Lecture 20 11/19/24 Flashcards
What are the components of brachycephalic syndrome?
-elongated soft palate
-stenotic nares
-everted laryngeal saccules
-hypoplastic trachea
What are brachycephalic dogs prone to?
-dyspnea
-respiratory complications
-aspiration pneumonia
-esophagitis
-hypertrophic gastropathy
-gastroduodenal inflammation
-ulceration
What are the anesthetic concerns with brachycephalics?
-upper airway redundant soft tissue relaxation
-dyspnea/hypoventilation
-stenotic upper airway/hypoplastic trachea
-smaller/collapsed trachea
-higher resistance to airflow
-prone to vagal response
-subclinical aspiration pneumonia
What are the preanesthetic planning steps for brachycephalic dogs?
-physical exam
-bloodwork
-chest x-ray
-avoid stress and strenuous physical restraint
-avoid heavy sedation without intubation
What are the characteristics of anticholinergics as premeds?
-prevent bradycardia
-decrease GI and resp. secretions
Which premeds are used in brachycephalics in addition to anticholinergics?
-antiemetics/prokinetics
-antacids
-steroids
-analgesics/opioids
What are the considerations that should be accounted for when inducing a brachycephalic?
-pre-oxygenate first
-have smaller than usual ET tubes available
-use ketamine/benzos or propofol/benzos
How should anesthesia be maintained in brachycephalics?
PIVA
Which local/regional anesthesia techniques are used in brachycephalics?
-line/field block
-nerve block
-epidural
Which monitoring is most important for brachycephalics?
cardiovascular and respiratory monitoring
What are the characteristics of recovery for brachycephalics?
-delayed extubation
-sternal positioning
-heliox (He + O2) has less resistance to flow
-steroids/neosynephrine
-continue with O2 support and pain control
What are the characteristics of gastric dilation volvulus?
-serious and potentially fatal
-distention and twisting
-unproductive retching
-dehydration
-pH imbalances
What are the respiratory effects of GDV?
-hypoventilation
-hypoxemia
-impaired uptake of inhalational anesthetics
What are the cardiovascular effects of GDV?
-occlusion of caudal vena cava
-reduction in venous return
-less cardiac output
-less tissue perfusion
-anaerobic respiration
-acidemia
What are the preanesthetic planning considerations for GDV patients?
-extensive homeostatic stabilization
-sternal positioning
-intensive oxygenation
-emergency decompression (stomach tube, percutaneous)
-intensive fluid therapy
Which drugs are used for GDV premedication and induction?
-drugs with minimal CV and resp effects
-opioids given slowly via IV
-ketamine/alfaxalone/etomidate/fentanyl combined with a benzo
Why is lidocaine used for PIVA in GDV cases?
-analgesic
-anti-inflammatory
-anti-arrhythmic
-ROS scavenger
-prokinetic
In addition to PIVA, how else should anesthesia be maintained/supported for GDV patients?
-assisted ventilation
-inotropic support
Which monitoring tools should be used in GDV patients?
-ECG
-BP
-EtCO2
-electrolytes
-blood gas analysis
What are the steps of pre-anesthetic care for cardiac patients?
-delay anesthesia for 2 weeks after starting a new cardiac med.
-do not discontinue cardiac meds
-obtain complete history and physical exam
-obtain chest x-rays and echo.
-lab work; focus on PCV, total protein, creatinine, UA, and electrolytes
-monitor; arterial blood pressure, ECG, pulse ox
What are the characteristics of anesthetic pre-meds in cardiac patients?
-pre-oxygenate
-no anticholinergic use
-use opioid + sedative neurolept analgesia
What are the characteristics of ketamine as an induction agent for cardiac patients?
-does not depress CV system
-anesthetic and analgesic
-used in cardiac ASA 1 and 2 cases
-titrate dose to effect
-only use in sufficiently sedated animals
-use with a muscle relaxant
Why are propofol and alfaxan not great options for induction in cardiac patients?
-CV depression: lowers CO and SVR while increasing HR
-causes apnea and resp. depression
-no analgesic properties
What are the characteristics of etomidate?
-minimal cardiopulmonary depression
-used in patients with an ASA greater than 2
-good for CHF, cardiomyopathy, and poor contractility patients
-no analgesic properties
-short anesthetic time
-use with benzos to prevent excitement, myoclonus, vomiting, and apnea
What are the characteristics of anesthetic maintenance for cardiac patients?
-use PIVA to minimize inhalant conc.
-use local/regional blocks
-minimize fluid admin.
-monitor ABP, CVP, ECG, EtCO2, and pulse ox intensively
What are the pathophysiologic changes that occur with diabetes mellitus?
-polyuria and renal dysfunction
-acid-base abnormalities
-muscle weakness
-neurologic/altered mentation
-hypoventilation/hypotension
-immunosuppression
-hepatomegaly and lipidosis
-cataracts
What are the preoperative steps for diabetes patients?
-schedule surgery first thing
-fast for less than 6 hours
-check blood glucose prior to anesthesia
-administer 1/2 the normal insulin dose
-monitor BG every 30 to 60 minutes afterwards
-administer dextrose if hypoglycemic
Why are opioids the premed of choice over alpha2s in diabetes patients?
alpha2 agonists block insulin release and cause hyperglycemia
Which medication combos are used for induction in diabetes patients?
-propofol + benzo
-ketamine + benzo
Which aspects of monitoring are most important for diabetes patients?
-cardiovascular
-resp.
-blood glucose
What are the pathologic changes that occur with Cushing’s?
-PU/PD
-dehydration
-electrolyte imbalances
-liver and kidney disease
-decreased drug metabolism
-pyometra
-diabetes
-hepatomegaly/pot-bellied abdomen
-hypoventilation
-lethargy
-muscle wasting
-weakness
-delayed recovery
How does Cushing’s impact other body systems?
-hypertension
-congestive heart failure
-lower cardiac output
-hypercoagulability
-electrolyte disturbances
-immunosuppression
How is the cardiovascular system evaluated in Cushing’s patients pre-anesthesia?
-auscultation
ECG
-blood pressure
-echo
-chest x-ray
What other pre-anesthesia steps are taken in Cushing’s patients in addition to CV system eval?
-CBC
-serum chem
-pre-oxygenation
Which premeds should be avoided in Cushing’s patients?
-alpha2s: cause hypertension
-acepromazine: longer duration of action, causes hypotension
Which premeds can be used in Cushing’s patients?
opioids; CV friendly, easily metabolized
Which medications/combos can be used to induce Cushing’s patients?
-propofol + benzo
-alfaxan
-propofol + ketamine
-ketamine + benzo
-hydromorphone or fentanyl + benzo
What are the steps of Cushing’s patient anesthesia maintenance?
-PIVA with inhalant and injectable
-ventilatory support
-multimodal analgesia
-intensive CV and resp. monitoring/support
What are the clinical signs of hypothyroidism?
-dull hair coat and hair loss
-mental dullness
-weight gain
Which concurrent conditions can complicate hypothyroidism?
-laryngeal paralysis
-megaesophagus
What are the anesthetic concerns in unregulated hypothyroidism cases?
-lower metabolic rate
-lower drug clearance
-lower temp.
-lower drug requirements
-more adverse effects
-longer recoveries
-decreased stroke volume and heart rate
-less responsive CV system
-higher risk of hypotension and bradycardia
What is the goal for premedication in hypothyroidism patients?
use drugs with shorter duration of action and repeat doses as needed
Which drugs are used as premeds in hypothyroidism patients?
-fentanyl/remifentanil
-hydromorphone
-glycopyrrolate
What are the goals of anesthesia induction in hypothyroidism patients?
-use drugs with less CV depressant effects
-use reversible drugs
Which drug combos are used to induce hypothyroidism patients?
-propofol/alfaxalone combined with ketamine or benzo
-ketamine + benzo combination
What is the goal of anesthetic maintenance in hypothyroidism patients?
use TIVA or PIVA to lower the conc. of inhalant anesthetics and reduce CV adverse effects
Which monitoring and support measures are used for hypothyroidism patients?
-ECG
-blood pressure
-capnography
-pulse ox
-temp.
-fluids
-heat support
-ventilatory and CV support
