Transcript Als pharmacology

ALS PHARMACOLOGY:
INTRAVENOUS FLUIDS &
DRUG CALCULATIONS
Amy Gutman MD
EMS Medical Director
[email protected]
www.teaems.com
OVERVIEW
 Review of fluids &
electrolytes
 Techniques of intravenous
& intraosseous infusions
 Mathematical principles
used in pharmacology & to
calculate medication doses
 Medication administration
routes
DISCLAIMERS
 #1
 I am a woman
 I am bad at math
 Do not extrapolate ALL
women are bad at math
 #2
 This is a boring lecture
 This is a necessary
lecture
 Do not extrapolate ALL
my lectures are boring
MEDICATION ADMINISTRATION ROUTES
Discussed Today
 Intravenous (IV)
 Intraosseous (IO)
Other Routes
 Sublingual (SL)
 Subcutaneous (SQ)
 Parenteral (PO)
 Rectal (PR)
 Inhalation (IH)
 Endotracheal (ET)
 Transdermal (TD)
 Intramuscular (IM)
 Intranasal (IN)
NATIONAL EMS EDUCATION STANDARD
COMPETENCIES ~ PHARMACOLOGY
 Provider integrates pharmacology knowledge to formulate a
treatment plan intended to mitigate emergencies & improve
the overall health of patient
 Administer medications within scope of practice
 Understand “six rights” of medication administration
 Understand advantages, disadvantages & techniques for
establishing venous access
 Review math concepts, including dose & rate calculations
 Describe role of medical direction
MEDICAL DIRECTION
 Medication administration governed by local protocols & /or
online medical direction
 Standing Orders:
 Off-line or indirect medical control of predefined procedures
 Online (Direct) Medical Control:
 Must contact physician prior to performing certain procedures
 When in doubt, contact medical control
 When an order is given, if unclear / inappropriate, ask MD to repeat
 Repeat back to confirm name, dose & route of delivery
VASCULAR ACCESS
 In ill or injured patients,
survival may depend on
ability to obtain access for
fluid & drug resuscitation
 Peripheral extremity
 Eternal jugular vein
 Intraosseous
 Harm can result from
improper technique or
insufficient pharmacology
knowledge
“RIGHTS” OF MED ADMINISTRATION
 Right patient
 Right drug
 Right dose
 Right route
 Right time
 Right documentation
MEDICATION ADMINISTRATION
 Know prior to administration
 Mechanism of action
 Indications
 Contraindications
 Side effects
 Routes of administration
 Pediatric & adult doses
 Dose calculations
 Antidotes / reversal agents
DOCUMENTATION
 Name of drug
 Dose of drug
 Time administered
 Administration route
 Person administering drug
 Pt’s response to drug
DRUG CHECKS & LOGS
 At beginning of each shift, check drugs, supplies & equipment
 Not expired / damaged
 Readily available in required quantities
 Paramedic responsible for documentation & security of all
controlled substances
 State, regional & local distribution, security, exchanges &
accountability policies
 Double lock system in each vehicle & base storage
 Drug log kept for at least 3 years
 MD DEA number used to order narcotics
UNIVERSAL PRECAUTIONS
 Treat all BBF as infectious
 I don’t shake pt’s hands
without gloves (especially
kids)
 PPE, gloves & eyewear
 Include full facial protection if
possible splatter
 CDC: hand-washing most
effective method to
prevent disease spread
ASEPSIS
 Routine & thorough hand -washing
 Hand-sanitizer before & after pt
contacts if no access to soap / water
 Disinfect equipment between each
patient & every shift
 Antiseptic prior to invasive
procedures
 Check linen, equipment & supplies
prior to use for intactness,
cleanliness
CONTAMINATED MATERIALS CLEANING
OR DISPOSAL
 After needle penetrates
skin, its contaminated
 After needle unsheathed, its
a weapon
 Immediately dispose of
sharps in a puncture-proof
container
 Follow agency protocol for
disposal of infectious waste
& cleaning of contaminated
equipment
BASIC PHARMACOLOGY KNOWLEDGE
 Specific protocol
 Specifics to that medication or IVF:
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Indications / Contraindications
Therapeutic effects
Side effects
Appropriate dose & re-dosage
Need (+/-) for medical control
 Allergies:
 Known by patient
 Reliable source if not from patient
 Medic-alert jewelry or tags
QUESTIONS?
INTRAVENOUS FLUIDS
CHOOSING APPROPRIATE IVF
 Based upon presenting
& underlying illness or
injury
 Even a small amount of
the poorly chosen fluid
may be harmful
 Most agencies have
limited choices – easy
to familiarize yourself
with specifics of each
BODY COMPARTMENTS
CRYSTALLOIDS
 Commonly used prehospitally
 Normal saline, lactated ringers,
dextrose & saline or water
 Made of water & electrolyte
solutions that easily cross a semi permeable membrane
 Rapidly alter intravascular fluid
levels
 Non-oxygen carrying
 Given as a constant rate or bolus
 Adult: 250cc
 Pediatric: 20cc/kg
 In trauma, consider permissive
hypotension
IV FLUIDS: HYPOTONIC
(HYPO-OSMOLAR)
 0.45% Normal Saline
 Dilutes serum by pulling water
from intravascular space to
interstitial space
 Used for (i.e.) severe dehydration but with significant side
ef fects if given too fast or in large quantities
Hyponatremia if plasma sodium normal
Cells rupture from increased osmotic pressure
Cerebral edema & central pontine demyelinosis
Fluid shift from intravascular to intracellular space causes
cardiovascular collapse
 Third spacing ~ abnormal shift into serum if not enough protein to
“hold” fluid in vascular space
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IV FLUIDS: HYPERTONIC
(HYPER-OSMOLAR)
 1 .8% - 10% saline, mannitol
 Pulls fluid & electrolytes from
intracellular to extracellular compartment
 Large volumes cause hypernatremia & severe dehydration
 Cells collapse from increased extracellular osmotic pressure
 A little goes a long way to increase BP & reduce cerebral
edema
IV FLUIDS: ISOTONIC
(ISO-OSMOLAR)
 0.9% Normal Saline
 Principal resuscitation fluid
 Contains sodium, potassium, chloride in almost same
concentrations as “body water” or “plasma”
 Plasma so stays almost entirely in the extracellular space
 3-1 replacement rule: 3cc isotonic sol’n replaces 1 mL blood
 Why?
IV THERAPY: COLLOIDS
 Albumin, blood, dextran, hetastarch
 Contain particles which do not readily
cross semi-permeable membranes
 Volume stays almost within
intravascular space for prolonged
time compared to crystalloids
 Because of gelatinous properties cause platelet
dysfunction interfering with fibrinolysis & coagulation
factors (factor VIII)
 Can cause significant coagulopathy in large volumes
HBOC HEMOGLOBIN-BASED OXYGENCARRYING SOLUTIONS (HBOC)
 Blood contains hemoglobin which
carries oxygen to cells
 Impractical for prehospital unless
specialized critical care transport
 Refrigeration & unique storage
 “Non-cross matched blood”, or “type O”
expensive, rare, with potential
complications
 Synthetic blood available, rarely
used outside trauma institutions
or military
 PolyHeme, HemoPure
QUESTIONS?
CHOOSING THE RIGHT SITE:
ANATOMY & TECHNIQUES
CHOOSING AN IV CATHETER
 Based on purpose, pt age, location
 Over-the-needle catheters preferred
in prehospital setting
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Readily secured
Minimally cumbersome
Allow some pt movement
No need to immobilize entire limb
 Sized by diameter (gauge)
 Smaller gauge = larger diameter
 Choose largest-diameter catheter for
chosen vein
 Safety needles retract after insertion
EQUIPMENT NEEDED
 PPE (including eye
protection)
 Tape & bio-occlusive
dressing
 Tourniquet
 Alcohol, betadine,
chlorhexadine
 Arm board
 Sharps container
EQUIPMENT NEEDED
 IV solution
 Medical: NS
 Trauma: LR, NS
 Medication drip: NS, D5W
 Administration set w/ extension tubing
 Macro drip (10-15 gtts/cc) for volume
 Micro drip (60 gtts/cc) for medications
 Catheter
 >12 yo + fluid resuscitation: 16-18g, IO
 <12 yo +/- fluid resuscitation: 20-24g, IO
 <6 yo: 20-24g, IO
IV SOLUTION CONTAINERS
 Clear plastic bags
 Labeling:
 Fluid type
 Expiration date
 Do not use after
expiration date, appears
cloudy, discolored, with
visible particulate, or
packaging damaged
INTRAVENOUS CANNULAS
Over-The-Needle
Hollow-Needle
IV ADMINISTRATION
SETS
 Macrodrip
 10 gtts = 1 mL, for large
amounts of fluid
 Microdrip
 60 gtts = 1 mL, for
restricted amounts of fluid
 Measured volume &
secondary infusion sets
 Blood tubing
 Filter prevent clots from
entering body
BLOOD TRANSFUSIONS
 Blood type identified by obtaining
blood type & cross-match
 Uncrossed matched blood is “O”, still requires a blood band which
identifies blood type & product hanging
 Blood must be checked against bracelet & verified by medic even if
already checked by nursing
 Blood administered through specific tubing supplied by hospital
 Assess vitals q15 mins & monitor for hemolytic reactions
 Tachycardia, hives, respiratory distress, CP
PERIPHERAL ACCESS
CHANGING INTRAVENOUS BAG OR BOTTLE
 Prepare new bag / bottle
 Occlude flow from depleted
bag or bottle
 Remove spike from depleted
bag & insert into new bag
 Open clamp to & titrate to
appropriate flow rate
FACTORS AFFECTING IV FLOW RATES
 Thick fluids (colloids) infuse slowly
 Cold fluids run slower than warm fluids
 Height of IV bag must overcome gravity if not a pressure bag
 The larger the diameter, the faster fluid can be delivered
 Check for constricting band, BP cuf f
 Evaluate for infiltration or trauma proximal to IV site
GERIATRIC CONSIDERATIONS
 Puncturing vein may cause
massive hematomas
 Tape may damage skin
 Use smaller catheters (20,
22, 24 g)
 Cardiovascularly sensitive
to rapid fluid shifts
 Poor vein elasticity
IV ACCESS COMPLICATIONS
 Pain
 Infection / Phlebitis
 Allergic reaction
 Catheter shear
 Arterial puncture
 Circulatory overload
 Air embolism
 Necrosis
IV COMPLICATION ~
INFILTRATION
 Escape of fluid into surrounding tissue
 IV passes through vein
 IV dislodged
 Catheter inserted at too shallow an angle only entering fascia
 SSX:
 Edema at catheter site
 Continued IV flow after proximal vein occlusion
 Tightness, burning, pain at IV site
 Treatment:
 Discontinue IV
 Reestablish in opposite extremity or more proximal location
 Apply direct pressure
IV COMPLICATION ~ OCCLUSION
 Vein, catheter or tubing blockage
 1 st sign slow / no drip rate, blood in tubing
 Causes:
 Catheter position
 High BP overcoming flow
 Tourniquets!
 I nject 1 cc saline into IV to increase pressure
to overcome obstruction & reestablish flow
 If occlusion does not dislodge, discontinue IV
& re-establish in opposite extremity or
proximal to current site
IV COMPLICATIONS ~ HEMATOMA &
ARTERIAL PUNCTURE
 Hematoma
 Accumulation of blood in tissues
 Causes: vein perforation, improper
catheter insertion or removal
 Stop IV, apply direct pressure
 Arterial puncture
 Bright red spurting blood
 Suspect if you have a great IV that
does not flow
 Withdraw catheter, apply direct
pressure for 5 mins or bleeding stops
 Always check for pulse in the “vein”
IV COMPLICATIONS ~ SYSTEMIC
 Anaphylaxis
 Sensitivity to IV fluid or medication
 Treat according to allergic /
anaphylaxis protocol
 Pyrogenic reactions
 Pyrogens are foreign proteins capable
of producing fever secondary to
allergic reactions
 Characterized by abrupt fever with
chills, backache, HA, N/V, weakness
 Stop infusion immediately
 Treat according to allergic /
anaphylaxis protocol
IV COMPLICATIONS ~ NECROSIS &
INFECTION
IV COMPLICATIONS ~ CIRCULATORY
OVERLOAD
 Healthy adults can usually handle 2-3
extra liters of crystalloids
 Pts with cardiorespiratory or renal
disease can’t tolerate hemodynamic
stress from increased circulatory volume
 SSX:
 Dyspnea, JVD, HTN, rales, hypoxia, edema
 Treat: convert to saline lock, respiratory
distress protocol
IV THERAPY COMPLICATIONS ~ AIR
EMBOLUS
 Flushing IV line & replacing empty IV
bags limits likelihood of air embolism
 SSX:
 Respiratory distress, unequal BS, cyanosis
 Focal neurological symptoms
 Shock & cardiorespiratory arrest
 Treatment:
 LLR plus Trendelenburg position
 100% oxygen, treat specific symptoms
according to pertinent protocol
 Rapid transport
IV COMPLICATIONS ~ CATHETER SHEAR
 Part of catheter pinches
against needle & slices
through catheter creating
a free-flowing segment
 SSX similar to air embolus
 Treatment
 Surgical removal of the tip
 LLR & Trendelenburg
 Do not rethread
CHOOSING THE RIGHT SITE
 More than using a “BFN”
 Have favorite site, favorite
“Jelco”, favorite technique
 Have a back-up
 And back-up to your back-up
 Practice, practice, practice
ANTECUBITAL VEIN
DORSAL “DIGITAL” VEINS
EXTERNAL JUGULAR
ACCESSING EXTERNAL JUGULAR VEIN
INTRAOSSEOUS
 Administering fluids, blood products
& drugs into IO space
 Long bones consist of a shaft
(diaphysis), ends (epiphyses) &
growth plate (epiphyseal plate )
 IO space spongy cancellous
epiphyseal & diaphysis medullary
cavity.
 When in shock, peripheral veins
collapse making IV access dif ficult
 IO space always patent to rapidly
absorb fluids & drugs, similar to a
central line
GENERAL IO CONTRAINDICATIONS
 Cannot locate landmarks
 Fractures at / above site
 Amputations distal to site
 Previous surger y at site
 Infection at site
 Local vascular compromise
 Previous attempt in same site
 Osteogenesis imper fecta
 Occasionally dif ficult in
combative & the obese
IO INFUSION
Identify landmarks &
anatomy
Have all equipment
ready prior to starting
 Manufacturer-specific
device & equipment
 IV tubing
 Medications
SYYAMA J, ET AL. IO VS IV ACCESS WHILE
WEARING PPE IN A HAZMAT SCENARIO. P E C 2 0 07
 OBJECTIVE
 Determine time difference to obtain IO vs IV wearing HazMat
PPE
 METHODS
 22 EMT-Ps placed anterior tibial EZ-IOs & antecubital IVs
 Measured: time to skin access, vascular access & fluid infusion
 CONCLUSIONS
 With provider & mannequin in PPE, needle to skin time,
vascular access time, & fluid infusion time all favored EZ-IO
HUMERAL IO
HUMERAL APPROACH
 Humerus adducted
 Palpate midshaft proximally until
reach humeral head
 At shoulder greater tubercle protrusion is the insertion site
 With opposite hand “pinch” anterior & inferior aspects of
humeral head to confirm position of greater tubercle
 Stabilize arm, place IO at 90 degrees to skin
 Humeral cortex less dense than tibia so minimal force required
DISTAL TIBIA IO
DISTAL TIBIAL APPROACH
 Landmarks are anterior
distal tibia & medial
malleolus (middle
ankle bone protrusion)
 Medial insertion site, 2
finger widths proximal
to medial malleolus
 “Big Toe = IO”
PROXIMAL TIBIA IO
PROXIMAL TIBIA APPROACH
 Tibial tuberosity is round
protrusion distal to patella
 From tuberosity, move 1 in
medially to tibial plateau
 From tibial plateau, move
proximally 0.5 in towards
patella
 This is thinnest portion of
tibial bony cortex
STERNAL IO
STABILIZE THE IO
STABILIZE THE BABY
CENTRAL VENOUS ACCESS
 Large, deep veins do not
collapse until late shock
 Internal jugular, subclavian,
femoral
 Though IO “peripheral”, it’s flow
rate & placement in marrow
makes it function essentially as
central access
CENTRAL ACCESS DEVICE
 Surgically implanted device
permitting repeated access
to central venous circulation
 Generally located on
anterior chest near the 3 rd 4 th rib lateral to sternum
 Accessed with a special
needle specific to the device
 Requires special training
DIALYSIS FISTULA
 Dilated vein acts like
artery due to AV graft
 Do not access!
 Most common
complication is
bleeding
 Direct pressure +/proximal tourniquet
QUESTIONS?
MATHEMATICAL PHARMACOLOGY
PRINCIPALS
ASK YOURSELF…DO YOU FIND THIS FUNNY?
IF SO…YOU CAN SKIP THIS SECTION
IF YOU THINK THE ANSWERS ARE
OBVIOUS…REMEMBER THAT MATH IS HARDER AT
0 DARK THIRT Y
IV MEDICATION PACKAGING
Vials
 Single, multi-dose
 Draw air into syringe,
inject into vial, withdraw
drug
Ampules
 Tap neck area to drain fluid
 Using 4X4, snap neck of
vial, withdraw drug
 Dispose ampule pieces in
sharps container
Prefilled Syringes
 Remove caps, screw pieces
together
 Dispel air & use as standard
syringe
Dry Powder meds
 Depress plunger in vial to mix
with prepackaged saline
 Mix thoroughly until
particulate completely
absorbed
METRICS
 Decimal system based on
multiples of 10 measuring
length (meter), volume (liter),
weight (gram)
 Prefixes indicate fraction of
base used
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Micro = 0.00001
Milli = 0.001
Centi = 0.01
Kilo = 1,000
 Drugs packaged in dif fering
units of weight & volume so
conversion often required
BASICS OF DOSE CALCULATION
 Desired dose (amount of
drug)
 Drug concentration (total
weight of drug contained
in specific volume)
 Volume on hand (volume
of solution containing
drug)
PEDIATRIC DRUG DOSAGES
Most weight-based
 Length-based
resuscitation tape
 Pediatric wheel charts
 EMS field guide /
Smartphone app
Once weight known,
calculations same as
for adults
METRIC CONVERSIONS
1 gram (g) = 1000 milligrams (mg)
1 mg = 1000 micrograms (mcg)
1 liter (L) = 1000 milliliters (ml)
 If going from large to small value,
move decimal point to right
 If going from small to large value,
move decimal point to left
 1 Kg = 1000 g
 1 Kg = 1,000,000 mg
 1 Kg = 1,000,000,000 mcg
POUNDS TO KILOGRAMS
 Kg x 2.2 = pounds (lbs)
 1 Kg = 2.2 lbs
 3 am: (lbs/2) – 10% = kg
 To convert kg to lbs:
 Kg x 2.2 = lbs
 (Kg x 2) + 10% = lbs
CALCULATION EXAMPLE
 You want to give 5mg valium. Label states 10 mg in
2cc (10mg/2cc). How many cc’s do you give?
5mg x 2cc =
X cc
10 mg
 Therefore…1 cc of valium = 5mg of valium
 Phenergan ordered for 12.5 mg
 Supplied in 25 mg/ 2cc
 Therefore 12.5 mg Phenergan in 1cc
CALCULATING FLUID INFUSION RATES
 Adjust flow rate according to condition & protocol
 You must know:
 Volume to be infused
 Period over which it is to be infused
 Properties of the administration
 Therefore, flow rate is:
 Volume to be infused x gtt/mL of administration set/total time
of infusion in minutes = gtt/min
WEIGHT-BASED CALCULATIONS
Desired dose (D) x Patient’s kg Weight (W) = Volume to be
Administered (X)
Known dose on hand (H)
CALCULATION EXAMPLE
 You are giving 0.5 mg/kg IVP to an
80kg patient. Drug is prepackaged
in 100mg/10cc
 To determine total dose:
 0.5mg x 80kg = 40mg
 To determine total volume:
 40 mg x 10cc = 4cc total volume
100 mg
DRIP RATE CALCULATIONS
Desired Dose x Volume of IV Bag x Administration Set gtt = gtt / min
Amount of Drug
 Desired dose x Size of bag x gtt set = gtt/min
 Order is for 5 mg/min. You have 500cc NS, a 60
gtt/cc admin set & 2g of drug. How many gtt/min?
5mg/min x 500cc x 60gtt/ cc = 75gtt / min
2000mg
SIMPLER DRIP RATE
CALCULATION
 Volume x administration set / time
 (cc x gtt) / minutes
 You want to give a 500cc bolus using
a 15 gtt set over 1 hour
 (500cc x 15gtt) / 60 mins = 125 gtts/min
QUESTIONS?
REFERENCES
 Caroline’s Emergency Care in the
Streets 7 th Edition (Principles of
Pharmacology, Medication
Administration & Emergency
Medications). Jones & Bar tlett. 2013
 Pharmacology Drug Dosage
Calculations. Shelby County EMS
Training Division 2010
 Linscott et al. Emergency Care. IV
Access, Blood Sampling & IO
Infusions. Brady 2009.
 Photo credits (IV inser tion, EJ
cannulation) Scott Metcalf MD©
SUMMARY
P RE H OSP I TALMD@ G MAI L.C OM / W W W.EMS.C OM
 Find formula or system that
works for you
 Use Smartphone but phones die!
Back-up with paper, pen & brain
 IVF classes, pathophysiology &
indications
 Techniques, equipment &
indications for vascular access
 “6 rights” of drug administration
including basics of BLS & ALS
medication utilization
 When in doubt contact medical
control