| Popis: |
The safe and timely introduction of milk feeding is a fundamental part of neonatal care for preterm and low birth weight infants. Yet enteral feeding in such infants presents significant challenges for the neonatologist. Data from randomised controlled trials are sparse and there is limited evidence to guide clinical practice. Opinion about optimum feeding regimens varies considerably and this variation in opinion is likely to be reflected in similar variation in clinical practice. Different approaches to feeding appear to carry different risks and benefits and serious adverse clinical outcomes may accompany extremes of practice in this area. Much of the uncertainty around practice in enteral feeding has been engendered by inconsistent results from research studies. Most studies have centred upon necrotising enterocolitis (NEC), a serious and devastating bowel disease that primarily affects preterm infants. Mortality from NEC is high. The aetiology of the condition remains elusive and is likely to be multifactorial, but early and rapid enteral feeding has been implicated. In contrast, delayed feeding necessitating prolonged use of central venous catheters and parenteral nutrition may increase susceptibility of preterm infants to severe systemic infection. The potential role of enteral feeding in the development of NEC is of great interest because unlike many other factors, it is amenable to change. However, only through welldesigned trials of different practice will optimum strategies for feeding in high-risk infants begin to emerge. The design of acceptable and feasible clinical trials that fall within the known margins of safety is challenging. As studies of neonatal feeding practice would probably need to take place on an international basis to provide sufficient numbers of outcomes, disparities in practice between different countries may serve only to increase this challenge. An understanding of the variation in practice, the factors influencing this variation and the effects on feed-related outcomes is necessary to inform further research. There have been few recent detailed reports relating to opinions about feeding of preterm infants. No previous study has explored the relationship between available research evidence, clinician opinion and clinical practice. The subject of this thesis is a two-part observational study, conducted in the United Kingdom (UK) and Canada. A questionnaire survey sent to neonatal clinicians sought to investigate current opinion and reported practice with respect to enteral feeding of infants born at less than 30 weeks of gestation and/or 1501 g birth weight in the UK and Canada. This survey was complemented by a detailed retrospective review of the medical and nursing records of infants admitted to fifteen UK and three Canadian neonatal units. Opinions of neonatal clinicians were described and factors influencing feed-related decisions were explored. Analysis of infant feeding data allowed comparison and contrasting of different practices and exploration of short-term neonatal outcomes that may be related to or influenced by variation in practice. Questionnaire responses of 302 clinicians and feeding data from 670 infants were analysed. The results of the study confirmed wide variation both in opinion and in clinical practice across almost all aspects of enteral feeding. This was evident between and within neonatal units and between the two countries. Reported availability and clinicians' awareness of written guidelines to assist in decision-making were also extremely variable. The study demonstrated that a large number of factors appear to influence feeding practice, but that these, too, differ between countries. The most consistent influence affecting the advancement of enteral feeds was the presence of signs consistent with actual or suspected intra-abdominal pathology such as NEC. Occurrence of proven NEC and associated mortality were within previously reported ranges. The effects of variation on necrotising enterocolitis and other important clinical outcomes are not known. Important gaps in knowledge remain with respect to the rate of feed advancement and the relationship between therapeutic interventions and NEC. Further research is required and should be directed towards defining optimum feeding strategies that maximise benefits in terms of growth and neurodevelopment, whilst minimising morbidity and mortality associated with NEC and infection. |
