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 and renal injury
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
How do you treat hypotonic hypervolemic hyponatremia
Diuresis with fluid restriction (since it is caused by fluid overload)
What drugs/drug class can be used to treat SIADH and hypervolemic hyponatremia
Arginine vasopressin (AVP) receptor antagonists Conivaptan and tolvaptan
Correcting sodium more rapidly than ___ mEq/L over ___ hrs can cause ______ or _____, which can cause paralysis, seizures, & death
12 mEq/L over 24 hrs
osmotic demyelination syndrome (ODS) or central pontine myelinolysis
Tolvaptan brand name
Samsca
Tolvaptan is limited to how many days and why
less than 30 days due to hepatotoxicity
Where must tolvaptan be initiated and re-initiated
In a hospital
Side effects of tolvaptan
Thirst, nausea, dry mouth, polyuria
Tolvaptan monitoring
Rate of Na increase
Hypernatremia is sodium greater than ____ mEq/L
145 mEq/L
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
IV potassium can be fatal if administered in which ways
undiluted or IV push
When hypokalemia is resistant to treatment, what should be checked
serum magnesium
What is necessary for potassium uptake
Magnesium
When serum Mg is < __ mEq/L with life-threatening symptoms (seizures & arrhythmias), what is recommended
< 1 mEq/L
IV magnesium sulfate
When serum Mg is > 1 mEq/L 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 Phosphorous
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
Carimune NF, Flebogamma DIF, Gamunex-C, Octagam, Privigen
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
HA, nausea, diarrhea, injection site reaction, infusion reaction (facial flushing, chest tightness, fever, chills, hypotension - slow/stop infusion)
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 alpha receptors, which causes _______ & (increases/decreases) systemic vascular resistance (SVR), which increases ____
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 (DA-1 agonist)?
1-4 mcg/kg/min
Medium dopamine dose (beta-1 agonist)?
5-10 mcg/kg/min
High dopamine dose (alpha-1 agonist)?
10-20 mcg/kg/min
Epinephrine MOA
Alpha-1, beta-1, beta-2 agonist
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
BP
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)
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)
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)
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
Nesiritide MOA
recombinant B-type natriuretic peptide that binds to vascular smooth muscle and increases cGMP, resulting in vasodilation
MOA of NTG at low doses
venous vasodilator
MOA of NTG at high doses
arterial vasodilator
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 brand names
Nitropress, Nipride
Nitroprusside is not for direct injection & must be diluted with
D5W
Nitrprusside 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
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
Hypoperfusion usually in the setting of hypotension
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
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
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
Cardiogenic shock
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
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
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
Which atypical antipsychotic may be beneficial in delerium
Quetiapine
Fentanyl brand name for ICU
Sublimaze
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)
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)
Midazolam brand name
Versed
Midazolam contraindications
Use with potent 3A4 inhibitors
Midazolam can accumulate in
renal impairment (active metabolite)
Etomadite monitoring
Adrenal insufficiency
Ketamine warnings
Emergence reactions (vivid dreams, hallucinations, delirium)
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
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
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
Which drug is a non-depolarizing NMBA
Cisatracurium
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