Confusion after tracheostomy

Hi my mums had a tracheostomy fitted on Wednesday due to the tumour pretty much blocking her airway, I saw her yesterday morning and she was very tired and complaining of “jelly legs” and general weakness, mums only getting 1500 calories currently in her RIG due to being at risk of re-feeding syndrome, the nurse said she’d speak to the dietician on Monday about potentially increasing her calories. However her text messages seemed muddled and confused from about 3pm so I phoned the ward to give them the heads up, at 5am this morning she called me and I presumed she was having a wobble as she’s hating having the tracheostomy, I tried to reassure her and asked to press her buzzer to get the nurse, nurse reported that they’ve put a commode in her room as she’s too weak to walk to her bathroom but this was the second time she’s been found wondering around confused overnight, no signs of infection anywhere and all her observations are fine. Mums base line is 100% alert and still working albeit part time, we’ve had confusion before 3 years ago after she fell and broke her ribs and developed a pneumothorax with an associated pneumonia. I’m planning on getting the 1st train up there this morning and should be there for 10am but is confusion after tracheostomy a common occurrence? nurse said her secretions are as expected which is good so no obvious signs of infection, I’ve asked them to make sure she hasn’t got a UTI as I know that often leads to confusion in older people. Any advice would be lovely - being so far away and not able to drive is a pain in the backside!