Swallowing, feeding, developmental outcomes and associated factors of South African infants with hypoxic-ischaemic encephalopathy

Abstract

Background: Hypoxic-ischaemic encephalopathy (HIE) is a significant cause of mortality and neurological impairment among infants, especially in low- and middle-income countries (LMICs). Associated problems may include swallowing, feeding, and developmental difficulties but there is a lack of research in the field. Aim: To describe South African infants with HIE regarding swallowing, feeding, development and associated factors. Method: Three prospective studies were conducted at an academic hospital in Tshwane over 24 months. Data were collected in the 29-bed neonatal unit and developmental assessments were conducted on an outpatient basis. Firstly, a comparative design described and compared factors associated with mild and moderate HIE among 46 infants. Secondly, a longitudinal cohort design described the evolution of swallowing and feeding among 29 infants with all stages of HIE initially and at discharge from hospital. Correlational research explored the relationship between oropharyngeal dysphagia (OPD) severity and length of hospitalisation. Thirdly, a case series described the swallowing and feeding of four infants with moderate HIE and their development at six and 12 months. Results and discussion: Management factors and clinical tests differed significantly between mild and moderate HIE in Study 1. Significant factors included resuscitation duration (p=0.011); time to spontaneous respiration (p=0.012); admission and highest Thompson scores (p<0.001); and five- (p=0.012) and ten-minute (p=0.022) APGAR scores. Approximately two-thirds of Study 2 participants displayed OPD symptoms regardless of HIE severity, suggesting that infants with all grades of HIE should receive early intervention by a speech-language therapist (SLT). Significantly fewer OPD symptoms occurred at discharge compared to initial assessment (p=0.004). The correlation between OPD severity and length of hospitalisation was not significant (p=0.052). All participants with moderate HIE in Study 3 displayed atypical outcomes throughout infancy, including OPD during hospitalisation. Everyone went home on oral feeds, but some breastfeeding difficulties persisted due to non-optimal states of alertness and aspiration on fast-flowing liquids. Developmental delays emerged in various domains by six-months’ age for all Study 3 participants. Communication abilities were relatively spared at this age. Developmental delays persisted among all participants at 12 months but occurred in different areas than in the six-months assessment. Increased communication delays were evident at 12 months. Research strengths included investigating different HIE severity grades and describing evolving swallowing, feeding and developmental profiles over time. Conclusion: A deeper understanding of South African infants with HIE was obtained. The importance of early SLT involvement in mitigating infants’ swallowing, feeding, and communication difficulties was highlighted. The need for dynamic assessment was established. A continuous route of early intervention is proposed, from birth to school-going age.