nutritive Sucking Apparatus (M-CNSA) has been used to objectively measure sucking maturation in preterm infants. The M-CNSA is able to accurately detect sucking pressures less than 20mmHg, however lower pressure thresholds have not previously been used in research.
Aims: To determine if differences are observed in the number of sucks and maturation in the number of sucks over time when the minimum pressure threshold used to detect a suck is 7mmHg compared to 20mmHg using the M-CNSA.
Study design: Descriptive.
Subjects: A convenience sample of 171 healthy premature infants born between 29 and 34weeks gestational period who were part of a larger randomized controlled study.
Outcome measures: The number of sucks detected during weekly five-minute oral feeding observations using 7mmHg and 20mmHg.
Results: Significantly more sucks were detected using the 7mmHg vs 20mmHg threshold at all time points. At both pressure thresholds, the mean number of sucks detected during the five minute feeding observation increased over time. The difference in the number of sucks detected at 7 and 20mmHg did not change over time (p=0.50).
Conclusions: Using the lower threshold of 7mmHg compared to 20mmHg resulted in more sucks detected while consistently measuring improvement in sucking over time. Detection of more sucks and sucks at a lower pressure threshold allows clinicians and researchers to more accurately assess oral feeding skills among premature infants.
Keywords: Microstructure of infant sucking behaviors; Nutritive sucking pressures; Preterm infants; Sucking skills.