Small Animal Nursing II Exam 2 - Aseptic Technique, Anesthesia, and Critical Care Nursing

Asepsis

Condition of sterility wherein no living organisms are present

Exogenous route

Source of microorganisms by way of air, surgical supplies, patient's skin, or surgical team

Endogenous route

Source of microorganisms by way of bacteria through the bloodstream

Bacteremia

Bacteria in the blood

Doubles

For every hour under general anesthesia, the risk of infection ____

Sterilization

The elimination or destruction of all living organisms from a material

Disinfection

The destruction of vegetative forms of bacteria but not the spores

Filtration (i.e pharmaceuticals)

Use of a filter to separate particulate material from liquids or gases

Radiation (i.e gloves and suture materials)

Destroys microorganisms without causing significant temperature elevation

Heat

The most common physical method of sterilization

Lasts 7 weeks in a closed cabinet (3 weeks in an opened cabinet)

Why is it recommended to package instruments in a double wrapped muslin pack for sterilization?

Flash sterilization (emergency sterilization)

Unwrapped instruments are placed in a perforated metal tray for sterilization and then are carried to the operating room with the use of detachable handles

To reduce condensation formation

Why should you allow packs to cool slowly after sterilization?

Assurance of sterility

Why is quality control of an autoclave important?

Glutaraldehyde

Most common method of liquid sterilization

Gas sterilization (ethylene oxide and hydrogen peroxide gas plasma)

Used for items that cannot tolerate the high temperatures or steam associated with autoclaving

Povidone-iodine

One of the most common surgical scrubs in veterinary hospitals

Iodine

Chemical disinfectant used for surgical prep, topical wound therapy, and joint/body cavity lavage

4-6 hours

The bactericidal activity of iodine is

Chlorhexidine

Chemical disinfectant effective against bacteria, mold, yeast, and viruses

Dilute 1:40 with sterile water or saline for 0.05% solution

What is the proper dilution for chlorhexidine?

Alcohols

Chemical disinfectant that are solely bactericidal

Aldehydes

Chemical disinfectants that are toxic and irritating with antimicrobial effects

Cold sterilization (chlorhexidine or glutaraldehyde)

Soaking instruments in disinfecting solutions for minor procedures or equipment that cannot tolerate other sterilization methods

Completely disassembled and gas sterilized or cold sterilized

How should arthroscopic and laparoscopic equipment be sterilized?

• Clip hair with No. 40 clipper blade, 5 to 15 cm around surgery site

• Clip potentially infected areas last

• Pre-surgical scrub alternating between antiseptic scrub and alcohol

• Final sterile surgical scrub after animal is positioned on surgery table

Describe how to appropriately prepare a patient's skin for surgery

• Only touch nonsterile items

• Never reach over sterile fields

• Always face the sterile field

Describe how to maintain sterility while in surgery when you yourself are nonsterile

• Only touch sterile items or areas

• Remember that neckline, back, armpit area not sterile

• Keep hands above waist level

• Always face the sterile field

Describe how to maintain sterility while in surgery when you yourself are sterile

An absence of sensation that affects the whole body or an isolated part or region of the body

What is anesthesia?

Unconsciousness and insensibility to feeling and pain induced by administration of anesthetic agents

General anesthesia is characterized by

Loss of sensation in a localized part of the body without loss of consciousness

Localized anesthesia is characterized by

∙Cardiac output

∙Blood pressure

∙Respiratory drive

∙Central nervous system function

Anesthesia is considered a high risk procedure because of potential adverse changes involving

Induction

The process that is used to take the patient from a state of consciousness to general anesthesia

Maintenance

The process used to keep the patient under general anesthesia until recovery

Procedures that do not require the patient to be unconscious

What is local anesthesia used for?

∙ Relax patient or provide sedation

∙ Ease induction and recovery

∙ Reduce amount of anesthesia needed

∙ Provide muscle relaxation

∙ Provide analgesia

Identify reasons premedications are given to patients before induction of general anesthesia

8-12 hours for food (less for patients < 2 kg)

2-4 hours for water

How long should food/water be withheld before a dog or cat goes under anesthesia?

American Society of Anesthesiologists (ASA)

Assigns classification on the basis of a patient's condition to guide anesthetist in patient management

ASA I (Minimal risk)

Identify the ASA classification of a normal, healthy patient undergoing an elective procedure such as a spay or neuter

ASA II (Low risk)

Identify the ASA classification of a patient with mild systemic disease such as obesity, mild dehydration, or skin tumors

ASA II

Identify the ASA classification of a neonatal or geriatric patient

II

Any brachycephalic patient would automatically be considered ASA class

ASA III (Moderate risk)

Identify the ASA classification of a patient with severe systemic disease such as anemia, moderate dehydration, or major organ disease

ASA IV (High risk)

Identify the ASA classification of a patient with severe, life-threatening systemic disease such as a ruptured bladder, pyometra, pneumothorax, or internal hemorrhage

ASA V (Extreme risk)

Identify the ASA classification of a patient that is not expected to survive without operation (i.e severe head trauma, pulmonary embolus, GVD, end-stage major organ failure)

IV induction

Induction of anesthesia administered to effect

IM induction

Induction of anesthesia administered at 2-3x the corresponding IV dosage

Anesthetic masks

Used to administer oxygen or anesthetic gases to non-intubated patients

300 ml/kg/minute

Anesthesia induction using a mask is accomplished at an O2 flow rate of

Anesthetic chamber (higher risk)

Box that utilizes a semi-closed rebreathing system to induce general anesthesia in small or aggressive patients

Propofol (3-6 mg/kg to effect)

An ultra-short-acting IV anesthetic used to induce and maintain general anesthesia

Given IV slow at 1/4th the calculated dose every 30 seconds to effect

How is propofol administered for anesthesia induction?

General anesthesia in 30-60 seconds with duration of 2-5 minutes

How long does it take propofol to induce anesthesia, and how long does it last?

Apnea

What is a major caution associated with propofol?

Inhalant anesthetics

Identify the most common method of maintaining anesthesia

Endotracheal tube

Used to maintain an open airway in anesthetized patients

∙ Maintain open airway

∙ Minimize risk of aspiration of blood, stomach contents, etc

∙ Ease supplemental oxygen flow

∙ Allow anesthetist to ventilate patient

Identify the functions of an ET tube

Allows the patient to ventilate even if the ET tube becomes occluded

Identify the function of the Murphy's eye component of an ET tube

Pilot balloon

Access site for inserting air into the cuff of an ET tube

Laryngoscopes

Used to visualize the larynx while placing endotracheal tubes

Carrier gas supply (A)

Component of the anesthesia machine that delivers oxygen to the patient at a controlled flow rate

Oxygen

The carrier gas supply delivers _____ to the patient

Anesthetic vaporizer (B)

Component of the anesthesia machine that vaporizes liquid inhalant anesthetic and mixes it with oxygen

Breathing circuit (C)

Component of the anesthesia machine that delivers the anesthetic and oxygen mixture to the patient and conveys expired gases away from the patient

Scavenging system

Disposes of waste and excess anesthetic gases

∙ Waste gas exits from the pop-off valve (A)

∙ The waste flows through the interface (B)

∙ Moves into a canister (C) or an outlet pipe in the ceiling

How does the scavenging system dispose of waste?

Green (US) or white (international)

What color is an oxygen cylinder?

Blue

What color is a nitrous oxide cylinder?

∙ Never leave an unattended compressed gas cylinder unsupported or lying on its side

∙ Never attempt to remove the valve or index pins

∙ When turning a tank on, keep skin and eyes clear of the valve port

∙ Do not use oxygen near any source of ignition

Identify the rules for handling a compressed gas cylinder

Isoflurane and sevoflurane

An anesthetic vaporizer holds liquid inhalant anesthetic such as

Minimum alveolar concentration (MAC)

Percent concentration of an agent required to prevent a response to surgical stimulation in 50% of patients

1.5x the minimum alveolar concentration (Iso/sevo dial setting of 2.0)

A baseline dial setting of approximately _____ is required to reach surgical anesthesia in most patients

A scavenging system

A breathing circuit circulates fresh gases to the patient and conveys waste gases to _____

ET tube is not in the trachea or the patient isn't breathing

Lack of movement in a reservoir bag or unidirectional valves could indicate

Pressure manometer

Indicates pressure in a breathing circuit and in the patient's lungs

Oxygen flow and adjustment of the pop-off valve (Should read no more than 20 cm H2O)

A pressure manometer is influenced by

Corrugated breathing tubes

Complete the breathing circuit by carrying anesthetic gases to and from the patient

Directs expired gases through a soda lime canister for absorption of CO2, and then is rebreathed by the patient

How does a rebreathing circuit work?

Non-rebreathing circuit

Designed to deliver oxygen and anesthetic gases with less resistance to breathing in small patients

< 7 kg

Non-rebreathing circuits are appropriate for patients _____

Tip of nose to thoracic inlet

How should you measure the length of your ET tube?

• Hypoventilation

• Hypoxia

• Dead space

What can result if an ET tube is too short for the patient?

Hypoxia

Low levels of oxygen in the body tissue

Dead space

Breathing passages and tubes that convey fresh oxygen to the alveoli but in which no gas exchange can occur

Glottis

Structure between the vocal folds which move apart when the patient inspires and relax as patient expires

Laryngospasm (treated with 0.1 ml of 2% injectable lidocaine in cats)

Closing of the glottis during intubation, especially common in cats

• Pulmonary aspiration

• Leaking of anesthetic gas, polluting the surgical environment

An under-inflated ET tube cuff poses a risk of

• Tracheal mucosal irritation

• Tracheal wall ischemia leading to necrosis

An over-inflated ET tube cuff poses a risk of

Anesthetic monitoring

The cornerstone of successful anesthesia

Stage I

Plane of anesthesia referring to the period of voluntary movement

Patient gradually loses consciousness and ability to stand, and becomes recumbent

Describe anesthetic plane stage I

Stage II

Plane of anesthesia referring to the period of involuntary movement

• "Excitement stage" where patient loses voluntary control

• Irregular breathing pattern

• Vocalizing

• Reflex struggling, or paddling

Describe anesthetic plane stage II

Stage III of the anesthetic plane

The period of surgical anesthesia

• Progressive muscle relaxation

• Decreasing HR and RR

• Loss of reflexes

Describe anesthetic plane stage III

Stage IV of the anesthetic plane

A period of anesthetic overdose

Heart stops, and death follows quickly unless rapid action is taken

Describe anesthetic plane stage IV

Between stage II and III

What is the ideal anesthetic plane for a patient during surgery?

• Palpebral reflex

• Swallowing

• Corneal reflexes

• Jaw tone

• Eye position and pupil size

• Response to surgical stimulation

Identify visual monitoring parameters used to determine if your patient is in the appropriate anesthetic plane

Normal: 60-180 bpm

Anesthesia: 60-150 bpm

Report to DVM: < 60 or > 140

Identify a normal HR for a conscious dog versus one who is anesthetized