NLE Emergency & Critical Care Nursing — Principles of Emergency & Critical Care NursingDetailed Explanation

Triage: Sorting Patients by Acuity

Triage comes from the French word 'trier,' meaning 'to sort.' In emergency nursing, triage is the process of rapidly evaluating multiple patients to determine who needs care most urgently — not who arrived first. The fundamental question triage answers is: 'Who cannot wait?' The triage nurse is usually the first clinical contact in the ED, and her initial assessment determines the entire flow of care. In Philippine hospitals that follow DOH guidelines for hospital emergency services, triage is a required component of ED operation. The classic three-tier system categorizes patients as follows: **Emergent (Priority 1 — Red):** Conditions that pose an immediate threat to life, limb, or vision. These patients are seen AT ONCE with no waiting. Examples include: a patient in cardiac arrest, a patient with severe respiratory distress and SpO2 of 82%, a patient with uncontrolled arterial bleeding, a patient with altered consciousness (GCS < 9), active seizures, signs of acute MI (crushing chest pain, diaphoresis, radiation to the jaw/arm), anaphylaxis with stridor, and major trauma. **Urgent (Priority 2 — Yellow):** Serious conditions that are not immediately life-threatening but require attention within 30 to 60 minutes. Delay risks deterioration. Examples include: moderate abdominal pain, stable closed fracture, high-grade fever (>39.5°C) in an adult, a laceration that needs suturing without arterial bleeding, and a patient with controlled asthma attack. **Non-Urgent (Priority 3 — Green):** Stable conditions that can safely wait. These patients will not deteriorate in the next few hours. Examples include: minor sprains, chronic low back pain, mild upper respiratory tract infection, and minor cuts. **Five-Level Triage (Emergency Severity Index or ESI):** Many advanced EDs use a five-level scale: - Level 1: Immediate/Resuscitation (life-threatening, requires immediate intervention) - Level 2: Emergent (high risk, confused, in severe pain, or in distress) - Level 3: Urgent (stable but needs multiple resources — labs, imaging, IV medications) - Level 4: Less Urgent (needs one resource only) - Level 5: Non-Urgent (no resources needed) **Continuous Re-triage:** Triage is never a one-time event. A patient triaged as urgent can deteriorate to emergent while waiting. The nurse must reassess waiting patients regularly. This is a critical safety responsibility and a common NLE examination theme. **Mass-Casualty / Disaster Triage — START System:** In mass-casualty incidents (MCI) such as typhoon disasters, building collapses, or vehicular accidents involving multiple victims — which are unfortunately common in the Philippines — the triage logic shifts from 'the sickest first' to 'the greatest good for the greatest number.' The START triage system (Simple Triage And Rapid Treatment) uses four color tags: - **Black (Expectant/Deceased):** Not breathing even after the airway is opened. In MCI, this patient is NOT resuscitated (no CPR). This is the OPPOSITE of routine ED care — a critical NLE distinction. - **Red (Immediate):** Salvageable life threat. Breathing >30/min, no radial pulse, or cannot follow commands. - **Yellow (Delayed):** Serious but can wait. Walking, breathing, and has a radial pulse. - **Green (Minor/Walking Wounded):** Minor injuries, ambulatory, and can follow commands. The RPM assessment in START: **R**espiration rate, **P**erfusion (radial pulse), **M**ental status (follows commands).

The Primary Survey: ABCDE Framework

The primary survey is the most critical skill in emergency nursing. It is a rapid, systematic assessment designed to identify and immediately treat life-threatening conditions in a specific sequence. The governing rule is absolute: **you do not move to the next letter until you have addressed the current threat.** If a patient has an obstructed airway, you clear it before assessing breathing. This sequence exists because each problem, if left unaddressed, will kill the patient before the next one even becomes relevant. **A — AIRWAY (with Cervical Spine Protection):** Is the airway open and patent? An obstructed airway kills within minutes. Assessment: - Ask the patient to speak. If they speak clearly → airway is patent. - Listen for abnormal sounds: **Stridor** (high-pitched, inspiratory) = partial upper airway obstruction. **Gurgling** = secretions/blood in the airway. **Snoring** = tongue falling back (common in unconscious patients). - Look inside the mouth for blood, vomitus, foreign bodies, or edema. Interventions: - **Head-tilt/chin-lift:** Standard maneuver for non-trauma patients. - **Jaw-thrust:** Used INSTEAD of head-tilt/chin-lift when cervical spine injury is suspected (trauma patients). This is a critical NLE distinction — the jaw-thrust moves the mandible forward to open the airway WITHOUT extending the neck. - **Suctioning:** Clear secretions, blood, or vomitus. - **Oropharyngeal airway (OPA):** Used in unconscious patients without a gag reflex. - **Nasopharyngeal airway (NPA):** Used in patients with intact gag reflex or clenched jaw. - **Definitive airway:** Endotracheal intubation or surgical airway (cricothyrotomy) for total obstruction or inability to maintain airway. - **C-spine immobilization:** In trauma, always maintain inline cervical stabilization throughout the survey. **B — BREATHING:** Having a patent airway does not guarantee adequate breathing. Breathing assessment: - Look: Chest rise and fall, symmetry, use of accessory muscles, respiratory rate (normal: 12-20/min). - Listen: Breath sounds bilaterally (absent? unequal? wheezing? crackles?). - Feel: Air movement from nose/mouth, crepitus on chest wall. - Monitor: SpO2 (goal: ≥ 95%), respiratory rate. Immediate life-threatening breathing emergencies (the '5 Ts' of tension plus trauma): - **Tension pneumothorax:** Absent breath sounds on one side, tracheal deviation AWAY from the affected side, hypotension, distended neck veins. Treatment: NEEDLE DECOMPRESSION — 2nd intercostal space, midclavicular line. - **Open pneumothorax (sucking chest wound):** Seal with three-sided occlusive dressing. - **Massive hemothorax:** Absent breath sounds + dullness to percussion + hemorrhagic shock. - **Flail chest:** Paradoxical chest wall movement. - **Cardiac tamponade:** Beck's Triad — hypotension, muffled heart sounds, distended neck veins. Interventions: Administer high-flow oxygen (10-15 L/min via non-rebreather mask), assist ventilation with bag-valve-mask (BVM), prepare for intubation and mechanical ventilation if needed. **C — CIRCULATION (with Hemorrhage Control):** Once airway and breathing are secured, assess circulation. Hemorrhage is the most preventable cause of trauma death. Assessment: - Pulse: Rate, rhythm, quality (full/bounding = volume overload; weak/thready = shock). - Blood pressure: Hypotension is a LATE sign of shock in adults — by the time BP drops, the patient has lost ≥ 30% of circulating blood volume. - Skin: Color (pallor, cyanosis), temperature (cool/clammy = poor perfusion), moisture. - Capillary refill time (CRT): Normal < 2 seconds. Prolonged CRT indicates poor peripheral perfusion. Interventions: - **Control external hemorrhage:** Direct pressure is first-line. Tourniquets for extremity hemorrhage when direct pressure fails. - **IV access:** Establish TWO large-bore peripheral IV lines (16 to 18 gauge). Large bore = more rapid fluid administration. In children or when IV access is impossible: intraosseous (IO) access. - **Fluid resuscitation:** Isotonic crystalloids (Plain NSS or Lactated Ringer's) are first-line. Blood products for hemorrhagic shock. - **Recognize shock early:** Tachycardia + tachypnea + restlessness = early shock even with NORMAL blood pressure. Types of shock for NLE context: - **Hypovolemic:** Most common in trauma. Decreased preload, decreased CO, increased SVR. - **Cardiogenic:** Heart failure, MI. Decreased CO, increased SVR, may have elevated CVP/JVD. - **Distributive (Septic, Anaphylactic, Neurogenic):** Vasodilation causing decreased SVR. - **Obstructive (Tension pneumothorax, Cardiac tamponade):** Mechanical obstruction to flow. **D — DISABILITY (Neurologic Status):** A rapid neurologic assessment is performed AFTER airway, breathing, and circulation are addressed. **AVPU Scale (Quick neurologic check):** - **A** — Alert: Patient is awake and oriented. - **V** — Voice: Patient responds to verbal stimuli. - **P** — Pain: Patient responds only to painful stimuli. - **U** — Unresponsive: No response to any stimulus. **Glasgow Coma Scale (GCS):** More detailed. Scores Eye opening (1-4) + Verbal response (1-5) + Motor response (1-6). Maximum = 15 (normal), Minimum = 3 (deepest coma). - GCS ≤ 8 = severe brain injury. Consider definitive airway (endotracheal intubation). - GCS 9-12 = moderate brain injury. - GCS 13-15 = mild brain injury. Critical check in D: **Blood glucose level.** Hypoglycemia (blood glucose < 70 mg/dL) is a RAPIDLY REVERSIBLE cause of altered consciousness. Always check blood glucose in any patient with altered mental status — this is a classic NLE examination point. If hypoglycemic: administer 50% dextrose IV. Also assess: Pupil size and reactivity. - Unilateral fixed dilated pupil = uncal herniation (brain herniation compressing CN III). - Bilateral fixed dilated pupils = severe brain injury or drug effect. - Pinpoint pupils = opioid toxicity or pontine lesion. **E — EXPOSURE AND ENVIRONMENT:** Fully undress the patient to identify ALL injuries — hidden wounds, rashes, bruising patterns, or deformities that may not be visible through clothing. Critical considerations: - Remove all clothing. In trauma, this includes cutting garments off. - Log-roll with spinal precautions to inspect the back. - **Prevent hypothermia immediately after exposure** — hypothermia worsens coagulopathy. Use warm blankets, warm IV fluids, and warm the room temperature. **The Trauma Lethal Triad:** Three conditions that form a deadly cycle in trauma patients: 1. **Hypothermia** (< 35°C) → impairs coagulation enzymes 2. **Acidosis** (low pH) → impairs cardiac contractility and coagulation 3. **Coagulopathy** (inability to clot) → worsens hemorrhage → worsens shock → worsens acidosis and hypothermia Preventing hypothermia during E is a critical nursing intervention to break this lethal cycle.

Secondary Survey and SAMPLE History

The secondary survey begins ONLY after the primary survey is complete and all life-threatening conditions have been addressed or are being actively managed. If at any point during the secondary survey the patient deteriorates, the nurse IMMEDIATELY returns to the primary survey (A) and reassesses from the beginning. The secondary survey is a complete, systematic head-to-toe physical assessment combined with a focused patient history. Its purpose is to find all injuries or conditions that were not identified in the rapid primary survey. **The SAMPLE History Mnemonic:** This structured history takes 2-3 minutes and covers the essential background information: - **S — Signs and Symptoms:** What is the chief complaint? When did it start? What makes it better or worse? Describe the character of pain (use OLDCART: Onset, Location, Duration, Character, Aggravating factors, Relieving factors, associated Timing/symptoms). - **A — Allergies:** Any known allergies to medications, foods, or environmental substances? What type of reaction occurs? - **M — Medications:** Current medications — prescription, over-the-counter, herbal, vitamins. Ask specifically about anticoagulants (warfarin, aspirin, clopidogrel), insulin, beta-blockers, and antihypertensives, as these affect emergency management. - **P — Past Medical/Surgical History:** Previous illnesses, hospitalizations, surgeries, and relevant family history. Diabetes, hypertension, asthma, heart disease, and bleeding disorders are particularly significant. - **L — Last Oral Intake:** When did the patient last eat or drink? This is critical for procedural sedation and anesthesia risk. 'Nothing by mouth for 6 hours before surgery' is a standard guideline. - **E — Events Leading to the Presentation:** What happened immediately before the patient came to the ED? For trauma: mechanism of injury, speed, use of seatbelt, airbag deployment, height of fall. For medical: activities at time of symptom onset, any prodromal symptoms. **Head-to-Toe Assessment in the Secondary Survey:** The nurse systematically examines each body region: - Head and face: Scalp lacerations, skull fractures, facial bone stability, eye injuries, oral cavity. - Neck: Tracheal position, neck vein distension, midline tenderness (C-spine), lacerations. - Chest: Full respiratory assessment, heart sounds, rib tenderness, crepitus. - Abdomen: Inspection, auscultation, palpation for tenderness, rigidity, or guarding. Bruising patterns (Cullen's sign = periumbilical ecchymosis indicates retroperitoneal hemorrhage; Grey Turner's sign = flank ecchymosis). - Pelvis: Stability (press gently on iliac crests — pain indicates pelvic fracture). - Extremities: Neurovascular status (pulse, sensation, movement, capillary refill) distal to any injury. - Neurologic: Complete GCS, cranial nerve exam if indicated, motor and sensory assessment. - Back and perineum: Log-roll to inspect the entire posterior surface. **Pain Assessment:** During the secondary survey, the nurse formally assesses pain using a standardized scale (Numerical Rating Scale 0-10, Wong-Baker FACES scale for pediatric or cognitively impaired patients). Pain management is important, but it is addressed AFTER life-threatening conditions are stabilized. **SBAR for Handover Communication:** After the assessment, critical information must be communicated clearly during handover: - **S — Situation:** What is happening right now? Patient name, age, chief complaint. - **B — Background:** Relevant history, allergies, current medications. - **A — Assessment:** Your clinical interpretation of what is wrong. - **R — Recommendation:** What you need from the receiving clinician or what should happen next.

Critical Care Environment and ICU Nursing

The Intensive Care Unit (ICU) represents the most resource-intensive level of nursing care. It is designed for patients with actual or potential life-threatening conditions requiring continuous monitoring and advanced life support. In the Philippine hospital classification system (DOH Administrative Order), Level 3 hospitals are required to maintain ICU facilities with appropriate nurse-to-patient ratios. **Characteristics of the ICU Environment:** - **Continuous monitoring:** 24/7 cardiac monitoring, continuous pulse oximetry, and frequent vital sign assessment (every 1-4 hours or continuously for unstable patients). - **High nurse-to-patient ratio:** ICU standard is 1:1 to 1:2 (one nurse for every 1-2 patients), compared to general wards (1:6 to 1:10). This reflects the complexity and instability of ICU patients. - **Advanced technology:** Mechanical ventilators, central venous lines, arterial lines, pulmonary artery catheters, renal replacement therapy (hemodialysis/CRRT), vasoactive infusions (dopamine, norepinephrine, dobutamine), and intracranial pressure monitors. - **Multidisciplinary team:** Intensivists (physicians), ICU nurses, respiratory therapists, clinical pharmacists, nutritionists, physiotherapists, and social workers. **Bundle-Based Prevention of ICU Complications:** ICU patients are highly vulnerable to iatrogenic (care-related) complications. Evidence-based bundles — packages of interventions proven to work together — are the standard of care: **Ventilator-Associated Pneumonia (VAP) Prevention Bundle:** - Elevate head of bed (HOB) 30 to 45 degrees (semi-Fowler's position) → reduces aspiration. - Daily sedation interruption (Spontaneous Awakening Trial/SAT) → assess readiness for extubation. - Oral care with chlorhexidine every 2-4 hours → reduces oropharyngeal bacterial load. - Subglottic secretion drainage (specialized ETT). - Daily assessment of readiness to extubate. **Central Line-Associated Bloodstream Infection (CLABSI) Prevention Bundle:** - Maximum sterile barrier precautions during insertion (full gown, sterile gloves, cap, mask, large sterile drape). - Hand hygiene before and after any line manipulation. - Chlorhexidine skin antisepsis at insertion site. - Choose femoral site last (highest infection risk); subclavian preferred for infection risk reduction. - Daily review of line necessity → remove as soon as no longer needed. - Sterile dressing changes (per protocol, usually every 5-7 days for transparent dressings or when soiled). **Venous Thromboembolism (VTE) Prevention:** - Sequential compression devices (SCDs) or compression stockings. - Low-molecular-weight heparin (LMWH) prophylaxis when not contraindicated. - Early mobilization — even passive range-of-motion exercises for unconscious patients. **Pressure Injury Prevention (NPUAP/EPUAP Guidelines):** - Turn and reposition every 2 hours. - Pressure-relieving mattresses. - Moisture management (keep skin dry, especially in incontinent patients). - Nutritional support (adequate protein for tissue repair). **Stress Ulcer Prophylaxis:** - Mechanically ventilated patients and those with coagulopathy are at high risk for stress ulcers. - Proton pump inhibitors (PPIs) such as omeprazole or H2 blockers such as ranitidine are used prophylactically. **Family-Centered Care in the ICU:** The ICU environment is profoundly frightening for families. Nurses serve as the primary bridge between the medical team and the family. Key nursing responsibilities: - Explain the purpose of all equipment and alarms in simple, understandable language. - Facilitate family visits (Philippine cultural context: Filipino families place extremely high value on being present with ill relatives — 'pagmamahal at malasakit'). - Support advance care planning and informed consent for procedures. - Address anticipatory grief and provide emotional support. - Involve the family in basic care activities when appropriate (e.g., mouth care, passive exercises) to maintain their sense of connection and participation.

Hemodynamic Monitoring

Hemodynamic monitoring is the continuous or intermittent measurement of cardiovascular pressures and flows to guide fluid management, vasopressor therapy, and assessment of cardiac function. The key principle is that a blood pressure number alone is insufficient — the nurse must correlate parameters with clinical signs of perfusion. **Mean Arterial Pressure (MAP):** MAP represents the average perfusion pressure driving blood through the tissues during one cardiac cycle. It is the most important single number for assessing organ perfusion. Formula: **MAP = Diastolic BP + (Pulse Pressure ÷ 3)** Or: **MAP = (Systolic BP + 2 × Diastolic BP) ÷ 3** Pulse pressure = Systolic BP - Diastolic BP Example: BP = 120/80 mmHg → Pulse pressure = 40 mmHg → MAP = 80 + (40÷3) = 80 + 13.3 = 93.3 mmHg **Target MAP ≥ 65 mmHg** for adequate organ perfusion (especially kidney, brain, gut). MAP < 65 mmHg = inadequate perfusion → organ ischemia risk. **Arterial Line (Art Line / A-Line):** An arterial catheter is placed in a peripheral artery (radial artery is most common, femoral as alternative) and connected to a pressure transducer and monitor for continuous, beat-to-beat blood pressure monitoring. Advantages: Continuous BP monitoring, easy arterial blood gas (ABG) sampling without repeated arterial punctures. **Critical Nursing Responsibilities for Arterial Lines:** - **Zero the transducer** to atmospheric pressure before initial use and whenever readings appear inaccurate. - **Level the transducer at the phlebostatic axis** — defined as the 4th intercostal space at the midaxillary line. This point corresponds to the level of the right atrium. - Transducer TOO HIGH → falsely LOW blood pressure reading (gravity drains fluid away from the sensor) - Transducer TOO LOW → falsely HIGH blood pressure reading - This is a classic NLE examination question! - Maintain continuous flush system (heparinized or plain saline at 3 mL/hr) to prevent clotting. - Monitor insertion site for signs of hemorrhage (A-lines can bleed significantly if disconnected). - Assess distal circulation regularly: check radial pulse distal to the A-line site (Allen's test before insertion verifies collateral ulnar circulation). - Keep the extremity visible and restrained if needed to prevent accidental dislodgement. **Central Venous Pressure (CVP):** CVP is measured through a central venous catheter (CVC) in the superior vena cava and reflects right atrial filling pressure — an estimate of intravascular volume status and right heart function. **Normal CVP: 2-6 mmHg (or approximately 3-8 cmH2O)** Interpretation: - **Low CVP (< 2 mmHg):** Suggests hypovolemia (e.g., hemorrhage, dehydration, burns). Treat with fluid resuscitation. - **High CVP (> 8 mmHg):** Suggests fluid overload, right heart failure, cardiac tamponade, or tension pneumothorax. Caution with further fluids. - **CVP must be interpreted in context** — a CVP of 4 mmHg in a septic patient in shock who is not responding to fluids is very different from a CVP of 4 mmHg in a stable post-operative patient. **Pulmonary Artery (PA) Catheter (Swan-Ganz Catheter):** The PA catheter is a flow-directed, balloon-tipped catheter advanced through the right heart and into the pulmonary artery. It provides the most comprehensive hemodynamic data, including: - Pulmonary artery pressure (PAP): Normal 15-25/8-15 mmHg - Pulmonary Artery Wedge Pressure (PAWP): Estimates left ventricular end-diastolic pressure (preload). Normal: 8-12 mmHg. High PAWP = left heart failure. - Cardiac Output (CO) and Cardiac Index (CI) - Mixed venous oxygen saturation (SvO2): Indicates oxygen extraction by tissues. **Critical Safety: Never inflate the balloon longer than necessary to obtain the wedge pressure (a few seconds maximum). Prolonged balloon inflation can cause pulmonary artery rupture or pulmonary infarction.** **Correlating Numbers with Clinical Signs of Perfusion:** Numbers are meaningless without clinical correlation. The nurse must assess: - **Urine output:** ≥ 0.5 mL/kg/hour indicates adequate renal perfusion. Less than this = oliguria = poor perfusion. - **Skin:** Warm, pink, dry skin = good perfusion. Cool, pale, mottled, clammy skin = poor perfusion. - **Mentation:** Alert and oriented = adequate cerebral perfusion. Confusion, agitation, or decreased LOC = cerebral hypoperfusion. - **Capillary refill time (CRT):** < 2 seconds = normal. > 2 seconds = poor peripheral perfusion. The combination of MAP ≥ 65 + urine output ≥ 0.5 mL/kg/hr + warm skin + clear mentation = adequate tissue perfusion.

This scenario tests integrated ABCDE application. The gurgling airway is addressed first (A). However, the nurse must quickly identify that the 'C' problem (hypotension) is actually being CAUSED by a 'B' problem (tension pneumothorax compressing the mediastinum and impeding venous return to the heart). The classic triad: tracheal deviation away from the affected side + absent breath sounds + hemodynamic instability. GCS 6 (≤8) also indicates the need for definitive airway. This scenario reflects the importance of treating both A and B before C, as the C problem will not resolve until the tension pneumothorax is decompressed.

This problem reinforces two critical principles: (1) Trends matter more than single values — a MAP of 65 mmHg that was 93 mmHg 8 hours ago is very different from a stable MAP of 65 mmHg; (2) Numbers must be correlated with clinical signs. The combination of borderline MAP + clinical deterioration (restlessness, cool mottled skin, oliguria) demands action. The nurse uses all available data to form a clinical picture, consistent with the nursing process assessment phase under RA 9173.

START triage follows a strict decision tree: (1) Can they walk? → Green. (2) Are they breathing? → If no, open airway; still not breathing → Black. (3) RR > 30 OR no radial pulse OR cannot follow simple commands → Red. (4) Everything else (breathing normally, has pulse, follows commands) → Yellow. The critical distinction from routine care is Victim 1 — no resuscitation attempts in mass-casualty settings when resources are limited.

A rising CVP during aggressive fluid resuscitation signals that the heart's ability to accommodate preload is being exceeded. In patients with underlying cardiac or renal dysfunction, even volumes of fluid that appear routine can cause rapid fluid overload. The nurse's role includes both identifying this deterioration early (assessment) and taking appropriate delegated and independent nursing actions.