PATIENT PREPARATIONCHAPTER 2 Part 2

PATIENT PREPARATION

• IV CATHETERS: catheters are ideal for all anesthetic procedures• Can treat/prevent ______________, _________________,

_______________________• Allows injection of medications such as antibiotics and

analgesics and allows constant-rate-infusions• Provides access to a vein in an emergency (cardiac arrest,

seizures ). Do not remove until animal is fully awake! • Allows _______________ agents to be injected (ex: thiopental)• Allows injection of _________________drugs

PATIENT PREPARATION

IV CATHETERS: Choose catheter size based on patient’s size and needRisks with catheter placement:

_______- always remove air from IV line before connecting to patient________________- don’t repeatedly advance and retract the stylet_________________________________- avoid by using infusion pump or

calculate drips/sec_____________________- wipe area of catheter placement with an antiseptic

and injection ports with alcohol____________________________ – Just because the catheter is there, doesn’t

mean all drugs should be given IV

PATIENT PREPARATION

• IV FLUIDS: the patient’s infusion rate will depend on body weight and procedure

•Fluids during surgery/anesthesia:• _________________mL/kg/hr• intended to compensate for vasodilation and fluid loss during

anesthesia/surgery

• Isotonic, polyionic replacement crystalloids are the first choice for fluid therapy in healthy patients.

PATIENT PREPARATION

• IV FLUIDS: fluid rates can be adjusted for those patients that are compromised• CV disease• Respiratory disease• Fluid rates for these patients are often kept at 5ml/kg/hr

• An animal with excessive hemorrhage or low blood pressure during surgery can have fluid rates increased• Dogs: up to 40mL/kg/hr for max of 1 hour• Cats: up to 20ml/kg/hr for max of 1 hour• A quick way to estimate amount of fluids to give:*Give ______mL of fluid for every

______mL of blood loss

PATIENT PREPARATION

ANIMALS IN SHOCK: these patients need even more rapid fluid ratesDogs: __________mL/kg/hrCats: ___________mL/kg/hr___________of the calculated dose is given and then patient re-evaluated

(a 10-20mL/kg bolus)Animals in shock may show the following signs:

Pale mucous membranesLow blood pressure_____________________ heart rate in compensatory & decompensatory

shock or slow heart rate in end stage shock

PATIENT PREPARATION

• IV FLUIDS: drip sets (administration sets) help determine how fast the fluids are administered• Patients greater than 10kg use a _____________ set

• Macrodrip sets are either 10gtt/mL or 15gtt/mL• VTI has 15gtt/mL sets

• Patients less than 10kg use a _______________ set• Microdrip sets are 60gtt/mL

PATIENT PREPARATION

• IV FLUID ADMINISTRATION SETS

MACRO MICRO

PATIENT PREPARATION

• IV FLUID ADMINISTRATION: most clinics have an IV fluid pump. The pump controls how many drops of fluid are delivered to the patient over a period of time.• If no pump is available, the anesthetist will need to calculate how many

drops of fluid should be administered to the patient in a period of time as well as monitor the fluids closely.

PATIENT PREPARATION

Step 1: Obtain the patient’s weight in kgs. If the patient’s weight was obtained in pounds, then you must divide by 2.2

Step 2: REMEMBER THE SURGICAL FLUID RATE: 10mL/kg/hr. Multiply the patient’s weight in kgs by 10. This will give you how many mLs the patient should receive in 1 hour known as the infusion rate.

Step 3: Determine the drip set necessary for the patient based on weight.Step 4: Multiply the patient’s infusion rate by the drip set.Step 5: Divide the number from Step 4 by 3600 (because there are 3600

seconds in 1 hour). THIS FINAL ANSWER WILL TELL YOU HOW MANY DROPS OF FLUID EACH SECOND THE PATIENT WILL RECEIVE EACH HOUR WHILE UNDER ANESTHESIA.

MATHMATH

PATIENT PREPARATION• Patient weighs 6 kg.

• Surgical fluid rate is 10mL/kg/hr: 6 x 10 = 60 mL/hr• Patient needs microdrip set: 60 x 60 = 3600• 3600/3600 = 1 drop/sec

• Patient weighs 12 kg.• Surgical fluid rate is 10mL/kg/hr: 10 x 12 = 120 mL/hr• Patient needs a macrodrip set: 120 x 15 = 1800• 1800/3600 = 0.5 drops/sec• 0.5 drops/sec is impossible to count, but if we multiply by 10 it will tell us how many

drops to administer in 10 seconds• 0.5 x 10 = 5 drops/10 sec

PATIENT PREPARATION: Fluid Administration

•Body fluids consist of water and solutes.•Water is 60% of body weight.•It is divided into _______and ______ (fluid in the vessels and fluid between the cells)•The other 40% is solutes•Blood volume is ____________of body weight in dogs & large animals and ___________-in cats

PATIENT PREPARATION• FLUID ADMINISTRATION• Body fluid solutes:

• ions• large plasma proteins or colloids,• small nonionic particles such as glucose and small proteins

• Electrolytes:• Cations

• Sodium (Na+)• Potassium (K+)• Magnesium (Mg2+)• Calcium (Ca2+)

• Anions• Chloride (Cl−)• Bicarbonate (HCO3

−)• Phosphates (HPO4

2− and H2PO4−)

• Proteins

PATIENT PREPARATION____________________ is the solute concentration maintained in all

body fluids. It is 300 mOsm/LPRINCIPLES OF WATER AND SOLUTE BALANCE:One-third of IV fluids administered will stay in the intravascular space.

Two-thirds will diffuse into the interstitial space.Colloids don’t pass freely through the vascular endothelium.The presence of colloids in the intravascular space draws water into the space

creating osmotic or oncotic pressure.Some solute concentrations (Ca2+, K+) must be kept within a narrow range to

maintain normal heart and muscle function.

PATIENT PREPARATION

•FLUID ADMINISTRATION FOR ANESTHETIZED PATIENTS• Anesthetic agents affect cardiopulmonary function by

decreasing inotropy and heart rate. Many agents also cause vasodilation. This results in an overall decrease in cardiac output and hypotension.• This affects oxygen delivery to the tissues• IV fluids increase circulating blood volume and cardiac output

PATIENT PREPARATION

•REVIEW OF IV FLUID TYPES: Crystalloids vs. Colloids

•CRYSTALLOIDS: the most common fluid type. Used for fluid replacement and maintenance. The 3 general categories of crystalloids are:• _____________________(isotonic, polyionic, replacement

solutions)• ___________solutions• ______________________solutions

PATIENT PREPARATION

•CRYSTALLOIDS: BALANCED ELECTROLYTE SOLUTIONS•Contain a solute profile similar to the extracellular fluid

since dehydration , general diseases, and peri-operative hemorrhage deplete the ECF first.• This means higher concentrations of Na+ and Cl-

• Examples: Plasmalyte, Normosol, Lactated Ringer’s

PATIENT PREPARATION• CRYSTALLOIDS: SALINE SOLUTIONS

• Contain ONLY Na+ and Cl-

• Examples: Normal Saline & hypertonic Saline

• NORMAL SALINE(0.9%): used to flush body cavities, flush catheters, blood transfusions• HYPERTONIC SALINE(3%, 5%, 7%): very concentrated and quickly draws

water into the intravascular space and supports blood pressure, but rapidly diffuses out into the interstitial space. Used for profound hemorrhage, shock, increased intracranial pressure

PATIENT PREPARATION

•CRYSTALLOIDS: DEXTROSE SOLUTIONS (2.5%, 5%)•Used in cases of hypoglycemia, neonatal,

debilitated animals, hyperkalemia, patients receiving insulin•Don’t use as the sole fluid. The sugar is rapidly

metabolized to CO2 and water. The free water diffuses out into the interstitial space.

PATIENT PREPARATION

•COLLOIDS: large molecules that do not readily leave the intravascular space• These are helpful in maintaining blood volume and

pressure• Less side effects than hypertonic saline• Rapidly pulls water into the intravascular space• Examples: __________ or __________,

__________________, _________________________

PATIENT PREPARATION

COLLOIDS: PLASMA OR BLOODContains albumin, clotting factors, globulinsUsed in animals with acute blood loss, anemia, hypoproteinemiaExpensive

COLLOIDS: BLOOD SUBSTITUTESUsed for acute hemorrhage and anemiasOxyglobin contains hemoglobin molecules of bovine origin similar to red

blood cells that are able to carry oxygen.The benefit is that there is no cross-match requiredTHIS PRODUCT IS NOT CURRENTLY AVAILABLE

PATIENT PREPARATION

COLLOIDS: SYNTHETIC COLLOIDS (*Hetastarch, *Vetstarch, Dextran)More readily available than blood productsLess expensive and longer shelf life than blood

productsUsed in cases of shock, hypoproteinemiaUsually administered IV at rate of 10-20mL/kg/day;

bolused slowly over 15-60 minutes30%-60% remains in the plasma after 24 hours, and

a smaller percentage remains in the plasma for as long as days to weeks after administration.

PATIENT PREPARATION

ADVERSE EFFECTS OF FLUID ADMINISTRATION____________________– more likely in patients that are <5kg or those

with cardiac or renal disease *reduce infusion rates Ocular/nasal discharge Chemosis Subcutaneous edema Increased lung sounds Increased respiratory rate Dyspnea Coughing, restlessness

_____________________ – dilution of the RBC’s and plasma proteins.