Oral and nonoral sensorimotor interventions facilitate suck-swallow-respiration functions and their coordination in preterm infants

Abstract

Background: Preterm infants are at high risk of encountering oral feeding difficulties. Early sensorimotor interventions may improve oral feeding skills in preterm infants.

Aim: To further explore the effects of an oral (O), tactile/kinesthetic (T/K), and combined (O+T/K) sensorimotor intervention on preterm infants' nutritive sucking, swallowing and their coordination with respiration.

Study design: Seventy-five infants (29 [0.3, standard error of mean, SEM] weeks gestation, 49 males/26 females) were randomly assigned to an O group involving sensorimotor input to the oral structures; a T/K group involving sensorimotor input to the trunk and limbs; a combined (O+T/K) group; and a control group.

Outcome measures: Stage of sucking, suction and expression amplitudes (mmHg), suck-swallow ratio, stability of suck-swallow interval, and swallow-respiration patterns.

Results: The O group had significantly more advanced sucking stages, and greater suction and expression amplitudes than controls [p≤0.035, effect size (ES) >0.6]. The suck-swallow ratio and stability of suck-swallow intervals did not significantly differ among groups (p≥0.181, ES≤0.3). The three interventions led to fewer swallows bracketed by prolonged respiratory pauses compared to controls (pause-swallow-pause, p≤0.044, ES≥0.7). The T/K and combined (O+T/K) groups had greater occurrence of swallows bracketed by expiration than the control and O groups (expiration-swallow-expiration, p≤0.039, ES≥0.3).

Conclusion: The O intervention enhanced specific components of nutritive sucking. All three interventions resulted in improved swallow-respiration coordination. Sensorimotor interventions have distributed beneficial effects that go beyond the specific target of input.

Figure 1

Swallow-respiration patterns. Pattern 1 - start inspiration-swallow-end expiration (start I-Sw-end E); pattern 2 - inspiration-swallow-inspiration (I-Sw-I); pattern 3 - end inspiration-swallow-start expiration (end I-Sw-start E); pattern 4 - expiration-swallow-expiration (E-Sw-E); pattern 5i - swallow interrupts inspiration (Sw-interrupt I); pattern 5e - swallow interrupts expiration (Sw-interrupt E); and pattern 6 - pause-swallow-pause (P-Sw-P, swallows occurring at cessation of respiration ≥ 2 seconds).

Figure 2

Sample tracing of swallow-respiratory movements (pressure changes during respiration) recorded from one infant during oral feeding, demonstrating, the pause-swallow-pause pattern (P-Sw-P), and expiration-swallow-expiration pattern (E-Sw-E).