Spontaneous episodes of shortness of breath?

Hi everyone, just wondering if anyone else has experienced this.

My dad has stopped treatment after being diagnosed with rGBM unmethylated wild type back in July 2024. He did the SOC and Avastin with the last dose of Avastin on the 15th of Jan. He was completely functional minus some issues reading and writing, until he had a fever at the end of December which ended up resulting in him losing his balance, becoming apathetic, extreme mood swings, lack of appetite, issues with taste, increased confusion etc. We stopped the Avastin and have now started palliative care and essentially end of life care. Since then he’s vomited 1L in one night spontaneously with a 10/10 headache and then we started 4mg Dexamethasone once a day the very next day. Tonight he had an episode of extreme shortness of breath and feeling like he couldn’t get a full breath in. He was taking about 22 breaths per minute but this resolved after 1-2 minutes.

These symptoms make me think it’s the tumour pressing on the brain stem but I wanted to know if anyone has had similar experiences? I have had a look at the brain cancer hospice timeline and end stage landmarks too.