Lecture 13 10/22/24 Flashcards
What are the complications of swine anesthesia that arise due to genetics?
-Porcine Stress Syndrome
-Pale-Soft-Exudative Pork
-Malignant Hyperthermia
Which type of pig is considered susceptible to malignant hyperthermia?
meat breeds
What are the special considerations taken into account with swine anesthesia?
-very intelligent
-social behavior
-feeding schedule/temp fluctuations
-drug residues in meat
-personnel safety
What are the characteristics of fasting in swine?
-omnivorous monogastric animals
-12 hrs of fasting in adults
-3 hrs of fasting in juveniles
-1 hr of fasting in neonates
-maropitant/cerenia used for vomiting
What history is typically obtained from an owner?
-behavior
-food intake
What are the characteristics of a swine physical exam?
-begin with visual observations of mentation and ambulation
-move to hands-on exam to best of ability
-stress levels will affect vitals
What is important regarding the age of swine undergoing anesthesia?
the rise in pigs as pets has led to more geriatric swine undergoing anesthesia
Which drugs can be used for oral tranquilization in swine?
-gabapentin
-trazodone
-clonazepam
How can a pig’s stress be reduced in hospital?
-allowing time for animal to acclimate to hospital environment
-food enrichment/distraction
What are the characteristics of physical restraint in swine?
-poorly tolerated
-aggressive physical restraint not recommended
-want to minimize stress from handling
-minimizing stress reduces exertion hyperthermia
Which techniques can be used to physically restrain a pig?
-towel wrap
-board
-snout twisting w/ snare
-cart
Which aspects of pig anatomy and physiology pose a challenge to anesthesia?
-thick adipose tissue layer
-poor venous and arterial access
-laryngeal conformation
-tracheal bronchus
-small tidal volume and chest compliance
-no sweat glands
Which drug administration routes are used in pigs?
-PO
-IM
-intranasal
-intra-testicular
-intra-osseous
Which veins are used in pigs?
IV drug admin:
-external jug.
-cranial vena cava
sample blood:
-cranial vena cava
-tarsal vein
small catheters:
-caudal auricular vein
-cephalic vein
Which sedatives are used in swine?
-midazolam
-xylazine
-butorphanol
-alfaxalone
-ketamine
-tiletamine/zolazepam combo.
What are the characteristics of mask induction?
-done to pre-oxygenate, facilitate intubation, or bring pig into unconsciousness
-need a deep mask to accomodate long snout
-high flow and high vaporizer setting
Which induction agents are used in swine?
-midazolam
-alfaxalone
-ketamine
-propofol
-tiletamine/zolazepam combo.
Which challenges complicate swine intubation?
-large epiglottis
-redundant tissues in the larynx
-target is small and far, with small opening between maxilla and jaw
-obtuse angle to overcome
-prone to laryngospasm
-possible to perforate posterior floor of larynx
Which supplies are needed for swine intubation?
-long blade laryngoscope
-mouth speculum
-extended neck
-lidocaine splash
-regular or long ET tube
-soft stylet
What is the ideal ET tube position in the pig and why?
-cranial to 2nd intercostal space
-prevents tracheal bronchus exclusion and endobronchial intubation
Which injectable combinations are used to maintain swine anesthesia?
-guaifenesin/ketamine/xylazine
-telazol/xylazine/ketamine
Which injectable medications are used for PIVA?
-lidocaine
-ketamine
-fentanyl
Which inhalant medications are used to maintain swine anesthesia?
-isoflurane
-sevoflurane
-desflurane
What is important about swine MAC?
it is higher than all animals except cats for all inhalant drugs
What are the characteristics of swine positioning during anesthesia?
-done to prevent neuromyopathy
-padding used
-limbs flexed and relaxed
What is monitored during swine anesthesia?
-depth of anesthesia (jaw tone preferred)
-pulse-ox
-ECG
-blood pressure
What are the characteristics of ventilation in swine anesthesia?
-prone to hypoventilation
-mechanical ventilation recommended if available
-small animal machine set up used
Which drugs are used for blood pressure management in swine?
-dobutamine
-dopamine
-ephedrine
-phenylephrine
-vasopressin
-norepinephrine
What are the characteristics of swine temperature regulation under anesthesia?
-no hair cover; more prone to hypothermia
-cannot sweat; must avoid hyperthermia
-bair hugger and heated blanket used until animal is warm; removed before elevated temp. can begin
What is malignant hyperthermia?
-genetic, hyper-metabolic syndrome in humans and swine
-associated with PSS and PSEP syndromes
-single amino acid mutation on Ryanodine Receptor Type 1
What are the triggers for malignant hyperthermia?
-rough handling/stress
-high ambient temp.
-vigorous exercise/strain
-transportation
-inhalant drugs
-succinylcholine
What is the pathophysiology of malignant hyperthermia?
-excess of Ca efflux from sarcoplasmic reticulum
-cannot regulate efflux due to mutation
-results in over-activation of excitement-contraction coupling
-muscle contracture and release of heat occurs
-insaturation of anaerobic metabolism
What are the clinical signs of malignant hyperthermia?
-hyperthermia
-hypercarbia
-tachypnea/dyspnea
-tachycardia
-cardiac arrhythmias
-hypotension
-acid-base and electrolyte disorders
-muscle rigidity
-blanched or reddened areas of skin
-skin and mucus membrane cyanosis
-coagulopathy
-shock
-SIRS
-death
Which changes on bloodwork are consistent with malignant hyperthermia?
-hyperkalemia
-hypercalcemia
-hyperphosphatemia
-hypermagnesemia
-severe lactic acidosis
What are the treatment steps for malignant hyperthermia?
-discontinue inhalant
-change breathing circuit and rebreathing bag
-continue 100% O2 admin.
-actively cool
-dantrolene
-NaHCO3
-treat hypotension
-treat hyperkalemia
-treat arrhythmias
What is the outcome of malignant hyperthermia?
often fatal
What can be done in pigs suspected to be at risk for malignant hyperthermia?
pre-treat with dantrolene the night before and morning of anesthesia
What is the modern method for screening for malignant hyperthermia?
RYR1 qPCR-HRM assay from EDTA blood sample
What are the characteristics of swine recovery from anesthesia?
-keep IV access as long as possible
-prolonged recovery typical
-hypothermia risk
-mutilation risk if re-introduced to pen mates
-noisy breathing should be investigated immediately
What are the possible post-extubation complications in swine?
-laryngospasm
-laryngeal edema
-hematoma
-soft palate engaged in larynx
-resp. depression resulting in apnea, resp. distress, and edema
When should extubation be attempted?
when there are signs of swallowing/chewing/coughing/shivering
