Page 89 - Cote clinical veterinary advisor dogs and cats 4th

22 Acute Abdomen

ulcer); strangulation (e.g., through a • Referred or apparent abdominal pain due (1.4× peripheral in dogs, 1.9× peripheral
hernia); mesenteric volvulus; colonic to spinal pain (e.g., intervertebral disc disease ○ Intra-abdominal source of sepsis is likely
in cats) is consistent with uroabdomen.
VetBooks.ir ○ Medical: gastroenteritis/dietary indiscre- Initial Database if the peripheral glucose concentration is
[IVDD], discospondylitis, trauma)
torsion
tion; hemorrhage/ulceration; infectious
20 mg/dL (1.1 mmol/L) ≥ the abdominal
(parvovirus, parasites)
lactate concentration is ≤ 2 mmol/L above
• Liver • Packed cell volume (PCV)/total plasma glucose concentration and if the blood
protein (TPP) or total solids (TS): may
○ Surgical: neoplasia; abscess; bile peritonitis identify anemia or hemoconcentration the abdominal fluid lactate concentration.
○ Medical: acute hepatic injury (leptospi- ○ Low TPP/TS in face of a normal or • Point-of-care canine-specific pancreatic lipases
rosis, ascending portal infection, severe elevated PCV is concerning for acute tests have a high false-positive rate for dogs
intoxication), certain forms of neoplasia blood loss but may also reflect hypopro- with signs of acute abdomen. A negative test
• Pancreas teinemia from vasculitis, hepatic disease, result likely rules out the presence of pan-
○ Surgical: neoplasia, abscess or other cause. creatitis, but a positive test result requires
○ Medical: pancreatitis (surgery seldom • Lactate: elevated blood lactate concentration further diagnostics to confirm or refute its
recommended for pancreatitis) usually reflects hypoperfusion due to volume presence (e.g., imaging). Feline-specific
• Spleen depletion or distributive shock. pancreatic lipase testing is also available.
○ Surgical: neoplasia, torsion, trauma, • CBC and blood smear evaluation: leukocy-
abscess tosis or leukopenia, thrombocytopenia, Advanced or Confirmatory Testing
• Urogenital anemia, erythrocytosis possible • Fine-needle aspirates or biopsies of lesions
○ Surgical: pyometra, urolithiasis, trauma, ○ Thrombocytosis may be identified in cases (pp. 1064 and 1112)
ureteral obstruction, prostatic infection, of chronic GI hemorrhage. • Platelet count, hemostatic tests (p. 1325)
neoplasia, uterine torsion, testicular torsion ○ The presence of band neutrophils (left (prothrombin time, activated partial throm-
○ Medical: pyelonephritis, urethral obstruc- shift) is compatible with severe inflam- boplastin time, activated clotting time),
tion, urolithiasis, neoplasia mation or infection. buccal mucosal bleeding time (p. 1076), and
• Adrenal • Serum biochemistry analysis: hypoprotein- thromboelastography are indicated to better
○ Surgical: carcinoma, pheochromocytoma emia, azotemia, electrolyte derangements, characterize hemorrhagic conditions if a
• Generalized peritoneal disease liver enzyme elevations, hyperbilirubinemia, focal source for hemoperitoneum is not
○ Surgical: septic peritonitis (e.g., ruptured glucose abnormalities possible identified.
viscus, bite wounds), chemical peritonitis • Urinalysis: pyuria, bacteruria, crystalluria
(e.g., uroabdomen) possible. Avoid cystocentesis if pyometra TREATMENT
○ Medical: neoplasia (e.g., carcinomatosis) suspected or if coagulopathy likely.
• Systemic disorders • Abdominal radiographs: evaluate for radi- Treatment Overview
○ Medical: hemorrhage, thromboembolism, opaque foreign bodies, obstructive intestinal • Rapidly assess if patient has surgical or
congestive heart failure, hypoalbuminemia, gas patterns, organ enlargement, or displace- nonsurgical disease.
vasculitis ments (double bubble sign with GDV, large • Definitive treatment is based on underlying
Pathophysiology: fluid-filled uterus) and loss of detail seen cause (e.g., ovariohysterectomy for pyometra,
• Abdominal pain is due to stimulation of with abdominal effusion. Free peritoneal gas splenectomy for bleeding splenic mass).
nociceptors in the abdominal organs and in the absence of recent abdominal surgery • The main goals of emergent care are to
peritoneum. can be seen in cases of a ruptured viscus, optimize tissue perfusion by restoring and
• Hemodynamic instability is a common anaerobic infection, or after penetrating maintaining blood volume by means of resus-
sequela to acute abdomen (e.g., hemoabdo- trauma. citation with fluids and/or blood products
men, septic peritonitis) due to fluid loss. ○ Right lateral and ventrodorsal projections with or without the use of vasopressors and
Vasodilation associated with systemic inflam- preferred; horizontal beam radiography positive inotropes.
matory response syndrome may also be may be helpful to confirm pneumoperi-
present. Prompt resuscitation with intrave- toneum; pneumocolon may be helpful to Acute General Treatment
nous fluids with or without vasopressors is distinguish different bowel segments • Cardiovascular support: intravenous fluid
a priority even before definitive diagnosis or • Abdominal ultrasound: evaluate for abdomi- therapy is the mainstay of therapy in
therapy is recommended. nal effusion, GI obstruction, or the presence hypotensive and hypovolemic patients or
of foreign material, intra-abdominal masses, those with extensive third-space losses.
DIAGNOSIS abscesses; evaluation of the biliary tract, ○ Isotonic crystalloids are typically used,
pancreas, and urogenital system (operator but hypertonic saline, synthetic colloids,
Diagnostic Overview dependent) albumin and blood products may also be
• The key decision regarding patients with an ○ Ultrasound can aid with abdominocentesis considered, depending on the underlying
acute abdomen is whether emergent surgical or fine-needle aspiration of masses or disease and based on assessment (and
intervention is required. organ parenchyma. reassessment) of perfusion parameters,
• History, physical examination, baseline • Computed tomography: may be a more lactate concentration, urine output, and
laboratory data (including cytologic and sensitive abdominal imaging modality, blood pressure.
laboratory analysis of peritoneal fluids), and especially in large-breed or deep-chested dogs ○ Patients with persistent hypoperfusion or
diagnostic imaging findings all aid in reach- • Abdominocentesis (pp. 1056 and 1343): hypotension refractory to adequate fluid
ing this important decision. analysis of effusion may aid rapid identifica- resuscitation may require treatment with
• A diagnostic approach to peritonitis is tion of underlying problem by assessing fluid a vasopressor and/or positive inotropic
outlined on p. 1439. characteristics (e.g., PCV/TP, concentrations support (p. 907).
of glucose, lactate, potassium, creatinine, and • Pain management: opioids usually are first-
Differential Diagnosis total bilirubin) and cytology (e.g., intracel- line therapy; adjunctive analgesia may be
• Chronic abdominal disorder with acute lular bacteria in neutrophils consistent with provided with ketamine, lidocaine, and
exacerbation septic effusion) dexmedetomidine (if the patient is cardio-
• Tension/abdominal guarding on exam in ○ High effusion creatinine (at least 2× vascularly stable) by constant-rate infusion
anxious patient peripheral) and/or potassium concentrations and local/regional analgesia. Constant-rate

www.ExpertConsult.com