Intro to Cardiovascular Pharmacology/Airway Emergencies & Airway Emergent Management

• A very high nurse to Pt. ratio
•  Availability of Invasive Monitoring
•  Use of mech. & pharmacological life sustaining therapies.          (Mech. vent., vasopressors, continuous dialysis.)

• Verbal communications
• Written communications
• Lab results
• Imaging studies
• Physical education
• Monitoring - Trends often more important than "snapshot"

• Positive, randomly controlled multicenter trial
• Neutral, randomly controlled trial
• Prospective, non-random trial
• Retrospective study
• Case study
• Extrapolation
• Animal study 
• Conjecture, common sense

• Concentration
• Route of Admin
• Absorptive Area
• Drug interactions
• Dose
• Rate of dissolution or metabolism
• GI Motility

• Total amount of drugs in the body related to its plasma concentration
• Used to determine loading dose
• Can create a "reservoir effect"     
• EX: Propofol (Large dose to load, small dose to maintain, and a slow release of sequestered medication)

• The rate of elimination from circulation
• Often through the liver
• Drug interactions can either accelerate or slow clearance

The time needed for concentration to fall 50%

• Inhalation
• Intratracheal
• Intramuscular/Subcutaneous
• Intracardiac
• Intravenous/Intra-arterial 
• -Peripheral 
• -Central

• Peak effect 1.5-3 mins after injection @ antecubital fossa
• IV Push
• - 20ml NS flush after drug injection
• - ↓ circulation time by 40%
• - comparable to drug delivery through a central vein

• Faster, higher peak concentration & more potent effect compared to peripheral injection
• Should be used if it is already in situ
• Inserting a central line is associated w/ problems of interrupting CPR, bleeding arterial puncture & air embolism

• NOT a 1st choice due to unpredictable pharmacodynamics
• Need 2-3x the IV dose
• Non-ionic drugs ONLY:  Atropine, Lidocaine, Epinephrine
• NEVER CALCIUM OR SODIUM BICARBONATE!!!!

• A = Atropine
• L = Lidocaine
• E = Epinephrine

"Always pour A.L.E down the throat"

                      **NOT RECOMMENDED!**

• May produce pneumo, injury to a coronary artery & prolonged interruption of cardiac massage
• Inadvertent injection into the myocardium may produce intractable arrhythmias

• Epinephrine
• Vasopressin
• Atropine
• Buffer Agents
• Calcium

• 1mg (10ml of 1:10,00 dilution) IV boluses every 3-5 mins until pulse returns
• Short half-life of 3-5mins
• ∞
• -Effect (vasoconstriction)
• - ↑ Aortic pressure to maintain myocardial & cerebral blood flow

CAUTIONS: Solvent abuse, cocaine & other sympathomimetic drugs (meth etc.)

• 40 U IV: Powerful vasoconstriction
• V, receptors in smooth muscle
• Longer half-life of 10-20mins
• IF no response 10-20 mins after 40 U of IV vasopressin, resume epinephrine 1mg IV push every 3-5 mins
• Used in VF/VT
• ? role in asystole or PEA

• Amiodarone
• Lidocaine
• Magnesium sulfate

• Class 2 b
• Rapid infusion of 300mg in 20-30ml NS IV push (cardiac arrest dose)
• IF VF/Pulseless VT recurs...
• -Supplementary doses of 150mg IV by rapid infusion
• -Followed by 1mg/min for 6hrs & then 0.5mg/min
• -Max daily dose of 2g

• Class Indeterminate
• Initial bolus of 1.0-1.5 mg/kg
• Additional bolus of 0.5-0.75 mg/kg
• Max total of 3 mg/kg
• Maintenance infusion of 1-4 mg/min

• Class 2 b intorsades de pointes or suspected hypomagnesaemia or severe refractory VF
• 1-2g diluted in 100ml D5 over 1-2mins

• Good for hemodynamically significant bradycardia from high vagal tone, hypoxia or nodal ischemia
• For asystole or PEA
• 1mg up to 3 doses or single dose of 3mg will produce a fully vagolytic effect
• Vagolytic
• Drys everything up
• Can give low dose inhaled

"1/2 dead = 1/2 dose, FULL dead = FULL dose"

• 8.4% Sodium Bicarbonate solution
• Initial dose of 1mEq/kg

PROBLEMS: 1.Left shift of Hb dissociation curve. 2.Paradoxical intracerebral acidosis. 3.High osmolality & Na load. 4.Inactivate simultaneously admin catecholamines

Indications for NaHCO3:

• Class 1
• -Pre-existing hyperkalemia
• -Pre-existing bicarbonate - responsive acidosis
• -Alkaline diuresis; overdose of tricyclic antidepressant, aspirin, etc.
• Class 3
• -Hypercarbic acidosis
• Class 2b
• Long arrest interval
• -In intubated & vent Pt's
• -On return of circulation

• ONLY use in Hypocalcemia, Hyperkalaemia & Calcium antagonist overdose
• 10% CaCl2 @ 2-4mg/kg repeated as necessary @ 10min intervals
• Worries regarding the role of Ca++ in ischemic cell damage during reperfusion to the heart & the brain

Supraglottic Airways:

• Oropharyngeal
• Nasopharyngeal

Blind Placement:

• Laryngeal Mask Airway (LMA)
• King Airway
• Combitube
• Nasotrachael ETT

• Laryngoscope w/ relevant size blades - (Miller=Straight, Mac=Curved)
• Magill Forceps
• Stylet
• 10-20 ml syringe
• Oropharyngeal airways - (ALL sizes)
• Tape or commercial securing device
• Bag-Valve-Mask w/ O2 connected
• Suction unit w/ Yankauer catheter & endotracheal suction catheter
• ET Tubes - (Relevant Sizes)

The induction of a state of unconsciousness w/ complete neuromuscular paralysis to achieve intubation w/out interposed mech. vent. in efforts to facilitate the procedure & minimize risks of gastric aspiration.

(Meant to get tube in NOW!)

• 1.Failure of airway maintenance/protection →
• (Lost or diminished gag reflex)
• 2.Failure of oxygenation/ventilation →
• (Pulmonary edema, COPD)
• 3.Anticipated clinical course →
• (Multiple trauma, head injured) - (Intoxication, air transport)

             **12 Mins Total**

• Preparation: T-10"  -  Positioning
• Preoxygenation: T-5"
• Premedication: T-3"
• Paralysis: T-0
• Placement of tube: T+45
• Post Management: T+2"

• Evaluate - LEMON
• Equipment Check
• Positioning
• Drug selection
• IV's, Monitor, Oximetry
• Ancillary Staff
• Anticipate alternative airway maneuver

• L = look
• E = evaluate
• M = mallampati
• O = obstruction
• N = neck mobility

100% O2 for 5mins of 5 vital capacity breaths can theoretically permit 3-5 mins of apnea before desaturation to <90% occurs

• Goal is to blunt the Pt's physiologic responses to intubation
• Minimizes bradycardia, hypoxemia cough/gag reflex, ↑ in intracranial, intraocular, & intragastric pressures

**(Always have 2 people who can intubate in the room!)**

•                               **RARE**
• Thought to blunt the rise in intracranial pressure associated w/ airway manipulation & the use of depolarizing neuromuscular blocking agents
• 1.5-3.0 mg/kg (average 100mg) 3mins prior to intubation

                                 **RARE**

• Can minimize vagal effects, bradycardia & dry secretions
• 0.02mg/kg, minimum 0.1mg IV, Max 1mg, 3mins prior to intubation
• Infants & children <8yrs may develop profound bradycardia during intubation

• ↓ muscle fasciculations caused by the depolarizing agents (succinylcholine)
• Attenuates rise in intracranial pressure
• Agents used are the non-depolarizing blocking agents (vecuronium, pancuronium etc.) usually 1/10 of standard dose

• Sedative agents administered @ doses capable of producing unconsciousness w/ little or no cardiovascular effects
• NO ideal agent exists
• Sedation should always be used when paralyzing the Pt.

     **Usually will push this 1st in RSI**

A nonbarbiturate hypnotic:

• ↓ ICP/IOP
• Rapid onset, short duration
• ↑ seizure threshold
• Watch for myoclonus (tensing up), vomiting
• Dose 0.3mg/kg IV
• Minimal hemodynamic effects
• NO histamine release
• NO malignant hyperthermia reported
• May ↓ cortisol synthesis (adrenal insufficiency)

Sedative Hypnotic:

• Extremely rapid onset (10sec), duration of 10-15mins
• Can cause profound hypotension
• Dose: 100-200mcg/kg/min for maintenance
• ↓ ICP
• Dose 1-3mg/kg IV for induction

Dissociative Anesthetic:

• Rapid onset, short duration
• Potent bronchodilator, useful in asthmatics
• "Emergence" phenomenon can occur though rarely in children <10yrs
• ↑ ICP, IOP, IGP
• ↑ bronchial secretions
• Contraindication in head injuries
• Emergence reactions occur in up to 50% of adults
• Dose: 1-2mg/kg

Broad Dose-response Relationship:

• Can be reversed w/ naloxone
• Fentanyl is rapid acting (,1min), duration of 30mins -Does NOT release histamine
• May ↓ tachycardia & hypertension associated w/ intubation
• Seizures & chest wall rigidity have been reported
• Dose: 2-10mcg/kg IV

                 **NOT ideal for airway management**

• May not blunt the rise in ICP, hypertension & tachycardia as well as fentanyl
• Longer onset 3-5 mins & duration 4-6hrs
• Dose: 0.1-0.2 mg/kg IV
• Histamine release

Provide excellent amnesia & sedation

• Broad dose-response relationship
• Reversed w. flumazenil (roma-zicon)
• Dose: required are higher for RSI than for general sedation
• ↑ seizure threshold

Slower onset (3-5) min than the barbiturate/hypnotic agents

• Considered short-acting (30-60min)
• Does not ↑ ICP
• Causes Resp. & Cardiovascular depression
• Dose: 0.1-0.4mg/kg IV

• Moderate/long acting agents
• Longer onset time than midazolam
• May be more beneficial post-intubation for sedation

Succinylcholine (anectine)

"succs" agent of choice

Pancuroniam (Pavulon)

Vecuronium (Norcuron)

Atracurium (Tracrium)

Rocuronium (Zemuron)

Miuacurium (Mivacron)

Visualization of the vocal cords & optimizing intubating condition

ONLY CONTRAINDICATION:

• Anticipated difficult airway
• Mallampati Class
• Thyromental Distance

Stimulates nicotinic/muscarinic cholinergic receptors

• Gold standard for 50yrs
• Onset 45secs, duration 8-10mins
• Dose: Adults = 1.5mg/kg IV & Children = 2.0mg/kg IV
• Inactivated by pseudocholinesterase (body produces this)

• Pregnancy
• Liver disease
• Malignancies
• Cytotoxic drugs
• Certain antibiotics
• Cholinesterase inhibitors
• Organophosphate poisoning

• Muscle Fasiculations
• Hyperkalemia
• Bradycardia
• Prolonged neuromuscular blockade
• Malignant hyperthermia

• Thought to ↑ ICP/IOP/IGP
• Causes muscle pain
• Minimized by "Priming" dose of NMB

• Average ↑ in Potassium 0.5-1mEq/L
• Burns, crush injuries, spinal cord injuries, neuromuscular disorders, chronic renal failure

• Most common in children <10yrs due to higher vagal tone
• Also w/ repeated doses of succinylcholine
• Premedicate w/ atropine

• From excessive calcium influx through open channels
• Genetic predisposition
• Rapid temperature, rhabdomyolysis, muscle rigidity, D/C
• 60% mortality
• Tx: IV Dantrolene

Duration of 30-60min, onset of 1-4min

• Hypotension may occur from loss of venous return & sympathetic blockade
• Most biliary excertion
• "Priming dose" 0.01mg/kg
• Dose: 0.1mg/kg

                     **Very versatile drug**

Duration 30-45min, has the shortest onset of the non-depolarizing agents (1-3min)

• Tachycardia can occur
• Dose: 0.6-1.2mg/kg

                **Allow meds to work!!**                

• & assure complete neuromuscular blockade of the Pt.
• Maintain Sellick maneuver until cuff inflated
• Ventilate w/ bag-valve-mask if unsuccessful
• Additional doses of sedatives/NMB may be necessary
• Confirm tube placement

• FiO2 of 1.0
• Manual resuscitators or vents
•   x 12-15bpm
•   x Vt
•       ~ 10-12 ml/kg, IF intubated
•       ~ 6-7 ml/kg, IF not intubated

• BURP Maneuver
• Airway Exchange Devices
• Bronchoscope Guided Airway Management
• Illuminated Stylet
• Retrograde Intubation

BURP = Back, UP, Right & Posterior

A variation on the Sellick's maneuver (cricoid pressure)

• Eschmann
• Bougie catheters

• Glidescope
• Standard bronchoscope
• ENT bronchoscope