anaesthesia of sicker patients

Question 1

What is the benefit of providing IVFT to ill patients prior to anaesthesia?

Answer 1

improves hypotension, reduces tachycardia and arryhthmias

Question 2

Give examples of perioperative preparation in ASA III-V patients

Answer 2

Pre-operative blood tests & diagnostics are indicated!
IVFT resuscitation
Anti anxiety medication may be indicated
Continue medications during peri-op period - prevent disruption to anaesthesia
Pre-place IV access
Pre-oxygenate (mask, flow by, cage, nasal prongs)
Drain chest/abdomen or decompress

Question 3

What blood tests are suggested prior to surgery in older and sick patients?

Answer 3

packed cell volume
total solids
electrolytes
glucose
urea and creatinine

Question 4

Describe pre-medication of ASA III-V patients

Answer 4

Avoid alpha 2 agonists (narrow therapeutic index) - can give low dose of dexmedetomidine if animal is distressed
Opioid maybe sufficient to sedate (e.g., methadone or butorphanol)
Ketamine + Midazolam (IM or IV) in cats (not in hypertrophic cardiomyopathy)
Low dose alfaxalone and opioid is an option (+ BZD)

Question 5

Describe the induction of anaesthesia of ASA III-V patients

Answer 5

Do not leave unattended after premed
Continue to provide oxygen
Induction drugs given soon after premed (IV premeds preferred)
Slow injection of induction agent (try to use as little as possible)
Keep finger on pulse during induction
Observe mucous membranes during induction
Be ready to intubate and secure airway to provide oxygen
Monitoring equipment before induction?

Question 6

Describe the maintenance and monitoring of ASA II-V patient anaesthesia

Answer 6

Continual monitoring
Avoid deep anaesthesia
PIVA and TIVA can reduce reliance on volatile agents
Analgesia + local blocks to reduce ISO
Emergency drugs ready
Keep warm - hypothermia big risk

Question 7

Describe the approach to sick horse anaesthesia

Answer 7

IVFT prior to anaesthesia
PCV, TP, lactate (identify anaerobic respiration), glucose tests, nasogastric tube
Still use alpha 2 agonist prior to ketamine - safety reasons
Comprehensive monitoring
PIVA is ideal - reduces ISO
regular blood gases
Careful positioning

Question 8

Describe the IVFT of sick horses prior to anaesthesia?

Answer 8

hypertonic saline used, quickly improves circulating volume (lower volume needed than Hartmann’s) - give isotonic solution as soon as on table to replenish water reserves