Nursing Fundamentals: Toxic Drug Levels, Lab Values, Vital Signs, and Electrolytes

Vocabulary practice flashcards generated from nursing lecture documents covering drug toxicity levels, laboratory normal ranges, vital signs, and fluid & electrolyte imbalances.

Lithium Toxicity Level & Signs

Toxicity occurs at $1.5+$; top signs include extreme thirst, excessive urination, and vomiting or diarrhea.

Digoxin Toxicity Level & Signs

Toxicity occurs at $2.0+$; top signs include nausea, vomiting, and vision changes described as "difficulty reading".

Theophylline Toxicity Level & Signs

Toxicity occurs at $20+$; top sign is tonic-clonic seizures.

Phenytoin Toxicity Level & Signs

Toxicity occurs at $20+$ (brand name Dilantin); top signs are ataxia (unsteady gait), hand tremors, and slurred speech.

Kidney Killers (Creatinine Threshold & Nephrotoxic Agents)

Creatinine levels over $1.3$ indicate severe renal impairment ("bad kidney"); major risk factors and agents include renal failure, older age, CT contrast, and "-mycin" antibiotics like Vancomycin and Gentamicin.

Normal Laboratory Range: Serum Sodium ($Na^+$)

$135 - 145\,mEq/L$; primarily functions to maintain blood pressure, blood volume, pH balance, and swells the body with fluid.

Normal Laboratory Range: Serum Potassium ($K^+$)

$3.5 - 5.0\,mEq/L$; plays a priority role in heart pumping and muscle function.

Normal Laboratory Range: Serum Calcium ($Ca$)

$9.0 - 10.5\,mg/dL$; contracts muscles and maintains the 3 Bs: Bone strength, Blood clotting, and Heartbeats.

Normal Laboratory Range: Serum Magnesium ($Mg^+$)

$1.3 - 2.1\,mEq/L$; functions primarily to mellow the muscles.

Normal Laboratory Range: Blood Urea Nitrogen (BUN)

$10 - 20\,mg/dL$; standard lab parameter used to evaluate renal function.

Normal Laboratory Range: Serum Fasting Glucose

$70 - 110\,mg/dL$; critical brain energy source where hypoglycemia can cause brain cell death.

Normal Laboratory Range: White Blood Cells (WBC)

$5,000 - 10,000/\mu L$; low values indicate risk for infection while high values indicate active infection.

Normal Laboratory Range: Hemoglobin (Hgb)

Males: $14 - 18\,g/dL$, Females: $12 - 16\,g/dL$; levels below $7\,g/dL$ require a blood transfusion.

Normal Laboratory Range: Platelets (PLTS)

$150,000 - 400,000/\mu L$; low values indicate anemia/bleeding risk, targeted by antiplatelet drugs like aspirin and clopidogrel.

Therapeutic Anticoagulation Ranges: aPTT and INR

Normal aPTT is $30 - 40\,\text{seconds}$ (therapeutic range on anticoagulants is $46 - 70\,\text{seconds}$); normal INR is $0.9 - 1.2$ (therapeutic range on anticoagulants is $2 - 3$).

Vital Sign Normals: Pulse Rate

$60 - 100\,\text{BPM}$; evaluated at radial, carotid, brachial, femoral, popliteal, dorsalis pedis, or posterior tibialis sites.

Vital Sign Normals: Respirations

$12 - 20\,\text{BPM}$; evaluated at anterior (chest) and posterior (back) locations.

Vital Sign Normals: Blood Pressure (BP)

Below $120\,\text{mmHg}$ systolic and below $80\,\text{mmHg}$ diastolic; systole represents maximum contraction of the left ventricle, and diastole represents resting pressure of the ventricles.

Hypoxia Classifications by $O_2$ Saturation

Normal: $95 - 100\%$, Mild hypoxia: $91 - 94\%$, Moderate hypoxia: $86 - 90\%$, Severe hypoxia: $<85\%$.

Crackles (Breath Sounds)

Adventitious breath sounds described as sounding like salt dropped onto a hot pan, cellophane being crumpled, or velcro being torn open.

Rhonchi (Breath Sounds)

Continuous low-pitched, rattling lung sounds that often resemble snoring.

Wheezes (Breath Sounds)

Continuous, coarse, whistling sounds produced in the airways when the respiratory tree is narrowed or obstructed, or when airflow velocity is heightened.

Diminished or Absent Breath Sounds

Decreased or absent lung sounds caused by air or fluid in or around the lungs, seen in pneumonia, heart failure, and pleural effusion.

Vital Sign Normals: Body Temperature

$98.6^\circ\text{F} / 37^\circ\text{C}$; assessed at temporal, rectal, oral, or axillary locations, classified as febrile or afebrile.

Hyperkalemia

Serum potassium over $5.0\,mEq/L$; features high heart pumps (peaked T waves, ST elevation, V-fib, cardiac arrest, hypotension, bradycardia), high neuromuscular signs (increased DTR, paresthesia, heaviness/weakness), and high GI output (diarrhea, hyperactive bowel sounds).

Hypokalemia

Serum potassium below $3.0\,mEq/L$; features low/slow heart pumps (flat T waves, ST depression, U wave), low/slow neuromuscular signs (shallow respirations - most deadly, decreased DTR, flaccid paralysis), and low/slow GI (constipation, hypoactive bowel sounds, paralytic ileus).

Hypernatremia

Serum sodium over $145\,mEq/L$; presents as "Big & Bloated" body manifestations (edema, flushed skin, increased muscle tone, swollen dry tongue, nausea/vomiting) often caused by Diabetes Insipidus ("Dry Inside").

Hyponatremia

Serum sodium below $135\,mEq/L$; presents as "Low & Slow" brain manifestations (headache from cerebral edema, mental status changes, seizures, coma) and respiratory arrest.

Hypermagnesemia

Serum magnesium over $2.1\,mEq/L$; presents as "High Mellow" manifestations (heart block, hypotension, bradycardia, depressed respirations, hypoactive bowel sounds, decreased DTR).

Hypomagnesemia

Serum magnesium below $1.3\,mEq/L$; presents as "Low Mellow - Excited!" manifestations (Torsades de Pointes, ventricular fibrillation, increased DTR/hyperreflexia, diarrhea, hyperactive bowel sounds).

Hypercalcemia

Serum calcium over $10.5\,mg/dL$; presents as "HIGH Calm" manifestations (kidney stones/renal calculi, constipation, bone pain, severe muscle weakness/lethargy) caused by hyperparathyroidism, cancer, or immobility.

Hypocalcemia

Serum calcium below $9.0\,mg/dL$; presents as "Low Calm = Excited!" signs including Trousseau's sign (arm twerking with BP cuff/tetany), Chvostek's sign (cheeky smile when stroking face), diarrhea, and weak bones/blood/beats.

Calcium and Phosphate Inverse Relationship

When serum calcium is high, phosphate is low, and vice versa; hyperphosphatemia ($>4.5\,mg/dL$) presents with low calcium signs, while hypophosphatemia ($<3.0\,mg/dL$) presents with high calcium signs.