Intro to Pharmacology/Fluids & Electrolytes- Week 2

Nursing Process

• a research-based organizational framework for professional nursing practice

• flexible, adaptable, and considered the major systematic framework for professional nursing practice

• requires critical thinking (clinical reasoning and clinical judgement)

• ongoing and constantly evolving process

Diagnosis

Used to communicate and share information about the pt and the pts experience. Common nursing diagnoses related to drug therapy develop from data associated with:

• deficient knowledge

• risk of injury

• non adherence

• various disturbances, deficits,

• other problems or concerns related to drug therapy

Planning- GOALS

• identification of goals and outcome criteria

Goals:

• objective, measurable, and realistic, with an established time period for the achievement of the outcomes that are specifically stated in the outcome criteria

Planning- OUTCOME CRITERIA

• concrete descriptions of pt goals

• expectation of behaviour

• provide a standard for measuring movement toward goals

Implementation

• initiation and completion of specific nursing actions

• based on nurse’s judgement and knowledge (scope of practice)

• statements of interventions include frequency, specify instructions, and any other pertinent information

• pt safety is paramount here (e.g., 10 rights of Med Admin)

3 P’s of Med Administration

Pull, Pour, Put away

Evaluation

• systematic, ongoing, and dynamic part of the nursing process

• determining the status of the goals and outcomes of care

• monitoring the pt’s response to drug therapy

• therapeutic, expected, and toxic responses

• documentation must be accurate, clear and concise

• Did you remember your pain scale?

Monitoring the Effects of a Medication

the 1-hour rule (check clinical response), medical equipment needed, adverse effects/events

Drug

Any chemical that affects the physiological processes of a living organism

Pharmacology

broadest term for the study or science of drugs

Chemical name

describes the drug’s chemical composition and molecular structure

Generic name (nonproprietary, official name)

name given to a drug approved by Health Canada

Trade name (proprietary name)

the drug has a registered trademark; use of the name is restricted by the drug’s patent owner (usually the manufacturer)

Therapeutic Class

e.g., analgesic, antipyretic

Pharmacological Class

e.g., long-acting corticosteroids,

Pharmaceutics

drug dosage form:

• topical

• enteral

• parenteral

Enteric coated tablets

Combination drugs

Time release technology

Drug delivery

the route and dosage of a medication

Pharmacodynamics

The study of what the drug does to the body. The mechanism of drug actions in living tissues.

• therapeutic response

• receptor interactions

• enzyme interactions

• Drug concentration VS pharmacological response

• Mechanism of action

  • receptor interactions: Agonist VS Antagonist

  • Enzyme interactions

  • nonspecific interactions

Pharmacotherapeutics (Clinical Pharmacology)

Factors Influencing Drug Effects

• drug interactions: synergistic effect, antagonistic, incompability

• tolerance and dependece

• drug concentration

• pt condition

• teratogenic effect

• drug polymorphism

Pharmacokinetics

• the study of what the body does to the drug

• from the time drug is put into the body until the parent drug and metabolites have left the body

  • ADME

Absorption - Pharmacokinetics

• bioavailability

• first-pass effect (GI tract)

• Depending on the Routes:

  • enteral route

• Non-first pass routes

  • sublingual and buccal routes

  • parenteral route: ID, SC, IV, IM, intrathecal, intra-articular intra-artierially.

  • topical route

  • transdermal route

  • inhalation route

Enteral Route

the drug is absorbed into the systemic circulation through the oral mucosa, or mucosa of the stomach, small intestine, or large intestine

• oral (PO)

• sublingual (SL)

• buccal (SB)

• rectal (PR)

Topical

• skin (including transdermal patches)

• eyes

• ears

• nose

• lungs (inhalation)

Parenteral Route

• Intravenous (IV)

  • fastest due to direct delivery into the blood circulation

• Intramuscular (IM)

• Subcutaneous (SC)

• Intradermal (ID)

• Intrathecal

• Intra-articular

Distribution - Pharmacokinetics

transport of a drug by the bloodstream to the drug’s site of action

Metabolism - Pharmacokinetics

• biotransformation

• liver is the most important site for metabolism

• liver breaks drug down into metabolites, cytochrome p450 system

• helps prevent medications from causing adverse effects

Excretion - Pharmacokinetics

• elimination of drugs from the body

• primary organ responsible is kidney

• liver and bowel also play a role

• renal excretion

• biliary excretion

Half-life (Pharmacokinetics Variables)

time required for half of a drug to be removed from the body

Peak level

highest blood level of a drug

Trough level

lowest blood level of a drug

Toxicity

occurs if the peak blood level of the drug is too high

Types of Therapy (pharmacotherapeutics):

• acute

• maintenance

• supplemental

• palliative

• supportive

• prophylactic

• empirical

Monitoring (Pharmacotherapeutics)

Therapeutic effect, adverse effects, idiosyncratic effect

Medication Errors

any preventable event that may cause or lead to inappropriate medication use or pt harm while the med is in the control of the health care provider, patient, or consumer.

• High alert medication?

• Independent double checking?

• Single dose systems

• Automation

Legal Nursing Considerations

• nursing practice standards- medication management standards

• scope of practice

• Nurse Practice Act

• Case law or common law consisting of prior court rulings also affect professional nursing practice

• CNA is the national voice for nurses

• Accreditation Canada requires accredited hospitals to fulfill certain standards in regard to nursing practice

Considerations for Older Adult Patients

• older adult: older than age 65 years

• high use of medications

• polypharmacy

• nonadherence

• increased incidence of chronic illnesses

• sensory and motor deficits

Homeostasis

state of equilibrium in the internal environment of the body, naturally maintained by adaptive responses that promote healthy survival

Water content of the body

50% to 60% of body weight in adults, 45% to 55% in older adults, 70% to 80% in infants. Can vary with gender, body mass, and age

Electrolytes

Substances whose molecules dissociate into ions (charged particles) when placed into water

Cations

positively charged

• sodium Na+

• potassium K+

• Calcium Ca+

• Magnesium Mg+

Anions

negatively charged

• bicarbonate HCO3-

• chloride Cl-

• phosphate P04-

Intracellular Fluid (ICF)

inside cell, K+ most concentrated

Extracellular fluid (ECF)

intravascular (plasma), interstitial (IF- between cells, vessels, tissues), Transcellular

Osmosis

• movement of H20 from low to high concentration (fluid only)

• passive transport

• across permeable/semi-permeable membranes

• requires no outside energy

• measurement of osmolality

• osmotic movement of fluids

Diffusion

• both fluids and solutes move from high concentration to low concentration

• move with concentration gradient

• net movement of molecules stop when the concentrations are equal in both areas

• simple diffusion requires no external energy

Facilitated Diffusion

• involves use of a protein carrier in the cell membrane

• requires no energy

Active Transport

• a process requiring energy in which molecules move against the concentration gradient

Hydrostatic Pressure

• force within a fluid compartment

• pushes H20 to ECF

Oncotic Pressure

• is osmotic pressure exerted by colloids in solution

• pulls H20 into capillaries

Fluid Spacing

Hypovolemia

• Fluid Volume Deficit

• abnormal loss of normal body fluids (diarrhea, fistula drainage, hemorrhage), inadequate intake, or plasma-to-interstitial fluid shift

• treatment: replace water and electrolytes with balanced IV solutions

Hypervolemia

• fluid volume excess

• excessive intake of fluids, abnormal retention of fluids (HF), or interstitial-to-plasma fluid shift

• treatment: remove fluid without changing electrolyte composition or osmolality of ECF

Renal and Adrenal Regulation- RAAS

• Renin-Angiotensinogen-Angiotensin-Aldosterone

• Retention of Na and H20

Hypothalamus and Pituitary

• sense high serum osmolality/ High Na

• triggers ADH

• retains water

Heart and Blood Vessels

• high volume causes ANF, BNP which inhibits ADH, stop RAAS

• Thus excretion of water through urine

Age-related Considerations: Fluids & Electrolytes

• structural changes in kidneys decrease the ability to conserve water

• hormonal changes lead to a decrease in ADH and ANP

• loss of subcutaneous tissue leads to increased loss of moisture

• reduced thirst mechanism results in decreased fluid intake

• nurse must assess for these changes and implement treatment accordingly

Normal pH of body fluids

• 7.35-7.45

• acidity or basicity of blood

Respiratory Acidosis

• hypoventilation

• COPD or diabetic patients at risk

Respiratory Alkalosis

• hyperventilation

Buffer System

Act quickly, 3 major buffer systems:

• bicarbonate-carbonic acid buffer system

• Phosphate buffer system

• Protein buffers

Respiratory System

• regulates carbonic acid by eliminating or retaining C02

• increase in C02 or H+ stimulates respiratory centre

• hypo/hyper ventilation

Renal System

• long-term regulation of acid-base balance

• kidneys eliminate nonvolatile acids

• regulate bicarbonate (HC03) in ECF

• sluggish

• selectively excrete or retain H+ to maintain pH

Sodium Na+

• 135-145 mmol/L

• imbalances are typically associated with parallel changes in osmolality

• Plays a major role in

  • ECF volume and concentration

  • Generation and transmission of nerve impulses

  • acid-base balance

Hypernatremia Causes

water deficit = higher concentration of Na+. Elevated serum sodium occurring with water loss or sodium gain, causes hyper osmolality leading to ccellular dehydration, primary protection is thirst from hypothalamus

• decreased ADH

• hyperosmolar IV fluids administration

• hyperglycemia

• increased water loss

• sodium intake

Hypernatremia Clinical Manifestation

• thirst

• lethargy

• agitation

• seizures

• coma

• impaired LOC

kidneys excrete excess Na+ in urine

Hypernatremia Management

• treat underlying cause

• if oral fluids cannot be ingested, IV solution of 5% dextrose in water or hypotonic saline

• diuretics

Hyponatremia

water excess = dilute concentration of Na+. Decreased serum sodium occurring with water excess or reduced sodium, causes hypo osmolality leading to cellular swelling, bodily fluids are diluted and the cells swell from decreased ECF osmolality

Hyponatremia Causes

• results from reduced sodium-containing fluids

• excessive water intake

• syndrome of inappropriate antidiuretic hormone secretion (SIADH)

Kidneys reabsorb Na+ and retain H20

Hyponatremia Clinical Manifestations

• confusion

• nausea

• vomiting

• seizures

• coma

Hyponatremia Management

• caused by water excess

• fluid restriction is needed

• severe symptoms (seizures)

• give small amount of IV hypertonic saline solution (3% NaCl)

• abnormal fluid loss

• fluid replacement with sodium-containing solution

Potassium K+

• 3.5-5.0 mmol/L

• Major ICF cation

Necessary for:

• transmission and conduction of nerve and muscle impulses

• cellular growth

• maintenance of cardiac rhythms

• acid-base balance

Potassium Sources

• fruits and veggies (bananas and oranges)

• salt substitutes

• potassium medications (PO, IV)

• stored blood

Potassium- Excretion/Loss

• kidney

• stool

• sweat

Hyperkalemia

• high serum potassium level

• all patients with clinically significant hyperkalemia should be monitored electrocardiographically to detect dysrhythmias and monitor therapy’s effects

Hyperkalemia Causes

• massive intake

• impaired renal excretion

• shift from ICF to ECF

• most common in renal failure

Hyperkalemia Manifestations

• MSK

• CNS

• Cardiac

• GI

Hyperkalemia Management

• discontinue oral and parenteral K intake

• increase elimination of K (diuretics, dialysis, Kayexalate)

• increase fluid intake

• ECF monitoring

• Force K from ECF to ICF by IV insulin or sodium bicarbonate

• reverse membrane effects of elevated ECF potassium by administering calcium gluconate IV

• Hemodialysis

Hyperkalemia- MURDER

• murder/muscle weakness

• decreased urine output

• respiratory failure

• decreased heart contractility

• early sign twitching/ m. cramps

• heart rhythm changes

Hypokalemia

• low serum potassium level

• the incidence of potentially lethal ventricular dysrhythmias is increased in hypokalemia

Hypokalemia Causes

• abnormal losses of K+ via the kidneys or GI tract

• magnesium deficiency

• metabolic alkalosis

Hypokalemia Manifestations

• most serious are cardiac

• skeletal muscle weakness (legs)

• weakness of respiratory muscles

• decreased GI motility

• impaired regulation of arteriolar blood flow

Hypokalemia Management

• K+ supplements orally or IV

• general rate of infusion is 10mmol/hr

• to prevent hyperkalemia and cardiac arrest

Hypokalemia 7 L's

• Lethargic

• Low shallow resps

• Lethal heart rhythm

• Lots of urine

• Leg cramps

• Limp muscles

• decreased BP and decreased HR

Calcium Ca+

• 2.25-2.75 mmol/L

• more than 99% combined with phosphorus and concentrated in skeletal system

  • transmission of nerve impulses

• Myocardial contractions

• blood clotting

• formation of teeth and bone

• muscle contractions

Calcium- balance controlled by:

• parathyroid hormone

• calcitonin

• vitamin D

Calcium Sources

• ingested foods

• dairy products

• green leafy

• vegetables

Hypercalcemia Causes

high serum calcium level, when too much calcium is in the blood the body suppresses the release of parathyroid hormone

• hyperparathyroidism (2/3 of cases)

• malignancy

• vitamin D overdose

• prolonged immobolization

Hypercalcemia Manifestations

• decreased memory

• confusion

• dysrhythmias

• disorientation

• fatigue

• constipation

• renal calculi

Hypercalcemia Management

• excretion of Ca with loop diuretic

• hydration with isotonic saline infusion

• synthetic calcitonin

• mobilization

Hypercalcemia- WEAK

• muscle weak

• ECG changes

• abdomen distention/constipation

• kidney stones

Hypocalcemia Causes

high serum calcium level, calcium levels are monitored by the parathyroid which will promote the transfer of calcium into the plasma when needed. PTH also promotes the kidney and intestine to reabsorb calcium.

• decreased production of PTH

• acute pancreatitis

• multiple blood transfusions

• decreased intake

• laxative abuse

Hypocalcemia Manifestations

• positive Trousseau’s sign and Chvostek’s sign

• Laryngeal stridor

• tingling around the mouth or in the extremities

• tetany

• cardiac manifestations

• CNS manifestations

Hypocalcemia Management

• treat cause

• oral or IV calcium supplements

• treat pain and anxiety to prevent hyperventilation-induced respiratory alkalosis

Hypocalcemia- CRAMPS

• convulsions

• reflexes

• hyperactive

• arrhythmias

• muscle spasms

• positive Trousseau’s/Chvostek

• sensation (numbness/tingling)

Phosphate (PH+)

• 1.12-1.45 mmol/L

• is a primary anion in the ICF and is essential to the function of muscle, RBCs and nervous system

• hyperphosphatemia is an elevated serum phosphus level

  • acute or chronic renal failure can lead to hyperphosphatemia

• hypophosphatemia (low serum phosphate) is seen in the pt who is malnourished or has a malabsorption syndrome

• 85% exists in bones, teeth. 15% in soft tissue

Magnesium

• 0.74-1.07 mmol/L

• up to 60% is stored in the bone

• factors that regulate Ca balance seem to influence Mg balance

• the myoneural junction

• essential for cardiac function

• relaxes, makes you poop, etc

Hypomagnesium- TWITCH

• + T & C test

• increased deep T reflex

Positive Trousseau’s sign and Chostek’s Sign

manifestation and assessment of hypocalcemia and hypomagnesemia

Protein (Albumin) Causes

normal range: 64-86G/L

• Colloidal oncotic pressure

• Hypoproteinemia VS Hyperproteinemia

• Protein imbalances can lead to hypoproteinemia

• Causes: anorexia, malnutrition, starvation, fad dieting, and poorly balanced vegetarian diets

Protein (Albumin) Clinical manifestations

edema (from decreased oncotic pressure), slow healing, anorexia, fatigue, anemia, and muscle loss that results from the breakdown of body tissue to meet the body’s need for protein

Protein (Albumin) Management

high carb diet, high protein and dietary protein supplement