Anesthesia Definitions, Monitoring Standards Flashcards
ASA Standards II
o During all anesthetics, oxygenation, ventilation, circulation, temp continually evaluated
o Repeated regularly, frequently in steady rapid succession:
Gas analyzer in BC – measures FiO2, SpO2
Qualitative eval of breathing: chest excursions, RR/character, capnography, airway pressures
ECG, HR, ABP at least Q5’
* Additionally one of the following: pulse palpation, heart sound auscultation, IBP trace monitoring, pulse plethysmography, oximetry
Body Temp
ACVAA 2009 Consensus Statement Position
o “Frequent and continuous monitoring and recording of vital signs and peri anesthetic. By trained personnel and intelligent use of various monitors are requirements for advancing quality of anesthesia care of veterinary patients”
ACVAA Personnel Standards
“Ideally, veterinarian technician or other responsible personnel remain with the patient continuously and be dedicated to that patient only”
Check status, parameters at least Q5’ – if responsible for other tasks, “audible heart and respiratory monitors must be available”
ACVAA Parameters
Circulation:
* Mandatory: pulse palpation for rate, rhythm, quality; MM/CRT
* Recommended: intermittent HR, rhythm, BP (IBP, NIBP)
Oxygenation
* SpO2, PaO2 if indicated
Ventilation
* Thoracic wall movement, RBB movement
* Capnography
* PaCO2, respirometry/spirometry when indicated
Temp: rectal or esophageal during ax, recovery
Recommended Record Keeping
o Pre, peri, initial recovery periods
o All drugs: dose, time, ROA, AEs/ADRs
o Monitored variables, minimum Q5’ – HR, RR, O2 status, BP, temp
o All atypical, AEs for legal reasons, future reference
Recovery Monitoring
o RR, character
o MM, CRT
o PR, quality
o Body temp
o Analgesic needs
o Other parameters as indicated by comorbidies (eg glucose in diabetics, etc)
CEPSAF
o Factors assoc with increased odds of ax-related death: poor health status, increasing age, extremes of weight, increasing procedural urgency/complexity, ETT, fluid therapy
Inhalation
Anesthetic gases or vapors inhaled in combination with oxygen
Injectable
Anesthetic solutions injected IV, IM or SC
o Other injectable routes = intrathoracic, IP (not recommended)
Total intravenous anesthesia (TIVA), partial intravenous anesthesia (PIVA), targeted controlled infusions (TCI):
utilize IV infusion of one or more drugs to produce suitable anesthetic state
o Some automated infusion systems available allow input of patient parameters, PK information for specific drugs allow targeting of predetermined plasma concentration (TCI)
PO or Rectal
routes ordinarily used for liquid anesthetics, analgesics, or suppositories
o Greater degree of inter-species, inter-individual variability in dose-response relationship of orally administered drugs due to differences in absorption, first-pass hepatic metabolism
Local and Conduction
Anesthetic drug applied topically, injected locally into/around surgical site (field block) or injected around large nerve trunk supplying specific region (conduction or regional nerve block)
For conduction or regional nerve block, injection may be perineural or into epidural/subarachnoid space
Electronarcosis, electroanesthesia, or electrosleep
electrical current passed through cerebrum to induce deep narcosis
o Form of ax never gained popularity –> rarely used in veterinary practice
o Should not be confused with inhumane practice of electroacupuncture
Transcutaneous electrical nerve stimulation (TENS, TNS, TES):
local analgesia induced by low-intensity, high-frequency electric stimulation of skin through surface electrodes
o Many similarities to electroacupuncture
Hypnosis
non-drug induced trance-like state sometimes employed in rabbits, birds
condition of artificially induced sleep, or trance resembling sleep, resulting from moderate depression of the CNS from which patient is readily aroused
Twilight Anesthesia
state of heavy sedation where patient still conscious, but cooperative, little to no recall (amnesia)
o Technique popular for OP ax in human med for dx px, minor sx px when combined with LA, additional analg drugs
o Term commonly used by laypeople to connote heavy sedation does not refer to specific anesthetic px or technique
Acupuncture
fine, long needles to induce analgesia
o Additional modalities of acupuncture point stimulation utilized: mechanical, electrical stimulation
Hypothermia
body temperature decreased, either locally or generally, to supplement insensitivity, decrease ax drug requirement, reduce metabolic needs
o Neonates, patients undergoing CV sx
Anesthesia
derived from Greek term anaisthaesia, “insensibility” descries loss of sensation to entire or any part of body
o Induced by drugs depress activity of nervous tissue locally, regionally, or within CNS
o Both CNS stimulants, depressants = useful general anesthetics
Analgesics
drugs used in management of pain in patients
o Derived from an (negative/without) and alges(is) (pain)
o Clinical management of pain results in varying degrees of effectiveness that represent states of hypoalgesia
o Administration of an analgesic drug does not necessarily create the state of analgesia
Hypoalgesia
decreased sensation of pain
Analgesia
absence of pain IRT stimulation which would normally be painful, term generally reserved for state in conscious patient
Nociception
neural process of encoding noxious stimuli, physiological process that underlies conscious perception of pain
o Does not require consciousness
o Can continue unabated during GA if techniques that interrupt or inhibit transduction, transmission, or modulation of nociceptive stimuli not included
Pain
Unpleasant sensory, emotional experience associated with actual or potential tissue damage, or described in terms of such damage
Tranquilization
results in behavioral change when anxiety relieved, patient becomes relaxed but remains aware of surroundings
o Tranquilizers = drugs that result in tranquilization when administered, anxiolytic or anti-anxiety drug to describe those that result in both reduced anxiety, relaxation
Sedation
state characterized by central depression accompanied by drowsiness, some degree of centrally induced relaxation
o Patient generally unaware of surroundings
o Can become aroused, generally responsive to noxious stimulation
o Not recommended by themselves to immobilize patient during times when painful stimuli likely to occur
Narcosis
drug-induced state of deep sleep from which patient cannot be easily aroused
o +/- Antinociception, depending on techniques, drugs used
Local Anesthesia/Analgesia
loss of pain sensation to a circumscribed body area
Regional Anesthesia/Analgesia
insensibility to pain in larger, though limited, body area usually defined by pattern of innervation of the effected nerve(s)
GA
drug-induced unconsciousness characterized by controlled but reversible depression of the CNS, perception
o Patient not arousable by noxious stimulation
o Sensory, motor, and autonomic reflex functions attenuated by varying degrees, depending on specific drug(s) and technique(s) used
Surgical GA
state/plane of ax that provides unconsciousness, amnesia, muscular relaxation, and hypoalgesia sufficient for painless surgery
balanced Ax
achieved by simultaneous use of multiple drugs and techniques
o Drugs targeted to attenuate specifically individual components of anesthetic state –> amnesia, antinociception, muscle relaxation, alteration of autonomic reflexes
Dissociative Anesthesia
induced by drugs that dissociate thalamocortic, limbic systems
o Characterized by cataleptoid state, eyes remain open, swallowing reflexes intact
o SkM hypertonus persists unless strong sedative, peripheral/central muscle relaxant co-administered
MAIN FOUR COMPONENTS OF AX
- Unconsciousness
- Immobility
- Amnesia
- Muscle Relaxation
