NextGen NCLEX-RN® Exam-Day Cheat Sheet & Lab Values Guide
High-yield critical laboratory ranges, emergency pharmacologic antidotes, transmission isolation protocols, nursing delegation boundaries, and acid-base compensation algorithms for the Next Generation NCLEX-RN licensure examination. Memorize these essential matrices before test day.
📌 Quick Summary / Core Test Principles:NCLEX Quick Rules: Labs: Potassium 3.5-5.0 (peaked T = Ca gluconate first!), Sodium 135-145 (max correction 8-10 mEq/24h), Calcium 8.5-10.5 (tetany/Chvostek = Ca gluconate), Magnesium 1.5-2.5 (toxicity = Ca gluconate); Antidotes: Opioid -> Naloxone; Heparin -> Protamine; Warfarin -> Vit K; Digoxin -> Digibind; MgSO4 -> Ca Gluconate; Acetaminophen -> N-acetylcysteine; Precautions: Airborne (My Chicken Hez TB) -> Negative AIIR, N95; Droplet -> Surgical mask; Contact -> Gown/gloves (C. diff = Soap and water + bleach!); Delegation: EAT (no Evaluation, Assessment, Teaching to LPN/UAP!); First ambulation / first med / unstable = RN only; ABGs: ROME (Resp Opposite, Met Equal); Cushing Triad: Widening pulse pressure, bradycardia, irregular respirations = High ICP (HOB 30 deg, head midline).
Diagnostic Laboratories
Critical Serum Laboratory Values & Panic Alert Thresholds
| Laboratory Parameter | Standard Reference Range | Panic / Critical Alert Threshold | Clinical Manifestations & Nursing Actions |
|---|---|---|---|
| Serum Potassium (K+) | 3.5 - 5.0 mEq/L | < 2.5 or > 6.5 mEq/L | Hyperkalemia: Tall peaked T waves, prolonged PR, wide QRS -> IV Calcium Gluconate first to stabilize myocardium, then insulin+D50, kayexalate, dialysis. Hypokalemia: Flattened T waves, prominent U waves, paralytic ileus, digoxin toxicity risk -> IV KCl max 10 mEq/hr peripherally; never IV push! |
| Serum Sodium (Na+) | 135 - 145 mEq/L | < 120 or > 160 mEq/L | Hyponatremia: Confusion, cerebral edema, generalized seizures -> 3% hypertonic saline with max correction rate 8-10 mEq/L/24hr (prevents osmotic demyelination). Hypernatremia: Thirst, dry mucous membranes, hallucinations -> Hypotonic fluids slowly (0.45% NS). |
| Total & Ionized Calcium (Ca++) | 8.5 - 10.5 mg/dL (Ionized: 4.5 - 5.6 mg/dL) | < 6.5 or > 13.0 mg/dL | Hypocalcemia: Chvostek's sign (facial twitch), Trousseau's sign (carpal spasm with BP cuff), laryngospasm -> IV Calcium Gluconate. Hypercalcemia: Bone pain, renal calculi, shortened QT interval, muscle flaccidity -> IV 0.9% NS hydration, furosemide, calcitonin. |
| Serum Magnesium (Mg++) | 1.5 - 2.5 mEq/L | < 1.0 or > 4.5 mEq/L | Hypomagnesemia: Hyperreflexia, tremors, Torsades de Pointes (VTach) -> IV Magnesium Sulfate. Hypermagnesemia: Loss of deep tendon reflexes (0/4), bradypnea (<12 bpm), cardiac arrest -> Stop infusion, IV Calcium Gluconate. |
| Coagulation: INR (Warfarin) | 0.8 - 1.2 (Standard) 2.0 - 3.0 (AFib/DVT) 2.5 - 3.5 (Mechanical Valve) | > 4.5 (High Bleed Risk) > 8.0 (Critical) | Antidote: Vitamin K (Phytonadione) or Prothrombin Complex Concentrate (Kcentra / FFP) for active bleeding. Teach consistent dietary vitamin K intake. |
| Coagulation: aPTT (Heparin) | 30 - 40 seconds (Control) 60 - 80 seconds (Therapeutic) | > 100 seconds | Therapeutic range is 1.5 - 2.5 times control. Antidote: Protamine Sulfate. Monitor for epistaxis, hematuria, occult blood, and heparin-induced thrombocytopenia (HIT). |
| Platelet Count | 150,000 - 400,000 /mcL | < 50,000 (Bleeding precautions) < 20,000 (Spontaneous hemorrhage) | Thrombocytopenia: Soft toothbrushes, no razors (electric only), avoid IM injections, gentle nose blowing, assess for petechiae, purpura, and drop in hematocrit. |
| Cardiac Biomarkers: Troponin I | < 0.04 ng/mL | > 0.40 ng/mL | Gold standard for myocardial necrosis. Rises in 3-4 hours, peaks in 12-24 hours, persists for 10-14 days. If ST elevation on ECG, activate cath lab immediately for PCI. |
| Therapeutic Drug: Digoxin | 0.5 - 2.0 ng/mL | > 2.0 ng/mL | Toxicity: Anorexia, nausea, yellow-green halos around lights, bradycardia, heart blocks. Potentiated by hypokalemia! Antidote: Digoxin immune Fab (Digibind). |
| Therapeutic Drug: Lithium | 0.6 - 1.2 mEq/L (Maintenance) 1.0 - 1.5 mEq/L (Acute Mania) | > 1.5 mEq/L (Mild) > 2.0 mEq/L (Severe) | Toxicity: Coarse hand tremors, ataxia, slurred speech, confusion, seizures. Precipitated by sodium depletion or dehydration (kidney retains lithium in place of sodium). |
💡 Pro Tip:NCLEX Exam Trap: When potassium is abnormal, always check the cardiac monitor first. In hyperkalemia with ECG changes (peaked T waves), Calcium Gluconate is administered FIRST to save the heart from fibrillation, before insulin or kayexalate are given to lower potassium!
Pharmacology & Reversals
High-Alert Antidotes & Emergency Medication Reversals
| Toxic Agent / Class | Mechanism of Toxicity | Specific Reversal Antidote | Administration Rules & Nursing Watch-Outs |
|---|---|---|---|
| Opioids (Morphine, Hydromorphone, Fentanyl, Oxycodone) | Mu-receptor agonism causing medullary respiratory center depression (RR < 8, miosis, coma) | Naloxone (Narcan) | Administer IV, IM, or intranasal. Half-life is 30-90 min (shorter than most opioids); monitor for recurrent sedation and respiratory depression when naloxone clears; repeat doses required! |
| Unfractionated & LMW Heparin | Antithrombin III potentiation inhibiting thrombin and factor Xa | Protamine Sulfate | Administer by slow IV push (max 50 mg in 10 min) to avoid sudden hypotension and bradycardia; 1 mg neutralizes ~100 units of heparin. |
| Warfarin (Coumadin) | Inhibition of Vitamin K Epoxide Reductase, depleting factors II, VII, IX, X | Vitamin K1 (Phytonadione) / 4-Factor PCC | Oral or slow IV phytonadione; for life-threatening intracranial hemorrhage, administer 4-factor Prothrombin Complex Concentrate (Kcentra) or FFP for immediate factor repletion. |
| Digoxin (Lanoxin) | Inhibition of Na+/K+ ATPase leading to intracellular calcium overload and lethal arrhythmias | Digoxin Immune Fab (Digibind / DigiFab) | Administer for life-threatening arrhythmias, severe hyperkalemia (>5.0 mEq/L), or massive acute ingestion (>10 mg in adults). |
| Magnesium Sulfate | Neuromuscular transmission blockade causing loss of DTRs, respiratory paralysis, and asystole | Calcium Gluconate 10% | Administer 10 mL of 10% solution (1 gram) slow IV push over 3-5 minutes. Stop magnesium immediately if patellar reflexes absent or respirations < 12/min. |
| Benzodiazepines (Lorazepam, Diazepam, Midazolam) | GABA-A receptor potentiation causing respiratory depression and profound sedation | Flumazenil (Romazicon) | Use with extreme caution in chronic benzodiazepine users or seizure disorders; rapid reversal can trigger intractable status epilepticus and severe withdrawal. |
| Acetaminophen (Tylenol / Paracetamol) | Accumulation of toxic NAPQI metabolite depleting hepatic glutathione, causing acute liver necrosis | N-Acetylcysteine (NAC / Acetadote / Mucomyst) | Most effective within 8 hours of ingestion. Given IV or orally (diluted in fruit juice due to rotten egg odor). Based on Rumack-Matthew nomogram. |
| Beta-Blockers (Metoprolol, Atenolol, Propranolol) | Profound negative inotropy, chronotropy, and refractory bradycardia/hypotension | Intravenous Glucagon | Glucagon stimulates cyclic AMP production through a non-beta-adrenergic receptor pathway, directly increasing heart rate and myocardial contractility. |
| Norepinephrine / Dopamine Extravasation (Vesicant) | Intense localized alpha-1 vasoconstriction causing ischemic tissue necrosis and gangrene | Phentolamine (Regitine) | Do not remove IV cannula immediately! Aspirate residual drug, inject phentolamine through cannula and infiltrate 5-10 mg diluted in saline subcutaneously around the blanched perimeter. |
💡 Pro Tip:NCLEX Exam Trap: Naloxone wears off FASTER than the opioid! A patient who wakes up and is alert after Narcan can slip back into fatal respiratory arrest 45 minutes later when the naloxone clears. Continued hourly monitoring is mandatory!
Infection Prevention & Control
Transmission-Based Precautions & PPE Donning/Doffing Sequence
| Precaution Category | Target Pathogens / Clinical Conditions | Barrier Requirements & Room Placement | Transport & Disinfection Protocols |
|---|---|---|---|
| Airborne Precautions (Particle size < 5 microns) | • Tuberculosis (Pulmonary/Laryngeal) • Measles (Rubeola) • Varicella-Zoster (Chickenpox / Disseminated Shingles) | • Airborne Infection Isolation Room (AIIR) with negative air pressure (6-12 air exchanges/hr) • Door strictly closed • NIOSH-certified fit-tested N95 respirator (or PAPR) before entering | • Client wears standard surgical mask when transported outside room • Susceptible staff do not enter varicella/measles rooms |
| Droplet Precautions (Particle size > 5 microns) | • Neisseria meningitidis (Meningococcal meningitis/sepsis) • Influenza & RSV • Pertussis (Whooping cough) • Diphtheria, Mumps, Rubella, Adenovirus | • Private room (or cohort with same organism) • Surgical mask required when working within 3 to 6 feet of client • Eye protection (goggles/face shield) for cough-generating care | • Door may remain open • Client wears surgical mask during transport • Dedicated patient care equipment |
| Contact Precautions (Skin-to-skin & fomites) | • MRSA & VRE (Colonization or infection) • Scabies, Pediculosis (Lice) • Herpes simplex, Impetigo • Major non-contained wound drainage • Enteric C. difficile & Norovirus | • Private room • Clean gloves upon entering room • Impervious gown for client or surface contact • Dedicated disposable equipment (stethoscope, BP cuff) | • C. DIFFICILE RULE: Wash hands with SOAP AND RUNNING WATER (alcohol rubs do NOT kill bacterial spores!) • Disinfect room surfaces with sodium hypochlorite (BLEACH) |
| PPE Donning Sequence (Putting On) | Standard sequence to ensure complete protective coverage | 1. GOWN (tie neck and waist snugly) 2. MASK or N95 RESPIRATOR (fit-check seal) 3. GOGGLES or FACE SHIELD 4. GLOVES (pull cuffs over gown wrists) | Don BEFORE entering client room; perform fit-check on N95 by breathing in and out to ensure no air leaks around perimeter. |
| PPE Doffing Sequence (Removing Safely) | Sequence from most contaminated to least contaminated to prevent self-inoculation | 1. GLOVES (most contaminated - remove first via glove-in-glove technique) 2. GOGGLES or FACE SHIELD (handle by clean headband) 3. GOWN (untie, pull forward and roll inside-out) 4. MASK / RESPIRATOR (remove by elastic ties; touch NO front surfaces!) 5. HAND HYGIENE (immediate soap/water or alcohol rub) | Doff at doorway or anteroom. N95 respirator is removed OUTSIDE the room after the door is closed! |
💡 Pro Tip:NCLEX Exam Trap: For Clostridioides difficile, alcohol hand sanitizer is INEFFECTIVE against spores. Hand hygiene MUST be performed with antimicrobial soap and water. Environmental surfaces MUST be cleaned with chlorine bleach-based sporicidal wipes!
Management of Care & Legal
RN vs LPN/VN vs UAP Scope of Practice & Delegation Matrix
| Staff Role | Legal Scope of Practice & Permitted Clinical Tasks | Prohibited Tasks (Never Delegate!) | NCLEX Decision Criteria |
|---|---|---|---|
| Registered Nurse (RN) | • Comprehensive Initial & Ongoing Assessment • Nursing Diagnoses & Nursing Care Plan Formulation • Complex Nursing Judgments & Clinical Evaluation • Initiation of Primary Client Education & Discharge Teaching • Administration of High-Risk IV Medications (IV push, chemotherapy, TPN, blood transfusions) • Triage, Clinical Prioritization & Care Coordination | The RN retains ultimate accountability for care and CANNOT delegate clinical reasoning, assessment, evaluation, or unstable client management to anyone. | Assign the most acute, unstable, or newly admitted clients to the RN. If a situation requires evaluating, teaching, or assessing, it belongs to the RN alone. |
| Licensed Practical / Vocational Nurse (LPN/VN) | • Care of STABLE clients with predictable clinical outcomes • Focused assessments & updating established data • Sterile dressing changes on established wounds • Inserting urinary Foley catheters & nasogastric tubes • Administering oral, subcutaneous, and intramuscular medications • Administering routine scheduled maintenance IV fluids (state practice act specific) • Reinforcing teaching previously initiated by the RN • Suctioning established tracheostomies & checking feeding tube residuals | • NO comprehensive initial admission assessments • NO formulating nursing care plans • NO initial primary client education • NO IV push medications or central line medications (in most states) • NO administering blood products or initiating TPN • NO care of unstable clients | Assign stable clients with chronic conditions requiring skilled, routine procedures (e.g. chronic wound dressing, Foley placement, scheduled oral meds) to the LPN. |
| Unlicensed Assistive Personnel (UAP / CNA / PCT) | • Care of STABLE clients with non-invasive routine needs • Routine Activities of Daily Living (ADLs): bathing, toileting, grooming, mouth care • Measuring and recording routine vital signs on stable clients • Measuring intake and output (I&O), emptying Foley drainage bags • Repositioning bedbound clients and applying nonskid socks • Assisting stable clients with ambulation and transfers • Feeding clients without dysphagia or aspiration risk • Collecting clean-catch urine or stool specimens | • NO nursing assessments or evaluations • NO medication administration (even OTC or topical ointments) • NO sterile procedures or sterile dressing changes • NO initial post-operative ambulation • NO feeding clients with active dysphagia or aspiration risk • NO client education or clinical advice | Delegate standardized, repetitive, routine tasks on stable clients with predictable responses where no nursing judgment is required. |
💡 Pro Tip:NCLEX Delegation Golden Rule: Remember the acronym EAT: Do not delegate Evaluation, Assessment, or Teaching to LPNs or UAPs! Also, the FIRST of anything (first ambulation after surgery, first dose of IV antibiotic, initial dressing change) belongs strictly to the RN!
Acid-Base Physiology
Arterial Blood Gas (ABG) ROME Rule & Compensation Matrix
| Acid-Base Disturbance | pH Direction | PaCO2 (Respiratory) | HCO3- (Metabolic) | Common Etiologies & Clinical Compensation |
|---|---|---|---|---|
| Respiratory Acidosis (Alveolar Hypoventilation) | pH < 7.35 (Acid) | PaCO2 > 45 mm Hg (Acid) | Normal (22-26 mEq/L) [Uncompensated] > 26 mEq/L [Compensated] | Causes: COPD exacerbation, opioid/sedative overdose, Guillain-Barré, pneumothorax, pulmonary edema, severe pneumonia. Compensation: Kidneys slowly retain HCO3- and excrete H+ over 24-72 hours. |
| Respiratory Alkalosis (Alveolar Hyperventilation) | pH > 7.45 (Alkaline) | PaCO2 < 35 mm Hg (Alkaline) | Normal (22-26 mEq/L) [Uncompensated] < 22 mEq/L [Compensated] | Causes: Acute severe anxiety/panic attack, hypoxia (early PE), high fever, mechanical ventilator over-ventilation, gram-negative sepsis. Compensation: Kidneys excrete bicarbonate. |
| Metabolic Acidosis (Bicarbonate Deficit / Acid Gain) | pH < 7.35 (Acid) | Normal (35-45 mm Hg) [Uncompensated] < 35 mm Hg [Compensated] | HCO3- < 22 mEq/L (Acid) | Causes: Diabetic Ketoacidosis (DKA), lactic acidosis (shock, sepsis), renal failure (uremia), severe watery diarrhea (bicarbonate loss). Compensation: Rapid Kussmaul respirations (hyperventilation blowing off CO2). |
| Metabolic Alkalosis (Bicarbonate Excess / Acid Loss) | pH > 7.45 (Alkaline) | Normal (35-45 mm Hg) [Uncompensated] > 45 mm Hg [Compensated] | HCO3- > 26 mEq/L (Alkaline) | Causes: Prolonged nasogastric suctioning, severe intractable vomiting, excessive antacid ingestion, loop/thiazide diuretic hypokalemia. Compensation: Hypoventilation (slow shallow breathing retaining PaCO2). |
| Compensation Determination (Stepwise Algorithm) | Evaluate pH: • < 7.35 = Acid • > 7.45 = Base • 7.35-7.45 = Normal | Evaluate PaCO2: • > 45 = Acid • < 35 = Base • 35-45 = Normal | Evaluate HCO3-: • < 22 = Acid • > 26 = Base • 22-26 = Normal | 1. Uncompensated: pH is abnormal, one parameter is abnormal, the other is completely NORMAL. 2. Partially Compensated: pH is abnormal, BOTH PaCO2 and HCO3- are abnormal in opposite directions. 3. Fully Compensated: pH is NORMAL (7.35-7.45), but BOTH PaCO2 and HCO3- are abnormal. |
💡 Pro Tip:ROME Rule: Respiratory Opposite (pH ↓, PaCO2 ↑ = Resp Acidosis; pH ↑, PaCO2 ↓ = Resp Alkalosis). Metabolic Equal (pH ↓, HCO3- ↓ = Met Acidosis; pH ↑, HCO3- ↑ = Met Alkalosis). If vomiting or NG suction, stomach acid is lost -> Metabolic Alkalosis! If severe diarrhea, base is lost -> Metabolic Acidosis!
Emergency & Critical Care
Emergency Triage (ESI), Resuscitation Formulas & Rapid Response Triggers
| Clinical Category | Assessment Finding / Trigger | Immediate Action / Formula | High-Yield NCLEX Principle |
|---|---|---|---|
| Emergency Severity Index (ESI) Triage Levels 1 - 5 | • ESI 1: Immediate life-threat (cardiac arrest, severe respiratory arrest, anaphylaxis, flail chest) • ESI 2: High risk / confusional state / severe pain (acute stroke, chest pain, testicular torsion) • ESI 3: Stable, needs >= 2 resources (labs + IV fluids) • ESI 4: Stable, needs 1 resource (X-ray or stitches) • ESI 5: Non-urgent, needs 0 resources (prescription refill) | ESI 1 = Immediate bedside resuscitation. ESI 2 = Rapid bed placement and provider evaluation within 10 minutes. ESI 3-5 = Waiting area based on resource needs. | Prioritization in mass casualty: Red (immediate life threat, salvageable), Yellow (delayed, stable serious), Green (walking wounded), Black (expectant/deceased, palliative care only). |
| Parkland Burn Formula (Thermal Burn Resuscitation) | Second-degree (partial-thickness) and third-degree (full-thickness) burns covering > 15-20% TBSA | Total 24-hr Fluid (Lactated Ringer's) = 4 mL × Weight (kg) × % TBSA burned. • Give 50% of total volume in first 8 hours FROM TIME OF BURN. • Give remaining 50% over the next 16 hours. | NCLEX Trap: The 8-hour clock starts from the TIME OF INJURY, NOT the time of hospital arrival! If burn occurred at 0800 and patient arrives at 1000, the first 50% must infuse over the remaining 6 hours! |
| Cushing's Triad (Increased ICP / Herniation) | 1. Systolic hypertension with widening pulse pressure (e.g. 190/60) 2. Bradycardia with bounding pulse (e.g. 42 bpm) 3. Irregular, bradypneic respirations (Cheyne-Stokes) | • Elevate HOB 30 degrees • Maintain head/neck in neutral midline position • Avoid hip flexion > 90 degrees • Hyperosmolar therapy (Mannitol / 3% Saline) • Avoid hyperthermia and hypoxia | Late, ominous sign of impending brainstem herniation through the foramen magnum. Do NOT place in Trendelenburg position (will cause instant brain herniation). |
| Autonomic Dysreflexia (Spinal Cord Injury T6 or above) | Sudden pounding headache, profuse diaphoresis above lesion, severe hypertension (BP > 200/100), bradycardia | 1. Immediately sit client UP at 90 degrees (high-Fowler) with legs dependent. 2. Loosen restrictive clothing. 3. Check for bladder distension / kinked catheter (most common cause, 85%). 4. Check for bowel impaction. | High-Fowler positioning uses gravity to pool blood in lower extremities, immediately lowering dangerous cerebral blood pressure. |
💡 Pro Tip:NCLEX Prioritization Hierarchy: (1) Airway, (2) Breathing, (3) Circulation, (4) Neurological / Vital sign instability. Acute problems take priority over chronic problems. Unstable patients take priority over stable patients. Unattended surgical complications take priority over expected post-op pain!