Anesthesia of the High Risk Patient Flashcards
What are the general principles of anesthetizing a high-risk patient?
Same as any patient:
- Identify any pre-existing problems pre-op: History, clinical examination + screening or diagnostic tests
- Minimize their effects: by stabilizing the patient through IV fluid therapy and start treatments for the respective disease present
- Anticipate any problems and emergencies: be ready for the worst
- Use “best practice”: secure venous access + intubate trachea + use drugs that can be given to effect
- Use ‘balanced’ anesthesia: achieving analgesia, hypnosis, and muscle relaxation
- Monitor patient aggressively
- Provide appropriate post-op care: analgesia, oxygen, and fluids
A patient presents with pyometra, and surgical treatment is necessary, what are the important pre-operative disorders and considerations before going into surgery?
- Dehydration + hypovolemia
- Azotemia
- Acidosis
- Toxemia
- Pyrexia
- Anemia
A patient presents with pyometra, and surgical treatment is necessary, what actions can be done to minimize the pre-operative disorders that are present?
- IV cannula + Fluids (LRS) for several hours
- Antibiotics (IV)
+/- supplemental oxygen
+/- blood transfusion if highly anemic
+/- bicarbonate to correct a severe acidosis (rarely needed though as the acidemia should correct itself once fluids are given)
A patient presents with pyometra, and surgical treatment is necessary, what major complications may occur during anesthesia/ surgery and how can these be treated?
Hypotension:
- Vasodilation –> fluid therapy
- Myocardial depression –> dobutamine (positive inotrope)
Arrhythmias:
- VPC’s –> Lidocaine if Cardiac Output is affected
Hypercarbia:
- IPPV
Hemorrhage:
- Fluid boluses or blood transfusion
A patient presents with pyometra, and surgical treatment is necessary, what anesthetic protocol is most appropriate for this patient (pre-med, induction, maintenance, and analgesia)
Pre-med: mu-agonist opioid + sedative (type of sedative depends on state of animal)
- Septic, hypovolemic, lethargic: use midazolam + opioid
- Lively, and fluids have been corrected: use low dose Acepromazine + opioid
Induction: Propofol, alfaxalone or Ket/Val
Maintenance: Isoflurane or Sevoflurane +/- CRI (opioid, ketamine or lidocaine, to reduce the amount of inhalant needed)
Analgesia: Opioids
- Not NSAIDs until renal function is known and dehydration is corrected
A patient presents with pyometra, and surgical treatment is necessary, what post-operative management is needed for this patient?
- IV fluids for the following 24-48 hours
- Measure PCV and urine output
- Measure urea + creatinine to get a status on kidney function
- Provide analgesia for 48-72 hours with an opioid +/- local techniques. Avoid NSAIDs if kidney function is compromised
A 6-year-old cat is involved in an RTA 3 days ago, a ruptured bladder is suspected, what are the important pre-operative disorders and considerations before going into surgery?
- Hyperkalemia +/- cardiac arrhythmias
- Hyponatremia
- Uremia
- Azotemia
- Metabolic acidosis
- Dehydrated
A 6-year-old cat is involved in an RTA 3 days ago, a ruptured bladder is suspected, what actions can be done to minimize the pre-operative disorders that are present?
- IV catheter + fluid therapy (LRS or dextrose saline +/- bicarbonate
- Urinary catheter placed
- Drain abdomen of urine and replace with warm saline or D5W and drain
- Treat hyperkalemia: with dextrose + insulin
- Myocardium stabilization: with Calcium gluconate
A 6-year-old cat is involved in an RTA 3 days ago, a ruptured bladder is suspected, what major complications may occur during anesthesia/ surgery and how can these be treated?
There should be minimal complications if the patient has been appropriately stabilized
A 6-year-old cat is involved in an RTA 3 days ago, a ruptured bladder is suspected, what anesthetic protocol is most appropriate for this patient (pre-med, induction, maintenance, and analgesia)
Any sensible technique if the patient has been well stabilized
A 6-year-old cat is involved in an RTA 3 days ago, a ruptured bladder is suspected, what post-operative management is needed for this patient?
- IV fluids for 24-48 hours after
- Monitor urine output and K+ levels
Caution: AVOID NSAIDs until renal function is normal
A 4-year-old Springer Spaniel is admitted for a C-section after straining for 2 hours, what are the important pre-operative disorders and considerations before going into surgery?
- Dehydration
- Fatigue!
A 4-year-old Springer Spaniel is admitted for a C-section after straining for 2 hours, what actions can be done to minimize the pre-operative disorders that are present?
- IV fluid therapy +/- Dextrose supplementation
- Gastric protectants: Omeprazole + Cerenia
- Pre-oxygenation
- Intubate rapidly to prevent aspiration
- Provide IPPV if not breathing well
- Monitor patient depth carefully
A 4-year-old Springer Spaniel is admitted for a C-section after straining for 2 hours, what major complications may occur during anesthesia/ surgery and how can these be treated?
- Regurgitation at induction
- Respiratory depression + hypercarbia
- Hypovolemia + Hypotension
- Hypoxemia
- Hemorrhage
- Toxemia if the pups are dead
- Hypoglycemia
- Resuscitation of puppies
A 4-year-old Springer Spaniel is admitted for a C-section after straining for 2 hours, what anesthetic protocol is most appropriate for this patient (pre-med, induction, maintenance, and analgesia)
Pre-med: NONE or low dose ACP or BZD
NO alpha2-agonist due to vasoconstriction and decreased CO
Induction: Propofol or alfaxalone
Maintenance: Minimum requirement of isoflurane or sevoflurane
Analgesia: Epidural + line block
A 4-year-old Springer Spaniel is admitted for a C-section after straining for 2 hours, what post-operative management is needed for this patient?
- Analgesia with minimal sedation so that the dam can feed her pups: Local, NSAIDs for 3 days, or Buprenorphine
- Keep warm
- Encourage puppies to feed
A 6-year-old red setter presents with retching and a distended abdomen, x-rays confirm a gastric-dilation-volvulus, what are the important pre-operative disorders and considerations before going into surgery?
- Hypovolemia + decreased venous return + low cardiac output
- Low tissue perfusion
- Decreased tidal volume
- Shock
- Arrhythmias
- Acid/base imbalances
- Toxemia +/- septicemia
A 6-year-old red setter presents with retching and a distended abdomen, x-rays confirm a gastric-dilation-volvulus, what actions can be done to minimize the pre-operative disorders that are present?
- 2 large bore IV cannulae + rapid IV fluids
- Decompress stomach prior to surgery: stomach tube or trochar
- Diagnose arrhythmias + treat
- Diagnose acid-base status
A 6-year-old red setter presents with retching and a distended abdomen, x-rays confirm a gastric-dilation-volvulus, what major complications may occur during anesthesia/ surgery and how can these be treated?
- Regurgitation at Induction: Intubate trachea rapidly and cuff
- Shock, Hypotension, Vasodilation: IV boluses
- Malignant arrhythmias
- Hemorrhage
- Inadequate respiration: give IPPV
A 6-year-old red setter presents with retching and a distended abdomen, x-rays confirm a gastric-dilation-volvulus, what anesthetic protocol is most appropriate for this patient (pre-med, induction, maintenance, and analgesia)
Pre-med: Pethidine or Ket/Val
Induction: Propofol or Alfaxalone
Maintenance: Isoflurane +/- Lidocaine for arrhythmias
Analgesia: ??
Caution: NO Acepromazine and NO NSAIDs
A 6-year-old red setter presents with retching and a distended abdomen, x-rays confirm a gastric-dilation-volvulus, what post-operative management is needed for this patient?
- IV fluids for 24-48 hours
- Monitor ECG for arrhythmias
- Monitor acid-base status
- Provide Gastric protectants
A 5-week old puppy requires surgery for a cleft palate correction, the puppy is bright but has ‘snuffly’ sounds, what are the important pre-operative disorders and considerations before going into surgery?
- Hypoglycemia
- Hypothermia
- Poor fluid regulation
- Underdeveloped hepatic function
- Poor CVS responses
- Aspiration pneumonia
- Pyrexia
- Dehydration
A 5-week old puppy requires surgery for a cleft palate correction, the puppy is bright but has ‘snuffly’ sounds, what actions can be done to minimize the pre-operative disorders that are present?
DO NOT FAST
- Give IV fluids +/- dextrose and monitor glucose levels
- Keep warm
A 5-week old puppy requires surgery for a cleft palate correction, the puppy is bright but has ‘snuffly’ sounds, what major complications may occur during anesthesia/ surgery and how can these be treated?
- Ensure ET tube is secure
- Monitor glucose q30mins
- Maintain HR (sympathetic NS is underdeveloped): Atropine
- Keep warm at all times
- AVOID long-acting drugs or those that require extensive hepatic metabolism
A 5-week old puppy requires surgery for a cleft palate correction, the puppy is bright but has ‘snuffly’ sounds, what anesthetic protocol is most appropriate for this patient (pre-med, induction, maintenance, and analgesia)
Pre-med: BZD + low dose Pethidine (e.g. Midazolam + Pethidine IM)
Induction: Propofol or Alfaxalone
Maintenance: Isoflurane or Sevoflurane
Analgesia: palatine nerve block with lidocaine
Caution: NSAIDs are NOT indicated for puppies under 6 weeks old
A 5-week old puppy requires surgery for a cleft palate correction, the puppy is bright but has ‘snuffly’ sounds, what post-operative management is needed for this patient?
- Fluids
- Keep warm
- Maintain BG +/- esophageal or gastric tube feeding
