Term
| How much of the total body water is located within the extracellular fluid space? |
|
Definition
1/3 to 1/2 total body water
** ECF includes the intravascular space (25% of the ECF is plasma volume, 75% is interstitial) |
|
|
Term
| How much of the total body water is located within the intracellular fluid space? |
|
Definition
| 1/2 to 2/3 total body water |
|
|
Term
| How much of the body is water? |
|
Definition
| 60% (~534-660 ml/kg in normal dogs) |
|
|
Term
| How can you calculate extracellular fluid volume? |
|
Definition
|
|
Term
| What are five mechanisms through which the body can loose water? |
|
Definition
| urine, feces, cutaneous (ex. panting), respiratory (responsible for 1/2 to 1/3 of daily water losses), third space (ex. pleural or peritoneal effusions, edema) |
|
|
Term
| What are five indications for fluid therapy in small animals? |
|
Definition
1. correct or prevent dehydration
2. correct hypovolemia
3. maintain effective circulating volume during anesthesia (b/c inhalents --> vasodilation and hypotension)
4. colloital oncotic support
5. induce/promote diuresis |
|
|
Term
| What three elements MUST be considered when formulating a basic plan for fluid therapy? |
|
Definition
Replacement
Maintenance
Ongoing lossess (ie. active losses occurring during ex. vomiting and diarrhea) |
|
|
Term
| How do you determine the replacement fluid volume that a patient needs? |
|
Definition
based on physical exam (estimate the percent dehydration), history of losses and laboratory assessments (PCV/TP, prerenal azotemia, serum osmolarity)
--> percent dehydration
replacement volume = (% deficit) x (BW) x (1000ml/kg)
**** NOT for SHOCK patients <- fluid therapy is dosed to effect, not by volume |
|
|
Term
| What should your fluid therapy plan be for a patient that is in shock? |
|
Definition
| provide 1 blood volume (dogs 8-9% BW; cats 6-7% BW) per hour until positive response is appreciable |
|
|
Term
| Where should you assess skin turgor in small animal patients? |
|
Definition
always assess skin turgor in standing patients over the back (NOT the nape of the neck)
**** young animals and obese animals may have relatively good skin turgor despite clinical dehydration |
|
|
Term
| What is the smallest amount of dehydration that is clinically detectable? |
|
Definition
| 5% <- presents as subtle loss of skin elasticity |
|
|
Term
| What equation can be used to calculate the replacement volume |
|
Definition
| replacement volume = (% deficit) x (BW) x (1000ml/kg) |
|
|
Term
| What is a general guideline for determining the type of fluid to be used for replacement therapy? |
|
Definition
try to use a fluid that simulates what was lost
ex. sweat and GI secretions are isotonic, respiratory secretions are hypotonic (just free water) and urine can be hypo to hypertonic depending on specific gravity |
|
|
Term
| What is the difference between crystalloid and colloid fluids? |
|
Definition
crystalloids are fluids composed of water and small molecular weight substances that disseminate between ECF and ICF depending on osmolarity of the different compartments.
Colloids are solutions that contain substances of large molecular weight that are reserved within the vasculature and act to increase oncotic pressure within this system |
|
|
Term
| What is normal plasma osmolality? |
|
Definition
~290 mmol/L
so hypertonic fluids >300 mmol/L and hypotonic fluids are <300 mmol/L |
|
|
Term
| What are some of the benefits of using isotonic fluids? |
|
Definition
| can safely give large volumes rapidly, ideal for parentral route of administration |
|
|
Term
| When is hypertonic fluid administration indicated and how should it be delivered? |
|
Definition
usually used to manage shock (increases concentration of solutes in the vasculature --> increased osmotic pressure draws water into the vasculature to help maintain blood pressure)
ideally should be delivered via central line as may cause phlebitis when administered via peripheral vein |
|
|
Term
| When in doubt what two types of fluid are most likely safe options? |
|
Definition
| 0.9% saline and LRS <-- both are isotonic |
|
|
Term
| What is the maximum rate at which small animal patients can safely receive fluid? |
|
Definition
1 blood volume /hour
8-9% BW in dogs; 6-7% BW in cats |
|
|
Term
| What general guidelines should be used when determining the rate of fluid administration? |
|
Definition
rate at which fluids are administered should mirror the rate at which the patient developed the fluid deficit
caveats:
*** an in the case of large electrolyte and acid-based abnormalities replacement should be slow
*** in the case of pre-renal azotemia replacement should be rapid |
|
|
Term
| What are some benefits associated with using the oral route of fluid administration? |
|
Definition
| can administer very hypertonic solutions rapidly with minimal side effects, most physiologic route of fluid administration |
|
|
Term
| What are some disadvantages of oral fluid administration? |
|
Definition
| inadequate replacement for patients with acute or extensive losses, cannot be used when patient must be NPO or in diseases associated with inadequate GI absorption |
|
|
Term
| What are some advantages and disadvantages to administering fluids SQ? |
|
Definition
convenient (esp. for owners to do) and volume overload is unlikely due to gradual absorption of administered fluids
NOT adequate for patients with acute or severe losses and poor absorption in hypothermic and severely dehydrated patients (due to peripheral vasoconstriction), only small volumes of fluid can be administered, can only use isotonic non-irritating solutions <-- risk of SQ infections and sterile abscesses |
|
|
Term
| What are some advantages and disadvantages associated with IV fluid administration? |
|
Definition
allows for precise dosage and rapid replacement of fluid, if giving non-isotonic solution use a central line (to avoid phlebitis)
requires increased monitoring, catheter placement, and increased risk of overhydration |
|
|
Term
| In what patients is intraosseous fluid administration considered? |
|
Definition
very small, very young, or patients with severe vascular collapse
*** cannot administer large volumes |
|
|
Term
| What is the maintenance fluid volume in small animal patients? |
|
Definition
40 (big dogs) - 60 (cats and small dogs) ml/kg/day
*** remember, 2/3 of these daily losses are electrolyte free water (respiratory, fecal, cutaneous) |
|
|
Term
| What parameters should be monitored in ALL patients receiving fluid therapy? |
|
Definition
body weight q 12hrs (important to get baseline BW prior to initiating fluid therapy)
PCV/TP q 24 hrs
reasses hydration and any edema formation (distal limb or pulmonary) via PE +/- urine production rate and central venous pressure |
|
|
Term
| What physiologic homeostatic mediators participate in the compensatory stage of shock? |
|
Definition
| catecholamines, aldosterone, cortisol, ADH, and activation of renin-angiotensin |
|
|
Term
| Why should you use a dry (ie. not flushed) catheter in a shock patient? |
|
Definition
| Can use the blood that backflows into the hub of the catheter for PCV/TP and other diagnostics |
|
|
Term
| What catheter characterisitics are ideal for treatment of a shock patient? |
|
Definition
| large bore and shorter length --> faster flow |
|
|
Term
| What is the traditional "shock dose of fluids in a dog, in a cat? How should this value be applied to the actual patient? |
|
Definition
90ml/kg for dogs, 40ml/kg for cats
Shock patients should be dosed to EFFECT, divide the shock dose into 3 or so boluses to be given over 10-20min and the REASSESS (usually entire shock dose is NOT needed) |
|
|
Term
| What three crystalloid fluids are isotonic? |
|
Definition
| plasmalyte/normosol, LRS, 0.9% NaCl |
|
|
Term
| T/F you should NEVER bolus fluids that have been supplemented with potassium |
|
Definition
TRUE
----> cardiac arrest
** ideally do not add more than 0.5 mEq/kg/hr of potassium to a fluid regiment |
|
|
Term
| T/F the effects of hypteronic crystalloids in drawing fluid into the vasculature are short lived |
|
Definition
TRUE (effects last for around 30 min)
*** colloids have a more prolonged effect because the larger molecular weight particles cannot redistribute outside of the vasculature |
|
|
Term
| Colloids and hyptertonic crystalloids are contraindicated in patients with what two conditions? |
|
Definition
dehydration and heart disease
** these fluids draw water out of the interstitium (further contributing to dehydration) and increase the circulating blood volume (volume overload-->CHF in patients with compromised cardiac function) |
|
|
Term
| T/F packed RBC are not a potent colloid |
|
Definition
TRUE
*** oxyglobin has both colloid and oxygen carrying capacity, but is intermittently available and very EXPENSIVE |
|
|
Term
| What is the major indication for use of hypertonic saline in small animals? |
|
Definition
head trauma (esp. if presenting w/ epistaxis, abnormal PLR, anisocoria) --> hypertonic solutions will draw fluid out of the surrounding interstitium and can minimize cerebral edema
**also administer a colloid (to ensure adequate blood volume for a longer duration) |
|
|
Term
| If your shocky patient is not responding to appropriate intravascular volume resuscitation how can you confirm adequate volume expansion prior to giving circulatory drugs (ie. positive ionotropes and vasoconstrictors)? |
|
Definition
Measure central venous pressure!
*** lack of response to volume resuscitation is associated with poorer prognosis |
|
|
Term
| What three drugs can be used to maintain cardiac output and blood pressure in a shock patient that is not responding to appropriate intravascular volume resuscitation? |
|
Definition
dobutamine (increase cardiac output)
dopamine (vasoconstriction)
epinephrine (tx persistent hypotension when dobutamine/dopamine are not effective)
**** these drugs should be administered as a CRI due to short half lives |
|
|
Term
| What seven parameters should be assessed every 10/15 minutes in a shock patient? |
|
Definition
rectal temp, HR, RR, pulse quality, MM color, CRT, level of consciousness
*** remember trends determined by serial measurements are the most valuable tool for patient assessment |
|
|
Term
| What is the most accurate method of measuring blood pressure? |
|
Definition
via arterial line
** usually gain access to the arterial system via dorsal pedal or femoral artery |
|
|
Term
| T/F indirect blood pressure monitoring via doppler or Dinamap unit measures systolic and mean blood pressure respectively |
|
Definition
TRUE
doppler --> systolic
Dinamp --> mean |
|
|
Term
| How can you measure central venous pressure in small animal patients? |
|
Definition
use a jugular catheter (ideal is to place tip of the catheter through the cranial vena cava to the level of the right atrium) and a water manometer
*** remember CVP is a reflection of preload, if CVP is normal but blood pressure is low this demonstrates failure of the myocardial pump and is an indication for using dobutamine/dopamine +/- epinephrine to tx cardiogenic shock) |
|
|
Term
| T/F DO NOT use steroids on shock patients |
|
Definition
|
|
Term
| What clinical signs are often associated with oropharyngeal dysphagias in small animals? |
|
Definition
| hypersalivation, gagging, excessive mandibular/head motions, dropping food, nasal discharge |
|
|
Term
| What are some of the differences between anatomic and functional oropharyngeal dysphagias? |
|
Definition
Most functional disorders are due to failure or incoordination of muscular contractions secondary to neuromuscular disease
Anatomic disorders physically impede material from passing through the oropharynx and include strictures, FB, neoplastic, traumatic and inflammatory processes |
|
|
Term
| What tests are useful for the diagnosis of morphological/anatomic oropharyngeal dysphagia? |
|
Definition
videofluoroscopy, medical imagining (survey/contrast radiography, ultrasound, MRI) +/- tissue biopsy with histopath and culture if inflammatory or neoplastic processes are suspected
** videofluoroscopy is the dx test of choice for ALL suspected oropharyngeal disphagias |
|
|
Term
| In addition to medical imaging, what tests may be necessary to diagnose functional oropharyngeal dysphagias? |
|
Definition
videofluoroscopy +/- electrophysiology can be useful for identifying dynamic abnormalities associated with functional oropharyngeal disorders
also thyroid function panel |
|
|
Term
| When is surgical treatment of oropharyngeal dysphagia warranted? |
|
Definition
generally only used to treat cricopharyngeal achalasia (ie. cricopharyngeal myotomy)
***cricopharyngeal myotomy does not have any positive effect on oral and pharyngeal stage dysphagias |
|
|
Term
| What general supportive care can be used to treat oropharyngeal dysphagias? |
|
Definition
provide nutritional support via G tube (temporary or permanent)
if myasthenia gravis --> acetylcholinesterase inhibitors and glucocorticoids <-- often recovers spontaneously in dogs without tx
if hypothyroid --> hormone replacement therapy
*** elevated and liquid feedings have limited clinical benefit in the case of oropharyngeal dysphagia |
|
|
Term
| What is the general prognosis for oropharyngeal dysphagia in dogs? |
|
Definition
generally poor
*** only those associated with polymyositis, myasthenia gravis and hypothyroidism reliably improve with therapy |
|
|
Term
| What is the pathogenesis of cricopharyngeal achalasia? |
|
Definition
in young dogs,
etiology/pathogenesis is unknown
*** hypertension of the cranial esophageal sphincter and inadequate relaxation of the sphincter with swallowing -> progressive dysphagia and regurgitation soon after weaning, aspiration pneumonia is a common sequela |
|
|
Term
| What is the treatment of choice for cricopharyngeal achalasia? |
|
Definition
|
|
Term
| What is the physiology of primary and secondary peristalsis? |
|
Definition
swallowing initiates a wave a contractions in the esophagus (primary peristalsis)
Intralumenal distention caused by food moving through the esophagus stimulates a secondary wave of contractions (secondary peristalsis) |
|
|
Term
| What is the normal physiologic resting pressure of the cranial and caudal esophageal sphincters? |
|
Definition
Normal resting pressure is high to prevent retrograde movement of food and chyme from the stomach into the distal esophagus.
*** swallowing reflexively relaxes the cranial esophageal sphincter and initiates a wave of primary peristaltic contractions down the esophagus |
|
|
Term
| What clinical signs are associated with esophageal disease? |
|
Definition
| REGURGITATION (passive, undigested), also odynophagia, dysphagia, hypersalivation, changes in appetite and signs associated with aspiration pneumonia (coughing/dyspnea) |
|
|
Term
| What anatomic difference can be used to distinguish between the feline and canine esophagus? |
|
Definition
feline- distal 1/3 to 1/2 of the esophageal body is composed of smooth muscle
canine- entire esophageal body is composed of striated muscle |
|
|
Term
| What are the two most important pathogenic mechanisms involved in esophageal stricture formation in small animals? |
|
Definition
| fibrosis and mass compression (ex. large thyroid carcinoma compressing the lumen of the esophagus) |
|
|
Term
| What drug is associated with eophagitis and stricture formation in cats? |
|
Definition
|
|
Term
| What are four important etiologies for esophageal stricture formation in small animals? |
|
Definition
| chemical injury from swallowed substances, FB, esophageal surgery, intra/extralumina mass lesions, poor management during anesthesia (increased risk of gastroesophageal reflux -> esophagitis -> stricture formation) |
|
|
Term
| What is the best treatment for esophageal stricture? |
|
Definition
Mechanical dilation
***balloon catheters are safer and more effective than bougienage tubes. Multiple re-dilations (4x on average) at 1-2 week intervals may be necessary to achieve adequate esophageal function |
|
|
Term
| How should patients with severe esophageal stricture be provided nutrition? |
|
Definition
if stricture is severe NPO, temporary gastrotomy tube is indicated
once oral feeding have been re-instituted nutrition should be provided in a liquid form |
|
|
Term
| What are some other medical therapies that can be used in conjunction with balloon dilation, in the management of esophageal stricture? |
|
Definition
anti-inflammatory doses of corticosteroids (to prevent fibrosis. Be judicious in the presence of surgical incisions and wounds as steroids reduce expediency of healing)
if concurrent esophagitis -> mucosal protectants (sucralfate suspension PO) and gastric acid secretory inhibitors should also be provided |
|
|
Term
| What are four congenital disorders of the esophagus that occur in small animal patients? |
|
Definition
Sliding hiatal hernia (abdominal segment of esophagus + parts of the stomach are displaced cranially through the esophageal hiatus of the diaphragm)
esophageal fistula
esophageal diverticula
idiopathic megaesophagus
vascular ring anomalies
*** with the exception of vascular ring anomalies all of these disorders have an acquired form as well |
|
|
Term
| What are the four main components of treatment for esophagitis? |
|
Definition
1.Sucralfate suspension PO
2. NPO (2-3 days if mild, if severe hospitalization with enteral/parentral nutrition may be necessary)
3. gastric acid secretory inhibitors (if gastro-esophageal reflux is suspected, NEVER adequate as sole tx for esophagitis)
4. Broad spectrum antibiotics (if esophagitis is severe <- compromised mucosal barrier function, or if aspiration pneumonia is concurrent/impending) |
|
|
Term
| T/F most cases of hiatal hernia require surgical management in the form of diaphragmatic crucral apposition, esophagopexy, and gastropexy |
|
Definition
FALSE
congenital hiatal herniae (sliding is most common) often do require the above surgery; however, most acquired herniae are ASYMPTOMATIC or respond well to conservative medical management |
|
|
Term
| What three principles and medical therapies can be used to treat symptomatic hiatal herniae? |
|
Definition
reduce gastric acid secretion (H2 antagonists, PPIs)
mucosal protection (sucralfate suspension)
increase tone of caudal esophageal sphincter (metoclopramide, erythromycin) |
|
|
Term
| What is the most common etiology of megaesophagus in dogs? |
|
Definition
|
|
Term
| What are some diseases/pathologies associated with acquired secondary megaesophagus in dogs? |
|
Definition
Myasthenia gravis (25-30% of cases, often present with concurrent peripheral muscle weakness)
hypoadrenocorticism, lead poisoning, lupus myositis, severe esophagitis +/- hypothyroidism |
|
|
Term
| What is the treatment for megaesophagus secondary to myasthenia gravis? |
|
Definition
pyridostigmine (cholinesterase inhibitor -> increases the amount of acetylcholine at the motor endplate to enhance neurotransmission and muscle contractions)
once clinical improvement use immunosuppresive doses of corticosteroids or azathioprine |
|
|
Term
| What is the aim of therapy for acquired idiopathic megaesophagus in dogs? |
|
Definition
nutritional management and treatment of aspiration pneumonia
high calorie diet, small frequent feeding, elevated/upright to enhance gravitational drainage through the hypomotile esophagus, solid or liquid consistency depending on patient preference
monitor for respiratory disease, trans/endotracheal wash or BAL should be used for culture if pulmonary infections are suspected
*** bethanechol can stimulate some esophageal contractility (remember dogs have an entirely striated esophagus so metaclopramide and cisapride will not enhance motility) but contractions are poorly coordinated which reduced physiologic effectiveness
*** high incidence of concurrent esophagitis <-- tx with sucralfate suspension |
|
|
Term
| What parasite is associated with esophageal neoplasia in dogs? |
|
Definition
| spirocerca lupi --> form inflammatory granulomas during esophageal migration --> metaplastic/neoplastic transformation --> fibro/osteosarcomas |
|
|
Term
| What is the most common primary esophageal tumor in cats? |
|
Definition
squamous cell carcinoma
*** fibro/osteosarcoma is most common in dogs, often associated with spirocirca lupi infection |
|
|
Term
| What is the most useful modality for diagnosis of esophageal neoplasia? |
|
Definition
imaging
survey rads and thoracic ultrasound for periesophageal tumors
barium contrast studies are often necessary for intramural/luminal lesions, as well as endoscopy with mucosal biopsies |
|
|
Term
| What are some challenges associated with treatment of esophageal neoplasia? |
|
Definition
surgical resection is complicated by the tendency of the esophagus to form strictures, and the necessity for lengthy resections with high tension on anastamosis <-- dehisence
radiation therapy is complicated by sensitive mediastinal structures that lie in close proximity to the esophagus
chemotherapy is not effective against all esophageal neoplasms, but should be considered esp. in cases of lymphoma |
|
|
Term
| What clinical signs are associated with delayed gastric emptying and mechanical gastric outflow obstruction? |
|
Definition
|
|
Term
| What is the etiology associated with delayed gastric emptying? |
|
Definition
secondary to GDV (shearing of muscle fibers + damage to myenteric plexus)
secondary to infectious or inflammatory gastric dz, radiation therapy, ulcers, electrolyte disturbances (Ca, K, Mg), matabolic disorders (addison's, uremia, DM), and drug effects (anti-cholinergics)
*** IE. Tons of shit causes it, you have to do extensive diagnostic work up |
|
|
Term
| What is the etiology underlying gastric outflow obstruction? |
|
Definition
MECHANICAL obstruction in the region of the pylorus and adjacent doudenal segment
**** Diagnosis is straightforward -> imaging (radiology, ultrasound, endoscopy)
Treatment of choice is surgery |
|
|
Term
| What is the therapy of choice for a dog with gastric outflow obstruction? |
|
Definition
SURGERY
ex. removal of foreign body, surgical resection (inflammatory and neoplastic diseases) |
|
|
Term
| Gastric prokinetic drugs are contraindicated in the treatment of which class of GI diseases? |
|
Definition
| Mechanical gastric outflow obstructions --> could lead to perforation |
|
|
Term
| What therapy should always be included in the treatment of gastric motility disorders? |
|
Definition
Dietary management
**liquids and carbohydrates are emptied more rapidly than solid and proteins/lipids |
|
|
Term
| What are the ideal characteristics for a diet used in the treatment of gastric motility disorders? |
|
Definition
liquid to semi-liquid, low in proteins and fats, fed at frequent intervals, also low acidity and warm temp
**liquids and carbohydrates are emptied more rapidly than solid and proteins/lipids |
|
|
Term
| T/F Dogs and cats utilize different mechanisms for transfering water from a horizontal surface to their esophagus |
|
Definition
FALSE
both dogs and cats lap using the adhesion of water to the tip of the tongue with subsequent tight contact of the tongue to the roof of the mouth where the rugae of the hard palate trap the liquid until there is sufficient volume to be swallowed |
|
|
Term
| Why can dogs and cats not suck water up from a horizontal surface? |
|
Definition
dogs and cats have incomplete cheeks
***vs. pigs, sheep, horses which have complete cheeks |
|
|
Term
| How many lapping cycles are necessary for a dog or cat to transfer an aliquot (a tongue-full essentially) of water from the horizontal surface to the back of the throat? |
|
Definition
3 lapping cycles
1st is trapped between rugea of the hard palate and moves further caudal in the mouth with each new excursion of the tongue |
|
|
Term
| What region of the stomach is relatively avascular? |
|
Definition
| midway between greater curvature (left gastroepiploic artery) and lesser curvature (left gastric artery) and equidistant from the pylorus and tha cardia |
|
|
Term
| What layer of the gastric wall is the holding layer? |
|
Definition
|
|
Term
| What are the layers of the gastric wall? |
|
Definition
| serosal, muscularis, submucosal, mucosal |
|
|
Term
| What suture pattern is used for the one-layer technique in gastric surgery? |
|
Definition
| simple interrupted, ensure bites engage all layers of the gastric wall (serosal, muscularis, submucosal, mucosal) |
|
|
Term
| What diseases resulting in gastric outflow obstruction are treated with surgery in small animal patients? |
|
Definition
chronic pyloric foreign bodies (MOST COMMON)
antral pyloric hypertrophy (congenital: brachycephalic dogs, siamese cats/acquired: male small breed dogs)
gastric neoplasia (adenocarcinoma in dogs, lymphoma in cats)
Phycomycosis (granulometous fungal dz, more common in southern US)
Eosinophilic granuloma |
|
|
Term
| What laboratory findings are consistent with gastric outflow obstruction? |
|
Definition
dehydration -> prerenal azotemia
hypochloremic metabolic alkalosis (secondary to chronic vomiting)--> progressing to acidosis (lactic secondary to dehydration and hypoperfusion) |
|
|
Term
| How can you minimize the anesthetic risk of surgical patients with gastric outflow obstruction? |
|
Definition
| correct electrolyte (hypochloremia),acid base abnormalities, and prerenal azotemia prior to surgery |
|
|
Term
| What is the least invasive method of relieving gastric outflow obstruction, especially for congenital pyloric antral hypertrophy? |
|
Definition
fredet-ramstedt pyloromotomy
**incise the serosal surface of the stomach down to the mucosal layer <-- may result in fibrosis and stricture following healing, and cannot obtain full thickness biopsies (r/o neoplastic or fungal lesions) |
|
|
Term
| What two surgical techniques are good options for obtaining full thickness gastric mucosal biopsies, or for resecting lesions affecting gastric outflow? |
|
Definition
Heineke-Mikulicz pyloroplasty (full thickness longitudinal incision closed transversely)
Y-U antral advancement flap pyloroplasty (greatest increase in pyloric outflow diameter with preservation of pyloric motility) |
|
|
Term
| In the event of extensive pyloric or gastric disease, which surgical technique can be used to bypass the obstruction? |
|
Definition
Billroth
I <- pylorectomy + gastroduodenostomy
II (when extensive resection including the proximal duoudenum is required) <- pylorectomy + gastrojejunostomy (rather than creating excessive tension trying to anastamose distal duodenum to the stomach) |
|
|
Term
| What are six complications associated with billroth procedures? |
|
Definition
dehiscence or leakage -> peritonitis
pancreatitis (secondary to manipulation)
common bile duct obstruction (secondary to inflammation, edema, or fibrosis)
persistent postoperative outflow obstruction (secondary to incomplete surgical treatment of the primary
disorder)
jejunal ulceration (esp. Billroth II, gastrojejunostomy)
duodenal reflux (secondary to loss of pyloric sphincter following extensive resection) |
|
|
Term
| What region of the stomach can harbor chronic foreign bodies that do not cause any vomiting? |
|
Definition
fundus
** FB only trigger vomiting when located in the pyloric antrum, this is why gastric FB can present with both acute and chronic signs of GI obstruction |
|
|
Term
| It is contraindicated to induce vomiting in a patient where ingested foreign body had what characterisitics? |
|
Definition
|
|
Term
| What surgical technique is used to enter the lumen of the stomach? |
|
Definition
first incise the serosal/muscularis layers, then perforate the mucosa with a stab incision and extend the opening with scissors
*** make sure the incision is large enough to remove the foreign body without tearing*** |
|
|
Term
| What is the preferred suture pattern for closing the stomach? |
|
Definition
two layer closure (this minimizes the amount of mucosa that gets trapped in the incision and we don't need to worry about stricture formation because the stomach is very accommodating)
** simple continuous through all four layers followed by either simple interrupted or continuous lembert/cushing/mattress sutures |
|
|
Term
| What are two complications associated with FB removal/gastrotomy? |
|
Definition
delayed gastric emptying (secondary to prolonged pyloric irritation from chronic FB)
peritonitis (leakage or dehisence) |
|
|
Term
| What is the ideal way to diagnose upper GI bleeding? |
|
Definition
| endoscopy with mucosal biopsies |
|
|
Term
| What clinical signs and laboratory findings are consistent with upper GI bleeding? |
|
Definition
| hematamesis, melena, chronic vomiting, weight loss with microcytic hypochromic anemia |
|
|
Term
| What anatomic structure will be the first thing seen upon entering the abdominal cavity when performing emergency surgery for GDV? |
|
Definition
the ventral leaf of the omentum
***attaches to the greater curvature of the stomach and ends up laying on the ventral surface of the dilated and rotated stomach |
|
|
Term
| Obstruction of which major vessels over the course of GDV results in hypovolemic shock in these patients? |
|
Definition
| caudal vena cava and the portal vein are mechanically obstructed by distention and rotation of the stomach |
|
|
Term
| What is the typical presentation of a GDV case? |
|
Definition
| middle age to older large deep chested breed male dogs with acute onset abdominal pain and distention |
|
|
Term
| What three postulated risk factors have been shown not to correlate with development of GDV? |
|
Definition
-drinking large volumes of water immediately before or after eating increases risk of developing GDV
-raising the height of food bowls reduces the incidence of GDV
-exercising before or after eating increases the risk of GDV |
|
|
Term
| What laboratory value can be used to estimate the degree of gastric necrosis prior to doing surgery for GDV? |
|
Definition
plasma lactate
**** although this is an accurate predictor of gastric necrosis NEVER euthanize an animal based on this value alone |
|
|
Term
| T/F the development of cardiac arrhythmias is a poor prognostic indicator for patients with GDV |
|
Definition
FALSE
no statistical correlation has been shown between development of arrhythmias and outcome of dogs with GDV |
|
|
Term
| what two surgical procedures were associated with poorer prognosis following GDV surgery? |
|
Definition
partial gastrectomy (ie. removal of necrotic regions of the stomach)
splenectomy (due to extensive congestion and ischemia) |
|
|
Term
| What radiographic view is required to diagnose GDV? |
|
Definition
| Right lateral view --> double bubble (aka popeye's arm/compartmentalization) of the stomach +/- free abdominal air (indicates gastric rupture) |
|
|
Term
| T/F gastropexy will prevent future episodes of bloat |
|
Definition
FALSE
**** gastropexy only prevents volvulus |
|
|
Term
| What is the only gastropexy technique that enters the lumen of the stomach? |
|
Definition
|
|
Term
| What is the fastest and easiest gastropexy to perform in dogs being treated for or at risk of developing GDV? |
|
Definition
|
|
Term
| What is the mechanism of action of metaclopramide? |
|
Definition
| pheripheral (prokinetic) and central (antiemetic) dopamine (D2) receptor antagonists |
|
|
Term
| Which class of drugs have the most potent prokinetic effect on the GI system? |
|
Definition
serotonergic (5-HT4)agonists
ex. cisapride |
|
|
Term
| At what doses are motilin-like drugs (ex. erythromycin) effective as gastric prokinetic agents? |
|
Definition
| erythromycin stimulates migrating motility complexes and antegrade peristalsis at low, microbially-ineffective doses |
|
|
Term
| What is the mechanism of action of ranitidine and nizatidine in stimulating gastric motility? |
|
Definition
both are histamine (H2) receptor antagonists --> inhibition of acetylcholinesterase
*** effects of these drugs are most potent in the proximal GI tract |
|
|
Term
| What cholinomimetic drug stimulates motility throughout the entire GI tract? |
|
Definition
| bethanechol (binds to muscarinc cholinergic receptors) |
|
|
Term
| What anesthetic drugs should you avoid in shocky patients? |
|
Definition
acepromazine (hypotension, long duration)
alpha 2 agonists (vomiting, bradyarythmias -> decreased CO) |
|
|
Term
| What anesthetic drugs are good to use in shocky patients? |
|
Definition
| opioids (minimal CV effects) |
|
|
Term
| How can mechanical ventilation further contribute to poor tissue perfusion in patients having surgery for acute GI disease? |
|
Definition
| mechanical ventilation increases positive intrathoracic pressure during inspiration -> decreased venous return to the heart -> decreased CO, BP, and tissue perfusion |
|
|
Term
| What are some ways to minimize inhalant concentration, and therefore minimize hypotension in acute abdomen surgical patients? |
|
Definition
| fentanyl, lidocain, or ketamine CRI |
|
|
Term
| What dosing considerations should be made in anesthetic patients with chronic GI diseases? |
|
Definition
| use lower doses because most anesthetic drugs are highly protein bound, and many patients with chronic GI disease are hypoproteinemic, resulting in more free drug within the circulation of these patients |
|
|
Term
| Which anesthetic drugs have minimal hepatic metabolism? |
|
Definition
|
|
Term
| what are common historical and PE findings associated with acute self limiting episodes of vomiting? |
|
Definition
| History of dietary indiscretion, drug exposure, concurrent diarrhea, normal or near-normal physical exam with infrequent bouts of vomiting |
|
|
Term
| What are some historical and PE findings suggestive of serious (potentially life threatening) vomiting? |
|
Definition
profuse or persistent vomiting; frequency may be increasing, hematemesis (+/- melena), incomplete vaccination status (young), depression, dehydration, apparent abdominal
pain, palpable abnormalities in abdomen, other concurrent signs systemic signs (fever, icterus, anemia) |
|
|
Term
| What is the minimum diagnostic testing necessary to work up a case of acute vomiting? |
|
Definition
PCV/TS (assess hydration)
+/- Abdominal radiographs
Fecal if concurrent diarrhea (obtain
by digital rectal) |
|
|
Term
| If you suspect a more serious cause for the vomiting (ie. frequent episodes, hematamesis/melena, PE abnormalities and systemic signs of illness) what should your minimum diagnostic database be? |
|
Definition
CBC
Serum chemistry profile (+/- lipase, cPL/fPL)
urinalysis
Survey abdominal radiographs
Ultrasound
+/- upper GI (barium) series
+/- Fecal flotation
**** primary or secondary GI? Do we need surgery? |
|
|
Term
| What two questions are we trying to answer with diagnostic tests in that case of suspected serious/life-threatening cases of acute vomiting? |
|
Definition
Is the vomiting due to primary or secondary GI disease? (CBC/CHEM/UA)
Does the case need surgery (imaging) |
|
|
Term
| What are the principles of symptomatic therapy for acute gastroenteritis? |
|
Definition
restore and maintain fluid and electrolyte balance
control clinical signs with antiemetics and antidiarrheal agents
introduction of small amounts of water followed by small frequent meals of highly digestible food as soon as vomiting is controlled (may need NPO for 6-24 hours if vomiting is profuse) <-- feeding has a gastroprotective effect b/c enterocytes get most of their nutrition from the gut lumen
gradual return to usual diet over 2-3 days |
|
|
Term
| What are the differences in content between "bland" (ie. highly digestible) diets for cats vs. those for dogs, in the treatment of acute gastroenteritis? |
|
Definition
Cats require high protein, moderate fat and low CHO
Dogs require adequate (not excessive) protein and minimal fat (fat slows gastric emptying and stimulates pancreatic and colonic secretion) |
|
|
Term
|
Definition
| non-digestible food components (ex. fructooligosaccharide) that stimulate the growth of beneficial enteric bacteria (ie. bifidobacterium and lactobacillus) |
|
|
Term
| What three viruses can cause enteritis and diarrhea in dogs? |
|
Definition
Parvovirus
also coronavirus and rotavirus (these are less prevalent and cause more mild clinical signs except in neonates) |
|
|
Term
| What is the only clinically important primary enteric virus in cats? |
|
Definition
|
|
Term
| What tissues are affected by canine parvovirus? |
|
Definition
| virus has an affinity for rapidly dividing cells ---> intestinal crypt necrosis, severe diarrhea, leukopenia and lymphoid depletion |
|
|
Term
| How is canine parvovirus transmitted? |
|
Definition
fecal-oral transmission
** massive amounts of virus are shed in the feces and can remain infectious in the environment for many months |
|
|
Term
| Although dogs of any age can be infected with canine parvovirus, which age groups are most susceptible to developing clinical disease? |
|
Definition
puppies between 6 weeks and 6 months of age
*** losing maternal protection and if unvaccinated no humoral immunity |
|
|
Term
| What laboratory and PE findings are consistent with canine parvovirus infection? |
|
Definition
| Profuse, bloody, fetid, fluid diarrhea accompanied by fever, depression, anemia, hypoproteinemia, and neutropenia |
|
|
Term
| T/F SNAP parvo test results are a reliable indication of active fecal excretion of virus and will also reliably detect feline panleukopenia virus |
|
Definition
|
|
Term
| T/F Modified Live Parvo vaccines may result in false positive results on SNAP tests |
|
Definition
FALSE
*** a positive SNAP confirms active viral shedding |
|
|
Term
| What are the three main therapies used to treat parvovirus infections in puppies? |
|
Definition
Fluid therapy
Parentral antibiotics (febrile and leukopenic animals are at high risk for bacterial gut translocation and sepsis)
NPO until vomiting is infrequent, trickle feeding with NE tube results in earlier clinical improvement and weight gain b/c enterocytes gain much of their nutrition from the gut lumen
+/- metaclopramide (persistant vomiting secondary to delayed gastric emptying) |
|
|
Term
| What is the prognosis for dogs infected with parvovirus? |
|
Definition
| most survive if treated appropriately for dehydration and sepsis. Once a dog survives the first 3-4 days of illness recovery is generally rapid |
|
|
Term
| How long should a puppy that has recovered from parvovirus infection be isolated from other dogs? |
|
Definition
1 week post recovery (may still be shedding virus at this point)
<-- clean environment with 1:32 bleach and water solution |
|
|
Term
| What vaccination protocols are recommended for prevention of parvovirus infection in puppies? |
|
Definition
inactivated vaccine in pregnant bitches
MLV vaccine in puppies starting at 6-8wks and repeating every 3-4 wks until preferably 18wks of age |
|
|
Term
| What are two potential complications that can occur in puppies following an episode of parvovirus infection? |
|
Definition
GI motility disruption (ex. intussusception)
Dietary hypersensitivity (anecdotal) |
|
|
Term
| What are four important elements that contribute to GI mucosal defense? |
|
Definition
cytoprotective secretions (mucus, HCO3)
mucosal prostaglandins (esp. class E)
high mucosal blood flow
high rate of epithelial cell turnover and restitution |
|
|
Term
| What cells are responsible for the secretion of gastric acid, and what substances are responsible for modulating acid secretion? |
|
Definition
parietal cells secrete gastric acid
hormones (gastrin), neurotransmitters (acetylcholine), and paracrine factors (histamine) modulate the production of gastric acid by the parietal cells |
|
|
Term
| What clinical picture is consistent with gastric ulceration? |
|
Definition
Vomiting +/-hematemesis
Melena
+/- Abdominal pain
Anemia:
Macrocytic early (ie. regenerative due to blood loss)
Microcytic, hypochromic later (chronic blood loss, iron deficiency) |
|
|
Term
| T/F hyperacidity is the most common pathogenesis of gastric ulcers in small animals |
|
Definition
FALSE
hyperacidity can cause ulcers when associated with gastrinoma, mastocytosis, and head trauma. A more common cause of ulcers in small animals is secondary to damaged mucosal defenses (many causes, NSAIDs are most common) |
|
|
Term
| What is the normal response of the stomach to damage of the mucus layer and erosion of the gastric epithelium? |
|
Definition
| production of prostaglandins -> increase mucosal blood flow and stimulate cell replication and restiution |
|
|
Term
| NSAID inhibition of which enzyme is associated with GI ulceration and nephrotoxicity? |
|
Definition
inhibition of COX-1 (constitutive)
**** this is why cox-2 (inducible, only present at sites of inflammation) specific NSAIDs are safer, but NO NSAID is free of ulcergenic capacity |
|
|
Term
| Which drug is particularly ulcergenic? |
|
Definition
| asprin <-- irreversibly inhibits cyclooxygenase and exerts local salicylate toxicity on gastric mucosal cells |
|
|
Term
| T/F corticosteroids are only associated with GI ulceration when used at high doses or in the presence of other ulcergenic factors (like NSAIDs) |
|
Definition
TRUE
*** secondary to inhibition of phospholipase, most commonly in the stomach and colon |
|
|
Term
| What is the pathogenesis of GI ulcers secondary to liver disease? |
|
Definition
Thromboplastin is released from the liver following an acute insult -> initiates the clotting cascade -> thrombosis and reduced gastric blood flow
reduced gastric blood flow is also the mechanism of ulcergenesis in the case of chronic liver disease; however, may be due to microvascular shunting and dysplasia of gastric vessels in addition to thrombosis |
|
|
Term
| What is the pathogenesis of GI ulcers secondary to chronic renal disease? |
|
Definition
most important is decreased mucosal blood flow secondary to diffuse vascular injury
also impaired mucus and bicarbonate secretion and acidosis (NOT gastric hypersecretion) |
|
|
Term
| what metabolic disorder can be associated with gastric ulcers? |
|
Definition
hypoadrenocorticism
*** pathogenesis is unknown, glucocorticoids may be necessary for gastric cytoprotection |
|
|
Term
| What is the major mechanism of ulcer formation secondary to stress? |
|
Definition
| increased sympathetic activity --> increased circulating catecholamines --> vasoconstriction and reduced gastric mucosal bloodflow |
|
|
Term
| T/F you can assess the normal stomach via abdominal palpation |
|
Definition
FALSE
*** may be palpable if distended |
|
|
Term
| What is the classic clinical presentation associated with chronic gastritis in dogs and cats? |
|
Definition
persistent, intermittent vomiting exacerbated by eating and drinking
*** PE,CBC,CHEM,UA,radiographs are typically unremarkable <-- need to do these diagnostics to r/o gastritis secondary to a non-GI disease process |
|
|
Term
| What are the two postulated etiologies of eosinophilic gastritis? |
|
Definition
hypersensitivity to dietary antigens
immune response to parasitic antigens |
|
|
Term
| How is presentation of eosiniphilic gastritis in cats different than that in dogs? |
|
Definition
| cats tend to have generalize hypereosinophilic syndrome (poor prognosis) while the disease is contained within the GI tract in dogs (prognosis is good with corticosteroid tx) |
|
|
Term
| What is the treatment of choice for eosinophilic gastritis? |
|
Definition
broad spectrum dewormer + corticosteroids
+/- hypoallergenic diet and surgical resection of esosinophilic granulomas |
|
|
Term
| What is the treatment for dogs with bilious vomiting syndrome? |
|
Definition
more frequent feeding (esp. a small meal late in the evening)
+/- H2 blocker and prokinetic agent administered before the longest interprandial interval (usually in the evening) |
|
|
Term
| What diagnostic test can be used to identify the presence of helicobacter-like organisms from a mucosal biopsy or brushing? |
|
Definition
| urea tubes ---> bright pink color change to the culture medium if the organisms produce urease (consistent with helicobacter-like organisms) |
|
|
Term
| What historical or PE findings warrant a more extensive work up for a patient with diarrhea? |
|
Definition
| chronic, moderate to severe, potentially zoonotic/infectious |
|
|
Term
| How many negative fecal floatations are necessary to rule out parasites? |
|
Definition
3 negative tests
*** fecal floats are not sensitive, therapeutic deworming is a viable option especially in young animals |
|
|
Term
| What clinical signs are associated with SI diarrhea? |
|
Definition
| weight loss, normal to increased frequency of defecation, increased volume of feces, melena |
|
|
Term
| What clinical signs are associated with LI diarreah? |
|
Definition
| increased frequency and urgency for defecation, decreased volume of stools, tenesmus, hematochezia, mucus |
|
|
Term
| What chronic enteropathies are associated with protein loosing enteropathy? |
|
Definition
lymphangiectasia
IBD
intestinal lymphoma
intestinal histoplasmosis |
|
|
Term
| Symptomatic management of diarrhea is appropriate in patients with what three characteristics? |
|
Definition
| normal attitude, no weight loss, no palpable abdominal abnormalities |
|
|
Term
| What blood test can be used to evaluate the absorptive capacity of the proximal small intestine? |
|
Definition
serum folate levels
*** decreased values with malabsorptive disease, elevated values with dysbiosis (bacterial overgrowth --> increased production of folate) |
|
|
Term
| What blood test can be used to assess absorptive capacity of the ileum? |
|
Definition
serum B12 (coalmin)
*** decreased values with bacterial overgrowth, malabsorption and EPI |
|
|
Term
| T/F the majority of animals infected with giardia are asymptomatic carriers |
|
Definition
TRUE
***clinical disease (acute small bowel diarrhea) tends to be most prevalent in young animals |
|
|
Term
| What is the gold standard for diagnosis of giardia? |
|
Definition
| zinc sulfate centrifugation and fecal IFA (both detect giardia cysts <-- generally more numerous in fecal samples than trophozoites) |
|
|
Term
| What drug is the treatment of choice for giardia? |
|
Definition
fenbendazole
*** metronidazole is LESS efficacious and associated with serious side effects at the high dose necessary to treat giardia (CNS effects) |
|
|
Term
| What would be two situations where asymptomatic cases of giardia should be treated? |
|
Definition
When young children, elderly individuals, or immunocompromised
individuals are in the household
If pet has extensive contact with other
pets and may serve as a reservoir |
|
|
Term
| What dietary management may be used to help prevent giardia infection? |
|
Definition
| High fiber diet provides a mechanical barrier to intestinal infection |
|
|
Term
| T/F a dog or cat with cryptosporidiosis poses a zoonotic threat and should be treated aggresively |
|
Definition
FALSE
the species that infects dogs and cats is not the same as the species that infects calves and humans. Clinical disease caused by cryptosporidium in dogs and cats is self limiting, minimal shedding, and does not require treatment. |
|
|
Term
| What clinical presentation is associated with tritrichomoniasis? |
|
Definition
large bowel diarrhea in young cats often characterized by hematochezia, fecal incontinence and marked inflammation of the anus
*** diarrhea resolves spontaneously, but may persist for as long as 2 years |
|
|
Term
| How can you differentiate giardia from tritrichomoniasis on fecal smear? |
|
Definition
| Giardia trophozoites tend to be fewer in number and have a more fluid motion, while trichomonas foetus protozoa move in a jerky forward motion |
|
|
Term
| Where do coccidial parasites reside and in what population of animals do they cause clinical disease? |
|
Definition
| reside in the posterior small intestine and tend to only cause clinical disease in young or immunocompromised individuals (large bowel diarrhea) |
|
|
Term
| What is the only drug that has been shown to help clear coccidiosis in puppies or immunocompromised adults? |
|
Definition
|
|
Term
| What nematode infects the stomach of cats and is not diagnosable on fecal floatation? |
|
Definition
ollalanus tricuspis
** females are viviparous, diagnosis is made via histologic examination of mucosal biopsy |
|
|
Term
| What three common types of GI parasites infect the SI in dogs and cats? |
|
Definition
| ascarids, hookworms, and tapeworms |
|
|
Term
| What GI parasite of dogs and cats infects the LI and cecum? |
|
Definition
|
|
Term
| Treatment of tapeworms in dogs and cats should always include what element? |
|
Definition
| flea control (D. caninum occurs secondary to flea ingestion) |
|
|
Term
| What clinical presentation is associated with ascarid infection in dogs and cats? |
|
Definition
| puppies and kittens, unthriftiness |
|
|
Term
| What clinical presentation is associated with hookworm infection? |
|
Definition
| puppies and dogs, blood loss anemia |
|
|
Term
| What clinical presentation is associated with whipworm infection? |
|
Definition
| puppies and dogs, rarely cats, watery diarrhea with frank blood at the end of defecation |
|
|
Term
| What clinical presentation is associated with tapeworm infection in dogs and cats? |
|
Definition
asymptomatic
may see segments (look like grains of rice) on stool or perineum |
|
|
Term
| how long are the intestine? |
|
Definition
|
|
Term
| What type of needle and suture material should be used for GI surgery? |
|
Definition
| always use a swaged on TAPERED needle with monofilament suture material |
|
|
Term
| What region of the small intestine is easiest to exteriorize from the abdomen? |
|
Definition
|
|
Term
| When doing an enterotomy where should you make you initial incision? |
|
Definition
always enter the bowel on the ANTI-MESENTERIC boarder
*** and if there's a FB incise distal to it in the healthy tissue |
|
|
Term
| When doing an intestinal resection and anastamosis why should you place the crushing clamps at an angle towards the normal bowel tissue? (ie. \ / )? |
|
Definition
| This ensures adequate blood supply to the antimesenteric boarder of the anastamosis |
|
|
Term
| Where should you place you first sutures when closing a bowel anastamosis? |
|
Definition
| place first sutures at mesenteric boarder to visualize the integrity and apposition from the lumenal side (otherwise mesenteric fat will obscure the enteric tissue) |
|
|
Term
| Up to what percentage of bowel can be resectioned with relatively few post op problems in adults? |
|
Definition
50%
*** up to 75-80% can be well tolerated in puppies |
|
|
Term
| What suplements should be provided to patients that have had their ileum and/or ileocolic junction resected (ex. tx for cats with megacolon)? |
|
Definition
give vitamin B12 injections as the ileum is the site of absorption for this vitamin
**** also site of absorption of bile salts |
|
|
Term
| T/F it is generally NOT reccomended to plicate the intestine to prevent recurrence of intussusception |
|
Definition
|
|
Term
| If you are resecting a portion of bowel due to neoplasia what tissues should you collect biopsies from before closing? |
|
Definition
liver and mesenteric lymph nodes
**** histopath for micrometastasis, also visually explore the entire abdomen for mets |
|
|
