Page 1639 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

1158 PART 10: The Surgical Patient

early recognition of hemopericardium. Hypotension, distended neck • The pericardial cavity is opened through a longitudinal vertical
veins, and hemopericardium confirm cardiac tamponade. pericardiotomy incision while avoiding the phrenic nerve.
• After evacuating the blood, digital pressure applied over a lacera-
Phases in Cardiac Tamponade: First phase: Initially cardiac output is tion will initially control hemorrhage followed by suture repair
maintained by an increase in the heart rate. (as mentioned above a Foley catheter or skin staple may be used
Second phase: Cardiac output decreases but blood pressure is main- to control the hemorrhage from a cardiac laceration as well).
tained by an increase in peripheral vascular resistance and a decrease in Aortic clamping using the Satinsky clamp is frequently required
pulse pressure secondary to catecholamine release. In these two phases, as discussed above.
there is time to take the patient to the operating room, which is more • Internal cardiac massage should be conducted with both hands
ideally suited for thoracotomy. Airway control and volume infusion are open from pressing the cardiac chambers between them to avoid
initiated prior to the operating room thoracotomy. perforation of the myocardium with the tips of the finger.
https://kat.cr/user/tahir99/
Third phase: In this phase there is profound hypotension, which
makes it unsafe to transport the patient to the operating room. Contraindications to Emergency Room Thoracotomy: Based on overall
Emergency room thoracotomy for decompression of the pericardial sac survival of 10% to 30% in penetrating injury and less than 1% of blunt
and identification and treatment of the cardiac laceration is warranted. injury, the following are recognized contraindications to emergency
room thoracotomy:
Control of Intrathoracic Hemorrhage: Less than 5% of intrathoracic
hemorrhage is massive requiring emergency room thoracotomy. The • Lack of expertise—unavailability of trained staff, equipment, or
mechanism is usually penetrating. Emergency room thoracotomy hospital policy
allows temporary clamping of the pulmonary hilum, clamping and • Penetrating thoracic injury with over 15 minutes of CPR and no
repair of major vascular sources of hemorrhage as well as repair of signs of life
cardiac wounds.
• Blunt injury with CPR greater than 5 minutes and no signs of life or
Open Cardiac Massage: Cardiac massage by external compression may asystole
maintain 20% to 25% of cardiac output and 10% to 20% of cerebral Other Chest Injuries: Although the following chest injuries do not
perfusion. Although this may be tolerated for brief periods of up to immediately threaten life, early diagnosis and treatment are essential
15 minutes, longer duration results in poor outcome. Emergency tho- to prevent significant morbidity and later mortality:
racotomy to allow open cardiac massage may result in better cardiac
output and cerebral perfusion than obtainable with closed cardiac 1. Lung contusion
compression especially in hypovolemic patients who have sustained 2. Blunt cardiac injury
penetrating trauma.
3. Aortic rupture
Thoracic Aortic Cross Clamping: In the hypovolemic patient, temporary 4. Esophageal disruption
thoracic aortic cross clamping allows redistribution of the limited 5. Diaphragmatic rupture
cardiac output to the cerebral and coronary circulation while volume
is replaced and the source of hemorrhage is addressed. The clamps 6. Rib fractures
should be removed as early as possible once volume replacement 7. Simple hemopneumothorax
has been achieved and the source of hemorrhage has been identi-
fied and controlled. Frequently the source of the hemorrhage may be A very brief discussion of the pathophysiology, diagnosis, and treat-
intra-abdominal and laparotomy in the OR should follow promptly ment of these entities follows.
(thoracic aortic cross clamping is contraindicated in the normovole- ■
mic patient and the risk of paraplegia should be recognized). LUNG CONTUSION
Although thoracic aortic cross clamping is lifesaving, reduction in This lesion results from direct trauma to the lung parenchyma, usually
blood flow distal to the clamp site results in acidosis, and severe, some- by a blunt mechanism, although it can occur from penetrating injuries
times irreversible ischemic damage including multiple organ failure as well. There is a wide spectrum of severity, ranging from very minor
particularly if cross clamping time exceeds 30 minutes. localized hemorrhage into the lung parenchyma to complete obliteration
of an entire lung or even bilateral involvement. This injury is missed
Bronchovenous Air Embolism: This has been described above. Urgent often because the respiratory failure that develops is not immediately
thoracotomy is required to salvage these patients and it may be neces- evident, and indeed, chest films may be completely normal initially. It
sary to conduct this in the emergency room. is essential, therefore, that the diagnosis be considered whenever there
is significant direct injury to the chest wall. Initially, there may be chest
Technical Aspects of Emergency Room Thoracotomy pain and minimal dyspnea or hypoxia. However, within hours there may
1. Equipment be slow deterioration in gas exchange and a progressive development of
• The emergency room thoracotomy tray should always be avail- radiologic densities on chest x-ray. As pointed out earlier, there may or
able and complete. Key elements are: scalpel, mayo scissors, chest may not be an associated flail chest.
retractor, Lebshke knife with mallet (or Gigli saw and sternal saw), The treatment is selective and is based on the degree of respira-
multiple 2-0 silk, 3-0 CV ethibond (including pledgeted), several tory impairment. When the gas exchange abnormality is minimal and
lap pads, two tooth forceps, Metzenbaum scissors, two De Bakey oxygenation and ventilation can be maintained without endotracheal
long forceps, large and small Satinsky clamps, De Bakey aortic intubation, close attention to fluid balance is required. However, fluid
clamps, two long needle holders, four tonsil clamps, Teflon pled- should not be restricted in a patient with lung contusion if fluid resus-
gets, internal defibrillator paddles, and cardiac resuscitation drugs. citation is required in a hemodynamically abnormal patient. Close,
2. Technique continuous monitoring of the hemodynamic and respiratory status is
• The left anterolateral incision with the option of extending to the essential; if there is no major hemodynamic or respiratory compromise,
right, across the sternum (clam shell thoracotomy) provides the most the patient will not require mechanical ventilation. The criteria for initia-
therapeutic options. If the clam shell incision is used, the internal tion of mechanical ventilation are outlined in earlier chapters, but certain
mammary arteries should be ligated once circulation is restored. associated disorders increase the likelihood that mechanical ventilation
The median sternotomy for anterior wounds and posterolateral will be needed. These include preexisting chronic respiratory failure and
incision for posterior wounds are also options. associated abdominal, thoracic, or central nervous system injuries.

section10.indd 1158 1/20/2015 9:21:08 AM