NLE Emergency & Critical Care Nursing — Trauma, Poisoning & Environmental EmergenciesStudy Notes

Multiple (polytrauma) refers to injury affecting two or more body systems or regions. The critical nursing challenge is that one dramatic but survivable injury—such as a visible leg fracture or facial trauma—can distract the entire team from a silent, life-threatening injury such as a tension pneumothorax, massive intra-abdominal hemorrhage, or spinal cord injury. This is why the structured ABCDE primary survey exists: to find and treat immediately lethal problems before proceeding to definitive care. **A—Airway with Cervical Spine Control:** Assume any significant blunt trauma victim has a cervical spine injury until proven otherwise. Open the airway using a jaw-thrust maneuver (not a head-tilt chin-lift, which flexes the neck). Maintain cervical spine immobilization with a collar and backboard until imaging clears the spine. A patent airway is useless if the patient aspirates, so suction gently, position the patient supine, and have suction equipment immediately available. If the patient has stridor, hoarseness, or difficulty swallowing after facial trauma, suspect laryngeal injury; plan for early intubation. **B—Breathing:** Assess bilateral air entry by auscultating the lung bases (where breath sounds are quietest and most likely to reveal asymmetry). Three immediately life-threatening conditions demand immediate treatment before secondary survey: - **Tension pneumothorax:** The collapsed lung compresses the heart and great vessels, causing hypotension and cardiovascular collapse. Signs are severe dyspnea, hypotension, distended neck veins, tracheal deviation, and unilateral absent breath sounds. Treat immediately with a needle (14-gauge) in the 2nd intercostal space, midclavicular line to release the pressure; follow with chest tube insertion. - **Open pneumothorax ("sucking chest wound"):** A penetrating chest wound allows air to enter the pleural space with each breath, impairing ventilation. Seal it with an occlusive dressing taped on three sides (the fourth side acts as a flutter valve allowing air to escape during exhalation but preventing re-entry with inhalation). Follow with chest tube placement. - **Massive hemothorax:** A large volume of blood in the pleural space (more than 1,500 mL) compresses the lung and causes hypovolemic shock. Suspect it with dullness to percussion, absent breath sounds, and hypotension. Insert a large-bore chest tube (32–40 Fr) and prepare for fluid resuscitation and likely operative intervention. **C—Circulation and Hemorrhage Control:** Hemorrhage is the leading preventable cause of trauma death. The nurse must act decisively. For external bleeding: - Apply direct pressure with a cloth; maintain it for several minutes before checking. - If bleeding does not stop, apply a **tourniquet above the level of bleeding** (higher pressure is needed to compress the artery; a tourniquet below the wound is ineffective). Use a commercial tourniquet (CAT, SOF-T) if available; document the time applied. - Obtain **two large-bore IVs (16-18 gauge minimum)**, preferably in the antecubital fossae. - For major hemorrhage (Class III–IV), begin **balanced resuscitation with blood products:** in trauma centers with massive transfusion protocols, the typical ratio is 1 unit fresh frozen plasma : 1 unit packed RBCs : 1 unit platelets, or a similar 1:1:1 approach. This is far superior to crystalloid alone, which can dilute clotting factors and worsen coagulopathy. - Watch for the **trauma lethal triad:** hypothermia + metabolic acidosis + coagulopathy. These three interact catastrophically: cold reduces enzyme function and platelet effectiveness, acidosis worsens coagulopathy, and coagulopathy leads to ongoing blood loss and shock, which further cools the patient. Preventing hypothermia is therefore a genuine resuscitation priority—remove wet clothing, apply warm blankets, infuse warmed fluids. - Assess for occult (hidden) bleeding in the chest (tension/massive hemothorax, cardiac tamponade), abdomen (splash on lap in blunt trauma = intra-abdominal bleeding), pelvis (pelvic fracture = massive retroperitoneal bleed), and thighs (femur fracture can lose 1.5–2 L of blood into the thigh). **D—Disability:** Assess neurological status using the **Glasgow Coma Scale (GCS)** and pupil reactivity. A falling GCS suggests rising intracranial pressure, evolving shock, or ongoing intoxication. Serial GCS scores are more informative than a single number; a drop of 2 or more points is significant. Dilated, fixed pupils suggest brainstem herniation and are a grave sign. **E—Exposure and Environment:** Undress the patient completely to find hidden wounds (abrasions, penetrating injuries, burns). However, hypothermia is a major killer in trauma, so aggressively prevent heat loss: apply blankets, use warm fluids, keep the environment warm, and monitor core temperature. In multiply injured patients in shock, hypothermia worsens survival. After the primary survey, perform a **secondary survey** (a systematic head-to-toe examination), obtain relevant imaging and labs (e.g., trauma panel, type and crossmatch, coagulation studies), and transfer the patient to definitive care. **Continuous reassessment is essential:** a stable trauma patient can deteriorate suddenly from occult bleeding, so repeat the ABCDE and watch vital signs and urine output closely.

Burns are among the most severe injuries because they threaten life through three mechanisms: (1) airway compromise and inhalation injury, (2) massive fluid loss leading to hypovolemic shock, and (3) infection. Nurses must rapidly assess burn depth and extent, secure the airway early, and initiate aggressive fluid resuscitation. **Burn Depth Classification:** - **Superficial (1st degree):** Epidermis only; erythema, no blistering, painful. Example: sunburn. Heals without scarring in 3–5 days. - **Partial-thickness (2nd degree):** Involves epidermis and part of dermis. Red, blistered, very painful (nerves intact). Capillary refill is present. Heals in 2–4 weeks, with potential for scarring. - **Full-thickness (3rd degree):** Destroys epidermis and entire dermis; may extend to subcutaneous tissue. Appears waxy, charred, leathery, painless (nerves destroyed). Will require skin grafting; deep wound contracture and scarring are inevitable. For estimating total body surface area (TBSA) burned, use the **Rule of Nines in adults:** - Head (entire): 9% - Each arm (entire): 9% each - Each leg (entire): 18% each - Anterior trunk: 18% - Posterior trunk: 18% - Perineum: 1% Total: 100% For pediatric patients, the head comprises a larger percentage (roughly 18%) because children have proportionally larger heads; adjust the rule accordingly. **Airway and Inhalation Injury:** This is the **first priority in burn management.** Inhalation injury dramatically worsens prognosis. Suspect it if: - Face, nose, mouth, or singed nasal hair are present (indicates heat exposure). - Soot or carbonaceous material is visible in the mouth or in sputum. - The patient is hoarse or has stridor (laryngeal edema). - The burn occurred in an enclosed space (house fire, vehicle). - Carbonmonoxide poisoning is suspected (enclosed space fire). Airway edema can develop rapidly (over minutes to hours). **Do not wait for complete airway obstruction; intubate early if any signs of inhalation injury are present.** Once the airway is swollen shut, emergency cricothyrotomy or tracheostomy may be the only option. A patient who can speak clearly now may be unable to be intubated in an hour. **Fluid Resuscitation—The Parkland Formula:** Large-area burns cause catastrophic fluid loss into the burn wound and surrounding tissues (third-spacing). Without aggressive IV fluid replacement, the patient will develop hypovolemic shock within hours. The **Parkland formula** is a widely used guide: **Total fluid over 24 hours = 4 mL × body weight (kg) × %TBSA burned, using lactated Ringer's solution (not normal saline, which causes hyperchloremic acidosis).** **Key points:** - **Give half of the total volume in the first 8 hours** (timed from the moment of injury, not from arrival at hospital). - Give the remaining half over the next 16 hours. - **Titrate to urine output:** adults should produce 0.5 mL/kg/hr of urine; children and patients with electrical burns should produce 1.0 mL/kg/hr. If urine output is below target, increase the infusion rate; if above target, decrease it. - Insert a Foley catheter to monitor urine output accurately. - Monitor serum electrolytes (hypernatremia is common in large burns), acid-base status, and creatinine. **Example:** A 70-kg adult with a 30% TBSA burn arrives 1 hour after injury. Total 24-hour fluid = 4 × 70 × 30 = 8,400 mL of lactated Ringer's. In the first 8 hours: 8,400 ÷ 2 = 4,200 mL, or about 525 mL/hr. Target urine output: 0.5 × 70 = 35 mL/hr. Monitor urine output and adjust the infusion rate to hit the target. **Wound Care:** Remove all clothing and jewelry (jewelry can constrict as edema develops). Do not peel away tissue that is adherent to the burn; doing so increases infection risk and causes pain. Cover the burn with a clean dry dressing or sterile plastic sheeting temporarily to prevent heat loss and reduce infection risk. Provide analgesia (opioids are required for severe burns; give them IV because poor perfusion impairs absorption). Update tetanus prophylaxis. **Carbon Monoxide Poisoning:** Fires in enclosed spaces produce carbon monoxide (CO), which binds hemoglobin with an affinity 200 times that of oxygen, creating carboxyhemoglobin (COHb). **Pulse oximetry will read normal or near-normal because it cannot distinguish COHb from oxyhemoglobin.** Symptoms of CO poisoning include headache, confusion, loss of consciousness, and cardiac dysrhythmias. **Treat with 100% oxygen via non-rebreather mask or mechanical ventilation.** Check arterial blood gas and carboxyhemoglobin level if available. Hyperbaric oxygen may be considered for severe CO poisoning (COHb > 25%, loss of consciousness, cardiac involvement) but should not delay initial high-flow oxygen. **Special Considerations:** - **Electrical burns** may cause deep muscle necrosis (rhabdomyolysis) and myoglobinuria, so target urine output is higher (1.0 mL/kg/hr) and urinalysis should be monitored for myoglobin. - **Chemical burns:** Remove contaminated clothing; irrigate with copious water (not neutralizing agents); cover with clean dressing; transport for specialist evaluation. - **Transfer to a burn center** is indicated for TBSA > 10% in adults (or > 5% in very young or elderly), full-thickness burns, inhalation injury, electrical burns, circumferential burns, or burns in high-risk patients.

Acute poisoning (drug overdose or toxin ingestion) is managed using a three-stage approach: (1) support the ABCs (the vast majority of poisoned patients survive with supportive care alone), (2) identify the toxin and decontaminate if appropriate, and (3) administer a specific antidote if one exists and enhance elimination if possible. **It is crucial to understand that most poisonings are managed with supportive care; antidotes are the exception, not the rule.** **Approach to the Poisoned Patient:** 1. Secure the airway and provide oxygen; monitor cardiac rhythm and vital signs continuously. 2. Obtain a history: what was ingested, when, how much, and whether there is concurrent use of other substances. 3. Perform a physical examination looking for toxidromes (clusters of signs/symptoms that suggest a class of poison). 4. Obtain relevant labs: blood glucose, electrolytes, renal and liver function, blood gas, toxicology screen (urine and/or serum). 5. Decontaminate if appropriate (activated charcoal, gastric lavage in selected cases). 6. Give a specific antidote if one exists. 7. Enhance elimination (dialysis, urinary alkalinization) if indicated. **Decontamination Methods:** **Activated Charcoal:** Activated charcoal adsorbs many ingested toxins to its surface, preventing GI absorption. It is most effective **within 1 hour of ingestion** but can be given up to several hours later for some toxins. Typical dose: 50–100 g (adult). **Contraindications:** - Unprotected airway (decreased consciousness without intubation): charcoal aspiration into the lungs causes fatal pneumonitis. - Ingestion of corrosives or hydrocarbons (inducing vomiting or charcoal can cause re-exposure and aspiration injury). - Ingestion of substances not absorbed by charcoal (alcohols, iron, lithium, corrosives). **Gastric Lavage:** Gastric lavage (stomach pumping) was historically used but is **no longer routinely recommended** because it is often ineffective, carries aspiration risk, and can delay more effective interventions. It may be considered in rare cases of massive recent ingestion in a patient with a protected airway, but activated charcoal is preferred. **Induced Emesis (Ipecac):** **Never used anymore.** It is ineffective, dangerous, and has been withdrawn from most markets. **Critical Rule:** **Never induce vomiting after ingestion of a caustic substance (strong acids or bases) or a hydrocarbon (gasoline, kerosene, paint thinner).** Vomiting re-exposes the esophagus and pharynx to the caustic material and risks aspiration into the lungs, worsening injury dramatically. **Key Antidotes—High-Yield for NLE:** Memoriz these poison-antidote pairings; they appear frequently in exams: **1. Opioids → Naloxone (Narcan)** - Mechanism: Competitive opioid-receptor antagonist. - Use: Reverses opioid-induced respiratory depression, sedation, and hypotension. - Dose: 0.4–2 mg IV (adult); may repeat every 2–3 minutes if needed. - **Critical:** Naloxone's duration is shorter than most opioids (30–90 minutes), so the patient may re-sedate; monitor for relapse and repeat doses or use an infusion. - Watch for acute opioid withdrawal (agitation, autonomic hyperactivity) but do not withhold naloxone to avoid withdrawal; respiratory depression kills. **2. Acetaminophen (Paracetamol) → N-Acetylcysteine (NAC)** - Mechanism: NAC replenishes hepatic glutathione, which conjugates acetaminophen's toxic metabolite (NAPQI), preventing hepatic necrosis. - Use: Most effective within 8 hours of ingestion; still beneficial if given up to 24 hours post-ingestion. - Dose: Loading dose 150 mg/kg IV over 1 hour, then second dose 50 mg/kg over 4 hours, then third dose 100 mg/kg over 16 hours (IV protocol) or oral dosing as an alternative. - Check serum acetaminophen level at 4 hours post-ingestion and compare to the nomogram to determine if NAC is needed. **3. Organophosphate and Anticholinesterase Poisoning → Atropine + Pralidoxime** - Mechanism: Organophosphates (insecticides, nerve agents) irreversibly inhibit cholinesterase, causing acetylcholine accumulation. - Toxidrome (muscarinic and nicotinic signs): Salivation, Lacrimation, Urination, Defecation, GI distress, Emesis (the **SLUDGE acronym**). Also bradycardia, bronchospasm, miosis (pinpoint pupils), fasciculations (visible muscle twitching). - **Atropine:** Blocks muscarinic (parasympathetic) effects; dries secretions and reverses bradycardia, bronchospasm, and miosis. Give IV, titrate to clinical effect (dry secretions, normal heart rate). - **Pralidoxime (2-PAM):** Reactivates cholinesterase by removing the phosphate group from the enzyme, but only if given early (within 24–48 hours of exposure). Give after atropine. **4. Digoxin Toxicity → Digoxin-Specific Antibody Fragments (Fab)** - Mechanism: Fab fragments bind digoxin with extremely high affinity, removing it from cardiac tissue and facilitating renal clearance. - Use: For life-threatening dysrhythmias (ventricular tachycardia, high-degree AV block) or hyperkalemia (>5.5 mEq/L) due to digoxin toxicity. - Dose: Based on estimated digoxin body load or serum level; calculated carefully (highly variable dosing). - Effect: Dysrhythmias usually reverse within 30 minutes. **5. Benzodiazepine Poisoning → Flumazenil** - Mechanism: Competitive GABA-receptor antagonist; reverses benzodiazepine sedation. - **Caution:** Use is controversial. **Flumazenil can precipitate seizures in:** * Chronic benzodiazepine users (withdrawal seizures). * Mixed overdoses (especially with tricyclic antidepressants). * Patients with underlying seizure disorder. - **Recommendation:** Use flumazenil rarely and only in specific situations (e.g., isolated benzodiazepine overdose in a non-dependent patient) with seizure precautions. Most poisoned benzodiazepine patients are managed with supportive care and intubation if needed. **Additional High-Yield Antidotes:** - **Beta-blockers → Glucagon:** Bypasses beta-adrenergic receptors, increasing cAMP and improving cardiac contractility and chronotropy. - **Heparin → Protamine sulfate:** Reverses anticoagulation by neutralizing heparin. - **Warfarin → Vitamin K:** Restores synthesis of clotting factors II, VII, IX, X; takes 12–24 hours to work, so fresh frozen plasma is used for acute reversal. - **Iron → Deferoxamine:** Chelates iron and facilitates urinary excretion. - **Methanol and Ethylene Glycol → Fomepizole:** Inhibits alcohol dehydrogenase, preventing metabolism to toxic metabolites (formate from methanol, oxalate from ethylene glycol). - **Cyanide → Hydroxocobalamin:** Binds cyanide, forming cyanocobalamin (vitamin B12), which is excreted in urine. Preferred over the older sodium thiosulfate. **Toxidromes—Recognizing Poison Classes:** When the specific toxin is unknown, recognizing a toxidrome helps narrow the diagnosis: - **Anticholinergic (atropine-like):** Dilated pupils, dry skin, tachycardia, hyperthermia, agitation, urinary retention, decreased GI motility. Toxins: antihistamines, anticholinergics, atropine. Mnemonic: "Hot as a hare, dry as a bone, blind as a bat, red as a beet, mad as a hatter." - **Cholinergic (organophosphate-like):** SLUDGE (salivation, lacrimation, urination, defecation, GI distress, emesis), bradycardia, bronchospasm, miosis, fasciculations. - **Sympathomimetic (stimulant):** Tachycardia, hypertension, hyperthermia, mydriasis (dilated pupils), agitation, tremor, diaphoresis. Toxins: cocaine, amphetamines, pseudoephedrine. - **Opioid:** Miosis (pinpoint pupils), respiratory depression, decreased mental status, bradycardia, hypotension, decreased GI motility. Reversed by naloxone. - **Sedative-hypnotic (depressant):** Decreased mental status, respiratory depression, bradycardia, hypotension, hypothermia. Toxins: benzodiazepines, barbiturates, alcohol. **Supportive Care—The Foundation:** The most critical intervention in most poisonings is **supportive care:** - Secure the airway and intubate if GCS ≤ 8 or if unable to protect the airway. - Provide 100% oxygen and maintain normal ventilation (normal PaCO2). - Establish IV access and correct hypoglycemia (give dextrose if glucose < 60 mg/dL), electrolyte abnormalities, and acid-base disturbances. - Maintain core temperature; prevent hypothermia in sedated patients. - Monitor cardiac rhythm continuously; treat dysrhythmias. - Renal or hepatic dysfunction may prolong drug metabolism; anticipate this and titrate medications accordingly.

Bites and stings are common environmental emergencies in the Philippines, where venomous snakes, scorpions, and spiders are native. Each requires specific management. **Snakebite:** Venomous snakes in the Philippines include the cobra, pit viper (locally called "three-step snake" because victims die in three steps), and krait. Venom causes tissue damage, systemic toxicity, and coagulopathy. **Management principles:** - **Immobilize the limb at or below heart level.** Elevation worsens venom spread; keeping the limb at heart level slows lymphatic drainage and venom absorption. - **Keep the patient calm and still.** Physical activity increases blood flow and accelerates venom absorption; treat anxiety. - **Remove constrictive items** (rings, bracelets) before swelling worsens. - **Mark the advancing edge of swelling with a pen and note the time.** Serial marking shows the rate of venom spread and helps guide antivenom dosing and assess treatment response. - **Transport urgently to a medical facility.** Do not waste time with folk remedies. - **Avoid:** * Ice or cold application (worsens tissue damage from venom-induced coagulopathy). * Cutting and sucking (increases tissue damage, causes excessive bleeding, does not remove significant venom). * Arterial tourniquets (cuts off circulation and causes tissue loss); a loose pressure immobilization bandage (like a sprain wrap) around the entire limb is acceptable if transport is delayed, but even this is controversial and should be removed at hospital. - **Give antivenom** if signs of envenomation are present (swelling, coagulopathy, neurological symptoms). Antivenom is derived from horse serum and carries a risk of serum sickness and anaphylaxis, so it is reserved for confirmed envenomation. Test for hypersensitivity first (intradermal test if available). Most Filipino hospitals stock polyvalent antivenom covering the common local species. - Monitor coagulation parameters and platelet count; severe envenomation causes disseminated intravascular coagulation (DIC). - Tetanus prophylaxis. **Insect Stings (Bee, Wasp, Hornet):** - **Remove the stinger.** A bee-stinger venom sac continues to inject venom for several minutes after detachment; scrape it off with the edge of a card or knife (do not pinch it, which can squeeze more venom). - Local reactions (pain, erythema, swelling at the sting site) are managed with local anesthetics, antihistamines, and topical corticosteroids. - **Systemic (anaphylactic) reactions** are rare but life-threatening: * Symptoms: urticaria, angioedema, bronchospasm, stridor, hypotension, cardiovascular collapse. * Treatment: **Intramuscular epinephrine 0.3–0.5 mg (1:1000 solution) IM immediately** (not IV, which risks cardiac dysrhythmias). Repeat every 5–15 minutes if needed. Follow with IV access, antihistamine (diphenhydramine), corticosteroid (methylprednisolone), and beta-2 agonist inhaler if bronchospasm. Observe for biphasic reaction (anaphylaxis recurring hours later). - Patients with severe reactions should receive an epinephrine auto-injector and instructions for future use. **Animal and Human Bites:** - **Irrigate copiously** with normal saline or tap water; high-pressure irrigation helps remove bacteria and debris. - Explore for **tendon and nerve injury**, especially in hand bites. - Obtain imaging (X-ray) to rule out fracture or embedded teeth. - **Update tetanus prophylaxis** (Td or Tdap). - **Assess rabies risk:** Mammalian bites (dog, cat, bat, raccoon, monkey) carry rabies risk if the animal is not known to be vaccinated or if it is wild. Post-exposure prophylaxis (rabies immunoglobulin + rabies vaccine series) should be given **as soon as possible** (ideally within 24 hours, but up to several weeks post-exposure may be beneficial). - **Antibiotics:** Cat and human bites are at high risk for serious infection; consider **amoxicillin-clavulanate** or a fluoroquinolone + clindamycin. Dog bites are lower risk but still warrant prophylactic antibiotics if high-risk (hand, face, immunocompromised patient, puncture wound). Follow local guidelines. - **Do not suture or close the wound primarily** if it is a high-risk bite (deep, high-velocity injury, time delay > 12 hours); allow it to heal by secondary intention to reduce abscess risk.

Heat-related illness exists on a spectrum: **heat exhaustion** is a state of relative hypovolemia and is recoverable with rest and fluid; **heat stroke** is a life-threatening emergency defined by altered mental status in the setting of elevated core temperature, and it requires aggressive immediate cooling to prevent death and permanent organ damage. **Heat Exhaustion:** - **Definition:** Excessive heat exposure with heavy sweating, resulting in relative hypovolemia and dehydration, **with preserved mental status** (normal or mildly confused, but not severely altered). - **Signs and symptoms:** * Heavy sweating (patient is still sweating, indicating the thermoregulatory system is still working). * Weakness, fatigue, dizziness, headache, nausea. * Core temperature may be normal or only mildly elevated (up to 38–39°C). * Tachycardia, tachypnea, normal or low blood pressure. * Mental status intact (key difference from heat stroke). - **Management:** Rest in a cool environment, remove excess clothing, lie flat with legs elevated, drink cool fluids (if able to tolerate), apply cool water or ice to the skin. This is a self-limited condition; the patient recovers within 30 minutes to 1 hour with these measures. - **Risk factors:** Prolonged exertion in heat, inadequate fluid intake, alcohol use, obesity, poor fitness, medications that impair sweating (anticholinergics). **Heat Stroke:** - **Definition:** Core temperature > 40°C (104°F) with **altered mental status** (confusion, irritability, delirium, seizures, coma). This is a medical emergency. - **Two types:** * **Classic (non-exertional) heat stroke:** Occurs in elderly, chronically ill, or sedentary individuals in a prolonged heat wave. Often with inadequate fluid replacement. * **Exertional heat stroke:** Occurs in young, healthy individuals during intense physical activity (military training, sports, laborers in heat). Can develop rapidly, even with environmental temperatures not extremely high, because metabolic heat production is enormous. - **Signs and symptoms:** * Core temperature > 40°C. * Altered mental status: confusion, delirium, personality change, seizures, loss of consciousness. * **Skin:** Classic heat stroke may have hot, dry skin (sweating has ceased because of thermoregulatory collapse). Exertional heat stroke may have continued sweating, which can be misleading. * Hyperventilation and tachycardia; may have hypotension in advanced cases. * Multi-organ failure develops rapidly: rhabdomyolysis (myoglobinuria), acute kidney injury, hepatic dysfunction, DIC. - **Management—IMMEDIATE AND AGGRESSIVE COOLING IS THE PRIORITY:** * **Do not delay cooling for transport, imaging, or laboratory confirmation.** Every minute at a high core temperature increases mortality and permanent neurological damage. * Remove clothing entirely. * **Evaporative cooling:** Spray the patient with water and direct large fans to promote evaporation. This is effective and recommended. * **Ice or cold-water immersion:** Immerse the patient in ice-water or spray with ice water. This is highly effective for exertional heat stroke, though access may be limited in some settings. Some data suggest immersion cooling is superior to evaporative cooling. * **Cold packs:** Apply ice packs to high-heat-loss areas: groin (femoral vessels), axillae (axillary vessels), neck (carotid arteries). These anatomically target large blood vessels near the surface, maximizing cooling. * **Cold IV fluids:** Infuse normal saline cooled to 4°C. This adds to core cooling but is slow (typically lowers core temperature by only 1–2°C over an hour) and should not be the sole cooling method. * **Cooled humidified oxygen** and cooled gastric or rectal lavage are additional active cooling measures for severe cases. * **Continue cooling until core temperature reaches 38.5°C,** then pause cooling to avoid hypothermia ("afterdrop"). * Monitor core temperature continuously (esophageal probe, urinary catheter temperature, or rectal thermometer; avoid oral because the patient may have seizures or altered mental status). * Treat complications: IV fluids for hypovolemia, dialysis for acute renal failure from rhabdomyolysis, correction of coagulopathy, management of seizures. - **Prognosis:** Mortality is 10–50% in hospitalized heat stroke patients, and survivors often have permanent neurological sequelae (cerebellar dysfunction, cognitive impairment). Recovery depends on the duration of hyperthermia and the speed of cooling. - **Antipyretics do NOT work in heat stroke.** Acetaminophen and NSAIDs are ineffective because the problem is not a raised hypothalamic set point (as in infection) but rather an environmental heat load. External cooling is the only effective approach. **Differentiating Heat Exhaustion from Heat Stroke—Critical for NLE:** | Feature | Heat Exhaustion | Heat Stroke | |---------|-------------------|-------------| | Core temperature | Normal to 38–39°C | > 40°C | | Mental status | **Intact** | **Altered** (confusion, seizures, coma) | | Skin | Sweating, cool or warm | Hot (may be dry or sweating in exertional) | | Severity | Self-limited; recovers with rest/fluids | **Medical emergency** | | Management | Rest, cool place, fluids | **Immediate aggressive cooling** | | Mortality | Near zero | 10–50% | **Key Points for Prevention:** - Ensure adequate hydration during prolonged heat exposure. - Modify activity intensity and duration in hot environments. - Acclimatize gradually to heat over 1–2 weeks. - Monitor high-risk individuals (elderly, obese, chronic disease, medications). - Recognize early signs (weakness, headache) and move to a cool place immediately.

Hypothermia is a core temperature below 35°C (95°F). As the body cools, metabolism slows dramatically, reducing oxygen demand and paradoxically improving survival even after prolonged periods of apparent death. The key nursing principle is "**not dead until warm and dead**"—resuscitation should be prolonged in hypothermia because recovery after hours of circulatory arrest is documented. **Pathophysiology:** - As core temperature drops, shivering ceases (around 30°C), consciousness declines, and eventually cardiac output and respirations become unmeasurable. - At 28°C and below, the heart is irritable and susceptible to **ventricular fibrillation (VF) from rough handling.** This is called the **"immersion syndrome" or "rescue collapse."** A patient who appears dead (no pulse, no respirations) but is severely hypothermic may still be in VF and resuscitatable. - Cold temperatures slow metabolic rate, reducing oxygen demand. A patient can survive 30+ minutes of apnea if hypothermic because oxygen consumption is minimal. - **Peripheral vasoconstriction** shifts blood centrally; the periphery appears cyanotic and feels ice-cold, masking the living status. - As core temperature rises, the heart regains contractility; rewarm slowly to avoid "afterdrop" (paradoxical further temperature drop as cold peripheral blood returns to the core). **Clinical Presentation by Severity:** - **Mild hypothermia (32–35°C):** Alert but may be irritable or confused, shivering present, tachycardia, hypertension, increased respirations. - **Moderate hypothermia (28–32°C):** Altered mental status (apathy, confusion, amnesia), shivering may be present or absent, bradycardia, slow respirations, possible rigidity mimicking rigor mortis. - **Severe hypothermia (< 28°C):** Unresponsive, barely detectable pulse and respirations, bradycardia (HR may be 30 or less), possible VF or asystole, muscles rigid ("wooden" appearance), dilated pupils (may resemble death), core temperature difficult to measure (standard thermometer is not sensitive enough; use low-reading thermometer or esophageal probe). **Management Approach:** **1. Gentle Handling:** - Avoid rough movement; rough handling of a severely hypothermic patient with an irritable heart can trigger VF. - Log-roll the patient onto a stretcher; avoid aggressive CPR compressions if the patient has a barely detectable pulse. - This is NOT an absolute contraindication to CPR (if no pulse is felt for > 60 seconds, begin CPR), but initiation should be deliberate, not traumatic. **2. Rewarming Strategy—Depends on Severity:** **Mild Hypothermia (> 30°C):** - **Passive external rewarming:** Remove wet clothing, provide warm blankets, place in a warm environment (not intense external heat, which causes peripheral vasodilation and afterdrop). - Warm, non-alcoholic beverages by mouth if patient is alert and able to swallow. - No need for intensive rewarming; the patient's own metabolism will generate heat with insulation. **Moderate Hypothermia (28–30°C):** - **Active external rewarming:** Heating pads, warm blankets, warm bathing. - **Active internal rewarming:** Warmed, humidified oxygen; warmed IV fluids (normal saline warmed to 43°C); warm gastric or bladder lavage (less commonly used now). - Goal: Rewarm gradually to avoid afterdrop and cardiac dysrhythmias. **Severe Hypothermia (< 28°C) and Cardiac Arrest:** - **Extracorporeal rewarming (ECMO or cardiopulmonary bypass):** The gold standard for severe hypothermia with cardiac arrest. Rapidly rewarms the core while providing circulatory support, bypassing the failing heart. Available at specialized centers. - If ECMO is not available, use **active external and internal rewarming** (warm blankets, warmed O2, warmed IV fluids, gastric/bladder/pleural lavage). - **Continue CPR and resuscitation throughout rewarming.** Do not pronounce the patient dead while hypothermic until the core temperature has been raised above 35°C. Several cases of full neurological recovery have been documented after > 3 hours of cardiac arrest in hypothermia; one case involved a 7-year-old who was submerged in ice water for 66 minutes, resuscitated with ECMO, and made a full recovery. **3. Specific Considerations:** - **Dysrhythmias:** A characteristic **Osborn wave** (a distinctive deflection on the ECG between the QRS and ST segment) appears with moderate to severe hypothermia. The heart may be in VF but is remarkably resistant to defibrillation while severely cold; typically, defibrillation is deferred until the core temperature exceeds 30°C, unless the patient is already being actively rewarmed. - **Drug administration:** Space medications farther apart (every 10 minutes instead of every 3–5 minutes) during cardiac arrest from hypothermia because cold metabolism is slow. Some protocols defer medications entirely until the core temperature exceeds 30°C. - **Fluid management:** Avoid excessive IV fluids, which cause volume overload during rewarming as peripheral vessels dilate. - **Avoid afterdrop:** Rewarming the core faster than the periphery prevents the return of cold blood to the heart, which paradoxically lowers core temperature further. **4. Complications:** - **Afterdrop:** Continue monitoring core temperature during and after rewarming; continued temperature drop after rewarming begins indicates afterdrop (periphery warming faster than core, causing peripheral vasodilation and return of cold blood to the core). - **Atrial fibrillation:** Common during rewarming and may convert spontaneously as the heart warms; not an absolute indication for intervention. - **Aspiration:** Unconscious hypothermic patients are at risk; intubate if needed. - **Rhabdomyolysis:** Severe shivering in the rewarming phase can cause muscle breakdown; monitor creatine kinase and myoglobin. **5. Prognosis and Prognostication:** - Severe hypothermia carries high mortality (30–50% in cardiac arrest), but full recovery without neurological damage is possible even after prolonged arrest. - Age, core temperature, and duration of arrest are factors, but prognostication is difficult; prolonged resuscitation is justified. - Some institutions use the mnemonic **"HELP" (Heat Escape Lessening Posture)** to describe the position some people assume in cold water (fetal position), which conserves heat—a sign of preserved thermoregulation. **Differential Diagnosis:** - Hypothermia can mimic death (no pulse, no respirations, fixed dilated pupils), so never assume cardiac arrest until rewarming to normothermia. "**Not dead until warm and dead**" is the guideline.

**Near-drowning** (also called submersion injury) is the process of experiencing respiratory impairment from submersion in liquid. The primary pathophysiological problem is **hypoxia**—the inability to extract oxygen from the water. Unlike older teaching that emphasized "fresh-water aspiration vs. salt-water aspiration," modern management recognizes that **hypoxia is the killer in all cases,** and acute management is identical regardless of water type. **Pathophysiology:** - Upon submersion, the victim reflexively holds their breath (dive response). As hypoxia worsens, the victim may struggle and aspirate water, or may experience "dry drowning" (silent aspiration of a small amount of water triggering laryngospasm, preventing water entry into the lungs but also preventing air entry—essentially apnea from reflex laryngospasm). - Loss of consciousness occurs within minutes due to hypoxia; brain death can occur within 4–6 minutes without intervention. - Aspiration of water causes airway obstruction and impairs gas exchange; salt water draws fluid into the lungs (pulmonary edema); fresh water is absorbed across the alveolar-capillary membrane, diluting blood and causing hemolysis (though clinically this is less significant than hypoxia). - **Core temperature drops** if the water is cold; hypothermia offers some neuroprotection (slows metabolism and reduces oxygen demand), but it is not reliable enough to depend on. **Immediate Management at the Scene:** - **Remove the victim from water** immediately; do not attempt rescue breathing in the water (unsafe and ineffective). - Begin **rescue breathing and CPR** as soon as the victim is on dry land. **Oxygenation is the intervention that matters most.** A submersion victim who has not been oxygenated for minutes will require aggressive ventilation. - Do not delay CPR to clear the airway of water; water in the mouth does not prevent successful ventilation, and clearing delays CPR. - Remove wet clothing and prevent hypothermia. - Transport to a medical facility immediately; even an apparently recovered victim may deteriorate hours later from pulmonary edema. **Hospital Management:** - **Airway and ventilation:** Intubate if the patient is unconscious, has a GCS ≤ 8, or shows signs of respiratory distress. Provide 100% oxygen initially. - **Continuous monitoring:** Cardiac dysrhythmias (asystole, bradycardia, VF) are common due to cold water immersion and hypoxia. - **Rewarming:** If cold-water submersion, initiate passive rewarming (remove wet clothing, warm blankets) or active rewarming (warmed IV fluids, warm O2) depending on core temperature. - **Supportive care:** Most submersion victims who are resuscitated require ICU-level observation and support for respiratory failure. - **No routine antibiotics:** Aspiration of contaminated water does not mandate prophylactic antibiotics; treat documented infections if they develop. - **Observation for delayed pulmonary edema:** Even a victim who appears recovered and has normal oxygen saturation on arrival must be observed for **secondary drowning / delayed pulmonary edema,** which can develop hours after submersion. Pulmonary edema causes progressive respiratory distress, hypoxia, and pink frothy sputum; it is due to water damage to the alveolar-capillary membrane and surfactant depletion. **Secondary Drowning / Delayed Pulmonary Edema:** - **Definition:** Progressive pulmonary edema developing hours (typically 1–24 hours) after submersion, even in a victim who initially appeared well. - **Mechanism:** Water damages the alveolar-capillary membrane and depletes surfactant, impairing gas exchange. Fluid accumulates in the alveoli (pulmonary edema). - **Clinical presentation:** Cough, dyspnea, respiratory distress, hypoxia, pink frothy sputum (classic sign), decreased oxygen saturation despite oxygen therapy. - **Management:** Continuous monitoring, supplemental oxygen, possible intubation and mechanical ventilation, diuretics (furosemide), positive end-expiratory pressure (PEEP), and supportive care. - **Prevention:** Observation in the hospital for at least 24 hours even if the patient appears well on arrival; educate families that deterioration can occur at home hours after the incident. **Prognostication:** - Outcome depends on the duration of submersion without oxygenation, water temperature, time to CPR initiation, and underlying health. - Victims who respond to initial CPR and regain consciousness within minutes have a good prognosis for neurological recovery. - Prolonged unconsciousness at arrival (GCS 3–5) carries a poor prognosis, but some recovery has been documented even in victims unconscious for hours if they were cold (neuroprotection from hypothermia). - "**Not dead until warm and dead**"—the maxim from hypothermia applies here too: prolong resuscitation efforts. **Difference Between Fresh and Salt Water—Clinically NOT Significant:** - **Fresh water:** Hypotonic; absorbed across the alveolar membrane, dilutes blood, causes hyponatremia (low sodium) and hemolysis. Clinically, this is less significant than hypoxia. - **Salt water:** Hypertonic; draws fluid into alveoli, causing pulmonary edema. Again, hypoxia is the dominant problem. - **Modern approach:** Acute management is **identical** for fresh and salt water; the focus is airway/ventilation and oxygenation. Electrolyte abnormalities (hyponatremia, hyperkalemia) are managed if they occur but do not drive initial treatment decisions.

Across trauma, burns, poisoning, and environmental emergencies, certain nursing principles are universal and must be practiced consistently to prevent mortality and morbidity. **The Golden Hours and the 'Golden Period':** - **The golden period** for trauma is the first 60 minutes after injury (the "golden hour"), when early resuscitation has the greatest impact on survival. However, some trauma patients require **prehospital interventions (airway management, hemorrhage control, extrication) that may extend this window.** Regardless, rapid transport and early definitive care are paramount. - In poisoning, **time to antidote and decontamination** is critical; activated charcoal is most effective within 1 hour, NAC for acetaminophen is most effective within 8 hours. Do not delay while waiting for confirmatory tests; begin therapy based on clinical suspicion. - In burns, **early intubation** for inhalation injury and fluid resuscitation started **from the time of injury** (not arrival) determine survival. **Continuous Reassessment—The Cornerstone:** - **A trauma or environmental emergency patient is never stable.** Reassess the ABCDE every 5–10 minutes (or whenever a change in clinical status is noted). - **Red flags for deterioration:** * Falling mental status or GCS. * Declining blood pressure or rising heart rate (early shock). * Decreasing urine output (oliguria). * Increasing respiratory rate or work of breathing. * Worsening oxygen saturation despite oxygen therapy. * Development of new murmurs, rashes, or focal neurological findings. - **Act immediately** on any red flag; do not reassess multiple times before intervening. - Example: A trauma patient with an abdominal exam that seems benign on arrival may have ongoing intra-abdominal hemorrhage; if vital signs deteriorate 30 minutes later, **do not repeat the abdominal exam—expedite to the operating room.** **Prevention of Complications Specific to Each Condition:** **Trauma Complications:** - **Missed injuries:** Secondary survey and imaging (chest X-ray, pelvic X-ray, CT) identify injuries missed in the primary survey. Reassess frequently. - **Ongoing hemorrhage:** Monitor urine output, vital signs, and hemoglobin serially; anticipate need for return to OR if hemodynamically unstable. - **Aspiration:** Unconscious patients need airway protection (intubation). - **Hypothermia / lethal triad:** Aggressively prevent heat loss; use warmed IV fluids, warm blankets, avoid cold operating room. - **Infection:** Clean contaminated wounds; give tetanus and antibiotics as appropriate; monitor for signs of infection (fever, elevated WBC). **Burn Complications:** - **Airway loss from edema:** Intubate early; do not wait for complete obstruction. The patient who sounds normal now may not be intubatable in an hour. - **Fluid overload / pulmonary edema:** Titrate fluids carefully to urine output; over-resuscitation causes compartment syndrome and pulmonary edema as much as under-resuscitation causes shock. - **Infection:** Burned tissue is a dead zone for antibiotics; surgical debridement and grafting are necessary. Prophylactic antibiotics are controversial; typically not given, but infection is the leading cause of death in burn patients. - **Contracture and scarring:** Encourage early mobilization and physical therapy; refer to a burn center for specialist wound care. **Poisoning Complications:** - **Aspiration:** Activated charcoal increases aspiration risk; use only with protected airway. Gastric lavage also carries aspiration risk. - **Seizures:** Certain toxins (isoniazid, theophylline, stimulants, antidepressants) cause seizures; have benzodiazepines at the bedside. - **Dysrhythmias:** Tricyclic antidepressants, digitalis, stimulants cause cardiac dysrhythmias; continuous cardiac monitoring is essential. - **Organ failure:** Acetaminophen causes hepatic failure; evaluate PT, INR, bilirubin, and mental status for encephalopathy. Some toxins cause acute kidney injury, requiring dialysis. **Heat Stroke Complications:** - **Multi-organ failure:** Aggressive cooling prevents this; every minute of delay worsens prognosis. - **Rhabdomyolysis:** Intense muscle breakdown from heat and exertion causes myoglobinuria; monitor urine color and CK levels; prevent acute kidney injury with aggressive hydration. - **DIC:** Severe heat stroke causes coagulopathy; monitor PT, aPTT, fibrinogen, platelets; transfuse if needed. **Hypothermia Complications:** - **Afterdrop:** Rewarm the core preferentially to prevent peripheral vasodilation and return of cold blood to the heart, which lowers core temperature further. - **VF:** Gentle handling and organized resuscitation prevent triggering VF. - **Rhabdomyolysis:** Intense shivering during rewarming causes muscle breakdown; monitor CK and myoglobin. **Submersion Injury Complications:** - **Secondary drowning:** Observe for 24 hours; educate families about delayed pulmonary edema. - **Aspiration pneumonia:** Though prophylactic antibiotics are not routine, monitor for fever and new infiltrates suggestive of infection; treat if it develops. - **Anoxic brain injury:** Prolonged hypoxia causes neurological damage; outcomes depend on duration and temperature. **Documentation and Communication:** - **Time is critical:** Document all times (time of injury, time of arrival, time of interventions, time medications given). This is essential for calculating medication doses (e.g., Parkland formula start time, NAC dosing, antivenom dosing) and for medical-legal purposes. - **Serial vitals, mental status, and physical findings:** Frequent documentation of ABCDE findings and serial reassessment shows the clinical trajectory and guides further intervention. - **Handoff to the next team:** Clearly communicate the patient's status, what interventions have been done, what the plan is, and any red flags to watch for. Example: "This 45-year-old arrived with a 30% TBSA burn 1 hour ago. Airway is intact, no stridor yet, but we intubated because of singed nasal hairs and enclosed-space fire. Parkland resuscitation ongoing; target is 0.5 mL/kg/hr urine output (35 mL/hr for this 70-kg patient). Watch for airway swelling and fluid overload. Transfer to burn center arranged." **Teaching and Prevention—A Nurse's Responsibility:** The ounce of prevention is worth a pound of cure. Post-emergency nursing includes teaching families and patients: - **Medication safety:** Store medications securely; use childproof containers; educate about poison control hotline (in the Philippines: contact the nearest hospital or Poison Control, or the National Poison Control hotline). - **Heat illness prevention:** Hydration during exercise in heat, gradual acclimatization, recognition of early signs (weakness, headache). - **Cold exposure:** Appropriate layered clothing, recognition of hypothermia signs, importance of seeking warmth. - **Water safety:** Supervision of children, use of life jackets, CPR training for caregivers, importance of removing the victim from water and beginning CPR immediately (do not wait for EMS). - **Snake and insect awareness:** In endemic areas, educate about snake avoidance, proper footwear, and the importance of seeking medical care and antivenom for bites. - **Burn prevention:** Working smoke detectors, escape plans, stop-drop-roll teaching for children, careful handling of hot liquids and flammables.