The Primary Survey: A Systematic Approach to the Critically Injured Patient
Definition
The primary survey is a rapid, systematic process for the immediate assessment and management of life-threatening injuries in a trauma patient. It is guided by the <C>ABCDE mnemonic, a framework that prioritizes interventions based on their potential to cause immediate death. This is not a passive checklist, but a dynamic, iterative cycle of assessment, intervention, and reassessment designed to "treat first what kills first" (2, 3). In the chaotic environment of a trauma resuscitation, this structured approach acts as a crucial cognitive tool, preventing fixation errors and ensuring that the most critical threats are addressed in a logical sequence.
Epidemiology
Trauma remains a significant cause of morbidity and mortality in Malaysia and is a major burden on the healthcare system. Road traffic incidents are the leading cause, accounting for a majority of trauma-related deaths, particularly among motorcyclists, who represent a high-risk, vulnerable group (1). According to the Department of Statistics Malaysia, road transport accidents were the fourth leading cause of death in 2022 and the principal cause of death for the 15-40 age group (2). This underscores the critical importance for all Malaysian clinicians, from house officers to specialists, to be proficient in the initial management of the critically injured patient. Globally, trauma is a leading cause of death and disability in people under 45, making proficiency in the primary survey a core competency for any acute care provider (3).
When do we do this
The primary survey is initiated for any patient who has sustained significant physical trauma, which can be broadly categorized. Understanding the mechanism of injury is crucial as it helps predict injury patterns.
Blunt Trauma: This is the most common form in Malaysia, resulting from energy transfer without penetration of the skin. It includes:
Road Traffic Accidents: High-speed incidents involving cars, and especially motorcycles, often result in multi-system trauma, including head injuries, solid organ lacerations (spleen, liver), and pelvic ring fractures.
Falls from Height: The pattern of injury depends on the height and landing surface, but commonly includes axial skeleton fractures (spine, pelvis) and calcaneal fractures.
Assaults: Often result in facial fractures, head injuries, and torso trauma.
Penetrating Trauma: Less common but often more predictable in its injury pattern. It includes:
Stab Wounds: Low-energy injuries where damage is confined to the path of the object.
Gunshot Wounds: High-energy injuries that cause significant damage not only along the bullet tract but also from the cavitation effect, leading to widespread tissue destruction.
Burns and Inhalation Injuries: These present the dual threat of cutaneous injury and systemic effects, with a particular risk of airway compromise from edema.
The Idea
The logic of the primary survey sequence is dictated by the physiology of immediate death from trauma. The framework prioritizes interventions based on the speed at which a condition can kill a patient. The entire process is designed to combat the "Trauma Triad of Death": hypothermia, metabolic acidosis, and coagulopathy. This is a vicious and self-propagating cycle that is a primary driver of mortality in exsanguinating patients (4).
Hypothermia: A core temperature <35°C directly impairs the function of coagulation enzymes and platelet activity, preventing effective clot formation.
Acidosis: Tissue hypoperfusion from blood loss leads to anaerobic metabolism and lactic acid production. An acidic environment further denatures clotting factors and enzymes, worsening coagulopathy.
Coagulopathy: The inability to form clots, caused by both hypothermia and acidosis, as well as the consumption and dilution of clotting factors, leads to more bleeding. This ongoing hemorrhage worsens hypoperfusion (and thus acidosis) and requires infusion of more fluids, which are often cold (worsening hypothermia).
The modern <C>ABCDE approach prioritizes catastrophic external hemorrhage over airway management. This reflects the stark physiological reality that a patient can exsanguinate from a major arterial bleed in as little as 2-3 minutes, a timeframe that is often shorter than that required to secure a difficult airway. Without circulating volume to carry oxygen, a patent airway is futile (5).
The Primary Survey: A Step-by-Step Clinical Guide
<C> - Catastrophic Hemorrhage
This step precedes all others and must be performed in the first 10 seconds. It is a rapid "from the doorway" visual assessment for evidence of massive, life-threatening external bleeding. Look for pulsatile arterial bleeding, significant pooling of blood on the stretcher, or blood-saturated clothing.
Action: Immediately apply firm, direct manual pressure to the wound using gauze or a dressing. This is the first and most fundamental intervention (6).
High-Yield Action: For life-threatening limb hemorrhage not controlled by direct pressure, apply a commercial tourniquet "high and tight" on the limb and tighten until bleeding stops and the distal pulse is absent. Document the time of application on the tourniquet and in the patient's notes. This is a life-saving, non-negotiable step (7).
Action: For junctional hemorrhage (in the groin, buttocks, or axilla where a tourniquet cannot be placed), pack the wound tightly with hemostatic gauze. The aim is to push the gauze directly onto the source of bleeding deep within the wound, followed by at least three minutes of sustained, firm direct pressure (8).
A - Airway with Cervical Spine Protection
Crucial Point: Assume every patient with a significant mechanism of injury, particularly blunt trauma above the clavicles or an altered level of consciousness, has an unstable cervical spine injury until it is definitively cleared. One provider must be dedicated to maintaining Manual In-Line Stabilisation (MILS) and should not be distracted by other tasks (9).
Assessment:
Talk Test: Ask the patient their name. A normal, clear verbal response in a normal tone of voice provides a wealth of information: the airway is patent, ventilation is sufficient to generate speech, and cerebral perfusion is adequate to support consciousness (3).
Look: Open the mouth and look for any foreign bodies (blood, vomit, secretions, dislodged teeth), which must be removed with suction. Look for facial trauma, burns, or neck hematomas that could signal impending airway obstruction (9).
Listen: Listen for abnormal airway sounds. Stridor is a high-pitched inspiratory sound indicating critical upper airway narrowing and is a pre-terminal sign. Gurgling indicates fluid in the upper airway requiring immediate suctioning. Snoring suggests mechanical obstruction by the tongue. Hoarseness may indicate laryngeal trauma (3).
Interventions:
Jaw Thrust: This is the mandatory initial maneuver to open the airway in any patient with a suspected cervical spine injury (the action), as it lifts the tongue off the posterior pharynx without extending the neck and potentially worsening a spinal injury (the rationale) (9). The head-tilt chin-lift is strictly contraindicated.
Oropharyngeal Airway (OPA): This J-shaped device should only be used in a deeply unconscious patient who lacks a gag reflex. Its placement in a patient with an intact reflex will induce vomiting and aspiration (10).
Nasopharyngeal Airway (NPA): A soft, flexible tube that is well-tolerated by conscious or semi-conscious patients. It is relatively contraindicated with suspected basilar skull fractures due to the small risk of intracranial passage (10).
Definitive Airway (Intubation): This is indicated for a GCS score of ≤ 8, inability to maintain airway patency by other means, or evidence of impending airway obstruction (e.g., expanding neck hematoma, inhalation injury, subcutaneous emphysema in the neck). In trauma, this is typically performed via Rapid Sequence Intubation (RSI) by the most experienced provider available (9).
B - Breathing and Ventilation
Once a patent airway is established, the next priority is to ensure that the patient's breathing is adequate to support oxygenation and ventilation. Expose the chest fully, front and back.
Assessment:
Inspect: Observe the respiratory rate, depth, and effort. Note any accessory muscle use or nasal flaring. Look for asymmetry of chest wall excursion and any paradoxical chest wall movement, which is the hallmark of a flail chest (11).
Palpate: Gently palpate the entire chest cage, including the clavicles, sternum, and each rib, for tenderness, instability, or bony crepitus. Specifically feel for subcutaneous emphysema (air in the soft tissues, which feels like "Rice Krispies"), as it indicates a pneumothorax or tracheobronchial injury (11).
Percussion: While difficult in a loud trauma bay, percussion can be useful. Hyper-resonance to percussion suggests air in the pleural space (pneumothorax), whereas dullness suggests fluid (hemothorax) (11).
Auscultate: Listen with a stethoscope high on the anterior chest (apices) and at the bases in the axillae for the presence and equality of breath sounds. Unilaterally absent or diminished breath sounds are a critical finding highly suggestive of a pneumothorax or hemothorax (11).
Management of the "Lethal Six" Thoracic Injuries:
Tension Pneumothorax: This is a clinical diagnosis (severe respiratory distress, hypotension, tachycardia, unilaterally absent breath sounds, jugular venous distension). Do not wait for an X-ray. Perform immediate needle decompression or, preferably, finger thoracostomy in the 4th or 5th intercostal space, just anterior to the mid-axillary line (the action). This relieves the pressure on the heart and great vessels, treating the obstructive shock (the rationale) (12).
Open Pneumothorax ("Sucking Chest Wound"): This occurs when a large chest wall defect allows air to be preferentially drawn into the pleural space. Apply a sterile, three-sided occlusive dressing (the action). This creates a one-way flutter valve that allows trapped air to exit the pleural space during expiration but prevents air from entering during inspiration (the rationale) (13).
Massive Hemothorax: Defined as >1500mL of blood in a single hemithorax. The patient presents with signs of shock (hypotension, tachycardia) combined with unilaterally absent breath sounds and dullness to percussion. Crucially, the neck veins are typically flat due to severe hypovolemia. Treatment involves two simultaneous actions: 1) restoration of blood volume with aggressive hemostatic resuscitation, and 2) drainage of the chest with a large-bore (32-40 French) chest tube (the action) to allow for lung re-expansion (the rationale) (14).
Flail Chest: Occurs when a segment of the chest wall loses bony continuity. It is characterized by paradoxical movement. However, the most significant life threat is not the paradoxical motion itself, but the severe underlying pulmonary contusion (bruising of the lung tissue) that almost always accompanies it. This contusion causes hypoxia. Management is therefore focused on providing high-flow oxygen, aggressive pain control (e.g., nerve blocks), and respiratory support, often requiring positive pressure ventilation (11).
Cardiac Tamponade: Most common with penetrating trauma to the "cardiac box." Blood accumulates in the pericardial sac, restricting heart function and causing obstructive shock. The diagnosis is most reliably made at the bedside with an eFAST ultrasound, which will show pericardial fluid. The immediate, temporizing intervention is pericardiocentesis, but definitive treatment is surgical repair (15).
C - Circulation and Hemorrhage Control
In any trauma patient, shock is considered to be hemorrhagic in origin until proven otherwise. A critical principle is that hypotension is a late and ominous sign of decompensated shock. The primary survey must be attuned to the more subtle signs of compensated shock to allow for intervention before irreversible organ damage occurs.
Assessment for Signs of Hypoperfusion:
Level of Consciousness: As perfusion to the brain decreases, the patient may become anxious, agitated, confused, or lethargic. An altered mental status in the absence of a head injury is a highly reliable sign of shock (3).
Skin: Peripheral vasoconstriction shunts blood away from the skin to the core. This results in skin that is cool to the touch, pale or ashen in color, and clammy or diaphoretic (3).
Pulse: Tachycardia is one of the earliest compensatory mechanisms. A rapid (>100 bpm in an adult) and thready (weak) pulse is a classic sign of hypovolemic shock. Be aware that elderly patients on beta-blockers may not mount a tachycardic response (3).
Capillary Refill: The time it takes for color to return to a nail bed after applying pressure. A refill time of more than 2 seconds is abnormal and suggests poor peripheral perfusion (3).
Identifying the Source of Bleeding ("Blood on the floor and four more"): Once shock is identified, rapidly search for the source.
External: Re-evaluate for any missed external hemorrhage (<C>).
Chest: Assessed with exam and chest X-ray/eFAST.
Abdomen: The physical exam is unreliable. The eFAST scan is critical for detecting free fluid (hemoperitoneum).
Pelvis: High-energy fractures can cause massive retroperitoneal hemorrhage. Assess for stability with gentle compression. If unstable, do not rock the pelvis, as this can dislodge clots.
Long Bones: A closed femur fracture can result in the loss of 1 to 1.5 liters of blood into the thigh compartment (3).
Interventions:
Vascular Access: The standard of care is to establish two large-bore (16-gauge or larger) peripheral IV catheters, preferably in the antecubital fossae. If peripheral access cannot be obtained rapidly (e.g., within 90 seconds), move immediately to Intraosseous (IO) access. An IO needle provides rapid access to the non-collapsible venous plexus within bone marrow (16).
Pelvic Binder: In any patient with a high-risk mechanism for pelvic fracture and hemodynamic instability, a pelvic binder should be applied immediately at the level of the greater trochanters (the action). This non-invasive device reduces the volume of the pelvic ring, which helps to tamponade venous bleeding and stabilize fracture fragments (the rationale) (16).
Hemostatic Resuscitation: This modern approach aims to combat the lethal triad.
Limit Crystalloids: Aggressively avoid large volumes of normal saline or other crystalloids. This practice is now known to be harmful as it worsens acidosis, induces a dilutional coagulopathy, and exacerbates hypothermia (17).
Give Blood Products Early: For patients in hemorrhagic shock or those requiring massive transfusion, the focus is on the early administration of packed red blood cells (pRBCs), fresh frozen plasma (FFP), and platelets in a balanced ratio, typically 1:1:1. This ratio approximates whole blood and provides clotting factors and platelets along with oxygen-carrying capacity, directly treating the underlying coagulopathy (17).
Tranexamic Acid (TXA): This antifibrinolytic agent helps to stabilize clots that have formed. Evidence from the CRASH-2 trial shows that administering TXA within 3 hours of injury to patients with or at risk of significant hemorrhage reduces mortality. Give a 1-gram bolus over 10 minutes, followed by a 1-gram infusion over 8 hours (the action) as it stabilizes clots and reduces mortality from bleeding (the rationale) (18).
D - Disability (Neurological Status)
The 'Disability' component is a brief, focused neurological examination designed to establish the patient's baseline level of consciousness and identify evidence of severe intracranial or spinal cord injury. A decline in neurological status can be from a primary brain injury or from secondary insults like hypoxia or hypotension.
Assessment:
GCS: Calculate the Glasgow Coma Scale (Eye, Verbal, Motor response). It is crucial to document the individual components (e.g., E2 V3 M4) rather than just the total score, as this provides more detailed information for tracking changes. A GCS of ≤ 8 is defined as a severe brain injury and is a strong indication for definitive airway management (intubation) (19).
Pupils: Assess the size (in millimeters), symmetry, and reactivity of both pupils to a bright light. A unilateral fixed and dilated pupil (a "blown pupil") in a patient with a decreased level of consciousness is a classic and ominous sign of uncal herniation compressing the oculomotor nerve (CN III). This is a neurosurgical emergency (19).
Blood Glucose: A rapid, point-of-care blood glucose test is an essential part of the 'Disability' assessment for any patient with an altered mental status. Hypoglycemia can perfectly mimic the signs of a traumatic brain injury and is a rapidly reversible cause of neurological dysfunction. Failure to check is a critical omission (19).
E - Exposure and Environment
The final step encompasses two competing priorities: the complete physical exposure of the patient to identify all injuries, and the simultaneous control of the environment to prevent iatrogenic hypothermia.
Exposure: To conduct a thorough assessment, the patient's clothing must be completely removed, usually by cutting it away to avoid manipulating potentially fractured limbs or an unstable spine. It is critical to inspect the patient's entire skin surface, paying special attention to areas that are frequently overlooked: the back, buttocks, perineum, axillae, and posterior scalp (20).
Log Roll: To examine the posterior surfaces of a patient with a suspected spinal injury, the log roll maneuver is employed. This is a coordinated procedure requiring at least three people, designed to turn the patient as a single unit while the leader maintains MILS, to prevent secondary spinal injury. This allows for inspection and palpation of the entire posterior surface (20).
Environment: Actively prevent hypothermia. The act of exposing a patient creates a significant risk of heat loss. This is not a comfort measure; it is a critical resuscitation step. As soon as the patient is exposed, cover them with warm blankets. Use fluid warmers for all intravenous crystalloids and blood products. Utilize active warming devices like forced-air warming blankets. Preventing hypothermia is essential to breaking the Trauma Triad of Death (20).
Adjuncts to the Primary Survey
Adjuncts are diagnostic tools integrated into or performed immediately following the primary survey. They must not delay resuscitation or require moving an unstable patient.
eFAST Scan: The Extended Focused Assessment with Sonography for Trauma is a rapid bedside ultrasound to identify life-threatening bleeding. It specifically looks for free fluid (blood) in the pericardial sac (ruling out tamponade), the hepatorenal space (Morison's pouch), the splenorenal space, and the pelvis. The "extended" views assess for pneumothorax and hemothorax (21).
Portable Chest X-Ray (AP view): A vital adjunct used to evaluate for hemothorax, pneumothorax, and pulmonary contusion, and to confirm the correct placement of an endotracheal tube, central lines, and chest tubes (21).
Portable Pelvis X-Ray (AP view): Obtained in any patient with a high-risk mechanism of injury, physical exam findings suggestive of a fracture, or unexplained shock. It is used to identify pelvic ring fractures, which are often associated with life-threatening retroperitoneal hemorrhage (21).
Monitoring: Continuous ECG, pulse oximetry, and end-tidal CO2 (for intubated patients) are mandatory. A urinary catheter is inserted to monitor urine output, which is a sensitive indicator of end-organ perfusion and the adequacy of resuscitation (goal >0.5mL/kg/hr) (3).
Baseline Bloods: An initial set of blood tests should be drawn, including a Full Blood Count, Coagulation Profile, Urea & Electrolytes, and a Group & Save or Crossmatch. A venous or arterial blood gas with lactate is essential for assessing for shock and acidosis.
When to Escalate
A house officer must recognize the limits of their experience and call for senior help immediately in these situations. Early escalation saves lives.
Call Your Senior (MO/Specialist) if:
The patient has an actual or impending airway compromise (e.g., stridor, gurgling, expanding neck hematoma).
The patient is in shock (tachycardia, hypotension) and is not responding to the first unit of blood products.
A life-threatening thoracic injury (e.g., tension pneumothorax, massive hemothorax) is identified or suspected.
The patient has a GCS of ≤ 8 or develops new focal neurological signs (e.g., a blown pupil, unilateral weakness).
The eFAST scan is positive for significant free fluid in the abdomen or pericardium.
You are considering activating the Massive Transfusion Protocol.
You feel out of your depth at any point. It is always safer to call for help early.
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