GI Disease Flashcards
Reperfusion of compromised tissue causes the release of??
Inflammatory mediators
—> vasodilation and hypotension, decreased inotropy, and ventricular arrhythmia
Manipulation of the GI tract can cause _________ stimulation
Vagal
—>bradycardia
What is a dilation of esophagus with poor motility ?
Megaesophagus
Can be congenital
-mechanical or neurological
Or
Acquired idiopathic (most common)
What are concerns for anesthesia in a dog with megaesopgus?
Regurgitation and aspiration
Gastroesophageal reflux
How long do you fast dogs with megaesophagus??
5ish hours, avoid prolonged fast —> gastroesophageal reflux
In dogs with megaesophagus, we want to avoid vomiting and have rapid induction/control of airway. What would be good drug choices for this?
Avoid opioids causing vomiting
Acepromazine —> antiemetic effect?
Propofol and alfaxalone good for induction
AVOID ketamine
You are doing endoscopy on a patient. What will you consider for your drug choices??
Patients may have chronic disease —> hypoproteinemia , thin BCS
Debilitated patient ? —> avoid drug with significant CV effects
Upper GI studies —> have anticholinergic on hand incase of vagal simulation causing bradycardia
Exploratory abdominal surgery is usually due to chronic GI disease requiring a full thickness biopsy. What considerations will you have prior to surgery and precautions to take during the surgery?
SAME as endoscopy + check for liver disease and clotting times
Patients may have chronic disease —> hypoproteinemia , thin BCS
Debilitated patient ? —> avoid drug with significant CV effects
Upper GI studies —> have anticholinergic on hand incase of vagal simulation causing bradycardia
If you have an emergency abdominal exploratory surgery for hemoabdomen, what is the usual emergency presentation ?
Clinical signs: weakness and collapse
Hypovolemic shock —> hypotension and tachycardia, pale mucus membranes
Hemoabdomen is usually secondary to??
Splenic neoplasia (hemangiosarcoma) or benign splenic disease
—> both require emergency splenectomy to stop hemorrhage
How are you going to resuscitate an animal with hemoabdomen prior to surgery?
Fluids - balanced replacement crystalloids (LRS, plasmalyte A, or Norm-R)
Opioid analgesia
Avoid resuscitating to normal awake BP levels —> may disrupt clots
(Doppler at 9mmHg is reasonable)
Splenic disease often causes ventricular arrhythmias, what id your drug of choice for treatment?
Lidocaine
What would you the best choice for premed in hemoabdomen case?
Opioids (short acting-> fentanyl) and benzo (midazolam) IV
May include lidocaine for arrhythmia and MAC sparing /analgesic effect
What injectables can you used to decrease the dose of inhalant anesthesia? Why would you want to do this?
Fentanyl, hydromorphone, oxymporphone
Lidocaine
Ketamine
Inhalants have significant CV effects —> hypotension
T/F: Most patients with hemoabdomen require very little inhalant anesthesia
True
ISO 0.25-1%
Sevoflurane 1-2%
What monitoring equipment do you use in a hemoabdomen case?
DIRECT BP —> more accurate and can also evaluate pulse pressure
TPR
Indirect BP
ETCO2
MAP should be maintained above _______ in hemoabdomen
60 mmHg
You have hypotension during your hemoabdomen surgery (oh no.. tragedy), what will you do to fix it?
If hypovolemia —> give fluids
If vasodilation or decreased inotropy —> DECREASE inhalant +/- CV drugs
Post op splenectomy patients are very susceptible to ventricular arrhythmias, how do you deal?
Hospitalized for 24-48 hours post op
Lidocaine CRI
Continue analgesic
What drugs do you used for a routine removal of a GI foreign body?
Opioids and benzodiazepines
Any induction drug will do
What drugs would you avoid in a routine GI foreign body surgery? What additional drug would you avoid if patients was sick/septic
Acepromazine -non reversible
Dexmedetomidine —> strong CV effects
Sick/septic : also avoid propofol (CV effects) and etomidate (adrenal suppression)
What would you use for premed and induction in a sick/septic patient with GI foreign body?
Opioid and benzo for premed, and again for induction
You are doing an emergency cholecystectomy. How sensitive will your patient be o anestheric drugs?
Very sensitive —> SICK patients (rupture causing bile peritonitis)
Likely have hypotension- vasodilation and decreased inotropy due to inflammatory mediator release
What drugs will you use during you emergency cholescytectomy??
MAC sparing techniques (opioid, benzo, ketamine, and lidocaine)
Vasopressor and inotrope for hypotension
Mortality rates with GDV are primarily dependent on ??
Degree of gastric necrosis
Serial lactate measurements have been examined ANS a prognostic indicator
GDV patient has hypovolemic shock. What is the game plan?
Give fluids
Combo replacement crystalloid and colloids
What do you give GDV patients for analgesia??
Pure mu opioid
IV hydromorphone, oxymorphone, fentanyl
The dilated and gas filled stomach in a GDV patient can cause what?
Decreased venous return —> hypovolemic shock
Pressure on diaphragm —> hypoventilation
What can you do in your GDV patient prior to induction to help BP and ventilation?
Gastric trocharizaiton
Gastric tube can be passed once airway is protected with ET tube
What drugs do you use in GDV procedure ?
CV sparing drugs (AVOID profofol or use at vEry low dose)
Routine use of lidocaine —> bolus then CRI
Opioid-benzo + low does alfaxalone/ketamine
How are you monitoring your GDV patients?
Direct BP
ECG for ventricular arrhythmias
-consider lidocaine bolus
You have intra-op hypotension in your GDV case. What do you do?
Turn down vaporizer
Add injectable for MAC sparing
Fluid bolus
Vasopressor/inotrope as needed
You have high PCV and azotemia in your equine colic patient, what is going on?
Dehydration —> give fluids LARGE volume
Crystalloids 10-20L before induction
If rushed to surgery —> 10 L of crystalloid and 1L of hypertonic saline before induction
Hyperlactatemia in your equine colic patient is a sign of??
Poor perfusion +/- GIT ischemia
In equine colic cases, there is nearly always already an A2 agonsit, NSAID, +/- butorphanol on board from referring vet. What do you do for premed and induction?
May already be sedate
If not, premed with Xylazine and butorphanol
Induce with ketamine and diazepam
What are you going to give for maintenance during equine colic surgery?
ISO/sevoflurane
Lidocaine CRI (MAC sparing and free radical scavenger)
Intermittent butorphanol for analgesia (q 1hr)
How will you monitor your equine colic patient??
TPR, ETCO2, ECG
Direct BP —> all equine patients receiving inhalant anesthesia
Arterial blood gas (q 1 hr) —> PaO2, PaCO2, lactate and iCa
What CV complication can arise from colic surgery?
Hypotension !!
Aggressive fluid therapy
Dobutamine, ephedrine, NE, dopamine, vasopressin
Ca gluconate (hypocalcemia causing poor contractility)
** hypotension can get significantly worse at time of reperfusion of ischemic gut—> inflammatory mediators***
Hypoxemia is a common complication in equine surgery. What do you do?
High peak inspiration pressure to pen alveoli and decrease V/Q mismatch
Consider PEEP and recruitment maneuvers
What is permissive hypercapnia?
PaCO2 can be tolerated up to 60-70mmHg
—> sympathetic stimulators effect
—> deceased negative effects of IPPV on cardiac output
What are the complications for recovery in equine colic cases?
Exhausted from long colic and travel
Poor tissue O2 delivery during surgery/anesthetics —> poor muscle function
Hypocalcemia and hypokalemia —> muscle weakness
