Anaesthesia and Analgesia Flashcards
What are the benefits of CRI vs bolus doses?
Avoids reliance on
signs of pain re
appearing.
Avoids disturbing
patients every few
hours.
Avoids peaks and
troughs of drug
concentrations
CRI vs bolus doses.
What is a steady state?
A steady state is where the rate of drug
administration is equal to the rate of drug
elimination
What equipment is needed for a CRI?
*Intravenous access
Peripheral vein usually appropriate
*May be in place for
several days
*Drugs either as stock solution or diluted
*Syringe driver or infusion pump
What is morphine and what is it used for?
*Opioid
*Pure agonist at mu receptor
*Gold standard analgesic
*Schedule II drug
*Cardiorespiratory effects
*Histamine release after IV administration
*Reduce rate for the cat
Morphine
What is ketamine and what is it used for?
*NMDA antagonist
Chronic pain conditions with hypersensitisation
*Good somatic (vs visceral) analgesia
*Sub-anaesthetic doses
*Cardiorespiratory effects
*Hallucinationary effects
What is lidocaine and what is it used for?
*Local anaesthetic
*‘Safest’ local anaesthetic to give IV
*Analgesic
*Anti-inflammatory
*Anti-endotoxic
*Pro-kinetic
*Cardio-respiratory effects
*Use in cats controversial
What is MLK and what is it used for?
*Morphine, Lignocaine, Ketamine
*Produces multi-modal analgesia
*Profoundly MAC sparing
*Reduce doses in recovery as may produce profound sedation
What are the super opioids?
*Fentanyl, alfentanil and remifentanil
*All pure mu agonists
*Schedule II drugs
*Usually used intra-operatively
*Produce respiratory depression
*May produce bradycardia
What are Medetomidine / dexmedetomidine?
*Alpha 2 adrenergic agonist
*Much lower doses used compared to sedation
and premed doses
*Cardiorespiratory effects may still be observed
How do you perform Buccal Mucosal Bleeding Time (BMBT)?
To perform this test, the dog is placed in lateral recumbency. A Surgicut® bleeding device
includes a spring-loaded blade designed to create a standardised 5 x 1 mm incision in the
oral mucosa (in cats the incision is 2.5 x 0.5 mm.) The site is chosen away from visible
blood vessels. Absorbent paper is used to blot away the blood by placing it 2 mm away
from the incision and performing this at five second intervals.
BMBT is the time taken from the initial incision to complete cessation of haemorrhage. In
general, both incisions stop bleeding at about the same time but if not the first one to stop
is recorded as be BMBT.
The normal ranges of be BMBT in dogs is considered 1.4 to 3.5 minutes and in cats less
than 4 minutes is considered normal.
This easy chairside test is poorly standardised and should be considered as a mere
indication of a potential breeding disorder. An increased BMBT could be an indication of
uraemia, lung worm infestation, Leishmaniasis, and Ehrlichiosis and DIC.
What may happen if secondary haemostasis is abnormal?
Activation of the coagulation cascade and fibrin formation stabilises the platelet plug and is
considered as secondary haemostasis. Abnormalities in this process is identified by
specific coagulation screening test, for example prothrombin time, activated partial
thromboplastin time, activated coagulation time, fibrinogen levels. Protein production
reduced in the absence of vitamin K or antagonism (PIVKA) and individual coagulation
factor assays, could indicate vitamin K deficiency.
Failure of secondary haemostasis in vitamin K deficiencies often leads to the formation of
haematomas, haemoabdomen, haemothorax or haemoarthrosis.
