Anaes Flashcards
What does LMA stand for and what is it
Laryngeal Mask airway, a supraglottic airway device
Most common drug used for Total IntraVenous Anaesthesia(TIVA)
Propofol
Why it is important to know where the spinal cord ends
For spinal blocks, has to be done below where the spinal cord ends
Where spinal cord ends in adults and children
Adults: L1
Children: L2-L3
Possible complication of a spinal block
Post Dural Puncture Headache/ Spinal headache, 1-3% chance
Risk Factors for post Dural Puncture Headache
1) Young Patient
2) Female
3) Pregnant
4) Large needle gauge
Antidote for Malignant Hyperthermia
Dantrolene
Most common anesthetic agents causing Malignant Hyperthermia
Inhalational agents
Anesthetic agents that are more likely to cause Malignant Hyperthermia
Inhalational agents eg sevaflurane, desflurane as well as succinylcholine
What to give the patient to reduce the likelihood of postoperative nausea and vomiting
IV metoclopramide or IV ondansetron
Why is it important to ask for hx of recent URTI
Recent URTI may predispose to peri operative bronchospasm
Function of bite block in supra glottoc airway
Prevent negative pressure pulmonary edema
5 ways of confirming ETT placement
DIRECT VISUALISATION
Misting of ETT
Equal chest rise
5 pt auscultation
End tidal CO2 indicator
Scoring for supine Laryngeal view scoring
Cormack Lehane grading
Normal range of Biospectral Index(BIS)?
40-60
Causes of Respi distress post thyroidectomy
- Neck hematoma
- Acute hypocalcemia from parathyroids
- Vocal chord palsy from RLN injury
- Tracheomalacia from long-standing goitre
- ?
Difference between phenylephrine and ephedrine
Phenylephrine causes vasoconstriction and either normal HR or bradycardia
Ephedrine causes vasoconstriction and tachycardia
Antidote for rocuronium(non depolarising NMBA)
Sugammadex
Definitive Mx for difficult airway with repeated failed intubation attempts
Surgical Cricothyroidotomy/front of neck access
Triad of anaesthesia
Hypnosis, Muscle paralysis and Sedation
Pharmacokinetics vs Pharmacodynamics
Kinetics: What body does to the drug
Dynamics: What drug does to the body
Rough number of half lives taken to fully eliminate a drug
5 half lives( About 96% cleared)
Sites of drug elimination in the body
liver, Kidney and lungs
Alternative types of fentanyl that tend to act faster
remifentanil and sufentanil
Elements of PONV score
What is MAC
Minimum Alveolar Concentration, the concentration of an inhalational agent at which 50% of patients will not respond to a painful stimulus
Durations of fasting
Clear feeds: 2hrs
Light meal: 6hrs
Heavy meal: 8hrs
Ideal BIS range for adequate anaesthesia
40-60%
Scoring system for PONV( Post Op Nausea and Vomiting)
Apfel score
1.Female Gender
2. Non smoker
3. History of PONV or motion sickness
4. Post op opioids
5 most common drug classes used to provide balanced anesthesia
Benzodiazepines
Opioids
Induction agents
Neuromuscular blockers
Sympathomimetics
Diastolic BP cutoff associated with periop MI
DBP>110
Ladders of pain control
Paracetamol
Nsaids
Opioids(Fentanyl, Oxycodone)
+-Adjuncts eg Pregabalin, Gabapentin
Common analgesics used for peri and post operative pain mx
IV paracetamol
Fast acting opioids: Fentanyl
Ultra fast acting opioids: Alfentanil,sufentanil, remifentanil
Long acting opioids: Oxycodone, Morphine
5 main drugs used in balanced anaesthesia
BZDs
Opioids
Induction agents
NMBAs
Sympathomimetics
Commonly used induction agents
Propofol
Etomidate
Ketamine
Thiopental
Volatile inhalational agents
Examples of volatile inhalational agents
Desflurane and sevaflurane
What does MAC stand for and it’s meaning
Minimum Alveolar Concentration
Concentration of volatile inhalational agents at which 50% of patients will not have a skeletal muscle response to a surgical incision
Ways of measuring depth of anaesthesia
BIS(Processed EEG)
End tidal concentration of inhalational agent
Examples of depolarising NeuroMuscular Blocking Agents(NMBA)
Succinylcholine
Examples of non depolarising NMBAs
Rocuronium,Atracurium
NMBA of choice in rapid sequence intubation
Succinylcholine depolarizing NMBA due to its faster onset of action and shorter duration
Reversal agent for non depolairisng NMBAs
Neostigmine
Contraindications for Succinylcholine use
Risk of HyperK
Burns victims
Denerving injury
Hx of Malignant Hyperthermia
Pseudocholinesterase deficiency
Ropivacaine vs Lignocaine
Lignocaine is shorter acting
INR cutoff for proceeding with central neuroaxial block
INR must be <1.5
Treatment for negative pressure pulmonary edema
Continuous positive airway pressure (cPAP)
Most common cause of hypotension in PACU
Hypovolemia: Hemorrhagic shock or dehydration
Most important principle in pain management
Multimodal analgesia
-paracetamol
-NSAIDs
-Opioids
-Adjuncts
-Nerve blocks
Antidote for opioid overdose
Naloxone
Example of cholinesterase inhibitor
Neostigmine
advantage of using etomidate as induction agent
Minimal cardiovascular effects, less likely to cause hypotension
Target intra op MAP
> 60
Target intra op temp
35-36 deg
Target intra op urine ouput
0.5ml/kg /hr
Side effects of etomidate
Adrenal suppression, high risk of PONV, myoclonus
Best induction agent for RSI
???
Ketamine if pt is not catecholamine depleted
Major concern in knee dislocation
Popliteal artery injury
Triple therapy for neck fasc
Penicillin G, clindamycin and ceftazidime
Clindamycin especially impt due to its anti toxin effect
Pre op fasting period
Heavy meals: 8hrs
Light meals: 6hrs
Breast milk: 4hrs
Clear feeds: 2hrs
Side effects of volatile inhalational agents
- PONV
- Malignant Hyperthermia
- HyperK
Reversal of Succinylcholine
Neostigmine+glycopyrrulate
