thanks mh. what i found challenging treating this patient was:
1) mh is contraindicated in view of her high peep
2) manual techniques such as percussion and vibration are limited because of the low platelets (she has multiple areas of spontaneous ecchymoses, probably just from nursing care and turning)
3) head down tilt gravity assisted drainage is poorly tolerated, as her bp is often on the high side.

nevertheless, i have persisted with modified gad (ie without head down tilt) and vibrations +++ (as gentle as i possibly can, considering that chest wall compliance is low with in the presence of high peep too) - at least 3-4 times within a 24 hour cycle. some resolution of cxr this morning during the round, but i wonder if it's really due to physio or just a natural progression from antibiotic therapy and ventilation.

:hat