July 7, 2025

For the next four weeks, this newsletter will focus on the basics of blunt and penetrating trauma. This is an extremely broad topic that could fill years’ worth of newsletters; therefore, the topics chosen will focus on 

1. Mechanism of injuries and associated energy transfer 

2. Trauma anatomic regions of the torso and retroperitoneum 

3. Nonhemorrhagic injury patterns 

4. Extremity trauma principles 

5. Recognizing hemorrhage 

6. Treating hemorrhage in the trauma bay 

7. One blunt and one penetrating patient care case to highlight how to diagnose and treat the trauma patient 

This week, the topics are understanding mechanisms of injury and associated energy transfer, and the trauma anatomic regions of the torso and retroperitoneum.  

Understanding how to care for a trauma patient requires recognition and appreciation of multiple pieces of information. The collection of crucial information starts at the scene of the trauma with a description of the mechanism of injury. A thorough report of the mechanism of injury is essential to understanding the amount of energy or force applied to the body to predict injury patterns. Traumatic mechanisms can be either blunt or penetrating. Blunt injuries include compression forces directly onto the tissue and/or acceleration/deceleration forces and include mechanisms like falls, motor vehicle collisions, motorcycle collisions, and sports injuries. Acceleration/deceleration forces are also referred to as shear injuries and occur when patients are moving at a high speed and then quickly stop, causing different parts of the body to move forward while fixed structures inside the body stay in place (such as during a fall from a roof). Details about the height of a fall are important, as the higher the height, the greater the energy applied to the body and the worse the injury pattern. In addition, whether the fall was mechanical, like a trip over a carpet, or syncopal from passing out is important information, as this will determine further evaluation when hospitalized. Lastly, the speed of the vehicle and seatbelt use are also important in predicting injury patterns as, again, the greater the energy, the more severe the injuries.  

Penetrating injuries include gunshot wounds, stabbings, and blast injuries. As opposed to blunt injuries where energy can spread, penetrating injury patterns follow the trajectory of the bullet or knife. Establishing this trajectory helps to predict injuries. Gunshot wounds have higher energy than stab wounds, so tissue trauma may spread beyond the bullet’s trajectory. For stab wounds, injuries follow the trajectory of the knife or instrument alone. Blast injuries, often seen in the military or industrial situations, cause local tissue destruction and spread depending on the amount of energy applied.  

While the mechanism of injury and associated energy help to predict injuries, so do the involved trauma anatomic regions. Trauma anatomic regions of the torso include the cardiac box, thoracoabdominal, flank, anterior abdomen, and pelvis. The cardiac box includes the heart, great vessels, and all the structures of the mediastinum. It is bordered by the clavicles superiorly, the xiphoid process inferiorly and nipples laterally, both on the anterior chest and back. The thoracoabdominal region is a difficult region to diagnose and treat, as injuries are frequently in both the chest and abdomen. The thoracoabdominal region is bordered superiorly by the nipples, inferiorly at the costal margin, and extends circumferentially around the entire body. The flank is on the lateral aspect of the torso, bordered by the inferior tips of the scapula to the iliac crest inferiorly and anterior and posterior axillary lines. Intraperitoneal, retroperitoneal, chest, and pelvic injuries can all occur with a blunt or penetrating injury to the flank. The anterior abdomen includes the portion of the torso bordered by the costal margins superiorly, the inguinal ligaments inferiorly, and the anterior axillary lines laterally. Chest, intraperitoneal, retroperitoneal, and pelvic injuries are all possible in this region, including solid organ (liver, spleen, kidneys), hollow viscus, and major blood vessel injuries. The pelvis includes the area bordered by the iliac crest to the upper third of both thighs and can include intraperitoneal and extraperitoneal injuries, especially the challenging iliac and femoral vessels, and the ureters and bladder. As seen below, there is some overlap between these regions, but understanding the surface anatomy and associated internal organs helps to anticipate what may be injured and how to best approach the next steps in care.  

The retroperitoneum is a unique trauma anatomic region in the torso, as injuries and bleeding in the retroperitoneum can be contained by the tamponade effect of the peritoneum. The retroperitoneum is divided into three zones, which are evaluated during exploration of the abdominal cavity. Zone 1 contains the aorta, inferior vena cava, and the mesenteric vessels. Zone 2 is bilateral and contains the kidneys and the associated renal artery/vein. Zone 3 is the extraperitoneal pelvis and includes the iliac vessels and high-flow, small vessels around the sacrum.  

Taking into account the trauma mechanism, associated energy and trauma anatomic regions involved all help to organize our approach to diagnosing and treating blunt and penetrating injuries to the torso.  

Next week, the topics will be nonhemorrhagic injury patterns and extremity trauma principles.

All the best,

Joseph Posluszny, MD

July 14, 2025

Last week’s topics focused on the trauma mechanisms, associated energy, and trauma anatomic regions of blunt and penetrating injuries to the torso. While the source of shock for trauma patients is almost always from hemorrhage, major nonhemorrhagic injuries can be significant and life-threatening. In addition, understanding the principles of extremity trauma is essential to caring for the complex trauma patient. Therefore, the topics for this week’s newsletter are nonhemorrhagic injuries of the torso and extremity trauma principles.  

Four major nonhemorrhagic injuries of the torso are blunt cardiac injuries, blunt cerebrovascular injuries, abdominal hollow viscus injuries/seat belt sign, and rib fractures.  

• Blunt cardiac injury occurs when the heart absorbs direct energy, such as when the chest hits the steering wheel in a motor vehicle collision. When the heart is bruised, the resultant tissue damage and swelling may interfere with the normal conduction system that the heart uses to maintain its steady rhythm. If this conduction system is altered, then the patient can develop arrhythmias, which are the most common sequela of blunt cardiac injury. Most patients with evidence of anterior chest wall trauma should have an EKG to screen for arrhythmias. Rarely is the impact so great that a heart valve will rupture, leading to significant instability and the need for surgical intervention.  

• Blunt cerebrovascular injuries occur when there is a deceleration force to the neck. Small tears in the lining of the carotid or vertebral arteries can occur when a patient has an injury to the cervical spine or when the patient has a seat belt injury across the neck.  

When this injury pattern is present, a CT angiogram of the neck should be obtained to screen for blunt cerebrovascular injury. Small tears in the vessels may lead to turbulent flow and stroke. Typically, these small tears are treated with aspirin or anticoagulation to reduce stroke risk. Injuries requiring stenting or surgery are very rare.  

• Abdominal hollow viscus injuries/seat belt signs follow a similar deceleration mechanism as blunt cerebrovascular injuries. When seat belts are worn along the lower abdomen instead of the hips and upper thigh, the force of the seat belt against the lower abdomen during the deceleration of a motor vehicle collision is transmitted to the underlying hollow viscus/intestine which can either immediately tear the intestines or sometimes lead to a delayed injury, as the bruise of the bowel evolves from a small injury to a deeper one. Patients with a seat belt sign who do not have peritonitis and require immediate surgery are monitored for the development of worsening abdominal pain overnight.  

• Rib fractures can occur with both blunt and penetrating mechanisms of injury. While rib fractures can be painful and impact a patient’s respiratory function, the lower ribs protect the upper abdominal solid organs, such as the liver and spleen. Lower rib fractures should prompt investigation for injury to these solid organs.  

Extremity injuries often occur concurrently with torso trauma. Evaluating extremity trauma focuses on bone, nerve, muscle, and blood vessel injuries. The focus here will be on blood vessel trauma. Extremity trauma can include both arterial and venous injuries. The vein injuries can be treated either by repair of the vessel or by vessel ligation. The vein may be ligated in the setting of hemorrhagic shock, as restoration of venous flow is not necessary. Arterial blood supply is essential, though, and can be treated with direct repair of the vessel, patching of a small injury, or a bypass. While distal arterial blood flow to the limb is compromised by the injury and during the repair process, the byproducts of ischemia build up in the tissues. As the extremity is later revascularized, an ischemia-reperfusion injury may occur, leading to increased swelling of the muscular compartments of the affected limb. If the swelling is severe enough, then compartment syndrome may develop. It is essential to recognize compartment syndrome as muscle necrosis can occur within several hours. Compartment syndrome can be recognized by the 6 P’s:

1. Paresthesias

2. Pain

3. Pallor

4. Poikilothermia

5. Paralysis

6. Pulselessness 

Once the limb is paralyzed or pulseless, the muscle may have already died and may never recover. To release the pressure on the muscle compartment, when compartment syndrome is suspected, a fasciotomy can be performed to allow swelling of the muscle outside of the strong fascial tissue.   

Next week, the topics will focus on recognizing hemorrhage and how to treat hemorrhage in the trauma bay.

All the best,

Joseph Posluszny, MD

July 21, 2025

This week’s goal is to understand how to recognize and treat hemorrhage. Almost all shock in the trauma bay is due to hemorrhage, so recognizing and treating hemorrhage is a mainstay in the care of the trauma patient. Despite the heightened awareness in the trauma bay, diagnosing and treating hemorrhage is a formidable challenge.  

As information is collected about the mechanism of injury, energy transfer, trauma anatomic regions involved, and possible nonhemorrhagic traumatic injuries, the full picture of the patient’s trauma injury burden begins to emerge. While few patients develop hemorrhagic shock, it is incumbent upon the trauma team to quickly recognize it through assessment of vital signs, physical exams, and mechanism of injury. Signs of hemorrhagic shock in the trauma bay include hypotension (SBP less than 90), tachycardia (HR greater than 100), shock index (HR/SBP greater than 1), altered mentation, decreased responsiveness, and poor skin perfusion. If hemorrhagic shock is present, then treatment should follow the four principles of hemorrhagic shock management: 

1. Establish IV access 

2. Transfuse blood 

3. Identify the source of bleeding  

4. Control the bleeding 

Establishing IV access in the hypovolemic patient can be difficult. The most efficient IV access is via antecubital large bore peripheral IVs. If a patient is too hypovolemic to gain IV access, intraosseous access should be established, and resuscitation started. Central venous lines can also be placed in the trauma bay, but the choice of line is important. Long, thin, triple lumen catheters are not ideal for resuscitation as their flow is limited by a small radius and long length. If central venous access is obtained, then a short, wide trauma line catheter should be used. Flow of blood is much easier through a milkshake straw (trauma line) than through a strand of spaghetti (triple lumen catheter).  

Once access is established, blood is transfused. Blood can be transfused as whole blood or in components of red blood cells (RBCs), fresh frozen plasma (FFP), or platelets. When administered as components, transfusions should be balanced in a ratio of 1 unit RBC: 1 unit FFP: 1 pack of platelets. Blood is transfused until the end points of resuscitation are met, typically the resolution of hypotension and altered mentation. Sometimes, injuries may be so severe that a patient will require more than 10 units of RBCs in a 24-hour period, and blood will need to be administered rapidly. In these instances, a Massive Transfusion Protocol (MTP) is initiated in which coolers of blood products with 5 units RBCs, 5 units FFP and 1 pack of platelets are delivered directly to the patient until their resuscitation is complete. The Assessment of Blood Consumption (ABC) score can be used to predict the need for massive transfusion with a score of less than two being unlikely to need massive transfusion.  

Identifying the source of bleeding is difficult in blunt trauma. In penetrating trauma, following the trajectory of the bullet or knife along the trauma anatomic regions allows the trauma team to know what cavity and organs to explore to control the bleeding. In blunt trauma, especially in patients with traumatic brain injuries, it may be difficult to know where the patient is bleeding. As a result, the trauma team assesses the five locations (below) of exsanguination in the trauma bay including the chest with a chest x-ray, the abdomen with a FAST ultrasound, the pelvis with a pelvic x-ray, the thigh based on physical exam and a x-ray of the femur and the environment from an extremity injury.   

Lastly, controlling the bleeding occurs once the exact location or anatomical region of the trauma is identified. Control of bleeding takes place in a variety of forms, including chest tubes and thoracotomy in the chest, laparotomy and interventional radiology-based angioembolization in the abdomen, packing, angioembolization and placement of a binder in the pelvis, traction of the bleeding femur fracture, and tourniquet placement in the bleeding extremity.

Next week, expect a review of two trauma cases using the principles of the last 3 weeks: 1) understanding mechanism of injuries and associated energy transfer, 2) trauma anatomic regions of the torso and retroperitoneum, 3) nonhemorrhagic injury patterns, 4) extremity trauma principles, 5) recognizing hemorrhage and 6) how to treat hemorrhage in the trauma bay. 

All the best,

Joseph Posluszny, MD

July 28, 2025

For the final week of blunt and penetrating trauma, we’ll review two trauma cases that highlight the trauma principles reviewed over the past three weeks. The approach to the trauma patient includes the following questions: 

• What is the mechanism of injury? Amount of energy applied? 

• What are the anatomic zones of injury? 

• Does the patient exhibit signs of hemorrhage? 

• If the patient is hemorrhaging, how can I: 

• Establish IV access? 

• Transfuse blood; Is a massive transfusion protocol (MTP) needed? 

• Identify the source of bleeding? 

• Control the bleeding? 

• Are there other injuries to consider based on the mechanism? 

Case 1: 

EMS reports that a 21-year-old female sustained gunshot wounds to the right chest and right thigh. Upon arrival at the trauma bay, the patient is obtunded with a heart rate of 120 and blood pressure of 70/40. During exposure, the right chest gunshot wound is a few centimeters inferior to the right nipple and along the anterior axillary line (below). The right thigh has an expanding hematoma, and there are no pulses in the right foot. Based on this information, the trauma assessment and treatment includes: 

What is the mechanism of injury? Amount of energy applied? 

Gunshot wounds are high energy mechanisms with a focal trajectory, so major tissue injury in the bullet’s path and bleeding should be anticipated.  

What are the anatomic zones of injury? 

The right chest wound is a right thoracoabdominal wound, which is concerning since the patient may have both intrathoracic and intraabdominal injuries. The list of potential injuries is extensive but includes the lungs, ribs, pulmonary vessels, heart, aorta, IVC, liver, intestines, spleen, and kidneys. In the right lower extremity, the expanding hematoma and lack of distal pulses are concerning for a major arterial injury.  

Does the patient exhibit signs of hemorrhage? 

Yes, the patient is tachycardic, hypotensive and obtunded reflecting decreased perfusion to the brain. This would be considered hemorrhagic shock.  

If the patient is hemorrhaging, how can I: 

Establish IV access? 

Establish two large bore IVs. If this is not possible due to hypovolemia, then intraosseous catheters can be placed for transfusion, or ashort, large bore central venous catheter can also be placed.  

Transfuse blood; Is MTP needed? 

Given the patient’s hemorrhagic shock, emergency blood should be transfused in a balanced 1 unit RBC: 1 unit plasma : 1unit platelet ratio. MTP should be initiated as the extreme vital signs and multiple-compartment, high-energy injuries predict major bleeding.  

Identify the source of bleeding?

Chest x-ray shows a large right hemothorax. The patient’s abdomen is distended and tender. The right thigh has an expanding hematoma, and there is no distal pulse present.  

Control the bleeding?

A chest tube is placed for control of the hemothorax, which improves drainage. A laparotomy is performed, and there is a large liver laceration with extensive bleeding which is controlled with packing. The right femoral artery was injured in the thigh and required a bypass. A right leg fasciotomy was performed to prevent compartment syndrome.

Case 2:

EMS reports a 57-year-old male who fell from a 2-story scaffolding at a construction site. Upon arrival, he awakens to voice but is drowsy. His heart rate is 120, and SBP is 80. His extremities are cool. The patient has difficulty breathing, chest wall tenderness, pelvic tenderness and a right thigh deformity. 

What is the mechanism of injury? Amount of energy applied? 

A fall from 2 stories is a very high energy, blunt mechanism.  

What are the anatomic zones of injury? 

Based on the mechanism and his exam, there may be injuries in the chest, abdomen, pelvis, flank, and/or thigh. 

Does the patient exhibit signs of hemorrhage? 

Yes. The patient is tachycardic, hypotensive, altered and has cool extremities which are all consistent with hemorrhage.  

If the patient is hemorrhaging, how can I:

Establish IV access? 

Peripheral IVs, a large bore central line and/or intraosseous catheters should be established. 

Transfuse blood? 

Blood should be transfused starting in the trauma bay and in a balanced ratio.  

Identify the source of bleeding?

In blunt trauma, the patient can exsanguinate into the chest, abdomen, pelvis, thigh or environment. A chest x-ray shows a large right hemothorax and multiple right rib fractures. A FAST exam of the abdomen is negative for bleeding. A pelvis x-ray shows an open book pelvic fracture. There is a large right thigh hematoma, and an x-ray shows a right femur fracture.  

Control the bleeding?

For the hemothorax, a chest tube is placed with 750 mL of blood output and then the bleeding stops. For the open book pelvic fracture, a pelvic binder is placed, and the pelvis is later repaired in the operating room. For the right femur fracture, the right leg is placed in traction and later repaired.  

We appreciate your attention and hope that the blunt and penetrating trauma education has helped. 

All the best,

Joseph Posluszny, MD