NCLEX Physiological Adaptation

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Where this fits in the test plan
Physiological Adaptation is about 14% of the items you will see. That percentage is worth taking literally when you plan revision time: a category at 14% deserves roughly 14% of your question practice, not equal time with everything else.
| Topic | Focus | Study time |
|---|---|---|
| Fluid and Electrolyte Balance high yield | Volume status and the six key electrolytes | 16 min |
| Acid-Base Balance high yield | Reading a blood gas in four steps | 12 min |
| Cardiac Disorders high yield | Coronary syndrome, heart failure and dysrhythmias | 15 min |
| Respiratory Disorders high yield | Asthma, COPD, pneumonia and pneumothorax | 14 min |
| Neurological Disorders high yield | Stroke, seizures, spinal cord and raised pressure | 15 min |
| Endocrine Disorders high yield | Diabetes, thyroid and adrenal conditions | 15 min |
| Renal and Gastrointestinal Disorders | Kidney injury, dialysis, liver and bowel disease | 15 min |
| Medical Emergencies high yield | Shock, anaphylaxis, burns and trauma | 14 min |
Fluid and Electrolyte Balance
Volume status and the six key electrolytes
Almost every electrolyte item reduces to one question: is this client too dry or too wet, and which electrolyte explains the presentation? Weight and level of consciousness are the two most useful data points.
Subtopics: Fluid volume deficit and excess · Sodium · Potassium · Calcium and magnesium · Phosphorus
Volume deficit
Tachycardia, orthostatic hypotension, dry mucous membranes, poor skin turgor, flat neck veins, concentrated urine with high specific gravity, weight loss and rising BUN with a normal creatinine.
Volume excess
Weight gain, bounding pulse, distended neck veins, crackles, oedema, dyspnoea and dilute urine. Treat with fluid and sodium restriction, diuretics and daily weights.
Sodium disorders
Hyponatraemia causes confusion, headache, nausea and seizures, and is corrected slowly. Hypernatraemia causes thirst, dry sticky membranes, restlessness and seizures, and is also corrected slowly.
Potassium disorders
Hypokalaemia gives weakness, cramps, flat T waves, U waves and increases digoxin toxicity. Hyperkalaemia gives peaked T waves, widened QRS, weakness and cardiac arrest.
Calcium and magnesium
Low levels of either cause tetany, twitching and hyperreflexia. High levels cause weakness, lethargy and lost reflexes. Magnesium must be corrected before refractory hypocalcaemia responds.
High-yield points
- Daily weight at the same time on the same scale is the most reliable fluid measure; 1 kg equals about 1 L.
- Confirm urine output before giving potassium replacement.
- Never give potassium by IV push, and never give it undiluted.
- For hyperkalaemia: calcium gluconate protects the heart, insulin with dextrose and beta agonists shift potassium into cells, and a binder or dialysis removes it.
- Salt substitutes are potassium chloride; teach clients on potassium-sparing diuretics or ACE inhibitors to avoid them.
- Trousseau and Chvostek signs indicate hypocalcaemia.
- Check deep tendon reflexes hourly during a magnesium infusion; absent reflexes mean stop the infusion.
Acid-Base Balance
Reading a blood gas in four steps
Blood gas items are free marks once the method is automatic. Look at pH, then CO2, then bicarbonate, then decide whether compensation has occurred.
Subtopics: ABG interpretation · Respiratory acidosis and alkalosis · Metabolic acidosis and alkalosis · Compensation
The method
Step one: is the pH low (acidosis) or high (alkalosis)? Step two: does the CO2 move opposite the pH? If so, respiratory. Step three: does the bicarbonate move with the pH? If so, metabolic. Step four: if the other value has also shifted, compensation is under way.
Respiratory acidosis
CO2 retention from hypoventilation: COPD, oversedation, neuromuscular weakness, airway obstruction. Treat the ventilation problem.
Metabolic acidosis
Diabetic ketoacidosis, renal failure, severe diarrhoea, lactic acidosis from shock. Kussmaul respirations are the compensation.
Metabolic alkalosis
Vomiting, prolonged nasogastric suction, excessive antacid use, diuretics. Often accompanied by hypokalaemia.
High-yield points
- ROME: Respiratory Opposite, Metabolic Equal.
- Anxiety with hyperventilation gives respiratory alkalosis with tingling and dizziness.
- Prolonged vomiting gives metabolic alkalosis; prolonged diarrhoea gives metabolic acidosis.
- A normal pH with abnormal CO2 and bicarbonate is fully compensated.
- In a chronic CO2 retainer, target an oxygen saturation of 88 to 92 percent.
- Kussmaul breathing is deep and rapid, and is the lungs compensating for metabolic acidosis.
Cardiac Disorders
Coronary syndrome, heart failure and dysrhythmias
Cardiac items reward pattern recognition: left-sided versus right-sided failure, and the immediate sequence for chest pain.
Subtopics: Acute coronary syndrome · Heart failure · Dysrhythmias · Valve disorders · Endocarditis
Left versus right heart failure
Left-sided failure backs up into the lungs: dyspnoea, orthopnoea, crackles, pink frothy sputum, paroxysmal nocturnal dyspnoea. Right-sided failure backs up into the body: peripheral oedema, distended neck veins, hepatomegaly, ascites and weight gain.
Chest pain sequence
Assess and stay with the client, obtain a 12-lead ECG, give oxygen if hypoxic, aspirin, nitroglycerin and morphine as ordered, and draw troponin. Time to reperfusion drives outcome.
Atrial fibrillation
Irregularly irregular rhythm with no discernible P waves. The major risk is embolic stroke, which is why anticoagulation matters more than rhythm alone.
Lethal rhythms
Ventricular fibrillation and pulseless ventricular tachycardia need immediate defibrillation. Asystole and pulseless electrical activity need compressions and epinephrine, never defibrillation.
High-yield points
- Report a weight gain of 1 kg in a day or 2 kg in a week in heart failure.
- Pink frothy sputum with severe dyspnoea suggests acute pulmonary oedema; sit the client upright and call for help.
- Troponin is the most specific marker of myocardial injury.
- Teach clients with angina to stop activity and take sublingual nitroglycerin, calling emergency services if pain persists after the first dose.
- After a myocardial infarction, avoid straining; a stool softener is standard.
- Prophylactic antibiotics before dental work are advised for prosthetic valves and previous endocarditis.
- Cardiac tamponade: muffled heart sounds, distended neck veins and hypotension.
Respiratory Disorders
Asthma, COPD, pneumonia and pneumothorax
Respiratory items usually ask which finding means the client is getting worse, or which oxygen delivery device fits the need.
Subtopics: Asthma and COPD · Pneumonia · Tuberculosis · Pneumothorax · Oxygen therapy
Deterioration in asthma
Wheezing that disappears without improvement is ominous, because it means air is no longer moving. A rising respiratory rate with a falling saturation and an inability to speak in sentences means severe obstruction.
COPD management
Pursed-lip breathing prolongs expiration. Target oxygen saturation is 88 to 92 percent. Small frequent high-calorie meals reduce the work of eating.
Pneumothorax
Sudden pleuritic pain, dyspnoea, absent breath sounds on the affected side. Tension pneumothorax adds tracheal deviation away from the affected side and hypotension – an emergency.
Oxygen devices
Nasal cannula delivers roughly 24 to 44 percent at 1 to 6 L/min. Simple mask 40 to 60 percent at 5 to 8 L/min. Non-rebreather up to about 90 percent. Venturi mask gives the most precise concentration.
High-yield points
- Position a client in respiratory distress upright and leaning forward.
- Rinse the mouth after every inhaled corticosteroid dose.
- Bronchodilator before corticosteroid inhaler.
- For pneumonia, encourage fluids, incentive spirometry, ambulation and coughing.
- Airborne precautions for tuberculosis continue until three consecutive negative sputum smears.
- Never leave a chest tube unit above the level of the chest.
- For a client with a tracheostomy who becomes acutely dyspnoeic, suction first, then check the tube.
Neurological Disorders
Stroke, seizures, spinal cord and raised pressure
Neurological items hinge on early recognition. A change in level of consciousness is the single most sensitive sign of neurological deterioration.
Subtopics: Stroke · Increased intracranial pressure · Seizures · Spinal cord injury · Neurodegenerative disease
Stroke recognition
Facial droop, arm weakness, speech difficulty and time of onset. Establishing the last known well time determines eligibility for thrombolysis.
Raised intracranial pressure
Earliest sign is a change in level of consciousness. Late signs are the Cushing triad of rising blood pressure with widening pulse pressure, bradycardia and irregular respirations.
Seizure care
During: protect the head, turn the client to the side, loosen clothing, time the event and never restrain or insert anything into the mouth. After: maintain the airway, orient the client and document.
Autonomic dysreflexia
In spinal cord injury at or above T6. Pounding headache, severe hypertension, flushing above the lesion. Raise the head of the bed first, then find the trigger.
High-yield points
- Keep the head of the bed at 30 degrees with the head midline for raised intracranial pressure.
- Avoid clustering care, prolonged suctioning and anything that raises intrathoracic pressure.
- Screen swallowing before giving anything by mouth after a stroke.
- Approach a client with left-sided neglect from the unaffected side initially, then teach scanning.
- Myasthenia gravis worsens with activity; Guillain-Barre ascends from the legs upward and threatens respiration.
- In Parkinson disease, a shuffling gait and freezing episodes are major fall risks.
- Never suction nasally in a client with a basilar skull fracture.
Endocrine Disorders
Diabetes, thyroid and adrenal conditions
Endocrine items are built on opposites. Learn one side of each pair thoroughly and the other side follows by inversion.
Subtopics: Diabetes and its emergencies · Thyroid disorders · Adrenal disorders · Pituitary disorders
Hypoglycaemia versus hyperglycaemia
Hypoglycaemia is fast: shaky, sweaty, tachycardic, confused. Hyperglycaemia is slower: thirst, polyuria, blurred vision, fruity breath in ketoacidosis. When unsure, treat as hypoglycaemia.
The rule of 15
For a conscious hypoglycaemic client, give 15 g of fast-acting carbohydrate, wait 15 minutes and recheck. Repeat if still low, then give a complex carbohydrate with protein.
Thyroid opposites
Hyperthyroidism speeds everything: weight loss, heat intolerance, tachycardia, tremor. Hypothyroidism slows everything: weight gain, cold intolerance, bradycardia, constipation, fatigue.
Adrenal opposites
Addison disease is under-production: hypotension, hyperkalaemia, hyponatraemia, hyperpigmentation and fatigue. Cushing syndrome is over-production: hypertension, hyperglycaemia, moon face, buffalo hump and thin skin.
High-yield points
- Never give oral carbohydrate to an unconscious client; use IV dextrose or glucagon.
- Fruity breath with Kussmaul respirations and high glucose means diabetic ketoacidosis.
- In ketoacidosis, watch potassium closely: it falls once insulin starts driving it into cells.
- Thyroid storm brings high fever, tachycardia and agitation, and is an emergency.
- After a thyroidectomy, keep a tracheostomy set at the bedside and watch for tetany from parathyroid injury.
- Addisonian crisis is treated with IV fluids, hydrocortisone and glucose.
- Never stop corticosteroids abruptly; taper them.
Renal and Gastrointestinal Disorders
Kidney injury, dialysis, liver and bowel disease
Renal items focus on output, potassium and dialysis access. Gastrointestinal items focus on bleeding, obstruction and liver failure.
Subtopics: Acute kidney injury · Chronic kidney disease and dialysis · Liver disease · Inflammatory bowel disease · Pancreatitis
Acute kidney injury phases
Onset, oliguric with rising potassium and fluid overload, diuretic with large output and electrolyte loss, then recovery. The oliguric phase carries the highest risk of hyperkalaemia.
Dialysis access
No blood pressure measurement, venipuncture or IV in the arm with a fistula. Assess for a bruit and thrill every shift; their absence means the access has clotted.
Liver failure
Ammonia rises and causes encephalopathy with asterixis. Lactulose lowers ammonia by producing soft stools. Bleeding risk rises because clotting factors fall.
Pancreatitis
Severe epigastric pain radiating to the back, relieved by leaning forward. Amylase and lipase rise. Keep nil by mouth initially and manage pain.
High-yield points
- Urine output under 30 mL per hour in an adult is reported.
- Hold potassium-containing and nephrotoxic drugs in acute kidney injury.
- Hold antihypertensives before dialysis as ordered, and weigh before and after.
- Disequilibrium syndrome after dialysis presents with headache, nausea and confusion; slow the rate and notify.
- In hepatic encephalopathy the goal is two to three soft stools a day on lactulose.
- Oesophageal varices bleed massively; avoid straining, coughing and nasogastric tube insertion without an order.
- In inflammatory bowel disease, sudden severe abdominal pain with rigidity suggests perforation or toxic megacolon.
Medical Emergencies
Shock, anaphylaxis, burns and trauma
Emergency items are the clearest application of the ABC framework. The answer is nearly always the intervention that protects airway, breathing or circulation right now.
Subtopics: Types of shock · Anaphylaxis · Burns · Trauma priorities · Poisoning
Shock types
Hypovolaemic from fluid or blood loss. Cardiogenic from pump failure. Distributive from vasodilation, including septic, anaphylactic and neurogenic. Obstructive from tamponade or massive embolism.
Anaphylaxis
Intramuscular epinephrine into the outer thigh first, then airway support and oxygen. Antihistamines and steroids are secondary.
Burns
Airway comes first with any facial burn, singed nasal hair, hoarseness or soot in the mouth. Fluid resuscitation follows a weight and body-surface-area formula, with the first half given in the first eight hours from the time of injury.
Trauma sequence
Airway with cervical spine protection, breathing, circulation with haemorrhage control, disability and exposure.
High-yield points
- Neurogenic shock is the one shock with bradycardia rather than tachycardia.
- In burns, calculate fluids from the time of injury, not from the time of arrival.
- Circumferential chest burns can restrict ventilation and may need escharotomy.
- For a chemical burn to the eye, irrigate immediately and continuously with saline or water.
- For carbon monoxide poisoning, pulse oximetry is falsely reassuring; give 100 percent oxygen.
- In hypovolaemic shock, place the client flat with legs elevated unless contraindicated, and give isotonic fluid.
- Heat stroke has hot dry skin and altered mental status and requires rapid cooling.
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