Cheat SheetNLE · Emergency & Critical Care NursingReal content

NLE Emergency & Critical Care Nursing — Common Medical EmergenciesCheat Sheet

Summary Concepts Notes Revision Deep Dive Slides Flashcards Mistakes Cheat Mnemonics Templates

Common Medical Emergencies cheat sheet for NLE aspirants. If you could only take one sheet of paper into your review session, this is what it would look like. Professional Regulation Commission (PRC) — Board of Nursing's most-tested concepts, all in one place.

Exam context

For the Philippine Nurse Licensure Examination (PNLE), Professional Regulation Commission (PRC) — Board of Nursing tests Emergency & Critical Care Nursing under a "Core" label, with Common Medical Emergencies in the 5th slot across 5 chapters. NLE candidates must clear the 75% weighted average with no sub-test below 60% cut on the 2026 paper, which draws about 50 Emergency & Critical Care Nursing questions. Date to watch: Bi-annual.

Common Medical Emergencies - Cheat Sheet

Your final 30-minute rapid-fire reference for recognizing and managing acute respiratory, cardiac, allergic, hypertensive, abdominal, and diabetic emergencies. This sheet covers every high-yield point, critical drug dosages, treatment sequences, and exam-critical distinctions tested on the NLE and emergency nursing exams in the Philippines.

Sections

Common Values

Value

>80 mmHg

Symbol

PaO2

Quantity

Normal PaO2 on room air

Value

<60 mmHg

Symbol

PaO2

Quantity

Critical PaO2 threshold

Value

35–45 mmHg

Symbol

PaCO2

Quantity

Normal PaCO2

Value

>50 mmHg

Symbol

PaCO2

Quantity

Respiratory failure PaCO2

Section Title

Acute Respiratory Emergencies

Important Facts

Universal signs of respiratory failure: ↑ RR, ↑ work of breathing, use of accessory muscles, restlessness/anxiety (early hypoxia), cyanosis, ↓ O2 sat, ↓ consciousness
PRIORITY positioning: High Fowler's (upright) to maximize lung expansion and reduce work of breathing
Acute asthma attack mainstays: short-acting beta-2 agonists (salbutamol/albuterol), anticholinergics (ipratropium), systemic corticosteroids
Continuous reassessment of O2 sat, work of breathing, mental status guides escalation to non-invasive ventilation or intubation
Accessory muscle use = escalating severity; prepare for intubation if patient tires
Stridor (barking cough) = upper airway obstruction; drooling/inability to swallow = impending airway loss

Key Definitions

Term

Respiratory Failure

Example

Patient with severe asthma exacerbation unable to maintain O2 sat >90% despite nebulizers.

Definition

Inability to maintain adequate oxygenation (PaO2 <60 mmHg on room air) or ventilation (PaCO2 >50 mmHg), representing a final common pathway for asthma, COPD, pneumonia, PE, and pulmonary edema.

Term

Silent Chest

Example

Asthmatic presents with no audible wheeze on auscultation; this is an emergency, not reassurance.

Definition

Absence of air movement sounds (no wheezing) in a previously wheezing patient with asthma — ominous sign indicating severe airflow obstruction and impending respiratory arrest, NOT improvement.

Term

Accessory Muscle Use

Example

Patient with COPD exacerbation retracting at suprasternal and intercostal spaces.

Definition

Recruitment of scalenes, sternocleidomastoids, and intercostal muscles (normal breathing uses diaphragm only); indicates increased work of breathing and respiratory distress.

Diagrams To Know

Respiratory distress progression: normal → tachypnea → accessory muscle use → silent chest → arrest
Flow pattern in asthma: normal → wheezing → silent chest (obstruction too severe to move air)

Common Values

Value

160–325 mg chewed

Symbol

ASA

Quantity

Aspirin loading dose

Value

0.3–0.6 mg, repeat q5 min × 3

Symbol

NTG

Quantity

Nitroglycerin SL dose

Value

2–4 mg IV, titrate q5–15 min

Symbol

Morphine

Quantity

Morphine initial dose

Value

<90 minutes

Symbol

D2B

Quantity

Door-to-PCI time target

Value

<30 minutes

Symbol

D2T

Quantity

Door-to-thrombolytic target

Value

3–4 hours post-MI (peaks 24–48 h)

Symbol

Quantity

Troponin detection window

Section Title

Acute Coronary Syndrome (ACS) & Myocardial Infarction

Important Facts

Classic ACS: crushing substernal chest pain ± radiation to arm/jaw, diaphoresis, nausea, SOB
12-lead ECG within 10 minutes — mandatory; ECG changes guide diagnosis (ST elevation, ST depression, T-wave inversion, new LBBB)
Troponin I or T elevation confirms myocardial injury; becomes detectable 3–4 hours post-infarction
MONA components: Morphine (if pain unrelieved by nitrates), Oxygen (only if O2 sat <90%), Nitroglycerin (SL, repeat q5min), Aspirin (160–325 mg, chewed)
CONTRAINDICATIONS to nitroglycerin: hypotension (SBP <90), RVI, PDE-5 inhibitor use (sildenafil, tadalafil) in past 24–48 hours
Reperfusion therapy: ST elevation on ECG = urgent PCI (preferred) or fibrinolytic (if PCI unavailable); door-to-balloon <90 min, door-to-thrombolytic <30 min
Continuous cardiac monitoring, IV access, serial troponins, and risk stratification essential
Post-MI complications: arrhythmia, cardiogenic shock, pulmonary edema, mechanical rupture, VSD, free wall rupture

Key Definitions

Term

Acute Coronary Syndrome

Example

Patient with crushing substernal chest pain radiating to left arm + diaphoresis + nausea requires 12-lead ECG within 10 minutes.

Definition

Acute myocardial ischemia from coronary artery obstruction; includes unstable angina (pain without troponin rise) and MI (with troponin elevation); requires rapid reperfusion to limit infarction.

Term

ST-Elevation MI (STEMI)

Example

ECG shows ST elevation in leads II, III, aVF (inferior STEMI); door-to-balloon time target <90 minutes.

Definition

Transmural MI with complete coronary artery occlusion; shows ST elevation ≥1 mm in contiguous leads on ECG; requires urgent reperfusion (PCI or fibrinolytics) — 'time is muscle.'

Term

MONA Protocol

Example

Hypoxic patient: O2; non-hypoxic: skip O2; all: aspirin 160–325 mg chewed + nitroglycerin SL + morphine if pain unrelieved.

Definition

Mnemonic for ACS initial management: Morphine (pain), Oxygen (if hypoxic), Nitroglycerin (vasodilation), Aspirin (antiplatelet) — applied based on clinical indicators, not rigid order.

Term

Right Ventricular Infarction (RVI)

Example

Inferior MI (ST elevation II, III, aVF) + RV involvement (ST elevation V4R); withhold nitrates, give fluids instead.

Definition

Infarction of the right ventricle (usually from RCA occlusion); characterized by hypotension with NORMAL or elevated JVP; nitroglycerin is contraindicated because RV depends on preload.

Term

Atypical ACS Presentation

Example

Elderly diabetic woman presents with shortness of breath and fatigue only; troponin elevated → NSTEMI.

Definition

In women, older adults, and diabetics: chest pain may be absent or atypical (dyspnea, jaw/epigastric pain, extreme fatigue); delay in diagnosis increases mortality.

Diagrams To Know

Coronary artery anatomy: RCA (inferior wall, RV, AV node), LAD (anterior, septum, apex), LCx (lateral, posterior, SA node)
ECG lead relationships to coronary territory: II/III/aVF (inferior/RCA), V1–V4 (anterior/LAD), V5–V6/I/aVL (lateral/LCx)

Common Values

Value

40–80 mg (higher if chronic high doses)

Symbol

Lasix

Quantity

Furosemide IV initial dose

Value

0.3–0.6 mg SL or 5–10 mcg/min IV infusion, titrate

Symbol

NTG

Quantity

Nitroglycerin SL/IV dose

Value

<18 mmHg

Symbol

PAWP

Quantity

Normal PAWP

Value

>18 mmHg

Symbol

PAWP

Quantity

Pulmonary edema PAWP threshold

Section Title

Acute Heart Failure & Pulmonary Edema

Important Facts

Classic triad of acute pulmonary edema: severe dyspnea + crackles + pink frothy sputum (or clear if mild)
Associated signs: tachycardia, tachypnea, anxiety, diaphoresis, hypotension (cardiogenic shock) or hypertension
PRIORITY nursing concept: 'Sit them up, dry them out, open them up'
Position: HIGH FOWLER'S (upright) with legs dependent to reduce venous return and optimize ventilation
Oxygen/NIPPV (CPAP/BiPAP): to improve oxygenation and reduce work of breathing
IV loop diuretic (furosemide): mainstay of fluid offloading; onset 5–10 min IV; monitor urine output closely
Vasodilators (nitroglycerin): reduce preload (venous dilation) and afterload (arterial dilation), improving cardiac output
Monitor: O2 sat, BP, HR, breath sounds, urine output, weight, signs of cardiogenic shock
Afterload reduction critical: IABP, inotropes if hypotensive; low BP limits diuretic and vasodilator use

Key Definitions

Term

Acute Decompensated Heart Failure

Example

Patient with history of MI presents acutely with severe dyspnea, PND, and crackles bilaterally — acute CHF exacerbation.

Definition

Sudden onset of dyspnea, orthopnea, and/or edema from inability of the heart to pump blood forward; results in pulmonary and/or systemic congestion.

Term

Pulmonary Edema (Cardiogenic)

Example

Patient with acute CHF: dyspneic, orthopneic, profuse sweating, crackles throughout, pink frothy expectorate.

Definition

Acute flooding of the lungs with fluid from elevated pulmonary venous pressure; characterized by severe dyspnea, pink frothy sputum, crackles, and hypoxemia.

Term

Orthopnea

Example

Patient must sleep on 3–4 pillows or in a chair to breathe; lying flat triggers dyspnea.

Definition

Dyspnea when lying flat due to increased venous return to the lungs; relieved by sitting upright; sign of elevated pulmonary venous pressure.

Diagrams To Know

Pathophysiology chain: LV dysfunction → ↑ LV end-diastolic pressure → ↑ pulmonary venous pressure → pulmonary edema
Treatment priorities: position → oxygen/NIPPV → diuretics → vasodilators → monitor response

Common Values

Value

0.3–0.5 mg of 1:1000 solution

Symbol

Epi IM

Quantity

Epinephrine IM for anaphylaxis

Value

1 mg of 1:10,000 solution (NOT for anaphylaxis)

Symbol

Epi IV

Quantity

Epinephrine IV for cardiac arrest

Value

Every 5–15 minutes as needed

Symbol

Interval

Quantity

Repeat epinephrine interval

Value

25–50 mg IV/IM (adjunct only)

Symbol

Benadryl

Quantity

Diphenhydramine dose

Value

125 mg IV (adjunct for late-phase prevention)

Symbol

Solu-Medrol

Quantity

Corticosteroid (methylprednisolone)

Section Title

Anaphylaxis

Important Facts

SINGLE priority intervention: IM epinephrine FIRST — do NOT delay for adjuncts (antihistamines, steroids)
Epinephrine dose for anaphylaxis: 0.3–0.5 mg IM of 1:1000 (0.3–0.5 mL), into anterolateral thigh (vastus lateralis)
Repeat epinephrine every 5–15 minutes if no response (hypotension, continued dyspnea, stridor)
CRITICAL DISTINCTION: Anaphylaxis ≠ cardiac arrest dosing — NOT 1 mg IV of 1:10,000 (that is for ACLS); confusing these is a dangerous error
Adjuncts (secondary, never instead of epinephrine): high-flow O2, aggressive IV fluids for hypotension, antihistamines (diphenhydramine), corticosteroids
Position: hypotensive patient supine with legs elevated; dyspneic patient more upright
Airway management: anticipate rapid airway swelling; have equipment at bedside; intubate early if stridor or oropharyngeal swelling
Watch for biphasic reaction — observe for ≥4–24 hours (some protocols); repeat epinephrine if symptoms recur
Common triggers in Philippines: antibiotics (penicillins, cephalosporins), NSAIDs, contrast dye, foods (shellfish, peanuts), insect venom, latex
Prevention: obtain detailed allergy history, use hypoallergenic gloves, have epinephrine auto-injector available for at-risk patients

Key Definitions

Term

Anaphylaxis

Example

Patient receives IV penicillin; within 2 minutes: urticaria, stridor, bronchospasm, hypotension, angioedema → anaphylaxis.

Definition

Rapidly progressive, life-threatening systemic allergic reaction from IgE-mediated mast cell degranulation; combines airway compromise, breathing difficulty, circulatory collapse, and skin/GI symptoms; onset typically within minutes of exposure.

Term

Epinephrine (Adrenaline)

Example

0.3–0.5 mg IM 1:1000 (0.3–0.5 mL of 1:1000 solution) into anterolateral thigh; repeat q5–15 min as needed.

Definition

First-line, single priority drug for anaphylaxis; alpha-adrenergic (vasoconstriction) and beta-adrenergic (bronchodilation, reduced mediator release) agonist that reverses the reaction.

Term

Biphasic Anaphylaxis

Example

Patient treated for anaphylaxis, improves; 4 hours later, hypotension and dyspnea recur despite no re-exposure.

Definition

Recurrence of anaphylactic symptoms hours after apparent recovery (typically 1–72 hours); occurs in 1–3% of cases; requires prolonged observation and repeat epinephrine dosing.

Term

Angioedema

Example

Patient with anaphylaxis develops lip and tongue swelling; intubation becomes high priority if stridor develops.

Definition

Swelling of deep dermis and subcutaneous tissues (lips, tongue, pharynx, larynx); can progress to airway obstruction if not treated urgently.

Diagrams To Know

Anaphylaxis cascade: allergen exposure → IgE-mast cell crosslink → degranulation → histamine/tryptase/heparin/kinins/leukotrienes → systemic vasodilation, bronchoconstriction, angioedema
ABCDE assessment in anaphylaxis: Airway (stridor, edema), Breathing (wheezing, dyspnea), Circulation (hypotension, shock), Disability (syncope, confusion), Exposure (rash, urticaria)

Common Values

Value

SBP >180 or DBP >120 mmHg

Symbol

BP criteria

Quantity

Hypertensive crisis threshold

Value

≤25% of baseline MAP in first hour

Symbol

Target reduction

Quantity

MAP reduction target

Value

20 mg initial, then 40–80 mg q10 min; max 220 mg

Symbol

Labetalol

Quantity

Labetalol IV dose

Value

5 mg/hr, titrate by 2.5 mg/hr q5–15 min; max 15 mg/hr

Symbol

Nicardipine

Quantity

Nicardipine IV infusion

Value

0.3–0.5 mcg/kg/min, titrate; max 10 mcg/kg/min (ICU only)

Symbol

SNP

Quantity

Sodium nitroprusside infusion

Value

70–100 mmHg

Symbol

MAP

Quantity

Normal MAP

Section Title

Hypertensive Crisis

Important Facts

KEY PRINCIPLE: lower BP gradually, NOT abruptly — rapid drops cause ischemic stroke, MI, or acute kidney injury from reduced perfusion
Target: reduce Mean Arterial Pressure (MAP) by approximately ≤25% in the first hour (exception: aortic dissection, which needs faster control)
MAP calculation: MAP = (SBP + 2×DBP) / 3; example: if SBP 200, DBP 120, MAP = (200 + 240)/3 = 147 mmHg
First-line IV agents: labetalol (combined alpha/beta blocker), nicardipine (calcium channel blocker), sodium nitroprusside (direct vasodilator, requires ICU monitoring)
Withhold or avoid: sudden nitroprusside boluses, immediate-release nifedipine (unpredictable drop), IV hydralazine monotherapy (causes reflex tachycardia)
Hypertensive urgency: oral therapy (e.g., amlodipine, ACE inhibitor, diuretic) over hours, close follow-up
Hypertensive emergency: admit to ICU, continuous IV infusion + arterial line BP monitoring, frequent neuro checks
Monitor end-organs: check urine (proteinuria, RBCs), creatinine (acute renal injury), troponin (ACS), neurologic status q15–30 min
Common causes: medication non-adherence, NSAID use, cocaine, sympathomimetics, renal disease, preeclampsia
Aortic dissection special case: target SBP <120 and HR <60 (use labetalol then nitroprusside or nicardipine)

Key Definitions

Term

Hypertensive Crisis

Example

Patient with SBP 200 mmHg and DBP 130 mmHg; distinction is whether acute stroke, MI, pulmonary edema, or encephalopathy is present.

Definition

Severely elevated blood pressure (typically SBP >180 mmHg or DBP >120 mmHg); distinguished by presence or absence of acute target-organ damage.

Term

Hypertensive Urgency

Example

Patient with known hypertension found with BP 190/125 but no headache, chest pain, dyspnea, or neuro changes → urgency, not emergency.

Definition

Severely elevated BP (SBP >180, DBP >120) WITHOUT acute target-organ damage; treated with oral antihypertensives over 24–48 hours; no emergency IV therapy needed.

Term

Hypertensive Emergency

Example

Patient with BP 220/130 + severe headache, confusion, seizures (hypertensive encephalopathy) → emergency; requires IV antihypertensives.

Definition

Severely elevated BP WITH acute target-organ damage (encephalopathy, ACS, acute pulmonary edema, aortic dissection, AKI, acute stroke); requires controlled IV antihypertensive therapy.

Term

Hypertensive Encephalopathy

Example

Patient with uncontrolled HTN, severe headache, confusion, seizure activity; MRI shows cerebral edema; treated with IV labetalol/nicardipine.

Definition

Acute cerebral dysfunction from severe hypertension causing cerebral edema; presents with headache, confusion, visual disturbances, seizures, altered consciousness; rapidly reversible with controlled pressure reduction.

Diagrams To Know

Autoregulation curve: cerebral blood flow maintained at MAP 50–150 mmHg; outside this range, ischemia (low) or edema (high) occurs
Hypertensive crisis decision tree: SBP >180/DBP >120 → assess for target-organ damage (neuro, cardiac, renal, pulmonary) → urgency vs emergency → oral vs IV therapy

Reactions Or Equations

Note

For hypertensive emergency, calculate baseline MAP and target MAP (baseline MAP − 25% of baseline MAP); titrate IV antihypertensives to this target.

Equation

MAP = (SBP + 2×DBP) / 3

Conditions

Standard calculation for mean arterial pressure

Common Values

Value

Soft, non-tender, no rebound, no guarding, normal BS

Symbol

Normal

Quantity

Normal abdominal exam

Value

Rigid, board-like, rebound tenderness, guarding present

Symbol

Acute

Quantity

Acute abdomen indicator

Value

One-third distance from anterior superior iliac spine to umbilicus (classic appendicitis site)

Symbol

RLQ landmark

Quantity

McBurney's point location

Section Title

Acute Abdomen

Important Facts

Red flags: severe pain, rigid (board-like) abdomen, rebound tenderness, guarding, distension, hypotension, fever, elevated WBC
PRIORITY nursing actions: keep NPO (nothing by mouth) for possible surgery, establish IV access, give IV fluids, assess pain continuously, prepare for diagnostics (CT, US, labs)
CRITICAL — DO NOT apply heat, give laxatives/enemas, or use aggressive massage — these can rupture inflamed organs (e.g., appendix) and cause peritonitis
Insert nasogastric tube if ordered for decompression in bowel obstruction; monitor NG output (character, volume)
Avoid opioid analgesia only per protocol (some institutions allow judicious analgesia AFTER surgical evaluation) — do not mask the clinical picture inappropriately
Bowel obstruction signs: severe crampy pain, vomiting, abdominal distension, high-pitched bowel sounds (early) or silent (late), visible peristaltic waves
Ruptured AAA presentation: sudden severe abdominal/back pain, hypotension, pulsatile abdominal mass, shock — mortality high; requires immediate vascular surgery
Ectopic pregnancy rupture: young woman with amenorrhea, sudden severe lower abdominal pain, shoulder pain, hemodynamic instability, ↓ Hgb
Appendicitis: RLQ pain (often begins periumbilical then localizes), nausea, fever; McBurney's point tenderness, rebound > direct tenderness (McBurney's is more painful)
Monitor vital signs closely; shock (hypotension, tachycardia, altered mental status) indicates need for emergency surgery

Key Definitions

Term

Acute Abdomen

Example

Patient with sudden severe epigastric pain, rigid abdomen, hypotension → ruptured peptic ulcer or AAA; requires urgent surgical consultation.

Definition

Sudden onset of severe abdominal pain potentially indicating a surgical emergency; includes appendicitis, perforation (peptic ulcer, viscus), bowel obstruction, mesenteric ischemia, ruptured ectopic pregnancy, and ruptured AAA.

Term

Peritonitis

Example

Perforated appendix leads to peritonitis: severe pain, fever, rigid board-like abdomen, hypotension, tachycardia.

Definition

Inflammation/infection of the peritoneum; presents with severe abdominal pain, rigidity, guarding, rebound tenderness, fever, elevated WBC; can progress to septic shock and death if untreated.

Term

Rebound Tenderness

Example

Examiner presses RLQ, patient tolerates; on sudden release, patient winces in pain — positive rebound tenderness.

Definition

Sharp pain on rapid release of palpating hand (pain is worse when letting go than when pressing); indicates peritoneal irritation and visceral perforation.

Term

Guarding

Example

Rigid, board-like abdomen that does not relax even with deep breathing; indicates serious pathology requiring urgent evaluation.

Definition

Involuntary contraction of abdominal wall muscles during palpation; sign of peritoneal irritation; distinguishes from voluntary guarding (patient tenses muscles).

Diagrams To Know

Acute abdomen assessment: pain character/location → peritoneal signs (rebound, guarding, rigidity) → organ-specific signs → imaging/labs → surgical consult
Bowel obstruction chain: mechanical block → proximal bowel dilation → vomiting → dehydration → shock → perforation/peritonitis

Common Values

Value

<70 mg/dL (3.9 mmol/L)

Symbol

Quantity

Hypoglycemia threshold

Value

15 g fast-acting carbohydrate

Symbol

Carbs

Quantity

Rule of 15 carb dose

Value

15 minutes

Symbol

Time

Quantity

Rule of 15 recheck interval

Value

25 g (50 mL of D50)

Symbol

Dextrose

Quantity

IV dextrose 50% dose

Value

1 mg (0.3–1 mg); onset 5–15 min

Symbol

Glucagon

Quantity

IM glucagon dose

Section Title

Hypoglycemia

Important Facts

Hypoglycemia is MORE immediately dangerous than hyperglycemia — brain dies within minutes of severe glucose deficit
Rapid onset distinguishes hypoglycemia from DKA/HHS (which are gradual, hours to days)
Early signs: adrenergic (tremor, diaphoresis, palpitations, anxiety, hunger) — patient usually still alert and able to communicate
Late signs: neuroglycopenic (confusion, slurred speech, altered behavior, seizures, coma) — patient at risk of injury
CRITICAL: NEVER give oral carbohydrate to unconscious or unalert patient — aspiration risk is fatal; use IV dextrose or IM glucagon
Conscious patient protocol (Rule of 15): 15 g fast-acting carbs (glucose tablets, juice, hard candy, honey) → wait 15 min → recheck → repeat if <70 → then complex carb (bread, crackers, protein)
Unconscious/unable-to-swallow protocol: IV dextrose 25 g (50 mL of D50) or IM glucagon 1 mg (onset 5–15 min, lasts 60–90 min); follow with oral carbs when alert
Glucagon is less effective in depleted glycogen stores (starvation, ethanol abuse); if no response to first dose, use IV dextrose
After hypoglycemia episode: review cause (missed meal, overdose, excessive exercise), adjust diet or insulin dose, educate on prevention
Patient should carry glucose source at all times; wear medical alert identification; teach family to recognize and treat hypoglycemia

Key Definitions

Term

Hypoglycemia

Example

Diabetic patient on insulin misses lunch; develops shakiness, sweating, confusion within 30 minutes.

Definition

Blood glucose <70 mg/dL (3.9 mmol/L); acute onset (minutes) from insulin excess, missed meals, or strenuous exercise; brain is glucose-starved and symptomatic.

Term

Adrenergic Symptoms

Example

Patient feels shaky, sweaty, heart racing, hungry — classic adrenergic response to low blood glucose.

Definition

Early signs of hypoglycemia from sympathetic nervous system activation: tremor, sweating, tachycardia, palpitations, anxiety, hunger.

Term

Neuroglycopenic Symptoms

Example

Diabetic patient found confused, combative, slurred speech, no response to commands — severe neuroglycopenia.

Definition

Later signs of hypoglycemia from direct brain glucose deprivation: confusion, irritability, slurred speech, altered behavior, seizures, loss of consciousness.

Term

Rule of 15

Example

Glucose 55 mg/dL: give 15 g glucose tablets or juice, recheck in 15 min; if still <70, repeat; once >70, eat crackers/bread to sustain.

Definition

Hypoglycemia treatment protocol for conscious patient: give 15 g fast-acting carbohydrate, wait 15 minutes, recheck glucose; repeat if still low; then give complex carb to prevent recurrence.

Diagrams To Know

Hypoglycemia symptom progression: normal → adrenergic (tremor, sweat) → neuroglycopenic (confusion) → seizure → coma → death
Hypoglycemia treatment algorithm: conscious & alert → Rule of 15 (oral carbs) vs unconscious/altered → IV dextrose or IM glucagon

Common Values

Value

>250 mg/dL (often 300–600)

Symbol

Quantity

DKA diagnostic BG

Value

<7.3 (severe <7.1)

Symbol

Quantity

DKA diagnostic pH

Value

<15 mEq/L (severe <10)

Symbol

HCO3

Quantity

DKA diagnostic HCO3

Value

1 L in first hour, then 0.5 L/hr for first 4 hr, then 0.25 L/hr

Symbol

Fluids

Quantity

IV normal saline rate

Value

0.05–0.1 units/kg/hr; target BG drop 50–75 mg/dL/hr

Symbol

Insulin

Quantity

IV regular insulin infusion

Value

If K+ <5.5 mEq/L, add KCl 20–40 mEq/L to IV fluids after urine output confirmed

Symbol

K+ replacement

Quantity

Potassium replacement threshold

Value

Add D5 or D10 when BG reaches 200–250 mg/dL

Symbol

Dextrose trigger

Quantity

Dextrose switch glucose

Value

>600 mg/dL (often 800–1200)

Symbol

BG HHS

Quantity

HHS diagnostic BG

Value

>320 mOsm/kg

Symbol

Osmolality

Quantity

HHS osmolality

Section Title

Diabetic Ketoacidosis (DKA)

Important Facts

DKA onset is GRADUAL (hours to days) — distinguishes it from rapid-onset hypoglycemia
Classic DKA triad: hyperglycemia (BG >250 mg/dL, often 300–600), metabolic acidosis (pH <7.3, HCO3 <15), positive serum and urine ketones
Classic presentation: polydipsia, polyuria, nausea, abdominal pain, Kussmaul respirations, fruity/acetone breath odor, altered consciousness
Total-body potassium is DEPLETED in DKA despite normal serum K+ — insulin shifts K+ into cells, causing dangerous hypokalemia as treatment begins
PRIORITY management sequence: (1) FLUIDS FIRST — aggressive IV normal saline to correct severe volume deficit (often 5–10 L); (2) INSULIN — IV regular insulin infusion (not bolus) to shut off ketogenesis; (3) POTASSIUM — monitor K+ closely, replace if <5.5 mEq/L before starting insulin, then add to IV fluids once insulin is infusing
DO NOT start insulin if serum K+ is severely low (<3.0 mEq/L) — will cause cardiac arrhythmias; replace K+ first
Add dextrose (D5 or D10) to IV fluids once glucose falls to 200–250 mg/dL to prevent hypoglycemia while acidosis resolves
Insulin dose: 0.05–0.1 units/kg/hr IV infusion; titrate to lower BG by 50–75 mg/dL/hr (not faster)
Monitor: BG q1h, VBG/ABG for pH/HCO3, electrolytes (especially K+) q2–4h initially, urine output, mental status, signs of cerebral edema
Cerebral edema risk: young patients, severe acidosis, rapid correction — manifests as altered consciousness, seizures; mortality >50% if occurs
Precipitants: missed insulin, infection (UTI, pneumonia), MI, new-onset diabetes, stress; always investigate cause
HHS management identical to DKA (fluids → insulin → K+) but mortality higher due to severe dehydration and older age; slower glucose correction needed

Key Definitions

Term

Diabetic Ketoacidosis

Example

Type 1 diabetic forgets insulin; presents with BG 450 mg/dL, pH 7.15, HCO3 10, positive ketones, Kussmaul respirations.

Definition

Life-threatening hyperglycemic emergency, mostly in type 1 diabetes; caused by absolute or relative insulin deficiency → fat breakdown → ketoacid accumulation → metabolic acidosis (pH <7.3, HCO3 <15 mEq/L).

Term

Ketoacidosis

Example

Insulin-deficient patient: lipolysis → free fatty acids → ketone production → ↑ ketones in blood → acidosis.

Definition

Metabolic acidosis from accumulation of ketoacid anions (beta-hydroxybutyrate, acetoacetate) in blood; lowers pH and HCO3.

Term

Kussmaul Respirations

Example

DKA patient breathing deeply and rapidly (RR 30+) even at rest; fruity/acetone smell on breath.

Definition

Deep, rapid, labored breathing (apparent hyperventilation) as respiratory compensation for metabolic acidosis; patient attempts to blow off CO2 to raise pH.

Term

Osmotic Diuresis

Example

DKA patient: polyuria (frequent urination), polydipsia (excessive thirst), profound dehydration, orthostatic hypotension.

Definition

Glycosuria (glucose in urine) because glomerular filtration exceeds renal reabsorption threshold; glucose acts as osmotic diuretic → polyuria, polydipsia, severe dehydration.

Term

Hyperosmolar Hyperglycemic State (HHS)

Example

Type 2 diabetic, elderly, presents with BG 800 mg/dL, normal pH, minimal ketones, severely dehydrated.

Definition

Hyperglycemic emergency in type 2 diabetes; extreme hyperglycemia (often >600 mg/dL) with severe dehydration, minimal/absent ketosis, and hyperosmolarity; mortality higher than DKA.

Diagrams To Know

DKA pathophysiology: insulin deficiency → gluconeogenesis, lipolysis → ↑ BG, ↑ ketones → metabolic acidosis → Kussmaul respirations → osmotic diuresis → severe dehydration → shock
DKA management flowchart: fluids → lab assessment (BG, K+, HCO3, pH) → start insulin (after K+ >3.0) → add dextrose when BG 200–250 → monitor q1–2h → resolution when pH >7.3, HCO3 >15, patient eating

Must Remember

Rank

Critical Point

SILENT CHEST IN ASTHMATIC = OMINOUS SIGN OF IMPENDING RESPIRATORY ARREST, NOT IMPROVEMENT. Absence of wheeze means obstruction is so severe that air cannot move; patient is critically ill and needs immediate intubation preparation.

Rank

Critical Point

ANAPHYLAXIS EPINEPHRINE: 0.3–0.5 mg IM (1:1000) into thigh; CARDIAC ARREST EPINEPHRINE: 1 mg IV (1:10,000). CONFUSING THESE IS A DANGEROUS ERROR. Anaphylaxis is IM first-line; cardiac arrest is IV.

Rank

Critical Point

ACUTE CORONARY SYNDROME: 12-LEAD ECG WITHIN 10 MINUTES is mandatory. MONA (Morphine, Oxygen if hypoxic, Nitroglycerin, chewed Aspirin 160–325 mg). WITHHOLD NITRATES IF: hypotensive (SBP <90), RV infarction, or PDE-5 inhibitor use (sildenafil, tadalafil) in past 24–48 hours.

Rank

Critical Point

ACUTE PULMONARY EDEMA PRIORITY: SIT THEM UP (high Fowler's), OXYGEN/NIPPV, GIVE IV FUROSEMIDE, GIVE VASODILATORS (nitroglycerin). This sequence directly reverses the pathophysiology.

Rank

Critical Point

HYPERTENSIVE EMERGENCY PRINCIPLE: LOWER BP GRADUALLY (≤25% MAP reduction in first hour), NEVER ABRUPTLY. Rapid pressure drops cause ischemic stroke, MI, or AKI from reduced organ perfusion. Requires ICU monitoring with arterial line.

Rank

Critical Point

HYPOGLYCEMIA IS MORE IMMEDIATELY DANGEROUS THAN HYPERGLYCEMIA. Rapid onset (minutes); brain dies from glucose deprivation. RULE OF 15 for conscious patients: 15 g fast carbs → wait 15 min → recheck → repeat if low → then complex carb. NEVER oral carbs if unconscious (aspiration).

Rank

Critical Point

DKA MANAGEMENT SEQUENCE: (1) FLUIDS FIRST (aggressive IV normal saline), (2) INSULIN (IV regular infusion, NOT bolus), (3) POTASSIUM (monitor closely; total body K+ is depleted; do NOT start insulin if K+ <3.0). Onset is GRADUAL (hours–days), not rapid.

Rank

Critical Point

ACUTE ABDOMEN CRITICAL DO-NOTs: NO HEAT, NO LAXATIVES, NO ENEMAS — these can rupture inflamed organs (appendix) and cause peritonitis. Keep NPO for possible surgery; establish IV access; monitor pain and vitals; prepare for urgent imaging/consult.

Rank

Critical Point

ANAPHYLAXIS: EPINEPHRINE IS THE SINGLE PRIORITY DRUG. Give IM immediately — do NOT delay for antihistamines or steroids (these are adjuncts only). Watch for BIPHASIC REACTION (recurrence hours later); observe for ≥4–24 hours; anticipate airway swelling.

Rank

Critical Point

DIABETIC EMERGENCIES DISTINCTION: HYPOGLYCEMIA (rapid, <70 mg/dL, adrenergic/neuroglycopenic symptoms) vs. DKA (gradual, BG >250, acidosis, Kussmaul respirations, fruity breath) vs. HHS (gradual, BG >600, type 2, severe dehydration, minimal ketosis). Treatment pathways differ completely.

Last Minute Tips

Tip Text

For any chest pain or ACS suspicion: 12-LEAD ECG WITHIN 10 MINUTES. This single test determines if the patient needs urgent reperfusion (PCI or fibrinolytics). Delays in ECG = delays in life-saving therapy. Mark the time on the ECG.

Tip Title

ECG Timing in ACS

Tip Number

Tip Text

MEMORIZE: Anaphylaxis = 0.3–0.5 mg IM of 1:1000 epinephrine (0.3–0.5 mL). Cardiac arrest = 1 mg IV of 1:10,000 (10 mL). These are tested frequently and confusion is dangerous. Use mnemonics: 'Thigh is 1:1000' (anaphylaxis, IM), 'Vein is 1:10,000' (arrest, IV).

Tip Title

Anaphylaxis Dosing: Write It Down

Tip Number

Tip Text

For conscious diabetic with hypoglycemia: RULE OF 15 is gold standard on NLE exams. 15 g carbs → 15 min wait → recheck → repeat if <70 → then complex carb. If unconscious: IV dextrose or IM glucagon (NEVER oral). This distinction is tested frequently.

Tip Title

Rule of 15 for Hypoglycemia

Tip Number

Tip Text

When a patient presents with acute severe abdominal pain: (1) assess peritoneal signs (rebound, guarding, rigidity), (2) keep NPO immediately, (3) establish IV, (4) do NOT apply heat/laxatives/enemas, (5) notify physician/surgeon stat. Do not delay imaging or surgical consult waiting for 'perfect' diagnosis.

Tip Title

Acute Abdomen Assessment Sequence

Tip Number

Tip Text

MAP = (SBP + 2×DBP) / 3. For hypertensive emergency with IV antihypertensives, calculate baseline MAP and reduce by ≤25% in first hour. This prevents over-correction. Example: Baseline MAP 147 → target MAP drop to 110. Arterial line monitoring is essential for accurate, continuous BP measurement.

Tip Title

Hypertensive Emergency: Know MAP Math

Tip Number

Comparison Tables

Rows

Values

Type 1 or 2 (on insulin/sulfonylurea)
Type 1 (absolute insulin deficit)
Type 2 (relative insulin deficit)

Property

Type of diabetes

Values

<70 mg/dL
250–600 mg/dL (usually >250)
>600 mg/dL (often 800–1200)

Property

Blood glucose

Values

RAPID (minutes)
GRADUAL (hours–days)
GRADUAL (days–weeks)

Property

Onset

Values

Normal
<7.3, HCO3 <15 (acidosis)
Normal or slightly ↓ (no ketosis)

Property

pH/HCO3

Values

Negative or trace
Strongly positive (serum & urine)
Negative or trace

Property

Ketones

Values

No
YES (characteristic)
No (but tachypnea)

Property

Kussmaul respirations

Values

Normal
Fruity/acetone (ketones)
Normal

Property

Breath odor

Values

Tremor, sweating, anxiety, confusion, seizures, coma
Polydipsia, polyuria, N/V, abdominal pain, altered mental status
Severe dehydration, altered mental status, weakness

Property

Key symptoms

Values

High if prolonged/severe
1–5% with treatment
5–15% (higher than DKA)

Property

Mortality

Values

Fast-acting carbs (Rule of 15) or IV dextrose/IM glucagon
Fluids → Insulin → Potassium
Fluids → Insulin → Potassium (same as DKA)

Property

PRIORITY treatment

Values

Brain starved within minutes; seizures, coma, death
Cerebral edema risk; metabolic acidosis; shock
Severe dehydration; osmotic complications; stroke/MI risk

Property

Critical danger

Columns

Feature
Hypoglycemia
DKA
HHS

Table Title

Hypoglycemia vs. Diabetic Ketoacidosis (DKA) vs. Hyperosmolar Hyperglycemic State (HHS)

Rows

Values

Crushing substernal, radiates arm/jaw
May be absent or atypical (dyspnea, jaw pain, epigastric discomfort)
—

Property

Chest pain

Values

Diaphoresis, nausea, SOB, anxiety
Extreme fatigue, weakness, SOB only
—

Property

Associated symptoms

Values

Standard
HIGHER (delayed diagnosis)
—

Property

Mortality risk

Values

If pain persists after NTG
Same; may mask atypical presentation
2–4 mg IV, titrate q5–15 min

Property

Morphine use

Values

Only if SpO2 <90%
Only if SpO2 <90%
Only if hypoxic (no benefit if normoxic)

Property

Oxygen use

Values

0.3–0.6 mg SL, repeat q5 min
Same
0.3–0.6 mg SL; AVOID if RVI, hypotensive, or PDE-5 inhibitor use

Property

Nitroglycerin use

Values

160–325 mg chewed ASAP
Same
Chewed (faster absorption than swallowed)

Property

Aspirin use

Columns

Aspect
Classic Presentation
Atypical Presentation (Women/Elderly/Diabetic)
MONA Intervention

Table Title

Acute Coronary Syndrome (ACS) Presentation & Interventions

Rows

Values

Epinephrine (adrenaline)
Epinephrine (adrenaline)

Property

Drug

Values

1:1000 (1 mg/mL)
1:10,000 (0.1 mg/mL)

Property

Concentration

Values

INTRAMUSCULAR (IM) into anterolateral thigh
INTRAVENOUS (IV)

Property

Route

Values

0.3–0.5 mg IM (0.3–0.5 mL of 1:1000)
1 mg IV (10 mL of 1:10,000)

Property

Dose

Values

Every 5–15 minutes as needed
Every 3–5 minutes (cardiac arrest protocol)

Property

Repeat interval

Values

FIRST intervention — do NOT delay
After airway/breathing established

Property

Priority timing

Values

CONFUSING with cardiac arrest dose = DANGEROUS ERROR; will cause overdose or underdose
CONFUSING with anaphylaxis dose = DANGEROUS ERROR; will cause overdose or underdose

Property

CRITICAL ERROR

Columns

Criterion
Anaphylaxis
Cardiac Arrest (ACLS)

Table Title

Anaphylaxis vs. Cardiac Arrest: Epinephrine Dosing (CRITICAL)

Rows

Values

SBP >180 or DBP >120 mmHg
SBP >180 or DBP >120 mmHg

Property

BP level

Values

ABSENT — no acute neuro, cardiac, renal, or pulmonary damage
PRESENT — acute stroke, MI, pulmonary edema, encephalopathy, AKI

Property

Target-organ damage

Values

Outpatient or ED observation; no ICU required
ICU admission mandatory

Property

Treatment setting

Values

ORAL antihypertensives (amlodipine, ACE-I, diuretic)
IV antihypertensive infusion (labetalol, nicardipine, nitroprusside)

Property

Therapy type

Values

Lower BP over 24–48 hours; gradual reduction
Controlled reduction; target ≤25% MAP decrease in 1st hour

Property

Time frame

Values

Standard: BP check q1–4h
Continuous: arterial line, frequent neuro checks q15–30 min

Property

Monitoring

Values

Low — less aggressive therapy
HIGH — can cause ischemic stroke, MI, AKI if over-corrected

Property

Risk of rapid drop

Values

Known HTN, BP 190/125, no symptoms → take to urgent care, start oral meds
BP 220/130 + severe headache + seizures (encephalopathy) → ICU, IV antihypertensives, arterial line

Property

Example

Columns

Feature
Hypertensive Urgency
Hypertensive Emergency

Table Title

Hypertensive Urgency vs. Hypertensive Emergency

Rows

Values

SOB with exertion, tachypnea (RR 20–24), able to speak in full sentences
Mild increase; diaphragm working
Alert, cooperative
Oxygen, upright positioning, assess cause

Property

Early dyspnea

Values

SOB at rest, tachypnea (RR 25–40), nasal flaring, able to speak short phrases only
Moderate increase; accessory muscles engaged (intercostal, suprasternal retractions)
Alert but anxious
High-flow oxygen, prepare for NIPPV (CPAP/BiPAP), nebulizer, labs

Property

Moderate distress

Values

Severe SOB, tachypnea (RR >40), stridor or wheeze, cannot speak (only words)
Severe; accessory muscles + diaphragmatic fatigue; tripod positioning
Anxious, restless, early hypoxia confusion
High-flow O2, NIPPV or prepare for intubation, IV access, medication boluses

Property

Severe distress

Values

SILENT CHEST (no air movement), RR ↓ (patient tiring), cyanosis, decreased response
DECREASED work — this is BAD (not good), muscle fatigue
Confused, drowsy, decreased consciousness
IMMEDIATE intubation, bag-valve-mask ventilation, epinephrine, ACLS protocol

Property

Respiratory fatigue/impending arrest

Columns

Stage
Signs & Symptoms
Work of Breathing
Mental Status
PRIORITY Intervention

Table Title

Respiratory Distress Progression & Recognition

Loading diagram…

Previous chapter

Trauma, Poisoning & Environmental Emergencies

Ready to practise for the NLE 2026?

Super Tutor's AI review plan adapts to your weak areas and builds a weekly practice schedule around your target NLE exam date.

Start free See the full NLE guide NLE preparation guide

← Back to Emergency & Critical Care Nursing hub