Melissa Pleva

Critical Illness, Gastrointestinal Complications, and Medication Therapy during Enteral Feeding in Critically Ill Adult Patients

Critically ill patients who are subjected to high stress or with severe injury can rapidly break down their body protein and energy stores. Unless adequate nutrition is provided, malnutrition and protein wasting may occur, which can negatively affect patient outcome. Enteral nutrition (EN) is the mainstay of nutrition support therapy in patients with a functional gastrointestinal (GI) tract who cannot take adequate oral nutrition. EN in critically ill patients provides the benefits of maintaining gut functionality, integrity, and immunity as well as decreasing infectious complications. However, the ability to provide timely and adequate EN to critically ill patients is often hindered by GI motility disorders and complications associated with EN. This paper reviews the GI complications and intolerances associated with EN in critically ill patients and provides recommendations for their prevention and treatment. It also addresses the role of commonly used medications in the intensive care unit and their impact on GI motility and EN delivery.

Hyperglycemic Events in Non–Intensive Care Unit Patients Receiving Parenteral Nutrition

BACKGROUND Evidence supports the benefits of tight glycemic control in many patient populations. There is no consensus on appropriate targets for blood glucose (BG) values in patients receiving parenteral nutrition (PN). Characterization of the frequency of BG abnormalities is necessary to identify effective strategies to improve glycemic control in this patient population. METHODS Data were retrospectively collected over a 2-month period from 50 non-intensive care unit (ICU) patients who received PN. Frequencies of abnormal BG (defined as BG outside the range of 2 criteria: 80-200 mg/dL and 100-150 mg/dL) were determined. An event of hyperglycemia was defined as the 48-hour period following a BG value outside of 80-200 mg/dL. Each event was evaluated for resolution within 48 hours of the triggering BG value. RESULTS Hyperglycemia (at least 1 BG value >200 mg/dL) occurred in 22 patients (44%). Of the 1738 BG values measured, 8.7% were >200 mg/dL, resulting in 1.4 events of hyperglycemia per patient. The average blood glucose value for the population was 140 mg/dL. The frequency of hyperglycemia and hypoglycemia increased substantially, with only 1 patient having a PN course with normoglycemia using the 100-150 mg/dL criterion. CONCLUSION The frequency of hyperglycemia in non-ICU PN patients is high according to either evaluation criterion. A method is described for using events to characterize hyperglycemia, which may be more useful than traditional methods in clinical decision making and identification of need for process improvements. These data suggest the need to develop better methods for BG control in non-ICU PN patients.

Pharmacokinetics of Ertapenem in Critically Ill Patients Receiving Continuous Venovenous Hemodialysis or Hemodiafiltration

ABSTRACT This study characterizes the pharmacokinetics of ertapenem, a carbapenem antibiotic, in critically ill adult subjects receiving continuous renal replacement therapy (CRRT). Eight critically ill patients with suspected/known Gram-negative infections receiving continuous venovenous hemodialysis (CVVHD) or continuous venovenous hemodiafiltration (CVVHDF) and ertapenem were enrolled. One gram of ertapenem was infused over 30 min. Predialyzer blood samples were drawn with the first dose of ertapenem from the hemodialysis tubing at time zero, 30 min, and 1, 2, 4, 8, 12, 18, and 24 h after the start of the ertapenem infusion. Effluent was collected at the same time points. Ertapenem total serum, unbound serum, and effluent concentrations from all eight subjects were used simultaneously to perform a population compartmental pharmacokinetic modeling procedure using NONMEM. Monte Carlo simulations were performed to evaluate the ability of several ertapenem dosing regimens (500 mg once daily, 750 mg once daily, 500 mg twice daily, and 1,000 mg once daily) to obtain effective unbound serum concentrations above 0.5, 1, and 2 μg/ml. For our simulated patients, all regimens produced unbound ertapenem concentrations above 2 μg/ml for 40% of the dosing interval for at least 96% of simulated patients. (This study has been registered at ClinicalTrials.gov under registration no. NCT00877370.)

Pharmacokinetics of Oseltamivir and Oseltamivir Carboxylate in Critically Ill Patients Receiving Continuous Venovenous Hemodialysis and/or Extracorporeal Membrane Oxygenation

To investigate oseltamivir and oseltamivir carboxylate pharmacokinetics in critically ill patients who were receiving continuous venovenous hemodialysis (CVVHD) and/or extracorporeal membrane oxygenation (ECMO).

Albumin Use Guidelines and Outcome in a Surgical Intensive Care Unit

HYPOTHESIS Restrictive albumin use guidelines in the surgical intensive care unit (SICU) will not increase mortality and will result in cost savings. DESIGN Prospective cohort study. SETTING Tertiary teaching hospital. PATIENTS All patients admitted to the SICU from July 1, 2004, through July 1, 2005, were included in this study. INTERVENTIONS Patients in the first 3 quarters of the study were treated with no restriction on albumin use. An organized educational program was initiated by the new intensivist-led critical care team and directed toward the residents, nursing staff, and primary surgical teams. Appropriate albumin use guidelines were instituted in the last quarter. MAIN OUTCOME MEASURES Prospective clinical and outcome data were collected. Albumin use data and costs were obtained from the pharmacy prospective database. RESULTS A total of 1361 patients were included in the study. A statistically significant reduction in albumin use (54%) was found in the fourth quarter (P = .004), and a substantial cost saving was realized (56% reduction in cost) with the albumin use guidelines. Restrictive use of albumin had no negative impact on ICU mortality. Mean Acute Physiology and Chronic Health Evaluation III scores on ICU day 1 were not different. No significant difference in mean ICU length of stay was noted. Maintained reduction in the use of albumin was documented during the next 6 quarters. CONCLUSIONS The implementation of albumin use guidelines during critical care resuscitation using an educational approach in a SICU is associated with reduced albumin use, significant cost savings, and no negative impact on ICU outcome. Continued educational efforts promoting evidence-based practices in the ICU are warranted.

Nutrition Therapy for ALI and ARDS

The importance of nutrition support in critically ill patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) cannot be overstated. ALI and ARDS are characterized by a proinflammatory response associated with hypercatabolism that could lead to significant nutrition deficits. Nutrition support is necessary to prevent cumulative caloric deficits, malnutrition, loss of lean body mass, and deterioration of respiratory muscle strength. Furthermore, early delivery of enteral nutrition has been associated with the modulation of stress and the systemic immune response as well as the attenuation of disease severity.

Role of unit-specific combination antibiograms for improving the selection of appropriate empiric therapy for gram-negative pneumonia.

In an effort to improve the selection of appropriate empiric gram-negative therapy for pneumonia, we examined intensive care unit-specific combination antibiograms. These antibiograms were able to predict appropriate empiric gram-negative therapy. Empiric combination therapy based on unit-specific combination antibiograms may aid in the selection of therapy for gram-negative pneumonia.

Are Predictive Energy Expenditure Equations in Ventilated Surgery Patients Accurate

Background: While indirect calorimetry (IC) is the gold standard used to calculate specific calorie needs in the critically ill, predictive equations are frequently utilized at many institutions for various reasons. Prior studies suggest these equations frequently misjudge actual resting energy expenditure (REE) in medical and mixed intensive care unit (ICU) patients; however, their utility for surgical ICU (SICU) patients has not been fully evaluated. Therefore, the objective of this study was to compare the REE measured by IC with REE calculated using specific calorie goals or predictive equations for nutritional support in ventilated adult SICU patients. Materials and Methods: A retrospective review of prospectively collected data was performed on all adults (n = 419, 18-91 years) mechanically ventilated for >24 hours, with an Fio 2 ≤ 60%, who met IC screening criteria. Caloric needs were estimated using Harris-Benedict equations (HBEs), and 20, 25, and 30 kcal/kg/d with actual (ABW), adjusted (ADJ), and ideal body (IBW) weights. The REE was measured using IC. Results: The estimated REE was considered accurate when within ±10% of the measured REE by IC. The HBE, 20, 25, and 30 kcal/kg/d estimates of REE were found to be inaccurate regardless of age, gender, or weight. The HBE and 20 kcal/kg/d underestimated REE, while 25 and 30 kcal/kg/d overestimated REE. Of the methods studied, those found to most often accurately estimate REE were the HBE using ABW, which was accurate 35% of the time, and 25 kcal/kg/d ADJ, which was accurate 34% of the time. This difference was not statistically significant. Conclusion: Using HBE, 20, 25, or 30 kcal/kg/d to estimate daily caloric requirements in critically ill surgical patients is inaccurate compared to REE measured by IC. In SICU patients with nutrition requirements essential to recovery, IC measurement should be performed to guide clinicians in determining goal caloric requirements.

Impact of an intravenous magnesium shortage on potassium doses in adult surgical patients receiving parenteral nutrition

BACKGROUND Shortages of parenteral nutrition (PN) components have been common in recent years. Effects on patient management and outcomes have not been well documented. This study aimed to determine the effect of a parenteral magnesium shortage, and an institutional decision to omit magnesium from adult PN, on magnesium and potassium doses and serum concentrations. MATERIALS AND METHODS This was a retrospective cohort study of adult surgical patients during two 6-month periods: prior to the magnesium shortage (2011) and during the shortage (2012). The relation between study period and electrolyte doses was evaluated by unadjusted and adjusted mixed models, while the relation between study period and hypokalemia and hypomagnesemia exposure was evaluated by Students t tests and multiple linear regression. RESULTS During the shortage, patients received more supplemental magnesium (0.11-0.12 mEq/kg/d, P < .0001) but received less total daily magnesium (0.08-0.09 mEq/kg/d, P < .0001) and had greater exposure to hypomagnesemia (9.6-14.2 h·mcg/dL/h, P < .05 for all comparisons except multivariate analysis in a matched subpopulation). Patients received similar amounts of potassium in PN (0.06-0.08 mEq/kg/d less, P < .05 for full cohort but P > .05 for matched cohort), in supplemental doses (0.01-0.05 mEq/kg/d less, P > .05), and in total (0.07-0.14 mEq/kg/d less, P > .05), and they had similar exposure to hypokalemia. CONCLUSION Daily magnesium doses were lower and hypomagnesemia exposure was greater during the shortage, but the differences were numerically small and their clinical significance was questionable. Potassium doses and hypokalemia exposure were not higher during the shortage. This supports the strategy of omitting magnesium from PN of select patients and supplementing as clinically necessary.