Treatment of blunt trauma to the thorax

Treatment JAMES

of Blunt

V. MALONEY,

Trauma

JR., M.D. AND LLOYD MCDONALD, M.D., Los Angeles,

From tbe Department of Surger,y, University of California Medical Center, Los Angeles, Calijornia. Tbis work was supported by grants-in-aid jrom tbe United States Public Healtb Service (H-2812 and HTS-5357), Wasbington, D. C. Dr. Maloney’s work was supported in part hy tbe John and Mary R. Markle Foundation, New York, New York. HE PROGRESSIVE increase in the speed of modern transportation has resuIted in a paraIIe1 increase in the frequency and importance of blunt trauma to the thorax. The mortality of thoracic injuries has steadily decreased during the past four decades. These improved cIinica1 resuIts are the outcome, not of new operative technics, but of the judicious use of adjuvants such as respirators, antibiotics and the control of bIood volume. ReIativeIy few significant contributions have been made in recent years to the treatment of bIunt trauma to the thorax. Many of the methods of therapy which have been used for decades have never been subjected to critica anaIysis or controlled observation. As a result, many empiricisms have deveIoped and currentIy serve as guides in cIinica1 treatment. It is probabIe that some of these empiricisms are valuabIe and result from accurate cIinica1 observation; others cIearIy have no basis in physiologic fact. It is the purpose of this presentation to examine critically the current methods of treatment of bIunt trauma to the thorax.

T

GENERAL

CONSIDERATIONS

Most patients with bIunt thoracic trauma are suffering from muItipIe injuries. In fact, it is the associated injuries which frequentIy Iead to the demise of the patient. This point is we11 made by the exceIIent study of Harrison and associates [I] which reviews the clinica resuIts of the treatment of 216 patients suffering from nonpenetrating injuries to the chest. The patient suffering from minor degrees of bIunt trauma, such as minor rib fractures, does American

Journal

of Surgery.

V&me

to the Thorax

109,April

1963

484

California

not present an emergency probIem. On the other hand, rapid and efficient resuscitative effort is required for those patients with major thoracic trauma who have cardiorespiratory distress when first seen by the physician. The rehef of respiratory distress may consist of the establishment of a cIear airway, the administration of intermittent positive pressure breathing for apnea or flail chest, or the reIief of tension pneumothorax. The principa1 probIem in the cardiovascuIar system engendered by blunt thoracic trauma is a diminished bIood voIume due to intrathoracic bleeding. The re-estabIishment of effective circulating bIood voIume by administration of bIood or bIood substitutes is of cardina1 importance. Perforating thoracic injuries are of a much more urgent nature than are the bIunt injuries under discussion here. Neverthetess, a standardized procedure for the rapid evaIuation of a11 thoracic injuries in the hospita1 emergency room is highly desirabIe. A patient in cardiorespiratory distress from a thoracic injury is given precedence over other emergency cases. He is immediateIy Iaid on a huoroscopic tabIe whiIe the surgeon dons semiopaque glasses to become dark adapted. He performs a rapid diagnostic evaIuation of the patient and observes the percussion note over each hemithorax, the puIse rate and character, the bIood pressure, the Ioudness of the heart tones and the character of the respiratory sounds on auscuItation. Within two to three minutes, dark adaptation permits ff uoroscopic examination adequate to detect the presence of a Iife threatening pIeura1 hemorrhage, cardiac tamponade or massive pneumothorax. If these conditions are not present, the physician may proceed in an orderly manner to take a compIete history, and examine the patient with meticuIous care. A detailed description of the cIinica1 evaIuation of the patient with thoracic injury is presented eIsewhere in this symposium by FeIton.

Treatment FRACTURED

of Blunt

to Thorax

patient from deveIoping sufficient negative intrapIeura1 pressure to exchange respiratory voIumes adequate for metaboIic needs. The resuit is that the patient quickIy becomes anoxic, hypercapneic and tachypneic. Tachycardia and present. These hypotension are frequently symptoms have in the past been attributed to the penduIum-like movement of “pendeIIuft,” air from one hemithorax to the other in association with the “paradoxica1” movement of the chest waI1 with each inspiration. A recent study in this Iaboratory [2] has demonstrated that pendeIIuft does not in fact occur under these conditions. The physioIogic deficit consists in the patient’s inabiIity to create an adequate degree of negative intrapleural pressure to ventiIate the Iungs (a change in the pressure-voIume diagram of the thorax resuIting from the thoracic injury). For many years, surgeons directed their attention to attempts at externa1 and internal fixation with traction on the sternum and ribs. These procedures were generaIIy unsatisfactory. In 1945, Mrch, Avery and Benson [3] emphasized the value of controIIed artificia1 respiration by intermittent positive pressure breathing in the treatment of flai1 chest. The results with intermittent positive pressure breathing are so dramatic that surgeons, once introduced to the method, abandon a11 attempts at interna or externa1 fixation. The genera1 steps to be taken in a case of fIai1 chest in which the paradoxing chest waI1 is sufficient to embarrass respiratory exchange are as foIIows: (I) AppIy the intermittent positive pressure respirations with either an appropriate mechanica device or with an ordinary anesthesia mask and breathing bag. If the patient is unconscious, endotracheal intubation wiI1 facilitate the administration of artificial respiration. (2) Perform a tracheotomy. The infIatabIe cuff may be removed from an ordinary endotrachea1 tube and appIied to a Iarge (No. 6, 7 or 8) tracheotomy tube; or, a cuffed endotrachea1 tube may be inserted directIy into the trachea via the tracheotomy wound. (3) The patient is hyperventirated by empIoying a high respiratory rate, or by increasing the positive inspiratory pressures. The patient uItimateIy wiI1 become apneic and the positive pressure respirator wiI1 assume contro1 of the patient’s respiration. Patience and skiI1, as we11 as a good mechanica respirator, are essentia1 to achieve apnea. The chemoreceptors of the human respiratory system are so constituted that if the

RIBS

The principa1 cIinica1 probIem associated with simple rib fracture is severe pain. Only infrequently is multiphcity of fractures or dispIacement of ribs adequate to produce the more dangerous complications of this condition. The more serious compIications of rib fracture include massive hemothorax, pneumothorax, and respiratory embarrassment due to the deveIopment of flai1 chest. SimpIe rib fracture calls for simple treatment which will not compound the patient’s injury and discomfort. Since the principal probIem is subjective pain, the most effective treatment consists of oral anaIgesics and rest to prevent excessive respiratory motion. AIthough injection of local anesthetic agents into the invoIved and adjacent intercosta1 nerves wiI1 give reIief of pain, the procedure is in itseIf a triai to the patient and the benefit is of short duration. Strapping of the affected hemithorax with adhesive plaster is a time honored, aIthough only partiaIIy effective, means of reducing the motion of fractured ribs. Both sides of the chest are prepared for strapping by shaving and by the application of compound tincture of benzoin to the skin. With the patient in a sitting position, and with the shoulder on the affected side depressed in order to decrease the voIume of the affected hemithorax, individua1 straps of 1 inch adhesive plaster are applied from the anterior axillary Iine on the contraIatera1 side, fixed to the skin over the affected ribs during expiration, and continued around the thorax to the posterior axiIIary line of the contralateral side. There are a number of Iimitations of this method. Some surgeons believe that the incidence of puImonary ateIectasis is increased foIIowing immobilization of one hemithorax. It is particularly ineffective in women with significant breast deveIopment. The method should not be applied where doubIe fractures of single ribs permit the taping to produce a depression of the thoracic wall. It is cIearIy not appIicabIe in a patient with biIatera1 rib fractures. FLAIL

Trauma

CHEST

The severeIy injured patient with multipIe rib fractures, frequently associated with a fractured sternum, has in the past presented one of the most diffIcuIt therapeutic probIems in the fieId of thoracic trauma. The Ioss of the structura1 integrity of the thoracic cage prevents the

485

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and McDonaId

patient is ventilated adequately to keep arterial oxygen saturation above 85 per cent and to reduce arterial pC0~ below 40 mm. Hg, the patient will inevitably become apneic. Some patience on the surgeon’s part may be required, since a prolonged period of hyperventilation may be required to blow off the carbon dioxide which has accumulated during a prolonged period of hypoventilation. A respirator capable of producing high instantaneous flow rates is essential to the success of the method.* The emergency resuscitators commonly used by fire departments and life guards have too low an instantaneous flow rate to be satisfactory for this application. If a high flow respirator is not available, the tank type of body respirator (Drinkeri) will serve equally well. It has been previously demonstrated that the pressure relationships and the physiology of the tank respirator employing negative intratank pressures are the same as those of intermittent positive pressure breathing machines [4]. The rate and depth of respiration should be adjusted so that the patient remains apneic, but begins spontaneous respiratory effort within fifteen to twenty seconds after the respirator is turned off. Hyperventilation adequate to produce prolonged periods of apnea may cause disturbances in acid-base balance. Artificial respiration is ordinarily continued for ten days to three weeks, at which time, the thorax shows a remarkable degree of stability. HEMOTHORAX

Hemothorax following blunt thoracic trauma is aImost always secondary to the injury of intercostal arteries or the pulmonary parenchyma by fractured ribs. After the initial emergency treatment is completed, the principal * The Bird Respirator, Bob Wells and Associates ConsuIting Engineers, Bird Oxygen Breathing Equipment, BeNlower, CaIifornia, and the Bennett Pressure Breathing Unit, Bennett Respiration Products, Inc., Los AngeIes, CaIifornia, are two respirators having such high instantaneous flow rates. The piston respirator of Mijrch [3] also produces high instantaneous flow rates. Some discussion has occurred regarding the relative merits of the pressure-flow cycled respirator (that is Bird, Bennett) and the voIume cycled respirator (that is, March). Since respirators of both designs have emergency reI;ase valves-set at a specilic pressure, both resDirators are in essence pressure cvcled. The choice is, therefore, one of preference rather than of physiologic merit. t Drinker-type fuI1 body respirator, J. H. Emerson Company, Cambridge, Massachusetts.

486

clinical problems concerns the handling of the residual blood in the pleural space. lZlinimal Hemothorax. Approximately 300 ml. of blood must collect in the pleural space before it is visible on a roentgenogram. A hemothorax containing approximately $00 ml. of blood may be observed without specific treatment. The remarkable absorptive powers of the pleura will ordinarily restore a chest roentgenogram to normal within ten days to two weeks. Major Hemothorax. The principal problem in the immediate treatment of a major hemothorax concerns the question of continued bleeding. Most authorities have recommended repeated aspiration of the accumulated blood from the pleural space until continued bleeding makes the need for operative intervention apparent. If there is concern about the possibility of continued bleeding, we believe repeated aspiration to be unwise. Even if repeated aspiration and chest roentgenograms should be done as often as every thirty minutes, a bleeding patient may have sufficient occuIt hemorrhage in the pleural space to threaten his life from hypovolemia. A much wiser procedure is to institute closed chest drainage through a No. 26 French drainage tube inserted through a trocar into the eighth or ninth intercostal space in the posterior axillary line and connected to water seal drainage. Connecting the chest drainage tube to approximateIy 20 mm. Hg negative pressure will help ensure that blood does not collect in the thorax. The advantage of this method is that it allows an immediate and accurate assessment of the volume of blood loss. Loss can be replaced by transfusion and the rate of bleeding precisely determined. The blood should be removed completely and immediately from the pleural space, since there is little to support the contention that aspiration of pIeural bIood will re-initiate hemorrhage. This fear is not based on sound physiologic grounds [y]. Although it has been recommended by some that the aspirated blood be replaced with air, there seems to be little clinical or physiologic reasons to support this advice. Late Treatment of Hemothorax. The remarkable absorptive powers of the pIeura make nothing more than watchful waiting necessary in the majority of patients who have clotted blood remaining in the thorax after blunt injury. Operative decortication in hemothorax has resulted in disappointing functional results,

Treatment

of BIunt Trauma

to Thorax

of watchfu1 waiting or repeated aspiration. In the past years, it has been usual to give no specific treatment for pneumothorax involving Iess than 20 per cent of the pIeura1 space. NormaIIy, such air absorbs in a period of seven to twenty days. Larger pneumothoraxes were treated by needle aspiration. The first aspiration usually did not affect the roentgenographic picture since the leak in the Iung parenchyma was rareIy seaIed at the time the first aspiration was carried out after trauma. There has been an increasing tendency in recent years toward a more aggressive treatment. The patient is admitted to the hospital, closed water sea1 drainage is established, and 20 mm. Hg negative pressure appIied to the pleural catheter. Re-expansion of the lung with apposition of the pIeura1 surfaces occurs immediateIy. AIthough the treatment requires hospitalization and incapacitates the patient for severa1 days, it has great economic advantages in that it quickly obIiterates the pneumothorax and permits the patient to return to his normal occupation within a few days. If the air leak in the lung parenchyma is significant, it is essentia1 that suction machines producing a high instantaneous flow rate be attached to the chest drainage bottle. nlachines designed for gastrointestinal suction, or those producing high negative pressures but having Iow instantaneous flow rates will not create a sufficient differential pressure across the lung to produce complete puImonary expansion. PIeuraI infection as a resuIt. of either the aspiration or intercostal drainage technic is aTmost unknown. Perforating thoracic wounds from large missiIes associated with parenchymal damage do have a significant incidence of infection. In these patients it is al1 the more essentia1 to obliterate the pIeural space by continuous closed catheter drainage.

and the use of enzymatic decortication causes significant morbidity due to infection [5]. We have previously reported a long term folIow-up study of forty cases of traumatic hemothorax which gave strong evidence in favor of a policy of nonoperative treatment. of retained bIood clots in the pIeura1 space [5]. PNEUMOTHORAX

Pneumothorax is much more common in association with penetrating than with bIunt thoracic trauma. A simple pneumothorax resulting from a leakage of air from the Iung must be differentiated from the more morbid conditions of bronchia rupture or rupture of the esophagus. Pneumothorax caused by bronchial rupture is discussed elsewhere in this symposium by i!lunneII. The diagnosis of esophageal rupture is confirmed by thoracentesis after the patient has ingested a small amount of coIored clye. Tension Pneumothorax. AIthough most patients can tolerate (with onIy miId distress) a complete pneumothorax which causes the Ioss of function of one lung, a tension pneumothorax is a life-threatening condition. Mediastinal shift severeIy impairs the function of the contraIateraI Iung. In addition to the severe respiratory distress, there may be a profound hypotension secondary to the depression of venous return to the heart caused by the positive intrathoracic pressure. The critica condition of the patient may not permit time for ffuoroscopic or radiographic examination. The diagnosis must be made immediately on the basis of trachea1 displacement away from the affected side and a hyper-resonant note with percussion on the affected side. Immediate treatment consists of the insertion of a large bore hypodermic needIe anteriorly into the affected hemithorax. Although this procedure wiI1 not expand the affected lung, it wiI1 suffrcient.Iy reIieve the pressure in the pIeura to permit function of the contraIatera1 lung and to aIIow norma venous return. Thereafter, cIosed thoracotomy drainage should be established. (Fig. I .) It is pertinent that the thoracotomy tube shouId be inserted anteriorIy in the treatment of pneumothorax in contrast to a posteroIatera1 insertion for hemothorax. Drainage is estabIished in the second or third intercostal space in the midclavicular line. Simple Pneumothorax. For many years satisfactory results have been obtained in the treatment of simpIe pneumothorax by a policy

TRACHEOTOMY

IN

THORACIC

TRAUMA

In recent years, the performance of a “routine” or “prophylactic” tracheotomy in patients suffering from thoracic trauma has been in vogue. Tracheotomy is recommended because it is stated that it reduces respiratory deadspace, reduces resistance to breathing, and permits the remova of trachea1 secretions. This rationale is so attractive that tracheotomy has probabIy enjoyed more popuIarity than is justified. Unfortunately, the rationale is unsound. Tracheotomy has been stated to 487

MaIoney

and McDonaId

FIG. I. These instruments are useful in performance of closed thoracotomy. Left, standard cIosed thoracotomy trocars illustrating how the catheter is threaded into the pIeura1 cavity after the obturator is removed. Center, a gallbladder trocar may be used when a thoracotomy trocar is not available. The Iarge bore needIe is used for the emergency treatment of the tension pneumothorax unti1 a thoracotomy trocar becomes avaiIabIe. Rigbt, in an emergency situation it is onIy necessary to incise the skin with a scaIpe1 and force the drainage tube through the intercosta1 muscIes with the aid of a KeIIy cIamp.

tions from the Iower airway for the starch spIitting enzyme, ptyaIin, indicates that the secretions aspirated from the Iungs immediately after tracheotomy are in fact almost pure saIiva. Tracheotomy eIiminates the body’s norma1 mechanism for preventing saIiva from entering the Iarynx. Much of the favorabIe cIinica1 impression regarding the benefits of tracheotomy on puImonary secretion, arises from the fact that tracheotomy permits the aspiration of saliva from the trachea; however, that wouId not have been there if the tracheotomy had not been performed. There can be no question of the benefit of tracheotomy in the presence of specific indications for its performance (that is, upper airway

reduce the work of breathing by ehminating the resistance of the upper airways. In fact, our measurements of the airway resistance indicates that the usua1 size tracheotomy tubes (No. 5, 6 and 7) increase many foId the resistance to air flow in the upper part of the respiratory tract. It is stated that a tracheotomy eIiminates the respiratory deadspace of the upper airway. In fact, the major portion of respiratory deadspace is located below the carina. The tracheotomy, therefore, has onIy sIight effect on deadspace. It has been stated that tracheotomy permits the removal of secretions of the Iower airway which might otherwise produce atelectasis and pneumonia. This is certainly the case; however, our analysis of the aspirated secre488

Treatment

of BIunt Trauma

obstruction; the presence of secretions in the lower airway which either the patient himself cannot raise by coughing, or which the physician cannot aspirate bv means of trachea1 suction; or flail chest requiring prolonged artificia1 respiration). Flowever, its “routine” or “prouse is open to some question since phylactic” the physiologic rationale upon which it is based is IargeIy in error. SUMMARY

In the past forty years there has been a progressive improvement in the morbidity and mortality of patients treated for blunt trauma to the thorax. Since the treatment of this condition is generaIIy nonoperative, it is apparent that these improvements have resulted from the application of the adjuvant methods of therapy: contro1 of bIood volume, appIication of respirators and the use of antibiotics. Progress in the treatment of blunt thoracic trauma

to Thorax

has been impaired by the existence of a number of empiricisms which do not have a basis in physioIogic fact. The best clinical results wiI1 arise from a program of treatment which is designed to restore function and relieve pain and which is based on sound physioIogic principles. REFERENCES I.

HARRISOK, W. H., JR., GRAY, A. R., COUVES, C. hI. and IIOWARD, J. M. Severe non-penetrating in-

juries to the chest: clinical results in the management of 216 patients. Am. J. Surg., IOO:713, 1960. 2. MALONEY, J. V., JR., SCHMUTZER, K. J. and RASCHKE, E. Paradoxical respiration and “pendelIuft.” J. Tboracic Surg., 41: 291, 1961. 3. MARCH, E. T., AVERY, E. E. and BENSON, D. W. Hyperventilation in the treatme1.t of crushing injuries of the chest. S. Forum, 6: 270, 1955. 4. MALONEY, J. V., JR. and WIIITTENBERGER, J. L. Clinical. applications of pressure used in the body respirator: An. J. M. SC., 221: 425, 195 I. MALONEY. J. V.. JR. The conservative management of traumatic hemothorax. Am. J. Surg., 93: 533, 1957.

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