Does egr >90 indicate any issue with kidney function. bun and creatinine are normal. but bloodwork show severe malnourishment with high prealbumin and low bicarbonate. could this indicate starvation ketoacidosis and how to correct this?

EGR is not a recognized test of kidney function. If you mean GFR (glomerular filtration rate), it is entirely normal. If ESR (erythrocyte sedimentation rate), it is very high, indicating widespread and rather severe inflammation -- which may or may not eventually affect your kidneys. At this time, normal BUN and creatinine (and normal GFR) indicate no significant kidney problem.

Ketones are produced when fat and protein are broken down, instead of carbohydrate, during starvation. The main treatment for starvation ketoacidosis is refeeding with a high carbohydrate diet. However, care needs to be taken for avoiding refeeding syndrome with life threatening electrolyte imbalance when that person is refed. Good luck.