Intermittent and Bolus Methods of Feeding in Critical Care

Abstract

Enteral nutrition (EN) can be administered using various methods such as continuous, cyclic, intermittent, and bolus techniques, either alone or in combination. In continuous feeding, an hourly rate of EN is administered using a feeding pump over 24 h. In cyclic feeding, EN is administered via a feeding pump in less than a 24-h time period. In intermittent feeding, EN is administered over 20-60 min every 4-6 h with or without a feeding pump. In bolus feeding, EN is administered via a syringe or gravity drip over a 4-10-min period. A number of factors are taken into consideration when selecting EN delivery modalities, such as the medical condition of the patient, expected tolerance to tube feeding, location of the feeding tube tip, type of formula used, nutritional requirements, mobility of the patient, availability of electric feeding pump, and cost. However, too little data are available at present to make a strong recommendation for one particular method of enteral feeding over others. In practice, it is generally considered acceptable for pump-assisted continuous feeding in critically ill patients to be initiated at a rate of 10-20 ml/h and then gradually increased to the target rate. For medically stable patients, intermittent and bolus feeding methods are preferred due to practical issues, such as patient mobility, convenience, and cost. At present, no evidence is available regarding the optimum feeding modality for not only an ordinary clinical setting but also critical care setting.