<prompt> In performing a tracheostomy, authorities agree thatThe strap muscles should be dividedThe thyroid isthmus should be preservedThe trachea should be entered at the second or third cartilaginous ringOnly horizontal incisions should be used  <response>: Although tracheostomy is occasionally an emergency procedure, it can be more effectively performed in an operating room where hemostasis and antisepsis are readily achieved. Most authorities recommend a horizontal incision; however, limited direct midline incisions have the advantage of not opening any unnecessary tissue planes and perhaps reducing the incidence of bleeding complications. Both approaches have advocates. In either case, the skin incision is made just below the cricoid cartilage, the strap muscles are spared and retracted, the thyroid isthmus is divided if necessary, and the trachea is entered at the second tracheal ring. The second and third tracheal rings are incised vertically, allowing placement of the tracheostomy tube. The first tracheal ring and the cricoid cartilage must be left intact. 