NLE Emergency & Critical Care Nursing — Principles of Emergency & Critical Care NursingSummary

Triage answers a single clinical question: who cannot wait? The three-tier system categorizes patients as emergent (Priority 1—immediate life/limb threat requiring care within minutes), urgent (Priority 2—serious but stable, treatable within 30–60 minutes), or non-urgent (Priority 3—minor conditions that can wait hours). Examples of emergent conditions include airway obstruction, respiratory distress, cardiac arrest, active severe hemorrhage, acute chest pain suspicious for myocardial infarction, altered consciousness, and seizures. Urgent presentations include moderate abdominal pain, closed fractures with intact distal circulation, high fever, and lacerations needing sutures. Non-urgent include minor sprains, chronic complaints, and mild upper respiratory infections. Many hospitals adopt the five-level Emergency Severity Index (ESI), which further divides the highest-acuity patients into those needing immediate resuscitation versus those who are high-risk but currently stable. Continuous re-triage is essential because patient status can deteriorate while waiting; reassessment is a safety mechanism, not a formality. In mass-casualty or disaster scenarios, the logic inverts toward utilitarian allocation—the greatest good for the greatest number. START triage (Simple Triage And Rapid Treatment) uses color coding: red (immediate, salvageable), yellow (delayed, serious), green (minor/walking wounded), and black (expectant or deceased). Critically, a non-breathing patient who does not open the airway after manual opening is tagged black in disaster triage—a stark ethical contrast to routine ED care where that same patient receives full resuscitation.

The primary survey is the rapid, systematic assessment used to detect and treat immediately life-threatening conditions. It follows an absolute sequence: ABCDE. Do not proceed to the next letter until the current threat is managed. A—Airway (with cervical spine protection): Is the airway patent? Assess ability to speak, listen for stridor or gurgling, inspect for obstruction (tongue, secretions, blood, foreign body, edema). Open the airway with head-tilt/chin-lift or jaw-thrust (use jaw-thrust when cervical spine injury is suspected). Suction secretions, insert an oropharyngeal or nasopharyngeal airway if needed, prepare for definitive airway management. Cervical spine must be immobilized throughout in trauma. B—Breathing: Is the patient ventilating and oxygenating adequately? Assess respiratory rate, depth, symmetry, chest-wall movement, bilateral breath sounds, and oxygen saturation. Administer oxygen immediately. Support ventilation with a bag-valve-mask if rate or depth is inadequate. Treat immediate breathing threats: tension pneumothorax (needle decompression at the 2nd intercostal space, midclavicular line), open pneumothorax (occlusive dressing on three sides), and flail chest (analgesia, splinting, aggressive pulmonary hygiene). C—Circulation (with hemorrhage control): Assess pulse rate, quality, blood pressure, skin color, temperature, and capillary refill (normal <2 seconds; delayed refill indicates shock). Control external bleeding with direct pressure; apply a tourniquet proximal to the bleeding site if direct pressure fails. Establish two large-bore peripheral IVs (16–18 gauge) and initiate fluid resuscitation per protocol. Recognize signs of shock: tachycardia, hypotension, cool clammy skin, delayed capillary refill, altered mental status. D—Disability (neurologic status): Perform rapid neurologic assessment using Glasgow Coma Scale (GCS) or AVPU (Alert, responds to Voice, responds to Pain, Unresponsive). Check pupil size and reactivity (note anisocoria or fixed dilated pupils). Check blood glucose immediately (hypoglycemia is a reversible cause of altered consciousness). E—Exposure/Environment: Fully expose the patient by removing clothing to identify hidden injuries (log-roll carefully if spine injury suspected). Prevent hypothermia by applying warm blankets and administering warmed IV fluids. Maintaining core temperature is a critical nursing responsibility because the lethal triad of hypothermia, acidosis, and coagulopathy worsens outcomes in trauma.

Once the primary survey is complete and life-threatening problems are controlled, the secondary survey is a detailed head-to-toe examination combined with a focused history. The patient is re-exposed fully under warm conditions, and every body region is inspected and palpated systematically: head and face (lacerations, skull crepitus, facial fractures), neck (lacerations, tracheal deviation, jugular venous distension), chest (breath sounds bilaterally, rib fractures, flail segments), abdomen (tenderness, rebound, rigidity, distension), pelvis (fracture, instability), extremities (deformity, swelling, distal pulses and sensation), and posterior surfaces (log-roll to inspect back and buttocks). Obtain a full set of vital signs and order indicated diagnostic testing (blood work, imaging, ECG). The mnemonic SAMPLE structures the focused history: S—Signs and symptoms (chief complaint, progression); A—Allergies (especially to medications and latex); M—Medications (current prescriptions, supplements); P—Past medical history (chronic conditions, previous surgeries, psychiatric history); L—Last oral intake (time and content; important before anesthesia); E—Events leading to presentation (mechanism of injury, time of onset, witnessed vs. unwitnessed). Pain is assessed during the secondary survey but never takes precedence over an unaddressed airway, breathing, or circulation problem. Continual reassessment is routine; any deterioration prompts immediate return to the primary survey.

Hemodynamic monitoring measures pressures and flows within the cardiovascular system to guide fluid and drug therapy in critical illness. Understanding these parameters allows recognition of deterioration before blood pressure collapses. Arterial line provides continuous, beat-to-beat blood pressure measurement and easy access for arterial blood sampling. The transducer must be leveled at the phlebostatic axis (4th intercostal space at the midaxillary line) to ensure accuracy. The transducer must also be zeroed to atmospheric pressure at the start of monitoring. A transducer positioned too high (above the phlebostatic axis) reads falsely low; positioned too low reads falsely high. The insertion site requires vigilant assessment for bleeding, and the distal limb must be monitored for signs of impaired perfusion (coolness, color change, pain, pulse loss). Central venous pressure (CVP) reflects right-heart filling and intravascular volume status. Normal CVP is approximately 2–6 mmHg (or 3–8 cmH₂O when measured in centimeters). Low CVP (<2 mmHg) suggests hypovolemia and indicates need for fluid administration. High CVP (>8 mmHg) suggests fluid overload, right heart failure, or increased intrathoracic pressure (as from tension pneumothorax or positive-pressure ventilation). A pulmonary artery (Swan-Ganz) catheter measures pulmonary artery pressures, cardiac output, and pulmonary artery wedge pressure (PAWP), which estimates left-heart filling pressure. Its clinical use has declined but it remains an examinable concept. Critical rule: never inflate the balloon longer than needed to obtain a wedge reading; prolonged inflation risks pulmonary artery rupture or distal infarction. Mean arterial pressure (MAP) is the single most important perfusion parameter. MAP is estimated as diastolic pressure plus one-third of the pulse pressure, or roughly (systolic + 2 × diastolic) ÷ 3. A MAP of at least 65 mmHg is generally required to perfuse vital organs. Trends matter more than isolated numbers. The nurse correlates hemodynamic values with clinical assessment: warm extremities, good capillary refill, clear mental status, and adequate urine output (≥0.5 mL/kg/hr) confirm that pressures translate into actual tissue perfusion. Shock is present when tissue perfusion is inadequate despite seemingly normal pressures; in this case, lactate levels and base deficit become critical surrogates for tissue oxygenation.

The ICU concentrates the sickest patients and the technology needed to support failing organ systems. Its defining features are continuous cardiac and oxygen-saturation monitoring, a high nurse-to-patient ratio (often 1:1 or 1:2), and capacity for advanced life support: mechanical ventilation, vasoactive infusions, renal replacement therapy, invasive hemodynamic monitoring, and other organ-support therapies. Nursing priorities in this environment extend far beyond the immediate crisis; prevention of iatrogenic (provider-caused) harm is central to critical-care nursing. Evidence-based protocols to prevent common complications include: (1) Ventilator-associated pneumonia (VAP) prevention—elevate the head of the bed 30–45 degrees, interrupt sedation daily (spontaneous awakening trials) to assess readiness for weaning, maintain oral hygiene, and use subglottic secretion drainage if available. (2) Central-line bloodstream infection (CLBSI) prevention—use strict aseptic technique during insertion, maintain aseptic dressing changes, daily assessment of line necessity, and prompt removal when no longer indicated. (3) Pressure injury prevention—frequent position changes every 2 hours, skin assessment at every turn, use of pressure-relief devices, and nutritional support. (4) Venous thromboembolism (VTE) prevention—early mobilization when possible, mechanical prophylaxis (sequential compression devices), pharmacologic prophylaxis per protocol, and assessment for contraindications. (5) Stress-ulcer prophylaxis—histamine-2 receptor blockers or proton-pump inhibitors for high-risk patients (coagulopathy, mechanical ventilation >48 hours, Glasgow Coma Scale ≤8). The nurse is also the family's anchor in a frightening, alarm-filled environment; translating equipment function and alarms into understandable information, supporting realistic expectations, and involving family in decisions consistent with the patient's advance directives and wishes.

Structured communication during handovers and clinical escalation ensures that critical information is not lost in transitions of care. SBAR is the standard framework: S—Situation (the patient's current status and chief problem in one or two sentences; e.g., 'Mr. Santos is a 68-year-old admitted with acute MI, now complaining of increased chest pain'); B—Background (relevant history, past medical conditions, current medications, and context; e.g., 'He has hypertension and diabetes, arrived 6 hours ago with ST elevation in the anterior wall'); A—Assessment (the nurse's interpretation of the situation and current clinical concern; e.g., 'I'm concerned he may be developing cardiogenic shock—his blood pressure has dropped to 90/55, heart rate is 110, and skin is cool'); R—Recommendation (specific action or clarification requested; e.g., 'I recommend checking a lactate level and considering vasopressor support'). SBAR transforms vague, emotional, or scattered reporting into clear, actionable information that the receiving clinician can immediately understand and act upon. This is especially critical in the chaotic ED and ICU where information overload and interruptions are constant threats to safety.

Opening the airway is always the first priority in emergency care. Two techniques are taught: head-tilt/chin-lift and jaw-thrust. Head-tilt/chin-lift is the standard method: place one hand on the patient's forehead and gently tilt the head backward while lifting the chin upward with fingers placed under the bony part of the mandible. This moves the tongue away from the posterior pharynx and opens the airway. Jaw-thrust is used when cervical spine injury is suspected (trauma, mechanism suggesting neck injury, or any unstable patient). Place your fingers behind the angle of the mandible on both sides and thrust the jaw forward without tilting the head. This opens the airway while keeping the cervical spine in a neutral position. The distinction is critical: head-tilt/chin-lift can cause further damage if the cervical spine is injured; jaw-thrust minimizes spine movement. Once the airway is opened, assess patency: Can the patient speak? Are there audible airway sounds (stridor, gurgling)? Is there visible obstruction (tongue, blood, vomitus, foreign body)? If patent and the patient is breathing adequately, position them on their side (recovery position) if unconscious, to prevent aspiration. If not patent or if respiratory effort is inadequate, suction secretions, insert an oral airway (oropharyngeal airway) or nasal airway (nasopharyngeal airway), and prepare for definitive airway management (intubation, surgical airway). In the Philippines, where many hospitals have limited ICU beds, the emergency nurse must be skilled at manual airway opening and bag-valve-mask ventilation, as intubation capability may not be immediately available.

Rapid neurologic assessment in the primary survey uses either the Glasgow Coma Scale (GCS) or the simpler AVPU mnemonic. AVPU is a four-point scale used in the primary survey because it is rapid: A—Alert (patient is awake and oriented or at least awake); V—responds to Voice (patient does not spontaneously speak but does respond when spoken to); P—responds to Pain (patient does not respond to voice but does respond to a painful stimulus such as pinching the trapezius or nail-bed pressure); U—Unresponsive (patient makes no response to voice or pain). Any patient who is not Alert warrants immediate investigation: hypoxia, hypercapnia, hypoglycemia, intracranial hemorrhage, sepsis, or drug intoxication can all present as altered consciousness. Always check blood glucose in any patient with altered mental status because hypoglycemia is rapidly reversible if recognized and treated. The Glasgow Coma Scale is more detailed, assigning points in three categories—eye opening (E), verbal response (V), and motor response (M)—for a maximum of 15 and minimum of 3. GCS ≤8 indicates severe brain injury and is an indication for intubation to protect the airway. GCS 9–12 is moderate injury; GCS 13–15 is mild. The GCS is used in the secondary survey and continuously in critical care. Always document the specific score (e.g., GCS 11: E3V4M4) because trends in GCS are more important than the absolute number. Pupil size and reactivity are also assessed: equal and reactive pupils suggest normal intracranial pressure; dilated or fixed pupils may indicate intracranial hemorrhage, cerebral herniation, or brainstem injury.

Uncontrolled hemorrhage is a leading cause of preventable death in trauma. External bleeding is controlled with direct pressure—apply a clean cloth and apply firm, continuous pressure to the bleeding site. Do not remove the cloth to check if bleeding has stopped; instead, add additional layers on top if needed. Elevation of the affected limb (if no fracture is suspected) can aid in bleeding control. If direct pressure fails, a tourniquet is applied proximal (above) the bleeding site. In the Philippine context, where pre-hospital care is often limited, the ED nurse must be prepared to apply or teach tourniquet application. Once bleeding is controlled, IV access is established (two large-bore IVs, 16–18 gauge) and fluid resuscitation begins per protocol. The goal is to restore tissue perfusion without causing excessive fluid overload. Signs of shock—inadequate tissue perfusion—include tachycardia, hypotension, cool clammy skin, delayed capillary refill, altered mental status, and low urine output. Initial fluid resuscitation typically uses isotonic crystalloids (normal saline or Lactated Ringer's). Massive transfusion protocols exist for patients with severe hemorrhage, using a balanced ratio of packed red blood cells, fresh frozen plasma, and platelets. The nurse must recognize shock early and escalate care immediately because shock, once established, is difficult to reverse and leads to organ failure and death.

In mass-casualty situations (MVAs with multiple injuries, natural disasters, terrorist incidents) or when resources are severely limited, the ethical principle of triage shifts from individual beneficence (doing the most good for each patient) to utilitarian allocation (the greatest good for the greatest number). The START (Simple Triage And Rapid Treatment) protocol uses color tags and rapid assessment to sort patients: RED (immediate, salvageable)—patient has a life-threatening condition but is salvageable with immediate care; examples are airway obstruction, respiratory distress, uncontrolled hemorrhage, or altered consciousness. YELLOW (delayed)—patient is seriously injured but can wait; examples are fractures, moderate bleeding controlled by pressure, or head injury with normal consciousness. GREEN (minor, walking wounded)—patient has minor injuries and can walk and help themselves; examples are sprains, lacerations, or minor soft-tissue injuries. BLACK (expectant or deceased)—patient is deceased or has injuries incompatible with survival given available resources; this includes patients with no respirations after airway opening, severe head/thoracic trauma, or massive burns covering >90% of the body. A critical distinction from routine ED care: in disaster triage, a non-breathing patient who does not begin spontaneous respirations after airway opening is tagged BLACK. In routine ED care, that same patient would receive full resuscitation including intubation and advanced cardiac life support. This ethical shift reflects resource scarcity and the principle that some patients' outcomes cannot be changed with available resources, so those resources must be directed toward salvageable patients. Understanding this distinction is crucial for the Filipino nurse, particularly in underserved regions where mass-casualty events (typhoons, floods, earthquakes) are periodic realities.