NLE Foundations of Medical-Surgical Nursing — Homeostasis, Inflammation and Cellular ResponseDetailed Explanation

Homeostasis and Stress Adaptation

Homeostasis is the body's ability to maintain a stable internal environment despite constant changes in the external world. Think of it like a thermostat in a room — when the temperature rises above the set point, the air conditioner turns on to cool it down; when it drops too low, the heater activates. The body uses similar self-correcting mechanisms to keep temperature, blood pH (7.35–7.45), blood glucose, fluid volume, and electrolytes within narrow, life-sustaining limits. The primary mechanism is the NEGATIVE FEEDBACK LOOP: a deviation from the normal set point triggers a response that brings the value back to normal. For example, a rise in blood glucose after a meal triggers insulin release, which lowers glucose — restoring homeostasis. Negative feedback is the most common type and the most important clinically. POSITIVE FEEDBACK LOOPS amplify a response away from the set point. These are less common and are normally short-lived with a definitive endpoint. Examples include: uterine contractions during labor (more stretch = more oxytocin = stronger contractions, ending at delivery) and platelet aggregation during clotting (more platelets attract more platelets, ending when the clot is formed). STRESS disrupts homeostasis. A stressor can be physiologic (trauma, infection, surgery, hemorrhage, burns) or psychological (fear, grief, anxiety). Stress activates two major systems: (1) the SYMPATHETIC NERVOUS SYSTEM, producing immediate 'fight-or-flight' responses, and (2) the HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS, producing hormonal responses. Hans Selye's GENERAL ADAPTATION SYNDROME (GAS) describes the body's nonspecific, patterned response to any stressor in three stages: 1. ALARM STAGE: The initial 'fight-or-flight' response. The hypothalamus stimulates the sympathetic nervous system, releasing catecholamines (epinephrine and norepinephrine) from the adrenal medulla, and activates the HPA axis, releasing cortisol from the adrenal cortex. Effects: increased heart rate, blood pressure, respiratory rate, blood glucose, and mental alertness; blood is shunted away from the skin and GI tract toward the heart, lungs, and skeletal muscles. This is a survival response. 2. RESISTANCE (ADAPTATION) STAGE: The body tries to adapt and return to homeostasis. If the stressor is resolved, the person recovers. If the stressor persists, the body remains in a state of heightened physiologic demand, consuming resources. 3. EXHAUSTION STAGE: If the stressor is prolonged or overwhelming, the body's adaptive reserves are depleted. This leads to physiologic decline, immune suppression, disease, and potentially death. The LOCAL ADAPTATION SYNDROME (LAS) is a localized response of a specific tissue or body part to stress — for example, the inflammatory response at a wound site, or a callus forming on the palm of a laborer. It is protective and site-specific, unlike the systemic GAS. KEY STRESS HORMONES and their clinical implications: - CORTISOL: raises blood glucose (gluconeogenesis), suppresses inflammation and immunity, promotes protein and fat catabolism. Clinical implication: postoperative patients are often hyperglycemic due to cortisol release, even without diabetes. Chronic cortisol elevation → impaired wound healing, immunosuppression. - ALDOSTERONE: promotes sodium and water retention by the kidneys → increases blood volume and blood pressure. Clinical implication: postoperative fluid retention, edema. - ADH (ANTIDIURETIC HORMONE): conserves water by the kidneys → decreased urine output. Clinical implication: oliguria in the early postoperative or post-trauma period is expected and physiologic — but must be differentiated from pathologic oliguria. This explains why a patient one day post-appendectomy may have: elevated blood glucose, decreased urine output, mild edema, and increased susceptibility to infection — all driven by the stress response hormones.

Cellular Injury and Adaptation

Cells are the basic units of life, and they constantly respond to their environment. When the level of stress or demand changes, cells adapt by altering their size, number, or type. When injury exceeds the cell's capacity to adapt, cell death occurs. Understanding these changes helps nurses recognize early signs of disease and understand the pathophysiology behind many medical conditions. CELLULAR ADAPTATIONS (reversible, protective responses): 1. ATROPHY: Decrease in cell size due to decreased workload, loss of nerve supply, decreased blood supply, inadequate nutrition, or loss of hormonal stimulation. Example: muscle wasting (muscle atrophy) in a patient who has been on bed rest for weeks, or the atrophy of a limb in a cast. Physiologic atrophy: normal involution of the thymus in early adulthood. 2. HYPERTROPHY: Increase in cell size (not number) due to increased workload or hormonal stimulation. The cell works harder and grows bigger. Example: LEFT VENTRICULAR HYPERTROPHY in a patient with chronic hypertension — the heart muscle grows bigger because it must pump against higher resistance. Another example: bicep muscle enlargement in bodybuilders. 3. HYPERPLASIA: Increase in cell NUMBER due to increased demand or hormonal stimulation. Only occurs in cells capable of mitosis (not neurons or cardiac muscle cells). Example: breast tissue growth during pregnancy; endometrial hyperplasia from excess estrogen; benign prostatic hyperplasia (BPH) in older males (common in Filipino clinical practice). 4. METAPLASIA: Reversible replacement of one mature cell type by another mature cell type that is better able to tolerate the new environment. The cells change 'occupation' to survive. Example: in chronic smokers, the normal ciliated columnar epithelium of the respiratory tract is replaced by squamous epithelium (more resistant to irritation, but loses cilia and protective function). This is REVERSIBLE if the irritant (smoking) is removed. 5. DYSPLASIA: Abnormal, disordered growth — cells vary in size, shape, and organization. Often considered PREMALIGNANT (can progress to cancer). Example: cervical dysplasia detected on Pap smear (relevant to DOH cervical cancer screening programs in the Philippines). Dysplasia is NOT a normal adaptation — it signals pathologic changes. IMPORTANT NOTE: Atrophy, hypertrophy, hyperplasia, and metaplasia are ADAPTIVE (protective, often reversible). Dysplasia is MALADAPTIVE (disordered, potentially premalignant). CAUSES OF CELLULAR INJURY: - HYPOXIA: The most common and most important cause of cell injury. Oxygen is required for ATP production via aerobic metabolism. Without it, cells switch to anaerobic metabolism → lactic acid buildup → cell death. Hypoxia can result from ischemia (most common), anemia, or impaired oxygenation. - ISCHEMIA: Inadequate blood supply (and therefore oxygen AND nutrients). More harmful than hypoxia alone. - PHYSICAL AGENTS: Trauma, extreme temperatures (burns, frostbite), radiation. - CHEMICAL AGENTS: Drugs, toxins, heavy metals. - INFECTIOUS AGENTS: Bacteria, viruses, fungi, parasites. - IMMUNE REACTIONS: Autoimmune diseases, hypersensitivity reactions. - NUTRITIONAL IMBALANCES: Malnutrition (protein deficiency), vitamin deficiencies. CELL DEATH — Two major types: 1. NECROSIS: Uncontrolled, unplanned cell death caused by external injury or disease. The cell is overwhelmed and 'explodes' — releasing its contents into the surrounding tissue, provoking INFLAMMATION. Necrosis is always PATHOLOGIC and triggers an inflammatory response. Types of necrosis: - Coagulative necrosis: most common, seen in ischemic infarcts (e.g., myocardial infarction). Cells die but maintain their shape for a time. - Liquefactive necrosis: seen in the brain and in bacterial abscesses — dead tissue liquefies. - Caseous necrosis: 'cheese-like' necrosis seen in TUBERCULOSIS — highly relevant in the Philippine setting where TB remains a major public health problem. - Gangrenous necrosis: clinically, this refers to large areas of necrosis, commonly in the extremities due to ischemia; 'wet gangrene' involves bacterial infection. 2. APOPTOSIS: Programmed, orderly, intentional cell death. The cell 'decides' to die in an organized way — it shrinks, its DNA is fragmented, and it is broken into small pieces (apoptotic bodies) that are cleanly phagocytosed WITHOUT triggering inflammation. Apoptosis is NORMAL and essential for development (e.g., the removal of webbing between fingers during fetal development), tissue homeostasis, and elimination of damaged or mutated cells. When apoptosis fails, cancer can develop (cells that should die continue to survive).

The Inflammatory Response

Inflammation is the body's NONSPECIFIC, PROTECTIVE response to ANY tissue injury or invasion — whether caused by bacteria, trauma, chemicals, burns, or necrosis. The goal of inflammation is to NEUTRALIZE and DESTROY harmful agents, LIMIT their spread to surrounding tissues, and PREPARE the injured area for HEALING. Two critical distinctions for the NLE: 1. INFLAMMATION is NOT THE SAME AS INFECTION. Inflammation is the RESPONSE; infection is ONE CAUSE of inflammation (when caused by microorganisms). A sprained ankle is inflamed but not infected. 2. Inflammation is NONSPECIFIC — it follows the same pattern regardless of the cause. The specific (adaptive) immune response involves lymphocytes, antibodies, and memory cells. VASCULAR AND CELLULAR EVENTS OF ACUTE INFLAMMATION: Upon injury, the body releases CHEMICAL MEDIATORS from damaged cells, mast cells, and plasma proteins: - HISTAMINE: Released immediately from mast cells and basophils. Causes vasodilation and increased vascular permeability. This is why antihistamines (like diphenhydramine) reduce swelling and redness. - BRADYKININ: Causes vasodilation, increased permeability, and — most importantly — PAIN. This is a key reason pain is a cardinal sign of inflammation. - PROSTAGLANDINS: Amplify vasodilation and permeability, cause PAIN sensitization, and act on the HYPOTHALAMUS to produce FEVER. NSAIDs (like ibuprofen, mefenamic acid) work by blocking prostaglandin synthesis — reducing pain, swelling, AND fever. - LEUKOTRIENES: Potent vasodilators and permeability enhancers; important in ASTHMA and allergic reactions. - CYTOKINES (TNF, IL-1, IL-6): Produced by macrophages and other cells; drive systemic inflammatory responses including fever and the acute-phase response (elevated CRP, ESR). - COMPLEMENT SYSTEM: Amplifies inflammation, promotes opsonization (tagging of bacteria for phagocytosis), and causes direct lysis of bacteria. THE VASCULAR RESPONSE occurs in sequence: 1. TRANSIENT VASOCONSTRICTION (seconds) — brief, protective. 2. VASODILATION — capillaries dilate, blood flow increases → REDNESS (rubor) and HEAT (calor). 3. INCREASED CAPILLARY PERMEABILITY — capillary walls become 'leaky,' allowing plasma proteins (especially albumin) and fluid to escape into the interstitial tissue → SWELLING/EDEMA (tumor). The fluid that accumulates is called EXUDATE (inflammatory fluid rich in protein and cells, unlike transudate which is protein-poor). THE CELLULAR RESPONSE — LEUKOCYTE MIGRATION: 1. MARGINATION: WBCs move to the edges of the capillary (line up against the endothelium). 2. DIAPEDESIS (EMIGRATION): WBCs squeeze through the capillary wall into the tissue. 3. CHEMOTAXIS: WBCs move toward the site of injury following a chemical gradient (attracted by bacterial products, complement fragments, leukotrienes). 4. PHAGOCYTOSIS: WBCs engulf and destroy debris, bacteria, and dead cells. The FIRST WBCs to arrive are NEUTROPHILS (within minutes to hours) — these are the body's first responders. They are short-lived but numerous and effective at phagocytosis. MACROPHAGES (derived from monocytes) arrive LATER and are the cleanup crew — they phagocytose debris, dead neutrophils, and foreign material, and signal the transition to healing. FIVE CARDINAL SIGNS OF INFLAMMATION (memorize these for the NLE): 1. RUBOR (Redness) — from vasodilation → increased blood flow → redness. 2. CALOR (Heat) — from increased blood flow → warmth to touch. 3. TUMOR (Swelling) — from increased capillary permeability → fluid leakage into tissue → edema. 4. DOLOR (Pain) — from pressure of edema on nerve endings AND from chemical mediators (bradykinin, prostaglandins) directly stimulating pain receptors. 5. FUNCTIO LAESA (Loss of function) — from pain and swelling limiting movement. SYSTEMIC MANIFESTATIONS OF INFLAMMATION (when inflammation is widespread or severe): - FEVER (PYREXIA): Prostaglandins (particularly PGE2) act on the HYPOTHALAMUS to raise the temperature set point. Fever inhibits bacterial replication and activates immune cells — it is PROTECTIVE in moderate degrees. - LEUKOCYTOSIS: Elevated WBC count (normal: 5,000–10,000/mm³). In acute bacterial infection, the WBC is elevated with a 'SHIFT TO THE LEFT' — meaning there is an INCREASE IN IMMATURE NEUTROPHILS (bands or stabs). This 'shift' indicates the bone marrow is releasing immature cells because demand for neutrophils has outpaced supply — a sign of serious infection. - ELEVATED ACUTE-PHASE PROTEINS: C-REACTIVE PROTEIN (CRP) and ERYTHROCYTE SEDIMENTATION RATE (ESR) rise in systemic inflammation — used as markers of inflammation in the laboratory. - MALAISE, FATIGUE, ANOREXIA: Driven by cytokines (TNF, IL-1). WOUND HEALING: Healing follows inflammation and proceeds by: - PRIMARY INTENTION: Clean, surgically approximated wound edges (surgical incision). Minimal scarring, faster healing. - SECONDARY INTENTION: Open wound (decubitus ulcer, infected wound). Healing occurs from the BASE UPWARD by GRANULATION TISSUE formation — more scarring, slower. - TERTIARY INTENTION (DELAYED PRIMARY CLOSURE): Wound is intentionally left open (e.g., infected wound), cleaned, and closed later. PHASES OF WOUND HEALING: 1. INFLAMMATORY PHASE (Days 1–4): Hemostasis followed by the classic inflammatory response. Neutrophils and macrophages cleanse the wound. 2. PROLIFERATIVE PHASE (Days 4–21): Fibroblasts synthesize COLLAGEN. New blood vessels form (ANGIOGENESIS). The wound contracts. NUTRITION IS CRITICAL here — protein (amino acids for collagen), VITAMIN C (essential for collagen cross-linking), and ZINC (cofactor for enzymes) are required. 3. MATURATION/REMODELING PHASE (Day 21 to 2 years): Collagen is remodeled and strengthened. Scar matures. FACTORS IMPAIRING HEALING: - Poor blood perfusion/oxygenation - DIABETES MELLITUS (hyperglycemia impairs leukocyte function; poor circulation) - CORTICOSTEROID USE (suppresses inflammation and immune response) - MALNUTRITION (inadequate protein, vitamin C, zinc) - INFECTION (prolongs inflammatory phase) - Older age, obesity, radiation exposure

Fluid Shifts in Illness — Third-Spacing

Under normal conditions, body fluids are distributed between the INTRACELLULAR COMPARTMENT (approximately 2/3 of body water) and the EXTRACELLULAR COMPARTMENT (approximately 1/3 — divided further into the INTRAVASCULAR space [blood plasma] and the INTERSTITIAL space [fluid between cells]). Fluid moves between compartments based on two opposing forces: 1. HYDROSTATIC PRESSURE: The 'PUSHING' force of fluid against the walls of blood vessels. When hydrostatic pressure is HIGH (e.g., in heart failure or fluid overload), it PUSHES fluid OUT of capillaries into the interstitium → EDEMA. 2. ONCOTIC (COLLOID OSMOTIC) PRESSURE: The 'PULLING' force created by plasma proteins — mainly ALBUMIN — that draw water back into the capillary. When albumin is LOW (e.g., in liver disease, malnutrition, burns, nephrotic syndrome), oncotic pressure falls → fluid is NOT pulled back → stays in the interstitium → EDEMA. Mnemonic: 'Hydrostatic PUSHES out; Oncotic PULLS in.' THIRD-SPACING: In illness, fluid can shift from the intravascular space into a 'third' space — a body compartment where it is TRAPPED and NOT READILY AVAILABLE for circulation. Common third spaces include: - INTERSTITIAL TISSUE (generalized edema) - PERITONEAL CAVITY (ASCITES — common in cirrhosis, relevant in the Philippines where alcoholic liver disease is prevalent) - PLEURAL SPACE (PLEURAL EFFUSION) - PERICARDIAL SAC (PERICARDIAL EFFUSION) - BOWEL LUMEN (in bowel obstruction) CLINICAL CONDITIONS CAUSING THIRD-SPACING: - BURNS: Massive release of inflammatory mediators → enormous increase in capillary permeability → fluid pours into burned tissue and interstitium. Classic: in the first 24 hours after a major burn, the patient develops massive edema despite having LOST intravascular volume. - SEPSIS: Systemic inflammatory mediators cause widespread capillary leak. - MAJOR ABDOMINAL SURGERY: Manipulation of bowel and peritoneum causes fluid to shift into the peritoneal cavity. - HYPOALBUMINEMIA: Low albumin (liver disease, malnutrition, nephrotic syndrome) reduces oncotic pressure → fluid stays in the interstitium. - PANCREATITIS: Inflammatory exudate shifts into the retroperitoneum and abdominal cavity. THE DANGER OF THIRD-SPACING: Although the TOTAL BODY WATER may be normal or even elevated, the INTRAVASCULAR COMPARTMENT IS DEPLETED. The patient has signs of HYPOVOLEMIA (inadequate circulating volume) DESPITE visible EDEMA: - Hypotension, tachycardia - Decreased urine output (oliguria) - Elevated hematocrit (hemoconcentration — blood is more concentrated because plasma has leaked out) - Weak, thready pulse - Pale, cool, clammy skin - Restlessness This is clinically dangerous and COUNTERINTUITIVE — the nurse sees an edematous patient and might assume the patient has 'too much fluid,' when in fact the intravascular space is CRITICALLY DEPLETED. Giving diuretics in this situation would be dangerous. FLUID REABSORPTION PHASE (Fluid Remobilization): As the patient recovers (e.g., the patient with burns is entering the DIURETIC PHASE, usually 48–72 hours after injury; postoperative patients on day 2–3), the fluid trapped in the third space is REABSORBED into the circulation. The intravascular compartment can become OVERLOADED, leading to: - Increased blood pressure - Bounding pulse - Increased urine output (diuresis) - Risk of PULMONARY EDEMA NURSING IMPLICATIONS OF THIRD-SPACING: - DAILY WEIGHTS: The most sensitive and reliable indicator of fluid balance. A 1 kg weight gain ≈ 1 liter of fluid retained. - ACCURATE INTAKE AND OUTPUT (I&O): Urine output target: ≥30 mL/hr in adults (0.5 mL/kg/hr). - MONITOR SERUM ALBUMIN: Low albumin explains edema despite hypovolemia. Target: 3.5–5.0 g/dL. - HEMODYNAMIC MONITORING: Blood pressure, pulse, CVP, and if available, pulmonary artery pressures. - LUNG AUSCULTATION: In the reabsorption phase, monitor for crackles (fluid reabsorption → overload → pulmonary edema). - DO NOT CONFUSE EDEMA WITH ADEQUATE HYDRATION: The edematous patient may STILL need IV fluids if the intravascular space is depleted.

Introduction to Shock

SHOCK is a life-threatening clinical syndrome defined as INADEQUATE TISSUE PERFUSION AND CELLULAR OXYGENATION. The fundamental problem in shock is that cells are not receiving enough oxygen to sustain normal aerobic metabolism. When oxygen delivery fails, cells switch from AEROBIC to ANAEROBIC METABOLISM → producing LACTIC ACID as a byproduct → METABOLIC ACIDOSIS develops → cellular enzymes fail → cell death → organ dysfunction → MULTIPLE ORGAN DYSFUNCTION SYNDROME (MODS) → death. The 'clock is ticking' in shock — every minute of inadequate perfusion causes irreversible cellular damage. This is why EARLY RECOGNITION and RAPID INTERVENTION are the top nursing priorities. CLASSIFICATION OF SHOCK: 1. HYPOVOLEMIC SHOCK — Most Common Type: Cause: LOSS OF CIRCULATING VOLUME - Hemorrhage (internal or external) - Dehydration (severe vomiting, diarrhea — common cause of hypovolemic shock in Filipino pediatric and adult patients) - Third-spacing (burns, sepsis) - Plasma loss (burns) Pathophysiology: ↓ Blood volume → ↓ Venous return → ↓ Cardiac output → ↓ Tissue perfusion 2. CARDIOGENIC SHOCK — The Pump Fails: Cause: the HEART cannot pump effectively - Myocardial infarction (most common cause — large area of myocardium is necrotic and non-functional) - Severe heart failure - Dysrhythmias (very rapid or very slow HR impairs cardiac output) - Myocarditis, cardiomyopathy Pathophysiology: ↓ Cardiac output → ↓ Tissue perfusion → Fluid backs up in lungs → Pulmonary edema Distinguishing feature: PULMONARY EDEMA (crackles, orthopnea) — NOT seen in hypovolemic shock. 3. DISTRIBUTIVE SHOCK — The Volume is Maldistributed: Cause: MASSIVE VASODILATION causing blood to 'pool' in the periphery, away from vital organs. Intravascular volume is NORMAL but RELATIVELY INSUFFICIENT because the container (vasculature) has expanded massively. Subtypes: - SEPTIC SHOCK: Most common distributive shock. Caused by infection (usually gram-negative bacteria releasing endotoxins). Initially presents with WARM, FLUSHED SKIN, HIGH FEVER, and BOUNDING PULSE (hyperdynamic phase). Later deteriorates with organ failure. - ANAPHYLACTIC SHOCK: Severe allergic reaction (Type I hypersensitivity). Massive histamine release → extreme vasodilation AND bronchospasm. Classic triggers: penicillin, shellfish, bee stings — all common in the Philippines. TREATMENT: EPINEPHRINE (1:1000) IM is the first-line drug. - NEUROGENIC SHOCK: Loss of sympathetic tone due to spinal cord injury at T6 or above. UNIQUE PRESENTATION: BRADYCARDIA (not tachycardia) with WARM, DRY SKIN (not cool, clammy). The body cannot respond with vasoconstriction or tachycardia because the sympathetic nervous system is disconnected below the injury level. 4. OBSTRUCTIVE SHOCK — Physical Blockade: Cause: A MECHANICAL OBSTRUCTION prevents adequate cardiac output. - CARDIAC TAMPONADE: Fluid in the pericardial sac compresses the heart. - TENSION PNEUMOTHORAX: Air in the pleural space shifts the mediastinum, compressing the great vessels. - MASSIVE PULMONARY EMBOLISM: Clot blocks pulmonary circulation, impeding right ventricular outflow. STAGES OF SHOCK (applies broadly, especially to hypovolemic shock): 1. INITIAL STAGE: - Cellular-level changes: anaerobic metabolism begins, lactic acid accumulates. - NO obvious clinical signs — the patient appears stable. - Undetectable without sensitive monitoring (e.g., serum lactate). 2. COMPENSATORY STAGE (CRITICAL WINDOW FOR INTERVENTION): - The body ACTIVATES three compensatory mechanisms: a. SYMPATHETIC NERVOUS SYSTEM: epinephrine/norepinephrine release → TACHYCARDIA, vasoconstriction, increased contractility. b. RAAS (Renin-Angiotensin-Aldosterone System): Aldosterone → sodium and water retention; Angiotensin II → vasoconstriction. c. ADH: Water retention → ↑ blood volume. - Clinical signs: TACHYCARDIA (first sign), NARROWED PULSE PRESSURE (diastolic rises due to vasoconstriction), DECREASED URINE OUTPUT, cool/clammy skin, RESTLESSNESS and ANXIETY. - CRITICAL POINT: BLOOD PRESSURE IS OFTEN STILL NORMAL at this stage because compensatory vasoconstriction maintains it. DO NOT wait for hypotension to diagnose shock. - RESTLESSNESS AND ANXIETY are often the EARLIEST SIGNS of inadequate cerebral perfusion — never dismiss them. 3. PROGRESSIVE (DECOMPENSATED) STAGE: - Compensation FAILS. The body can no longer maintain blood pressure. - Signs: HYPOTENSION (systolic < 90 mmHg or a drop of ≥40 mmHg from baseline), worsening metabolic acidosis, altered mental status (confusion, stupor), deteriorating organ function. - Positive feedback cycles worsen the situation: hypotension → ischemia → myocardial depression → worse hypotension. 4. REFRACTORY (IRREVERSIBLE) STAGE: - Profound, irreversible organ failure (brain, kidneys, liver, heart, gut). - MODS develops. - Death is inevitable despite maximal intervention. - Nursing focus shifts to comfort and family support. GENERAL CLINICAL MANIFESTATIONS OF SHOCK: - CARDIOVASCULAR: Tachycardia (except neurogenic — bradycardia), hypotension (late sign), weak thready pulse, narrowed pulse pressure. - SKIN: Cool, pale, clammy (EXCEPT early septic and neurogenic shock — warm flushed skin). - RENAL: OLIGURIA (< 30 mL/hr) — kidney hypoperfusion causes AKI. - NEUROLOGIC: Restlessness → confusion → decreased LOC → coma. - RESPIRATORY: Tachypnea (compensation for metabolic acidosis; also from anxiety and pain). PRIORITY NURSING MANAGEMENT (ABCS FIRST): A — AIRWAY: Ensure patent airway. Position to maintain airway patency. B — BREATHING: Administer HIGH-FLOW OXYGEN (non-rebreather mask at 10–15 L/min) — restoring oxygen delivery is the PRIMARY GOAL. C — CIRCULATION: - Establish LARGE-BORE IV ACCESS (2 large-bore peripheral IVs, 14–16 gauge, or central line). - Administer ISOTONIC CRYSTALLOIDS (0.9% NSS or Lactated Ringer's) for hypovolemic, septic, neurogenic, and anaphylactic shock. - BLOOD PRODUCTS for hemorrhagic shock. - Position: SUPINE WITH LEGS ELEVATED (modified Trendelenburg) to increase venous return — UNLESS contraindicated by respiratory distress or head injury. - MONITOR: vital signs (continuously), urine output (Foley catheter; target ≥30 mL/hr), level of consciousness, oxygen saturation. SPECIFIC INTERVENTIONS BY TYPE: - ANAPHYLACTIC: EPINEPHRINE 1:1000 IM (anterolateral thigh), then antihistamines and corticosteroids. - SEPTIC: IV broad-spectrum ANTIBIOTICS (within 1 hour of diagnosis), source control, vasopressors (NOREPINEPHRINE is first-line). - CARDIOGENIC: CAUTIOUS fluid administration (avoid worsening pulmonary edema), vasopressors (dopamine, norepinephrine), inotropes (dobutamine), reperfusion (thrombolytics, PCI) for MI. - NEUROGENIC: IV FLUIDS + VASOPRESSORS for hypotension; ATROPINE for bradycardia. - OBSTRUCTIVE: Treat the CAUSE — needle decompression for tension pneumothorax, pericardiocentesis for tamponade, anticoagulation/thrombolytics for pulmonary embolism.

The blood loss has decreased circulating volume → decreased venous return → decreased cardiac output. The body compensates with sympathetic activation: tachycardia, peripheral vasoconstriction (cool, clammy skin), and ADH/RAAS activation (oliguria). Blood pressure is marginally maintained. The priority is to RESTORE CIRCULATING VOLUME with fluids and blood products BEFORE the patient progresses to the progressive stage with overt hypotension and organ failure. The target urine output is ≥30 mL/hr as an indicator of adequate renal perfusion.

Normal proliferative phase begins around day 4–5 and involves fibroblast migration, collagen synthesis, and angiogenesis — all requiring adequate oxygen delivery, a functional immune response, and nutritional building blocks. Diabetes impairs all three. Corticosteroids directly suppress fibroblast activity and collagen production. The 'little pain' may reflect diabetic neuropathy — a further indicator of poor glycemic control. Early nutritional intervention and blood glucose optimization are as important as the wound dressing itself.

Septic shock is caused by the body's dysregulated response to severe infection. Bacterial endotoxins cause massive vasodilation and capillary leak, creating distributive (and also hypovolemic due to leakage) shock. Early, warm flushed skin distinguishes early septic shock from hypovolemic shock. The hour-1 bundle (blood cultures, antibiotics, fluids) is time-critical — delay in antibiotics significantly worsens mortality. Elevated lactate directs urgent resuscitation — lactate >4 mmol/L places the patient in the highest-risk category. Under RA 9173, the nurse must escalate immediately, document all actions, and implement orders promptly.

This is an excellent opportunity for patient health education (a core nursing responsibility under RA 9173). The nurse should explain: 'After surgery, your body releases hormones called cortisol, aldosterone, and ADH as part of the natural stress response. These hormones tell your kidneys to hold on to fluid — so less urine is produced. The fluid that was given through the IV also tends to move into your tissues temporarily, causing the puffiness you feel. This is normal in the first 24–72 hours after surgery. The good news is that as you recover, your body will naturally release this extra fluid through increased urination — usually around day 2 to 3. We'll monitor your urine output, weight, and lung sounds closely to make sure everything goes as expected.' This reassures the patient and promotes informed consent and partnership in care.

During the initial phase (first 24–48 hours) of major burns, aggressive fluid resuscitation was needed to compensate for massive capillary leak and third-spacing. As capillaries heal and permeability normalizes on day 2–3, the accumulated interstitial fluid returns to the bloodstream. This sudden increase in intravascular volume can overwhelm the heart and lungs — especially in elderly patients or those with pre-existing cardiac disease. The NURSE must recognize this transition and act proactively. The 4 kg weight gain confirms 4 liters of fluid returning to circulation. NANDA Diagnosis: Risk for Excess Fluid Volume related to fluid remobilization phase following major burn injury.