Overview
More and more patients survive a critical illness requiring admission to the intensive care unit, but they may be left with sequelae that are independent of the initial pathology. From a physical standpoint, the most visible complication is intensive care unit-acquired muscle weakness. A major factor in the development and persistence of muscle dysfunction appears to be the inflammatory response and the neuroendocrine stress response triggered by the initial critical insult. Persistence of inflammation beyond ICU discharge has been demonstrated in several studies. In response to inflammation, there is also increased oxidative stress associated with mitochondrial dysfunction.
The objectives of the present study are therefore:
to determine whether the broad inflammatory and metabolic profile of patients who have survived an ICU stay can predict the trajectory of muscle performance over the three months following ICU discharge; to compare this profile and muscle performance with those of non-critically ill surgical patients who have undergone a standardized inflammatory stress of lower intensity than that associated with critical illness; to investigate mitochondrial function in skeletal striated muscle after ICU stay, in light of the inflammatory and metabolic profile; to assess whether abnormalities in mitochondrial function also affect tissues other than skeletal muscle, in particular circulating blood mononuclear cells.
Eligibility
Inclusion Criteria
- Critical illness:
- anticipated ICU stay \>= 7 days
- Major abdominal surgery
- elective surgery
Exclusion Criteria:
- Active malignancy
- Inherited metabolic disorder
- Known muscle disease
- Pregnancy
- Patient refusal
- Patient unable to express informed consent (dementia, confusion)
- Known coagulation disorder (cirrhosis, genetic coagulopathy) or thrombocytopenia \< 100,000/mm³ on the day of biopsy, anemia with hemoglobin \< 9 g/dL on the day of biopsy, or treatment with anticoagulant agents (contraindication to muscle biopsies only)
- Pacemaker or other implanted electronic device (contraindication to bioelectrical impedance analysis only)
- Oxygen therapy (contraindication to indirect calorimetry during spontaneous ventilation)