PeriOp Flashcards
(242 cards)
2hyp2.1A high mixed venous oxygen saturation (SvO2) is most likely to be associated with
a. COPD
b. PE / Tamponade
c. Acute MI
d. Severe liver failure
e. Sepsis
d. Severe liver failure
but could also be
e. Sepsis
LIFTL:
INTERPRETATION
High SvO2
- increased O2 delivery (increased FiO2, hyperoxia, hyperbaric oxygen)
- decreased O2 demand (hypothermia, anaesthesia, neuromuscular blockade)
- high flow states: sepsis, hyperthyroidism, severe liver disease
Low SvO2
- decreased O2 delivery:
1. decreased Hb (anaemia, haemorrhage, dilution)
2. decreased SaO2 (hypoxaemia)
3. decreased Q (any form of shock, arrhythmia)
- increased O2 demand (hyperthermia, shivering, pain, seizures)
- Causes of High SvO2 despite evidence of End-organ Hypoxia:
1. microvascular shunting (e.g. sepsis)
2. histotoxic hypoxia (e.g. cyanide poisoning)
3. abnormalities in distribution of blood flow
Anesthesia Monitoring Of Mixed Venous Saturation:
https://www.ncbi.nlm.nih.gov/books/NBK539835/
In sepsis, ScvO2 less than 70% or SvO2 lower than 65% correlate with poor prognosis.[2] In application, certain studies have shown that maintaining a goal ScvO2 greater than 70% leads to reduced mortality.[11] Therefore, ScvO2 is used to guide treatment algorithms in the Surviving Sepsis Campaign (SSC).
Studies have shown that normal to higher levels of mixed venous oxygen saturation in patients with clinically worsening sepsis do not rule out tissue hypoxia due to the inability to utilize O2.[11][7] Therefore, several studies support the conclusion that abnormally low or high ScvO2 correlates with higher mortality in patients with septic shock.
A medication that would be acceptable to a patient who refuses all products derived
from human plasma is:
a) Prothrombinex
b) Activated factor 7
c) Fibrinogen concentrate
d) Albumin
e) anti-d
Factor 7 - Recombinant, made from baby hamster kidney cells
Albumin - Alburex® 5 AU (Human Albumin 50 g/L) is an Australian manufactured albumin product
Fib con - Lyophilised precipitate. manufactired from cryoprecipitate.
PCC - Prothrombinex-VF® is a lyophilised concentrate of human coagulation factors containing factors II, IX and X and a small amount of factor VII.
Red cross lifeblood.
Correct answer is rVIIa
Phaeochromocytoma commonly presents with all of the following EXCEPT:
a) RV Hypertrophy
b) Pulmonary HTN
c) long QT
d) ST changes
e) Cardiomyopathy
b) Pulmonary HTN
Long QT + ST changes common
Cardiomyopathy less common but well documented
RVH possible, although more commonly LVH
Organ procurement after circulatory death is generally stood down if the time from
cessation of cardiorespiratory support to circulatory death extends beyond:
a) 60min
b) 90min
c) 120min
90 mins
30mins
Liver
Pancreas
Heart
60mins
Kidneys
90mins
Lungs
Page 35 ANZICS statement 2.4.3 Warm ischemia time
Donate life
The bipolar leads of a 12-lead electrocardiogram are:
a) All
b) V1-V6
c) aVL, aVR, aVF
d) I, II, III
e) None
D) I, II, III
3-electrode system
- Uses 3 electrodes (RA, LA and LL)
- Monitor displays the bipolar leads (I, II and III)
Life in the Fast Lane
The Glasgow Blatchford score is used to risk stratify:
a) Pulmonary haemorrhage
b) Traumatic intraperitoneal haemorrhage
c) PPH
d) SAH
e) UGI bleed
e) UGI bleed
Stratifies upper GI bleeding patients who are “low-risk” and candidates for outpatient management. Use for adult patients being considered for hospital admission due to upper GI bleeding.
Components: haemoglobin, BUN, initial systolic BP, heart rate > 100, melena present, recent syncope, hepatic disease history, cardiac failure present.
Med-Calc
A single intraoperative dose of 8 mg dexamethasone compared to 4 mg results in:
a) No difference in analgesia
b) No difference in PONV
c) No difference in BSL
d) Increased surgical site infection
B is the answer
Check 4th consensus guidelines
Does show better analgesia
PADDI Trial (Monash and ANZCA) 2021
No difference in infection with dex 8 vs placebo
Anaesthesiology Nov 2021, Vol 135, issue 5 - article by Aus anaesthesiologists
A higher dose
- Will cause more hyperglycaemia in DM patients but not clinically/statiscally significant
- Will improve PONV for 72 hours = possibly
- Some studies show this can improve analgesia - ortho, ent cases particularly
8mg dose recommended
Was the question related to addition of dex in block - Korean study compared 4vs8 in 2018
The minimum age in years for in vitro contracture testing for suspected malignant
hyperthermia is
a) 6
b) 8
c) 10
d) 12
10
All current Australian and New Zealand laboratories follow the guidelines of the European Malignant Hyperthermia Group for In Vitro Contracture Testing.
The EMHG guidelines are summarised as follows:
Age and Weight
The minimum weight limit for Australian and New Zealand laboratories is 30 kg and the minimum age for IVCT is 10 years.
(Emhg actually says min age for muscle biopsy is 4 yrs but lab’s should not test children under 10 yrs without relevant control data)
IVCT details
The biopsy should be performed on the quadriceps muscle (eithervastus medialisorvastuslateralis), using local (avoiding local anaesthetic infiltration of muscle tissue), regional, or trigger-free general anaesthetic techniques.
The muscle samples can be dissected in vivo or removed as a block for dissection in the laboratory within 15 minutes.
The time from biopsy to completion of the tests should not exceed 5 hours.
Muscle specimens should measure 20-25 mm in length and at least four tests should be performed each one using a fresh specimen.
The tests should include a static cumulative caffeine test and a dynamic or static halothane test.
The results should be reported as the threshold concentration, which is the lowest concentration of caffeine or halothane that produces a sustained increase of at least 2 mN (0.2 grams) in baseline force from the lowest force reached.
Regarding sex differences in the incidence of connected consciousness (ability to
respond to command during general anaesthesia) in adults after tracheal intubation
as measured by the isolated forearm technique:
a) Higher in females due to lower propofol ml/kg dose
b) Higher in females despite same dose propofol
c) Higher in males due to lower propofol ml/kg dose
d) Higher in males despite same propofol dose
e) No sex difference
B) higher in females despite same dose propofol
BJA Feb 2023
https://www.bjanaesthesia.org/article/S0007-0912(22)00192-1/fulltext
Females (13%, 31/232) responded more often than males (6%, 6/106). In logistic regression, the risk of responsiveness was increased with female sex (odds ratio [ORadjusted]=2.7; 95% confidence interval [CI], 1.1–7.6; P=0.022) and was decreased with continuous anaesthesia before laryngoscopy
*supplementary table shows dosing between female and male responders vs non responders and dosing is the same
A drug which is unlikely to interfere with skin testing is oral:
a) Diphenhydramine
b) Amitriptyline
c) Prednisolone
d) Risperidone
e) Ranitidine
MAYANK Risperidone
Avoid antihistamines and steroids
TCAs known to interfere
Mayo clinic website
See allergy.org.au - risp mentioned in appendix b as a med that may need held
A healthy woman with an uncomplicated pregnancy has an American Society of Anesthesiologists (ASA) Physical Status classification of:
a) 1
b) 2
c) 3
2
Steph Oral naltrexone should be ceased preoperatively for:
a) 24 hours
b) 48 hours
c) 72 hours
d) 96 hours
NAOMI 72 hours
ANZCA Blue Book 2023
Oral naltrexone should be stopped at least 24 hours and ideally 72 hours prior to elective surgery.
And there is a lack of instruction re Contrave- so best to stop 72 hours prior.
And limited evidence re low dose naltrexone for chronic pain - so for consistency blue book says 72 hours.
Caution increased opioid sensitivity in patients using perioperative naltrexone.
Steph In a patient presenting with an Addisonian crisis, the electrolyte disturbances MOST LIKELY to be seen are:
a) Low BSL, hyperkalaemia, hyponatraemia
b) High BSL, hyperkalaemia, hyponatraemia
c) Hypocalcaemia, hyperkalaemia, hyponatraemia
d) Hypercalcaemia, hyperkalaemia, hyponatraemia
a) Low BSL, hyperkaelamia, hypernatraemia
Adrenal crisis is a medical emergency and should be considered in any patient presenting with one or more of the following symptoms:
* altered consciousness
* circulatory collapse
* hypoglycaemia
* hyponatraemia
* hyperkalaemia
* seizures
* history of steroid use/withdrawal
* any clinical features of Addison disease
Adrenal crisis may be precipitated by stress, sepsis, dehydration or trauma; clinical features may be modified accordingly. In patients with known adrenal insufficiency, nonadherence with therapy, inappropriate cortisol dose reduction or lack of stress related cortisol dose adjustment can cause adrenal crisis.
Aus Family Physician - RACGP
Re chat below - incorrect recall, have updated
A
Why A? All three should be seen - glucocorticoid deficiency causes low Na and glucose while simultaneous mineralocorticoid deficiency low K.
Crisis typically presents with hypotension abdo pain, nausea, vomiting and confusion. No one electrolyte/lab value can tie all those together.
A 50-year-old has had a headache for the last month which is relieved by lying flat. They have had no medical procedure to their spine such as epidural, spinal or lumbar puncture. Their brain magnetic resonance (MR) imaging scan shows diffuse
meningeal enhancement and brain sagging. The neurologist suspects spontaneous intracranial hypotension and asks you to do an epidural blood patch. No spinal imaging has been performed to confirm a cerebrospinal fluid (CSF) leak. You should
A do LP to measure pressure if low do lumbar patch
B do blood patch at lumbar level with no further investigation
C do spine imaging if CSF leak present do blood patch at level
D do spine imaging if CSF leak present do lumbar blood patch
E refuse to do blood patch
REPEAT
B do blood patch at lumbar level with no further investigation
A patient presents for a trans-urethral resection of the prostate (TURP). He had a single drug-eluting coronary stent for angina pectoris inserted six months ago and is taking clopidogrel and aspirin. The most appropriate preoperative management of his medications is to:
a) Cease aspirin, continue clopidogrel
b) Cease aspirin for 10 days, cease clopidogrel for 5 days
c) Cease clopidogrel for 5 days, continue aspirin
d) Cease clopidogrel for 10 days, continue aspirin
e) Continue both aspirin and clopidogrel
REPEAT
c) Cease clopidogrel for 5 days, continue aspirin
- prostatic surgery, the risk of major bleeding may be greater than the risk of stent thrombosis
- For clopidogrel, we stop five days before surgery
- Clopidogrel, if stopped, should be restarted with a loading dose of 300 mg as soon as possible after surgery, perhaps later in the day if postoperative bleeding has stopped. Some experts recommend a higher loading dose of 600 mg to decrease time to effectiveness in the higher-risk postoperative setting
- suggest that surgery be performed in centers with 24-hour interventional cardiology coverage
UP TO DATE: Noncardiac surgery after PCI
Nonemergency noncardiac surgery — For patients who have undergone previous stenting with either BMS or DES and who will need cessation of one or both antiplatelet agents, we prefer to defer planned nonemergency, nonurgent noncardiac surgery until at least six months after stent implantation. The risks of noncardiac surgery before six months are increased after both BMS and DES.
For patients whose surgery requires cessation of one or both antiplatelet agents and cannot wait six months, and where the risks of delaying surgery outweigh the benefits, our recommended minimal duration of DAPT is four to six weeks, depending on the urgency of surgery and risk of thrombotic complication. This is based in part on evidence suggesting that the increased risk of MI and cardiac death is highest within the first month after stent placement and no clear difference in risk between BMS and DES. Although we prefer to wait at least six weeks when possible, in patients for whom earlier surgery is in their best interest after weighing risks and benefits, we sometimes refer patients as early as four weeks after stent placement.
The proinflammatory and prothrombotic risks of surgery may increase the baseline risk of stent thrombosis even in the presence of DAPT and regardless of stent type during this early period after stenting. We believe this risk to be higher prior to the minimum duration of DAPT recommended above, but the final decision to continue or discontinue antiplatelet therapy in the perioperative period should be made only after an informed discussion among the surgeon, managing cardiologist (and other health care providers), and patient has taken place. In many cases, DAPT can be continued in the perioperative period, although for some surgeries, such as neurosurgery, posterior eye surgery, or prostatic surgery, the risk of major bleeding may be greater than the risk of stent thrombosis.
In these patients who undergo noncardiac surgery before the recommended minimum duration of DAPT, a platelet P2Y12 receptor blocker should be discontinued for as brief a period as possible. Aspirin should be continued through the perioperative period, since the risk of stent thrombosis is further increased with the cessation of both aspirin and clopidogrel and surgery can usually be safely performed on aspirin. The rationale to continue aspirin comes in part from the POISE-2 trial (PCI subgroup analysis), which is discussed separately. However, as many neurosurgical patients, for whom bleeding might be life threatening or lead to severe adverse outcomes, were not enrolled in POISE-2, the optimal strategy is not known.
●Minor surgical and dental procedures usually do not require cessation of antiplatelet therapy.
●With regard to stopping P2Y12 inhibitor prior to noncardiac surgery, we generally follow recommendations found in the manufacturer’s package insert for each drug.
- For clopidogrel, we stop five days before surgery; that is, the last dose is taken on the sixth day before surgery.
- For prasugrel, we stop seven days before surgery.
- For ticagrelor, we stop three to five days before surgery.
- Some experts are willing to recommend shorter discontinuation periods for procedures less likely to be associated with major bleeding.
●Clopidogrel, if stopped, should be restarted with a loading dose of 300 mg as soon as possible after surgery, perhaps later in the day if postoperative bleeding has stopped. Some experts recommend a higher loading dose of 600 mg to decrease time to effectiveness in the higher-risk postoperative setting.
●We suggest that surgery be performed in centers with 24-hour interventional cardiology coverage
According to the 5th National Audit Project (NAP5), the incidence of awareness during general anaesthesia using a non-relaxant technique with a volatile agent is approximately:
a. 1:700
b. 1:8000
c. 1:10000
d. 1:19000
e. 1:136,000
REPEAT
e. 1:136,000
https://www.bjanaesthesia.org/article/S0007-0912%2817%2930746-8/fulltext
1/670 E-LSCS
1/8000 with muscle relaxation
1/8600 CTS
1/8200 Volatile + neuromuscular blocking
Overall 1:19000
A patient for elective general anaesthesia has been noted to be chewing gum in the pre-operative area. The most appropriate course of action is to:
a) Delay 1 hour
b) Delay 2 hours
c) Delay 6 hours
d) Proceed
e) Cancel
d) Proceed
ANZCA PG07 appendix 1 - Chewing gum and boiled sweets should be discarded prior to inducing anaesthesia to avoid them being Inhaled as a foreign body but do not constitute an indication for delaying any procedure unless they have been ingested.
Therefore D
NP A 74-year-old presents for a femoral popliteal artery bypass procedure for peripheral limb ischaemia. Regarding its role in modifying their perioperative cardiovascular risk, clonidine:
a. Increased stroke
b. No change in complications
c. Increased death
d. Increased non fatal MI
e. Increased risk of non fatal cardiac arrest
REPEAT
e. Increased risk of non fatal cardiac arrest
POISE II
* clonidine 200mcg per day - did not reduce the rate of composite outcome of death or nonfatal MI - but it increased the risk of clinically important hypotension and nonfatal cardiac arrest
* aspirin initiation or continuation – no significant effect on rate of composite of death or non fatal MI but increased risk of major bleeding
Clonidine, as compared with placebo, was associated with an increased rate of nonfatal cardiac arrest
POISE 2 TRIAL
NP A drug that is contraindicated for a patient with a history of heparin induced thrombocytopaenia is:
a) Bivalirudin
b) Danaparoid
c) Prothrombinex
d) Fib conc
B) prothrombinex.
Prothrombinex product information states don’t give if hx of HITS
PROTHROMBINEX CONTAINS HEPARIN
A patient with known suxamethonium allergy is most likely to demonstrate cross reactivity with:
a. Mivacurium
b. Cisatracurium
c. Atracurium
d. Rocuronium
e. Cephazolin
REPEAT
AT - Rocuronium
Anaphylaxis to neuromuscular blocking drugs: incidence and cross-reactivity in Western Australia from 2002 to 2011 by Sadleir et al
(This paper was referenced in NAP 6 “Cross-sensitivity, based on skin testing and specific IgE, is common, with suxamethonium being the most commonly crossreacting drug (Sadleir 2013).”)
Fig 4 shows Rates of cross-reactivity for patients diagnosed with anaphylaxis according to the triggering NMBD.
- for sux anaphylaxis: highest cross-reactivity was roc (24%), then interestingly vec and cis were both tied at 12%, as were panc and atrac at 6%
PREVIOUS NOTES:
BJA Anaphylaxis to neuromuscular blocking drugs: incidence and cross-reactivity in Western Australia from 2002 to 2011
https://academic.oup.com/bja/article/110/6/981/245571
Rocuronium has a higher rate of IgE-mediated anaphylaxis compared with vecuronium, a result that is statistically significant and clinically important.
Cisatracurium had the lowest rate of cross-reactivity in patients who had previously suffered anaphylaxis to rocuronium or vecuronium.
Anaphylaxis rates (highest to lowest)
Primary anaphylaxis: rocuronium > atracurium > vecuronium > pancuronium = cisatracurium
Cross-reactivity: suxamethonium > rocuronium > vecuronium > pancuronium > atracurium > cisatracurium
The correct blood collection tube for a mast cell tryptase test is a:
a. Potassium EDTA
b. serum separating tube
c. sodium citrate
d. sodium oxalate something
REPEAT
b. serum separating tube (gold top tube or red)
Potassium EDTA (purple)
-> FBC
sodium citrate (blue)
-> clotting screen/Rotem
sodium oxalate (green)
-> heavy metals (lead copper zinc)
A new antiemetic reduces the risk of post-operative vomiting by 20%. In a population with a baseline risk of post-operative vomiting of 10%, the number needed to treat is:
a. 2
b. 5
c. 10
d. 20
e. 50
AT
REPEAT
(base rate is 10%, experimental group is 8% (20% below 10%) therefore 100/ 2 = 50
or 1 divided by risk reduction
population risk = 10/100 patients get PONV
population risk + new antiemetic = 8/100 patients get PONV (8/100 as reduction by 20% with new drug)
RR= 0.10-0.08=0.02
NNT= 1/RR
=1/0.02
=50
A risk factor which increases the likelihood of developing local anaesthetic systemic toxicity is:
a) Hypoxia
b) Alkalaemia
c) High alpha1-acid glycoprotein
d) Hypocarbia
e) Increased carnitine levels
AT
REPEAT
b) Hypoxia
Hypoxia
Local anaesthetics are bases with pKa above physiological pH. The more alkalaemic the environment the more unionionised (B) form there is – which will speed diffusion across plasma membrane = can exert Na+ channel blockade.
https://www.bjanaesthesia.org/article/S0007-0912(17)38238-7/pdf
https://academic.oup.com/bjaed/article/15/3/136/279390
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6087022/
Hypoxia – metabolic acidosis = ion trapping = increased toxicity
Alkalaemia = prevents ion trapping in tissues (intralipid can work) = reduced toxicity
High a1GP = reduced free fraction (a1gp high affinity, low capacity) = reduced toxicity
Low CO2 = alkalosis = prevents ion trapping in tissues (intralipid can work) = reduced toxicity
Carnitine deficiency = increased toxicity, therefore increased carnitine will reduce toxicity https://pubmed.ncbi.nlm.nih.gov/19849674/
a. Hypoxia - Yes
b. Alkalemia - No - acidosis causes increased ionised fraction due to its weak base properties
c. High α1-acid glycoprotein - No, normally bound to alpha-1 acid glycoprotein
d. Hypocarbia < (decreased seizure threshold) - No - hypercarbia increases CNS blood flow and increases risk of seizures due to more LA delivered to CNS
e. Increased carnitine levels -s - Never heard of it
The image below shows results from non-inferiority trials. The trial labelled ‘M’ is best described as:
a) Non inferiority graph (line crossed the 0 line but not non-inferior dotted line)
NIKKI