None listed
Conditions
Brief summary
Critical ill patients treated in the ICU loose muscle mass at about 10% week. This is mainly due to a dramatic increase in muscle protein breakdown whereas muscle protein synthesis is, on average, normal. However this has only been measured in the early ICU treatment (up to 10 days) before. Since the loss of muscle mass sees to decrease when patients are treated for long periods (>10 days) the aim of this study is to measure skeletal muscle protein turnover between days 10-40 of ICU treatment. Skeletal muscle protein turnover is measured by infusing labelled amino acids (2H2-pheylalanine and 2H2-3-methylhistidine) and measuring their flux over the leg of patients. For this, following an 2 hours infusion of the amino acids, 3 samples from the femoral vein and a artery are taken with 5 minutes space; at the end a muscle biopsy is taken; and just before and after the sampling blood flow to the leg is measured using non invasive venous occlusion plethysmography. Samples are analyses for labelled and unlabelled amino acids and the protein kinetics are calculating using steady state 3 and 2 pool models. All details have been described before (Klaude et al, Clin Sci. 2007; 112:899-506). Patients will be measured when in the unit for 10 days or more. In some patients measurements will be repeated 8-12 days later, when possible. We hypothesize that the protein balance will be less negative with longer ICU stay.
Interventions
Skeletal muscle protein and amino acid kinetics will be measured in critically ill patients treated in the ICU for more then 10 days. Assessments are made 1-3 times 8-12 days apart in patients in the ICU between treatment day 10-40 after admission to the ICU.
Skeletal muscle protein and amino acid kinetics will be assessed measuring the fluxes of labelled and unlabelled amino acids over the leg of the patient. For this the patients receive an infusion of [2H5]phenylalanine (0.5 mg/kg/h) and [2
Skeletal muscle protein and amino acid kinetics will be measured in critically ill patients treated in the ICU for more then 10 days. Assessments are made 1-3 times 8-12 days apart in patients in the ICU between treatment day 10-40 after admission to the ICU. Skeletal muscle protein and amino acid kinetics will be assessed measuring the fluxes of labelled and unlabelled amino acids over the leg of the patient. For this the patients receive an infusion of [2H5]phenylalanine (0.5 mg/kg/h) and [2H2]3-methylhistidine (0.01 mg/kg/h) for 2.5 hours in a vein. After 2 hours and 15 minutes, 4 samples (5 minutes apart) will be taken simultaneously from an artery and the femoral vein. After 2 hours and 30 minutes a muscle biopsy is taken by a Bergstrom needle. Blood flow to the leg is measured with non-invasive venous occlusion plethysmography with 10 measurement at least 10 minutes before and 10 minutes after the sampling period. Steady state kinetics are used to assess muscle protein kinetics (protein synthesis, protein breakdown and protein balance) using the labelled amino acids. In addition amino acid fluxes are assessed by multiplying the arterial-venous difference of the amino acids times the plasma flow. If a patient that has been studied and is still in the ICU 8-12 days later, and this patient still meets the inclusion criteria and if research staff is available, the patient will be studied again. Patients will be studied for a maximum of 3 times. For every study the same protocol, as described above, is used.
Sponsors
Olav Rooyackers
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
An ICU stay of > 10 days after admission to the ICU. Patients are recruited and enrolled after day 10 in the ICU.
Exclusion criteria
Withhold of treatment, Contraindication to insertion of a catheter in the femoral vein and to a percutaneous muscle biopsy in the lateral portion the quadriceps femoralis muscle, No informed consent.
Outcome results
None listed