This Is A Question For My Mother. She Is Diebetic,

This is a question for my mother. She is diebetic, and currently going through chemo for uterine cancer. She taxes 10mg oxycontin for pain, insulin for diabetes, and is currently on 40mg of Lasix due to recent water retention. Over the past few days she had become very weak. Needs help in and our if bed, toileting, etc. She took her Lasix tosay and has drank at least 6 32oz glasses of tea...no water...and she has only voided 2x since 8 am this morning...4/30/16. Is an ER trip in order?? I am a CNA and from past experience, it sounds as if she may be having some kidney or bladder trouble.