Exam 2 Review Flashcards
What is the difference between vomiting and regurgitation?
**Vomiting is the forceful ejection of the contents (such as food, fluids, or debris) of the stomach and upper small intestine.
**Regurgitation is a passive motion that does not require effort or contraction of the abdominal muscles. Food and fluid tends to be undigested.
Vomiting of white fluid suggests a disorder of __ origin
Gastric or Esophageal
Vomiting of yellow fluid suggests gastric vomiting mixed with __
Bile from the duodenum
Vomiting of green fluid indicates the presence of bile that has come very recently from the duodenum.
Vomiting of both yellow and green fluid can be associated with pancreatitis.
Brown fluid suggests reflux of fecal-like material from further down the small intestine. It usually has a fecal-like odor as well.
Frank blood in the vomitus (hematemesis) typically indicates esophageal, gastric, or duodenal erosions or ulceration, although frank blood can be seen on occasion with jejunal disease.
Black flecks or “coffee grounds” indicate the blood has been present long enough in the stomach for the hydrochloric acid in the stomach to denature (digest) the hemoglobin.
Vomiting should be characterized as precisely as possible in all patients (Box 20.1). It is not uncommon for patients with complicated but also with uncomplicated GI problems to be undertreated because the vomiting has not been characterized adequately. This can lead to significant morbidity.
Metoclopramide acts by enhancing gastric emptying and increasing lower esophageal sphincter tone, and it acts centrally at the chemoreceptor trigger zone; clinically, metoclopramide appears to be most effective when given via CRI at 2mg/kg/day
Chlorpromazine (phenothiazine)
act at higher central nervous system centers and at the chemoreceptor trigger zone. They can cause significant hypotension, and BP should be monitored if any drugs in this class are being administered
Anticholinergics act by decreasing GI secretions and motility; however, these agents are almost never used because even a single dose can lead to prolonged ileus.
Serotonin antagonists such as ondansetron hydrochloride or dolasetron are very effective. Serotonin receptors are present in the chemoreceptor trigger zone, peripherally on vagal nerves, and in the GI tract; however, how the drug controls vomiting is unknown
Maropitant (Cerenia, Zoetis Inc., Florham Park, NJ) appears to be the most clinically effective antiemetic currently available. It is a neurokinin-1 (NK1) receptor antagonist. It inhibits binding of substance P (which helps initiate vomiting) in the chemoreceptor trigger zone and the vomiting center.
Butorphanol is a mild antiemetic that counteracts the nausea caused by certain medications (especially chemotherapeutic agents) and may help decrease vomiting caused by pain.
Parenteral antiemetics should be used in most vomiting patients, because oral medications can cause vomiting and GI absorption is unreliable. Whenever possible, the drugs should be given IV to ensure good blood levels.
Nonsteroidal antiinflammatory drugs should be avoided because of their negative effects on splanchnic organs (and, in some cases, coagulation)
esophageal foreign body. The animal may show signs of salivation, excessive swallowing motions, dysphagia, and apparent vomiting that on closer questioning will be determined to be regurgitation.
respiratory distress, because the foreign material may be compressing the trachea.
Early signs of a GI foreign body include nausea, vomiting, and inappetence. Vomiting usually persists until the material has been vomited, has passed, or has been removed
Abdominal pain may or may not be present
Surgery is indicated in the vast majority of these patients. If only mild clinical signs are present, then a watch-and-wait attitude may be adopted.
gastric dilation and volvulus (GDV) is not yet clearly understood. GDV has been associated with many clinical diseases and typically is seen in large, deep-chested dogs; however, it can occur in any size of dog, at any age.
Twisting causes a one-way valve effect at the gastroesophageal junction, allowing swallowed air to enter the stomach but not leave. Carbon dioxide may also accumulate secondary to bacterial fermentation, diffusion from trapped blood, and metabolism of gastric acid and bicarbonate from the pancreas and saliva.
a history of attempting to vomit or having nonproductive retching, although occasionally all the owner reports is the dog is more quiet than normal. Abdominal distention may or may not be noted by the owner.
On presentation, dogs usually show some degree of circulatory shock. Ventilatory compromise may be evident because of pressure on the diaphragm from the distended stomach.
A right lateral abdominal radiograph will typically reveal a characteristic shelf sign with compartmentalization, supporting a diagnosis of a gastric volvulus
It is, however, very common to have extremely high lactate concentrations of 10mmol/L or higher, often as high as 20mmol/L with GDV.
Immediate treatment should consist of O2 administration if the dog is showing any signs of shock, as well as volume replacement with crystalloids with or without synthetic colloids.
A lead II ECG should be monitored, because these dogs are prone to ventricular arrhythmias
hemorrhagic gastroenteritis (HGE) usually is unmistakable because of the presence of blood (frank or digested) in the vomitus or diarrhea
foul odor to the stool is also usually present
Acute hemorrhagic diarrhea syndrome (AHDS) is characterized by a very high PCV (usually >60%) and relatively low TSs
Synthetic colloids the intravascular volume more rapidly than crystalloids IV broad-spectrum antibiotics are usually indicated.
Pancreatitis ultimately is a result of activation of the pancreatic enzymes (proteases) within the pancreas, leading to autodigestion, as well as digestion of the peripancreatic tissues, and subsequent activation of the inflammatory process through neutrophil activation and production of cytokines and free radicals.
Multiple causes of pancreatitis have been identified; however, most cases are ultimately diagnosed as idiopathic. Dietary indiscretion appears to be a common predisposing factor in dogs, and cholangiohepatitis and inflammatory bowel disease appear to be involved in many cats.
Anorexia and intermittent vomiting may be the only signs in cats. Dogs often have a history of dietary indiscretion followed by nausea, vomiting, and anorexia. Diarrhea may be present. Abdominal pain is usually present; in mild cases, pain can be localized to the upper-right quadrant of the abdomen in dogs, and in more severe cases it may be diffuse
Assays of pancreatic enzymes (amylase, lipase) do not provide any useful information in dogs and cats. Species-specific pancreatic lipase immunoreactivity (fPLI and cPLI) tests are used to help diagnose pancreatitis in both species
Bleeding in smaller vessels may be controlled by a simple response involving the vasculature and platelets, known as primary hemostasis. With larger-vessel injury, plasma coagulation factors are needed to form a stable clot, a process known as secondary hemostasis. Dysfunctions of the hemostatic system lead to life-threatening conditions through a variety of mechanisms.
The first response to blood vessel injury is vasoconstriction, temporarily diverting blood flow around the injured area.
Plasma coagulation factors (denoted by Roman numerals) are produced in the liver, many with the help of vitamin K (II, VII, IX, and X), and are enzymes or cofactors to enzymatic processes
Patients with a low platelet count, known as thrombocytopenia, experience bleeding when inadequate numbers of platelets are available to form a platelet plug (spontaneous bleeding typically does not occur unless platelet concentration is <20,000 to 30,000/μL).
Primary Hemo
Massive transfusion may cause thrombocytopenia from a combination of the rapid consumption of platelets and the dilution of platelet concentration by fluid solutions and blood components. Thrombocytopenia can also result from an increased consumption of platelets attributable to DIC, infection, neoplasia, inflammation, immune-mediated disorders, and drug interactions.
__ is a common cause of increased platelet sequestration and destruction with subsequent thrombocytopenia. __ occurs when immunoglobulin G (IgG) against platelet membrane elements are produced and bound, resulting in premature removal by the reticuloendothelial system.
Immune-mediated thrombocytopenia (IMT)
IMT can be classified into two types. These are __
Primary: Antiplatelet antibodies are truly autoimmune and have no apparent cause.
OR
Secondary: Disorder is warranted if antibodies are produced in response to antigenic stimuli (e.g., drugs, vaccines, infections, and neoplasia).
__ formation is a cause of hemolytic anemia. It is the result of oxidative damage to erythrocyte hemoglobin.
Heinz Body
IMHA may be a primary disease, also known as idiopathic or autoimmune hemolytic anemia, in which autoantibodies are produced against the unaltered RBC membrane.
