AACN Acute Care Exam High-Yield Review

Vocabulary practice flashcards covering critical acute care topics from the AACN Study Guide, including cranial nerves, neurology, cardiovascular disease, respiratory failure, endocrinology, hematology, and high-yield board pearls.

CN I (Olfactory Nerve)

Sensory cranial nerve responsible for smell; assessed by having the patient identify common scents; damage or dysfunction leads to anosmia.

CN II (Optic Nerve)

Sensory cranial nerve that mediates vision; evaluated with a Snellen chart and visual field testing; commonly affected by optic neuritis in multiple sclerosis.

CN III (Oculomotor Nerve)

Motor cranial nerve controlling upward, downward, and medial extraocular eye movements as well as pupillary constriction; injury causes ptosis, pupillary dilation, and a down-and-out eye deviation.

CN IV (Trochlear Nerve)

Motor cranial nerve that innervates the superior oblique muscle to direct the eye downward and inward; dysfunction results in vertical diplopia.

CN V (Trigeminal Nerve)

Mixed cranial nerve responsible for facial sensation across the forehead, cheeks, and jaw, as well as the muscles of mastication; clinical pathology includes trigeminal neuralgia.

CN VI (Abducens Nerve)

Motor cranial nerve controlling lateral eye movement via the lateral rectus muscle; damage prevents eye abduction and causes medial drifting.

CN VII (Facial Nerve)

Mixed cranial nerve controlling facial expression and taste sensation on the anterior $2/3$ of the tongue; acute unilateral lower motor neuron palsy produces Bell's palsy.

CN VIII (Vestibulocochlear Nerve)

Sensory cranial nerve mediating auditory function and vestibular balance; tested via the whisper test, Rinne/Weber tests, and Romberg maneuver; lesions produce hearing loss, vertigo, and nystagmus.

CN IX (Glossopharyngeal Nerve)

Cranial nerve responsible for swallowing, taste on the posterior $1/3$ of the tongue, and sensory input for the gag reflex.

CN X (Vagus Nerve)

Cranial nerve controlling symmetric palate elevation, vocal cord movement, gag reflex motor response, and visceral parasympathetic innervation; palsy produces hoarseness and uvular deviation.

CN XI (Spinal Accessory Nerve)

Motor cranial nerve innervating the sternocleidomastoid and trapezius muscles; assessed by shoulder shrug and head turning against resistance.

CN XII (Hypoglossal Nerve)

Motor cranial nerve controlling tongue movements; unilateral injury causes the protruded tongue to deviate toward the side of the lesion.

tPA Exclusion Criteria (Acute Ischemic Stroke)

Contraindications to intravenous alteplase including stroke or severe head trauma within the prior $3$ months, blood pressure $> 185/110\,\text{mmHg}$, active internal bleeding, INR $> 1.7$, or platelet count $< 100{,}000/\mu\text{L}$.

ABCD2 Score

Clinical risk-stratification score used after a transient ischemic attack (TIA) to predict subsequent stroke risk based on Age, Blood pressure, Clinical features, Duration of symptoms, and Diabetes.

Status Epilepticus

Continuous seizure activity lasting $> 5\,\text{minutes}$ or two or more distinct seizures without full recovery of consciousness between episodes; managed sequentially with lorazepam, phenytoin/fosphenytoin, and phenobarbital or propofol.

Cushing's Triad

Late physiological response to life-threatening elevation in intracranial pressure (ICP), characterized by severe hypertension with a widened pulse pressure, bradycardia, and irregular respirations (bradypnea).

Epidural Hematoma

Intracranial bleed typically caused by temporal bone (pterion) fracture tearing the middle meningeal artery; classically characterized by a loss of consciousness, a temporary lucid interval, and rapid secondary neurologic decline.

Subdural Hematoma

Venous intracranial hemorrhage caused by tearing of bridging veins between the cortex and dural sinuses, most commonly observed in elderly or alcohol-dependent individuals days to weeks following minor head trauma.

Subarachnoid Hemorrhage (SAH)

Bleeding into the subarachnoid space most frequently caused by saccular (berry) aneurysm rupture, presenting as a sudden severe "worst headache of life" (thunderclap headache), nuchal rigidity, and xanthochromia on lumbar puncture.

Myasthenia Gravis

Autoimmune neuromuscular disorder caused by antibodies directed against post-synaptic acetylcholine (ACh) receptors, presenting with descending fatiguable ptosis, diplopia, and skeletal muscle weakness that improves with rest.

Lhermitte Sign

Transient, electric-shock-like sensation radiating down the spine into the limbs upon neck flexion, characteristic of spinal cord demyelinating lesions in Multiple Sclerosis.

Brown-Séquard Syndrome

Incomplete spinal cord lesion resulting from hemisection of the cord, causing ipsilateral loss of motor function and proprioception/vibration paired with contralateral loss of pain and temperature sensation below the lesion level.

Cauda Equina Syndrome

Surgical emergency caused by compression of the lumbosacral nerve roots, presenting with saddle anesthesia, bilateral leg weakness, and loss of bowel or bladder sphincter tone.

Guillain-Barré Syndrome

Acute inflammatory post-infectious demyelinating polyneuropathy characterized by progressive, symmetric ascending muscle weakness and hyporeflexia, often requiring monitoring for respiratory failure.

S3 Heart Sound

Low-pitched diastolic sound occurring during early ventricular filling ("Ken-tuck-y"), indicating ventricular volume overload commonly found in systolic heart failure.

S4 Heart Sound

Low-frequency end-diastolic sound heard immediately before S1 ("Ten-ne-ssee"), caused by atria contracting into a non-compliant or stiff ventricle (e.g., from chronic hypertension or myocardial infarction).

HFrEF (Heart Failure with Reduced Ejection Fraction)

Systolic heart failure defined by a left ventricular ejection fraction $\text{EF} < 40\%$, presence of an S3 gallop, and management with guideline-directed medical therapy (beta-blocker, ACEI/ARNI, MRA, and SGLT2 inhibitor).

HFpEF (Heart Failure with Preserved Ejection Fraction)

Diastolic heart failure defined by a left ventricular ejection fraction $\text{EF} \ge 50\%$ accompanied by concentric remodeling, impaired relaxation, stiff ventricle (S4 gallop), managed primarily with diuretics and SGLT2 inhibitors.

Peripheral Vascular Disease (PVD)

Arterial atherosclerosis causing lower extremity ischemia, exertional claudication relieved by rest, diminished peripheral pulses, cool pale hairless skin, rubor on dependency, and dry toe ulcers with an $\text{ABI} < 0.9$.

Chronic Venous Insufficiency (CVI)

Venous incompetence with chronic blood pooling, characterized by lower extremity edema, aching worsening at day's end, warm thickened hyperpigmented (brown) skin, and wet ulcers localized over the medial ankle.

Prinzmetal (Variant) Angina

Episodic myocardial ischemia caused by coronary artery vasospasm in the absence of fixed occlusive plaque, typically occurring at rest overnight or early morning with transient ST-segment elevations.

Aortic Stenosis

Harsh crescendo-decrescendo systolic murmur radiating to the carotids, characterized by the classic "SAD" clinical triad of syncope, angina, and dyspnea (with dyspnea usually appearing first).

Cardiac Tamponade

Pericardial fluid accumulation causing hemodynamic collapse, characterized by Beck's Triad (hypotension, jugular venous distention, muffled heart sounds) and pulsus paradoxus, confirmed by echocardiography and treated via pericardiocentesis.

Undersensing (Pacemaker)

Pacemaker malfunction where the device fails to detect intrinsic cardiac depolarizations, leading to asynchronous pacing spikes delivered inappropriately early.

Failure to Capture (Pacemaker)

Pacemaker pacing issue where the generator discharges an electrical pacing spike, but the myocardium fails to depolarize, manifesting as a spike without a subsequent P wave or QRS complex.

Left Ventricular Assist Device (LVAD)

Continuous-flow mechanical circulatory pump implanted to bypass the left ventricle in end-stage heart failure, characterized by the absence of a standard palpable peripheral pulse and requiring blood pressure assessment by Doppler MAP.

Pulsus Paradoxus

Exaggerated decrease in systolic blood pressure of greater than $10\,\text{mmHg}$ during inspiration, classically found in cardiac tamponade and severe acute asthma exacerbations.

Acute Respiratory Distress Syndrome (ARDS)

Acute non-cardiogenic pulmonary edema from diffuse alveolar-capillary injury, diagnosed by bilateral radiographic infiltrates, normal left atrial pressure ($\text{PAOP} \le 18\,\text{mmHg}$, normal wedge), and $\text{PaO}_2/\text{FiO}_2 \le 300\,\text{mmHg}$ on PEEP $\ge 5\,\text{cm H}_2\text{O}$.

CURB-65

Pneumonia mortality prediction score evaluating Confusion, Uremia ($\text{BUN} > 19\,\text{mg/dL}$), Respiratory rate ($\ge 30\,\text{breaths/min}$), Blood pressure ($\text{SBP} < 90\,\text{mmHg}$ or $\text{DBP} \le 60\,\text{mmHg}$), and Age $\ge 65$.

Pulmonary Hypertension

Elevation of hemodynamic pressures defined by a resting mean pulmonary arterial pressure ($\text{mPAP}$) $> 20\,\text{mmHg}$ confirmed via right heart catheterization.

Fat Embolism Syndrome

Systemic condition occurring typically after long-bone fractures, presenting with a classic triad of acute hypoxemia, altered mental status, and a petechial rash over the chest and conjunctiva.

Diabetic Ketoacidosis (DKA)

Acute metabolic complication of diabetes marked by hyperglycemia ($\text{BG} > 250\,\text{mg/dL}$), anion gap metabolic acidosis ($\text{pH} < 7.3$, $\text{bicarbonate} < 18\,\text{mEq/L}$), ketonemia, and Kussmaul respirations.

Hyperosmolar Hyperglycemic State (HHS)

Severe hyperglycemic emergency most common in older adults with type 2 diabetes, marked by severe glucose elevation ($> 600\,\text{mg/dL}$), hyperosmolality ($> 320\,\text{mOsm/kg}$), profound dehydration, and minimal or absent ketoacidosis ($\text{pH} > 7.3$).

Thyroid Storm

Acute, life-threatening decompensated state of hyperthyroidism presenting with hyperthermia, tachyarrhythmias, and delirium, treated with beta-blockers, thionamides (PTU/methimazole), iodine, and corticosteroids (avoiding aspirin).

Addison's Disease

Primary adrenal insufficiency caused by destruction of the adrenal cortex, leading to deficiencies of cortisol and aldosterone, cutaneous hyperpigmentation, hypotension, hyponatremia, and hyperkalemia.

Pheochromocytoma

Catecholamine-producing neuroendocrine tumor of the adrenal medulla causing episodic paroxysmal hypertension, palpitations, headache, and diaphoresis, requiring non-selective alpha-blockade before initiating beta-blocker therapy.

Diabetes Insipidus (DI)

Water balance disorder caused by insufficient ADH release (central) or renal resistance (nephrogenic), manifesting as polyuria ($> 200\,\text{mL/hr}$), dilute urine ($\text{urine osmolality} < 100\,\text{mOsm/kg}$), hypernatremia, and elevated serum osmolality ($> 295\,\text{mOsm/kg}$).

SIADH

Syndrome of Inappropriate Antidiuretic Hormone secretion causing non-physiologic water reabsorption, leading to dilutional euvolemic hyponatremia ($< 130\,\text{mEq/L}$), decreased serum osmolality ($< 280\,\text{mOsm/kg}$), and inappropriately concentrated urine ($> 100\,\text{mOsm/kg}$).

Disseminated Intravascular Coagulation (DIC)

Systemic thrombohemorrhagic disorder characterized by widespread microvascular fibrin deposition, consumption of platelets and clotting factors, elevated D-dimer, decreased fibrinogen, and diffuse hemorrhage.

Heparin-Induced Thrombocytopenia (HIT)

Immune-mediated adverse drug reaction caused by IgG antibodies directed against platelet factor 4 (PF4)-heparin complexes, producing a platelet count drop of $> 50\%$ accompanied by high paradoxical thrombosis risk.

Multiple Myeloma

Clonal plasma cell malignancy defined by the CRAB criteria (hyperCalcemia, Renal insufficiency, Anemia, Bone lytic lesions) and the presence of Bence-Jones proteins or monoclonal spikes.

Tumor Lysis Syndrome (TLS)

Oncologic emergency following initiation of cytotoxic therapy for hematologic malignancies, characterized by rapid cell breakdown resulting in hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia.

Compartment Syndrome

Increased intracompartmental pressure within an inelastic fascial envelope ($> 30\,\text{mmHg}$ or a delta perfusion pressure $< 30\,\text{mmHg}$), causing ischemic muscle pain out of proportion to exam and requiring emergent decompressive fasciotomy.

Parkland Formula

Fluid resuscitation protocol for severe thermal burns calculating 24-hour crystalloid requirements as $4\,\text{mL} \times \text{weight (kg)} \times \%\text{TBSA}$ burned (second- and third-degree), infusing the first half over the first $8\,\text{hours}$ post-injury.

Neurogenic Shock

Distributive shock caused by cervical or high thoracic spinal cord injury, characterized by loss of sympathetic vasomotor and cardiac tone resulting in simultaneous hypotension and bradycardia.

Rhabdomyolysis

Skeletal muscle breakdown releasing myoglobin, electrolytes, and enzymes into circulation, confirmed by creatine kinase ($\text{CK}$) $> 5\times$ normal or $> 10{,}000\,\text{U/L}$, presenting with tea-colored urine and acute tubular necrosis risk.

Hepatorenal Syndrome (HRS)

Reversible functional renal vasoconstriction occurring in severe liver cirrhosis and portal hypertension due to marked splanchnic arterial vasodilation, managed with volume expansion via albumin, midodrine, and octreotide.

Light's Criteria

Diagnostic criteria differentiating exudative from transudative pleural effusions; an effusion is exudative if pleural/serum protein ratio is $> 0.5$, pleural/serum LDH ratio is $> 0.6$, or pleural LDH is $> 2/3$ the upper limit of normal serum LDH.

Stevens-Johnson Syndrome (SJS)

Severe, immune-mediated mucocutaneous reaction commonly triggered by medications (e.g., anticonvulsants, sulfonamides, allopurinol), causing blistering, mucosal erosion, and epidermal detachment affecting $< 10\%$ of total body surface area.

Duty to Warn (Tarasoff Rule)

Legal and ethical mandate requiring healthcare providers to breach confidentiality to notify identifiable third parties and law enforcement when a patient verbalizes an explicit, serious threat of bodily harm.