An Investigation of The Relationship Between Muscle Mass, Physiological Parameters, and Blood Gas Levels in Adult Patients Hospitalized in The Intensive Care Unit

Inclusion Criteria: * Inclusion Criteria: Age: Adult patients aged 18 years and older Clinical unit: Patients admitted to palliative care, pulmonary intensive care, or cardiovascular intensive care units Length of stay: Patients expected to remain in the intensive care unit for at least 48 hours Physical eligibility: Patients with no conditions preventing the measurement of muscle mass Clinical stability: Patients without severe hemodynamic instability or active bleeding at the time of measurement Ethical compliance: Individuals who have volunteered to participate in the study and whose informed consent has been obtained from them or their legal representative Exclusion Criteria: * Exclusion Criteria: * Patients with a history of previously diagnosed neuromuscular disorders (myasthenia gravis, Guillain-Barré syndrome, chronic polyneuropathies) * Patients with severe renal or hepatic insufficiency that could directly affect muscle mass * Presence of severe edema: Patients with a pitting edema score of 3+ or 4+ on the pitting edema test, or individuals with documented widespread edema in nursing or medical records * Patients with an amputation, hematoma, or open wound on the extremity to be measured * Pregnant patients * Patients whose intensive care stay lasted less than 48 hours or for whom the measurement could not be completed due to discharge or death