Exam 2: Feline Anesthesia

what are the two essential safety features for equipment in cats

• circut manometer that allows delivery of manual breaths

• pop off relief valves to prevent excessive airway pressures and potential barotrauma due to small lung capacity

what other safety concerns need to be addressed with anesthesia equipment in cats

• NRCs frequently used as they often offer less resistance

• rebreathing CO2 prevented with high oxygen flow rates

• non-rebreathing circuits should be used in cats <3kg

• oxygen flush valve should never be used when a cat is connected

• if you must use rebreathing, pediatric hoses are needed

how is dead space minimized with cats

• important for capnograph, want less than 2-3mL/kg

• remove elbow adaptors

how is history taking before cat anesthesia described

• cats dont show obvious signs in early stages of disease

• owners often unaware about cats being overweight

what is the the recommended drug for reducing fear response in cats

gabapentin 50-100mg PO

what are tips for managing very anxious or stressed cats

• planning the visit previously for days less busy at the clinic

• administration of gabapentin the night before

• have owner bring familiar bedding or toy

• use a synthetic feline facial phheromone

• remain calm cat wards

how is preanesthetic lab testing described in cats

• stress may alter results including glucose value

• annual testing for hyperthyroid is recommended at 7-10 yrs old

what are common comorbidities in cats

• hypertrophic cardiomyopathy

• hyperthyroidism

• renal diseases

• DM

• asthma or lower airway disease

• obesity

• degenerative joint disease

• urinary obstruction

what is hypertrophic cardiomyopathy

• high incidence in cats >7 yrs

• use of A2 agonists remain controversial- may decrease CO

• good option is to use alfaxalone with butorphanol

what drugs am I using in cats with HCM

• alfaxalone 2mg/kg

• butorphanol 0.2mg/kg IM

what is hyperthyroidism

• most common endocrinopathy in cats

• increases metabolic rate, high glucose, greater CO2, production, rapid metabolism of the drugs

• hypertension and tachycardia

• ideally a euthyroid state is desirable prior to an elective anethesia procedure
  -with antithyroid meds 2-3 weeks pre, check renal function

how is renal disease described in cats

• Iv fluid therapy 3ml/kg - cats overload quickly

• proactive monitoring and management of BP

how is obesity described in cats

• cats weighing more than 6kg 3x more likely to die due to impaired ventilation

• pre-oxygenation can assist in lengthening the time to desaturation, make sure to monitor recovery

what is urinary obstruction

• goal is to restore urine flow and correct dehydration/electrolytes

• prone to hyperkalemia

• electrocardiographic changes

• cat needs to be stabilized = calcium glyconate, insulin +dextrose

what are the two approaches recommended for procedural sedation

• sedative drugs such as dexmedetomine with opioid

• incorporate an anesthetic such as ketamine

• cats should always be monitored

how is acepromazine used as premed in cats

• inconsistent

• can make intraoperative hypotension difficult to treat

• reccomended 0.01-0.05mg/kg

• should not be used when hypotension or dehyration is suspected

how are bensodiazepines described as premeds in cats

• not suitable alone or with opioids

• unreliable outcomes

• good option in sick or old

how are a2 agonists used as premeds in cats

• dexmedetomidine widely used

• reliable dose dependent sedation

• cardiovascular effects include vasoconstriction and decreased HR and CO, increased systemic vascular resistance

in cats as premeds, anticholinergics should not be used with ? due to vomiting

a2- agonists

what is an appropriate dose of alfaxolone for premed in cats

2mg/kg IM

how is induction described in cats

• all induction drugs may cause significant respiratory depression and preoxyenation should be standard

• chamber inductions should never be routine due to severe depression of CV

what are your iinduction options for cats

• ketamine + midazolam

• telozol

• thiopenntal

• propofol

• alfaxalone (often + midazolam)

• etomidate

how are inhalants used for maintenance in cats

• doses are higher

• iso and sevo have profound effect on CV via CO and BP decreasing up to 70%

• opioid CRIs and ketamine decrease anesthetic requirements

how are TIVAs used for maintenance in cats

• propofol and alfaxalone

• propofol may prolong recovery

• alfaxolone recovery may have hyperesthesia

how should the airway be managed in cats

• airway is small and delicate

• larynx is susceptibel to spasm and prone to damaging

• tracheal tears reported

• most adult cats require 3.5-5mm ET and should be measured before intubation

• 0.2mL lidocaine topical reduces spasms

how is hypotension described as a perioperative complication

• SAP <90 or MAP <60

• first approach is to decrease inhalants

• if blood pressure remains low, fluid bolus 3-10mL/kg over to mins (contraindicated with cardiomyopathy)

• if also bradycardic, consider anticholinergics

• if persistent, dopamine CRI is recommended

how is hypothermia described as perioperative complicatios

• cats are more susceptible due to high surface area to body mass ratio

• shivering during recovery increases O2 consumption and discomfort

• heat is mainly lost through radiation, increase room temp or surround the cat with warmth

• monitor temp in recovery

how is hyperthermia described as perioperative complication

• cats may present after use of opioids, but is no reason to withhold

• supportive treatment, acepromazine may help

• temp will return in a matter of hours

how are cardiac arrythmias described as perioperative complications

• overall uncommon

• synchronous Av dissociation most common typically caused by sinus bradycardia - no treatment if BP good

• bundle branch blocks can be ID in pt with cardiac disease

how should recovery be handled in cats

• maintain for firsth 3 hrs

• consider expression bladder if full

• capnograph should be kept until extubated

• delaed recovery, dysphroria, emergence delirium common

• consider reveral agents

• if cat doesnt calm down from emergence delirum, small dose of dexmedetomidine

• patient should be warm and comfortable