Intralipid Administration Research Articles

Intralipid Effects on Preterm Neonate Serum

SummaryThe effects of Intralipid (IL) administration of preterm infants have been investigated. For this purpose, adult neutrophils were stimulated by infant sera collected before and after IL treatment. A definite decrease (p < 0.0005) in chemoattractant capacity of zymosan‐activated serum was observed after IL. On the other hand, no difference in the opsinizing abilities of untreated versus treated sera could be demonstrated by measuring the chemiluminescence responses to serum‐opsonized zymosan. This study emphasized the need of caution in the use of IL treatment for preterm infants.

Intralipid effects on preterm neonate serum: chemoattractant and opsonizing capacities.

The effects of Intralipid (IL) administration of preterm infants have been investigated. For this purpose, adult neutrophils were stimulated by infant sera collected before and after IL treatment. A definite decrease (p less than 0.0005) in chemoattractant capacity of zymosan-activated serum was observed after IL. On the other hand, no difference in the opsinizing abilities of untreated versus treated sera could be demonstrated by measuring the chemiluminescence responses to serum-opsonized zymosan. This study emphasized the need of caution in the use of IL treatment for preterm infants.

Intralipid administration induces a lipoprotein lipase-like activity in the livers of starved adult rats.

The administration of Intralipid to starved adult rats induces the appearance of lipoprotein lipase (LPL)-like activity in the liver, whereas the so-called hepatic triacylglycerol lipase is unaffected. This LPL-like activity is eluted by 1.5 M-NaCl from heparin-Sepharose columns. This partially purified fraction is inhibited by 1.0 M-NaCl (91%) and by 1.0 mg of protamine sulphate/ml (79%), whereas it is stimulated 69-fold by the presence of 8.0 micrograms of apolipoprotein C-II/ml and inhibited by anti-LPL antibodies. We conclude that Intralipid administration induces the appearance of LPL activity in livers of starved adult rats. Its possible origin is discussed.

Effect of intralipid on the neonatal pulmonary bed: An echographic study

The effect of Intralipid infusion on pulmonary vascular resistance was studied prospectively by serial echocardiography on 13 occasions in six low birth weight infants. After 90 minutes of Intralipid infusion, the ratio of right ventricular preejection period to ejection time (RVPEP/ET) rose from 0.232 +/- 0.025 (mean +/- SD) to 0.285 +/- 0.035 (P = 0.0001). Of the 13 infusions studied, six (43%) resulted in RVPEP/ET values suggestive of pulmonary hypertension. Six LBW infants were observed over the same time period without Intralipid infusion, and RVPEP/ET did not change (0.209 +/- 0.035 vs 0.194 +/- 0.024). The increase in RVPEP/ET with Intralipid administration could not be explained by differences in preload or contractility, and most likely reflects an increase in pulmonary vascular tone. Caution in the use of Intralipid is recommended in infants who would be at particular risk from increased pulmonary vascular resistance.

Increased In Vitro and In Vivo Generation of Procoagulant Activity (Tissue Factor) by Mononuclear Phagocytes After Intralipid Infusion in Rabbits

Intralipid, a fat emulsion widely used in parenteral nutrition, can produce marked functional changes of the mononuclear phagocyte system. We investigated the effect of Intralipid administration on the generation of procoagulant activity by rabbit mononuclear phagocytes. Two groups of ten rabbits given either a single infusion of Intralipid 10% or a similar volume of sterile saline were studied before and after infusion. Procoagulant activity was measured on isolated blood mononuclear cells after incubation with and without endotoxin, using a one-stage clotting assay. Cells from animals infused with Intralipid produced significantly more procoagulant activity than controls (P less than .01). Results were similar when freshly collected whole blood was incubated with and without endotoxin, and procoagulant activity was measured on subsequently isolated mononuclear cells (P less than .01). In addition, when rabbits were given a single injection of endotoxin, blood and spleen mononuclear cells harvested 50 to 60 minutes after the injection from animals pretreated with Intralipid expressed five to seven times more procoagulant activity than did cells from animals pretreated with saline. In all instances, procoagulant activity was identified as tissue factor. These findings suggest that Intralipid may cause functional changes in mononuclear phagocytes, resulting in increased production of tissue factor on incubation in short-term culture in vitro and in response to endotoxin in vivo.

Normal macrophage function in infants receiving intralipid by low-dose intermittent administration

The effect of soybean oil emulsion (Intralipid) therapy on serum complement levels was determined in infants who received Intralipid therapeutically (1 gm/kg over 12 hours, every other day). The effect of Intralipid on macrophage priming for increased superoxide anion production was studied in a mouse model. Intralipid administration did not affect either macrophage function. Serum levels of C2 and C4, complement components synthesized and secreted exclusively in macrophages, were not decreased either during the week the infants received Intralipid or in the week following administration. Macrophages from mice that had received Intralipid produced similar amounts of superoxide anion, as did macrophages from mice that had received saline solution. Our data suggest that macrophages in infants receiving Intralipid in this regimen will function normally.

Plasma activities of lipoprotein lipase, hepatic lipase and lecithin: cholesterol acyltransferase in patients considered for parenteral nutrition with fat emulsion

Intralipid is a fat emulsion which is widely used for intravenous nutrition in very ill patients. In order to know more about the capacity of these patients to metabolize exogenous triglycerides, the plasma activities of lipoprotein lipase (LPL), hepatic lipase (HL) and lecithin: cholesterol acyltransferase (LCAT), the key enzymes in the metabolism of serum lipoproteins were measured by a radioisotope technique in 23 critically ill patients and 20 patients with recent major surgery. Compared with normal volunteers, the activities were significantly decreased. On the other hand, the capacity to clear intravenously given Intralipid (0.1 g/kg), expressed as fractional removal rate (K2), was retained in patients. It is suggested that the measurement of K2 could not be useful to evaluate the capacity of Intralipid administration to satisfy the metabolic needs and also that its utilization must be reevaluated in terms of potential harmful effects.

979 EXPERIMENTAL EFFECTS OF INTRALIPID ON PULMONARY GAS EXCHANGE IN A LUNG-DAMAGED MODEL

Intralipid (IL) infusion in healthy adults has resulted in decreased pulmonary diffusing capacity (DLCO) and arterial(a) PO2. To assess the pulmonary effects of IL, 0.4 gm/kg of IL was infused over 1 hour into 9 adult rabbits whose lungs had been damaged by a prior infusion of 0.15 cc/kg of oleic acid. Triglyceride (TG) levels were significantly elevated at 1 hour and remained significantly above baseline despite Heparin infusion of 200 units/kg at 2 hours, 1 hour after IL infusion.There were no significant changes in pH, PaCO2 or alveolar(A)-arterial CO2 difference [P(A-a)CO2]. The PaO2 and P(a-A)O2 were significantly worse at peak TG levels but then progressively improved to baseline level or better despite only partial TG recovery. Although the immediate changes suggest that IL should not be administered to patients with lung disease, the subsequent TG-unrelated recovery indicates that chronic IL administration does not impair gas exchange. In fact, by an entirely different and as yet unexplained mechanism, pulmonary gas exchange may even be enhanced with chronic IL infusion.