[Rules for taking medicines].

Using the infusion of D-(-)-3-hydroxy-[1,2,3,4,-13C4]butyrate at tracer doses, we measured total ketone body turnover in 13 premature and 10 at term infants in the first 2 weeks after birth. The premature infants received parenteral and/or oral feeding. The normal newborns were either recently fed or briefly fasting. The premature and the fed at term infants had comparable concentrations of ketone body (476 +/- 86 and 406 +/- 78 mumol/l) and free fatty acids (FFA) (309 +/- 47 and 325 +/- 75 mumol/l). In the premature newborns, ketone body turnover rates (3.2 +/- 0.2 mumol kg-1 min-1) were 74% that of fed newborns at term (4.3 +/- 0.3 mumol kg-1 min-1, p < 0.05), and 18% that of normal newborns during a brief fast (17.3 +/- 1.3 mumol kg-1 min-1, p < 0.01). Ketone body production rates correlated with plasma FFA concentrations in both groups (r = 0.62 and 0.69, p < 0.05). However, for a similar plasma FFA content, ketone production was 2- to 3-fold lower in the premature, indicating an immature hepatic capacity to convert FFA into ketones. Our study therefore shows that ketogenesis is already active in infants born 10 weeks before normal term and continuously fed, but that daily ketone production is lower than at term.

Fasting↗

PubMed1995

[The recent trend in preoperative fasting].

It has been generally practiced that patients are restrained from any foods and water 4-6 hr prior to anesthesia. Recent trends of anesthesiologist, however, are to permit the patients to take fluid until 2-3 hr before inducing anesthesia, as described in the guidelines from Canadian Anaesthetists' Society in 1990, and in the authoritative textbooks of anesthesia. We compared effects of the preoperative fasting between age-matched groups of patients constrained to: 1) 6 hr absolute preoperative fasting, and 2) 6 hr fasting but free for taking clear fluid until 2 hr before operation. Residual gastric volume and pH immediately after inducing anesthesia were monitored. In the respective age groups from infant to the aged, no significant changes were observed between 1) and 2). Considering that light meal leaves the stomach in 1.5-3 hr and clear fluid almost immediately, these results accurately explain and support relevance of the current concept concerning the preoperative fasting. Furthermore, since actual incidence of aspiration pneumonia during anesthesia is sufficiently low, strict preoperative fasting may be unreasonable. We consider that reducing the fasting time may not increase the risk of pulmonary aspiration and recommend our practical method consisting of preoperative 6 hr withholding solid foods while allowing clear fluid ingestion until 2-3 hr before inducing anesthesia.

Fasting↗