APIC Flashcards
What receptor are neuromuscular blockade drugs specific for?
nicotinic acetylcholine receptor
Where does the trachea begin?
At the level of the thyroid cartilgae C6
What level dose the trachea bifrucate
T5
When to suspect difficult bag mask ventilation
BONES Beard Obesity/ Obstetrics No teeth Elderly Sleep Apnoea
Proper positioning for intubation
“sniffing position” : flexion of lower C spine (C5,6), i.e bow head forward and extension of upper C spine at atlanto (C1) - occipital joint, ie. nose in the air
aligns the 3 axes of mouth, pharynx and larynx to allow visualisation from the oral cavity to the glottis
proper position for laryngoscope tip to visualise cords is in the epiglottic vallecular
contraindicated in known/ suspected C spine fracture/ instability
Differential Diagnosis of Poor bilateral breath sounds after Intubation
DOPE Displaced ETT Obstruciton Pneumothorax Esophageal intubation
ASA Classfication
1: Normally healthy
2: Mild systemic disease, but with no limitation of activity
3: Severe Systemic disease that limits activity; not incapacitating
4: Incapacitating systemic disease which poses a threat to life
5: Moribund. Not expected to survive 24 hour even with operation
6: Braindead patient whose organs are being removed for donor purposes
State which stage of anesthesia each of the following descriptions refers to? Delirium; violent behavior; increased blood pressure; increased respiratory rate; irregular breathing
rate and volume; amnesia; retching and vomiting with stimulation; disconjugate gaze
Stage II (excitement)
State which stage of anesthesia each of the following descriptions refers to? Depression of vasomotor center; depression of respiratory center; death may occur
Stage IV (medullary depression)
State which stage of anesthesia each of the following descriptions refers to? Eye movements cease; fixed pupils; regular respiration; relaxation of skeletal muscles
Stage III (surgical anaesthesia)
State which stage of anesthesia each of the following descriptions refers to? Loss of pain sensation; patient is conscious; no amnesia in early part of this stage
Stage I (analgesia)
Give Examples of inhaled anaesthetics
sevoflurane; desflurane; nitrous oxide;
isoflurane; enflurane; methoxyflurane Halothane;
With regard to inhaled anesthetics, what does MAC stand for?
minimum alveolar concentration
What is MAC in regard to inhaled anesthetics?
The concentration of inhaled anesthetic required to stop movement in 50% of patients following a surgical stimulus; a measure of potency for inhaled anesthetics
Which inhaled anaesthetic has the largest MAC?
Nitrous oxide
Which inhaled anaesthetic has the smallest MAC
Halothane
As lipid solubility of an inhaled anesthetic increases, what happens to the concentration of inhaled anesthetic needed to produce anesthesia, that is, does it increase or decrease?
Decreases
What is the blood/gas partition coefficient?
The ratio of the total amount of gas in the blood relative to the gas equilibrium phase. It refers to an inhaled anesthetic’s solubility in the blood.
Are MAC values higher or lower in elderly patients
Lower
Are MAC values higher or lower when opioid analgesics and/or sedative hypnotics are used concomitantly?
Lower
What is the role of the periaqueductal gray matter?
Primary control centre for descending pain modulation
enkephalin?
endogenous opiod neurotransmitter
Substantia gelatinosa
where the first order neuron of the spinothalamic tract synapses n
Do inhaled anesthetics increase or decrease the response to Pco2 levels?
Decrease
what characterises malignant hyperthermia?
Hyperthermia; muscle rigidity; acidosis; hypertension; hyperkalemia
Should a patient with a family history positive for malignant hyperthermia be concerned?
Yes, because a genetic defect in ryanodine receptors may be inherited.
What inhaled anaesthetic can cause hepatotoxicity
Halothane
What inhaled anaesthetic can cause nephrotoxicity?
Methoxyflurane
Which inhaled anaesthetic can be a proconvulsant
Enflurane
What inhaled anaesthetic can cause expansion of gas inside a closed body cavity
Nitrous oxide
What does thiopental do to cerebral blood flow
Decreases it
What does ketamine do to cerebral blood flow
Increases it
Why is more local anaesthetic needed in infected tissue?
Infected tissue has low ph
Anaesthetics become charged and cannot cross the membrane effectively
What is the order of sensory loss with local anaesthetics
Pain, temperature, touch, pressure
Which local anaesthetic can cause severe cardio toxicity
Bupivacaine
Which local anaesthetic can cause arrhythmias
Cocaine
What do you use to treat malignant hyperthermia
Dantrolene
Mechanism of succinylcholine
Strong Ach receptor agonist
Mechanism of Dantrolene
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle
What is the mechanism of non depolarising neuromuscular blocking drugs
Competitive antagonist of AcH receptor
Name the non depolarising neuromuscular blocking drugs
Rocuronium, mivacurium, vecuronium, tubocurarine, pancuromium
Complications of succinylcholine
Hypercalcemia, hyperkalemia, malignant hyperthermia
Describe the phases of succinylcholine in neuromuscular blockade
Phase 1: prolonged depolarisation
Phase 2: repolarised but desensitised
Side effects of local anaesthetic
CNS excitation
Hypertension
Hypotension
Describe how tertiary amine local anaesthetics act on sodium channels
Penetrate membrane in the uncharged form then bind to ion channel in charged form
What is malignant hyperthermia?
hypermetabolic disorder of skeletal muscle
due to an uncontrolled increase in intracellular Ca2+ (because of an anomaly of the ryanodine receptor which regulates the Ca2+ channel in the sarcoplasmic reticulum of skeletal muscle)
Inheritance of malignant hyperthermia
Autosomal dominant
What drugs can trigger malignant hyperthermia?
All inhalational agents except NO
Muscle depolarising agents - Sch
Signs of malignant hyperthermia
unexplained rise in ETCO2 increase in minute ventilation tachycardia rigidity hyperthermia (late sign)
