An apparatus comprises a body, a shaft assembly, and an end effector. The shaft assembly extends distally from the body. The end effector is located at a distal end of the shaft assembly. The end effector comprises an ultrasonic blade, a clamp arm, and a sleeve. The ultrasonic blade is configured to vibrate at an ultrasonic frequency. The clamp arm is configured to move toward the ultrasonic blade. The sleeve extends along at least part of the length of an outer portion of the ultrasonic blade or the clamp arm. The sleeve is configured to prevent tissue from contacting a portion of the ultrasonic blade or clamp arm covered by the sleeve.
