HISTOCHEMICAL AND ULTRASTRUCTURAL-STUDY OF SKELETAL-MUSCLE IN PATIENTS WITH SEPSIS AND MULTIPLE ORGAN FAILURE SYNDROME (MOFS)

Muscle biopsies for histochemical and ultrastuctural analysis were obt ained from seven critically ill patients admitted to the Intensive Car e Unit of the ''Domingo Luciani'' Hospital, Caracas, Venezuela. The sa mple included two patients with sepsis of abdominal origin, and five t hat presented sepsis/MOFS, with renal, hepatic, and respiratory distur bances and muscular weakness. Sections were examined for myosin adenos ine triphosphatase (ATPase) after pre-incubation with both acid buffer (pH 4.37 and 4.6) and alkaline buffer (pH 10.3), for reduced nicotina mide dinucleotide diaphorase (NADHd), and for alpha-glycerophosphate d ehydrogenase (alpha-GPDH). Sections were stained with hematoxilin and eosin to look for pathological changes and examined with a transmissio n electron microscope. Skeletal muscle of patients in early stage of s epsis showed a normal aspect with light microscopy, but at the ultrast ructural level some of the fibres showed atrophy and some capillaries looked altered. Patients with sepsis/MOFS exhibited an evident muscle disorder with oedema, infiltrate, atrophy and segmental necrosis. All fibre types showed decrease in diameter; specially fibre types IIA and IIB. Intramuscular capillaries were thickened and occluded, indexes o f capillarity were slightly reduced, and fibre oxidative activity was decreased. At ultrastructural level fibres showed severe atrophy, cont ractile system disorganization and segmental necrosis. Capillaries wer e also altered and the mononuclear cell infiltrate was abundant and re presented by macrophages, lymphocytes and mastocytes.