Anesthesia Flashcards
Important pre-anesthesia questions
Fasting? Current condition? Changes in condition since scheduling? Current in preventive care? What is the Scheduled procedure? Medications?
Effects of anesthesia
Light to heavy sedation, local anesthesia, general anesthesia, muscle relaxation, analgesia, combination
General anesthesia
Unconsciousness and insensibility to feeling and pain induced by administration of anesthetic agents given alone or in combination
Uses of general anesthesia
General surgery or painful procedures without patient movement or personnel injury
Anesthetic induction
The process used to take the patient from a state of consciousness to general anesthesia
Anesthetic maintenance
The process used to keep the patient under general anesthesia until recovery
Local anesthesia
Loss of sensation in a localized body region or part induced by administration of a drug or other agent without loss of consciousness
Use of local anesthetic
Used for procedures that do not require the patient to be unconscious and for adjunct pain control
Premedication (preanesthesia)
Administration of an agent or agents before induction of general anesthesia to calm and relax the patient, ease induction and recovery, minimize adverse effects, reduce the amount of general anesthetic needed, provide muscle relaxation, provide pain control
Sedation
A state of calm or drowsiness
Tranquilization
A state of relaxation and reduced anxiety
Neuroleptanalgesia
State of profound sedation and analgesia produced by simultaneous administration of an opioid and a tranquilizer
Uses of neuroleptanalgesia
Perform minor procedures such as wound treatment or radiography, and to induce general anesthesia in compromised patients
Balanced anesthesia
Concurrent administration of two or more anesthetic drugs with complementary effects
Reasons patient preparation is important
- Minimize the likelihood of preventable complications (i.e. aspiration)
- All tx of any problems that may endanger the patient (i.e. Dehydration)
- Allow the vet to make anesthetic drug choices based on facts about the patient’s condition
- make the anesthetist aware of potential problems that the patient may experience during the procedure
Fasting recommendations
Dogs and cats: 8-12 hours food, 2-4 water
Horses: 8-12 food, 0-2 water
Cattle: 24-48 food, 8-12 water
Small ruminants: 12-18 food, 8-12 water
Physical assessment
Focus of nervous, cardiovascular, pulmonary systems.
- level of consciousness/mentation
- general body condition (BCS, hydration)
- weakness, abnormalities, recumbency
- parasites, wounds, tumors, external lesions
- body orifices for external signs of dz: diarrhea, nasal discharge, hematuria, vaginal discharge
- Vital signs/TPR stats
- respiratory effort
- auscultate lungs
- palpate pulse and auscultate heart
Purpose of diagnostic tests w/anesthesia
Uncover abnormalities that may impair the patient’s ability to compensate, that may lead to unanticipated complications, or that may impair the patient’s ability to eliminate the anesthetics
Patient stabilization
Tx/correction of dehydration, anemia, cardiac arrhythmias, respiratory compromise, major organ failure, electrolyte/acid-base imbalance.
May involve antibiotics, analgesics, fluids, blood, oxygen, etc.
Physical status classification: P1
Minimal risk. Normal healthy patient.
Patients undergoing elective procedures
Physical status classification: P2
Low risk. Patient w/mild systemic disease.
Neonatal, geriatric, obese, brachycephalic patients.
Mild dehydration.
Skin tumor removal.
Physical status classification: P3
Moderate risk. Patient with severe systemic disease.
Anemia. Moderate dehydration. Compensated major organ disease.
Physical status classification: P4
High risk. Patient with severe systemic disease that is a constant threat to life.
Ruptured bladder, internal hemorrhage, pneumothorax, pyometra
Physical status classification: P5
Extreme risk. Moribund patient that is not expected to survive without the operation.
Severe head trauma. Pulmonary embolus. GDV. End-stage major organ failure.
Objective of anesthesia
Produce loss of sensation in the whole body, or a specific body part or region, and to provide muscle relaxation and alteration of consciousness appropriate to the procedure. Patient safety must be preserved and adverse effects minimized. Pay special attention to respiratory and cardiovascular
Anesthetic depth stage 1
Conscious/disoriented HR/RR normal to increased Eyes central pupils normal size PLR's normal All reflexes present
Anesthetic depth stage 2
Excitement stage.
Struggling, vocalizing, paddling
Patient can release epinephrine due to stress causing cardiac arrhythmias
Anesthetic depth stage 3: plane 1
Light anesthesia Unconscious May be gagging/swallowing, but decreased HR/RR normal w/strong pulse Eyes may rotate or stay central Pupil size normal/partially constricted PLR's decreased palpebral/pedal reflexes decreased
Anesthetic depth stage 3: plane 2
Surgical anesthesia Immobilized HR/RR/BP slightly decrease RR may be shallow Eyes often ventromedial Pupil size normal PLR's slow Reflexes decreased or absent
Anesthetic depth stage 3: plane 3 or 4
Deep anesthesia or near death Immobilized HR/BP decreased Weak pulse Shallow breaths CRT increased Pale MM Eyes central Pupils moderately dilated PLR's slow or absent Reflexes absent and muscle tone flaccid
Anesthetic depth stage 4
Moribund - anesthetic overdose
Immobilized
Cardiovascular collapse
Weak pulse, barely palpable
