Tests Flashcards
List 6 NB differences between the paediatric an adult a/w?
Large tongue High pharynx Long, narrow epiglottis Narrow cricoid rings Short trachea Anteriorly angled vocal chords
List 5 symptoms or signs of an acute attack of porphyria?
Acute NB bcuz can lead to life threatening rxns to certain drugs:
Autonomic NS dysfunction :
Abdominal pain, V, nausea, HTN, tachycardia
Peripheral neuropathy:
Resp muscle paralysis, flaccid quadriparesis
Bulbar involvement:
Resp dysF, aspiration
Cerebral involvement:
Anxiety,mental depression/agitation, coma
Other: dark urine, hypo- ( Cl,Na,K) inappro ADH secretion
List Ix for general anesthetic cesaerian section?
Think mom and baby
Severe fetal distress Low platelet count Maternal hypovoleamia Placenta preavia Severe stenotic valvular lesions Cyanotic congenital cardiac conditions Anatomical anomalies & prev lumbar surgery Septiceamia Local sepsis
Contra Ix for ketamine?
Raised ICP Psychiatric Px Raised IOP or open eye surgery Situations of incr. O2 demand are undesirable - HTN - tachycardia
What is meant by train of four (TOF)?
Fade?
ToF: 4 twitches, 2 sec apart Measuring neuromuscular function: NDMR Ratio between Last and first contraction Induced by Peri N stim = whether NMB is still functional - ratio of 0.8 then resp muscle recovered.
When 4th twitch absent = 75% blocked
3rd = 80% block
2nd = 90% block
75- 90 % for Sx procedures
Fade: if present - ND block of 75%
Gradual diminishing of evoked response during prolonged/ repeated nerve stimulation
Also positive feed back mech of Ach (presynaptically) blocked by muscle relaxant.
5 conditions which may prolong the duration of action of suxamethonium?
Atypical psuedo-cholinesterase (genetic) - less affinity for sux = leads to scoline apneoa
Other ND drugs -usually helps with fasciculations
Opiate, inhalation agents
Hypothermia
Phase 2 block -high doses and also def. Pseudocholinesterases
Ramsay sedation scale:
Indication of pt responsivenss under sedation
Awake - pt anxious or agitated or both. 1
Levels: -pt cooperative, orientated, tranquil. 2
- pt responds to commands only. 3
Asleep - brisk repsonse to ligh glabellr tap. 4
Levels: - sluggish response 5
- no response. 6
With the aid of graph- show effect of arterial hypoxemia on the minute ventilation in an awake pt and a pt subjected to general anesthetic?
X- axis : PaO2
Y- axis : minute vol
Negative exponential line for normal
Much lower line = lower minute volume for hypoxeamia
So in essense Normally we will compensate for drop in PaO2 by increasing minute ventilation (increase rate of breathing)… This we pick up by the rising CO2 levels in the blood.
But when ventilated this reflex is lost en the patient becomes hypoxic due to the hypoventilation - Her we can rather up the PaO2 to 40 % in the recovery room.
Explain autoregulation and review the graph:
Autoregulation maintains a constant blood flow b/w certain pressure.
Once parameters exceeded, flow will become pressure dependent - leading to inadequate oxygen delivery / increased pressures.
The shift is 25 % outside of the normal autoregulation curve.
Either need to postpone Sx for 6 months to get bp contoled or if emergency ( cant wait )
sx can cont but…
The hypertensive pts BP must be maintaned within 25% of original pressure to prevent drop in flow.
List criteria that must be achieved before pt can be d/c after conscious sedation?
Full mental recovery
Not within 2 hours of admin pharm. antagonist
Vitals to normal:
Arterial sats preop value on room air
Pulse and BP within 10% of preop value
No orthostatic hypotension ( below 20% decr. Acceptable)
Patient: Walking, not dizzy Void urine No N /V Adequete pain relief
Patient must have responsible adult picking up
Not driving or operating machinary for a day
Contact number of dr.
With re to peri operative fluid therapy:
- Fluid requirements are calculated acc. to 4,2,1 rule. How much fluid would a 40kg person require ? (ml/ hr)
- What is the aim of peri operative fluid management?
- Name the most common electrolyte abnormality in the post op period?
- 4x 1-10kg ; 2 x 11-20kg ; 1 times >20kg
40+20+ 20 = 80ml/hr - Replace deficit ; supply maintenace fluid; restore
losses
AIM: maintain
Circulation
Normal serum electrolyte concentrations
Normoglyceamia - HypoNa
Which of inhalation anesthetic agents are metabolised most by the liver?
Name hepatotoxic metabolite formed during the metabolism of the above IAA?
To which disorder can this metabolite lead?
Halothane
Trifluoroacetyl-moiety
Halothane hepatitis
List the cuff requirements to accurately measure BP on the arm?
Inflatable cuff with pressure gauge
Diameter of upper arm + 20%
(Generally 14cm in adult)
Minumum req for monitoring circulation during anesthesia?
ECG
BP and HR every 5 min
Other monitor (clinical or invasive)
How can you determine whether a pts muscle strenth is adequate after reversal of NMB?
What are the clinical signs to look for?
Type of nerve stimulators?
Clinical signs
Nerve stimulator
Sustained hand grip Head lift > 5 sec Able to touch nose Clench tongue depressor b/ teeth MIP > 20 cm H2O Vital capacity > 15ml/kg No paradoxical mvmnt
Single twitch / ToF/ double burst / post tetanic twitch count
What monitor can be used to Ix the depth of anesthesia (hypnosis)?
Clinical signs
Processed electrocephalogram
Geudels levels of anesthesia
Bisprectral index BIS
Entropy monitoring
Auditory evoked potentials
Somatosensory evoke potentials
What is a capnograph?
A monitpr that measure the end tidal CO2 thus the carbon dioxide at the end of each resp cycle.
List the drugs that can be used in the preop period in a pregnant woman to reduce the risk and results of aspiration of stomach content during C/S?
Sodium citrate
Metoclopromide
Oral ranitidine
How would you medicate an anxious 5yr old who req GA?
Midazolam/ lorazepan
Possible CI for administering sedative premedication to pt?
Infants/ elderly Frail/ debilitated Decr. LOC Intracranial pathology -ICP A/w obstruction Severe Lung disease/resp distress Hypovoleamia / shock
List 5 neurotransmitters involved in N and V and a pharmacological antagonist?
Explain combination anti emetic therapy for prophylactic PONV?
Will ginger root be effective for PONV?
Dopamine - droperidol. (D2) - NV caused by opiods and CI in pt with already prolonged QT interval
Metoclipramide- ineffective for prophylaxis PONV
Ach - hyoscine hydrobromide/ scopolamine (muscurinic) - opiod induced vomiting - sfx are sedation, comfusion, dry mouth
Histamine - cyclizine, promethazine (H1) - middle ear surgery - IV leads to tachy and hypotension.
5- Ht (serotonin) - granisetron, ondansetron (5HT3) - headch and GIT upset - replaced cannabis in cancer pt nausea
Antidopaminergic (extrapyramidal sfx)
Anticholinergics
Antihistamines( extrapyramidal sfx)
Antisertonergic
Other:
Encephalins (opiod r)
Substance P ( neurokinin 1 r) - antagonist :
Aprepitant
also steroids: dexamethasone
it is better to use 2 antiemetic drugs that work on 2 different receptors. Antisero and antidopa OR antisero and steroid.
no
Principle of a vaporizor?
FGF thru the vaporisor
Part is diverted to the vaporisor
Part bypasses (splitting ratio)
Diverted part is shunted through anesthetic vapor and meets up again with bypassed portion when it is then admin to pt.
Cooling is prevented by keeping a constant vapour pressure of 1- 10 cm H2O
What will you take into consideration when deciding how to manage a diabetic pt for surgery?
Type of surgery
Medication the pt is on
Blood glucose control of pt
Define pain?
What is a nociceptor? nociceptive?neurogenic?
Plasticity?
Hyperalgesia?
Windup? Allodynia?
Neurogenic and Neuropathic pain?
Chronic pain state?
Anelgesia?
Unpleasant sensory and emotional experience
Ass with actual or potential tissue damage
Neuroendocrine phenomena
just because you cannot comm verbally does not mean you do not feel any pain.
The emotional component determines the perception to pain.
pain receptor which is sensitive to preferentially a noxious stimulus.
Acute pain 2dary to tissue damage
Chronic pain due to structual/functional damage to nerve.
Pain pathway is greater/lesser than intensity of stimulus.
Sensation is experienced as excessive and out of proportion to stimulus.
Primary :at site of injury (cytokines, neurotrans…)
Secondary: hyperexcitability of spinal nerves.
Repetitive C firbe stimulation leads to prolonged dorsal horn activity.
Pain due to stimulus that does not normally provoke pain.
Pain due to primary lesion / dysfunction in peripheral/ central nervous system.
Pain that cont. after tissue damage has healed.
State where you feel no or little pain to otherwise painfull stimulus.
Define hyperalgesia?
allodynia?
Sensitized C- fibres
Pain receptors dont adapt, but become hyper- excitable
Increased response to stimulus that is normally painfull.
Pain experienced both from site of injury and from surrounding tissue (allodynia) - pain due to stimulus that normally does not provoke pain.
Define primary and secondary hyperalgesia?
Primary:
Changes that occur at site of injury - tissue
damage and inflammation
Secondary:
Hyperexcitability of spinal neurons so that
previously innocuous stimuli are now painfull
Define windup?
When best to rx and what complx if not rx adequately?
Prolonged dorsal horn activity after repetitive C fibre stimulation.
Rx acutely- easier to mx pain
Chronic refractive pain
Re pre operative fasting:
list the NPO rules:
Min fasting periods: in hours
- Clear fluids. 2
- Breast milk. 4
- Formula milk. 6
- Non-human milk 6
- Light meal. 6
- Fatty meal. 8
Define what is meant by
Light meal and clear fluids?
Clear fluids: Black tea / coffee Fruit juice w/o pulp Carbonated drinks No alcohol
Light meal:
Liquid and toast
List the factors that delay stomach emptying?
Pain, stress, anxiety Opioids Vagotomy Fatty meal Pregnancy Diabetes GIT obstruction
T/F:
- Latrodectism is a syndrome caused by the release of peripheral neurotransmitters such as ACh and NorA. Also GABBA (Lactrodectus spider- black widow)
- Morphine is potential poison with high inherent toxicity.
- The clinical picture of acute organophosphate poisoning is comparable to that of effects of neostigmine.
- Cocaine causes pronounced peripheral vasodilation.
- Obidoxime - is a cholinesterase reactivator
- The most serious types of mushroom poisoning present with sx and signs within 6 hours of ingestion.
- Boomslag venom causes a prolongation of clotting time, leading to bleeding complications 6-24hours after an effective bite.
- Scombroid poison develops after ingestion of fish of which the cold chain has been broken.
- Saxitoxin is the cause of paralytic shellfish poisoning.
- Theophylline poisoning is usually ass with severe hyperkaleamia.
- True
- False
- True - both inhibit cholinesterases
- False - vasoconstrictor
- False
- false - after 6 hours
- True
- True
- True
- False - HYPOkaleamia
List negative features of etomidate (5 Bs)
(IV induction agent)
incr. affinity of GABBAa receptor for benzodiazepines
Can also inhibit plasma cholinesterases.
Hypoalbunimic states- effects are much higher.
dos NOT have anelgesic properties, only LOC
Almost no effect on circulation
Best for hypersensitive pt.
Braak. - emetogenic Beweeg - movement upon injection Baie duur - expensive Brand - burns on injection Bynier - adrenal supression
List complications of suxamethonium?
Short acting muscle relaxant (within 60 sec for 12-16 min)
DMR = ass with fasciculations (bind to nic-R)
Not inactivated by cholinesterases.
Once in blood - removed by plasma cholineesterases.
Prolonged action because of reduced plasma cholE:
Pregnancy, hepatic disease, burns, malnutrition
Bradycardia (Ach, rx: prior atropine/glycopyrulate)
Hyperkaleamia (arrythmias/cardiac arrest) - can be used immediately after but not after 48 hrs)
Incr IOP, (sustained contraction of extra ocular muscle)
ICP ( PaCO2 due to fasciculations)
Masseter muscle rigidity COMMON
Fasciculations ( can be prevented)
Anaphylaxic rxn Scoline apnoea( due to genetic def / absence of enz - longer duration of action)
Malignant hyperthermia :
Hypercapnia, tachycardia, hyperthermia, metAcid