Neuromodulation of Limb Proprioceptive Afferents Using a Vibratory Device to Decrease Apnea, Intermittent Hypoxia and Bradycardia of Prematurity.

Aim: To study the effect of limb proprioceptive stimulation using a vibratory device on apneic events, intermittent hypoxic episodes and bradycardias in a premature infant with apnea of prematurity.

The objective is to provide support and to assist impaired ventilation and oxygenation in apnea of prematurity (AOP). Recurrent apnea and accompanying resultant intermittent hypoxic (IH) episodes are significant concerns commonly encountered in premature infants, and optimal management is a challenge to neonatologists. AOP is defined as "a pause of breathing for more than 15-20 seconds or accompanied by oxygen desaturation (SpO2<80% for>4s) and bradycardia (heart rate<2/3 of baseline for>4s), in infants born less than 37 weeks of gestation [Moriette G et al., 2010]. When these pauses are longer (> 15s), they are frequently prolonged by obstructed inspiratory efforts, most likely secondary to loss of upper airway tonic activity [Martin RJ et al., 2012]. In extremely low birth weight (ELBW) infants, the incidence of IH progressively increases over the first 4 weeks of postnatal life, followed by a plateau and subsequent decline between 6-8 weeks.

The incidence of AOP correlates inversely with gestational age and birth weight. Nearly all infants born <29 weeks gestation or <1,000 g [Robertson CM et al., 2009], 54% at 30 to 31 weeks, 15% at 32 to 33 weeks, and 7% at 34 to 35 weeks gestation exhibit AOP [Martin RJ et al]. Both animal and human evidence show that immature or impaired respiratory control and the resultant IH exposure contribute to a variety of pathophysiologic issues via pro-inflammatory and/or pro-oxidant cascade as well as cellular mechanisms, e.g., apoptosis, leading to acute and chronic morbidities (e.g. retinopathy of prematurity, altered growth and cardiovascular regulation, disrupting zinc homeostasis which hampers insulin production and there by predisposing to diabetes in later life, cerebellar injuries and neurodevelopmental disabilities) [Martin RJ et al., 2004, Pae EK et al., 2011, 2014, ].

Current standard of care for AOP includes prone positioning, continuous positive airway pressure (CPAP) or nasal intermittent positive pressure ventilation (NIPPV) to prevent pharyngeal collapse and alveolar atelectasis, and methylxanthine therapy (caffeine, theophylline), which is the mainstay of treatment of central apnea [Reher et al., 2008; Pantalitschka T et al., 2009; Moretti C et al., 2012; Henderson-Smart DJ et al., 2010]. Apart from prone positioning, none of these interventions are optimal for early development. CPAP masks will distort the bony facial structure in early development, and methylxanthine interventions pose serious questions of neural development interactions.