Do you recommend prophylactically adding heparin to the dialysate in patients hospitalized for peritoneal dialysis associated peritonitis given higher incidence of fibrin-associated catheter issues?

For patients with peritonitis, IP heparin (500 units/L) can be helpful to prevent catheter occlusion when the drain fluid (effluent) is cloudy. Note that while most antibiotics are stable when admixed into peritoneal dialysate, after heparin is added, the length of stability may be shortened for certain antibiotics. The latest iteration of the ISPD Peritonitis Guidelines provides some information regarding common antibiotics and stability with heparin.

Li et al., PMID 35264029

We do not prophylactically add heparin to dialysate in patients with peritonitis. We have that as a "prn" order, if necessary, but the frequency with which it is needed is low, no more than 10% of the time. As each addition to a dialysate bag is associated with a small possibility of introducing infection, we prefer to avoid that risk.