Small Animal Surgical Emergencies. Группа авторов

(Schering‐Plough) Sedation: 2–10 mg/kg IV, IM Loading dose: 0.5–1 mg/kg IV CRI: 0.1–0.6 mg/kg/hour Caution with hypertension, heart disease Controversial in head trauma, increased ICP/IOP, renal disease (cats) Alpha‐2 Adrenergics Dexmedetomidine HCl Dexdomitor^® (Pfizer) Sedation: 1–10 μg/kg IV, IM Loading dose: 0.5–1 μg/kg IV CRI: 0.25–3 μg/kg/hour Caution with cardiovascular disease or instability Atipamezole Antisedan^® (Pfizer) Alpha‐2 Adrenergic reversal: 0.05–0.2 mg/kg IV, IM Same volume as dexmedetomidine given IM Benzodiazepines: Midazolam 0.1–0.5 mg/kg IM, IV CRI: 0.1–0.5 mg/kg/hour Diazepam 0.1–0.5 mg/kg IV CRI: 0.1–0.5 mg/kg/hour Propylene glycol vehicle; avoid prolonged IV use or IM injection Flumazenil Benzodiazepine reversal: 0.01–0.02 mg/kg IV May need to be repeated after 20–30 minutes as required Phenothiazines: Acepromazine Aceproject^® (Fort Dodge Animal Health) 0.005–0.01 mg/kg IV every 4–6 hours 0.01–0.05 mg/kg IM, SQ every 4–6 hours Caution in hypovolemia Do not exceed 2 mg/kg in large dogs Non‐steroidal anti‐inflammatory drugs: Carprofen Rimadyl^® (Pfizer) Dogs: 2–4 mg/kg IV, SQ (single dose) Dogs: 2 mg/kg PO 12 or 4 mg/kg PO once daily24 hours IV or SQ should only be given when normothermic/normotensive Deracoxib Deramaxx^® (Novartis) Dogs: 1–2 mg/kg/day Meloxicam Metacam^® (Boerhringer Ingelheim) OroCAM^® (Abbott Laboratories) Dogs: 0.1–0.2 mg/kg IV, SQ (single dose) Dogs: 0.1 mg/kg PO or transmucosal once daily Black box warning for cats Transmucosal oral spray for dogs > 2.5 kg Piroxicam Feldene^® (Pfizer) Dogs: 0.3 mg/kg PO once daily Robenacoxib Onsior^® (Novartis) Dogs: 2 mg/kg SQ 30 minutes before start of surgery then every q 24 hours for a maximum of 3 days Dogs: 1–2 mg/kg PO once daily Cats: 2 mg/kg SQ 30 minutes before start of surgery then every q 24 hours for a maximum of 3 days Cats: 1 mg/kg PO once daily for a maximum of 3 days Do not divide/break/crush feline tablets, therefore, dose range in cats of 1–2.4 mg/kg Do not use in dogs or cats less 4 months of age Do not use tablets in cats < 2.5 kg

      CRI, constant rate infusion; ICP, intracranial pressure; IM, intramuscularly; IOP, intraocular pressure; IV, intravenously; NMDA, N‐methyl‐d‐aspartate; PO, per os (orally); SIADH, syndrome of inappropriate anti‐diuretic hormone.

      Fluid therapy in the burned veterinary patient requires special consideration, especially with respect to percentage of total body surface area affected. For information on fluid therapy for the burned patient, see Chapter 53.

      Regardless of fluid type and rate used to treat shock and or dehydration, frequent patient reassessment is critical. General recommendations for patient re‐evaluation are listed in Table 1.2.

Neurologic Assessment

      Initial neurologic assessment often occurs concurrently with respiratory and cardiovascular triage. Patients with normal consciousness are alert and aware of their environment. Obtunded patients have decreased responsiveness that can vary in severity. Stuporous patients are only responsive to noxious or excessive stimuli, whereas comatose patients do not respond to any stimuli. Decreased cerebral perfusion and oxygenation from hypovolemic, hypoxemic, distributive, and cardiogenic shock can have profound effects on mentation, so the patient's initial neurologic assessment must be made with patient's global perfusion status in mind. In both veterinary and human patients with traumatic brain injury, most have also sustained concurrent injuries to other major body systems that can have secondary neurologic consequences [76, 77]. Hypoglycemia (metabolic shock) can also lead to decreased mentation and must be treated before an accurate neurologic examination can be performed. As with other body systems, frequent neurologic reassessment is imperative.

      While performing the neurologic evaluation, until adequate oxygenation is confirmed, supplemental oxygen should be provided by mask, flow by, or placement of the patient in an oxygen cage. In patients with head trauma, nasal prongs or nasal oxygen catheter are avoided to decrease the risk of sneezing, which can increase their intracranial pressure (ICP). Heart rate and blood pressure values can also provide important insight about the presence of increased ICP. The Cushing's reflex, which is hypertension and reflex bradycardia, is commonly seen in patients with cerebral edema, hemorrhage, skull fractures, and intracranial masses. To maintain cerebral perfusion pressure (CPP) in the face of intracranial hypertension, arterial blood pressure (MAP) is increased, since CPP equals MAP minus ICP. Pressure receptors in the aortic arch and carotid bodies trigger a decreased heart rate in response to the increase systemic blood pressure. Treatment of intracranial hypertension is imperative and is accomplished with a combination of patient positioning and pharmacologic intervention with mannitol or hypertonic saline. If there is any evidence of or concern for head trauma or ICP, the patient's head should be elevated 15–30 degrees using a flat board or other rigid surface. Pillows should not be used to elevate the patient's head, as this can cause compression of the jugular vein(s), which impairs cerebral venous outflow. Jugular venipuncture should also be avoided. Mannitol (0.25–1 g/kg IV over 15–20 minutes) is an effective osmotic diuretic to decrease intravascular volume and facilitate fluid movement from the central nervous tissue, as with cerebral edema. The resultant diuresis will lead to dehydration if mannitol administration is not followed by intravenous fluid therapy in patients that cannot or will not drink. Hypertonic saline (7.5%, 3–5 ml/kg IV over 15–20 minutes in dogs, 2–3 ml/kg IV over 15–20 minutes in cats) is also effective for treating intracranial hypertension secondary to cerebral edema and works via free water osmotic shifting out of the tissue and into the hypertonic intravascular space created by the increased sodium load [78]. Concentrated (21%) sodium chloride can be combined with 0.9% saline to create a 7.5% solution by mixing 17 ml of 21% saline with 43 ml of crystalloid. The use of corticosteroids is contraindicated in patients with head trauma, as they can contribute to gastrointestinal ulceration, especially after an episode of hypoperfusion, and precipitate hyperglycemia, which has been associated with a worsened neurologic injury in veterinary patients [79].

Veterinary patients with any history of or