Initial Presentation

You are the F2 doctor in A&E in a busy hospital in central London. An 81 years old gentleman presented to you in a poor general condition and dilirium. From the limited data you could get at the moment, you know that he lives in a care home, suffers from depression and hasn't been eating and drinking very well the past week. His observations are fairly stable and he passes urine and not catheterised.  you requested urgent bloods and it came back after 30 minutes showing creatinine 670 umol/l ( N 70-100 umol/l) , urea of 20 mg/l  (N 2-7 mg/l) , Na 130 ( N 132-138 meq/l), and K 7.8 meq/l ( N 3.2-5.2 meq/l). His pH was 7.28 ( N 7.35-7.45 ), HCo3 18 ( N 22-26), Hb 107 ( N 112-116 ) and CRP was 182 ( N<8 ).

what's the next step of management?