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Purpose of IV solutions
- Provide daily maintenance fluid therapy
- Replace prior deficits
- Replace concurrent losses
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Types of frequently ordered IV solutions
- Dextrose (D)
- Normal saline (NS)
- Lactated ringers (L/R) solution
- Example:
- -5D=5%
- -A number indicates the % of grams of solute per 100 mL of dextrose or 5 grams of dextrose per 100 mL of solution
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Hypotonic IV solutions
- 2.5% dextrose in water (2.5% DW)
- 0.45% NaCl (Sodium Chloride) solution 0.45 NS, 1/2 NS, or 1/2 strength NS)
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Isotonic IV solutions
- 5% dextrose in water (D5W or 5DW)
- Normal saline (NS) solution (0.9% NaCl solution)
- Lactated Ringer's solution (L/R, R/L or LRS)
- 290mOs
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Hypertonic IV solutions
- 10% dextrose in water or 10DW
- 5DW in 0.45% NaCl solution or D5W in 1/2 NS
- D5LR or D5RLS
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Determining infusion durations
- If the rode states mL per hr such as 120 mL per hr, and a liter (1000 mL) will be supplied:
- 1. Determine the hours of duration first (total mL/mL per hour)
- 2. Convert any remainder of hours to minutes using a conversion factor
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IV administration sets
- The main types of specialized IV tubing are:
- Primary (main tubing)
- Secondary, shorter tubing that connects to the primary tubing at a port
- Blood administration sets with special filters and a Y connector for NS solution
- Extension tubings that are used when more length is needed
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selection of gravity infusion administration sets
- Macrodrip (large diameter tubing)
- -DF of 10, 15, 20
- Microdrip (narrow tubing)
- -DF of 60
- -Delivers tiny drops from needlelike projection
- -60 drops/mL
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calculating flow rates for piggyback gravity
- infusions in drops per minute to infuse in less than 1 hour
- ordered: IVPB antibiotic 50 mL over 30 minutes DF 10
- 10 drops/1 mL x 50 mL/30 mins. =16.6 or 17 drops per minute
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IV intermittent solution delivery systems
- intermittent solutions may be delivered in 5 ways:
- -IV piggyback solutions
- -volume control devices (Ex: calibrated burette chamber)
- -IV (direct) push with syringe
- -syringe pumps
- -PCA (patient controlled analgesic) pumps
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adrenergic drugs
- drugs that stimulate the sympathetic nervous system
- AKA adrenergic agonists, sympathomimetics
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characteristics of adrenergic drugs
- mimic the effects of SNS NTs (catecholamines)
- -norepinephrine (NE)
- -epinephrine (EPI)
- -dopamine
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adrenergic receptors
- located throughout the body
- are receptors for the sympathetic NTs
- -Alpha-adrenergic receptors
- -beta-adrenergic receptors
- -dopaminergic receptors: respond only to dopamine
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alpha-adrenergic receptors
- divided into alpha1, alpha2 receptors
- differentiated by their location on nerves
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alpha1-adrenergic receptors
located on postsynaptic effector cells (the cell, muscle or organ that the nerve stimulates)
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alpha2-adrenergic receptors
- located on presynaptic nerve terminals (the nerve that stimulates the effector cells)
- control the release of NTs
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alpha-adrenergic agonist responses
- vasoconstriction
- CNS stimulation
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beta-adrenergic receptors
- all are located on postsynaptic effector cells
- -beta1 adrenergic receptors-located primarily in the heart
- -beta2 adrenergic receptors-located in smooth muscle of the bronchioles, arterioles and visceral organs
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beta-adregnergic agonist responses
- bronchial, GI, and uterine smooth muscle relaxation
- Glycogenolysis
- cardiac stimulation
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dopaminergic receptors
- an additional adrenergic receptor
- stimulated by dopamine
- causes dilation of the following blood vessels, resulting in increased blood flow
- -renal
- -mesenteric
- -coronary
- -cerebral
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responses to stimulation
- Cardiovascular:
- blood vessels-alpha1, beta2-constriction/dilation
- cardiac muscle-beta1-increased contractility
- AV node-beta1-increased heart rate
- SA node-beta1-increased heart rate
- GI:
- Muscle-beat2 and alpha-decreased motility
- Sphincters-alpha1-constriction
- Genitourinary:
- Bladder sphincter-alpha1-constriction
- Penis-alpha1-ejaculation
- Uterus-alpha1, beta2-alpha contraction, beta relaxation
- Respiratory:
- bronchial muscles-beta2-dilation
- liver-beta2-glycogenolysis
- pupils-alpha1-dilation
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catecholamines
- substances that can produce a sympathomimetic response
- endogenous
- -epinephrine, norepinephrine, dopamine
- Synthetic
- -dobutamine, phenylephrine
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mechanism of action: catecholamine
- direct-acting sympathomimetic
- -binds directly to the receptor and causes a physiologic response
- indirect-acting sympathomimetic
- -causes release of catecholamine from storage sites (vesicles) in nerve endings
- -catecholamine then binds to receptors and causes a physiologic response
- Mixed-acting sympathomimetic
- -directly stimulates the receptor by binding to it and indirectly stimulates the receptor by causing the release of stored NTs from vesicles in the nerve endings
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drug effects
- Stimulation of alpha-adrenergic receptors on smooth muscles results in
- -vasoconstriction of blood vessels
- -relaxation of GI smooth muscles (decreased motility)
- -constriction of bladder sphincter
- -contraction of uterus
- -male ejaculation
- -contraction of pupillary muscles of the eye (dilated pupils)
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drug effects
- Stimulation of beta1-adrenergic receptors on the myocardium, AV node, and SA node results in cardiac stimulation
- -Increased force of contraction (positive inotropic effect)
- -Increased heart rate (positive chronotropic effect)
- -Increased conduction through AV node(positive dromotropic effect)
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drug effects
- Stimulation of beta2-adrenergic receptors on the airways results in
- -bronchodilation (relaxation of the bronchi)
- Other effects of beta2-adrenergic stimulation
- -uterine relaxation
- -glycogenolysis in the liver
- -increased renin secretion in the kidneys
- -relaxation of GI smooth muscles (decreased motility)
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Treatment of asthma and bronchitis
- Bronchodilators: drugs that stimulate beta2-adrenergic receptors of bronchial smooth muscles, causing relaxation, resulting in bronchodilation
- Examples: albuterol, ephedrine, epinephrine, formoterol, levalbuterol, metaproternol, pirbuterol, salmeterol and terbutaline (used to stop premature labor-causes relaxation of uterine smooth muscle)
- Reduction of intraocular pressure and dilation of pupils: treatment of open-anlge glaucoma
- -alpha-adrengic receptors
- -Examples: epinephrine and dipivefrin
- Temporary relief of conjunctival congestion (eyes)
- -Alpha-adrengergic receptors
- -Examples: epinephrine, naphazoline, phenylephrine, tetrahydrozoline
- Treatment of nasal congestion
- -Intranasal (topical) application causes constriction of dilated arterioles and reduction of nasal blood flow, thus decreasing congestion
- -Alpha1-adrenergic receptors
- -Ex: epinephrine, ephedrine, naphazoline, oxymetazoline, phenylephrine, and tetrahydrozoline
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Vasoactive Adrenergics (Pressors, inotropes)
- Also called cardioselective sympathomimetics
- Used to support the heart during cardiac failure or shock; various alpha and beta receptors affected
- Examples: dobutamine, ephedrine, fenoldopam, methoxamine, dopamines, epinephrine, epinephrine, phenylephrine, norephinephrine
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alpha-adrenergic adverse effects
- CNS: Headache, restlessness, excitement, insomnia, euphoria
- Cardiovascular: palpitations (dysrhythmias), tachycardia, vasoconstriction, hypertension
- Other: loss of appetite, dry mouth, nausea, vomiting, taste changes (rare)
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beta-adrenergic adverse effects
- CNS: mild tremors, headache, nervousness, dizziness
- Cardiovascular: increased heart rate, palpitations (dysrhythmias), fluctuations in BP
- Other: sweating, nausea, vomiting, muscle cramps
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interactions: adrenergic drugs
- Anesthetic drugs, tricyclic antidepressants, MAOIs, antihistamines
- Thyroid preparations, antihypertensives
- Will directly antagonize another adrenergic drug, resulting in reduced effects
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nursing implications: adrenergic drugs
- assess for allergies and history of hypertension, cardiac dysrhythmias, or other cardiovascular disease
- assess renal, hepatic, and cardiac function before treatment
- perform baseline assessment of vital signs, peripheral pulses, skin color, temperature, and capillary refill; include postural blood pressure and pulse
- follow administration guidelines carefully
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nursing implications: adrenergic drugs IV administration
- check IV site often for infiltration
- use clear IV solutions
- Use and infusion pump
- Infuse drug slowly to avoid dangerous cardiovascular effects
- monitor cardiac rhythm
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Nursing implications: with chronic lung disease
- Instruct patients to avoid factors that exacerbate their condition
- encourage fluid intake (up to3000 mL/day) if permitted
- educate patients about proper dosing, use of equipment (MDI, space, nebulizer) and equipment care
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nursing implications: adrenergic drugs
- Salmeterol is indicated for prevention of bronchospasms, not management of acute symptoms
- Overuse of nasal decongestants may cause rebound nasal congestion or ulcerations
- avoid OTC or other medications because of possible interactions
- Administering two adrenergic drugs together may precipitate severe cardiovascular effects such as tachycardia or hypertension
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Nursing implications: monitor therapeutic effects (cardiovascular uses)
- Decreased edema
- increased urinary output
- return to normal vital signs
- improved skin color and temperature
- increased LOC
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Nursing implications: monitor therapeutic effects (asthma)
- Return to normal respiratory rate
- improved breath sounds, fewer crackles
- increased air exchange
- decreased cough
- less dyspnea
- improved blood gases
- increased activity tolerance
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