Efek suplementasi ekstrak ophiocephalus striatus terhadap luas penampang otot rektus femoris, otot bisep brakii, kadar prealbumin dan imbang nitrogen pasien sakit kritis dengan ventilator = Effect of ophiocephalus striatus extract supplementation on cross-sectional area of rectus femoris and biceps brachii, prealbumin levels, and nitrogen balance in critically ill patients with ventilator