RESPONSE OF SEVERELY MALNOURISHED PATIENTS TO PREOPERATIVE PARENTERAL-NUTRITION - A RANDOMIZED CLINICAL-TRIAL OF WATER AND SODIUM RESTRICTION

Preoperative parenteral nutrition (PPN) may be beneficial for severely malnourished patients who are candidates For a major elective surgica l procedure. The response to PPN, however, has not been thoroughly inv estigated. Expansion of the extracellular water compartment may occur in some patients, producing a further decrease in the serum albumin co ncentration and increasing the postoperative complications. Our aims w ere to investigate the occurrence of and factors associated with water and sodium retention during PPN and its impact on postoperative respi ratory complications. Forty-one patients with gastrointestinal cancer and severe malnutrition (weight loss >15% and/or serum albumin <35 g/L ) were randomly allocated to two groups receiving isocaloric isonitrog enous PPN for IO d. The Standard PPN Group (SG, n = 19) received 70% o f nonprotein calories as glucose, 45 cc of water . kg(-1). d(-1), and 140 mEq/d of sodium chloride; and the Modified Group (MG, n = 22) rece ived 70% of calories as fat, 30 cc of water . kg(-1). d(-1), and no so dium. Weight and albumin changes, diuresis, sodium and water balances, and postoperative complications were recorded. Ar, the end of PPN, th e SG showed a higher wright gain (0.8 versus -1.5 kg, P = 0.0001) and albumin decrease (-0.7 versus 2.3 g/L, P = 0.006), Diuresis and sodium balance were greater in the SG (1,230 versus 959 mL/d, P = 0.003 and 40 versus -27 mEq/d, P = 0.001). Weight changes correlated with water (r(2) = 0.46, P = 0.001) and sodium (r(2) = 0.62, P = 0.0001) balances . Inappropriate responses to PPN in both groups (expansion or depletio n of the extracellular water compartment) were associated with a signi ficant increase in pulmonary postoperative complications. During PPN, extracellular water expansion-as determined by increasing weight and l owering of the serum albumin concentration-and aggressive fluid therap y to treat water and sodium depletion seem crucial to the development of postoperative respiratory complications. (C) Elsevier Science Inc. 1997.