Page 978 - Problem-Based Feline Medicine

970 PART 11 CAT WITH AN ABNORMAL GAIT

Diagnosis fresh whole blood if anemic, plasma if hypoalbumine-
mic, and give clotting factors via fresh whole blood or
Diagnosis is based primarily on clinical signs and
fresh frozen plasma if coagulopathic. Do not use a glu-
history, especially if a site of infection is found.
cose solution unless hypoglycemic.
Finding of the “shock triad” of hypotension, brady-
Cardiac pumping support via use of positive
cardia, and hypothermia is highly suspicious.
inotropes (dopamine, dobutamine, epinephrine) is
White cell count alterations are common. Neutro- essential.
philic leukocytosis with left shift may be evident, but
Resuscitation goals are to restore oxygen delivery
with overwhelming sepsis, leucopenia with neutrope-
through correction and maintenance of arterial pres-
nia or a degenerative left shift occur. Monocytosis
sure, and adequate arterial oxygen content. The aims
occurs with long-standing or deep-seated infection.
are to correct hypothermia, hypovolemia, bradycardia
Thrombocytopenia can be seen from day 1. and anemia. If perfusion is still inadequate, address
hypotension with inotropic and vasopressor support.
Red cell count changes include anemia from hemoly-
sis, or a falling PCV and schistocytes associated with Rewarm with warm intravenous fluids, warm humidi-
DIC. fied oxygen, forced air heating, incubators and circulat-
ing water blankets. Care is necessary as active external
Coagulation testing (PT, APTT, ACT, FDPs) may indi-
rewarming can cause a paradoxical decrease in core
cate DIC.
temperature, acidosis and shock, because of the return
Hypoalbuminemia is common. of cold blood with lactic acid from the periphery.
Icterus is common, and usually results from hemolysis Bradycardia is treated with adequate warming, fluid
rather than cholestasis. bolus, atropine (0.04 mg/kg IV), and a positive
inotrope/chronotrope.
Hypovolemia is treated with crystalloids (55–60 ml/kg
Differential diagnosis
bolus rate IV) and colloids (5 ml/kg bolus rate IV). Adjust
Rule out other causes of acute muscle weakness such as fluid rate to maintain envolemic status. Monitor respira-
metabolic, inflammatory or toxic causes. tory rate and depth, and lung sounds carefully because
pulmonary edema and pleural effusion are common.
Identification of a focus of infection such as peritonitis,
pyothorax, pyometritis, pyelitis or subcutaneous Hypotension refractory to fluid therapy is treated with
abscess helps to differentiate sepsis from other causes exogenous catecholamines, but many patients become
of weakness. refractory after 72–96 hours.
● Dopamine (5–20 μg/kg/min CRI) has positive
Weakness with hypothermia, hypotension and
inotropic, chronotropic and some vasoconstrictor
bradycardia are pathognomonic.
effects, and has few adverse side effects.
● Dobutamine (5–20 μg/kg/min CRI) increases car-
diac output and oxygen delivery. Seizures occur
Treatment
with continued (> 24 hours) use.
The basis of therapy is ventilation, infusion, and ● Epinephrine (0.05–0.1 μg/kg/min CRI).
pumping (VIP), together with early antimicrobial ● Vasopressin.
treatment.
Anemia requires red cell transfusion if the PCV is less
Ventilation reduces the work of breathing, and than 20%.
includes oxygen, PEEP, intubation and/or mechani-
Pain control helps maintain mental well-being, and is
cal ventilation as necessary.
titrated to effect as responses are variable and affected
Infusion of fluids is essential. Colloids rapidly by underlying hepatic and renal dysfunction:
increase intravascular volume, and can be combined ● For mild to moderate pain use butorphanol
with crystalloids to support interstitial volume. Use (0.2–0.8 mg/kg IV q 2–6 h).