Impact of Propofol Sedation upon Caloric Overfeeding and Protein Inadequacy in Critically Ill Patients Receiving Nutrition Support

Propofol, a commonly used sedative in the intensive care unit, is formulated in a 10% lipid emulsion that contributes 1.1 kcals per mL. As a result, propofol can significantly contribute to caloric intake and can potentially result in complications of overfeeding for patients who receive concurrent enteral or parenteral nutrition therapy. In order to avoid potential overfeeding, some clinicians have empirically decreased the infusion rate of the nutrition therapy, which also may have detrimental effects since protein intake may be inadequate. The purpose of this review is to examine the current literature regarding these issues and provide some practical suggestions on how to restrict caloric intake to avoid overfeeding and simultaneously enhance protein intake for patients who receive either parenteral or enteral nutrition for those patients receiving concurrent propofol therapy.

Relationship Between Triglyceride Tolerance, Body Mass Index, and Fat Depots in Hospitalized Patients Receiving Parenteral Nutrition

BACKGROUND

Hypertriglyceridemia has been associated with adverse outcomes in patients receiving intravenous fat emulsions (IVFEs), but little is known about its prevalence and causes.

MATERIALS AND METHODS

The study investigated whether a relationship exists between body mass index (BMI) and triglyceride tolerance in parenterally fed patients. We conducted a retrospective analysis of 287 adults receiving parenteral nutrition to determine whether patients with very low BMI (VLBMI, <16 kg/m(2)) tolerate IVFEs better than do patients with low BMI (LBMI, 16-18.4 kg/m(2)), normal-weight patients (NBMI, 18.5-24.9 kg/m(2)), and overweight/obese patients (HBMI, ≥25 kg/m(2)).

RESULTS

The median triglyceride concentration during IVFE was significantly lower in VLBMI patients at 107 mg/dL compared with 124 mg/dL in non-VLBMI patients (P = .016), despite higher lipid infusion rates in the VLBMI group. There was a significant association between triglycerides and BMI in the aggregate cohort (R = 0.2375, P < .0001), with the highest frequency of hypertriglyceridemia occurring in HBMI patients despite relatively lower lipid and energy supply. In a subset of VLBMI patients (n = 36) who had an abdominal computed tomography scan, there was 25- to 100-fold variability in the size of the abdominal adipose tissue depots. In this subgroup, triglyceride concentrations correlated with visceral fat but not subcutaneous abdominal fat.

CONCLUSIONS

In summary, patients with VLBMI have lower triglyceride concentrations during IVFEs than do other individuals, but there is considerable variability in triglycerides and body fat in this group. Caution should be employed with the use of IVFEs, especially in HBMI patients.

Triacylglycerol-rich lipoprotein margination: a potential surrogate for whole-body lipoprotein lipase activity and effects of eicosapentaenoic and docosahexaenoic acids

BACKGROUND

Margination occurs when blood borne particles attach to the vessel wall. Triacylglycerol-rich lipoprotein (TRL) particles marginate when they bind to endothelial lipoprotein lipase (LpL).

OBJECTIVE

This study was undertaken to determine whether TRL margination reflects in vivo LpL activity and whether n-3 fatty acids affect fasting and fed TRL margination.

DESIGN

Healthy subjects (n = 33) began with a 4-wk, placebo (olive oil; 4 g/d) run-in period and were then randomly assigned to 4 wk of treatment with 4 g/d of ethyl esters of either safflower oil (SAF; control), eicosapentaenoic acid (EPA), or docosahexaenoic acid (DHA). Margination volume (MV) was calculated by subtracting true from apparent plasma volume.

RESULTS

MVs were 3 times as great during the fasting state as during the fed state (P < 0.0001). In both the fasting and the fed states, MV was significantly correlated with plasma triacylglycerol and TRL half-lives. In the fed state, MV was also correlated with preheparin LpL, whereas in the fasting state it was not. There was no significant correlation between preheparin LpL and postheparin LpL in the fasting state. Relative to SAF, EPA and DHA supplementation resulted in higher MVs by 64% and 53% (both P < 0.001), respectively, in the fasting state, without significantly reducing fasting triacylglycerol concentrations. In the fed state, DHA doubled the MV (P < 0.05), whereas EPA had no significant effect.

CONCLUSIONS

The correlations between MV and TRL half-lives and preheparin LpL suggest that MV could be a reflection of whole-body LpL binding capacity. The increases in MVs with EPA and DHA supplementation suggest that these fatty acids may increase the amount of endothelial-bound LpL or its affinity for TRL.

The importance of clinical factors in parenteral nutrition-associated hypertriglyceridemia

AIMS

The purpose of this study was to establish the relevance of several clinical factors associated with parenteral nutrition (PN) hypertriglyceridemia and to construct a predictive model for this complication.

METHOD

This multicenter study included all patients with initial serum triglyceridemia <3 mmol and receiving a minimum of 7 days' PN therapy. The study ended for each patient when hypertriglyceridemia developed or PN was terminated. Two multivariate models were constructed, one to study the clinical factors and the second to predict plasma triglyceridemia. A total of 22 clinical factors studied as independent variables were included in the multiple-step regression models only when they showed a P-value over 0.1. Statistical significance was determined by the confidence interval of the odds ratio (OR) and the partial regression coefficient (b).

RESULTS

The study included 260 patients from 14 hospitals. Lipid administration was 0.83+/-0.37 g/kg/day. Among the total, 68 patients (26.2%) showed hypertriglyceridemia. Variables included in both models were serum glucose (OR, 2.63; b, 0.06), renal failure (OR, 10.56; b, 1.70), corticoid administration >0.5 mg/kg (OR, 7.98; b, 0.97), pancreatitis (OR, 4.38; b, 0.64), sepsis (OR, 4.48; b, 0.24), lipids infused (OR, 3.03; b, 0.24) and heparin administration >3 mg/kg/day (OR, 0.11; b, -1.21).

CONCLUSION

Although the rate of lipid infusion was low, certain clinical factors modified triglyceridemia. Nevertheless, relatively fast plasma clearance of lipids infused indicates that a reduction in lipid supply could be a quick, effective measure for controlling hypertriglyceridemia. Thus, careful monitoring of patients with clinical factors predicting risk in the model studied, with adjustment of lipid perfusion rates accordingly, is suggested to avoid hypertriglyceridemia.