You have a new patient!
A 40-year-old male, a truck driver, is involved in a head-on collision with another vehicle. He has been brought in by ambulance. According to the paramedics, the vehicles were traveling at approximately 85 km/hr, and the patient was restrained by a seatbelt. On arrival at the Emergency Department (ED), the patient is agitated and mildly disoriented. He is tachypneic with a respiratory rate of 30/min, maintaining an O2 saturation of 95% on 12 L/min oxygen via a non-rebreather mask, heart rate of 128 beats/min, blood pressure of 90/52 mmHg, and temperature of 36.1°C. The patient also received 1 L of 0.9% normal saline and 1 unit of O-negative packed red cells in the ambulance. Despite this, his respiratory rate, heart rate, and level of disorientation have worsened.
Emergency Department
In the ED, patients present with a variety of clinical presentations, including both life-threatening and non-life-threatening. Some may have been seen and referred by a clinician before arrival or brought to the department after pre-hospital assessment and care by the emergency medical services (EMS) [1]. Health emergencies affect all age groups and include conditions like acute coronary syndrome, strokes, acute complications of pregnancy, or any chronic illness. Emergency health care providers should respond to these clinically ‘undifferentiated’ patients with symptoms for which the diagnosis may not be known [2]. The root cause of most life-threatening conditions in the ED may be medical or surgical, infection or trauma [2].
In the Emergency Department (ED), there are several potentially life-threatening presentations that demand immediate stabilization. These include trauma, which can result from various forms of accidents or injuries, and shortness of breath, which might indicate critical respiratory distress. An altered mental state also requires prompt attention, as it may signal underlying neurological or systemic issues. Shock, often evidenced by dangerously low blood pressure. Chest pain or discomfort, which could be indicative of a cardiac event, are other urgent concerns. Additionally, cases of poisoning, ingestion of harmful substances, or exposure to toxic materials also necessitate rapid intervention to prevent further harm. Each of these presentations is a medical priority, highlighting the importance of timely and effective response in the ED to ensure patient safety and stability.
These symptoms maybe the only picture that the patients present with, and may constitute the early stage of a critical illness requiring rapid, appropriate intervention and resuscitation, even when the patient seems to appear relatively well [2].
Emergency conditions often require immediate intervention long before a definitive diagnosis is made to stabilize the critically ill patient [3]. Thus, this chapter intends to briefly introduce a basic systematic approach to identifying and managing acute, potentially life-threatening conditions in these patients. This approach will enable all frontline providers, including students, nurses, pre-hospital technicians, and physicians, to manage these patients even in the setting of limited resources [2].
A complete assessment and management of each of the presentations mentioned above is beyond the scope of this chapter. However, the initial approach remains the same, regardless of the patient population or setting [4].
History of the ABCDE approach
The ABC mnemonic’s origins may be traced back to the 1950s. The first two letters of the mnemonic, A and B, resulted from Dr Safar’s description of airway protection techniques and administration of rescue breaths. Kouwenhoven and colleagues later added the letter C to their description of closed-chest cardiac massage [3].
Styner is credited with further developing the Airway, Breathing, Circulation, Disability, and Exposure (ABCDE) approach. After a local aircraft disaster in 1976, Styner and his family were taken to a local healthcare facility, where he saw an insufficiency in the emergency treatment offered. He then founded the Advanced Trauma Life Support course, emphasizing a methodical approach to treating severely injured patients.
The ABCDE approach is universally accepted and utilized by emergency medicine clinicians, technicians, critical care specialists, and traumatologists [3]. Thus, this approach is recommended by international guidelines for suspected serious illness or underlying injury, irrespective of the diagnosis [5]. It is also the first step in post-resuscitation care after the patient achieves return of spontaneous circulation (ROSC) from a cardiac arrest [3]. This systematic approach also aims to improve coordination among the team members and saves time to make critical decisions [3].
The ABCDE approach
Since time is of the essence, the ABCDE method is a systematic approach that can be easily and quickly practiced in the ED. This is incorporated into what is known as ‘Initial patient assessment,’ one of the most crucial steps in evaluation [6]. At each step of this approach, life-threatening problems must be addressed before proceeding to the next assessment step. After the initial assessment, patients must be reassessed regularly to evaluate the treatment response. Anticipate and call for extra help early [7]. Appropriate role allocation and good communication are important for effective team working [7]. Once the patient is stabilized, a secondary survey should be conducted, which includes a thorough history, physical examination, and diagnostic testing [8]. Finally, the tertiary survey is done within 24 hours of presentation to identify any other missed injuries in trauma. Once it is recognized that the patient’s needs exceed the facility’s capabilities, the transfer process must be initiated to an appropriately specialized care center accordingly [8].
Ensure Safe Environment
Before initiating the ABCDE approach, it is essential to ensure both personal safety and a secure environment. This preparation includes addressing any potential risks, such as unexpected or violent behavior, environmental hazards, and the risk of exposure to communicable diseases. Health professionals should consider using appropriate personal protective equipment (PPE) suited to the situation, which may include gloves, gowns, masks, goggles, and thorough hand washing. These precautions are vital to protect both the healthcare provider and the patient, ensuring a safe environment for medical intervention [4].
Initiate First Response
The Resuscitation Council UK (RCUK) (2015) recommends performing a range of initial activities before proceeding with the ABCDE approach [4].
Examine the patient in general (skin color, posture, sensorium, etc.) to determine whether they seem critically ill [4].
After introducing yourself, an initial assessment can be completed in the first 10-15 seconds by asking patients their names and about their active complaints. If they respond normally, it means the airway is patent and brain perfusion is expected [9]. Check for breathing and pulse if the patient appears unconscious or has collapsed. If there is no pulse, call for help and immediately start cardiopulmonary resuscitation (CPR), adhering to local guidelines [9].
Detailed ABCDE Evaluation
Primary Survey
Patients are assessed and prioritized according to their presentations and vital signs. In primary survey, critically ill patients are managed efficiently along with resuscitation. The approach represents the sequence of steps as described below [10]:
A – Airway (with C spine control in Trauma patients)
B – Breathing and Ventilation
C – Circulation (With Hemorrhage control in active bleeding)
D – Disability
E – Exposure / Environment control
A – Airway
Airway obstruction is critical! Gain expert help immediately. If not treated, it can lead to hypoxia, causing damage to the brain, kidneys, and heart, resulting in cardiac arrest and death [4].
Airway management remains the cornerstone of resuscitation and is a specialized skill for the emergency clinician [9].
Assessment of airway patency is the first step. Can the patient talk? If yes, then the airway is patent and not in immediate danger. If not, look for the signs of airway compromise: Noisy breathing, inability to speak, presence of added sounds, stridor or wheezing, choking or gagging, cyanosis, and use of accessory muscles.
The next step is to open the mouth and look for anything obstructing the airway, such as secretions, blood, a foreign body, or mandibular/tracheal/laryngeal fractures [10].
While examining and managing the airway, great care must be taken to restrict excessive movement of the cervical spine and assume the existence of a spinal injury in cases of trauma [11].
Several critical factors can compromise a patient’s airway and must be addressed promptly in emergency settings. A depressed level of consciousness, which may result from conditions such as opioid overdose, head injury, or stroke, can impair airway protection and lead to significant risk [10]. Additionally, an inhaled foreign body, or the presence of blood, vomit, or other secretions, can obstruct the airway and necessitate immediate intervention. Fractures of the facial bones or mandible further complicate airway management due to potential structural damage. Soft tissue swelling, whether caused by anaphylaxis (angioedema) or severe infections like quinsy or necrotizing fasciitis, also seriously threatens the airway. These conditions highlight the importance of vigilant monitoring and rapid response to maintain airway patency and prevent complications.
Intervention: Several basic maneuvers can help maintain a clear airway. Suctioning should be performed if there are any secretions or blood present. Additionally, using the head-tilt, chin-lift, and jaw-thrust maneuvers can aid in keeping the airway open. For patients with a low Glasgow Coma Scale (GCS) score, placing an oropharyngeal or nasopharyngeal airway can be beneficial in maintaining airway patency. It’s also important to inspect the airway for any obvious obstructions; if a visible object is within reach, it may be removed carefully using a finger sweep or suction. It is crucial to remember that assistance from an anesthetist may be required in some cases.
In trauma patients, to protect the C-spine, perform a jaw-thrust rather than a head-tilt chin-lift maneuver and immobilize the C-spine with a cervical collar [9].
A definitive airway, such as endotracheal intubation, may be necessary in patients with airway obstruction, GCS ≤ 8, severe shock or cardiac arrest, and at risk of inhalation injuries [8].
If intubation has failed or is contraindicated, a definitive airway must be established surgically [11].
B – Breathing and Ventilation
Effective ventilation relies on the proper functioning of the lungs, chest wall, and diaphragm, along with a patent airway and sufficient gas exchange to optimize oxygenation [10]. To assess breathing and ventilation, clinicians should evaluate oxygen saturation, monitor the respiratory rate for any signs of abnormality—such as rapid breathing (tachypnea), slow breathing (bradypnea), or shallow breathing (Kussmaul breathing)—and observe for increased work of breathing, such as accessory muscle use, chest retractions, or nasal flaring. Other critical assessments include checking for neck vein distention, examining the position of the trachea, chest expansion, and any injuries or tenderness, as well as auscultating for bilateral air entry and any additional sounds. Chest percussion should be performed to identify dullness, which may indicate hemothorax or effusion, or hyperresonance, suggestive of pneumothorax. Certain pathologies, like tension pneumothorax, massive hemothorax, open pneumothorax, and tracheal or bronchial injuries, can rapidly disrupt ventilation. Other conditions, including simple pneumothorax, pleural effusion, simple hemothorax, rib fractures, flail chest, and pulmonary contusion, may compromise ventilation to a lesser degree [10].
Interventions:
- Oxygen – Ensure all patients are adequately oxygenated, with supplemental oxygen delivered to all severely injured trauma patients [11]. Place them on well-fitted oxygen reservoir masks with a flow rate > 10 L/min, which can then be titrated as needed to maintain adequate saturations. Other means of oxygen delivery (nasal catheter, nasal cannula, non-rebreather) can also be used.
- Bag mask valve ventilation with oxygen – should be given to unconscious patients with abnormal breathing patterns (slow or shallow respiration).
- Other interventions include salbutamol nebulizers, epinephrine, steroids, needle decompression, chest tube insertion, and the use of noninvasive ventilation and pressure support in different clinical scenarios.
C – Circulation (With Hemorrhage control in active bleeding)
Major circulatory compromise in critically ill patients can result from either blood volume loss or reduced cardiac output. In trauma cases, hypotension is assumed to be due to blood loss until proven otherwise. To assess the hemodynamic status, several key evaluations should be performed. These include checking the level of consciousness, as an altered state may indicate impaired cerebral perfusion, and assessing skin perfusion for signs like pallor, cyanosis, mottling, or flushing. Vital signs such as heart rate and blood pressure should be monitored for abnormalities like tachycardia, bradycardia, hypotension, or hypertension. Auscultation can reveal muffled heart sounds, which may suggest cardiac tamponade or pneumothorax, as well as murmurs or a pericardial friction rub that could indicate pericarditis. Checking the extremities for capillary refill and skin temperature is also essential. Additionally, palpation of the abdomen for tenderness or a pulsatile mass may reveal an abdominal aortic aneurysm, while peripheral edema, such as pedal edema, might indicate heart failure.
Interventions:
- Two large-bore IV cannulations must be placed. If this attempt fails, intraosseous access is necessary. Hemorrhagic shock—A definitive control of bleeding along with replacement of intravascular volume is essential. Initial resuscitation should start with warm crystalloids, and blood products should be used. Massive Transfusion Protocol (MTP) should be activated according to local guidelines. In hemorrhagic shock, vasopressors and reversal of anticoagulation (if required) can be considered.
- Hemorrhage control: External hemorrhage can be controlled by direct manual pressure over the site of the wound or tourniquet application.
- In the case of pelvic or femur fractures, placement of pelvic binders or extremity splints may help to stabilize, although definitive management may be surgical or interventional radiological procedures.
- Obstructive shock – Immediate pericardiocentesis for cardiac tamponade, chest tube insertion for tension pneumothorax, and thrombolysis for massive pulmonary embolism.
- Distributive shock – intramuscular epinephrine for anaphylactic shock, empiric antibiotics for sepsis, and hydrocortisone for adrenal crisis.
- Appropriate antihypertensives in hypertensive emergency.
D – Disability
Evaluate neurological status either with AVPU (Alert, Verbal, Pain and Unresponsive) [5] or GCS (Glasgow Coma Scale).
Evaluate for agitation, head and neck trauma, focal neurological signs (seizure, hemiplegia, etc), lateralizing signs, meningeal signs, signs of raised intracranial pressure, and pupillary examination (size and symmetry). Identify any classic toxidromes (sympathomimetic, cholinergic, anticholinergic, opioid, serotonergic, and sedative-hypnotic toxidromes).
| Choose the best response of patient |
|---|
| EYE OPENING |
| 4: Spontaneously |
| 3: To verbal command |
| 2: To pain |
| 1: No response |
| BEST VERBAL RESPONSE |
| 5: Oriented and converses |
| 4: Disoriented and converses |
| 3: Inappropriate words; cries |
| 2: Incomprehensible sounds |
| 1: No response |
| BEST MOTOR RESPONSE |
| 6: Obeys command |
| 5: Localizes pain |
| 4: Flexion withdrawal |
| 3: Flexion abnormal (decorticate) |
| 2: Extension (decerebrate) |
| 1: No response |
The Glasgow Coma Scale (GCS) is a critical tool for assessing the level of consciousness in critically ill patients, providing a score based on eye, verbal, and motor responses. A GCS score ranges from 3 to 15, with lower scores indicating more severe impairment. Scores of 13-15 generally indicate mild impairment, 9-12 suggest moderate impairment, and scores of 8 or below (comatose patient) represent severe impairment and a high risk of poor outcomes. In critically ill patients, a declining GCS score can signal worsening neurological status, potentially due to factors like traumatic brain injury, hypoxia, or systemic deterioration, and often warrants immediate intervention to address underlying causes.
E – Exposure and Environmental control
It is necessary to expose the patient appropriately whilst maintaining dignity and body temperature.
Look at the skin for any signs of trauma (burns, stab wounds, gunshot wounds, etc.), rashes, infected wounds, ulcers, needle track marks, medication patches, implantable devices, tubes, catheters, and stomas; measure core body temperature, and perform logroll (trauma).
Do not forget to check frequently concealed and overlooked areas such as the genital, inguinal, perineal, axilla, back and under dressings [8].
Interventions:
- Use specialized personal protective equipment (PPE), remove all possible triggers such as wet or contaminated clothing, and maintain core body temperature.
- Minimize hypothermia (external rewarming, warm IV fluids) and hyperthermia (surface cooling, cold IV fluids, antipyretics for fever).
Adjuncts to primary survey
1. Electrocardiography (ECG)
2. Pulse oximetry
3. Carbon dioxide (CO2) monitoring
4. Arterial blood gas (ABG) analysis
5. Urinary catheterization (to assess for hematuria and urine output)
6. Gastric catheterization (for decompression)
7. Blood lactate level measurement
8. Chest and pelvis X-rays
9. Extended focused assessment with sonography for trauma (eFAST)
These adjuncts help provide a comprehensive evaluation of the patient’s condition [10].
Secondary Survey
After the initial primary survey and stabilization, proceed to the secondary survey. This includes a detailed history (SAMPLE)and a head-to-toe examination, including reassessment of vital signs, as there is a potential for missing an injury or other findings in an unresponsive patient [10].
The SAMPLE mnemonic is a structured approach for gathering essential patient history in emergency settings. It stands for Signs and Symptoms, Allergies, Medications, Past Medical History, Last Oral Intake, and Events leading to the illness or injury [5].
- “Signs and Symptoms” involves asking the patient, family, or other witnesses about any observable signs or reported symptoms.
“Allergies” are crucial to identify to prevent harm and may help recognize conditions like anaphylaxis. - “Medications” requires a comprehensive list of all current and recent medications, including any changes in dosage.
- “Past Medical History” provides insights into underlying health conditions that may influence the current illness.
- “Last Oral Intake” is important for assessing risks of aspiration or complications if the patient requires sedation or surgery.
- Finally, understanding the “Events” surrounding the illness or injury aids in determining its cause and severity.
Together, these components guide healthcare providers in developing a more accurate and effective treatment plan.
In the secondary survey, a thorough approach is taken to ensure comprehensive care for the patient. This includes performing relevant and appropriate diagnostic tests based on the clinical assessment to confirm diagnoses and guide further treatment. Critical, targeted treatments should be initiated promptly, along with adequate supportive care to stabilize the patient’s condition. If necessary, specialized consults are obtained to address specific medical needs. Additionally, the healthcare team must assess the need for escalation of care or consider an interfacility transfer if the patient requires more specialized resources or advanced care options [8]. This structured approach ensures that all aspects of the patient’s condition are managed effectively.
Adjuncts to secondary survey
Additional x-rays for the spine and extremities, CT scans of the head, chest, abdomen, and spine, urography and angiography with contrast, transesophageal ultrasound, bronchoscopy, and other diagnostics [10].
If the patient starts to deteriorate, immediately go back to the ABCDE approach and reassess!
Special Patient Groups
In recent ATLS updates, the ABCDE approach has been modified to the xABCDEF approach, where “x” stands for eXsanguinating eXternal hemorrhage control and “F” stands for further factors such as special groups (pediatric, Geriatric, and Pregnancy). While the xABCDEF approach is universal and applies to all patient groups, specific anatomic and physiological differences in different populations should be considered while evaluating and treating life-threatening conditions. Some special population groups are discussed here:
Pediatrics [10]
Children have smaller body mass but higher body surface area than their body mass and proportionately larger heads than adults. These characteristics cause children to have increased energy transfer, hypothermia, and blunt brain trauma.
A useful adjunct is the Broselow® Pediatric Emergency Tape, which helps to rapidly identify weight-based medication doses, fluid volumes, and equipment sizes.
The ABCDE approach in children should proceed in the same manner as in adults, bearing in mind the anatomical differences.
Airway – Various anatomical features in children, such as large tissues of the oropharynx (tongue, tonsils), funnel-shaped larynx, more cephalad and anteriorly placed larynx and vocal cords, and shorter length of the trachea, make assessment and management of the airway difficult. Additionally, in smaller children, there is disproportionality in size between the cranium and the midface, making the large occiput in passive flexion of the cervical spine, resulting in the posterior pharynx being displaced anteriorly. The neutral alignment of the spine can be achieved by placing a 1-inch pad below the entire torso of the infant or toddler.
The most preferred technique for orotracheal intubation is under direct vision, along with restriction of the cervical spine, to achieve a definitive airway.
Infants are more prone to bradycardia due to laryngeal stimulation during intubation than older children and adults. Hence, when drug-assisted intubation is required, the administration of atropine sulfate pretreatment must be considered. Atropine also helps to dry out oral secretions, further enhancing the view of landmarks for intubation.
When the airway cannot be maintained by bag-mask ventilation or orotracheal intubation, a rescue airway with either a laryngeal mask airway (LMA), an intubating LMA, or a needle cricothyroidotomy is required.
Red flag signs in children include stridor, excessive drooling, airway swelling, and the child’s unwillingness to move the neck. Examine the airway carefully for any foreign bodies, burns, or obstruction.
Breathing and ventilation – Children’s respiratory rates decrease with age. The normal tidal volumes in infants and children vary from 4-6 ml/kg to 6-8 ml/kg while assisting in ventilation. Care must be taken to limit pressure-related barotrauma during ventilation. It is recommended that children weighing less than 30 kg use a pediatric bag valve mask.
Injuries such as pneumothorax, hemothorax, and hemopneumothorax should be treated by pleural decompression, for tension pneumothorax, and needle decompression in the 2nd intercostal space (over the top of the third rib) at the midclavicular line. The site for chest tube insertion remains the same as in adults.
The most common cause of pediatric cardiac arrest is hypoxia, and the most common acid-base abnormality encountered is respiratory acidosis due to hypoventilation.
Circulation – Important factors in assessing and managing circulation and shock are looking for signs of circulatory compromise, ascertaining the patient’s weight and circulatory volume, gaining timely peripheral venous access, delivering an appropriate volume of fluids with or without blood replacement, evaluating the adequacy of resuscitation, and aiming for thermoregulation.
Children have increased physiological reserves. A 30% decrease in the circulating blood volume may be required for a fall in the systolic blood pressure. Hence, it is important to look for other subtle signs of blood loss, such as progressive weakening of peripheral pulses, narrow pulse pressure to less than 20 mm Hg, skin mottling (in infants and young children), cool extremities, and decreased level of consciousness.
The preferred route is peripheral venous access, but if this is unsuccessful after two attempts, intraosseous access should be obtained.
Fluid resuscitation must be commenced at 20 ml/kg boluses of isotonic crystalloids. If the patient has ongoing bleeding, packed red blood cells may be initiated at 10 ml/kg as soon as possible. Given that children have increased metabolic rates, thinner skin, and lack of substantial subcutaneous tissue, they are prone to develop hypothermia quickly, which may impede a child’s response to treatment, increase coagulation times, and affect the central nervous system (CNS) function. Therefore, overhead lamps, thermal blankets, as well as administration of warm IV fluids, blood products, and inhaled gases may be required during the initial phase of evaluation and resuscitation.
Disability – Hypoglycemia is a very common cause of altered mental state in children, and children can present with altered mental state or seizures. Check for blood glucose in children; if low, administer glucose (IV D10 or D25).
Geriatric [10]
In cases of trauma in geriatric patients, physiological events that may have led to it (e.g., cardiac dysrhythmias) must be considered. A detailed review of long-term medical conditions and medications, along with their effect on vital signs, is necessary. Risk factors for falls include physical impairments, long-term medication use, dementia, and visual, cognitive, or neurological impairments.
Elderly patients are more prone to sustaining burn injuries due to decreased reaction times, hearing and visual impairment, and inability to escape the burning structure. Burn injury remains the cause of significant mortality.
Airway – Due to loss of protective airway reflexes, airway management in the elderly can be challenging and requires a timely decision to establish a life-saving definitive airway. Opening of the mouth and cervical spine maneuvering may be challenging with arthritic changes. Loose dentures should be removed, while well-fitted dentures should be better left inside. Some patients may be edentulous, making intubation easier, but bag-mask ventilation is difficult.
While performing rapid sequence intubation, it is recommended to lower the doses of barbiturates, benzodiazepine, and other sedatives to 20% to 40% to avoid the risk of cardiovascular depression.
Breathing – Elderly patients have decreased compliance of the lungs and the chest wall, which leads to increased breathing work, placing them at a higher risk for respiratory failure. Aging also results in suppressed heart rate during hypoxia, and respiratory failure may present alongside.
Circulation – These patients may have increasing systemic vascular resistance in response to hypovolemia, given that they may have a fixed heart rate and cardiac output. Also, an acceptable blood pressure reading may truly indicate a hypotensive state, as most elderly patients have preexisting hypertension.
A systolic blood pressure of 110 mm Hg is used as a threshold for identifying hypotension in adults over 65.
Several variables, namely base deficit, serum lactate, shock index, and tissue-specific lab markers, can be used to assess for hypoperfusion. Consider early use of advanced monitoring of fluid status, such as central venous pressure (CVP), echocardiography, and bedside ultrasonography, to guide resuscitation.
Disability – Traumatic brain injury is one of the significant complications among the elderly. The dura becomes more adherent to the skull with age, which increases the risk of epidural hematoma. Moreover, these patients are commonly prescribed anticoagulant and antiplatelet medications, which puts these individuals at a higher risk of developing intracranial hemorrhage. Therefore, a very low threshold is indicated for further CT scan imaging in ruling out acute intracranial and spinal pathologies.
Exposure – Increased risk of hypothermia due to loss of subcutaneous fat, nutritional deficiencies, chronic medical illnesses, and therapies. Complications of immobility, such as pressure injuries and delirium, may develop.
Rapid evaluation and relieving from spine boards and cervical collars will help to reduce these injuries.
Pregnant [10]
Evaluation and management of pregnant individuals can be challenging due to the physiological and anatomical changes that affect nearly every organ system in the body. Therefore, knowledge of the physiological and anatomical changes during pregnancy regarding the mother and the fetus is important to provide the best and most appropriate resuscitation and care for both.
The best initial treatment for the fetus is by providing optimal resuscitation of the mother.
Female patients in the reproductive age who present to the ED must be considered pregnant until proven by a definitive pregnancy test or ultrasound exam.
A specialized obstetrician and surgeon should be consulted early in the assessment of pregnant trauma patients; if not available, early transfer to an appropriate facility should be sought.
The uterus is an intrapelvic organ until the 12th week of gestation, around 34 to 36 weeks when it rises to the level of the costal margin. This makes the uterus and its contents more susceptible to blunt abdominal trauma, whereas the bowel remains somewhat preserved. Nevertheless, penetrating upper abdominal trauma in the late gestational period can cause complex intestinal injury due to displacement.
Amniotic fluid embolism and disseminated intravascular coagulation are significant complications of trauma in pregnancy. In the vertex presentation, the fetal head lies in the pelvis, and any fracture of the pelvis can result in fetal skull fracture or intracranial injury.
A sudden decrease in maternal intravascular volume can lead to a profound increase in uterine vascular resistance, thus reducing fetal oxygenation regardless of normal maternal vital signs.
The volume of plasma increases throughout pregnancy and peaks by 34 weeks of gestation. Physiological anemia of pregnancy occurs when there is an increase in red blood cell (RBC) volume, leading to decreased hematocrit levels. In normal, healthy pregnant individuals, blood loss of 1200 to 1500 ml can occur without showing any signs or symptoms of hypovolemia. Nonetheless, this compromise may be seen as fetal distress, indicated by an abnormal fetal heart rate on monitoring.
Leukocytosis is expected during pregnancy, peaking up to 25,000/mm3 during labor. Serum fibrinogen and other clotting factors may be mildly increased, with shorter prothrombin and partial thromboplastin times. However, bleeding and clotting times remain the same.
During late pregnancy, in a supine position, vena cava compression can cause a decrease in cardiac output by 30 % due to lesser venous return from the lower extremities.
In the third trimester of pregnancy, heart rate increases up to 10-15 beats/min than the baseline while assessing for tachycardia in response to hypovolemia. Hypertension, along with proteinuria, indicates the need to manage preeclampsia. Be mindful of eclampsia as a complication during late pregnancy, as its presentation can be similar to a head injury (seizures with hypertension, hyperreflexia, proteinuria, and peripheral edema)
An increase in the tidal volume causes increases in the minute ventilation and hypocapnia (PaCO2 of 30 mm Hg), which is common in the later gestational period. Therefore,
Maintaining adequate arterial oxygenation during resuscitation as oxygen consumption increases during pregnancy is also important.
By the seventh month of gestation, the symphysis pubis widens to about 4 to 8 mm, and sacroiliac joint spaces increase. These alterations must be kept in mind while evaluating pelvic X-ray films during trauma. Additionally, the pelvic vessels that surround the gravid uterus can become engorged, leading to large retroperitoneal hemorrhage after blunt trauma with pelvic fractures.
Every pregnant patient who has sustained major trauma must be admitted with appropriate obstetric and trauma facilities.
Pregnant individuals may present to the ED with non-obstetric causes such as intentional (intimate partner violence, suicide attempt) and unintentional trauma (MVC, fall), and obstetric causes such as ectopic pregnancy, vaginal bleed, contractions, abdominal pain, decreased fetal movement, etc.
“To optimize outcomes for the mother and fetus, assessment and resuscitation of the mother is performed first and then the fetus, before proceeding for secondary survey of the mother.”
Primary Survey - Mother
Airway – Ensure the patient has a patent and maintainable airway with adequate ventilation. In cases where intubation is necessary, maintain appropriate PaCO2 levels according to the patient’s gestational age. Due to the superior displacement of abdominal organs and delayed gastric emptying, there is an increased risk of aspiration during intubation.
Breathing – These patients may have an increased rate of respiration due to pressure effects or hormonal changes. Pulse oximetry and arterial gas must be monitored as adjuncts. It must be remembered that normal maternal bicarbonate levels will be low to compensate for the respiratory alkalosis.
Circulation – Attempt to manually reposition the uterus towards the left side to relieve the pressure on the inferior vena cava and improve the venous return.
Since pregnant individuals have increased intravascular volumes, they can lose a large amount of blood before the onset of tachycardia, hypotension, or other signs of hypovolemia. Therefore, it is essential to remember that the fetus and the placenta are deprived of perfusion, leading to fetal distress while the maternal conditions appear stable.
Administer crystalloid IV fluids and type-specific blood. Vasopressors must be used only as a last resort to raise maternal blood pressure, as these agents can further cause a reduction of the uterine blood flow, leading to fetal hypoxia.
Primary Survey - Fetus
Leading causes of fetal demise include maternal shock and death, followed by placental abruption.
Assess for signs of abruptio placentae (vaginal bleeding, uterine tenderness, frequent uterine contractions, uterine tetany, and irritability). Another rare injury is the uterine rupture (abdominal tenderness, rigidity, guarding or rebound tenderness, abnormal fetal lie, etc.) accompanying hypovolemia and shock.
By 10 weeks of gestation, fetal heart tones can be assessed by Doppler ultrasound, and beyond 20-24 weeks of gestation, continuous fetal monitoring with a tocodynamometer must be performed. At least 6 hours of continuous monitoring in patients with no risk factors for fetal death is recommended, and 24 hours of monitoring in patients with a high risk of fetal death.
Secondary Survey
Perform the secondary survey for non-pregnant individuals, as mentioned.
An obstetrician should ideally examine the perineum, including the pelvis. The presence of amniotic fluid in the vagina, PH greater than 4.5, indicates chorioamniotic membrane rupture.
All pregnant patients with vaginal bleeding, uterine irritability, abdominal tenderness and pain, signs and symptoms of shock, fetal distress, and leakage of amniotic fluid should be admitted for further care.
All pregnant trauma patients with Rh-negative blood group must receive Rh immunoglobulin therapy unless the injury is remote from the uterus within 72 hours of injury.
Obese Patients [10]
In the setting of trauma, procedures such as intubation can be challenging and dangerous due to their anatomy. Diagnostic investigations such as E-FAST, DPL, and CT scans may also be challenging. Moreover, most of these patients have underlying cardiopulmonary diseases, which hinders their ability to compensate for the stress and injury.
Athletes [10]
Owing to their prime conditioning, they may not exhibit early signs such as tachycardia or tachypnea in shock cases. Additionally, they usually have low systolic and diastolic blood pressure.
Revisiting Your Patient
Let’s get back to the patient we discussed earlier and start assessing him:
Airway – The patient maintains his airway but finds breathing hard. Intervention: Apply 15L Oxygen via a nonrebreather mask.
Breathing—A strap mark contusion is seen with multiple bruises. His chest expansion is asymmetrical, with reduced breath sounds on the right side of his chest. There is a dull percussion note on the right lower half of his chest. He maintains oxygen saturation. Intervention: Prepare for chest tube insertion on the right side.
Circulation – Heart sounds are muffled with marked engorgement of the external jugular veins in the neck, a good pulse still palpable in his left radial, but cold clammy extremities. His pulse is 128/min, and his blood pressure is 92/50 mm Hg. Bedside ultrasound FAST (Focused Assessment Sonography in Trauma) shows a pericardial tamponade. Intervention: IV access was gained with two large-bore IV cannulas, blood was drawn for labs, the massive transfusion protocol for blood products was activated, a Foley catheter was inserted to monitor urinary output, and the surgery team was on board to plan for emergent pericardiocentesis.
Disability – Patient’s GCS remains 15, unremarkable pupillary examination and POC glucose is 7 mmol/dl.
Exposure – you notice the strap mark on his chest secondary to his seatbelt restraint, and the multiple bruises. The remaining evaluation is unremarkable, with no head, spine, abdomen, or limb injury.
Adjunct investigations – A portable chest x-ray shows increased cardiac shadow and multiple bilateral rib fractures. There is opacification in the right lung [12].
Discussion
This patient sustained a blunt trauma leading to pericardial tamponade and right-sided hemothorax, leading to hypovolemic shock. The most common cause of shock in a trauma patient is hypovolemic shock due to hemorrhage. However, other types of shock like cardiogenic shock (due to myocardial dysfunction), neurogenic shock (due to sympathetic dysfunction), or obstructive shock (due to tension pneumothorax, obstruction of great vessels) can occur.
Early signs of shock include tachycardia, which is the body’s attempt to preserve cardiac output and cool peripheries, and reduced capillary refill time caused by peripheral vasoconstriction. This is caused by the release of catecholamine and vasoactive hormone, which leads to increased diastolic blood pressure and reduced pulse pressure. For this reason, measuring pulse pressure rather than systolic blood pressure allows earlier detection of hypovolaemic shock, as the body can lose up to 30% of its blood volume before a drop in systolic blood pressure is appreciated.
Initiate fluid resuscitation in these patients and do not wait for them to develop hypotension.
The main aim is to maintain organ perfusion and tissue oxygenation. In children, start with crystalloid fluid boluses of 20 ml/kg, and in adults, an initial 1 L can be given. In patients who have sustained a major blood loss, consider initiating the Massive Transfusion Protocol (MTP) for blood products as soon as possible.
A few current trauma guidelines have recommended ‘permissive hypotension’ or ‘balanced resuscitation,’ where the principle is to stabilize any blood clots that may have been formed, and aggressive blood pressure resuscitation may disrupt this ‘first formed clot’ and may contribute to further hemorrhage.
To evaluate response to fluid resuscitation, assess the level of consciousness, improvement in tachycardia, skin temperature, capillary refill, and urine output (>0.5 ml/kg/hour in adults).
Besides administering packed red blood cells, do not forget to transfuse platelets, fresh frozen plasma, or cryoprecipitate, as large blood loss can develop coagulopathy in 30% of these injured patients. Tranexamic acid (TXA), an antifibrinolytic, can be utilized in addition as a 1 g bolus over 10 minutes followed by 1 g over 8 hours within 3 hours of trauma without an increased risk of thromboembolic events [11].
This systematic approach focuses on identifying and treating this hemorrhagic shock case. Bedside adjuncts such as FAST examination and portable chest X-ray can provide valuable clues to the cause of shock. A trauma CT scan is only performed once the patient is stable enough to go to the scan room.
This patient’s vital signs improve slightly but remain unstable, and blood is kept draining into the chest drain. The patient is taken to the operation theatre for an emergency thoracotomy [12].
Authors
Roxanne R. Maria
Hamid A. Chatha
Listen to the chapter
References
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Reviewed By
Arif Alper Cevik, MD, FEMAT, FIFEM
Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.
