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
- tachycardiaWhat 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
List 5 advantage of a laproscopic technique over n open surgery?
Take note PONV problematic - give dexamethasone and ondansetron before ending surgery
- Pt position (trendelenburg)
- Insufflation with CO2
- Pneumoperitoneum and intra abd pressure ( threshold pressure
- Small incision
- Decr post op pain and discomfort
- Shorter hosp stay
- Early ambulation
- Less scar formation
Name 2 dangerous and 3 safe nesthetic drugs in a pt with porphyria?
GA: Induction Inhalation Neuromuscular Analgesia
Regional:
Dangerous: *Barbiturates( thiopentone) * Etomidate Enflurane rather not Pethedine rather not NSAID rather not Theoretically not lignocaine
Safe: Propofol N2O (halothane) All inhalants. Bupivacaine ( local anesthetics) NDMR and reversals Opiates and midazolam
Advantage and disadvantage of Entonox as anelgesic during labour?
Other ways for anelgesia:
Pharma and non pharma way.
Ketamine
Pethidine/ fentanyl / morphine
Epidural (gold standard)
Advantages: Pt can admin. herself Inexpensive No effect on labour process/ baby Ultra short acting
Disadvantages
Maternal hypoxia
Sedation
N and V
Define the MAC
Minimum Alveolar concentration:
Concentration at which 50% of subjects given the drug will not move in response to a specific painful stimulus.
Also the end point at which to measure and compare the potencies of IAA
List factors that can effect MAC:
Age. (Maximal at 6m, decrease by 6% per decade )
Body temp (if low MAC decr)
Pregnancy (decr. MAC)
Opioid / benzodiazepine co admin (decr. MAC) - ceiling effect.
Severe alteration in physiology (cardiac shock) decr it.
List 3 advantages of a Jackson rees mod of Ayer T piece / Mapleson F breathing system?
Allows spontaneous breathing Simple, lightweight, inexpensive Low resistance Minimal dead space No valves that can malfunction
Name 5 findings that would obligate you to postpone surgery in achild with a runny nose?
Children are obligate nose breathers, thus anything obstructing the nose can lead to compromised breathing
If pt had upper resp infection - laryngospasm can occur up to 6 weeks after that.
Child also rapidly desaturates:
Oxygen consumption. Twice of adult.
Alveolar ventilation higher due to increased RR ( tidal vol same as adult). - child falls and awakes quicker.
High Closing volume. Laryngospasm or loss of volume will lead to collapse/shunting.
Anatomic shunts. Right to left shunts due to patent ductus arteriosus due to increased presure in pilm artery. (Hypoxia,hypercarbia,acidosis)
List the 10 effects of opioids, mediated by their action on the CNS? 8
How to reverse rigidity? How to avoid?
What can be given if pt gets the shivers?
Other:
Anelgesia (supra spinal, spinal, peripheral)
Anesthesia (reduce MAC by 60-70% and less IV induction drug also)
Muscle rigidity (activ. Of kappa R)
Pupils (miosis) - opiod abuse
Thermoragulation threshold reduced - start shivering at lower temp than normal.
Euphoria (reduce anxiety, agitation)
Naloxone - give muscle relaxant pre
Pethidine
Resp depression
CVS(hypotension, bradycardia, cardiac depression)
GIT( NVC)
Pruritis
List 5 conditions that predispose to abnormal incr in serum K after admin of suxamethonium?
- Burns
- Trauma
- Muscular disease
- Neurological disorders
- Sepsis
- Immobolity
List the clinical features of supine Hypotensive syndrome during pregnancy?
Biggest problem of spinal anesthesia.
For a sensory block of T4 you will still get 2 levels higher sympathetic outflow block, leading to bradycardia which will potentiate the hypotension.
Early dx is of grave importance to prevent mortality.
Take bp /min for 20 min. Then / 5 min.
Comm to exclude dizziness and nausea which preludes hypotension.
use of fluid with vasopressor :
Phenylephrine: tachycardia, stenotic lesions, severe
HypoT Bradycardia Sweating Nausea Anxiety, dizziness Pallor
What is the cause of hypotensive supine syndrome in pregnancy?
How can one prevent this?
Aortacaval compression due to lying in the supine position after 20 weeks of pregnancy.
ALSO extended block of sympath fibres = venous and arterial dilation. And bradycardia.
Turn mom onto her left side and administer oxygen
Avoid lying in supine position after 20 weeks of pregnancy, rather left lateral position.
Admin crystalloids prior/during block to lower vasopressor needed to maintain systolic (100mmHg)
Colloids actually better but anaphalactic.
If PR slows give antocholinergic to inhibiy parasympathetic comtrol ( atropine)
Classify LA - local anesthetics and give 2 examples of each.
NB concepts:
Low pKa - rapid onset
More lipid soluble - slow onset and more potent
Esters.
- cocaine - procaine (slow onset, low potency) - tetracaine
Amide
- lignocaine (rapid onset, low potency) - mepivicaine (interm onset, low potency) - bupivacain ( slow onset, high potency)
T/F:
1. Tachycardia is detrimental to ischeamic myocardium.
- Tachycardia during mitral stenosis is beneficial to the CO.
- Beta adrenergic blockers must be stopped preoperatively.
- Beta adrenergic blockers prevent perioperative myocardial infarction.
- True
- False
- False
- True
Pt has pH of 7.2
BE of -7
Weighs 60 kgs
What is the equation that is needed to calculate the amount of bicarb needed to correct the acidosis.
How many ml of 4.2% NaHCO3 solution will be req in the pt above.
4.2% solution contains 0.5 mEQ/ml
Weight (kg) x BE x0.3 = mEq of bicarb req.
60 x 7 x 0.3 = 126 mEq and thus 326ml of 4.2% bicarb
What does SIRS stand for?
Systemic inflammatory response syndrome
MOD?
Multiple organ dysfunction
In septic shock there is myocardial suppression: on which day after the onset of septic shock is this at a max?
On which day will cardiac function be normal?
T/F: viruses cannot cause SIRS
Day 2
Day 10
False, they can
Re CPR T/F:
- Best speed for cardiac compression: 80-100pm
- Open cardiac massage is better than external cardiac massage.
- Asystole is initially rx with external defib.
- During VF there is a direct relationship bw neuro outcome and time before succesful defib.
- Calcium is used as a matter of routine in CPR.
- A capnograph is a good monitor of pulmonary blood flow.
- After cardiac arrest in hosp: 50% of pts will be d/c in good functional neuro outcome
- Excessive bicarb admin will result in metabolic alkalosis.
- Excessive bicarb admin will result in a resp venous acidosis.
- Adrenaline 0.5-1mg should be given IV every 3 minutes.
- Reversible causes of asystole? How to rx them?
- True
- True
- False
- True
- False
- True
- False
- False
- True
- True
- Hyperkaleamia - calcium chloride
Hypoxia - effective alv ventilation, 100%oxygen
Vagal compress( traction eye/abd organs) - release of stimulus and atropine
Other: Pneumothorax Cardiac tamponade Hypoglyceamia Acidosis
What does FRC stand for?
What is it?
How does GA affect FRC?
what induction agent does not cause effect on FRC?
Functional residual capacity = ERV + RV
Also allows for continues gas exchange
The sum of volumes remaining in the lung after normal expiration
Decr it by 15-20% but not progressive rather immediate (within minutes). - remains low for hours to days after anesthesia. Irrespective of breathing spontaneously, of ventilation, of muscle relaxant.
Not in sitting position.
Ketamine.
Which ventilation strategy will overcome the effect of anesthetics on FRC? Regarding capacity of lung and reserve.
What will this mean: V/q Compliance Vd/Vt A/w resistance
Minimum inspired oxygen of 30 % during GA.
Immediately postop. 40 % oxygen.
Preoxygentation - 100% oxygen thru tight fitting mask for 3 minutes.
Decr. - low PaO2
Decr. - incr. work of breathing
Incr. - incr. in PaCO2 and work
Incr -incr in work
Why will the pt wake up if the emergency oxygen is left open on the AM?
The emergency oxygen does not flow through the vaporisor and thus bypasses directly to the pt - diluting the final gas mixture and the anesthetic.
T/F:
1. Antihypertensive drugs must be stopped prior to surgery?
- Variation of 30% in BP during anesthesia (compared to the preop value) is acceptable.
- Autoregulation gives the relationship bw perfusion pressure an stroke volume.
- Uncontroled HTN will improve CO.
- False
- False 25%
- False - blood flow
- False
If a pt dies because of submersion - he dies due to fluid in the lungs - T/F?
False, drowning is due to hypoxia.
in 10-12% of cases the lungs are found to be dry as result of laryngospasm.
What is the single most important action you should do if a pt who suffered a near drowning accident is brought to your consulting rooms in an unconscious state.
Give 100% oxygen
Tabulate difference between sea and fresh water near drowning with reference to :
Serum K
Intravascular volume
Serum K. Intravascular vol
Fresh. Low. High
Sea. Normal/ high. Low
Name 3 joints that may be affected in an Diabetic pt that can lead to a problematic airway?
Temporomandibular joint TMJ
Atlanto-occipital joints AOJs
Cervical spine joints CSJs
A diabetic is well controled on short acting sulphonureum.
He must undergo large surgery, will you stop the medication and change to insulin sliding scale?
Yes-
Flow diagram:
Approach: Diabetic scheduled elective surgery
Control
- good
Minor ( cont oral rx)
Major ( periop 6 hourly short acting subcut
insulin sliding scale*)
- bad.
Minor *
Major *
Pt with non- ketotic hyperosmolar coma, Must undergo anesthesia. Weight: 70kg SerumNa: 152mmol/L What is his total fluid deficit?
Give formula used.
(Mass x 0.6) x(normal Na)/ (measure Na) = TBW
(Normal TBW for this mass) -( current TBW)= fluid deficit
Thus
(70 x 0.6) x (140)/(152)= 38.68L
(70x0.6)- 38.68 = 3.32L being the fluid deficit
List the minimum monitoring req that must be applied during anesthesia? 10
Standard 1
- Qualified dr.
- Dedicated to anesthetic care
- Present at all times
Standard 2
4. Must monitor ventilation, oxygenation,
circulation and temp continually. Ability must
Exist to measure NM function too.
Ventilation
Qualitative clinical signs
ETT/LMA - capnograph
Ventilator - disconnecting alarm
Oxygenation
Oxygen analyser with low O2 alarm
Pulse oximeter and pt color
Circulation
ECG
BP and HR every 5min
Other monitor(clinical or invasive)
List posssible causes of postop confusion in elderly pts?
DIMTOP
Drugs: anticholinergics, benzo, alcohol Infection Metabolic: hypoG, electrolyte abnormalities (Na) Trauma: hypoperfusion, fat embolism Oxygen: hypoxia, hypercapnoea Psychiatric - psychosis Pain
Write formula for calculating BMI and for ideal body weight?
At which BMI is one regarded as:
- Overweight
- Obese
BMI: weight/ height^2 Kg/ m^2
- > 25
- > 30
Name 3 types of nerves involved in pain:
A beta
A delta
C fibres
Define windup?
2 sites where it can occur?
Name neurotransmitters involved in windup?
Prolonged dorsal horn activity after repetitive C fibre stimulation.
Peripheral and
Dorsal horn of spinal cord.
Glutamate (excitatory amino acid)
Substance P
Calcitonin gene related peptide
Prostaglandins are released that increase neurotransmitters and aggrevates pain thru positive feedback.
Advantages and disadvantages of Halothane?
Adv:
Smells okay - inhalation induction
Bronchodilator
Disadv: Halothane hepatitis. HEPATOTOXIC Malignant hyperthermia Cardiac Sfx Postop N and V Suppress breathing response to hypox and hyperCapnia Myocardial supression
How will you minimize the risk of PONV?
ID high risk pt ( risk scoring)
Use two or more antimetics ( diff. Receptors)
Other
Minimize : intraop use of opioids
Neostigmine
Consider regional anesth. And adeq. Hydration.
Name 5 CI for regional anesthesia in C/S?
Also indications for GA in C/S.
Cardiac Obstetric Infection Coagulation Other * relative
Cardiac
HypoVol ; stenotic lesion(severe); cyanotic
congenital cardiac lesions
Obstetric
Severe fetal distress (fetal bradycardia)
Low platelets
Tabulate the advantages of Ayer T piece breathing circuit?
And disadv
Adv: Simple tubes, lightweight, can be coaxial Minimal DS No valves Low resistance to breathing Economical for controled ventilation Inexpensive Facilitates scavenging of waste gasses
Disadv:
High FGF during spontaneous breathing
If co axial: inner tube may disconnect or break
The entire tube space becomes DS - leading
to severe alveolar hypoventilation
Atmospheric pollution with IAA
Define third space losses?
At what rate must it be replaced?
Fluid loss as result of tissue oedema and transcell fluid displacement.
Functionally this fluid is not available to the vascular space - sodium rich fluid sequestered into damaged tissue.
Balanced salt solution is the best replacement and volume distribution correlates roughly with the degree of tissue manipulation and injury.
- intra abdo procedures with small incisions
= 2ml/kg/hr - major bowel resection= 5ml/kg/hr
What is the ideal HB value for elective procedures?
Review graph
10 g/ dl
Balance bw reology ( slowed microvascular flow due to increased viscosity)
AND
Optimal oxygen carrying capacity
T/F re inadequacy of preparation of a diabetic who is admitted for major elective surgery. Thus cannot receive the surgery. 1. Ketonuria 2. BG >9 mmol/ l 3. Glycosuria 4. Metabolic acidosis 5. Proteinuria
- True
- True
- False
- True
- False
Arrange following anesthetic breathing circuits in order of effectivity with re to the minimum FGF that can be used with safety during spontaneous breathing.
Put circuit with safest lowest FGF first
Ventilation?
Circle
Magill (M-A)
Bain (M-D)
Circle
Bain
Magill
Thus nb to understand that
For spontaneous breathing Magill is better.
But for ventilation the T piece is better.
Give the formula for calculating minute volume of ventilation:
Tidal volume x freq of breathing
Tidal volume = Va + Vd
alveolar ventilation , deadspace ventilation
Give the FGF of the following for
- Spontaneous breathing
- Controled ventilation
M - DEF
M-A
Circular
Also what is the MV of adult?
M-DEF
- 2-3 x MV
- 1x MV
M-A
- 0.7 x MV
- 2-3 x MV
Circular: relative unimportant
70ml/kg/ min minute volume for normal person
List groups of pt with increased risk of vomiting/ regurgitation and possible aspiration, during anesthetic induction?
Pregnant GERD Full stomach GIT obstruction, incl ileus Incr intra abd pressure IAP Difficult airway Emergency, pain, opioids Stress Obesity?
List three groups of agents you woud like to admin preoperatively in circumstance of incr aspiration risk with anethetic induction.
PPIs - omeprazole
H2antagonist - ranitidine
Non - particulate antacid - sodium citrate
A derc. In BP is common after administration of spinal anesthetics.
- What is the reason for the decr. in BP?
- When would you institute therapy?
- Briefly explain how you would Rx the hypoT?
1. Spinal causes sympathectomy of spinal roots
Anywhere from T1-L2 - depending on where block is.
Effects:
Vasodilation (venpus and arterial)
Venous pooling and derc. CO
Drop in SVR (arterial vasodilation)
Thus BP = COx SVR
Drop in BP
- MAP
What vasocontrictors can you use to rx low BP with spinal block?
Alpha and Beta agonists
1. Ephedrine : 5-10mg
- Etilephrine : 1-2mg Effortil
Pure alpha agonist: can cause bradycardia
(Baroreceptor response)
- Phenylephrine : 50-100microgram
Ypu are ventilating a pt under GA (has NMB and is paralyzed) Refer to: 1. Mechanism of work 2. Resultant tidal volume 3. Inspiratory pressure
What will happen?
A: Ventilator is a pressure generator type ventilator- how will the ventilator react if there is uncoupling of the pt from the ventilator?
B: ventilator is a volume type - how will it react if there is partial obstruction of the inspiratory limb of the breathing circuit?
What will the tidal volume be if you are using a flow type ventilator. Settings:
Insp time: 1.5 sec
Insp flow: 500ml/sec
A: Ventilator will cont to deliver volume because the preset inspiratory pressure cannot be reached.
B: flow rate will increase to deliver the set tidal volume within the allotted time.
Pressure = flow/resistance thus pressure will
increase
Normal pressure is 20cm H2O and this might drastically be exceeded if the obstruction persists
*** inspiratory time 1.5sec and insp.flow 500ml/sec
This 750ml
Which opioid is best lowers the MAC the most when used with IAA? Review graph
What do you call this rxn?
Morphine
Synergistic rxn
Ketamine as anelgesic:
4 situations
Usefull as supplement to regional anesthetics when pt still experinces intraop pain / discomfort
Provide anelgesia with dressing changes for burn pts.
Very low dose ( 0.05) potentiate epidural anelgesia, also derc tendency to develop chronic pain.
Enhances, sparing effect, reduce sfx of opiods
