ICCM - Quiz 3

what is the acid-base equilibrium equation?

CO2 + H2O ⇌ H2CO3 ⇌ HCO3− + H+

what is a complication of respiratory acidosis?

ventricular fibrillation -> death

what is the normal range for blood pH?

7.35 - 7.45

what is the normal range for CO2 on ABG?

35 - 45

what is the normal range for HCO3 on ABG?

22 - 26

what population is at risk for respiratory acidosis?

COPD patients

what are the causes of respiratory acidosis?

lung - COPD, asthma, pneumonia, CHF, hypoventilation

rib - flail chest

muscle - dystrophy

brain - myasthia gravis, botulism, ALS, polio, guillain barre, multiple sclerosis, tumor

acute vs chronic presentation for respiratory acidosis

acute - for every 10 mmHg above 40 for PCO2, the pH will go down 0.08

chronic - for every 10 mmHg above 40 for PCO2, the pH with go down 0.04

acute on chronic - somewhere in between these values

what does ROME stand for?

R - respiratory

O - opposite

M - metabolic

E - equal

partial vs complete compensation

partial - pH is still out of range

complete - pH is back to normal range, but borderline abnormal still

what are causes of respiratory alkalosis?

anxiety/nervousness, hyperventilation, fever, pain, ASA overdose

what are causes of metabolic acidosis due to too much H+?

lactic acid - sepsis, shock, hypoxia

citric acid - citrus fruit

keto acid - DKA, starvation, alcohol

exogenous source - aspirin, methanol, ethylene glycol

distal nephron - polycystic kidney disease

what are causes of metabolic acidosis due to not enough HCO3?

proximal nephron - lupus, sarcoidosis, rheumatoid arthritis

GI - diarrhea

what are causes of metabolic alkalosis due to not enough H+?

vomiting, loop diuretics, sustained hypokalemia

what are the causes of metabolic alkalosis due to too much HCO3?

exogenous - tums (calcium carbonate), baking soda

what percent of oxygen is normal air?

21%

what is the max for nasal cannula?

6 liters

what is the max for venti-mask?

up to 50% oxygen

what is the max for a non-rebreather?

15 liters

what are the options for supplemental oxygen and airway management?

1. nasal cannula

2. venti-mask

3. non-rebreather

4. CPAP

5. BiPAP

6. intubation

how much does 1 liter of oxygen increase the inspired oxygen concentration by?

1 L with raise it 3% (from 21% to 24%)

then every liter after that is 4% (ex. 2L - 28%, 3L - 32%, etc.)

how much pressure is needed to keep normal lung inflated?

5 - 6 liters of pressure

what is CPAP and what is a setting for a healthy person?

continuous positive airway pressure

6 cm H2O

what is CPAP commonly use for?

sleep apnea

what is BiPAP and what is a setting for a healthy person?

bilevel positive airway pressure

similar to CPAP but there are two levels of pressure given

8 / 4 cm H2O - top number is inhalation, bottom is exhalation

what are medications used for rapid sequence intubation (RSI)?

sedative - etomidate, ketamine, or propofol

paralytic - succinylcholine (fastest, but don't use with hyperkalemia), rocuronium, or vecuronium

what are the components to ventilation settings?

tidal volume - the amount of air that moves in and out of the lungs with each normal breath

respiratory rate

FIO2 - fraction of inspired oxygen

positive end-expiratory pressure (PEEP) - the pressure remaining in the lungs at the end of exhalation, above atmospheric pressure, used to keep alveoli from collapsing (normal 5)

what is the history of cephalosporins?

discovered starting in 1945 when Italian scientist Giuseppe Brotzu found a Cephalosporium acremonium fungus

what is the mechanism of action for cephalosporins?

inhibit bacterial cell wall synthesis

what are the side effects for cephalosporins?

local irritation with IV or IM, nausea and diarrhea with oral intake, renal toxicity (uncommon), and cross-reactivity

first generation cephalosporins

cephalexin (PO), cefazolin (IV)

gram + (staph and strep), some gram - coverage

second generation cephalosporins

cefuroxime (PO), cefoxitin (IV), cefotetan (IV or IM)

gram + (staph and strep), some gram - coverage

third generation cephalosporins

ceftriaxone (IV or IM), cefpodoxime (PO), ceftazidime (IV)

broad gram - (ceftazidime covers pseudomonas), some gram + coverage

fourth generation cephalosporins

cefepime (IV)

broad gram - (including pseudomonas), some gram + coverage

fifth generation cephalosporins

ceftaroline (IV)

broad gram -, some gram + coverage (including MRSA)

what is the history of macrolides?

isolated in 1950 from the bacterium Saccharopolyspora erythraea. it was first used clinically in 1952, often as a penicillin alternative for patients with allergies

what is the mechanism of action for macrolides?

bind reversibly to the 50S subunit of the bacterial ribosome inhibiting protein synthesis

what are the macrolide medication names?

erythromycin

azithromycin - shortest half-life

clarithromycin

what is the coverage for macrolides?

gram +, gram -, atypicals

what are the side effects of macrolides?

diarrhea

additionally - cardiac toxicity, ototoxicity and tinnitus

what are the four types of shock?

hypovolemic

cardiogenic

distributive

obstructive

what is shock?

body isn't getting enough blood flow and oxygen to its tissues and organs due to low blood pressure

what organs are impacted by shock?

kidneys (first)

lungs

heart

brain

liver (last)

what is the blood pressure equation?

blood pressure = cardiac output (CO) × systemic vascular resistance (SVR)

what is the equation for cardiac output?

cardiac output = stroke volume (SV) × heart rate (HR)

what is hypovolemic shock and how does the body respond?

what? - not enough blood to pump

equation - decreased stroke volume, increased heart rate, increased systemic vascular resistance

what can cause hypovolemic shock?

blood - trauma, GI (peptic ulcers, diverticula), postpartum bleeding (uterine atony)

non-blood - dehydration, polyuria, burns

what is cardiogenic shock and how does the body respond?

what? - heart is unable to pump enough blood to meet the body's needs

equation - decreased stroke volume, decreased heart rate, increased systemic vascular resistance

what can cause cardiogenic shock?

MI, CHF, arrhythmias, myocarditis, valve disease

what is distributive shock and how does the body respond?

what? - widespread decrease in blood vessel tone and blood flow, leading to inadequate tissue perfusion

equation:

septic and anaphylactic - increased stroke volume, increased heart rate, decreased systemic vascular resistance

neurogenic - decreased stroke volume, heart rate, and systemic vascular resistance

what can cause distributive shock?

sepsis

anaphylaxis

neurogenic

more on septic shock

due to gram - (release endotoxin) or gram + (release exotoxin)

these toxins damage the cells causing release of histamine, prostaglandin, and leukotrienes. they then lyse and cause leaky vessels

more on anaphylactic shock

pathway: peanut -> B cell releasing IgE -> mast cells releasing histamine, prostaglandin, and leukotrienes -> cells lyse and cause leaky vessels

more on neurogenic shock

due to a brain or spinal cord injury - the body is wanting to raise the blood pressure, but brain is unable send the signals

what is obstructive shock and how does the body respond?

what? - heart and vessels are fine, but obstruction is present

equation - decreased cardiac output, decreased heart rate, increased systemic vascular resistance

what are the causes of obstructive shock?

pleural effusion, tension pneumothorax, cardiac tamponade

dental infections

outpatient - augmentin or clindamycin

inpatient - vancomycin and zosyn

lung infections

outpatient pneumonia - levofloxacin, augmentin, azithromycin, or doxycycline

inpatient pneumonia - ceftriaxone and azithromycin or levofloxacin

derm infections

cat/dog bite - augmentin or clindamycin

simple cellulitis - cephalexin

large cellulitis (MRSA) - doxycycline, bactrim, or clindamycin

GI infections

diverticulitis (E.coli, bacteroides) - ciprofloxacin and metronidazole

outpatient colitis - ciprofloxacin and metronidazole

inpatient colitis - zosyn

GU infections

outpatient UTI - ciprofloxacin, bactrim, augmentin, cephalexin, levofloxacin, doxycycline, clindamycin, macrobid

inpatient UTI - ceftriaxone

ESBL UTI - carbapenem

what is the history of clindamycin?

first made in 1966 from lincomycin

what is the mechanism of action of clindamycin?

bind reversibly to the 50S subunit of the bacterial ribosome inhibiting protein synthesis

what is the coverage of clindamycin?

gram + (MRSA), gram -, anaerobes

what are the side effects of clindamycin?

diarrhea (risk of C. diff superinfection), skin rash

what is the history of bactrim?

discovered in 1968

combined two antibiotics, sulfamethoxazole and trimethoprim, to create a more potent drug

what is the mechanism of action of bactrim?

inhibit dihydropteroate synthase, blocking folate synthesis

what is the coverage of bactrim?

gram + (MRSA), gram -

what are the side effects of bactrim?

stevens-johnson syndrome, nausea, vomiting, diarrhea, crystalluria, dermatologic hypersensitivity (sulfa allergy)

what is the treatment for SJS

send patient to burn unit and IVIG

what is the ethical principle of autonomy in medicine?

respecting the right of an individual to be self-directing and to make decisions freely and independently about their own body

what is the ethical principle of beneficence in medicine?

acting in the best interest of patients and promoting their well-being

what is the ethical principle of nonmaleficence in medicine?

above all else, do no harm

what is the ethical principle of justice?

to treat all persons fairly and equitably, treating similar cases in the same manner

what is an advance directive?

a legal document that outlines a patient's healthcare wishes, to be invoked if the patient loses decision-making capacity

what is a healthcare power of attorney?

a specific type of advance directive that grants an appointed person the authority to make medical decisions on behalf of an incapacitated patient

patient must have capacity to make medical decisions in order to sign

what are the advanced care planning goals?

maintaining sense of control

relieving the burden

strengthening relationships

respecting culture

in Ohio, what is the legal hierarchy for medical decision-makers if the patient has no medical power of attorney?

spouse

majority of adult children

majority of adult siblings

what procedure must be followed in Ohio to provide medical procedures for a patient who lacks decision-making capacity and has no POA or next of kin?

two physicians must consent for each medical procedure

full code

patient wants full resuscitation including chest compressions, defibrillator shocks, intubation and mechanical ventilation

DNR-CCA

full medical treatment including intubation, vasopressors, synchronized cardioversion for unstable arrhythmias WITH A PULSE and other aggressive therapies UNTIL to point of cardiac arrest

if the patient's heart stops, no further resuscitation is initiated

DNR-DNI

patient wants full medical treatment including vasopressors, oxygen support, and cardioversion for unstable arrhythmias WITH A PULSE and other aggressive therapies EXCEPT intubation

if the patient's heart stops, no further resuscitation is initiated

non-invasive mechanical ventilation would be an option for this patient depending on rapid reversibility of underlying process

if this patient develops respiratory distress or failure, discussions regarding palliative medicine or hospice should be initiated

DNR/CC

only comfort measures will be used, no further diagnostic measures or life sustaining therapies

what is the definition of palliative care?

specialized medical care for people with a serious illness, focused on providing relief from symptoms and stress to improve quality of life

can a patient receive aggressive, curative medical therapy while also receiving palliative care?

yes, palliative medicine can be provided concurrently with aggressive medical therapy

what is the definition of hospice care?

medical care for people with an anticipated life expectancy of 6 months or less, where the focus shifts from cure to symptom management

what is the difference between home hospice and inpatient hospice?

home hospice involves intermittent nurse visits, while inpatient hospice is for patients with more significant symptoms or who lack 24/7 care at home

before compassionately extubating a patient, what two classes of medications MUST be discontinued?

propofol and paralytics

what are the two main classes of medications used for comfort care in end-of-life?

Opiates (Morphine, Fentanyl, Oxycodone)

Anxiolytics (Lorazepam, Midazolam)

why is Morphine not an ideal opiate for comfort care in a patient with renal failure?

its metabolites can accumulate in patients with renal failure, causing neurotoxicity

what must be done with an implantable cardioverter-defibrillator (ICD) before transitioning a patient to comfort care?

it must be ensured that the defibrillator function is discontinued or deactivated

what are the stages of grief?

denial - refuses to accept the reality of a situation

anger - accepts the reality, but now direct anger toward oneself, family, God, etc

bargaining - attempts to negotiate or make compromises

depression - feeling of sadness and hopelessness

acceptance - coming to terms with accepting the reality of our loss

what is prolonged grief disorder?

a diagnosable medical condition where feelings of acute grief persist and cause significant impairment and distress for more than a year