Acute & Critical Care Medicine

Difference between crystalloids and colloid fluids

crystalloids: most of volume does not remain in the intravascular space (inside blood vessels) but moves into extravascular/interstitial space

colloids: primarily remain in intravascular space and increase oncotic pressure

Examples of crystalloids:

5% dextrose (D5W)

0.9% NaCL (NS)

Lactated Ringers (LR)

Plasma-Lyte A

Examples of colloids

albumin 5%, albumin 25%

Hespan (hydroxyethyl starch, dextran

Colloids provide (smaller/larger) intravascular volume than crystaloids

larger

T/F: Colloids are more expensive and have not shown a clear clinical benefit over crystalloids

true

Fluids most commonly used for volume resuscitation in shock states

NS and LR

lactated ringers contains:

NaCl, KCl, CaCl2, Na-lactate (which is converted to bicarbonate)

The most commonly used colloid ______ is specifically useful when there is _____ such as in conditions like _____

albumin

useful specifically when there is significant edema like in conditions like cirrhosis

T/F: Albumin can be used as a nutritional supplementation when serum albumin is low

FALSE this is now how to raise albumin

Hespan starch has a boxed warning for ____ and should only be used if other treatments are unavailable

boxed warning for mortality

Hyponatremia is usually not sympotmatic until:___ where symptoms can be

<120

symptoms can be headache, confusion, gait disturbances to seizures, coma

3 types of hyponatremia based on osmolality and their preferred treatment

hypotonic hypervolemic hyponatremia: (fluid overload): treat w/ diuresis and fluid restriction

isovolemic: diuresis, stopping offending agents, demeclocycline for SIADH off-label

hypovolemic:(caused by diuretics) stop intake of hypotonic solutions, give hypertonic (3%) sodium chloride IV

Typical treatment goal of sodium correction is ______

4-8 mEq/L/24H

Correcting sodium more rapidly than ______ can cause ________

more rapidly than 12 mEq/L/24H

can cause osmotic demyelination syndrome or central pontine myelinolysis (leading to paralysis, seizures, death)

Treatment for SIADH, hypervolemic hyponatremia

conivaptan and tolvaptan (AVP receptor antagonists)

tolvaptan drug class

arginine vasopressin receptor antagonists (AVP antagonists)

Do not use Samsca beyond ________

30 days

(tolvaptan)

T/F: tolvaptan must be initiated and re-initated in the hospital

true (boxed warning)

boxed warning on Samsca

(tolvaptan)

initiated and re-initiated in a hospital

overly rapid correction of hyponatremia (>12 mEq/L/24H is assoc. w/ ODS (life-threatening)

warnings and side effects with tolvaptan

hepatotoxicity

SE: thirst, nausea, dry mouth, polyuria

Tolvaptan is administered ___ for no more than ____ (due to ____)

PO (tablet)

no more than 30 days due to hepatotoxicity

hypovolemic hypernatremia is typically caused by:

dehydration, vomiting, diarrhea (treat w/ fluids)

hypervolemic hypernatremia is caused by

intake of hypertonic fluids (treat w/ diuresis)

isovolemic euvolemic hypernatremia is usually caused by:

Diabetes insipidus which can decrease ADH

(it is treated w/ desmopressin)

a drop of ____ below 3.5 mEq/L represents a total body deficit of ______ in potassium

a drop of 1 mEq/L in serum K below 3.5 represents a deficit of 100-400 mEq

T/F: The oral route is preferred for potassium when feasible

true

Max infusion rate of potassium and max concentration

10 mEq/hr, max concentration of 10 mEq/100mL

T/F: IV potassium should be adminstered undiluted or via IV push

False: These administration routes are LETHAL

NEVER administered undiluted or via IV push

______ is necessary for potassium uptake

magnesium

When someone is hypokalemic and has low magnesium, _____ should be corrected first

magnesium should be replaced first (M comes before P in the alphabet)

Magnesium replacement via _____ is recommended

IV magnesium sulfate

symptoms of hypomagnesium

seizures, arrx

T/F: Hypophosphatemia is considered severe and is usually symptomatic

True

Hypophosphatemia is replaced via ____

IV phosphorus

Uses for IVIG

MS, myasthenia gravis, Guillain-Barre syndrome, immunodeficiency conditions

IVIG can impair response to

vaccination

Boxed warning with IVIG products

acute renal dysfunction: is more likely w/ products stabilized w/ sucrose

thrombosis can occur even without RFs

Octagam and Privigen are brans of

IVIG products

When dosing IVIG, remember:

use a slower infusion rate in renal and CV disease patients

do not freeze, shake or heat

side effects of immunoglobulin

infusion reaction (facial flushing) chest tightness, fever, chills, hypotension - slow/stop infusion

(may use premedication or slower titration)

Score used to estimate ICU mortality risk

APACHE II

most vasopressors work by stimulating _____ which causes _____

stimulating alpha receptors causing peripheral vasocontriction (think pressing down on the vasculature)

this increases SVR) which increases BP

vasopressors that stimulate beta receptors can increase ______

HR and CO

Phenylephrine is a ______ that increases _______ without _____

pure alpha-agonist that increases SVR without increasing HR

Mixed alpha- and beta-agonists include

epinephrine and norepinephrine

mixed alpha- and beta-agonists increase :

SVR, CO, and HR

dopamine is a natural precursor of

norepinephrine

At a low dose (____-____) dopamine is a _____

Low (renal) dose: 1-4mcg/kg/min

dopamine is a dopamine-1 agonist

at a medium dose (__-____) dopamine is a ____

medium dose: 5-10 mcg/kg/min

dopamine is a beta-1 agonist

at a high dose: (__-____) dopamine is a _____

high dose: 10-20 mcg/kg/min

dopamine is an alpha-1 agonist

Dopamine from low to medium to high dose becomes a

dopamine-1 agonist, beta-1 agonist, alpha-1 agonist

(DBAA)

Vasostrict drug class

(vasopressin)

vasopressin receptor agonist

known as arginine vasopressin (AVP) and antidiuretic hormone ADH

levophed drug class

(norepinephrine)

alpha-1 agonist > beta-1 agonist activity

all vasopressors are _____, when administered IV. This can be treated w/ ______

all vasopressors are vesicants

extravasation can be treated w/ phentolamine

Extravasation from vasopressors can be treated with

phentolamine

Epinephrine IM injection (epipen) strength or compounding IV products is:

1mg/mL (1:1,000)

Epinephrine used for IV push is

0.1mg/mL, 1:10,000 ratio strength

Side effects of Vasopressors

arrx, tachy, necrosis (gangrene), bradycardia, phenylephrine, hyperglycemia (epi)

T/F: Patients on vasopressors should be monitored continuously for BP and MAP

true

Phentolamine drug class

alpha-1 blocker (antagonizes effects of the vasopressor

what to do if extravasation occurs?

stop infusion, don't dc needle/cannula, don't flush the line, aspirate the drug

phentolamine can be given

NG ointment is sometimes used if phentolamine is unavailable

Effectiveness of nitroglycerin for myocardial ischemia or uncontrolled HTN may be limited to ____ due to ______

24-48H due to tachyphylaxis (nitrate)

Nitroprusside drug class

mixed (equal) arterial and venous vasodilator at al doses

T/F: Nitroprusside has a greater effect on BP than Nitroglycerin

true

T/F: Nitroglyceride can be used in active myocardial ischemia

False: should NOT be used here because it can cause blood to be diverted away from diseased coronary arteries (coronary steal)

metabolism of nitroprusside results in

thiocyanate and cyanide formation

_______ can be administered to reduce the risk of _____ toxicity from nitroprusside

hydroxocobalamin can reduce the risk of thiocyanate toxicity or treat cyanide toxicity

Sodium thiosulfate is used for

cyanide toxicity

Drug used for cyanide toxicity

sodium thiosulfate (nithiodote (+sodium nitrite)

Nitroglycerin is a ____ at low doses_ and a _______ at high doses

low doses: venous dilator

high doses: arterial vasodilator

T/F: Nitroprusside must be further diluted

true

Dilute nitroprusside with ____

D5W

Pharmacists should be warned that nitroprusside can increase

increase ICP

Contraindications to NG

SBP <90, use with PDE-5 inhibs

NG requires a ____ container

non-PVC container (exe. glass, polyolefin)

There is increased risk of cyanide/thiocyanate toxicity in_____- with nitroprusside

renal and hepatic impairment

Nipride requires ____ during administrations

light protection

Only use ___ solutions with Nipride, as a blue color indicates _____

clear solutions

blue color indicates degradation to cyanide

Inotropes work by

increasing contractility of the heart

Dobutamine is a ______ that works by increasing ____

dobutamine is a beta-1 agonist

works by increasing HR and force of contraction (therefore increasing CO)

(also has weak beta-2 and alpha-1 agonism but is less important)

Milrinone is a _____ that produces ____ effects

it is a phosphodiesterase-3(PDE-3)inhibitors in cardiac and vascular tissue

produces inotropic effects (vasodilation)

Vasodilators include:

nitroglycerin, nitroprusside

inotropes include:

Dobutamine

Milrinone

notes regarding dobutamine

may turn slightly pink due to oxidation, but potency is not lost

Shock usually is characterized by:

hypoperfusion (usually from hypotension): <90SBP or MAP<70

4 types of shock

hypovolemic (exe. hemorrhagic)

distributive (ex. septic, anaphylactic)

cardiogenic (ex. post-myocardial infarction)

obstructive (ex. massive pulm. embolism)

First line treatment for hypovolemic shock

fluid resuscitation with crystalloids when it is not caused by hemorrhage

blood products when there is hypovol shock due to bleeding

vasopressors may be indicated if they do not respond, but will not be effective unless intravascular volume is adequate

T/F: If the volume cannot be correct in a patient with hypovolemic shock, vasopressors can be given

False: Vasopressors will NOT be effective unless intravascular volume is adequate. Vasopressors can be given if patients don't respond to initial crystalloid/blood product therapy (fluid challenge)

Sepsis and anaphylaxis are examples of _____ shock

distributive

sepsis is defined as _______ caused by ______

life threatening organ dysfunction

caused by dysregulated host response to infection

T/F: NEWS and SIRS criteria are recommended over the qSOFA assessment for Sepsis

true

In sepsis, target a MAP of _____

65 or higher

MAP equation

MAP = [(2 x DBP) + SBP]/3

General principles in treating sepsis

target MAP of 65+mmHg

optimize preload w/ IV crystalloids (LR preferred)

alpha-1 agonist to increase SVR (peripheral vasoconstriction)

beta-1 agonist to increase contractility and CO

(squeeze the pipe (alpha 1) and kick the pump (beta 1)

Septic shock is:

sepsis in presence of persistent hypotension, requiring vasopressor to maintain MAP 65+

(and serum lactate 2+ despite adequate fluid resus)

Bundles in surviving sepsis campaign include interventions like:

early administration of broad-spectrum Antibiotics

fluid resuscitation w/ IV crystalloids

Vasopressor of choice in septic shock

norepinephrine (levophed)

Commonly used in addition to norepinephrine in septic shock

vasopressin

Cardiogenic shock is:

acute decompensated heart failure (ADHF: worsening HF sx)

+ hypotension and hypoperfusion also present

Drugs that can worsen HF/cause ADHF

negative inotropes (non-DHP CCBs

drugs that cause NSAIDS

cardiotoxic drugs