Trauma Flashcards
Mortality associated with thoracic trauma requiring exploration?
Operative mortality of patients requiring emergency thoracotomy:
- 67% of patients blunt injury
- 17% of patients with penetrating injury
Overall mortality of thoracic trauma
10%
Extent of the diaphragm
Skin margin:
Anterior: umbilicus and nipple (fourth intercostal space)
posterior: inferior tip of the scapula posteriorly.
Bony:
The bony landmarks for the diaphragm extend from T8 to L1.
With expiration, the diaphragm rises to the level of the nipple and T5.
Superior margin of the chest
zone 1 of the neck :
cricothyroid membrane to the sternal notch
Volume which the pleura can accommodate
In the adult, each pleural space can accommodate as much as 3 L of blood. This large volume loss will cause rapid progression to class IV hemorrhagic shock and exsanguination
Volume which the pericardium can accommodate
In contrast, the pericar- dium can only acutely accommodate an additional 100 to 200 mL of blood before venous return and diastolic filling are impaired, causing cardiac tamponade and shock.
Class I hemorrhage - volume of blood loss
Class I:
Blood Volume Loss <15%
Adult blood loss <750 ml
Class II hemorrhage - volume of blood loss
Blood Volume Loss: 15-30%
Adult: 750-1500 ml of blood loss
Class III hemorrhage - volume of blood loss
Blood Volume Loss: 30-40%
Adults: 1500-2000 ml blood loss
Class IV hemorrhage - volume of blood loss
>40%
>2L
Class I hemorrhage -Characteristics
- Blood Volume Loss: % & ml
- Cardiovascular:
- pH
- Respiratory
- Neurologic
- Skin
- Delayed Capillary Refill
- Renal
Characteristics
Blood Volume Loss <15%
Adult blood loss <750 ml
Cardiovascular
- Heart Rate normal or mild increase
- Pulses normal
- Blood Pressure normal
pH normal
Respiratory: Rate normal
Neurologic: Slightly anxious
Skin
- Warm and pink
- Capillary Refill brisk (<2 seconds)
Renal: Normal urine output
Adults: >0.5 ml/kg/hour (>30 cc/hour)
Children: >1 ml/kg/hour
Infants <1yo: >2 ml/kg/hour
Class II hemorrhage - Characteristics
- Blood Volume Loss:% / ml
- Cardiovascular
- pH
- Respiratory
- Neurologic
- Skin
- Renal
Characteristics
- Blood Volume Loss: 15-30%
- Adult: 750-1500 ml of blood loss
- Cardiovascular
- Tachycardia
- Diminished peripheral pulses
- Blood Pressure normal
- Normal pH
- Respiratory
- Mild Tachypnea
- Neurologic
- Irritable
- Confused
- Combative
- Skin
- Cool extremities
- Mottling
- Delayed Capillary Refill
- Renal
- Oliguria
- Increased specific gravity
Class I hemorrhage % volume blood loss
class I 40%
Class IV Shock: % volume blood loss
>40%
Among severely traumatized patients, __of deaths are thought to be secondary to chest trauma.
25%
?% of unrestrained individuals in MVC sustain chest trauma
50%
Initial management of tracheobronchial injury
Intervention will be directed initially toward the pneumo- thorax, as the tracheobronchial injury (TBI) is often not yet suspected. Persistent pneumothorax or air leak after placement of a chest tube should alert the physician to the possibility of a TBI. Insertion of a second chest tube is required in these cases. TBI must be suspected if a patient deteriorates rapidly following endotracheal intubation. Because of positive pressure ventilation and loss of negative intrathoracic pressure on inspiration, air leak is increased, followed by increasing difficulties with oxygenation and ventilation.
Anatomy of most tracheobronchial injuries
most within 2 cm of the carina most within the right mainstream bronchus followed by lower trachea
Tension Pneumothorax presentation (two ways)
-
An awake patient:
- Able to mount a compensatory response increasing his respiratory rate, tidal volume, negative inspiratory pressure, and chest expansion. –> The physiologic insult: primarily hypoxic with progressive respiratory decompensation; hypotension is the terminal event of hypoxic cardiac failure or respiratory arrest.
-
Sedated and ventilated patients:
- cannot compensate, and show a greater degree of impeded venous return from both the intrapleural pressure and the PPV. The deterioration is much more rapid, resulting in more rapid cardiogenic shock once the central venous pressure equals the intrapleural pressure, and causing complete obstruction of venous return.
how often is a classic tension ptx seen in an awake vs intubated patient
TPTX show that tracheal devi- ation, oxygen desaturation, and hypotension are actually INCONSISTENT findings in (awake) spontaneously ventilating patients (
warning signs of tension ptx on ventilated patient
PPV who suddenly deteriorates with falling SaO2, rapidly becomes hypotensive without a clear reason, becomes difficult to bag, or shows raised peak inspiratory pressures on a ventilator
Indications for immediate needle decompression
- Traumatic arrest 2. Loss of blood pressure or pulse during resuscitation 3. Increased difficulty to bag/raising peak ventilatory pressures combined with hypotension 4. Hypotension or hypoxia/respiratory distress with decreased/absent breath sounds on one side or palpable subcutaneous emphysema.
% of lung contusion which requires mech ventilation
18-30%
Rib fractures consistent with lower abdominal injuries
9-12th
How much blood need be in the chest to see on cxr
150-200ml
comparison of sensitivity of E-Fast and cxr in showing blood in the pleurae
Many CXRs done in trauma are performed on the supine patient,–> portable CXR on a supine patient has a sensitivity of 40% to 60% in ruling out hemothorax. E-FAST can identify as little as 20 mL of fluid in the pleural cavity, and has shown sensitivities of greater than 96% in detecting hemothorax.
Massive hemothorax
A massive hemothorax is defined as the presence of 1500 mL or more of blood in the thoracic cavity, and is the classic indication to proceed with an urgent thoracotomy.
The most common complication after pericardiotomy for trauma is
postpericardiotomy syndrome.
___% of caustic injections occur in children __ years old
80% of caustic ingestion occurs in children
how long until the caustic effects of a swallowed battery
Severe injury results within 1 hour of ingestion from the extravasation of highly toxic potassium or sodium hydroxide contained in the battery
important difference in accidental ingestions vs suicide attempts
volume - accidental are significantly less
factors which determine the severity of the effect of a caustic ingestion
- pH of the ingested substance 2. Whether the substance is solid or liquid 3. Duration of exposure 4. Quantity ingested
Anatomically, where in the esophagus are caustic injuries the most severe
at areas of the greatest narrowing, with the greatest narrowing
time course of esophageal injury to the esophagus
However in the ensuing 24 to 48 hours the damaged layers begin to degenerate and become infi ltrated with lymphocytes. Angiogenesis and migration of fi broblasts begin between the second and fourth day after injury. By 1 week, the necrotic tissue has sloughed off and ingrowth of granulation tissue begins. The wound is clearly demarcated by this time, and the risk of perforation is probably the highest owing to the low tensile strength of the collagen deposited in the wound.
Gastric lavage with corrosive injury to esophagus
Gastric lavage is also contraindicated, owing to the risk of esophageal perforation and aspiration of gastric contents.
First degree mucosal injury to esophagus - depth
Mucosal
First degree mucosal injury to esophagus - endoscopic appearance
Mucosal hyperemia and edema
Second degree mucosal injury to esophagus - depth
Transmucosal, with or without involvement of muscularis.
Second degree mucosal injury to esophagus - endoscopic appearance
Hemorrhagic, exudative, ulcerative pseudomembranes
Third degree esophageal injury - depth
Full-thickness injury with extension into periesophageal Complete obliteration of esophageal lumen by massive tissue. May involve mediastinal or intraperitoneal organs.
when should endoscopy be fist performed after caustic ingestion
early because the risk of rupture increases at 24 to 72 hours
Steps to address potential sytemic air embolization?
(1) Ventilation :
(a) Positive pressure ventilation should be avoided if possible.
(b) If intubation and assisted breathing is required, pressures should be minimal.
- Vigorous hyperventilation is not desirable.
- Selective lung ventilation with a double-lumen tube or endobronchial blocker can exclude the damaged lung.–>
(c) stopping ongoing gas entrainment.
(d) Cross-contamination of the other lung by blood is also arrested.
(2)Oxygenation & Gas
(a)Oxygen:
- 100% oxygen administration is good, irregardless of measured oxygen saturation.
- Room air (80% nitrogen) is essentially insoluble in blood.
- Intravascular oxygen bubbles will resolve much faster than air emboli.
(b) Nitrous oxide:
1. increases bubble sizeà should be avoided
(3) Intravascular Volume Status
(a) should be kept generous _within lim_its
(b) volume depletion enhances the pressure gradient from airway to pulmonary veins, potentially worsening this complication.
(4) If Hemotypsis is present:
(a) prompt bronchoscopy may exclude large airway injury.
(5) Thoracotmy:
(a) Emergency thoracotomy with mass hilar clamping may be necessary if:
- cardiac tamponade cannot be excluded
- lung bleeding continues.
(b)Intracoronary Air
- should lead to Trendelenberg positioning
- aspiration of air from the left ventricular apex.
- Institution of cardiopulmonary bypass has also been advocated..
(c) Hyperbaric therapy?
1. After hemodynamics have been stabilized hyperbaric therapy may be of benefit if cerebral air embolism has occured.
Emergency thoracotomy - steps if intracoronary air is seen?
- Intracoronary Air
- should lead to Trendelenberg positioning
- aspiration of air from the left ventricular apex.
- Institution of cardiopulmonary bypass has also been advocated..
