Overview
Definition
Blunt abdominal injury is defined as damage to the abdomen and/or abdominal organs secondary to impact with a blunt (not penetrating) object or surface.
Epidemiology and etiology
- Blunt abdominal injuries make up 80% of all abdominal injuries presenting to emergency departments in the United States.
- Causes:
- Most commonly caused by a motor vehicle collision (MVC)
- Blows to abdomen and falls are also common causes.
- Most commonly injured organs: spleen Spleen The spleen is the largest lymphoid organ in the body, located in the LUQ of the abdomen, superior to the left kidney and posterior to the stomach at the level of the 9th-11th ribs just below the diaphragm. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes. Spleen and liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver
Anatomy
- Peritoneal cavity:
- Subdivided into intrathoracic and abdominal segments
- Intrathoracic segment includes:
- Diaphragm Diaphragm The diaphragm is a large, dome-shaped muscle that separates the thoracic cavity from the abdominal cavity. The diaphragm consists of muscle fibers and a large central tendon, which is divided into right and left parts. As the primary muscle of inspiration, the diaphragm contributes 75% of the total inspiratory muscle force. Diaphragm
- Liver
- Spleen
- Stomach Stomach The stomach is a muscular sac in the upper left portion of the abdomen that plays a critical role in digestion. The stomach develops from the foregut and connects the esophagus with the duodenum. Structurally, the stomach is C-shaped and forms a greater and lesser curvature and is divided grossly into regions: the cardia, fundus, body, and pylorus. Stomach
- Transverse colon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix
- Retroperitoneum:
- Hard to access on physical exam and peritoneal lavage
- Contains:
- Aorta
- Vena cava
- Pancreas Pancreas The pancreas lies mostly posterior to the stomach and extends across the posterior abdominal wall from the duodenum on the right to the spleen on the left. This organ has both exocrine and endocrine tissue. Pancreas
- Kidney
- Ureters
- Portions of the duodenum and colon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix
- Pelvic compartment: contains pelvic organs (bladder, uterus/ ovaries Ovaries Ovaries are the paired gonads of the female reproductive system that contain haploid gametes known as oocytes. The ovaries are located intraperitoneally in the pelvis, just posterior to the broad ligament, and are connected to the pelvic sidewall and to the uterus by ligaments. These organs function to secrete hormones (estrogen and progesterone) and to produce the female germ cells (oocytes). Ovaries, or prostate Prostate The prostate is a gland in the male reproductive system. The gland surrounds the bladder neck and a portion of the urethra. The prostate is an exocrine gland that produces a weakly acidic secretion, which accounts for roughly 20% of the seminal fluid. Prostate and other Male Reproductive Glands)
Intra-abdominal organs:
Image: “Anatomy of the human abdomen” by Tvanbr. License: Public domain.
The abdomen contains many organs that may become injured in the setting of blunt trauma. Most commonly, the liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver and spleen Spleen The spleen is the largest lymphoid organ in the body, located in the LUQ of the abdomen, superior to the left kidney and posterior to the stomach at the level of the 9th-11th ribs just below the diaphragm. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes. Spleen are injured.
Retroperitoneal organs:
Image: “Viscera and large vessels” by Henry Vandyke Carter. License: Public domain.
Organs in the retroperitoneal space include the kidneys Kidneys The kidneys are a pair of bean-shaped organs located retroperitoneally against the posterior wall of the abdomen on either side of the spine. As part of the urinary tract, the kidneys are responsible for blood filtration and excretion of water-soluble waste in the urine. Kidneys and ureters, and portions of the duodenum, colon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix, aorta, vena cava, and pancreas.
Pathophysiology
Blunt abdominal trauma can occur due to several pathologic processes:
- Deceleration:
- Shear forces cause organs and vasculature to tear from their points of attachment to the peritoneum Peritoneum The peritoneum is a serous membrane lining the abdominopelvic cavity. This lining is formed by connective tissue and originates from the mesoderm. The membrane lines both the abdominal walls (as parietal peritoneum) and all of the visceral organs (as visceral peritoneum). Peritoneum and Retroperitoneum.
- Kidneys are the most vulnerable.
- Crushing:
- Anterior forces trap organs between the anterior abdominal wall Anterior abdominal wall The anterior abdominal wall is anatomically delineated as a hexagonal area defined superiorly by the xiphoid process, laterally by the midaxillary lines, and inferiorly by the pubic symphysis. Anterior Abdominal Wall and the posterior thoracic cage.
- Solid organs are sensitive to the crushing mechanism of injury.
- External compression:
- A direct blow or external compression against a rigid fixed structure
- Hollow organs are more vulnerable due to sudden ↑ in intra-abdominal pressure
Diagnosis
Because of the wide variety and severity of injuries associated with blunt abdominal trauma, a prompt but careful history and physical exam are necessary to direct investigation with imaging studies.
History
- Mechanism of trauma:
- May suggest severity of injury
- MVC:
- Position seated in the car
- Other fatalities in the car
- Amount of intrusion into the car (> 6 inches predicts serious injury)
- History of previous trauma
- Drug (illicit and prescription) or alcohol use by the patient
- Last thing the patient had to eat or drink: important for intubation/ anesthesia Anesthesia Anesthesiology is the field of medicine that focuses on interventions that bring a state of anesthesia upon an individual. General anesthesia is characterized by a reversible loss of consciousness along with analgesia, amnesia, and muscle relaxation. Anesthesiology: History and Basic Concepts consideration
- Prior surgical history
Physical exam
- Airway, breathing, circulation (ABC) assessment:
- Airway:
- Look for foreign objects blocking airway (loose teeth Teeth Normally, an adult has 32 teeth: 16 maxillary and 16 mandibular. These teeth are divided into 4 quadrants with 8 teeth each. Each quadrant consists of 2 incisors (dentes incisivi), 1 canine (dens caninus), 2 premolars (dentes premolares), and 3 molars (dentes molares). Teeth are composed of enamel, dentin, and dental cement. Teeth are common foreign bodies in high-force trauma).
- Assess for injury to the trachea Trachea The trachea is a tubular structure that forms part of the lower respiratory tract. The trachea is continuous superiorly with the larynx and inferiorly becomes the bronchial tree within the lungs. The trachea consists of a support frame of semicircular, or C-shaped, rings made out of hyaline cartilage and reinforced by collagenous connective tissue. Trachea (tracheal injury means intubation will be complex).
- Listen for unusual breathing sounds (stridor suggests narrowing by a foreign body or edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema).
- Breathing:
- Look at chest wall Chest wall The chest wall consists of skin, fat, muscles, bones, and cartilage. The bony structure of the chest wall is composed of the ribs, sternum, and thoracic vertebrae. The chest wall serves as armor for the vital intrathoracic organs and provides the stability necessary for the movement of the shoulders and arms. Chest Wall movement for even and spontaneous breathing (uneven chest movement suggests “ flail chest Flail chest Flail chest is a life-threatening traumatic injury that occurs when 3 or more contiguous ribs are fractured in 2 or more different locations. Patients present with chest pain, tachypnea, hypoxia, and paradoxical chest wall movement. Flail Chest”).
- Listen to breath sounds (muffled or uneven may suggest pneumothorax Pneumothorax A pneumothorax is a life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. A pneumothorax can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain, dyspnea, and diminished breath sounds on exam. Pneumothorax or hemothorax Hemothorax A hemothorax is a collection of blood in the pleural cavity. Hemothorax most commonly occurs due to damage to the intercostal arteries or from a lung laceration following chest trauma. Hemothorax can also occur as a complication of disease, or hemothorax may be spontaneous or iatrogenic. Hemothorax).
- Circulation:
- Palpate pulses on all 4 extremities (tachycardia suggests hemodynamic instability or pneumothorax Pneumothorax A pneumothorax is a life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. A pneumothorax can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain, dyspnea, and diminished breath sounds on exam. Pneumothorax).
- Assess capillary refill on extremities.
- Airway:
- Secondary survey:
- Examine patient head to toe.
- Base imaging decision on exam findings.
- External injury should prompt investigation for corresponding internal injury.
- If the patient is alert and free from distracting
pain
Pain
Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care.
Physiology of Pain, the most specific symptoms of blunt abdominal trauma are:
- Abdominal pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain
- Abdominal tenderness
- Peritoneal findings
- Signs concerning for severe intra-abdominal injury:
- Seat belt sign
- Hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension
- Rebound tenderness
- Abdominal distention
- Abdominal guarding
- Concomitant femur fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures
Imaging studies
- FAST (focused assessment with sonography for trauma): used in all patients (stable or unstable) to look for intraperitoneal blood and
pericardial effusion
Pericardial effusion
Pericardial effusion is the accumulation of excess fluid in the pericardial space around the heart. The pericardium does not easily expand; thus, rapid fluid accumulation leads to increased pressure around the heart. The increase in pressure restricts cardiac filling, resulting in decreased cardiac output and cardiac tamponade.
Pericardial Effusion and Cardiac Tamponade:
- Hemodynamically unstable patients:
- Positive FAST → emergent laparotomy Laparotomy Laparotomy is an open surgical exploration of the abdomen, usually through a single large incision. Laparotomy and Laparoscopy
- Negative FAST → search for extra-abdominal bleeding sources (femur fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures)
- Equivocal FAST → diagnostic peritoneal lavage (DPL) or stabilize patient and computed tomography (CT) scan
- Hemodynamically stable patients:
- Positive FAST → emergent laparotomy Laparotomy Laparotomy is an open surgical exploration of the abdomen, usually through a single large incision. Laparotomy and Laparoscopy
- Negative FAST, low risk for intra-abdominal injury → observation
- Negative or equivocal FAST with high risk for intra-abdominal injury → CT scan
- Hemodynamically unstable patients:
- X-ray: directed by exam findings:
- Chest X-ray: can show free intraperitoneal air, herniation of abdominal contents
- Pelvic X-ray: Pelvic bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Structure of Bones fractures can be a source of bleeding or bladder injury.
- CT scan abdomen with contrast:
- Imaging of choice for stable patients
- Provides information regarding retroperitoneal structures, diaphragm, and solid abdominal organs
Other diagnostic studies
- Hematocrit:
- < 30% suggestive of intra-abdominal injury
- Normal hematocrit does not rule out severe injury.
- Urinalysis: Blood is suggestive of serious renal injury.
- Liver function tests Liver function tests Liver function tests, also known as hepatic function panels, are one of the most commonly performed screening blood tests. Such tests are also used to detect, evaluate, and monitor acute and chronic liver diseases. Liver Function Tests
- DPL:
- Invasive procedure used to evaluate the presence of blood in the abdominal cavity: A catheter is put into the peritoneal cavity and fluid is aspirated and evaluated.
- Not often used: alternative when CT scan and FAST are not available
Features of abdominal injuries by organ
| Injured organ | Features |
|---|---|
| Duodenum |
|
| Spleen |
|
| Liver |
|
| Pelvis |
|
| Kidney |
|
Management
Careful investigation will yield evidence of injured organs, directing further management.
| Injured organ | Management |
|---|---|
| Duodenum |
|
| Spleen |
|
| Liver |
|
| Pelvis |
|
| Kidney |
|
Clinical Relevance
- Penetrating abdominal injury Penetrating abdominal injury Penetrating abdominal injuries are created by an object puncturing the abdominal wall. Injuries can be high velocity, like gunshot wounds, or low velocity, like stab wounds. Different structures can be injured, including the duodenum, spleen, liver, kidneys, and pelvic organs. Penetrating Abdominal Injury: typically involves the violation of the abdominal cavity by a gunshot wound or stab wound. Most commonly injured structures are small bowels, followed by the colon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix, liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver, and vascular structures. Treatment is exploratory laparotomy Laparotomy Laparotomy is an open surgical exploration of the abdomen, usually through a single large incision. Laparotomy and Laparoscopy.
- Splenic injury: In blunt injuries, the liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver and spleen Spleen The spleen is the largest lymphoid organ in the body, located in the LUQ of the abdomen, superior to the left kidney and posterior to the stomach at the level of the 9th-11th ribs just below the diaphragm. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes. Spleen are the most commonly injured organs. Usually, splenic injury is associated with lower-left rib fractures. Features of splenic injury include hypotension, tachycardia, abdominal pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain, left chest wall Chest wall The chest wall consists of skin, fat, muscles, bones, and cartilage. The bony structure of the chest wall is composed of the ribs, sternum, and thoracic vertebrae. The chest wall serves as armor for the vital intrathoracic organs and provides the stability necessary for the movement of the shoulders and arms. Chest Wall pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain, and left shoulder pain Shoulder Pain Acute shoulder injuries are a common reason for visits to primary care physicians and EDs. Common acute shoulder injuries include acromioclavicular joint injuries, clavicle fractures, glenohumeral dislocations, proximal humerus fractures, and rotator cuff tears. Acute Shoulder Pain (referred pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain due to phrenic nerve irritation from splenic hemorrhage).
- Pelvic injury: Pelvic injuries and pelvic fractures Pelvic Fractures Pelvic fractures are a disruption in the cortex of a pelvic bone involving iliac wing fractures, acetabular fractures, or those causing loss of integrity of the pelvic ring (the sacrum and the 2 innominate bones). Patients often present with a history of trauma or a fall, limb length discrepancy, intense pain on palpation, and mechanical instability. Pelvic Fractures are among the worst complications of blunt abdominal injuries. Clinical features include hypotension, pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain with movement, gross hematuria, and peri-pelvic ecchymoses. A digital rectal examination is important to identify injury to the rectum Rectum The rectum and anal canal are the most terminal parts of the lower GI tract/large intestine that form a functional unit and control defecation. Fecal continence is maintained by several important anatomic structures including rectal folds, anal valves, the sling-like puborectalis muscle, and internal and external anal sphincters. Rectum and Anal Canal and locate the prostate Prostate The prostate is a gland in the male reproductive system. The gland surrounds the bladder neck and a portion of the urethra. The prostate is an exocrine gland that produces a weakly acidic secretion, which accounts for roughly 20% of the seminal fluid. Prostate and other Male Reproductive Glands. Treatment is usually limited to supportive care, but surgical stabilization may sometimes be necessary.
- ABC assessment: The ABC assessment is an approach to managing critically ill patients. Airway, breathing, and circulation is the essential 1st step to perform when encountering a patient. The steps are easily adaptive to many situations, including unresponsive patients, cardiac arrests, and critical medical or trauma patients. For trauma patients, ABC includes the primary survey, the initial evaluation, and management of injuries.
References
- Nishijima DK, Simel DL, Wisner DH, & Holmes JF. (2012). Does this adult patient have a blunt intra-abdominal injury? JAMA. Apr 11;307(14):1517-27. doi: 10.1001/jama.2012.422. PMID: 22496266; PMCID: PMC4966670.
- Isenhour JL, & Marx J. (2007). Advances in abdominal trauma. Emerg Med Clin North Am. Aug;25(3):713-33, ix. doi: 10.1016/j.emc.2007.06.002. PMID: 17826214.
- Newgard CD, Lewis RJ, & Jolly BT. (2002). Use of out-of-hospital variables to predict severity of injury in pediatric patients involved in motor vehicle crashes. Ann Emerg Med. May;39(5):481-91. doi: 10.1067/mem.2002.123549. PMID: 11973555.
- Rivara FP, Koepsell TD, Grossman DC, & Mock C. (2000). Effectiveness of automatic shoulder belt systems in motor vehicle crashes. JAMA. Jun 7;283(21):2826-8. doi: 10.1001/jama.283.21.2826. PMID: 10838652.
- Nishijima DK, Simel DL, Wisner DH, & Holmes JF. (2012). Does this adult patient have a blunt intra-abdominal injury? JAMA. Apr 11;307(14):1517-27. doi: 10.1001/jama.2012.422. PMID: 22496266; PMCID: PMC4966670
