Gastric aspirates were sampled for bleeding and pH, and medication doses were doubled for failure of pH control, defined as two successive aspirates with pH less than 4.

• 胃液样本皆进行出血及酸碱度检查，若连续两次胃液酸碱度低于4，则表示酸碱值失去控制，此时，加倍药物剂量。