EDITORIALS
Management of Flail Chest
T
his issue of The Annals contains an important article by Dr. Trinkle and his co-workers on the management of flail chest (p 355). The authors emphasize that a blunt injury to the thorax occurring with sufficient force to fracture several ribs inevitably produces a pulmonary contusion of the underlying lung. Frequently, it is the pulmonary contusion rather than the fractured ribs which interferes with adequate oxygen exchange. Traditional teaching has been that a weakened thoracic cage must be supported by means of a mechanical ventilator for a period generally equivalent to that required for the fractures to heal. Dr. Trinkle and his group have nicely emphasized that mechanical stabilization of the thorax may not be necessary in all patients and, when it is needed, may only be required for a short period. Their indication for ventilatory support was an arterial Poz of less than 80 mm Hg, and support was continued only as long as blood gas determinations with the patient breathing room air fell below this level. The authors do not maintain, although their title does suggest it, that mechanical ventilation is never required. Their thesis is that the indications are more than simply the presence of fractured ribs. In reviewing their data, it is apparent that the patients treated without mechanical ventilation were a highly selected group who did not appear to suffer from severe ventilatory insufficiency. The initial arterial Pcoz values were all within normal range or slightly lower, indicating that ventilation was not seriously impaired. A more precise method for deciding which patient requires ventilatory support is to measure the tidal volume and preferably the dead spacehidal volume ratio. These measurements, in conjunction with arterial blood gases, provide clear indications of ventilatory insufficiency. The complication rate among those patients receiving ventilatory support was high but consisted almost entirely of bronchopneumonia that was nearly always associated with the performance of a tracheostomy. The authors emphasize quite properly that tracheostomies should be reserved for patients in whom the need for prolonged ventilatory support has been demonstrated. Initial ventilatory support should be started with an endotracheal tube, preferably of the floppy cuff variety. After five to six days of such support, the patient who demonstrates evidence of ventilatory insufficiency when the ventilator is discon-
480
THE ANNALS OF THORACIC SURGERY
Editorial
nected should be subjected to tracheostomy. Dr. Trinkle and his associates have performed a valuable service by emphasizing the importance of treating the whole patient rather than just the obvious skeletal injury. Nevertheless, a note of caution must be sounded. Patients with multiple fractured ribs frequently have associated injuries, such as long bone fractures, which may in themselves lead to a variety of the respiratory distress syndrome and necessitate mechanical ventilatory support. Careful observation with frequent measurements of tidal volume and arterial blood gases is essential. If signs of ventilatory insufficiency are indicated by an arterial Pco2 greater than 44 mm Hg, an arterial Po, of less than 75 mm Hg while breathing room air, or a tidal volume of less than 4 ml per kilogram of body weight, then intubation with an endotracheal tube must be promptly carried out and mechanical support of ventilation commenced. S. R. POWERS, JR., M.D. Department of Surgery Albany Medical College of Union University Albany, N.Y. 12208
VOL. 19, NO. 4, APRIL, 1975
48 1
Management of Flail Chest
T
his issue of The Annals contains an important article by Dr. Trinkle and his co-workers on the management of flail chest (p 355). The authors emphasize that a blunt injury to the thorax occurring with sufficient force to fracture several ribs inevitably produces a pulmonary contusion of the underlying lung. Frequently, it is the pulmonary contusion rather than the fractured ribs which interferes with adequate oxygen exchange. Traditional teaching has been that a weakened thoracic cage must be supported by means of a mechanical ventilator for a period generally equivalent to that required for the fractures to heal. Dr. Trinkle and his group have nicely emphasized that mechanical stabilization of the thorax may not be necessary in all patients and, when it is needed, may only be required for a short period. Their indication for ventilatory support was an arterial Poz of less than 80 mm Hg, and support was continued only as long as blood gas determinations with the patient breathing room air fell below this level. The authors do not maintain, although their title does suggest it, that mechanical ventilation is never required. Their thesis is that the indications are more than simply the presence of fractured ribs. In reviewing their data, it is apparent that the patients treated without mechanical ventilation were a highly selected group who did not appear to suffer from severe ventilatory insufficiency. The initial arterial Pcoz values were all within normal range or slightly lower, indicating that ventilation was not seriously impaired. A more precise method for deciding which patient requires ventilatory support is to measure the tidal volume and preferably the dead spacehidal volume ratio. These measurements, in conjunction with arterial blood gases, provide clear indications of ventilatory insufficiency. The complication rate among those patients receiving ventilatory support was high but consisted almost entirely of bronchopneumonia that was nearly always associated with the performance of a tracheostomy. The authors emphasize quite properly that tracheostomies should be reserved for patients in whom the need for prolonged ventilatory support has been demonstrated. Initial ventilatory support should be started with an endotracheal tube, preferably of the floppy cuff variety. After five to six days of such support, the patient who demonstrates evidence of ventilatory insufficiency when the ventilator is discon-
480
THE ANNALS OF THORACIC SURGERY
Editorial
nected should be subjected to tracheostomy. Dr. Trinkle and his associates have performed a valuable service by emphasizing the importance of treating the whole patient rather than just the obvious skeletal injury. Nevertheless, a note of caution must be sounded. Patients with multiple fractured ribs frequently have associated injuries, such as long bone fractures, which may in themselves lead to a variety of the respiratory distress syndrome and necessitate mechanical ventilatory support. Careful observation with frequent measurements of tidal volume and arterial blood gases is essential. If signs of ventilatory insufficiency are indicated by an arterial Pco2 greater than 44 mm Hg, an arterial Po, of less than 75 mm Hg while breathing room air, or a tidal volume of less than 4 ml per kilogram of body weight, then intubation with an endotracheal tube must be promptly carried out and mechanical support of ventilation commenced. S. R. POWERS, JR., M.D. Department of Surgery Albany Medical College of Union University Albany, N.Y. 12208
VOL. 19, NO. 4, APRIL, 1975
48 1
