Device (1) for monitoring cardiac compression being applied to a pateitn comprises a body to overlie and contact the sternum, preferably of width no greater than the width of the sternum. The device includes indidication means (9) responsive to the force applied to the body by the user for providing an indication of the cardiac compression applied to the sternum. Also disclosed is a resuscitation mask adapted to be place over the mouth of a patient, the mask includes a nostril closing means adapted to press against the sides of the nose to close the nostrils when the mask is sealed against the face of the patient.