Transcript File

PARAMEDIC
PHARMACOLOGY:
INTRAVENOUS FLUIDS &
DRUG CALCULATIONS
Amy Gutman MD
EMS Medical Director
[email protected]
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 or inappropriate, ask physician to repeat the order
 Repeat back for confirmation the 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
 Knowledge necessary
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
 Name of person
administering drug
 Patient’s response to drug
DRUG CHECKS & LOGS
 At beginning of each shift, check drugs, supplies & equipment
 Not expired
 Not 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 & at base storage
 Drug log must be kept for at least 3 years
 Medical director DEA number used to order narcotics
UNIVERSAL PRECAUTIONS
 Treat all bodily fluids as
infectious
 I don’t shake pt’s hands without
gloves (especially kids)
 PPE, gloves & protective
eyewear at all times
 Include full facial protection if
possible splatter
 CDC states hand-washing
most effective method to
prevent the disease spread
ASEPSIS
 Routine & thorough hand -washing
 Hand-sanitizer before & after every
patient contact if no easy access to
soap & water
 Keep equipment in clean conditions
with disinfection between each
patient & every shift
 Antiseptics prior to any invasive
procedure
 Check linen, equipment & supplies
prior to use for intactness,
cleanliness
CONTAMINATED MATERIALS CLEANING
OR DISPOSAL
 After needle penetrates
skin, it is contaminated
 After needle unsheathed, it
is a weapon
 Immediately dispose of
sharps in a puncture-proof
sharps container
 Follow your agency protocol
for disposal of infectious
waste & cleaning of
contaminated equipment
BASIC PHARMACOLOGY KNOWLEDGE
 Specific protocol
 Specifics to that medication or IVF:





Indications / Contraindications
Therapeutic effects
Side effects
Appropriate dose & re-dosage
Need (+/-) for medical control
 Allergies:
 Known by patient
 Obtain from reliable source if not from patient
 Check for medic-alert jewelry or tags.
INTRAVENOUS FLUIDS
CHOOSING APPROPRIATE IVF
 Based upon presenting
& underlying illness or
injury
 Even a small amount of
the poorly chosen fluid
may be harmful to a
patient
 Most agencies have
limited choices of each
IVF class – 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
 0.45% Normal Saline
 Dilutes serum by pulling water
from vascular compartment into
interstitial compartment
 Used for hyperosmolar conditions
like severe dehydration
 Leads to hyponatremia if plasma sodium normal as has lower
concentration of sodium than serum
 Cells swell & burst from increased osmotic pressure
 If rapidly infused causes cerebral edema & central pontine
demyelinosis
 May cause sudden fluid shift from intravascular space to
intracellular space leading to cardiovascular collapse
 Slower but deadly is third spacing ~ abnormal shift into serum
if not enough protein to “hold” fluid in vascular space
IV FLUIDS: HYPERTONIC
 1 .8% - 10% saline, mannitol
 Osmolarity higher than serum as
has more particles than serum
 Pulls fluid & electrolytes from the intracellular to
intravascular (ECF) compartment
 Large volumes cause hypernatremia & severe dehydration
 Cells may collapse from increased extracellular osmotic pressure
 A little goes a long way to:
 Increase BP
 Reduce cerebral edema
IV FLUIDS: ISOTONIC
 0.9% Normal Saline
 Principal resuscitation fluid
 Contains sodium, potassium, chloride in almost same
concentrations as “body water” or “plasma”
 Iso-osmolar compared to plasma so stays almost entirely in
the extracellular space
 3-1 replacement rule: 3cc isotonic solution needed to replace
1 mL of blood
IV THERAPY: COLLOIDS
 Albumin, blood, dextran, hetastarch
 Contain particles which do not readily
cross semi-permeable membranes
 Volume stays almost entirely 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
OXYGEN-CARRYING SOLUTIONS
 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, but rarely
used outside trauma research
institutions or the military
 PolyHeme, HemoPure (HBOC HemoglobinBased O2 Carrying Solutions)
CHOOSING THE RIGHT SITE:
ANATOMY & TECHNIQUES
CHOOSING AN IV CATHETER
 Based on purpose of IV, patient
age, location
 Over-the-needle catheters preferred
in prehospital setting




Readily secured
Minimally cumbersome
Allow for some patient movement
Do not need to immobilize the entire
limb
 Sized by diameter (gauge)
 Smaller gauge = larger diameter
 Choose largest-diameter catheter for
chosen vein
 New needles retract after insertion
EQUIPMENT NEEDED
 Gloves, PPE
 Tape & bio-occlusive
dressing
 Tourniquet
 Alcohol, betadine,
chlorhexadine
 Arm board
 Sharps container
EQUIPMENT NEEDED
 IV solution
 Medical: NS
 Trauma: LR or NS*
 Medication drip: NS or 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
 Most packaged in clear
plastic bags
 Labeling:
 Fluid type
 Expiration date
 Do not use after
expiration date, appear
cloudy, discolored, with
visible particulate, or if
packaging not intact
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
 “Blood-band” identifies blood type & blood product hung
 Blood must be checked against bracelet & verified by medic even if
already checked by nursing
 Blood administered through specific tubing
 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
& insert into new IV bag /
bottle
 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 catheter passes through vein
 IV becomes dislodged
 Catheter inserted at too shallow an angle only entering fascia
 SSX:
 Edema at the 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 is decreasing / no drip rate or
blood in tubing
 Causes:
 Position of catheter within the vein
 BP overcoming flow
 Tourniquets!
 I nject 1-5 cc saline into IV to gently 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
around IV
 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, after checking for
obstruction
 Withdraw catheter, apply direct
pressure for 5 mins or bleeding stops
 Always check for a pulse prior to
cannulation
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 handle 2-3 extra
liters of crystalloids
 Problems pts with cardiorespiratory
or renal dysfunction who can’t
tolerate hemodynamic stress from
increased circulatory volume
 SSX:
 Dyspnea, JVD, HTN, rales, hypoxia, edema
 Treat by converting 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 & 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 a favorite site,
favorite “Jelco” &
favorite technique
 Have a back-up
 And a back-up to your
back-up
 Practice, practice,
practice
ANTECUBITAL VEIN
DORSAL “DIGITAL” VEINS
EXTERNAL JUGULAR
ACCESSING EXTERNAL JUGULAR VEIN
INTRAOSSEOUS
 Technique of administering fluids, blood
products & drugs into intraosseous space
of tibia, humerus or sternum
 Long bones consist of a shaf t (diaphysis),
the ends (epiphyses) & growth plate
(epiphyseal plate )
 IO space is spongy cancellous epiphyseal
& diaphysis medullar y 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
 Supine position, humerus adducted
 Palpate midshaft humerus
proximally until reach humeral head
 At shoulder there is a protrusion
(greater tubercle) which 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 degree
angle 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
inch medially to tibial
plateau
 From tibial plateau, go
proximally 0.5 inch towards
patella
 This is thinnest portion of
tibial bony cortex
STERNAL IO
STABILIZE THE IO
STABILIZE THE BABY
CENTRAL VENOUS ACCESS
 Large, deep veins that 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
an artery due to AV
graft
 Do not access!
 Most common
complication is
bleeding
 Direct pressure +/proximal tourniquet
MATHEMATICAL
PHARMACOLOGY
PRINCIPALS
IV MEDICATION PACKAGING
 Vials
 Single or 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 of 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
particulates completely
absorbed
METRICS
 Decimal system based on
multiples of ten measuring
length (meter), volume
(liter), weight (gram)
 Prefixes indicate fraction of
base being used




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
Necessary information:
 Desired dose (amount of
drug)
 Drug concentration (total
weight of drug contained
in specific amount of
volume)
 Volume on hand (volume
of solution containing
drug)
PEDIATRIC DRUG DOSAGES
 Most pediatric drugs
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
 1Kg = 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 will 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 / 1cc
CALCULATING FLUID INFUSION RATES
 Adjust flow rate according to pt’s condition & per 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 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
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
 Find math formula or system that
works for you
 Use Smartphone but remember that
phones die! Back-up with paper, pen
& brain
 IVF classes, pathophysiology &
indications
 Dif ferent techniques, equipment
& indications for vascular access
 “6 rights” of drug administration
including basics of BLS & ALS
medication utilization
 When in doubt contact medical
control