Few procedures are as dramatic as open emergency thoracotomy. This technique can save a child from otherwise certain death when performed for the appropriate indications. However, this procedure must be used selectively, because only a small subset of patients will benefit (1,2,3,4,5,6,7,8,9,10,11,12,13,14). This chapter discusses both the indications for and the technique of open thoracotomy as performed in the emergency department (ED).

Although emergency thoracotomy is most successful when used to relieve pericardial tamponade (1,2,3,5,9,10,15,16,17,18,19,20,21,22,23), which is usually the result of penetrating injury to the heart, other purposes for this procedure include control of exsanguinating hemorrhage within the thoracic or abdominal cavity, redistribution of limited blood volume to the myocardium and brain, correction of an air embolism, and performance of open cardiac massage (9,13,15,24). One should focus on these objectives when performing the procedure, as the goal for the ED team is stabilization rather than definitive repair (5,8,25).

The concept of thoracotomy as a method of resuscitation is not new. Original descriptions of the procedure occurred in the late 1800s (12,13,26,27). In the years before the development of closed chest cardiopulmonary compressions, in-hospital arrests were sometimes managed by direct open chest cardiac compressions (8). Since the development of closed chest compressions as a means to perform resuscitation, open thoracotomy has been employed almost exclusively in the resuscitation of trauma victims who are in extremis. It has long been recognized that victims of trauma who succumb during the initial phase of resuscitation have often sustained significant injury to the heart or great vessels (28). In such cases, blood can collect between the heart and the pericardium, leading to pericardial tamponade, or the patient can experience exsanguinating hemorrhage into the thoracic cavity. In this situation, immediate thoracotomy to identify and repair injuries may be life saving. Occasionally, emergency pericardiocentesis (Chapter 71) may provide temporary relief and allow for thoracotomy under more controlled circumstances.

In terms of anatomy relevant to this procedure, a few differences exist between children and adults. For all patients, the wall of the thorax is composed of the muscles of the anterior and posterior chest wall, the ribs, and three sets of intercostal muscles—the external intercostal muscles, the internal intercostal muscles, and the innermost intercostal muscles. The external intercostal muscle exists as a membrane anterior to the midclavicular line, and the internal intercostal muscle is a membrane posterior to the midaxillary line. The neurovascular bundles containing the veins, arteries, and nerves lie along the lower margins of the ribs. The ribs themselves are very pliable in infants and young children, but in older children and adolescents the ribs are more like those of adults. Deep to the ribs is the parietal pleura, which is adherent to the interior of the thoracic wall, and deep to the parietal pleura is the mediastinum, which contains the heart surrounded by the pericardium and the origins of the great vessels.

Viewed from the standpoint of a thoracotomy, the right ventricle lies anterior, just beneath the sternum, with the left ventricle posterior and slightly lateral to the right ventricle. The left phrenic nerve lies on the pericardium on the lateral aspect of the left ventricle, placing it at risk during the procedure. Between the superficial tissues and the left ventricle is the left lung, which is invaginated by the ventricle. When the standard left lateral thoracotomy is used, the anterior and lateral walls of the left ventricle are visible once the left lung is retracted. Situated in a position cephalad to the heart itself
lie the great vessels; lateral and slightly posterior to these are the structures of the pulmonary hili. One distinct, if obvious, difference between adults and children is the size of the structures involved. This procedure can be much more difficult in a small child simply because everything is smaller (29,30).

The physiologic considerations involved in pediatric thoracotomy are likewise similar to those in the adult procedure. Direct trauma to the heart often allows blood to accumulate between the heart and the pericardial sac, particularly if the hole in the pericardium is small, because the pericardial defect will often partially or fully seal itself. Even a small amount of blood in the space between the heart and the pericardium can restrict cardiac function. In a small child, this can be a few milliliters. Fortunately, removal of even a portion of this fluid often results in dramatic improvement in cardiac output. Conversely, if the hole is large or fails to seal, then the blood exits the heart into the mediastinum or the thorax. The child can exsanguinate rapidly in this circumstance.

It is for relief of pericardial tamponade and correction of a direct penetrating injury to the heart that thoracotomy is most likely to be successful, but it also may be used in cases of direct injury to the great vessels, to highly vascular abdominal structures, or to the pulmonary hilar structures. In the aforementioned situations, thoracotomy is done to halt exsanguinating hemorrhage into the thoracic or abdominal cavities. In cases of intra-abdominal hemorrhage, thoracotomy allows the interruption of blood flow to the abdomen (by clamping the aorta) and selective perfusion of the brain and the cardiopulmonary system. Experimentally, direct (open) cardiac compressions result in better cardiac output than do indirect (closed) cardiac compressions (31), maintaining homodynamic variables almost in a normal physiologic range (32).

Historically, emergency thoracotomy had its inception as part of the resuscitation of trauma victims in the 1960s and 1970s, and since then indications for performance of this procedure have been the subject of intense investigation. Initially, virtually any victim of trauma who arrived in full cardiopulmonary arrest, who arrested in the resuscitation area, or who failed to respond to maximal resuscitation efforts was considered a candidate for this procedure. However, with experience, indications for thoracotomy have become clearer (7,33,34,35,36,37,38,39,40,41,42,43,44). In virtually all studies of resuscitative thoracotomy, victims of blunt trauma have fared far worse than victims of penetrating trauma. This difference almost certainly reflects both the high incidence of head trauma associated with blunt trauma and the fact that injury in blunt trauma often involves multiple organs (4). In any case, survivorship with good neurologic outcome is rare for blunt trauma victims who arrest during the prehospital phase of resuscitation (4,14).

Victims of penetrating trauma can be further subdivided into victims of shooting and victims of stabbing. While penetrating trauma carries a better prognosis overall, shooting victims are less likely to survive than are victims of stabbing (2,11,16,24,45). The most reasonable explanation for this difference in survivorship is that stabbing is a relatively low velocity injury that often results in damage to a single organ, while shooting, primarily because of the higher velocity, often involves multiple organs and far more tissue destruction. In the case of penetrating trauma, survivorship appears to be determined by the time elapsed between the event and the institution of definitive treatment. Most large studies have few survivors who had undetectable vital signs for more than a few minutes (1,2,11,12,13,16).

Unfortunately, little information is found in the medical literature dealing specifically with children (1,14,22,23,46). To date, only four studies of resuscitative thoracotomy have been restricted to patients <18 years of age. These studies demonstrate a similar outcome pattern to those involving adults, with survivorship being rare in blunt trauma victims. A total of 142 patients in the four studies underwent emergency thoracotomy; 85 sustained blunt trauma and 57 penetrating trauma. Of the 85 victims of blunt trauma, 2 survived, whereas 7 children who had a penetrating injury survived to hospital discharge. Of the three studies that specifically list the ages of the involved children, no patient younger than 15 years of age survived. This reflects both the high incidence of blunt trauma in young children and the little appreciated fact that although children may be better able to resist full cardiopulmonary arrest than adults, once arrested they are unlikely to recover (4,47,48). Additionally, these results demonstrate the level of interpersonal violence among teenagers that ultimately leads to penetrating injuries (23,25).