acute/critical care

When are dextrose-containing products used?

when water is needed "intracellularly bc they contain "free water"

Which fluids are used for volume resuscitation in shock states?

lactated ringer's

normal saline

What is the most commonly used colloid?

albumin

When is albumin (a colloid) used?

when there is significant edema (cirrhosis)

When should albumin not be used?

for nutritional supplementation when serum albumin is low

When should hydroxyethyl starch (a colloid) be used?

only if other treatments are unavailable due to its boxed warning for mortality

Crystalloid common fluids

- 5% dextrose (D5W)

- 0.9% NaCl (NS0

- lactated ringer's

- plasma-lyte A

colloid common fluids

- albumin

- dextran

- hydroxyethyl starch

When is hyponatremia symptomatic?

when sodium is <120 mEq/L

hypotonic hypervolemic hyponatremia (cause + tx)

caused by fluid overload (cirrhosis, heart failure, renal failure)

tx: diuresis with fluid restriction

hypotonic isovolemic (euvolemic) hyponatremia (cause + tx)

caused by syndrome of inappropriate antidiuretic hormone (SIADH)

tx: diuresis, restricting fluids and stopping drugs that induce SIADH

- demeclocycline can be used off-label for SIADH

hypotonic hypovconivaptanmolemic hyponatremia (cause + tx)

caused by diuretics, salt wasting syndromes, adrenal insufficiency, blood loss, v/d

tx: correct underlying causes and stop intake of hypotonic solutions

- hypertonic (3%) sodium chloride IV: acute hyponatremia, severe symptoms and/or Na <120

Why should hyponatremia not be corrected too quickly?

more rapidly than 12 mEq/L/24 hours can cause osmotic demyelination syndrome (ODS) or central pontine myelinolysis -> paralysis, seizures, death

What can be administered to reduce water diuresis and help avoid overcorrection of hyponatremia?

desmopressin

What can be used to treat SIADH and hypervolemic hyponatremia?

arginine vasopressin (AVP) receptor antagonists

- conivaptan

- tolvaptan

conivaptan (Vaprisol) warning

overly rapid correction of hyponatremia is associated with ODS

tolvaptan brand name

Samsca

tolvaptan dosing

PO

limited to <=30 days due to hepatotoxicity

tolvaptan boxed warnings

initiated and re-initiated in a hospital with close monitoring of Na

overly rapid correction of hyponatremia is associated with ODS

tolvaptan warnings

hepatotoxicity (avoid >30d of use)

tolvaptan side effects

thirst, nausea, dry mouth, polyuria

tolvaptan monitoring

rate of Na increase, BP

Management of hypokalemia

treat underlying cause (medications such as amphotericin, insulin) and administer potassium

- oral is preferred

Safe recommendations for administration of IV potassium through peripheral line

- max infusion rate <=10 mEq/hr and maxd concentration of 10 mEq/100mL

- fatal if administered undiluted or IV push

What to do if hypokalemia is resistant to treatment

serum magnesium should be checked

magnesium is necessary for potassium uptake

replace magnesium first

Common causes of hypomagnesemia

chronic alcohol use

diuretics

amphotericin B

When is IV magnesium sulfate replacement recommended?

when serum Mg is <1 mEq/L + life threatening symptoms (seizures, arrhythmias)

When is magnesium oxide used for hypomagnesemia?

when serum Mg is >1 mEq/L and <1.5 mEq/L

PO magnesium replacement

When is hypophosphatemia considered severe?

symptomatic when serum phosphate is <1 mg/dL

IV phosphorus used to replacement

What is incentive spirrometry?

technique used to facilitate lung expansion in pts with atelectasis

faciliates deep breathing

What is IV immunoglobulin extracted from?

the plasma of a thousand or more blood donors (min)

What is IV IG used for?

immunodeficiency conditions

multiple sclerosis

myasthenia gravis

Guillain-Barre syndrome

IV IG brand names

Gammagard

Gamunex-C

Octaga,

Privigen

IV IG administration

use a slower infusion rate in renal and CV disease patients

do not freeze, shake, or heat

IV IG boxed warnings

acute renal dysfunction (more likely with products stabilized with sucrose

thrombosis

IV IG side effects

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

renal failure

blood dyscrasias

Why should patients be asked about past IVIG infusions?

a slower titration and premedication may be needed

Why should vaccinations be spaced out with IVIG?

IVIG treatment can impair the response to vaccination

Dopamine dosing

dopamine stimulates different receptors depending on the dose

- low (renal) dose: 1-4 mcg/kg/min -> dopamine 1 agonist (renal vasodilation

- medium dose: 5-10 mcg/kg/min -> beta 1 agonist (pos inotropic effects)

- high dose: 10-20 mcg/kg/min -> alpha 1 agonist (vasopressor)

vasopressor boxed warnings

all vasopressors are vesicants when administered IV

treat extravastation with phentolamine

What is used to treat extravastation of vasopressors?

phentolamine

vasopressor side effects

arrhythmias, tachycardia, necrosis (ganrene), bradycardia (phenylephrine), hyperglycemia (epinephrine)

vasopressor monitoring

continuous BP

epinephrine dosing for IV push

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

epinephrine dosing for IM injection or compounding IV products

1mg/min (1:1,000 ratio strength)

epinerphrine (adrenaline) MOA

alpha 1

beta 1

beta 2 agonist

norepinephrine (Levophed) MOA

Alpha-1 agonist > beta-1 agonist activity

phenylephrine MOA

alpha 1 agonist

vasopressin MOA

vasopressin receptor agonist

vasopressors MOA

alpha receptors -> peripheral vasoconstriction & increases systemic vascular resistance (SVR) -> increases BP

beta receptors -> increase heart rate and cardiac output

When is ntroglycerin used as a vasodilator?

active myocardial ischemia or uncontrolled hypertension (effectiveness limited to 24-48 hours due to tachyphylaxis)

nitroglycerin MOA

low doses = venous vasodillator (preload)

high doses = arterial vasodilator (afterload)

nitroglycerin contraindications

SBP <90 mmHg

use with PDE-5 inhibitors or riociguat

nitroglycerin side effects

headache

tachycardia

tachyphylaxis (within 24-48 hours)

What container is required for nitroglycerin?

non-PVC container (glass, polyolefin)

nitroprusside (Nipride) MOA

mixed arterial and venous vasodilator

nitroprusside (Nipride) boxed warnings

metabolism produces cyanide and thiocyanate = toxicity

excessive hypotension

not for direct injection (dilute with D5W)

What is preferred to be dilated with nitroprusside (Nipride)?

D5W

nitroprusside (Nipride) warnings

increased ICP

nitroprusside (Nipride) side effects

headache

tachycardia

thiocyanate/cyanide toxicity (increased risk in renal and hepatic impairment)

nitroprusside (Nipride) characteristics

requires light protection during administration

use only clear solutions (blue color - degradation to cyanide = do not use)

What does IV inotrope do?

increase the contractility of the heart

dobutamine MOA

beta 1 agonist

milrinone MOA

phosphodiesterase-3 inhibitor

inotrope monitoring

continuous BP and ECG monitoring

HR

Can you still use dobutamine that has oxidized to a pink color?

Yes potency is not lost

What is shock characterized by?

hypoperfusion, usually in the setting of hypotension

First line treatment for hypovolemic shock that is not caused by hemorrhage?

fluid resuscitation with crystalloids

When would vasopressors be effective in hypovolemic shock?

if intravascular volume is adequate

What is an example of distributive shock?

septic, anaphylactic, neurogenic shock

What is sepsis?

a life-threatening organ dysfunction caused by a dysregulated host response to infection

General principles for treating septic shock

Target a mean arterial pressure (MAP) of > 65 mmHg

MAP = [(2XDBP) + SBP]/3

Fill The Tank

Optimize preload with IV crystalloid bolus (as needed)

Squeeze The Pipes

Peripheral vasoconstrictor (alpha-1 agonist) to INCREASE systemic vascular resistance (SVR)

Kick The Pump

Beta-1 agonist to INCREASE myocardial contractility and cardiac output (CO)

What are the two common causes of ICU infections?

1. mechanical ventilation: pushes air into the lungs for patients who cannot breathe on their own (increased time on ventilator = increased risk of infection (lung infections))

2. indwelling urinary catheter (increased time with foley catheter = increased risk of bladder infection)

What is septic shock?

spesis with persistent hypotension requiring a vasopressor to maintain MAP >=65 mmHg

What is used to reduce mortality from sepsis and septic shock?

early administration of broad-spectrum antibiotics and fluid resuscitation with IV crystalloids

What is the vasopressor of choice in septic shock?

norepinephrine

When would beta blockers be stopped in acute decompensated heart faliure?

if hypotension or hypoperfusion is present (aka during cardiogenic shock)

Treating ADHF: edema, jugular venous distention, ascites = volume overloaded

loop diuretics

IV vasodilators (NTG, nitroprusside)

Treating ADHF: decreased renal function, altered mental status, cool extremities = hypoperfusion

inotropes (dobutamine, milrinone)

hypotensive = add vasopressor (dopamine, norepinephrine, phenylephrine)

Treating ADHF: volume overloaded and hypoperfusion

combo agents of:

- loop diuretics

- vasodilators

- inotropes

- vasopressor

What are first line analgesics in the ICU?

IV opioids ( morphine, hydromorphone, fentanyl)

What is analgesia-based sedation?

sedation strategy that uses analgesia first to relieve pain and discomfort

What is used for the management of agitation?

benzodiazepines (lorazepam, midazolam)

non-benzodiazepines (propofol, dexmedetomidine)

What is preferred for sedation and associated with improved ICU outcomes?

non-benzodiazepines (propofol, dexmedetomidine)

What is the approved sedative for intubated and non-intubated patients?

dexmedetomidine (Precedex)

What is recommended to decrease delirium incidence (prevention)?

- early mobilization and control of patient's environment (light, noise, stimuli)

- no medications are recommended for prevention

What can be used to treat ICU delirium?

atypical antipsychotics (quetiapine) can be useful

haloperidol has little evidence to support

Precedex generic name

dexmedetomidine

dexmedetomidine drug class

alpha-2 adrenergic agonist

dexmedetomidine side effects

hypo/hypertension, bradycardia

How long is the duration of infusion of dexmedetomidine?

should not exceed 24 hours

dexmedetomidine indication

used for sedation in intubated and non-intubated patients

Igalmi = sublingual film for agitation with schizophrenic/bipolar disorder

Does demedetomidine require refrigeration?

No

Diprivan generic

Propofol

Diprivan contraindication

hypersensitivity to egg, soy

propofol side effects

hypotension

apnea

hypertriglyceridemia

green urine/hair/nail beds

propofol-related infusion syndrome (PRIS) rare

propofol monitoring

triglycerides

Diprivan administration

use strict aseptic technique due to potential for bacterial growth

discard vial and tubing within 12 hours of use

What kind of emulsion is propofol?

oil-in-water

provides 1,1 kcal/mL

How can lorazepam cause propylene glycol toxicity?

the infection formulation is in propylene glycol

total daily dose as low as 1mg/kg/day can cause propylene glycol toxicity (acute renal failure and metabolic acidosis)