Test_C Flashcards
T/F:
- During sepsis, there is 30% temporary depression of the myocardial contractility.
- During sepsis the lung water is increased
- During SIRS, the WBCC is more that 12000 or less than 4000.
- Viral infection can cause SIRS
All true
Name an example of a benzodiazepine?
List 4 effects of benzos that are usefull in premedication?
Midazolam
Anxiolysis - amnesia
Sedative hypnotic
Anticonvulsant
Midazolam can be used to induce anesthesia
List 3 sfx of benzos?
CNS depression - APNOEA in overdose
Tolerance and dependance
AGITATION/CONFUSION in elderly
Impaired motor function (coordination)
What is the mechanism of action of benzos?
GABA agonist - incr the inhibitory stimulation of CNS
Name 5 ways to confirm the correct placement of the ETT?
Auscultate : bilat breathing
Visualization: chest mvment, also ETT thru vocal cords
Water vapour in mask, O2 sats normal, CXR
Capnography
Regular, sustained, non declining
Re to:
Cerebral metabolic rate
Cerebral blood flow
ICP
What affects will the following drugs have:
- Thiopentone
- Ketamine
- Isoflurane
- N2O
- All decr
- All incr
- Decrease met rate, incr other
- All incr.
4 groups of pt at high risk for PONV?
Females
Non-smoking
Opioids use
Prev Hx / motion sickness
Name 5 neurotransmitters involved in in N and V an give pharmacological antagonist.
Serotonin (5HT) - ondansetron Histamine (h2) - promethazine, cyclizine Dopamine. - droperidol, metoclopromide Ach - hyoscine hydrobromide Substance P - antineurkinin 1 - aprepitant
Which two a/w problems can obese pt get?
Limited mvmnt of atlanto-occipital joint -/+ TMJ
Decr thyromental distance
List 5 effects with re to effects/ actions of IAA ass with aging?
MAC decr by 4 % / decade after 40
Onset of action
- accelerates - CO depressed
- decreases- VQ abnormalities
Myocardial depression due to drugs accelerted
Prolonged recovery time ( incr volume of distribution and decr. gass exchange)
Halothane metabolism decr by liver thus longer acting
Name al IAA in increasing order acc to their Min Alv Concentration?
Halothan Isoflurane Enflurane Sevoflurane Desflurane N2O
How do local anesthetics work?
Prevent the flow of Na through the Na channels, thus preventing action potentials
Which 2 organ system are particularly affected by LA?
CNS and CVS
What are the precautions to prevent Sfx of LA?
Dont exceed prescribed dose
Limit dose used in vascular areas of body
Always aspirate before injecting to exclude IV placement
Test dose - which contains adrenaline as a intravascular marker should be given before main bolus dose : helps ID the intravascular placement of needle
T/F: RSI
- Is routinely used in elective surgery.
- Indicated in elective surgery when stomach in full
- Indicated in emergency surgery when stomach suspected to be full
- Indicated during elective C/S where the mom refuses regional anesthesia and mother has been starved for 8hours
- Is contraindicated in children who have full stomach - because they have difficult a/w.
- False
- True, aspiration risk
- True
4. - False
T/F: recognition of a difficult a/w
- Mallampati score I
- Thyromental distance is 6cm
- Mandibular teeth cannot slide anteriorly to reach the maxilary teeth
- Pts head cannot extend sothat the chin is higher than the occiput in a standing/ sitting position.
- False only 3 and 4
- True (normal > 6.5 cm)
- True
- True (delikans signs)
Nb concept:
Raised BP in pt with cardiac failure must first be Rx before anesthesia - why?
Normal heart is insensitive to afterload,
A myopaths heart is extremely sensitive to this.
THUS
A rise in BP increases the afterload, increased afterload will decrease the SV
CO = SV x HR thus CO will also decr
NB SV determined by
Preload, after load and contractility
T/F: re drug interactions in anesthesia
1. Synergistic drug rxns are those where one drug counters the effect of the other drug
- Anesthetic drug interactions can be beneficial to the pt.
- Opioids antagonizes the effect of induction agents by up to 65%.
- The interaction bw N2O and IAA is synergistic
- Interaction bt thiopentone an midazolam is synergistic.
- False
- True
- False
- True
- True
Name the CVS CI for spinal anesthesia?
Hypovoleamia
Stenotic valves
Constrictive pericarditis
Abnormal clotting profile
What is the average blood volume of an adult?
75 ml/kg
How would you manage more than 40 % blood loss?
Replace the blood loss with equal volume of transfused blood (as for 20-40% loss)
Add platelets and clotting factors
Name 5 factors that affect the liver blood flow during anesthesia? LBF
What 2 IAA preserves LBF?
Even though GA and extensive regional anesthesia cause a fall in O2 consumption the fall in LBF is much more and of grave importance.
Intra abdominal surgery -fall a further 50%
Incr venous pressure - decr. Venous outflow
PEEP and IPPV -decr CO and invr venous press.
Incr PaCO2, incr in Symp stimulation, incr symp tone.
All IAA
NB : halothane, nitrous and enflurane cause arterial resistance incr (hepatic and mesenteric) AND dcr in portal venous outflow
Sevoflurane and isoflurane - prserves hepatic artery inflow
How to manage MH:
Specific
Non- specific
C SSHHARP D
Specific:
- Dantroline sodium 2-3 mg/kg bolus every 5 min
Untill sx revert
- max dose = 10mg/kg
- SFx : muscle weakness, phlebitis
Non-specific: -stop IAA (trigger) admin 100%OXYGEN - sedation /TIVA - cooling measures: cold IV, NG lavage, Bladder lavage, abdominal lavage -hypercarbia (incr. minute ventilation) - asidosis : Rx and monitor (bloodgas) - hyperK - renal damage: prevent (fluids for duiresis) - postop : ICU/ HCU
Choose IV induction agent best suited and CI in following pts:
- Shocked pt
- Hypertrophic cardiomyopathy
- Porphyria
- Asthma attack
Best; CI
- Ketamine ; thiopentone
- Etomidate; ketamine
- Propofol ; thiopentone
- Ketamine ; thiopentone
Consider IAA:
Halothane, sevoflurane , N2O, isoflurane
- Highest MAC
- Best in children
- CI in pt with possible pneumothorax
- CI in pt with fam Hx of MH
- CI in pt with liver disease
- N2O
- Sevoflurane
- N2O
- All
- Halothane
How are the effects of suxamethonium terminated?
Plasma pseudocholinesterases
Name two conditions that can lead to prolonged action of sux?
Burns
Pregnancy, previous dx
Why should GA be avoided in child with previous URTI?
Incr risk of desaturation Apnoeic spells Broncospasm Laryngospasm Excessive coughing
List two rx modalities for LA toxicity?
Intralipid (1.5ml/kg followed by infusion )
Rescuss (ABC)
Continue CPR (one of the reversible causes)
Terminate convulsion (benzo/thiopentone)
4 levels of sedation
Also what stimuli necessary to arouse pt.
Level 1: anxiolysis - no stim req
Level 2: conscious sedation - verbal and tactile
Level 3: deep sedation - painful
Level 4: GA - pt cannot be aroused
6 medical conditions ass with obesity?
HTN IHD NIDDM Gallstones OA DVT Peripheral vascualr disease (embolus) Cerebrovascular disease (stroke)
What factors determine end tidal CO2?
Body temp
Cardiac status
Pulmonary disease
Normal capnograph trace
If all stable the end tidal should = that of PaCO2
4 ways to decrease venpus pressure in brain?
15 deg head up position
Neutral head position
No jugular compression
Limit intrathoracic pressure
Limit PEEP, avoid coughing, avoid aw obstuction
Avoid, rx pneumothoraxWhat does an increase in PaCO2 do to cerebral blood flow?
It increase it
What an increase in PaO2 do to cerebral bloodflow?
Decreases it
Where does ach act as neurotransmitter in PNS
Also mention the receptor
NMJ - nicotinic
Autonomic ganglia - nicotinic
Postsynaptic para$ - muscurinic
Sweat gland -muscurinic
How will you know that your rescuss effort is creating a reasonable circulation?
Using a capnograph
Reading needs to be > 1% and needs to be maintained
Explain diffusion hypoxia?
How is it remedied?
30 min after Pa N2O breathing -large potions dissolved in blood and tissues even tho solubility is low (HISND)
If pt suddenly switched to room air - a sequence of events dilute the oxygen leading to hypoxia
( as PaN2O decr rapid diffusion from pulm veins to alveoli will take place- thus filling lungs)
Administer oxygen enrished mixtures (50-100%) first few minutes after admin N2O
When would you administer steroid for post op management?
Steroid therapy currently> 2/52
Steroid therapy in last year > 1/12
Steroid therapy high dose inhaled
(Beclamethasone)
Known adrenal insuff
Inadeq response to testing of axis (ACTH / stress)
Adrenal of pituitary surgery
What is the trendellenberg position?
Conseq
Dangers
When pts head is lower that feet during laproscopic surgery.
Conseq:
Increased :
venous return, right arterial pressure, central blood vol, and CO.
Reduction in:
FRC and lung compliance - pulm atelectasis
Dangers
Hypoxeamia
Nerve compression (brachial plexus inj)
Atelectasis
T/F:
- A max decr in BP of 35% (compared to preop pressure) can be tolerated by HTN pt.
- Intravascular volume in a pt with HTN is 15% greater than that of the normotensive pt.
- The higher resistance to bloodflow in the HTN pt is because of generalized arterial vasospasm.
- Beta adrenergic blockers will control/ prevent HTN ass with ETT in the HTN pt.
- False, 25%
- False, less
- False - due to smaller internal diameter, due to muscular changes
- False - alpha blockers will
