The ornamental design for a patient bolster, as shown and described.
FIG. 1 is a front view of a patient bolster showing my new design;
FIG. 2 is a rear view of the patient bolster;
FIG. 3 is a right side view of the patient bolster;
FIG. 4 is a left side view of the patient bolster;
FIG. 5 is a top view of the patient bolster;
FIG. 6 is a bottom view of the patient bolster; and,
FIG. 7 is a top front side perspective view of the patient bolster in use.
The dash lines in the drawings depict environmental subject matter and form no part of the claimed design. The dot-dash lines in the drawings depict symbolic break lines that form no part of the claimed design. Any portion of the article beyond the break lines form no part of the claimed design.