Chapter 53: Acute & Critical Care Medicine Flashcards
Which fluids are less costly and generally have fewer side adverse reactions - crystalloids or colloids
Crystalloids
Colloids are ____ molecules (typically protein or starch) dispersed in solutions that primarily remain in the ______ space and ____ oncotic pressure
Large molecules
intravascular space
Increase
Which fluid is used when water is needed intracellularly, as these products contain “free water”
Dextrose
Which fluids are the most common drugs used for volume resuscitation in shock states
Lactated Ringers and Normal saline
Which fluid is the most commonly used colloid
Albumin
When is albumin useful
significant edema (e.g., cirrhosis)
Boxed warning for hydroxyethyl starch
avoid use in critical illness (including sepsis) due to mortality, renal injury, and coagulopathy
Which common fluids are crystalloids
D5W
Normal saline
Lactated Ringers
Multiple electrolyte injection (i.e., Plasma-Lyte A)
Which common fluids are colloids
Albumin 5%, 25% (Albutein, AlbuRx)
Dextran
Hydroxyethyl starch
Hyponatremia is Na below
< 135 mEq/L
How do you treat hypotonic hypovolemic hyponatremia
administer sodium chloride IV solutions
stop any offending agent (diuretics)
How do you treat hypotonic hypervolemic hyponatremia
common causes
Diuresis with fluid restriction (since it is caused by fluid overload)
cirrhosis, heart failure, renal failure
What drugs/drug class can be used to treat SIADH and hypervolemic hyponatremia
tx: diuresis, stop offending agent, fluid restriction Arginine vasopressin (AVP) receptor antagonists Conivaptan and tolvaptan
when is NaCl 3% an option
when Na < 120 mEq/L
or severe symptoms
Rate to correct hyponatremia
Correcting sodium more rapidly than ___ mEq/L over ___ hrs can cause ______ or _____, which can cause ________
usually 4-8 mEq/L/day
max: 12 mEq/L over 24 hrs
osmotic demyelination syndrome (ODS) or central pontine myelinolysis –> paralysis, seizures and death
Tolvaptan brand name
Samsca
Tolvaptan is limited to how many days and why
≤ 30 days due to hepatotoxicity
administration of tolvaptan
conivaptan?
tablet (PO)
IV
Where must tolvaptan be initiated and re-initiated
why?
In a hospital
close monitoring of serum Na
Side effects of tolvaptan
Thirst, nausea, dry mouth, polyuria
Tolvaptan monitoring
Rate of Na increase
risk of ODS (increase ≥ 12 mEq/L/day)
Hypernatremia is sodium greater than ____ mEq/L
what is it associated with?
145 mEq/L
water deficit and hypertonicity
Hypokalemia is potassium less than ___ mEq/L
3.5 mEq/L
Medications that can cause hypokalemia
amphotericin, insulin
A drop of 1 mEq/L in serum K below 3.5 mEq/L represents a total body deficit of ___-___ mEq
100-400 mEq
Through a peripheral line, IV potassium replacement includes a max infusion rate of ≤ ___ mEq/hr & a max concentration of ___ mEq/___ mL
10 mEq/hr
10 mEq/100 mL
> 10 requires continuous EKG monitoring
IV potassium can be fatal if administered in which ways
undiluted or IV push
never never never IV push
When hypokalemia is resistant to treatment, what should be checked
serum magnesium
Most likely cause of hyper-kalemia or magnesemia
renal dysfunction
When serum Mg is < __ mEq/L with life-threatening symptoms (seizures & arrhythmias), what is recommended
< 1 mEq/L
IV magnesium sulfate
Magnesium < 1 mEq/L with no symptoms tx
IV or IM administration
When serum Mg is > 1 mEq/L but < 1.5 without life-threatening symptoms, what can be used
oral magnesium oxide
When is hypophosphatemia considered severe
When serum phosphate is < 1 mg/dL
When serum PO4 is < 1 mg/dL, what is used for replacement
IV Phosphorus
What does IV immune globulin contain
Pooled immunoglobulin (IgG)
What are some off-label uses for IVIG
MS, myasthenia gravis, Guillain-Barre
IVIG brand names
Gammagard, Gamunex-C, Octagam, Privigen
IVIG can impact the response to what?
vaccinations
When should a slower infusion rate be used with IVIG
In renal and CV disease
IVIG boxed warnings
- Acute renal dysfunction - rare, but fatal (more likely with products stabilized with sucrose)
- Thrombosis (even without risk factors)
IVIG boxed warnings
infusion reaction (facial flushing, chest tightness, fever, chills, hypotension - slow/stop infusion)
a slower titration and premedication may be needed if hx
What is the scoring tool used to determine prognosis and estimate ICU mortality risk
The Acute Physiologic Assessment & Chronic Health Evaluation II (APACHE II)
Most vasopressors work by stimulating ____ receptors, which causes _____ & (increases/decreases) systemic vascular resistance (SVR), which increases ____
Alpha receptors
Vasoconstriction (think vasopressor PRESSES down on the vasculature)
Increases
BP
_____ is a natural precursor of NE and is recommended for use in symptomatic bradycardia
Dopamine
Low (renal) dopamine dose ?
acts on what receptors?
1-4 mcg/kg/min
DA-1 agonist
Medium dopamine dose?
acts on what receptors?
5-10 mcg/kg/min
beta-1 agonist
High dopamine dose?
acts on what receptors?
10-20 mcg/kg/min
alpha-1 agonist
Epinephrine MOA
Alpha-1, beta-1, beta-2 agonist
epinephrine brand name
Adrenalin, EpiPen
Norepinephrine brand name
Levophed
Norepinephrine MOA
Alpha-1 agonist > beta-1 agonist
Phenylephrine MOA
Alpha-1 agonist
What are the other names for vasopressin
ADH and arginine vasopressin (AVP)
All vasopressors are ____ when administered IV
Vesicants
How should vasoconstrictor extravasation be treated
phentolamine
Vasopressor side effects
Arrhythmias, tachycardia (esp DA, Epi, and vasopressin), necrosis (gangrene), bradycardia (phenylephrine), hyperglycemia (epi)
What should be monitored with all vasopressors
continuous BP
don’t use vasopressor solutions if…
discolored or precipitate
How should all vasopressors be administered
central IV line
Dose of epinephrine used for IV push
0.1 mg/mL (1:10,000 ratio strength)
Dose of epinephrine used for IM injection
1 mg/mL (1:1,000 ratio strength)
T/F: extravasation is a medical emergency with vasopressors
True, all vasopressors are vesicants and should be treated with phentolamine (alpha blocker)
Phentolamine MOA
alpha-1 blocker
When is nitroglycerin often used
When there is severe myocardial ischemia or uncontrolled HTN
Effectiveness of nitroglycerin may be limited after __-__ hrs due to ____
24-48 hrs due to tachyphylaxis (tolerance)
Nitroglycerin MOA
low doses: venous vasodilator
high doses: arterial vasodilator
Nitroprusside MOA
mixed (equal) arterial and venous vasodilator at all doses
When should nitroprusside NOT be used
active myocardial ischemia (can cause blood to be diverted away from the diseased coronary arteries - “coronary steal”)
Metabolism of nitroprusside results in:
formation of thiocyanate and cyanide (both can cause toxicity)
esp in renal or hepatic insufficiency
What can be administered to reduce the risk of thiocyanate toxicity with use of nitroprusside
Hydroxycobalamin
What can be administered to reduce the risk of cyanide toxicity with use of nitroprusside
Sodium thiosulfate
nitroprusside brand name
Nipride
NTG contraindications
SBP < 90 mmHg
Use with a PDE-5 inhibitor or riociguat
Side effects of NTG
HA, tachycardia, tachyphylaxis
What kind of container does NTG require
non-PVC container (e.g., glass, polyolefin)
Nitroprusside is not for direct injection & must be diluted with
D5W preferred
Nitroprusside can cause increased:
Intracranial pressure
If nitroprusside turns this color, it indicates degradation to cyanide
Blue
Inotropes increase:
contractility of the heart
Dobutamine MOA
Beta-1 agonist
Milrinone MOA
PDE-3 inhibitor in cardiac and vascular tissues
Which drugs are inotropes
Dobutamine & milrinone
Dobutamine may turn what color due to oxidation, but it does not indicate potency has been lost
Slightly pink
How is shock characterized?
How it is defined?
Hypoperfusion usually in the setting of hypotension
SBP < 90 or MAP < 70
General principles of treating shock
- Optimize preload with IV crystalloid bolus (PRN)
- Peripheral vasoconstrictor (alpha-1 agonist) to increase systemic vascular resistance (SVR)
- Beta-1 agonist to increase myocardial contractility & CO
First-line therapy for hypovolemic shock that is not caused by hemorrhage
Fluid resuscitation with Crystalloids
If the patient does not respond to initial crystalloid therapy in hypovolemic shock, vasopressors may be indicated, but they will not be effective unless:
Intravascular volume is adequate
Example of distributive shock
Sepsis
anaphylactic, neurogeninc
Two common causes of ICU infections
- Mechanical ventilation pushes air into the lungs for pts who cannot breathe on their own
- Foley catheters
Bundles to reduce mortality from sepsis and septic shock includes
Early administration of broad-spectrum abx & IV fluid resuscitation with IV crystalloids
How to define septic shock
persistent hypotension requiring vasopressors to maintain MAP ≥ 65 mmHg
If adequate perfusion cannot be maintained with IV crystalloids in septic shock, what is the vasopressor of choice that can be used
Norepinephrine
Sudden weight gain, inability to lie flat without becoming SOB, decreasing functionality, increasing SOB and fatigue is called acute decompensated HF & when hypotension and hypoperfusion are also present it is called
without hypotension and hypoperfusion it’s called
Cardiogenic shock
actue decompensated heart failure
Beta-blockers should only be stopped in an acute decompensated HF episode if:
hypotension or hypoperfusion is present
What is the name of the catheter that some patients with acute decompensated HF require
Swan-Ganz catheter
= pulmonary artery catheter
What does the Swan-Ganz catheter measure in acute decompensated HF?
pulmonary capillary wedge pressure (for congestion)
What treatments are used for volume overload in acute decompensated HF
Loop diuretics
possibly IV Vasodilators can be added (NTG, nitroprusside, nesiritide)
What treatments are used for hypoperfusion in acute decompensated HF
Inotropes (dobutamine, milrinone)
If the pt becomes hypotensive, consider adding a vasopressor
*avoid vasodilators since they can ↓ BP and worsen hypoperfusion
First-line for analgesia in the ICU
Opioids given IV like morphine, hydromorphone and fentanyl
____ are preferred for sedation and are associated with improved ICU outcomes
Non-BZDs like propofol and dexmedetomidine
dexmedetomidine brand name
Precedex
What is the only sedative approved for use in intubated and non-intubated pts
dexmedetomidine
how often should sedation vacations be tried?
daily
Which atypical antipsychotic may be beneficial in delerium
Quetiapine
Fentanyl brand name for ICU
Sublimaze
hydromorphone brand name
Dilaudid
Morphine brand name
Duramorph, Infumorph
dexmedetomidine MOA
Alpha-2 adrenergic agonist
dexmedetomidine side effects
Hypo/hypertension, bradycardia
Duration of infusion for dexmedetomidine should not exceed ____ hrs per FDA labeling
24 hrs
Propofol brand name
Diprivan
Propofol contraindications
Hypersensitivity to egg & soy
Propofol side effects
Hypotension, apnea, hypertriglyceridemia, green urine/hair/nail beds, propofol-related infusion syndrome (PRIS-rare but can be fatal), pancreatitis, QT prolongation
Propofol vial & tubing should be discarded within how many hours of use due to bacterial growth
12 hrs
Propofol oil-in-water emulsion provides ___ kcal/mL
1.1
Lorazepam injection can cause
propylene glycol toxicity (acute renal failure and metabolic acidosis)
lorazepam brand name
Ativan
Midazolam brand name
Versed
Midazolam contraindications
Use with potent 3A4 inhibitors
Midazolam can accumulate in
renal impairment (active metabolite)
Etomidate monitoring
Adrenal insufficiency
Ketamine warnings
Emergence reactions (vivid dreams, hallucinations, delirium)
ketamine MOA
NMDA receptor antagonist
haloperidol brand name
Haldol
quetiapine brand name
Seroquel
What are the recommended agents for prevention of stress ulcers
H2RAs and PPIs
PPIs have been associated with an increased risk of
GI infections (C.diff), fractures and nosocomial pneumonia
Which risk factors in the ICU is associated with the development of stress ulcers
Mechanical ventilation > 48 hrs
coagulopathy
sepsis, major burns, acute renal failure, high dose steroids, TBI
Inhaled anesthetics can rarely cause
malignancy hyperthermia
Which anesthetic commonly used in epidurals can be fatal if administered IV
Bupivacaine
Local anesthetic
Lidocaine (Xylocaine)
Inhaled anesthetics
desflurane (Suprane), sevoflurane
Injectable anesthetics
Bupivacaine, ropivacaine, lidocaine
lidocaine brand name as local anesthetic
Xylocaine
Desflurane brand name
Suprane
Neuromuscular blocking agents can cause
paralysis of the skeletal muscle
Patients can require the use of a NMBA agent in surgery for what reasons:
to facilitate mechanical ventilation
to manage increased intracranial pressure
to treat muscle spasms (tetany)
Patients should receive adequate what before starting and NMBA
Sedation and analgesia
Patients must be _____ while on NMBAs since they can paralyze the diaphragm
mechanically ventilated
All NMBAs must be labeled with a colored auxiliary label stating:
“WARNING, PARALYZING AGENT”
What is the only available depolarizing NMBA
Succinylcholine
Succinocholine is typically reserved for
intubation
Special care when using NMBAs includes
protecting the skin, lubricating the eyes and suction the airway frequently to clear secretions
Which anticholinergic drug can be used to reduce secretions when using NMBAs
Glycopyrrolate
medications that can enhance the effect of NMBAs
aminoglycosides
polymyxins
others: CCBs, vanco, cyclosporine
Which drug is a non-depolarizing NMBA
Cisatracurium
also atracurium, pancuronium, rocuronium, vecuronium
Cisatracurium brand name
Nimbex
Side effects for all non-depolarizing NMBAs
Flushing, bradycardia, hypotension, tachyphylaxis
How is Cisatracurium metabolized
Hofmann elimination (independent of renal and hepatic function)
Which non-depolarizing NMBA is long-acting
Pancuronium
How do systemic hemostatic drugs work
They inhibit fibrinolysis or enhance coagulation
Tranexamic acid injection brand name
Cyklokapron
Tranexamic acid tablet brand name
Lysteda
Recombinant Factor VIIa brand name
NovoSeven RT
Lysteda (tranexamic acid tablet) is approved for
Heavy menstrual bleeding
