SPECIAL CONSIDERATIONS FOR EMERGENCY SURGERY PROTOCOL
(For standard recommendations, see General Anesthesia Considerations for All Procotols, page 83.)
Preoperative assessment
■ Stabilize prior to anesthesia:
● Manage shock.
● Initiate shock treatment with the appropriate crystalloid fluid. Dogs: 20 mL/kg bolus (up to 80 mL/kg). Cats: 5 mL/kg bolus (up to 40 mL/kg). Hetastarch may also be administered if needed at the following doses: Dogs: 5 mL/kg bolus (up to 20 mL/ kg/day). Cats: 2.5 mL/kg bolus (up to 10 mL/kg/day).
● Manage arrhythmias.
● If ventricular tachycardia (V tach) or > 30% ventricular premature contractions (VPC) AND systolic blood pressure (sBP) < 90, mean arterial pressure (MAP) < 60, or Sp02 < 95 (on oxygen) administer lidocaine 2 to 4 mg/kg (dogs) or 0.25 to 0.5 mg/kg (cats) IV, then place a second IV catheter and begin a lidocaine CRI.
● Begin to correct dehydration and electrolyte abnormalities.
● Begin transfusions on significantly anemic patients or those where significant acute hemorrhage has occurred.
● Provide oxygen if indicated.
● Provide pain management (butorphanol 0.2 to 0.4 mg/kg SC, IM q one to four hours as needed).
● Avoid the use of NSAIDs, or use with extreme caution, in patients with dehydration, shock, renal impairment or underlying gastrointestinal disease. For this reason, the use of NSAIDs in critical patients is limited until they are stabilized. The most recent research indicates that COX-2 is an important component in gastrointestinal healing and that COX-2 NSAIDs such as carprofen or meloxicam should be avoided in cases where gastrointestinal injury may be present, either as a result of vomiting, primary gastrointestinal disease or gastrointestinal surgery. In these cases, the use of opioids is more appropriate postoperatively.
● True emergencies requiring immediate anesthesia are rare. A true emergency requiring immediate surgery would include an airway obstruction or acute life-threatening hemorrhage. Most pets will have a better outcome if stabilized before anesthesia or surgery. For example, the survival rate for patients with traumatic diaphragmatic hernias greatly increases if the pet is stabilized at least 24 hours prior to surgery. Gastric dilatationvolvulus (GDV) cases require stabilization and decompression before general anesthesia for the best patient outcome. These examples don’t meet the definition of “emergency” as used in this protocol. Emergencies are surgical cases that require anesthesia within 15 minutes to save the patient’s life.
● Perform as complete a physical examination as possible. If the urgency of the situation precludes preanesthetic blood work, run it as the patient is being examined and anesthetized.
● Assess cardiovascular parameters before induction. An electrocardiogram (ECG) may be beneficial during cardiac assessment.
Premedications
■ Do not use acepromazine.
■ The IV route is preferred for premedication in true emergency cases to allow for rapid induction and intubation and the establishment of a patent airway (See Special Considerations for Emergency Surgery Protocol, page 106).
■ With true emergency anesthesia, premeds, including butorphanol, may not have had time to take complete effect prior to induction.
Induction
■ Use the minimum amount of drugs for induction and the lowest sevoflurane percentage possible for the situation. The average dose of propofol is often less than is required by healthy pets. Err on the side of caution. Propofol should be administered slowly to effect, to minimize adverse cardiovascular effects. Bradycardia and apnea may develop after rapid administration.
Maintenance and monitoring
■ Overpressure may not be necessary in severely compromised patients.
■ Monitor closely to see if patient is getting deeper because of premeds, and decrease sevoflurane, if appropriate.
■ Repeat lab work as needed, especially in surgeries lasting more than one hour, consider rechecking packed cell volume, total protein (PCV/TP), blood glucose (BG) and/or electrolytes.
■ Critically ill patients may be slow to recover from anesthesia. Monitor and document temperature, pulse and respiration (TPR) and other vitals frequently and provide supportive care, supplemental heat and pain management as necessary.
■ Provide appropriate pain medications postoperatively (See Anesthesia Task Pain Chart, pages 18-19; see notes at top of page 106 regarding NSAIDs).
Postoperative pain management and to go home
■ Critical patients should be transferred to an overnight emergency clinic or 24-hour referral hospital for continued care postoperatively.
■ Postoperative pain management is imperative to the successful surgical and medical management of the emergency or critical patient. Pain management must be tailored to the individual patient. Refer to the General Anesthesia Considerations for All Protocols on page 83 for treatment options. Utilize the Colorado State University acute pain scale guidelines on pages 16-17, to closely and frequently monitor the patient and provide adequate pain control.