Intro to Cardiovascular Pharmacology/Airway Emergencies & Airway Emergent Management

  1. 3 Factors Differentiate ICU From Other Units:
    • A very high nurse to Pt. ratio
    •  Availability of Invasive Monitoring
    •  Use of mech. & pharmacological life sustaining therapies.          (Mech. vent., vasopressors, continuous dialysis.)
  2. Assessment is Ongoing....
    • Verbal communications
    • Written communications
    • Lab results
    • Imaging studies
    • Physical education
    • Monitoring - Trends often more important than "snapshot"
  3. Levels of Evidence Based Medicine:
    • Positive, randomly controlled multicenter trial
    • Neutral, randomly controlled trial
    • Prospective, non-random trial
    • Retrospective study
    • Case study
    • Extrapolation
    • Animal study 
    • Conjecture, common sense
  4. Pharmokinetics:
    Bioavailability
    • Concentration
    • Route of Admin
    • Absorptive Area
    • Drug interactions
    • Dose
    • Rate of dissolution or metabolism
    • GI Motility
  5. Pharmokinetics:
    Volume of Distribution
    • 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)
  6. Pharmokinetics:
    Clearance
    • The rate of elimination from circulation
    • Often through the liver
    • Drug interactions can either accelerate or slow clearance
  7. Pharmokinetics:
    Half-life
    The time needed for concentration to fall 50%
  8. Pharmokinetics:
    Route of Drug Administration
    • Inhalation
    • Intratracheal
    • Intramuscular/Subcutaneous
    • Intracardiac
    • Intravenous/Intra-arterial 
    • -Peripheral 
    • -Central
  9. Pharmokinetics:
    Peripheral Venous Route
    • 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
  10. Pharmokinetics:
    Central Venous Route
    • 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
  11. Pharmokinetics:
    Intratracheal Route
    • 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!!!!


  12. ONLY "A.L.E."

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

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

  13. Pharmokinetics:
    Intracardiac Route
                          **NOT RECOMMENDED!**

    • May produce pneumo, injury to a coronary artery & prolonged interruption of cardiac massage
    • Inadvertent injection into the myocardium may produce intractable arrhythmias
  14. Pharmokinetics:
    Resuscitation & Shock
    • Epinephrine
    • Vasopressin
    • Atropine
    • Buffer Agents
    • Calcium
  15. Indications, Contraindications, Dosages for:
    Epinephrine
    • 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.)
  16. Indications, Contraindications, Dosages for:
    Vasopressin
    • 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
  17. Drugs for Persistent VF:
    • Amiodarone
    • Lidocaine
    • Magnesium sulfate
  18. Drugs for Persistent VF:
    Amiodarone
    • 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
  19. Drugs for Persistent VF:
    Lidocaine
    • 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
  20. Drugs for Persistent VF:
    Magnesium Sulphate
    • Class 2 b intorsades de pointes or suspected hypomagnesaemia or severe refractory VF
    • 1-2g diluted in 100ml D5 over 1-2mins
  21. Indications, Contraindications & Dosages For:
    Atropine
    • 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"
  22. Indications, Contraindications & Dosages For:
    Buffer Agents
    • 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
  23. Indications, Contraindications & Dosages For:
    Buffer Agents Continued...
    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
  24. Indications, Contraindications & Dosages For:
    Calcium
    • 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
  25. Airway Adjuncts
    Supraglottic Airways:

    • Oropharyngeal
    • Nasopharyngeal

    Blind Placement:

    • Laryngeal Mask Airway (LMA)
    • King Airway
    • Combitube
    • Nasotrachael ETT
  26. Intubation Equipment:
    • 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)
  27. Rapid Sequence Intubation (RSI)
    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!)
  28. Rapid Sequence Intubation Indications:
    • 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)
  29. Rapid Sequence Intubation "6 P's"
                 **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"
  30. RSI "6 P's":
    Preparation
    • Evaluate - LEMON
    • Equipment Check
    • Positioning
    • Drug selection
    • IV's, Monitor, Oximetry
    • Ancillary Staff
    • Anticipate alternative airway maneuver
  31. L.E.M.O.N.
    • L = look
    • E = evaluate
    • M = mallampati
    • O = obstruction
    • N = neck mobility
  32. RSI "6 P's":
    Preoxygenation
    100% O2 for 5mins of 5 vital capacity breaths can theoretically permit 3-5 mins of apnea before desaturation to <90% occurs
  33. RSI "6 P's":
    Premedication
    • 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!)**
  34. Premedication in Intubation:
    Lidocaine
    •                               **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
  35. Premedication in Intubation:
    Atropine
                                     **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
  36. Premedication in Intubation:
    Defasciculating Doses
    • ↓ 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
  37. Premedication in Intubation:
    Sedation
    • 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.
  38. Premedication in Intubation:
    Etomidate (Amidate)
         **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)
  39. Premedication in Intubation:
    Propofol (Diprivan)
    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
  40. Premedication in Intubation:
    Ketamine
    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
  41. Premedication in Intubation:
    Fentanyl
    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
  42. Premedication in Intubation:
    Morphine Sulfate
                     **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
  43. Premedication in Intubation:
    Midazolam, Diazepam, Lorazepam
    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
  44. Premedication in Intubation:
    Midazolam
    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
  45. Premedication in Intubation:
    Diazepam & Lorazepam
    • Moderate/long acting agents
    • Longer onset time than midazolam
    • May be more beneficial post-intubation for sedation
  46. Depolarizing Agents:
    Succinylcholine (anectine)

    "succs" agent of choice
  47. Non-Depolarizing Agents:
    Pancuroniam (Pavulon)

    Vecuronium (Norcuron)

    Atracurium (Tracrium)

    Rocuronium (Zemuron)

    Miuacurium (Mivacron)
  48. Chemical paralysis facilitates intubation by allowing...
    Visualization of the vocal cords & optimizing intubating condition

    ONLY CONTRAINDICATION:

    • Anticipated difficult airway
    • Mallampati Class
    • Thyromental Distance
  49. Succinylcholine
    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)
  50. Prolonged paralysis seen w/
    • Pregnancy
    • Liver disease
    • Malignancies
    • Cytotoxic drugs
    • Certain antibiotics
    • Cholinesterase inhibitors
    • Organophosphate poisoning
  51. Adverse reactions in Paralysis:
    • Muscle Fasiculations
    • Hyperkalemia
    • Bradycardia
    • Prolonged neuromuscular blockade
    • Malignant hyperthermia
  52. Adverse Reactions:
    Muscle Fasciculations
    • Thought to ↑ ICP/IOP/IGP
    • Causes muscle pain
    • Minimized by "Priming" dose of NMB
  53. Adverse Reactions:
    Hyperkalemia
    • Average ↑ in Potassium 0.5-1mEq/L
    • Burns, crush injuries, spinal cord injuries, neuromuscular disorders, chronic renal failure
  54. Adverse Reactions:
    Bradycardia
    • Most common in children <10yrs due to higher vagal tone
    • Also w/ repeated doses of succinylcholine
    • Premedicate w/ atropine
  55. Adverse Reactions:
    Malignant Hyperthermia
    • From excessive calcium influx through open channels
    • Genetic predisposition
    • Rapid temperature, rhabdomyolysis, muscle rigidity, D/C
    • 60% mortality
    • Tx: IV Dantrolene
  56. Vecuronium
    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
  57. Rocuronium
                         **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
  58. Placement of Tube:
                    **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
  59. When Bagging....
    • 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
  60. Difficult Airway Techniques:
    • BURP Maneuver
    • Airway Exchange Devices
    • Bronchoscope Guided Airway Management
    • Illuminated Stylet
    • Retrograde Intubation
  61. Difficult Airway Techniques:
    BURP Maneuver
    BURP = Back, UP, Right & Posterior

    A variation on the Sellick's maneuver (cricoid pressure)
  62. Difficult Airway Techniques:
    Airway exchange devices
    • Eschmann
    • Bougie catheters
  63. Difficult Airway Techniques:
    Bronchoscope Guided Airway Management
    • Glidescope
    • Standard bronchoscope
    • ENT bronchoscope
Author
amwallis
ID
354402
Card Set
Intro to Cardiovascular Pharmacology/Airway Emergencies & Airway Emergent Management
Description
Pharmacology/Airway Emergencies/Management
Updated