Fluid and Electrolyte Imbalances Lecture Review

FLUID AND ELECTROLYTE IMBALANCES: HOMEOSTASIS AND REGULATION

PAGE 1

Introduction to Electrolytes

Key Ions: * Sodium ( $Na^+$ ) * Potassium ( $K^+$ ) * Calcium ( $Ca^{++}$ ) * Magnesium ( $Mg^{++}$ )
Central Themes: Fluid and electrolyte imbalances, homeostasis, and physiological regulation.

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Clinical Reference: Lab Values

Serum Electrolytes: * Sodium ( $Na^+$ ): $136\text{ TO }145\,mEq/L$ * Potassium ( $K^+$ ): $3.5\text{ TO }5\,mEq/L$ * Calcium Total ( $Ca^{++}$ ): $9.0\text{ TO }10.5\,mg/dL$ * Magnesium ( $Mg^{++}$ ): $1.3\text{ TO }2.1\,mEq/L$ * Phosphorus ( $PO_4$ ): $3.0\text{ TO }4.5\,mg/dL$ * Chloride ( $Cl$ ): $98\text{ TO }106\,mEq/L$
Ancillary Renal and Fluid Labs: * Specific Gravity: $1.005-1.030$ * Creatinine: * Male: $0.6-1.2$ * Female: $0.5-1.1$ * BUN (Blood Urea Nitrogen): $10-20$

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Theoretical Framework: Fluid & Electrolytes

Core Concept Definition: According to Giddens (2025), "The concept fluid and electrolytes refers to the process of regulating the extracellular fluid volume, body fluid osmolality, and plasma concentrations of electrolytes."
Fundamental Principle: All body fluids contain electrolytes. Fluids in different anatomical locations normally contain different concentrations of these electrolytes, which are necessary for optimal physiological function.

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The Fluid and Electrolyte (F&E) Continuum

To maintain homeostasis, the body systemically attempts to keep fluid volume (FV), osmolality, and electrolyte concentrations at optimal levels. The continuum of balance is as follows:

Extracellular Fluid Volume (ECV): * Deficit: $ECV\text{ Deficit}$ * Balance: $\text{Optimal }ECV$ * Excess: $ECV\text{ Excess}$
Osmolality (Sodium as Proxy): * Too Dilute: Na^+ < 135\,mEq/L; \text{Osm} < 280\,mosmol/kg * Optimal: $Na^+ = 135-145\,mEq/L$ ; $\text{Osm } 280-300\,mosmol/kg$ * Too Concentrated: Na^+ > 145\,mEq/L; \text{Osm} > 300\,mosmol/kg
Potassium Concentration: * Hypokalemia: K^+ < 3.5\,mEq/L * Optimal: $K^+ = 3.5-5.0\,mEq/L$ * Hyperkalemia: K^+ > 5.0\,mEq/L

PAGE 5

Categories of Fluid Imbalances

Volume Disturbances: These refer to disturbances in the amount (volume) of fluid specifically within the extracellular compartment.
Osmolality Disturbances: These refer to disturbances in the concentration of body fluids, also clinically identified as Sodium ( $Na^+$ ) Imbalances.

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Clinical Case Study: Maria Santos (I)

Patient Profile: 68-year-old female.
Presentation: Arrives at the Emergency Department (ED) accompanied by her daughter.
History: Severity of vomiting and diarrhea for $3\text{ days}$ following a suspected viral gastroenteritis.
Initial Appearance: Weak and confused.
Assessment Findings (Vital Signs): * Blood Pressure (BP): $92/58\,mmHg$ (Baseline: $128/76\,mmHg$ ) * Heart Rate (HR): $118\,bpm$ (Quality: Thready) * Respiratory Rate (RR): $22/min$ * Temperature: $99.8^{\circ}F$ ( $37.7^{\circ}C$ ) * Orthostatic Changes: BP drops to $78/50\,mmHg$ upon standing; HR increases to $132\,bpm$ . Patient reports severe dizziness.

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Clinical Case Study: Maria Santos (II) - Physical Assessment

Integumentary/Mucosa: Dry mucous membranes, decreased skin turgor (demonstrated by skin tenting on the forearm).
Ocular: Sunken eyes, absence of tears when crying.
Circulatory: Capillary refill time of $4\text{ seconds}$ .
Weight: Loss of $5\,kg$ from her last clinic visit $1\,week$ ago.
Urological: Dark amber, highly concentrated urine.
24-Hour Intake & Output (I&O): * Intake: $400\,mL$ oral fluids. * Output: $150\,mL$ urine (dark, concentrated); 6 episodes of watery diarrhea; 4 episodes of vomiting.

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Clinical Case Study: Maria Santos (III) - Laboratory Data

Hematocrit: $52\%$
BUN: $38\,mg/dL$
Creatinine: $1.8\,mg/dL$
Sodium: $152\,mEq/L$
Potassium: $3.2\,mEq/L$
Urine Specific Gravity: $1.035$
Current Status: Patient reports feeling "very weak" and "extremely thirsty." She has significant difficulty standing without physical assistance.

PAGE 9

Think About It: Maria Santos Analysis

What assessment data would be clustered together?
What is the relationship between Maria's weight loss and fluid imbalance? (Note: $1\,kg$ of weight is equivalent to approximately $1\,L$ of fluid).
Why are her BUN, Creatinine, and Hematocrit values elevated? (Note: Hemoconcentration).
What interventions should be prioritized for Maria's care?
What type of IV fluid replacement would be most appropriate and why?
What are the two most important parameters to monitor during the rehydration process?

PAGE 10

Fluid Volume Deficit (FVD) / Dehydration

Pathophysiology: Characterized by decreased fluid intake or decreased fluid retention. It is an actual decrease in total body water due to insufficient intake or excessive loss.
Isotonic Loss: Water and sodium are lost in proportional amounts.
Vascular Dehydration: Refers to a relative loss occurring when fluid shifts from the plasma into the interstitial space.
Hypovolemia: A decrease in the circulating blood volume within the vascular space, leading to an increased concentration of plasma.

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Hypovolemia (SLO 1, 2, 3, 5)

Etymology: Low (hypo) + Blood (vol) + Volume (emia).
Definition: Low volume in the Extracellular Fluid (ECF) resulting from the loss of both body fluids and electrolytes. This is distinct from simple dehydration.
Clinical Goal: Treat the underlying cause and replace lost volume.
Etiology: Any condition where fluids or blood are lost from the intravascular volume, including: * Bleeding/Hemorrhage * Vomiting and Diarrhea * Third Spacing
Consequences: Impaired perfusion to vital organs. If untreated, the client will progress into hypovolemic shock.

PAGE 12

Third Spacing

Definition: Fluid shifts from the vascular space into non-functional areas.
Locations of Sequestration: * Abdomen or bowel * Pleural space (lungs) or peritoneal space * Interstitial tissues
Implications: Trapped fluid constitutes a volume loss to the functional system. This fluid is unavailable to support normal physiological processes.
Assessment Challenges: Difficult to assess clinically; may not be reflected in standard measurable data like I&O.

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Nursing Solutions and Actions for Fluid Deficit

Primary Goals: Prevent further loss, restore fluid volume to normal, and prevent injury.
Fluid Replacement Strategies: * Oral: Replace small amounts every $2\text{ hours}$ . * IV Crystalloids: Most common replacement fluid. * IV Colloids: Contain larger non-water-soluble molecules that increase osmotic pressure in the plasma volume.
Monitoring Effectiveness: Targeted monitoring of urine output, pulse rate, and pulse quality.
Drug Therapy: Directed at underlying causes (e.g., antidiarrheals, antimicrobials, antiemetics, antipyretics).
Injury Prevention: * Regular monitoring of vital signs. * Fall prevention protocols: Hourly rounding (can be delegated). * Assessment of alertness/level of consciousness (LOC). * Assessment of muscle strength and gait.

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Lifespan Clinical Manifestations (SLO 1, 2, 4)

Children

Irritability (infants), thirst (older children).
Lethargy and sleepiness.
Decreased skin turgor and dry mucous membranes.
Tachycardia (increased pulse) and tachypnea (increased respirations).
Decreased blood pressure (BP).
Seizure activity.
Decreased or absent urine output.
Variable body temperature.
Significant weight loss.
Increased urine specific gravity.

Older Adults

Altered mental status, memory, and attention.
Skin turgor is less reliable as an indicator due to loss of elasticity.
Dry mucous membranes and the presence of tongue furrows.
Itchy skin and brittle hair.
Loss of the thirst reflex.

PAGE 15

Evaluation and Expected Outcomes

Scenario: A nurse is caring for a client with dehydration. Which assessment finding indicates improvement in hydration status?

Equal handgrip strength
Negative Trousseau sign
Correct Indicator: Urine output of $100\,mL$ in the last 7 hours (Improved compared to severe oliguria)
Neck vein distention in the supine position (Though supine distention is normal, it can also indicate excess if too prominent).

PAGE 16

Case Application: Older Adult

Patient: 78-year-old admitted for vomiting and diarrhea for $2\text{ days}$ . Home meds include a diuretic.
Findings: * Temp: $38.3^{\circ}C$ ( $100.9^{\circ}F$ ); Pulse: $127\,bpm$ ; BP: $100/57\,mmHg$ ; RR: $24/min$ ; ${O}_2$ Sat: $92\%\text{ on Room Air}$ . * Cardiac: Sinus tachycardia. * Lungs: Clear, regular respirations, non-labored at rest. * Output: Indwelling catheter with $110\,mL$ amber, concentrated urine in the last $5\text{ hours}$ . * Physical: Tenting of the skin over the sternum. Deep furrows on the tongue. Dry mucous membranes and crusty, dry lips. * Cognitive: Responds to questions and acknowledges not feeling well.

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Clinical Case Study: Maria Santos (Heart Failure Context) (I)

Patient Profile: 68-year-old female with a history of Chronic Heart Failure.
Presentation: Reports increasing shortness of breath, leg swelling, and orthopnea (difficulty sleeping flat in bed) for the past $5\text{ days}$ .
History: Admitted to eating canned soups and processed foods; admitted to "forgetting" her diuretic medication.
Assessment Findings (Vital Signs): * BP: $168/94\,mmHg$ (Baseline: $128/76\,mmHg$ ) * HR: $96\,bpm$ (Quality: Bounding) * RR: $26/min$ * Temp: $98.2^{\circ}F$ ( $36.8^{\circ}C$ ) * ${O}_2$ Sat: $89\%\text{ on Room Air}$

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Clinical Case Study: Maria Santos (HF) (II) - Physical Assessment

Neck Veins: Jugular Venous Distention (JVD) visible at a $45\text{-degree}$ angle.
Respiratory: Crackles in bilateral lung bases.
Circulatory: Strong, bounding peripheral pulses.
Musculoskeletal: $3+$ pitting edema in bilateral lower extremities extending to the mid-calf.
Abdominal: Ascites present with abdominal distention.
Cardiac: $S_3$ heart sound auscultated.
Weight: Gain of $7\,kg$ from last clinic visit $1\,week$ ago.
24-Hour I&O: * Intake: $2800\,mL$ * Output: $600\,mL$ urine (pale yellow)

PAGE 19

Clinical Case Study: Maria Santos (HF) (III) - Laboratory Data

Hematocrit: $36\%$
BUN: $28\,mg/dL$
Creatinine: $1.4\,mg/dL$
Sodium: $132\,mEq/L$
Potassium: $3.4\,mEq/L$
Urine Specific Gravity: $1.010$
Current Status: Patient states, "I can't catch my breath," and requires $3\text{ pillows}$ to sleep. Reports rings are tight and shoes do not fit.

PAGE 20

Think About It: Fluid Excess Analysis

What assessment findings indicate fluid imbalance?
How does the $7\,kg$ weight gain relate to fluid retention?
Why is her sodium decreased despite having fluid overload? (Note: Dilutional hyponatremia).
What is the significance of JVD and bounding pulses?
What priority interventions would you implement?
What patient teaching is essential for discharge?

PAGE 21

Fluid Volume Excess (FVE) (SLO 1, 2)

Definitions: Also known as overhydration or hypervolemia. Excess body fluid occurs when intake is greater than the body's needs or retention is greater than needs.
Hypervolemia: Specifically refers to excess in the Extracellular Fluid (ECF) space/vascular space; leads to dilution of specific electrolytes and blood components.
Primary Causes: 1. Excessive intake. 2. Inadequacy of secretion/excretion mechanism.

PAGE 22

Risk Factors and Causes for FVE (SLO 1)

Treatment-Related: Excessive IV infusion of $Na^+$ containing isotonic fluids (e.g., $0.9\%\,NS$ or Lactated Ringer’s [ $LR$ ]).
Dietary: High intake of salty foods and water.
Renal: Retention of sodium and water due to oliguria (as in Acute Kidney Injury [AKI] or End-Stage Renal Disease [ESRD]).
Organ Failure: Heart failure and liver failure.
Medications/Hormones: Long-term corticosteroid therapy or Syndrome of Inappropriate Antidiuretic Hormone (SIADH).
Psychological: Psychiatric disorders with polydipsia; water intoxication.

PAGE 23

Pediatric Assessment Findings: Fluid Excess

Edema: Generalised or pulmonary (characterized by moist rales/crackles).
Pulse: Slow but bounding.
Weight: Gain.
Neurological: Lethargy.
Laboratories: Low urine specific gravity, decreased serum electrolytes, and decreased hematocrit.

PAGE 24

Taking Action: Fluid Overload (SLO 5)

Priority 1: Safety: Frequent respiratory assessment following the ABC (Airway, Breathing, Circulation) priority framework.
Skin Integrity: Assessing edema and providing pressure-reducing or pressure-relieving surfaces (can be delegated).
Drug Therapy: Removal of excess fluid using diuretics. The nurse must monitor relevant labs (e.g., potassium).
Nutrition: Implement fluid restrictions or sodium limitations.
Monitoring I/O: Every shift (can be delegated).
Daily Weights: Must be standardized (same scale, same time, same clothing) (can be delegated).

PAGE 25

Critical Thinking Question

Scenario: Which client is at risk for Fluid Volume Excess (FVE)?

Correct Answer: B. The client with kidney disease (due to inability to excrete fluids).
Incorrect Options: A (Diuretics risk FVD), C (Ileostomies lose fluid), D (GI suctioning loses fluid).

PAGE 26

Clinical Case Study: James Chen

Patient Profile: 72-year-old male.
Presentation: Found confused at home.
History: Taking Hydrochlorothiazide (a thiazide diuretic) for Hypertension for $6\text{ months}$ .
Assessment Findings (Vital Signs): * BP: $98/62\,mmHg$ * HR: $108\,bpm$ (Quality: Weak, thready) * RR: $18/min$
Neurological: Acute confusion, lethargic, difficulty focusing.
Neuromuscular: Generalized muscle weakness in arms and legs; diminished deep tendon reflexes (DTRs).
GI: Hyperactive bowel sounds, nausea, abdominal cramping, watery diarrhea.
Cardiovascular: Peripheral pulses weak and easily blocked; orthostatic hypotension present.

PAGE 27

Case Study: James Chen Labs

Sodium ( $Na^+$ ): $128\,mEq/L$
Potassium ( $K^+$ ): $3.3\,mEq/L$
Chloride ( $Cl$ ): $92\,mEq/L$
Osmolality: $265\,mosm/kg$

PAGE 28

Sodium ( $Na^+$ ) and Osmolality Imbalances

Mechanisms of Imbalance: 1. Water imbalance (Hypovolemia or Hypervolemia). 2. Actual Sodium imbalance.
Standard Level: $136-145\,mEq/L$ .
Regulation: Primarily by the kidneys. * Antidiuretic Hormone (ADH): Influences kidneys to excrete or retain water to regulate sodium concentration in ECF. * Aldosterone: Promotes sodium reabsorption from renal tubules.
Sodium Loss Routes: Urine, feces, and sweat.

PAGE 29

SIADH (Syndrome of Inappropriate Antidiuretic Hormone)

Mnemonic: "Seriously Increased ADH".
Pathophysiology: ADH is released even when plasma osmolality is normal or low (normally it only releases when high).
Outcome: ADH causes the kidneys to hold onto water, increasing ECF.
Clinical Signs: * Serum hypo-osmolality and dilutional hyponatremia. * Weight gain without edema. * Concentrated urine with low output and high specific gravity. * Mild Signs: Muscle cramping, pain, weakness. * Severe Signs (Sodium < $115\,mEq/L$ ): Vomiting, abdominal cramps, muscle twitching, and seizures.

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Treatment of Hyponatremia

If Water Excess: Restrict fluids.
Nutritional: Increase oral sodium via food.
If Fluid Deficit: Administer IV saline infusion.
Severe Symptomatology (Seizures): Hypertonic saline ( $3\%\text{ or }5\%\,NS$ ) with extremely close monitoring.
Seizure Risk: High when Sodium is below $120\,mEq/L$ .
Pharmacology: Conivaptan and Tolvaptan (ADH blockers).

PAGE 31

Clinical Case Study: Susan Martinez

Patient Profile: 78-year-old female with dementia.
Assessment Findings (Vital Signs): * BP: $156/88\,mmHg$ * HR: $88\,bpm$ (Quality: Bounding) * RR: $20/min$ * Temp: $100.2^{\circ}F$
Neurological: Agitated, short attention span, restless.
Neuromuscular: Muscle twitching in arms, irregular muscle contractions; initially hyperactive reflexes.
Skin: Dry mucous membranes, poor skin turgor, flushed skin.
Cardiovascular: Full, bounding peripheral pulses that are difficult to block.

PAGE 32

Case Study: Susan Martinez Labs

Sodium ( $Na^+$ ): $158\,mEq/L$
Potassium ( $K^+$ ): $4.2\,mEq/L$
Chloride ( $Cl$ ): $118\,mEq/L$
Osmolality: $320\,mosm/kg$
BUN: $32\,mg/dL$

PAGE 33

Hypernatremia (Na^+ > 145\,mEq/L)

Definition: High sodium concentration or insufficient water in the ECF.
Osmolality: Serum osmolality increases (> 300\,mosm/kg; transcript shows < 290 as a comparison point but clinically is high).
Cellular Effect: Causes cellular dehydration as water shifts out of the cells to balance the high solute concentration in the ECF (cells shrink).
Natural Defense: Thirst mechanism and the release of ADH.

PAGE 34

Common Causes of Hypernatremia

Actual Sodium Excess: * Hyperaldosteronism * Kidney Failure * Corticosteroids * Cushing Syndrome/Disease * Excessive oral or IV sodium intake
Relative Sodium Excess (Water Loss/Dehydration): * Increased metabolic rate or Fever * Hyperventilation * Infection * Excessive diaphoresis * Watery diarrhea

PAGE 35

Treatment of Hypernatremia

Treat the underlying cause.
If Water Deficit: Replace fluids with isotonic ( $0.9\%\,NS$ ) or hypotonic solutions ( $D5W\text{ or }D5\text{ in }0.45\%\,NS$ ).
If Sodium Excess: Dilute sodium with $D5W$ and administer diuretics.
Dietary: Restrict dietary sodium.
Safety Warning: Do not replace fluids too rapidly, as this can cause the opposite problem (cerebral edema).

PAGE 36

Focus on Lifespan: Sodium Imbalance

Infants and Elderly: At highest risk for FVD and hypernatremia because of decreased ability to respond to thirst or express thirst.
Mechanisms: Water loss via diarrhea, vomiting, fever, and inadequate intake.
Physiological factors in Elderly: Impaired thirst response and decreased glomerular filtration rate (GFR).
Infants: Prevention requires ensuring baby formula is mixed correctly. Breastfed babies are also at risk if maternal intake is poor.
Ethical/Legal Note: Water deprivation in children is categorized as child abuse.

PAGE 37

Think About It: Sodium Comparison

Compare the neuromuscular findings: James (Hyponatremia) has weakness and diminished DTRs; Susan (Hypernatremia) has twitching and initially hyperactive reflexes.
Pulse differences: James has weak pulses (likely also hypovolemic); Susan has bounding pulses (likely hypervolemic/concentrated).
What are the priority interventions for each?
How would treatment differ?

PAGE 38

Clinical Case Study: David Thompson

Patient Profile: 58-year-old male.
Assessment Findings (Vital Signs): * BP: $138/82\,mmHg$ * HR: $52\,bpm$ (Quality: Irregular) * RR: $16/min$ * Temp: $98.6^{\circ}F$
Neuromuscular: Profound weakness in quadriceps (bilateral); difficulty rising from a chair; diminished DTRs.
Neurological: Reports paresthesia (tingling) in hands and feet; nocturnal leg cramps.
GI: Hypoactive bowel sounds, abdominal distention, no bowel movement in $4\text{ days}$ , nausea, and anorexia.
Cardiovascular (ECG): Flattened T-waves, depressed ST segments, and prominent U-waves.

PAGE 39

Case Study: David Thompson Labs

Potassium ( $K^+$ ): $2.3\,mEq/L$
Sodium ( $Na^+$ ): $138\,mEq/L$
Chloride ( $Cl$ ): $96\,mEq/L$
Magnesium ( $Mg^{++}$ ): $1.4\,mg/dL$
Digoxin Level: $1.8\,ng/mL$ (Patient takes $0.125\,mg$ daily).
24-Hour I&O: Intake $2200\,mL$ ; Output $2800\,mL$ urine.
Current Status: Reports fatigue and anxiety over cardiac "skipping"; states he can barely walk.

PAGE 40

Think About It: Hypokalemia Analysis

What factors contributed to David's low potassium?
Why is the combination of hypokalemia and Digoxin therapy dangerous? (Note: Potassium and Digoxin compete for the same receptors; low K increases Digoxin binding/toxicity).
What are priority interventions?
Why monitor Magnesium? (Note: Low Mg makes it difficult to correct low K).
ECG Significance: flattened T, U-waves.

PAGE 41

Hypokalemia: Causes

Abnormal GI Loss: Vomiting, NG suctioning, diarrhea, laxative abuse, new ileostomy.
Renal Loss: Excessive diuretics (e.g., Lasix), corticosteroids, or secondary to low magnesium (elevated aldosterone).
Skin Loss: Diaphoresis, wound drainage.
Intracellular Shifts (ECF to ICF): Metabolic alkalosis; periods of tissue repair (burns, trauma, starvation); TPN; Insulin therapy (particularly in DKA treatment).
Intake: Deficient dietary potassium.

PAGE 42

Population at Risk: Hypokalemia

Older Adults: High risk due to diuretic and laxative use.
Special Risk – Digoxin: Hypokalemia potently increases the risk of Digoxin toxicity.
Special Risk – Insulin: Treatment for DKA drives potassium into the cells.

PAGE 43

Pharmacology: Digoxin Focus

Classification: Antiarrhythmic; High-alert drug.
Therapeutic Range: Very narrow.
Effects: Increases cardiac output, decreases HR.
Toxicity Signs: Abdominal pain, anorexia, N/V, visual disturbances, bradycardia, arrhythmias.
Electrolyte Relations: * Hypokalemia: Increases toxicity risk. * Hyperkalemia: Decreases Digoxin effectiveness. * Hypercalcemia: Increases toxicity risk. * Hypomagnesemia: Increases toxicity risk.

PAGE 44

Signs and Symptoms of Hypokalemia: SUCTION Mnemonic

S: Skeletal muscle weakness.
U: U-wave on EKG.
C: Constipation (slow GI motility).
T: Toxic effects of Digoxin.
I: Irregular, weak pulse.
O: Orthostatic Hypotension.
N: Numbness (paresthesias).

PAGE 45

Nursing Actions for Hypokalemia

Safety/Monitoring: Respirations (gas exchange), output, LOC, abdominal assessment, hand grip strength.
Replacement: Encourage potassium-rich foods; Oral supplements.
IV Replacement Protocol: * NEVER administer Potassium via IV Push. * NEVER give IM or SQ. * Always use an infusion pump.

PAGE 46

Drug Alert: Intravenous Potassium Administration

Dilution Requirement: Must be diluted and administered slowly.
Rate: Recommended infusion rate is $5\text{ TO }10\,mEq/hr$ .
Contraindication: National Client Safety Goals (NSPSGs) forbid IV push of potassium as it causes immediate cardiac arrest/death.

PAGE 47

Clinical Reasoning Question

Scenario: Which client should the nurse assess most frequently for signs of hypokalemia?

Correct Answer: 22-year-old receiving an IV infusion of Regular Insulin for ketoacidosis (Insulin causes a rapid shift of potassium into cells).

PAGE 48

Clinical Case Study: Robert Williams

Patient Profile: 65-year-old male with Stage 4 Chronic Kidney Disease (CKD).
Presentation: Brought to ED with weakness, confusion, and racing/skipping heart.
Meds: Lisinopril (ACE Inhibitor) and Spironolactone (Potassium-sparing diuretic).
Assessment Findings (Vital Signs): * BP: $142/88\,mmHg$ * HR: $48\,bpm$ (Quality: Irregular, Bradycardia) * RR: $18/min$
Neuromuscular: Profound weakness (lower extremities); flaccid muscle tone; difficulty moving legs; paresthesia of face, tongue, hands, and feet; ascending paralysis from legs upward.
GI: Hyperactive bowel sounds, nausea, intestinal cramping, diarrhea.

PAGE 49

Robert Williams Cardiac/ECG

Tall, peaked T-waves.
Prolonged PR interval.
Widened QRS complex.
Depressed ST segment.
Bradydysrhythmia.

PAGE 50

Case Study: Robert Williams Labs

Potassium ( $K^+$ ): $7.2\,mEq/L$
Sodium ( $Na^+$ ): $136\,mEq/L$
BUN: $68\,mg/dL$
Creatinine: $4.2\,mg/dL$
pH: $7.28$
Calcium ( $Ca^{++}$ ): $8.2\,mg/dL$
Current Status: Anxious; states "I can barely move my legs"; monitor is alarming.

PAGE 51

Think About It: Hyperkalemia Analysis

Factors: Stage 4 CKD (can't excrete), ACE inhibitor and K-sparing diuretic (retain K).
Why are ECG changes life-threatening? (Note: Risk of V-fib or standstill).
Metabolic acidosis: Worsens hyperkalemia as Hydrogen ions move into cells and kick Potassium out into the ECF.
Calcium Significance: Calcium gluconate protects the heart by antagonizing the cardiac effects of high K.
Medications that shift K intracellularly: Albuterol and Insulin/Glucose.

PAGE 52

Hyperkalemia (> 5.0\,mEq/L)

Primary Cause: Renal insufficiency is the #1 cause.
Failure to Excrete: Renal failure, aldosterone deficiency, medications (ACE inhibitors, blockers, Heparin, NSAIDs).
High Intake: Over-supplementation.
Shifts (ICF to ECF): Acidosis, burns/crush injuries, severe infections, Digoxin and Beta-blockers.
Sensitivity: The myocardium is the most sensitive tissue. Symptoms occur at $6-7\,mEq/L$ (rapid rise) or > 8\,mEq/L (gradual rise).

PAGE 53

Signs and Symptoms of Hyperkalemia

Muscles: Slows contraction; starts with leg cramps/weakness, progresses to flaccid paralysis (including respiratory).
GI: Speeds up; abdominal cramping and diarrhea.
Neuro: Irritability, anxiety.
Cardiac: Irregular pulse, bradycardia, hypotension. ECG shows flat P-wave, wide QRS, and peaked T-waves.

PAGE 54

Taking Action: Hyperkalemia

Nursing: Cardiac monitoring, safety, limit high-K foods, stop all IV/Oral K supplementation.
To Shift K Into Cells: * Beta-adrenergic agonists (Albuterol neb). * Insulin (plus Glucose to prevent hypoglycemia). * Sodium Bicarbonate (if acidosis is present).
To Remove K from the Body: * Patiromer (oral, binds K in GI). * Diuretics (e.g., Furosemide). * Dialysis (in severe cases).

PAGE 55

Evaluation Question

Scenario: Potassium level is $6.5\,mEq/L$ . What is the priority?

Correct Answer: Apply a continuous cardiac monitor.

PAGE 56

Clinical Case Study: Linda Patterson

Patient Profile: 52-year-old female, POD 1 following Total Thyroidectomy.
Assessment Findings (Vital Signs): * BP: $118/72\,mmHg$ * HR: $58\,bpm$ (Quality: Weak, thready) * RR: $20/min$
Neuromuscular Indicators: * Paresthesia of lips, nose, ears, fingers, toes. * Painful muscle cramps in thighs and calves; muscle twitching. * Trousseau Sign (Positive): Carpal spasm when BP cuff is inflated above systolic for $2\text{ minutes}$ . * Chvostek Sign (Positive): Facial twitching when tapping facial nerve below the ear. * Hyperactive Deep Tendon Reflexes.

PAGE 57

Linda Patterson Continued Assessment

GI: Hyperactive bowel sounds, abdominal cramping, diarrhea.
Cardiovascular: Weak, thready pulse.
ECG: Prolonged QT interval and prolonged ST interval.

PAGE 58

Case Study: Linda Patterson Labs

Total Calcium: $6.8\,mg/dL$
Ionized Calcium: $3.2\,mg/dL$
Albumin: $3.8\,g/dL$
Magnesium: $1.6\,mg/dL$
Phosphorus: $4.8\,mg/dL$
Vitamin D: $18\,ng/mL$
Diet: Lactose intolerant; no calcium supplements.
Current Status: Anxious; reports "tingly all over".

PAGE 59

Think About It: Hypocalcemia Analysis

Post-Thyroidectomy: Often involves accidental removal or trauma to parathyroid glands.
Neuromuscular excitability: Low calcium lowers the action potential threshold.
Why are Trousseau/Chvostek important? (Note: Indicators of tetany).
Priority Actions: Airway (laryngeal spasm) and Calcium replacement.

PAGE 60

Hypocalcemia (< 9.0\,mg/dL): Causes

Decreased Intake: Adolescents, alcoholics, poor maternal intake (breastfed babies), lactose intolerance.
Absorption Issues: Increased GI mobility; Anticonvulsants (Dilantin).
Losses: Pancreatitis, loop diuretics (Furosemide), renal failure.
Endocrine: Thyroid/Parathyroid surgery.
Other: High Phosphorus levels (inverse relationship), multiple blood transfusions (citrate binds calcium), alkalosis, and low albumin levels (most common cause).

PAGE 61

Signs and Symptoms of Hypocalcemia: Excitability

CNS: Paresthesia (perioral, toes, fingers, face).
Muscles (The Three T's): Tetany, Tremors, Twitching.
Respiratory Danger: Laryngeal stridor (Airway risk!).
Safety: Dysphagia (swallowing risk) and hyperactive DTRs.
Heart: Prolonged QT interval (risk of ventricular tachycardia), hypotension, bradycardia.
GI: Diarrhea.

PAGE 62-63

Taking Action: Hypocalcemia

Treatment: Calcium replacement, Vitamin D supplementation, and calcium-rich foods.
Environment: Reduce stimuli in the environment to prevent seizures/spasms.
Injury Prevention: General safety strategies.

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Clinical Case Study: Margaret Foster

Patient Profile: 67-year-old female with metastatic breast cancer to the bone.
Assessment Findings (Vital Signs): * BP: $108/68\,mmHg$ * HR: $58\,bpm$ (Quality: Bradycardia) * RR: $14/min$
Neuromuscular: Severe bilateral muscle weakness; decreased DTRs; confusion and lethargy. (No paresthesia).
GI: Hypoactive bowel sounds; severe constipation (no BM in $5\text{ days}$ ); abdominal distention; anorexia/vomiting.

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Margaret Foster Additional Assessment

Cardiovascular: ECG shows shortened QT interval; bradycardia with irregular rhythm; decreased cardiac output.
Renal: Polyuria (increased output); excessive thirst.

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Case Study: Margaret Foster Labs

Total Calcium: $13.8\,mg/dL$
Ionized Calcium: $6.2\,mg/dL$
Albumin: $3.5\,g/dL$
Phosphorus: $2.1\,mg/dL$
BUN: $34\,mg/dL$
Creatinine: $1.8\,mg/dL$
24-Hour I&O: Intake $1200\,mL$ ; Output $2400\,mL$ .
Status: Minimally responsive.

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Think About It: Hypercalcemia Analysis

Bone Metastasis: Bone destruction releases calcium into the blood.
Dehydration despite polyuria: High calcium interferes with ADH action in the kidneys, leading to water loss.
Emergency Interventions: Fluids and mobilization.

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Hypercalcemia (> 10.5\,mg/dL)

Clinical Status: Can be a medical emergency.
Pathophysiology: Reduced excitability of muscles and nerves.
Causes: * Hyperparathyroidism (most common). * Malignancies (bone resorption). * Prolonged immobility. * High Vitamin D intake. * Thiazide diuretics, Lithium, Theophylline, Digoxin.

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Signs and Symptoms: Hypercalcemia

CNS: Lethargy to coma; confusion; decreased attention span.
Muscles: Hyporeflexia; weakness; fatigue; decreased tone.
Heart: Short QT interval; short ST segment; increased BP; high clotting potential in lower extremities (LE).
GI: Anorexia, N/V, constipation.

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Taking Action: Hypercalcemia

Fluid Management: IV $0.9\%\,NS$ replacement; encourage drinking $3-4\,L/day$ of isotonic fluid.
Excretion: Furosemide (do NOT use thiazides).
Pharmacology: Calcitonin; Bisphosphonates (Pamidronate) for malignancy-related hypercalcemia.
Activity: Weight-bearing activities to keep calcium in bones.
Diet: Low calcium diet.

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Clinical Case Study: Thomas Rivera

Patient Profile: 48-year-old male with chronic alcoholism.
Presentation: Admitted with tremors, confusion, twitching.
Neuromuscular: Positive Chvostek and Trousseau signs; Tetany; Seizure activity witnessed.
Neurological: Disoriented, psychotic behavior, agitated.
Cardiovascular: ECG shows ventricular dysrhythmias and Torsades de Pointes.

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Case Study: Thomas Rivera Labs

Magnesium: $1.0\,mEq/L$
Calcium: $7.2\,mg/dL$
Potassium: $2.9\,mEq/L$

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Hypomagnesemia (< 1.3\,mEq/L)

Etiology: Alcoholism, malabsorption (Celiac, Crohn’s), GI loss (diarrhea, suction), and renal loss (diuretics, SIADH).
Priority Rule: Correct Magnesium levels before attempting to correct Potassium levels.

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Signs and Symptoms: Hypomagnesemia

CNS: LOC changes, hallucinations, seizures, nystagmus.
Neuromuscular: Tremores, tetany, twitching, hyperactive DTRs.
Cardio: Tachycardia, HTN, wide QRS, prominent U-wave.
GI: Dysphagia; risk of Digoxin toxicity.

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Taking Action: Hypomagnesemia

Replacement: Oral supplements or IV Magnesium Sulfate.
Warning: Infuse IV replacement slowly and use caution as Magnesium comes in many concentrations.

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Clinical Case Study: Eleanor Chen

Patient Profile: 71-year-old female with CKD Stage 5.
Vital Signs: BP $88/54\,mmHg$ ; HR $42\,bpm$ ; RR $8/min$ .
Neuromuscular: Absent DTRs; flaccid weakness.
Respiratory: Shallow, developing insufficiency.
Cardiovascular: Vasodilation; ECG with wide QRS and prolonged PR.

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Case Study: Eleanor Chen Labs

Magnesium: $6.8\,mEq/L$
BUN: $82\,mg/dL$
Creatinine: $5.4\,mg/dL$

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Hypermagnesemia (> 2.1\,mEq/L)

Main Cause: Renal impairment paired with magnesium intake (Milk of Magnesia, antacids).
Specific uses for IV Mg: Administered for seizures/eclampsia.

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Signs and Symptoms: Hypermagnesemia

Blockage: De-presses neuromuscular transmission.
Findings: Facial paresthesia, muscle paralysis, absent DTRs, respiratory failure.
Cardiac: Bony/warmth (vasodilation), severe bradycardia, tall T-waves, cardiac arrest.

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Taking Action: Hypermagnesemia

Stop all Magnesium intake.
Give fluids (if kidneys work) and loop diuretics.
Calcium Gluconate: Clinical antagonist to Magnesium; used to reverse effects on the heart.

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Critical Comparison: Magnesium

Feature	Hypomagnesemia	Hypermagnesemia
Reflexes	Hyperactive	Absent
Muscle Tone	Tetany, Twitching	Flaccid, Weak
CNS	Seizures, Psychosis	Drowsy, Coma
Cardiac	Tachycardia, Dysrhythmia	Severe Bradycardia

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Summary of Assessments

Volume Imbalances: Focus on Perfusion and Oxygenation.
Osmolality Imbalances: Focus on Cerebral Function.
Electrolyte Imbalances: Focus on Neuromuscular and Cardiac function.
General Nursing Actions (SLO 5): Follow ABCs, monitor IV sites, know replacement protocols (Slow on Pump!), and never IV push Potassium or Magnesium. Teach clients about dietary sources.