CNS, Renal, And Hepatic Disease Flashcards
What are common Renal elective procedures?
Dental
Mass Removal
What are common Renal Non-elective procedures?
Urethral stones
renal transplant
renal tumor
What are common Renal Emergency procedures?
Feline urethral obstruction
Ruptured Bladder
What are the three main functions of the kidneys?
Filtration
Reabsorption
Secretion
How much cardiac output do the kidneys receive?
25%
What does reabsorption depend on?
Aldosterone ADH Renin-angiotensin atrial natriuretic factor prostaglandins catecholamines
What are kidneys sensitive to?
Ischemia
Hypoxia
What is the constant mean arterial pressure of the Renal blood flow?
80-180mmHg
What drugs should you avoid for the renal disease?
Anesthetics causing hypotension or requiring renal excretion
NSAIDs
What Pre-op management should happen with Renal Compromise?
Fluid diuresis
Attention to electrolyte status (including Ca and Mg) with supplementation as necessary
What Intra-op management should happen with Renal Compromise?
IV Fluids
MAP should be maintained about 70-80mmHg
What is the fluid rate for renal compromised patients?
10mg/kg/hr
What should you do first with a patient with Feline Urethral Obstruction?
Stabilize: Hyperkalemia and Hypovolemia
How do you treat Hyperkalemia in a cat with Urethral Obstruction?
Calcium gluconate
Regular Insulin + dextrose
How do you treat Hypovolemia in a cat with Urethral Obstruction?
Buffered isotonic IV fluids
What drugs do you use in Feline Urethral obstruction?
Cardiovascular-sparing drugs: Opioids and Benzos
What drugs do you avoid in Feline Urethral obstruction?
Ketamine
What is the MAP that must be maintained for normal cerebral blood flow?
50-150mmHg
What is the equation for Cerebral perfusion pressure?
MAP - ICP
Cushing Reflex
Severe Increase ICP leading to poor cerebral perfusion
Leads to sympathetic response: vasoconstriction, increased cardiac output leading to hypertension
Carotid baroreceptors sense hypertension and cause reflex bradycardia
Increased ICP causes dysfunction of respiratory center causing irregular breathing pattern
What are the preferred drugs for patients with CNS disease?
Do not increase ICP
cause seizures or lower seizure threshold
Decrease Cerebral blood flow
Acepromazine - CNS effects
decrease seizure threshold
Benzodiazepines - CNS effects
Decrease Cerebral Blood Flow and ICP
Control seizures
Opioids - CNS effects
Minimal effects on Cerebral Blood Flow and ICP
What are the side effects of Opioids?
Vomiting
hypoventilation
increase ICP
What drug is used for CRI maintenance of anesthesia in CNS disease?
Propofol
Etomidate - CNS effects
Decreases ICP, CBF< and CMRO2
Ketamine - CNS effects
Increases ICP and CBF
May cause seizures
Succinylcholine - CNS effects
Increases ICP
What are the CNS effects of inhalational anesthetics?
at greater than 1 MAC increase CBF and ICP via cerebral vasodilation
Which inhaled anesthetic has the greatest CNS effects?
Halothane
What do you do for Intracranial disease during anesthesia?
Maintain straight neck and head slightly elevated
Prevent vomiting/coughing
Prevent hyperglycemia, hypercapnia, hypoxemia
Conservative fluid recuccitation
Mannitol before induction if increased ICP is suspected
Trendelenburg-lie positioning
In horses: head down positioning in isoflurane anesthetized horses increases ICP by 80% and decreases CBF 20%
Equine intracarotid injection
causes violent behavioral reaction and seizures
How do you treat seizures from Equine Intracarotid injection?
Thiopental +/- guafenesin
Supplemental O2 and fluids
What are the functions of the Liver?
Protein metabolism Carbohydrate metabolism Fat metabolism Vitamin storage Iron storage Produces coagulation factors Immune function Metabolizes Drugs, hormones, toxins
What are the clinical signs of liver disease?
Depression anorexia weight loss Icterus ascites abnormal behavior seizures
What drugs may worsen the signs of hepatic encephalopathy?
Benzodiazepines
What are the drug considerations for Liver disease?
Liver metabolizes most anesthetic drugs so the drug action will be increased and/or prolonged
Many drugs are highly protein bound so hypoproteinemia can will cause higher blood levels
What are the pre-anesthetic considerations for Liver disease?
Optimize perfusion
Correct hypoglycemia and electrolyte disturbances
Abdominocentesis for ascites
Blood type and crossmatch
What drugs should you avoid in gallbladder disease?
Opioids
What are the preferred drugs of liver disease?
Propofol
Opioids
Alfaxalone
Etomidate
Which inhalation anesthetic increases total hepatic blood flow?
Isoflurane
What inhalation anesthetics decrease portal vein and total hepatic blood flow?
Sevoflurane
Des
Which local anesthetics are metabolized by the liver?
Lidocaine
Bupivicaine
Mepivacaine
Why is Acepromazine is contraindicated in liver disease?
Vasodilation
Decreased BP
Inhibits platelet aggregation
Why are alpha 2 agonists contraindicated in liver disease?
Decreased CO
Why are barbiturates contraindicated in liver disease?
Extensively redistributed, dependent on hepatic metabolism
Highly protein bound
Why is halothane contraindicated in liver disease?
Decreased hepatic blood flow
Metabolized by liver
Hepatopathy
Why is Succinylcholine contraindicated in liver disease?
Cholinesterases synthesized by liver
Why is Guaifenesin contraindicated in liver disease?
Metabolized in liver
Metabolite (catechol) can cause toxic neuro effects
What are the intra-op considerations for liver disease?
Maintain liver perfusion Monitor glucose Monitor hemorrhage Monitor depth of anesthesia, drug requirements may be decreased Maintain normal body temperature
What are the Post-op considerations for liver disease?
Check acid/base status, electrolytes, glucose, and pcv/tp
Maintain body temp
Monitor for neurological abnormalities
What is important for Portosystemic shunt ligation?
Arterial BP monitoring
