Selective gut decontamination reduces nosocomial infections and length of stay but not mortality or organ failure in surgical intensive care unit patients.

Suppression of the gut luminal aerobic flora to reduce nosocomial infections was tested in a prospective, randomized, double-blind, placebo-controlled clinical trial in patients in a surgical intensive care unit who had persistent hypermetabolism. Forty-six patients were randomized to receive either norfloxacin, 500-mg suspension every 8 hours, together with nystatin, 1 million units every 6 hours, or matching placebo solutions administered through a nasogastric tube within 48 hours of surgical intensive care unit admission. Selective gut decontamination with the experimental therapy or placebo solutions continued for at least 5 days or until the time of surgical intensive care unit discharge. Patients were monitored with routine surveillance cultures for the development of nosocomial infections, as defined by criteria from the Centers for Disease Control. All other therapy was given as clinically indicated, including systemic antibiotics. The selective gut decontamination group experienced a significant reduction in the incidence of nosocomial infections and a reduced length of stay. However, these results were not associated with a concomitant decrease in progressive multiple organ failure syndrome, adult respiratory distress syndrome, or mortality.

Quality of care concepts and nutrition support.

The Joint Commission on Accreditation of Healthcare Organizations' (JCAHO) Agenda for Change has refocused and redefined quality monitoring in health care. The JCAHO has operationalized these new concepts of quality monitoring and evaluation by means of a 10-step process that includes the development of clinical indicators. Theoretical frameworks for the 10-step process were drawn from the work of theorists whose applications of quality-monitoring methods occurred in business and industry. An enhanced understanding of the current JCAHO definitions of quality and processes for quality measurement will help practitioners prepare for future accreditation surveys. A review of quality monitoring and evaluation activities in nutrition support has demonstrated a need for more published accounts to document these important activities.

Urinary urea nitrogen: too insensitive for calculating nitrogen balance studies in surgical clinical nutrition.

Urinary urea nitrogen (UUN) has been used as an estimate of total urinary nitrogen (TUN) when calculating nitrogen output for nitrogen balance (NB) studies. UUN is assumed to constitute 80 to 90% of the total nitrogen output; when estimating TUN from UUN, UUN values are multiplied by 1.25 to correct for non-urea nitrogen components. In order to evaluate the validity of estimating total urinary nitrogen output from measured UUN in a clinical setting, 491 UUN:TUN paired studies were performed on 24-hour urine collections in general surgical/trauma patients who had measured TUN outputs ranging from 0.04 to 54.0 g/d. Assessment of 315 NB studies was done to compare NB values of those calculated by using UUN as an estimate of TUN with those calculated from measured TUN. Patients in both studies were subdivided into four stress categories, using TUN/day as the index: less than 5 g, 5-10 g, 10-15 g, and greater than 15 g. On average, 80 to 90% of TUN is represented by the UUN. However, in our patient population the variability ranged from 12 to 112%. If these UUN values are used as estimates for TUN in calculating NB, variations of up to 12 g/d would result. Application of the correction factor of 1.25 is not consistent in correcting for nonurea nitrogen components in this clinical setting. The use of actual rather than estimated TUN may be a more accurate and appropriate method than UUN when calculating NB.

Growth hormone enables effective nutrition by peripheral vein in postoperative patients: a pilot study.

The purpose of this pilot study was to investigate the metabolic effects of growth hormone (GH) (Humatrope, Eli Lilly & Co., Indianapolis, IN) administration in postoperative (PO) patients receiving peripheral vein nutrition. Seven, well-nourished, nondiabetic patients undergoing elective surgical procedures were given either no drug (n = 3), GH 30 micrograms/kg/day (n = 2), or GH 60 micrograms/kg/day (n = 2) sub-Q daily until eating, up to 7 days PO. All the patients received 5% dextrose with electrolytes in the first 24 hours PO and then received calories at 80 +/- 5% of the measured resting energy expenditure (REE) and amino acid at 1 g/kg/day with electrolytes, vitamins, and minerals. There were no significant outcome differences between the 30 and 60 micrograms/kg/day groups and, therefore, these groups were analyzed together (n = 4). By day 6 of the study, the GH group had a significant reduction in the respiratory quotient (RQ) measured by indirect calorimetry; an increase in nitrogen retention; an increase in plasma transferrin concentrations; and an increase in plasma insulinlike growth factor (IGF1) concentration. There was no increase in blood glucose concentrations, or decrease in urinary 3-methylhistidine excretion; and no adverse effects occurred. We concluded that GH in PO patients on hypocaloric nutrition promoted protein synthesis, fat oxidation, and nitrogen retention. Effective parenteral nutritional support in postoperative adult patients can be achieved without the use of central vein access.

Enteral nutrition does not prevent multiple organ failure syndrome (MOFS) after sepsis.

Gut malnutrition in patients with persistent hypermetabolism is hypothesized to be an important factor in postseptic multiple organ failure syndrome (MOFS). The hypothesis was made that enteral nutrition (EN) started at the onset of hypermetabolism could reduce the incidence of MOFS. Sixty-six patients with persistent hypermetabolism 4 to 6 days after onset of sepsis were prospectively randomized to receive either parenteral nutrition (PN) or enteral nutrition (EN) at 1.5 gm protein/kg/day and 30 nonprotein calories/kg/day; the EN and TPN were of the same composition. There was no reduction in either the incidence of MOFS or mortality attributable to the route of nutrition administration. The PN group tended to have better visceral protein support; the EN group had more gut complications. When analyzed, the type of formula given did have an effect on the nutritional outcome but not on the mortality rate. A formula with a nonprotein-calorie-to-nitrogen ratio of 100:1 was associated with more nitrogen retention, higher levels of visceral proteins, and better gut tolerance. The route of nutrition administration does not seem to affect the incidence of postseptic MOFS or mortality when hypermetabolism is already present and when commercially available nutritional formulas are used. The relationships among the route of nutrition, the type of enteral formula, and the disease process of hypermetabolism and MOFS appear to be complex and require much more investigation before the role of the gut and enteral nutrition can be defined.

Enteral feeding in sepsis: a prospective, randomized, double-blind trial.

In an attempt to meet better the needs of patients with hypermetabolic stress, amino acid formulas have been modified (MAA). As part of a total parenteral nutrition regimen, MAA have been associated with improvement in parameters of nutrition and survival. The safety and efficacy of these formulas in balanced enteral nutrition was assessed in malnourished patients with moderate to high levels of stress undergoing surgery. The nutritional targets were 5 gm/kg/day glucose, 0.8 gm/kg/day fat, and 0.27 gm/kg/day amino acid nitrogen. In an initial nine studies, the MAA nutrition was safe even in the presence of ileus. A double-blind, randomized, prospective trial was then undertaken in 18 patients in an isocaloric, isonitrogenous design with the nitrogen source as MAA (44% branched-chain amino acids) or standard amino acids (28% branched-chain amino acids). The patients receiving MAA had enhanced nitrogen retention, visceral protein mass, and indices of survival.