We claim the ornamental design for a medical tube holder, as shown and described.
FIG. 1 is a front view of a medical tube holder of the present invention, with two pairs of claws shown in a closed position;
FIG. 2 is a rear view thereof;
FIG. 3 is a plain view thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a perspective view thereof;
FIG. 8 is a front view of the medical tube holder of the present invention, with the two pairs of claws shown in an open position;
FIG. 9 is a rear view thereof;
FIG. 10 is a plain view thereof;
FIG. 11 is a bottom view thereof;
FIG. 12 is a left side view thereof;
FIG. 13 is a right side view thereof; and,
FIG. 14 is a perspective view thereof.
The broken line showing of parts of the drawings is included for the purpose of illustrating use and environment and forms no part of the claimed design.