Asthma Flashcards
Definition of asthma
Chronic inflammatory disorder with increased responsiveness of airways to stimuli
Reduction in airway diameter from smooth muscle contraction, vascular congestion, bronchial wall edema and thick secretions
3s of asthma
Swelling, secretion, spasm
Extrinsic asthma
Allergic, type I hypersensitivity from environmental allergens
Intrinsic
Non-allergenic
Believed to be from excess Ach
Exercised induced bronchospasm
Triggers
Allergens, irritants, cold, high humidity, infections, physical exertion, excitement/emotional stress ASA, NSAIDs, betablockers
Airway signs
One-two word sentences
Tachypnea, increased WOB, accessory muscle use, cyanotic, cough, stridor
Wheezes
May not always be present Mild-moderate only expiratory Moderate - loud and both phases Severe - loud or decreased Silent chest - oh shit!
Milk
Expiratory wheezes
Full sentences, may be agitated, tachpnea, not using accessory muscles, HR under 100 SP02 95
Moderate
Breathless at rest, prefers to sit, phrases, agitated, increase RR, accessory muscles, HR 100-120, pulsus paradoxus possible O2 90-95%
Severe
Resps over 30, HR >120 sats under 90
Imminent resp arrest
Drowsy, confusion, paradoxical thoracoabdominal movement, silent ches, bradycardia usually beta agonists don’t work
ASTHMATIC differential
Asthma Stasis (pulmonary edema) Toxic (gas, smoke, poison) Heart (CHF, ARDS, cardiac asthma) Mechanical (FBAO) Allergy/aspiration Trauma/tumor Infection COPD, cystic fibrosis
Tubing
Risk of barotraumas and pneumothorax, can further bronchoconstriction and breath stacking (auto peep)
Auto-peep
Inspiration is greater than expiration, intrathoracic pressure increases and decreases CO
Risk of tension pneumo
Slower resp rate 6-10 min, smaller tidal volumes (6-10mL/kg) short inspiratory time and longer expiratory 1:4 or 1:5
Ventolin
Stimulates sympatho receptors in resp tree causing bronchodilation
Atrovent
Reverses only cholinergic mediated bronhospasm, blocks bronchoial constriction, inhibits mucus, can take up to 60 mins works in 30 seconds, 50% at 30 minutes persists for 6 hours
Corticosteroids
Reverse inflamm, speeds recovery, reduces rate of relapse, 4-6 hours for clinical effect Dex 8mg IV IM IO Pred 50 mg PO Methylprednisolone 125mg IV/IO No repeats
Epi pros and cons
B2 bronchodilation
B1 increased O2 demandes
0.3mg 1:1000 IM max 0.9mg
Status asthma
Failed to respond to continuous aggressive tx after 4 hours
Turns to refractory status asthma
progresses to PEA, be very aware of barotrauma
same ACLS drugs
Poison control #
1 800 332 1414
Questions
bring pills to hospital
What, how much, when, txs, vomited, suicide attempt, underlying illness?
Reduction of absorption
Ipecac (rarely used)
Gastric lavage
Activated charcoal
Enhance elimination
Cathartics (laxative)
Whole bowel irrigation
Surface absorbed
Organophosphates, cyanide, household chemicals, poison ivy, poison oak
Antichols
antihistamines, antipsychotics, antidepresssants, antiparkinsonian
S&S antichol
Red as a beet Dry as a bone Blind as a bat Mad as a hatter Hot as a hare Flushing, dry skin and membranes, mydriasis (dilation), fever, altered LOC, tachycardia
Common TCAs
Amitriptyline (elavil)
Amoxapine (asendin)
Clomipramine (anafranil)
Doxepin (sinequan)
4 main pharmo properties of TCAs
Inhibit Norepi, serotonin reuptake
Antichols
Direct alpha-adrenergic block
Inhibits K+ channels in myocardium and Na+ in brain and myocardium
Common TCA S&S
Delerium, coma, seziures, resp depression, sinus tach, long PRI QRS and QT, heart blocks, hypotension, ventricular arrhythmias, blurred vision, mydriasis
TCA management
ABCs
BGL, IVs
Heart blocks, long PRI, wide QRS,
Brugada pattern (incomplete RBBB with ST elevation V1, V3)
bradycardia, ventricular dysrhythms including PMVT
Wide QRS key for tx w/ bicarb
TX TCA
no more than 40mL/kg
Bicarb 1-2mEq/kg for refract hypotension and initial seizure
Seizures tx with benzos (remember check monitor for dysrhythmia that looks like a seizure)
Torsades 2g mag in 50mL over 5
GCS less than 8 consider advanced airway as it predicts cardiotoxicity and or seizures
Pressors for refract hypotension, nor epi if not then epi
Drugs for TCA
Bicarb, benzos, mag, pressors, intubation
Activated charcoal
Not effective for Cyanide Mineral acids Caustic alkalis Ethanol Methanol Organic solvents NG/OG or orally
Contras in activated charcoal
Corrosive agent or petroleum distillate (may cause vomiting)
Dose 1gm/kg PO NG, OG same for peds
Cholinergic toxicity
Cholinesterase inhibitors prevent ACh from reuptake. Similar effects as organophosphate, S&S depend on if its muscarinic or nicotinic
S&S of chol tox
Miosis (constricted)/dim vision
Tight chest
Muscular weakness, cramps diarrhea, breathing difficulty and convulsions
BMSLUDGE
Bradycardia/bronchospasm Miosis (constrict) Salivation/sweating Lacrimation Urination Defication GI upset Emesis
Organophopshates
Acephate (orthene) Chlorphoxim (baythion-C) Chlorpyifos (dursban, lorsban) Diazinon Dimethoate (cygon, defend) Ethoprop (mocap) Fenitrothion (sumithion) Fenthion (baytex) Malathion (cythion) Naled (Dibrome) Terbufos (counter)
TX
Decontaminate, assist ventilations, monitor for tordsades,
atropine 2-4mg q 1-5, watch for non cardiogenic pulmonary edema, avoid succ’s/prolonged paralysis
AHS atropine dose
2mg q 5 until reversal of symptoms
Pralidoxime Hydrochloride (2-PAM)
Antidote only for organophosphate. Binds to site different than organophosphate and boots it off. Must be given early
Sympatho OD
Intracranial hemorrhage possible from HTN
Aortic dissection possible
Sodium channel blockade with some
Benzos, fluid, maybe beta blockers, maybe bicarb, and ice to groin, neck, axilla
Unopposed alpha receptor stim
Thought to be because beta block blocks beta 2 (peripheral vasodilation) but A1 is still hit.
LITFL says minor increase in BP, minor drop in heart rate, safe to give
Bicarb for stims
Cocaine blocks sodium channels like TCA. Tx wide QRS with bicarb
Narcan dose
0.4mg q 2 max 1.6
0.8mg q 5 max 3.2
2mg intranasal (1mg/nare) q3-5 max 4mg
Peds narcan
IV or IM 0.1mg/kg max 2mg single dose, max total 10mg (same for intranasal but max 2mg)
Anxiolytic OD (Benzos, barbs) presentation
Decreased LOC, delirium, slurred speech, combative, coma, resp depression, apnea, hypotension, bradycardia, diaphoresis, hypothermia, nystagmus
Benzo reversal
Flumazenil, selective competitive GABA receptor antagonist
Barbs drug tx
Bicarb. Alkalization of urine enhances elimnation of phenobarb and other long acting barbs via ion trapping.
Salicylate OD
protip, oil of wintergreen is high in salicylates
Elimination mostly hepatic but renal excretion becomes important
Salicylate acute/chronic toxicity
Acute is around 150mg/kg
More commonly chronic, vague symptoms and insidious onset. Commonly in oldies as they can’t excrete as much as they take in
Diagnosis on presence of salicylate ingestion + mixed metabolic anion gap acidosis and no other explanation
S&S of salicylate toxicity
Hyperventilation as they directly stimulate resp center, resp alkalosis may be first sign. Increased resps means fluid lossess
Metabolic acidosis from compensation of resp alkalosis and impaired glucose metabolism
As acidosis builds, more drug moved intracellulary, toxicity worsens
Anion gap positive acidosis
S&S salicylates continued
Cerebral and pulmonary edema, poorly understood why, possibly increased cap perm
Hypovolemia and hypokalemia from large amounts of fluid losses (vomiting, diarrhea)
Tachycardia, arrhythmias
Hypoglycemia
May need tubing
Tinnitus
Salicylate tx
Fluid, control hyperthermia, tx hypoglycemia, benzos if seizing, bicarb considered.
Activated charcoal if ingestion has been within 60 minutes
Acetaminophen pathology
Rapidly absorbed, peaks at 2 hours, steady state at 4 hours
Metabolized CYP3A4 and 2E1 into NAPQI (n-acetyl-p-benzoquinonimine) which is highly toxic
Glutathione in liver normally deactivates it, OD uses up all the glutathione
Acetaminophen S&S
N/V Diaphoresis pallor lethargy malaise RUQ pain liver enlargement hypoglycemia
Elevated AST, ALT, bilirubin
TX
ABCs, BGL N-acetylcysteine, hepatoxicity risk at 8 hours post ingestion typically
NAC mechanism
Replenishes stores of glutathione
NAC dose adults
150mg/kg in 200mL of D5 over 15-60 minutes
Then 50ml/kg in 500mL of D5 over 4 hours
Then 100mg/kg in 1000mL over 16 hours
Acetaminophen toxic dose starting point
7000mg single ingestion, 150mg/kg (wiki says 10000 and 200mg/kg)
Beta blocker OD, propranolol
Propranolol most common, its non selective and has membrane-stabilizing effects responsible for CNS depression, seizures, prolonged QRS (sodium channel blockade)
Beta blocker OD physiology
Blocks 1 - reduced hrt rate, BP, myocardial contractility and MVO2
Blocks 2 - inhibits relaxation of smooth muscle in vessels, bronchi and GI system and genitourinary
Also inhibits glycogenolysis and gluconeogenesis which may result in hypoglycemia
Beta blockers S&S
Heart blocks, bradycardia, conduction delays, bronchospasm (if underlying airway disease) decreased LOC (lipid soluble ones like propranolol and acebutolol)
Beta blockers tx
Glucagon increases cAMP, often will cause nausea and vomiting consider prophylatic ondanstron
Insulin increases CO also through non-alpa and non-beta receptor methods
CaCl regulates action potential excitation threshold 8-16mg/kg (100-1000gm)
AHS betablocker/CCB protocol
Tx with heart block protocol Tx hypoglycemia 20mL/kg IV/IO map 65 max 40mL/kg Glucagon 2mg SIVP q 10 max of 6mg Zofran 4mg Calcium chloride for refractory hypotension, 1g SIVP q 10 max 3g Wide QRS bicarb 1mEq/kg q 5 max 2 mEq/kg STILL hypotensive, OLMC for norepi 0.1mcg/kg/min titrate to effect 0.3mcg/kg/min max
Calcium channel names
Verpamil, Isoptin, Nifedipine, Adalat, Diltziazem
4 cardiovascular effects of calcium channel blockers
Peripheral vasodilation Negative chronotropy (rate) Negative intotropy (contractility) Negative dromotropy (conduction)
S&S CCB OD
Decreased LOC, hypotension, bradycardia, various degrees of heart block, seizures, hyperglycemia
CCB OD TX
Calcium chloride - overwhelms CCB Insulin - increased CO ithout A/B receptors TCP (brady cardia with SBP under 90) Glucagon Pressors
Procedural sedation
For pacing too
0.05mg/kg max 2.5mg versed +
1mcg/kg fentanyl max 100
0.5mg/kg ketamine instead if SBP under 100 (consider half dose if pt over 65)
S&S dig tox (usually chronic)
Tachyarrythmias + heart blocks Head, irritability, psychosis Yellow-green vision Anorexia, N/V Palpitations, syncope, dyspnea Atrial tach with block, junctional tach, ectopy
Dig OD patho
Inhibition of Na+/K+ ATPase pump which raises intracellular Ca2+ and Na+ plus loss of K+ which increases force of myocardial contraction (inotropic effect)
Dig also increases automaticity of purkinje but slows AV conduction
Dig TX
Fluid
Atropine/TCP bradycardia
No calcium for hyperK (relative contra, give digibind first)
Digibind (digoxin immunie fab) 400mg IV over 15 minutes
800mg RIVP if cardiac arrest
Ethylene glycol
In antifreeze, small amounts can lead to severe tox, kids sometimes drink as its sweet and fluorescent
Methanol
Windshield washer fluid, small amounts can lead to tox
Ethylene glycol and methanol
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