Among the complications and accidents which may occur after a tracheotomy successfully performed,[5] none is commoner, and none, perhaps, is more to be feared, than the broncho-pneumonia which may develop at any time within the first three or four days, and especially in those cases where the operation has been rendered necessary by a diphtheritic inflammation of the throat or air-passages. Bronchitis is common when much blood has escaped into the trachea during the operation. The periodical and careful auscultation of the chest is therefore desirable, in order that the earliest physical signs of these morbid conditions may be detected. [Footnote 5: See Parker, "On Some Complications of Tracheotomy, with Illustrative Cases," _Lancet_, Jan. 24, Jan. 31, and Feb. 7, 1885.] {162} Secondary hemorrhage is rare: should it occur, the wound must be opened, enlarged if necessary, and the bleeding vessel sought for and secured. A slight hemorrhage may be checked by pressing the parts firmly about the tracheal tube and the use of styptics locally. When the pathological condition of the parts has demanded that the canula be worn for a long time, and in cases where sufficient care has not been taken to select one suited to the age of the patient or to the particular form of operation that has been chosen, perhaps to the needs of the special case, an ulceration of the anterior or posterior wall of the trachea, the result of the pressure of the lower edge of the tube or of its upper posterior and convex side, may occur. Usually, it happens on the anterior wall, rarely on both, and the main trouble to which they give rise lies in the repeated hemorrhages that proceed from the laceration of granulation-tissue, in changing the canula, for instance, and the descent of the blood into the trachea and lungs. Cases of extensive ulceration, with erosion of the large vessels at the root of the neck, and fatal hemorrhage, have been reported. Considerable care should then be exercised in so adapting a canula to a special case that it will lie as free as possible within the lumen of the trachea. Ulceration of the tracheal walls, it is claimed, never occurs with the right-angled canula of Durham. Occasional change of form in the canula or the use of canulas with rounded extremities (perforated with numerous slits) is often advisable when the tube is worn for a length of time.