There is considerable current interest in fat emulsions for intravenous use because of the need for a parenteral fluid rich in calories but low in osmotic effect. Fat yields 9 Cal. per gram when metabolized as compared with 4 Cal. from protein or carbohydrate, thus allowing a significant caloric intake without excess water loading. Also, fat may be administered in a higher concentration than protein or carbohydrate since it causes less venous irritation and does not spill in the urine.
The requirements for a fat emulsion for routine clinical use are shown in the Table.
Although none of the presently available emulsions fully meets all the above requirements, very encouraging progress has been made. Major contributions have been made by Yamakawa,1 who in 1920 reported a successful artificial fat emulsion; by Holt, Tidwell, and Scott,2 who extensively tested an emulsion in undernourished children in 1935, and, more recently,