20.2 Flashcards

Question

20.2 Intraoperative cell salvage is contraindicated in

Answer 1

e. VOO >Asynchronous mode most often the result of magnet application. In a ventricular PPM, this means VOO >However, various sources recommend against use of magnet for PPM management due to inconsistent effects on different devices Equipment in Anaesthesia and Critical Care: > The use of a magnet as a solution for pacemaker problems, either in theatre or otherwise is not recommended. >The application of a magnet to the pacemaker can have unpredictable results, from causing it to change to a back-up mode such as VOO, to reverting to factory settings, to performing various self-tests, to switching off entirely.

Answer 2

c. 90 Warm ischaemia time: - Time from treatment withdrawal to the start of cold perfusion of the donated organs - Significance is the impact on graft function - Most important phase of WIT begins when the systolic BP is < 60mmHg - This includes the waiting period from the absence of circulation to the declaration of death and the time before initiating the flow of cold perfusate through the cannula Maximum WARM Ischaemia time - Heart 30 mins - Liver 30 mins - Pancreas 30 mins - Kidney 60 mins - Lungs 90 mins Maximum COLD Ischaemia time: - Heart = 4 hrs - Lungs = 6-8hrs - Liver/Pancreas = 12hrs (DBD)/6 hrs (DCD) - Kidneys = 18hrs (DBD)/ 12 hrs (DCD)

Answer 3

BJA Education Article - Anaesthetic management of patients with a congenital diaphragmatic hernia https://www.bjaed.org/article/S2058-5349(18)30013-1/fulltext

Answer 4

c Laparotomy, Right thoracotomy Ivor-Lewis transthoracic esophagectomy — The Ivor-Lewis transthoracic esophagectomy can be used to resect cancers in the lower third of the esophagus but is not the optimal approach for cancers located in the middle third because of the limited proximal margin that can be achieved. This procedure combines a laparotomy with a right thoracotomy and an intrathoracic esophagogastric anastomosis. This approach permits direct visualization of the thoracic esophagus and allows the surgeon to perform a full thoracic lymphadenectomy. We prefer a minimally invasive Ivor-Lewis approach to a thoracotomy. Transhiatal esophagectomy — A transhiatal esophagectomy (THE) can be performed to resect cervical, thoracic, and esophagogastric junction (EGJ) esophageal cancers; it is performed through an upper midline laparotomy incision and a left neck incision, typically without a thoracotomy. Modified Ivor-Lewis transthoracic esophagectomy (left thoracoabdominal esophagogastrectomy) — A modification of the Ivor-Lewis transthoracic esophagectomy includes a left thoracoabdominal incision with a gastric pull-up and an esophagogastric anastomosis in the left chest. This approach is most useful for tumors involving the gastroesophageal junction. Only one incision is required, but disadvantages include a high incidence of complications such as postoperative reflux and limitation of the proximal esophageal margin by the aortic arch. Tri-incisional esophagectomy — The tri-incisional esophagectomy combines the transhiatal and transthoracic approaches into a transthoracic total esophagectomy with a thoracic lymphadenectomy and cervical esophagogastric anastomosis. The three-incisional technique allows the surgeon to perform a complete two-field (mediastinal and upper abdominal) lymphadenectomy under direct vision and a cervical esophagogastric anastomosis. We prefer a thorascopic approach to the chest rather than a thoracotomy to minimize the risk of respiratory complications. Esophagectomy is a technically difficult operation, and the complication rate is high due to the anatomic challenges of the procedure. The choice of surgical approach depends upon many factors, including: ●Tumor location, length, submucosal extension, and adherence to surrounding structures ●The type or extent of lymphadenectomy desired ●The conduit to be used to restore gastrointestinal continuity ●Postoperative bile reflux ●The preference of the surgeon

Answer 5

d 60cm H2O

Answer 6

Arndt bronchial blocker - use with SLT - 9fr, loop around scope for positioning - suction to deflate lung

Answer 7

b. 30 mcg/L

Answer 8

a) Pulmonary embolism A bit about the RV in PE: The right ventricle drapes around the LV. In response to an acute Pulmonary Embolus (PE) it first dilates. The RV can’t generate much force without training, so when the Pulmonary Vascular Resistance (PVR) first rises with a PE, the pulmonary artery pressures don’t actually rise substantially because the RV can’t generate large pressures. Looking at the ventricle in short axis, the septum may bow towards the LV which will form a D shape in diastole, producing a “volume overloaded right ventricle” appearance. Only later when the RV has been trained will it be able to generate higher pressures. If the LV is D shaped in systole, this is a “pressure overloaded right ventricle”. Acute cor pulmonale with both pressure AND volume overload (D shape in systole AND diastole) is often absent.

Answer 9

Answer: 3%. Principle: If Vaporizer specific for agent with low SVP (Enflurane or Sevoflurane) is misplaced with an agent that has high SVP (halothane or isoflurane) then actual output concentration will be greater than the concentration indicated by dial. (inverse is also true) Administration of sevoflurane using other agent-specific vaporizers: The current study investigated the concentration of sevoflurane that could be achieved when sevoflurane was administered using standard agent-specific halothane, isoflurane, and enflurane vaporizers. An artificial lung analog model was made by attaching the 3-L reservoir bag to the 15-mm end of the anesthesia circle system. The lung analog was attached and ventilated with oxygen and air at flow rates of 2 L/min each (total gas flow = 4 L/min), a tidal volume of 800 mL, a rate of 10 breaths/min, and an inspiratory-to-expiratory ratio of 1:2. The vaporizer was filled with sevoflurane and the dial turned to 1%. After a 10-minute equilibration period, the concentration of sevoflurane was measured. The vaporizer concentration was increased in 1% increments, and after a 10-minute equilibration, the sevoflurane concentration was recorded. The dial was increased from 1% to 5% for the halothane and isoflurane vaporizer and from 1% to 7% for the enflurane vaporizer. Each study was repeated five times at each incremental increase of 1% for each of the three vaporizers. The series of studies were repeated using a total gas flow of 8 L/min (oxygen 4 and air 4) instead of 4 L/min (oxygen 2 and air 2). Using the halothane or isoflurane vaporizers at the 5% setting, the maximum sevoflurane concentrations achieved were 3.0% and 3.1%, respectively. The sevoflurane concentration was a maximum of 6% using the enflurane vaporizer set at 7%. The sevoflurane concentration decreased significantly when using any of the three vaporizers at all concentrations when the gas flow was increased from 4 to 8 L/min. The current study demonstrates that clinically useful concentrations of sevoflurane can be achieved with the administration of sevoflurane through an enflurane vaporizer. Although this is not routinely recommended, in specific circumstances it may allow the use of sevoflurane in third-world countries if sevoflurane vaporizers are not available and the use of sevoflurane is clinically necessary.

Answer 10

a) Autonomy - Obligation to respect the decision-making capacities of persons. Non-maleficence: Obligation to avoid causing harm - If refused to proceed. Paternalism: A set of attitudes and practices in which the health provider determines that a patient's wishes or choices should not be honored. - If transfused patient against their wishes Beneficence: Obligation to provide benefits and to balance benefits against risks; obligation of physician to act for the benefit of the patient - Controversial interpretation in this case. Both proceeding and refusing to do case may be acting for the benefit of the patient, depending on how you look at the scenario. BJA: ‘MORAL balance’ decision-making in critical care https://www.bjaed.org/article/S2058-5349(18)30145-8/fulltext

Answer 11

b) Posterior tibial + superficial peroneal

Answer 12

d) Suprascapular Suprascapula nerve (C5,6) - innervates supra and infraspinatus - comes off superior trunk of the brachial plexus, and is usually anaesthetised by an interscalene block - sensory innervation to 70% posterior-superior shoulders and portion of the anterior axilla and the ACJ Supraclavicular nerve (C3,4) - provides sensory to the 'cape' of the shoulder - component of the cervical plexus block - lies outside the brachial plexus - commonly missed during supraclavicular brachial plexus blocks Subscapular nerve: - subscapularis - medial rotation shoulder Dorsal scapular nerve: - branch of the brachial plexus - supplies rhomboid major muscle, rhomboid minor muscle, and levator scapulae muscle - causes the scapula to be moved medially towards the vertebral column - Dorsal scapular nerve syndrome can cause a winged scapula, with pain and limited motion Thoracodorsal nerve: - thoracodorsal nerve also branches from the posterior division of the brachial plexus - this nerve innervates the latissimus dorsi muscle.

Answer 13

c) Pharyngeal muscles BJA: monitoring neuromuscular blockade - onset and offset of block is faster in central muscles with good blood supply e.g. diaphragm and larynx - peripheral muscles with relatively poor blood supply will have slower onset and a longer recovery time e.g. adductor pollicis - muscles of the upper airway and pharynx behave as central muscles at onset however they are sensitive to NMBD and recovery is slow, mirroring peripheral muscles Induction of anaesthesia: > Orbicularis oculi ideal muscle to monitor at this time as it is more similar to a central muscle: onset is similar to diaphragm and larynx > single twitch or TOF is the most valuable stimulation pattern Maintenance anaesthesia > as diaphragm is relatively resistant, a more sensitive peripheral muscle such as adductor pollicis may not adequately reflect the degree of block required, a central muscle such as orbicularis oculi will reflect the diaphragm more closely Reversal and recovery: > a peripheral muscle such as adductor pollicis is the best option as resp muscles are likely to haverecovered to a greater degree, and peripheral monitoring provides a larger margin of safety

Answer 14

c) Increased mortality Use of perioperative metoprolol was associated with: * Decreased rate of myocardial infarction * Decreased rate of revascularisation * Decreased rate of developing new atrial fibrillation * INCREASED rate of death * INCREASED rate of stroke * INCREASED rate of significant hypotension INCREASED rate of significant bradycardia

Answer 15

e Plasma esterases Plasma esterases (not cholinesterase) Esmolol metabolism is via RBC esterases.

Answer 16

c) Medial cord

Answer 17

b) Lateral cord

Answer 18

a) Posterior Cord

Answer 19

d) ECG ECG – have AVAILABLE for every anaesthetised patient. Should be used for patients undergoing general and major regional anaesthesia AS CLINICALLY INDICATED. Oxygen analyser – continuous operation for every patient when anaesthesia breathing system in use. Pulse oximeter – use for every patient undergoing general anaesthesia or sedation. Carbon dioxide monitor – use for every patient undergoing general anaesthesia, and have immediately available for sedation cases. ET Volatile – should be in use for every patient undergoing general anaesthesia from an anaesthesia delivery system where inhalational anaesthetic agents are delivered.

Answer 20

Warfarin – no effect on thrombin time Heparin - causes considerable prolongation of TT. LMWH, fondaparinux or direct factor Xa inhibitors have no effect on TT as the predominantly inhibit factor Xa. However LMWH in very high concentration can affect TT. Dabigatran, Bivalirudin and other direct thrombin inhibitors prolong TT considerably. The thrombin time (TT), also known as the thrombin clotting time (TCT) is a blood test that measures the time it takes for a clot to form in the plasma of a blood sample containing anticoagulant, after an excess of thrombin has been added. Warfarin prevents thrombin synthesis but does not inhibit it, therefore no effect on TT.

Answer 21

c) Lower airway obstruction Peripheral or lower airways obstruction: expiratory limb demonstrates concave upward, also called "scooped-out" or "coved" pattern.

Answer 22

d) Fixed upper Airway obstruction Fixed upper airway obstruction (can be intrathoracic or extrathoracic): flow limitation and flattening are noted in both the inspiratory and expiratory limbs of the flow-volume loop.

Answer 23

a) Variable intra-thoracic obstruction Dynamic (or variable, nonfixed) intrathoracic obstruction: flow limitation and flattening are noted on the expiratory limb of the loop.

Answer 24

e) Normal Normal flow-volume loop: the expiratory portion of the flow-volume curve is characterized by a rapid rise to the peak flow rate, followed by a nearly linear fall in flow. The inspiratory curve is a relatively symmetrical, saddle-shaped curve.

Answer 25

Repeat d) Sarcoidosis Normal FEV1/FVC ratio = no obstruction Low FVC = restrictive pattern Low DLCO = interstitial lung disease Asthma and emphysema would have obstructive pattern. Myasthenia gravis would have normal DLCO Pulmonary HTN would have normal spirometry and low DLCO.

Answer 26

d) Encephalitis Complications of dural puncture include: 1. PDPH 2. hearing loss 3. pneumocephalus (if LOR to air) 4. chronic headache 5. chronic back pain 6. subdural haematoma 7. cerebral vein thrombosis 8. bacterial meningitis 9. diplopia 10. cranial nerve palsy 11. seizures

Answer 27

e) Left lingula LEFT LUNG: ASIA ALPS Apical Posterior Superior lingula Inferior lingula Anterior Anterior basal Lateral basal Posterior basal Superior RIGHT LUNG: A PALM Seed Makes Another little Palm RUL: Apical Posterior Anterior RML: Lateral Medial RLL Superior Medial basal Anterior basal Lateral basal Posterior basal

Answer 28

Vastus Medialis

Answer 29

Adductor Magnus

Answer 30

e) Maintain SBP 140-180 1. Tight control of BP, preferentially with IABP > goal of >140/90 mmHg and <180/105 mmHg. 2. Oxygen supplementation to maintain SpO2 >92%. 3. Maintenance of eucapnia to avoid cerebral vasoconstriction > (ETCO2 35- 45 mmHg) 4. Temperature maintained 35-37c 5. Euglycaemia (BGL 70-140 mg/dL (4-8 mmol/L)) and hourly monitoring

Answer 31

Chemosis is NOT a sign of arterial retrobulbar haemorrhage Signs of arterial retrobulbar haemorrhage: 1. Sudden onset proptosis 2. Raised IOP 3. Reduced acuity.

Answer 32

c) 1000 ml/hr 4ml/kg/hr x 30%TBSA x 100kg = 12,000mL 1/2 within the first 8hrs, remainder over the next 16 hours (starting at 6 hour mark in this stem so beware) 6,000mL/6hrs = 1000 mL/hr which is the rate you would run it over the next 6 hours.

Answer 33

b) Propofol BJA: No evidence for contraindications to the use of propofol in adults allergic to egg, soy or peanut "No connection between allergy to propofol and allergy to egg, soy or peanut was found. The present practice of choosing alternatives to propofol in patients with this kind of food allergy is not evidence based and should be reconsidered."

Answer 34

c) Dabigatran Idarucizumab (Praxbind) is a monoclonal antibody to dabigatran Dabigatran bleeding may be treated with: - idarucizumab - haemodialysis - TXA will decrease fibrinolysis and has some effect - FFP also has some effect Humanized monoclonal antibody fragment (Fab) indicated in patients treated with dabigatran (Pradaxa) when reversal of the anticoagulant effects are needed for emergency surgery or urgent procedures, or in the event of life-threatening or uncontrolled bleeding - 5 g IV, provided as 2 separate vials each containing 2.5 g/50 mL (see Administration) - Limited data support administration of an additional 5 g Dosage Modifications Renal impairment: Renal impairment did not impact the reversal effect of idarucizumab; no dosage adjustment required Hepatic impairment: Not studied Dosing Considerations This indication is approved under accelerated approval based on a reduction in unbound dabigatran and normalization of coagulation parameters in healthy volunteers; continued approval for this indication may be contingent upon the results of an ongoing cohort case series study

Answer 35

Nitrous oxide Halothane & isoflurane cause catalytic destruction of ozone, but halothane hardly used and isoflurane has short atmospheric lifetime. Desflurane + sevoflurane don’t cause ozone depletion.

Answer 36

Answer: a) Codeine TGA Pregnancy categories https://www.tga.gov.au/prescribing-medicines-pregnancy-database Category A ■ Codeine Category C ■ Methadone ■ Tramadol ■ Oxycodone ■ Morphine

Answer 37

C. Opioids A. Non-depolarising muscle relaxants - false - NMBDs abolish MEPs B. Nitrous oxide - false - N2O can completely abolish MEPs D. Propofol - false - PPF has less of an effect than volatiles, but still affects MEPs E. Volatiles - false - volatiles are the most likely NMBDs > volatiles > N2O > PPF > opioids https://www.uptodate.com/contents/anesthesia-for-elective-spine-surgery-in-adults While neurologic injury can cause changes in recorded potentials, other factors can interfere with interpretation. Confounding factors that can occur during surgery include inhalational anesthetics, hypothermia, hypotension, hypoxia, anemia, and preexisting neurologic lesions. Inhaled anesthetics such as isoflurane, sevoflurane, and nitrous oxide can reduce the amplitude and prolong the latency of SSEP and can completely abolish MEP. Neuromuscular blocking agents (NMBAs) also abolish motor evoked potentials and cannot be used when monitoring. Intravenous anesthetics such as propofol, barbiturates, and opioids have less of an effect on monitoring, though very deep anesthesia, even with propofol, can affect waveforms. https://www.uptodate.com/contents/neuromonitoring-in-surgery-and-anesthesia Evoked potentials — Evoked potential monitoring is used to assess the integrity of the tested neural pathway. Somatosensory, visual, and brainstem auditory evoked potentials monitor neurologic structures between peripheral sites where specific stimulations are applied, and responses are recorded from central locations. Motor evoked potentials monitor such structures by stimulating the motor cortex and recording from the epidural space (D-wave) or, more commonly, from distal muscles. Changes in evoked responses can result from technical, positional, pharmacologic, physiologic, or surgical causes. For spine surgery, both MEPs and SSEPs are used to monitor spinal cord function to increase sensitivity. Motor and sensory tracts are anatomically distinct and have different vascular supply in areas of the cortex, brainstem, and spinal cord. Motor evoked potentials (MEPs) – MEP responses are affected by even very low concentrations of volatile anesthetic agents. In general, total intravenous anesthesia (TIVA) facilitates MEP monitoring. However, inhalation agents at 0.5 MAC or less can be used in many patients, especially during intracranial surgery Opioids – IV opioids cause small, dose-dependent depression of SSEP and MEP responses, though even at very high doses of opioids, evoked potentials can be recorded [76-78]. Infusions of remifentanil, fentanyl, or sufentanil are commonly used as part of TIVA during neuromonitoring. Opioids tend to produce high-amplitude slow waves in the EEG. Balanced anesthetic approach — When SSEPs and MEPs are monitored, a balanced anesthetic using both a low-dose inhalation anesthetic (up to 0.5-MAC isoflurane, sevoflurane, or desflurane) and low- to medium-dose propofol (eg, propofol, 40 to 75 mcg/kg/min IV) with a relatively high-dose opioid (eg, remifentanil 0.1 to 0.4 mcg/kg/min) offers several advantages: ●Movement with motor stimulation is reduced, which is particularly important during intracranial aneurysm surgery. ●The addition of a 0.3 to 0.5 MAC inhalation agent may reduce the chance of awareness under anesthesia. ●Compared with TIVA, the addition of a 0.5 MAC inhalation agent allows reduction of the dose of propofol infusion, facilitating more rapid wakeup and earlier neurologic examination. ●Compared with TIVA, the chance of accidental interruption of the anesthetic for mechanical reasons (ie, kinked or infiltrated IV catheter or tubing such that IV agents no longer infuse) is reduced.

Answer 38

a) Lean body weight FROM SOBA: LBW exceeds IBW in obese and plateaus at ~100kg in men and ~70kg in females IBW used to calculate the adjusted body weight for maintenance infusion of propofol (IBW +40%). IBW calculated using Broca formula (Ht in cm - 100; Ht in cm =105; as optimal weights for men and women respectively in kg)

Answer 39

A. Not offering an epidural on a patient who is labouring spontaneously with a normal pregnancy and no comorbidities, upon request

Answer 40

Answer: a) Bernoulli equation using tricuspid peak + RAP i.e. RVSP = 4v2 + RAP (~PAP in absence of RVOTO)

Answer 41

c) 420 ms i.e. RR interval = 60 / HR; therefore RR interval is 60/60 = 1 420 / square root of 1 is 420ms From LITFL: The corrected QT interval (QTc) estimates the QT interval at a standard heart rate of 60 bpm QT: Time from the start of the Q wave to the end of the T wave Represents time taken for ventricular depolarisation and repolarisation, effectively the period of ventricular systole from ventricular isovolumetric contraction to isovolumetric relaxation The QT interval is inversely proportional to heart rate: The QT interval shortens at faster heart rates The QT interval lengthens at slower heart rates An abnormally prolonged QT is associated with an increased risk of ventricular arrhythmias, especially Torsades de Pointes Corrected QT interval (QTc) The corrected QT interval (QTc) estimates the QT interval at a standard heart rate of 60 bpm This allows comparison of QT values over time at different heart rates and improves detection of patients at increased risk of arrhythmias Bazett formula: QTC = QT / √ RR Note: The RR interval is given in seconds (RR interval = 60 / heart rate).

Answer 42

e Na 140 Mg 1.5 K 5.0 acetate 27 lactate 0

Answer 43

Answer: Hypocalcaemia ● AMH ○ Increased risk of adverse effects related to volume depletion(e.g. hypotension, fainting) ○ UTI

Answer 44

a) Greater auricular

Answer 45

repeat c. 7

Answer 46

Repeat c) Breast milk 3 hours, clear fluids 1 hour to max 3ml/kg Infants <6 months having elective procedure * 4 hours for formula * 3 hours for breast milk * 1 hour for clear fluids (≤3 ml/kg/hr) Children > 6 months having elective procedure * 6 hours for limited solid food or formula * 4 hours for breast milk * 1 hour for clear fluids (≤ 3ml/kg/hr)

Answer 47

Amitriptyline By order of favourable NNT: 1. TCAs (amitriptyline) NNT: 3.6, NNH: 9 2. Strong opioids NNT 4.3 NNH 11.7 3. Tramadol NNT: 4.7, NNH 12.6 4. SNRIs (duloxetine and venlafaxine) NNT 6.4, NNH 11.8 5. Gabapentin NNT: 7.2 NNH 25.6 6. Pregabalin NNT:7.7, NNH 13.9 By order of favourable NNH: 1. Gabapentin NNT: 7.2 NNH 25.6 2. Pregabalin NNT:7.7, NNH 13.9 3. Tramadol NNT: 4.7, NNH 12.6 4. SNRIs (duloxetine and venlafaxine) NNT 6.4, NNH 11.8 5. Strong opioids NNT 4.3 NNH 11.7 6. TCAs (amitriptyline) NNT: 3.6, NNH: 9 ANZCA Pain book Treatment of chronic neuropathic pain after SCI (Guy 2016 GL). These guidelines recommend: * First line: pregabalin, gabapentin and amitriptyline; * Second line: tramadol and lamotrigine (in incomplete SCI); * Third line: Transcranial direct current stimulation (tDCS) alone and combined with visual illusion; * Fourth line: TENS, oxycodone and dorsal root entry zone lesions.

Answer 48

Repeat E. Pulmonary Stenosis

Answer 49

a) Ischaemic optic neuropathy Postoperative visual loss (POVL) occurs in 1/60 000–1/125 000 operations. Spinal surgery has the highest incidence of POVL. American Society of Anesthesiologists (ASA) Post Operative Visual Loss Registry, spinal surgery accounted for 93/131 (70%) of all cases of visual loss after non-ophthalmic surgery. Of these: > 83 were attributable to ischaemic optic atrophy (ION) > 10 were caused by central retinal artery occlusion (CRAO). CRAO - caused by direct pressure on the globe causing raised intraocular pressure and compromising retinal perfusion. - visual loss is usually unilateral and associated with other signs of pressure (e.g. ophthalmoplegia, ptosis, or altered sensation in the territory of the supraorbital nerve). - Initial careful positioning of the head and regular checks throughout the procedure in case of movement minimizes the risk - documentation of eye checks should occur every 30mins and horseshoe shaped head rests should be avoided in prone patients ION > associated with: - male gender - obesity - increasing blood loss - operative procedures >6 hrs in length. - The use of the Wilson frame has also been implicated. > final common pathway is thought to be hypoperfusion of the optic nerve, there is no clear association with either intraoperative systemic hypotension or with the presence of peripheral vascular disease or diabetes. > recently updated ASA practice advisory for POVL associated with spinal surgery recommends regular intraoperative testing of haemoglobin concentration. However, it was unable to suggest a transfusion threshold that would prevent POVL. Other possible causes of POVL: 1. Cortical ischaemia 2. Haemorrhage into a cerebral tumour. In high-risk cases, assessment of vision should be performed as soon as possible in PACU and an early ophthalmic opinion sought if there is a suggestion of visual compromise. Initial management 1. optimization of arterial pressure 2. oxygenation 3. correction of anaemia. Treatment with agents such as acetazolamide has not been beneficial and there is rarely any useful improvement in vision with either injury, so attention should be focused on preventative measures: 1. Careful positioning with the head at the same level as the heart 2. Meticulous haemostasis, 3. Possibly staging prolonged procedures should be considered. Because of the devastating nature of this complication, patients should be informed of an increased incidence of visual loss after spinal operations that are expected to be of prolonged duration and associated with significant blood loss.

Answer 50

b. Unstable angina Not a Repeat, no Tropnin rise in this question making the answer unstable angina as opposed to NSTEMI UTD: Unstable angina (UA) and acute non-ST elevation myocardial infarction (NSTEMI) differ primarily in whether the ischemia is severe enough to cause sufficient myocardial damage to release detectable quantities of a marker of myocardial injury (troponins): ●UA is considered to be present in patients with ischemic symptoms suggestive of an ACS and no elevation in troponins, with or without electrocardiogram changes indicative of ischemia (eg, ST segment depression or transient elevation or new T wave inversion). ●NSTEMI is considered to be present in patients having the same manifestations as those in UA, but in whom an elevation in troponins is present. MINS: Myocardial injury after non-cardiac surgery (up to 30 days post-op): 1. Elevated postop troponin 2. Resulting from myocardial ischaemia (i.e. no evidence of a non-ischaemic aetiology), not requiring an ischaemic feature (i.e. no chest pain, no ECG change) VISION studies (Vascular Events in Noncardiac Surgery Patients Cohort Evaluation) demonstrated that severity of MINS strongly associated with 30-day mortality after NCS. hs-cTnT <20ng/L ~ 0.5% 30 day mortality 20-64ng/L ~3% 30 day mortality 65-999 ng/L ~9% 30 day mortality >1000ng/L ~30% 30 day mortality Whilst VISION trial identified MINS in at risk patients, the question now becomes what interventions are available to prevent this complication?

Answer 51

c) LAD LIFL: Myocardial Ischaemia https://litfl.com/myocardial-ischaemia-ecg-library/ More Myocardial Ischaemia ECG Examples: Example 1 Subendocardial ischaemia: The most striking abnormality is the widespread ST depression, seen in leads I, II and V5-6. This is consistent with widespread subendocardial ischaemia. There is also some subtle ST elevation in V1-2 and aVR with small Q waves in V1-2, suggesting that the cause of the widespread ischaemia is a proximal LAD occlusion.

Answer 52

a. Bullying Bullying is unreasonable behaviour that creates a risk to health and safety. It is behaviour that is repeated over time or occurs as part of a pattern of behaviour. “Unreasonable behaviour” is behaviour that a reasonable person, having regard to all the circumstances, would expect to victimise, humiliate, undermine or threaten the person to whom the behaviour is directed. 1. Direct bullying – behaviour that is overt and usually involves conduct directed at a person to belittle or demean them. Examples include: > Aggressive and intimidating behaviour. > Belittling, degrading or humiliating comments. > Spreading misinformation or malicious rumours. > Interfering with a person’s property or work equipment. > Displaying offensive material (for example pornography). 2. Indirect bullying – behaviour that excludes or removes benefits from a person. Examples include: > Assigning meaningless tasks unrelated to the job. > Setting tasks that are unreasonably below or beyond a person’s skill level. > Deliberately changing work rosters to inconvenience particular employees. > Deliberately withholding information that is vital for effective work performance. Harassment is any type of unwanted behaviour that offends, humiliates or intimidates a person, and targets them on the basis of a characteristic covered by anti-discrimination law, for example gender, race, ethnicity or disability, etc. In general, harassment is any behaviour that is: Unwelcome, not asked for and not returned. Likely to humiliate (put someone down), seriously embarrass, offend or intimidate (threaten or scare) someone. Based on a personal characteristic (or family or friend’s characteristic) protected by law. Discrimination means treating a person with an identified attribute or personal characteristic as set out in legislation less favourably than a person who does not have the attribute or personal characteristic. > Gender. > Transgender, gender history and trans-sexual status. > Pregnancy and potential pregnancy. > Childbirth or breastfeeding. > Marital status. > Sexual orientation. > Lawful sexual activity. > Disability or impairment. > Race (including colour, nationality, descent and origin). > Physical features. > Age. > Carer status and family responsibilities. > Religious belief or activity. > Political belief or activity. > Trade union membership and industrial activity. > Associated with a person who is identified by reference to any of these attributes Sexual Harassment Sexual harassment is against the law. Sexual harassment is unwelcome sexual behaviour, which could be expected to make a person feel offended, humiliated or intimidated. It can be physical, verbal or written. Victimisation Victimisation is unlawful. Victimisation occurs when a person is treated unfairly due to that person having made a complaint of sexual harassment. Victimisation is behaviour that makes a person suffer a detriment including feeling uncomfortable, isolated, insecure or intimidated. https://www.anzca.edu.au/resources/corporate-documents/anzca-policy-on-bullying-discrimination-and-harass.pdf

Answer 53

Repeat a. A+ Group A Plasma component preference 1st choice: A 2nd Choice: AB 3rd Choice: B [a] If the patient is a female of childbearing potential, O RhD negative red cells should be used until the patient’s blood group is established. [b] Group A platelets with the A2 subgroup don’t express significant amounts of A antigen and are therefore preferable to other group A platelets when transfusing group O and B recipients. [c] Apheresis platelets that have a low titre anti-A/B or pooled platelets pose a lower risk of haemolysis when transfusing ABO incompatible components. [d] Plasma components that have low titre anti-A/B pose a lower risk of haemolysis when transfusing ABO incompatible components. [e] Group A plasma may be used as per local institutional policies. 

Answer 54

b) Pulmonary odema B-lines >Vertical echogenic short path reverberation artefacts originating at the pleural line and extending to the deepest part of the ultrasound image. >They interrupt any horizontal A-lines. >Occasional B-lines are considered normal. >More than 3 B-lines in any single view is considered pathological. >Where there are numerous B-lines in close proximity they become confluent. >B-lines move with lung movement. >They are caused by ultrasound energy reverberating in a fluid filled focus that is surrounded by air. These foci may be interstitial or alveolar. >Cardiogenic and noncardiogenic oedema may have very similar appearances. >Interstitial thickening due to fibrosis or lymphangitis can also create the sonographic appearance of diffuse B-lines.

Answer 55

a) Normal lungs Probe selection Linear probe (8–12 MHz) These high-frequency probes give good resolution of superficial structures. As the anterior pleura is relatively superficial, excellent images of the pleura and lung sliding can be obtained. The poor penetration of high-frequency US and the narrow sector width mean deeper structures are poorly imaged. Curvilinear probe (3–5 MHz) This is the best all-round probe for LU. Lung sliding can be easily visualized as can IS. Effusions, consolidated lung, and the diaphragm are also well imaged because of the good penetration and large sector width. The large footprint of the probe means some angulation is needed to avoid the ribs when scanning postero-laterally. Phased array (3–4.5 MHz) These probes have a useful footprint for getting in between the ribs. They can be used to demonstrate all the signs of LU but the clarity of the images is not as good. General points The clearest images are obtained by having the image as shallow as possible with the focus point at the level of interest. The frequency can be adjusted to enhance the image, depending on the depth. Increasing the frequency on a curvilinear probe will improve the appearance of lung sliding whilst worsening the appearance of a consolidated lung base.

Answer 56

a) Normal lungs M-mode image demonstrating seashore sign seen with normal lung sliding.

Answer 57

e) Pneumonia Signs of Pneumonia on lung ultrasound: > Early Pneumonia - B-lines and areas of sub pleural consolidation - Fluid filled alveoli surrounded by air-filled lungs cause a short path reverberation anbd B-lines can be seen - loalised patches of numerous nB-lines indicate sub-pleural consolidation > Hepatization: solid appearing consolidated lung - inflammatoy and ppurulent fluid filled alveoli makes the lung appear solid, with homogenous relatively fine echotexture similar to liver - Atelectasis can also cause solid non-aerated lung and it can be difficult to distinguish the two conditions > Shred sign: irregular consolidation/ air interface - consolidated areas adjacent to aerated areas where the consolidated areas will be linear and well defined > Air bronchograms and dnamic air bronchograms - Air within consolidated area may remain in small aeratedpatches of lung or more commonly air remains within small bronchi, small airbubbles all lined up within a bronchus are known as sonographic air bronchograms - when air bubbles are seen to bubble in and out with each breath the term "dynamic air bronchogram" is used > Colour doppler interrogation: flow remains - pulmonary arterial and venous vasculature are well demonstrated in areas of consolidation Associated pleural effusion or empyema - small hyperechoic parapneumonic effusion are frequently demonstrated - echogenic debris within the effusion suggest empyema

Answer 58

Repeat b. GA Grade 1: moderate hypoxia (Spo2<94%) or hypotension [fall in systolic blood pressure (SBP) >20%]. Grade 2: severe hypoxia (Spo2<88%) or hypotension (fall in SBP >40%) or unexpected loss of consciousness. Grade 3: cardiovascular collapse requiring CPR. Patient Risk factors: 1. old age 2. poor pre-existing physical reserve 3. impaired cardiopulmonary function -> NYHA 3 or 4 4. pre-existing pulmonary htn 5. Male Sex 6. Diuretics 7. ASA grade 3 or 4 8. osteoporosis 9. bony metastases 10. concomitant hip fractures (particularly pathological and intertrochanteric) (latter due to abnormal vascular channels through which marrow contents can enter the circulation) Surgical Risk factors 1. patients with previously un-instrumented femoral canal > revision surgery 2. Use of long-stem femoral component Anaesthetic Risk reduction: - discussion between surgeons and anaesthetists over uncemented vs. cemented based on patient Hx particularly if lon-stem prosthesis, femoral fracture or patients with cardiorespiratory disease - no clear evidence regarding the impact of anaesthetic technique - increase inspired O2 considered in all patients at time of cementation - avoid intravascular volume depletion - Higher level of haemodynamic monitoring in high risk patients Factors NOT predictive of severe BCIS include: Arteriosclerosis Angina pectoris Congestive heart failure Beta-blockers Angiotensin-converting enzyme inhibitors.

Answer 59

b) 4% albumin - SAFE study (2004) showed increased mortality at 24 months when albumin used as resuscitation fluid cf normal saline. - Also caused higher ICP at 1 week post injury. - 4% albumin (274 mOsm/L & 266 mOsm/kg) is hypotonic and hypoosmolar.

Answer 60

c) 1:8000 Awareness rates GA with no muscle relaxant = 1:136,000 GA with muscle relaxation = 1/8,000 CTS 1/8,600 E-LSCS = 1/670 Overall 1:19,000

Answer 61

Decreased SVR Hyperthyroidism: increases HR increases cardiac contractility. increases LVEF increases diastolic relaxation increases CO SVR decreases >T3 induces systemic vasodilation.

Answer 62

B. Initially decreases then normalises Oral glucose tolerance test — The most specific dynamic test for establishing the diagnosis of acromegaly is an OGTT. When performing the test, we measure serum GH before and two hours after glucose administration; the criterion for the diagnosis of acromegaly is a GH concentration greater than 1 ng/mL. In normal subjects, serum GH concentrations fall to 1 ng/mL or less within two hours after ingestion of 75 g glucose. In contrast, the post-glucose values are greater than 2 ng/mL in over 85 percent of patients with acromegaly. Following oral glucose administration in humans, a transient suppression of plasma GH levels for 2–3 h is observed followed by a delayed rise occurring at 3–5 h post glucose ingestion. This initial suppression seems to be related to a glucose-mediated increase in hypothalamic somatostatin release. Evidence supporting this hypothesis emerges from the findings that in healthy individuals, GH secretion in response to GHRH or GH secretagogue is diminished after an oral glucose loa]. Furthermore, the inhibitory effect of glucose is reversed with the acetylcholinesterase inhibitor pyridostigmine, a substance thought to suppress somatostatin release from the hypothalamus. These findings support the hypothesis that oral glucose load is associated with a somatostatin release into the hypophyseal portal blood suppressing GH levels. The delayed GH rise would result from a decrease in somatostatinergic tone and hence an increase in GHRH. Subsequently, the available pituitary stores of GH are released leading to a rebound rise in GH.

Answer 63

Raised ICP *also associated with a difficult airway (Difficult BMV Ventilation) Apert syndrome: Autosomal dominant abnormality of first branchial arch causing premature closure of cranial sutures, midface hypoplasia, choanal atresia, cleft palate, fusion of cervical spine (mainly C5-C6) and syndactyly. May have associated cardiac and renal abnormalities as well as intellectual impairment due to megalocephaly, hypoplasia of white matter and agenesis of the corpus callosum. Obstructive sleep apnea is present in 50% and there may be an increased incidence of upper airway obstruction at induction, which is mostly overcome by routine maneuvers. Classically, craniosynostosis release with fronto-orbital advancement is completed at 6 to 12 months of age if intracranial pressure (ICP) is normal [24-26]. However, elevated ICP may occur in up to 43 percent of cases. In this event, prompt surgical advancement and potentially ventriculoperitoneal shunt placement is required

Answer 64

a. Teicoplanin

Answer 65

c) Discharge from recovery This score assesses five parameters: 1. level of activity 2. respiration 3. circulation 4. consciousness 5. Oxygen saturation Each parameter is scored 0, 1, or 2, and patients scoring 9 or greater are eligible to be transferred from the high-dependency PACU to the ASU. Limitations: > It does not provide an assessment for home-readiness > Does not address some of the common side effects seen in the PACU, such as: - pain - nausea and vomiting - bleeding at the incision site.

Answer 66

Repeat a) Midazolam Blue Book 2019 RLS Definition -Common neurological sensorimotor disorder characterised by the urge to move ones legs -It is associated with unpleasnat paraesthesias deep within the legs during periods of rest or inactivity, whihc are relieved by movement Pathophysiology > RLS can be primary (idiopathic) or secondary > patients with secondary RLS develop symptoms secondary to another disease process or drug > causes of 2ry RLS include Iron deficiency, pregnancy, kidney disease, rheumatic disease and medications > 1ry RLS Pathophysiology is partially known and includes genteic component along with theories of dopamine and brain iron dysregulation Anaesthetic implications - RLS may worsen recur or present perioperatively - Common triggers include sleep deprivation and immobilisation - Drug therapy for RLS shopuld be continued perioperatively where possible - interuptions to treatment should be for the shortest time possible to prevent rebound effects - if imobilised for a long period of time, dopamine agonists such as rotigotone may be required - premedication with benzodiazepines or pregabalin may be useful - prolonged medical imaging procedures or procedures under local anaesthetic alone may not be possible. - post-op agitation 2ry to akathisia may be misinterpretted as delerium and treated with dopamine antagonists such as haloperidol which will worsen symptoms, Benzodiazepines should be used instead. Drugs that may exacerbate RLS 1. Classic neuroleptics - Haloperidol, prochlorperazine, promethazine 2. Atypical antipsychotics - clozapine, olanzapine, quetiapine 3. Antidepressants - amitriptyline, citalopram, lithium 4. Antihistamines - promethazine 5. Dopamine antagonist anti-emetics - metoclopramide 6. opioids - Tramadol (serotonin), naloxone/naltrexone (antagonists) > Opioids, oxycodone, fentanyl, morphine etc generally have a beneficial effect > IV anaesthetics, Inhalational anaesthetics, muscle relaxants, local anaesthetics, NSAIDs, Antiemetics have no effect Goals: 1. Prevent RLS exacerbation - avoid drug triggers - premedicate with benzos - use benzos for sedation - continue treatment for RLS - consider topical dopamine agonists when oral route unavailable 2. Alleviate post-op exacerbations - use parenteral opioids - Apomorphine - mobilise patient ASAP 3. Alleviate long-term exacerbation of RLS after surgery - monitor ferritin levels - If ferritin level < 75mcg/ml treat with oral or IV iron replacement - transiently increase dopamine agonist dose to TDS or QID if unable to leave bed

Answer 67

c) Embolic Blue Book 2017 Perioperative Stroke Epidemiology A perioperative stroke is defined as one that occurs either intra-operatively or in the post-operative period within 30 days70. Perioperative strokes are associated with an increased length of stay and a six-fold increased mortality. Any combination of surgery and anaesthesia is associated with an increased risk of stroke irrespective of the type of surgery. This may relate to coagulation changes The most common type of perioperative stroke is ischaemic stroke of embolic origin (heart or aorta). Hypotension is rarely the cause of perioperative stroke. Haemorrhagic stroke is uncommon which probably reflects the fact that severe hypertension during anaesthesia is a rare event, and anticoagulants have typically been withheld. The risk of perioperative stroke varies depending on the type of the surgery and patients’ risk factors. Procedural risk Urgent surgery is associated with an increased risk of stroke when compared to elective surger. Cardiac, vascular and brain surgeries are defined as “high-risk” as these have an increased risk of stroke when compared to other types of surgery. Valvular and aortic repair surgeries have a stroke risk as high as 8 to 10 per cent. Perioperative strokes in non-high-risk surgery are relatively rare and are estimated to have an incidence of about 1/1000 cases80. Patients’ risk factors >Age >history of previous stroke or transient ischaemic attack >renal failure >atrial fibrillation >history of cardiovascular diseases are identified risk factors for perioperative stroke. Atrial fibrillation is associated with a two-fold increase in the risk of death and stroke after carotid endarterectomy.

Answer 68

d. Urine osmolarity <100 DIAGNOSTIC CRITERIA >hypotonic hyponatraemia >urine osmolality > plasma osmolality (<275mOsm/kg) (i.e. concentrated urine despite hypotonic blood) >urinary Na+ > 20mmol/L >normal renal, hepatic, cardiac, pituitary, adrenal and thyroid function >euvolaemia (absence of hypotension, hypovolaemia, and oedema) correction by water restriction CAUSES (MAD CHOP) Major Surgery >abdominal >thoracic >transsphenoidal pituitary surgery (6-7 days post op) ADH production by tumours (Ectopic) >small cell bronchogenic carcinoma >adenocarcinoma of pancreas/duodenum >leukaemia >lymphoma >thymoma Drugs >antidepressants (e.g. SSRI, TCAs, MAOIs) >psychotropics (e.g. haloperidol, chlorpromazine), carbamazepine, Na+ valproate) >anaesthetic drugs (barbiturates, inhalational agents, oxytocin, opioids) >ADH analogues (vasopressin, DDAVP) >chemotherapy (e.g.Vinca alkaloids, Melphalan, Methotrexate and cyclophosphamide) >others (e.g. NSAIDs, amiodarone, ciprofloxacin, morphine, MDMA, proton pump inhibitors) CNS Disorders >cerebral trauma >brain tumour (primary or metastases) >meningitis/encephalitis >brain abscess >SAH >acute intermittent porphyria >SLE Hormone deficiency >hypothyroidism >adrenal insufficiency Others >Guillain-Barre Syndrome >HIV infection (early symptomatic or AIDS) >hereditary SIADH >giant cell arteritis >idiopathic (occult small cell or olfactory neuroblastoma) Pulmonary Disorders >pneumonia (viral, fungal, bacterial) >TB >lung abscess MANAGEMENT 1. see hyponatraemia 2. fluid restrict 3. incremental increase in Na+ if indicated to avoid central pontine myelinolysis 4. medications to decrease ADH secretion >Demeclocycline >Tolvaptan / Conivaptan

Answer 69

Labetalol RANZCOG first line drugs are > methyldopa > labetalol > oxprenolol. Second line agents are: - hydralazine - nifedipine - prazosin. Acute Rx: Labetalol: 20-40mg IV q10min Nifedipine 10-20mg PO Q45min Hydralazine 5-10mg IV q20min

Answer 70

C: 120ml/min An observational, prospective study comparing tibial and humeral intraosseous access using the EZ-IO. - humeral flow rates were significantly faster using a pressure bag (153 mL/min) compared with humeral those achieved without pressure bag (84 mL/min) - tibial flow rates to be significantly faster using a pressure bag (165 mL/min) compared with those achieved without a pressure bag (73 mL/min)

Answer 71

a. 3 Snoring loudly Tiredness during day time Observed Apnoea Pressure: Htn BMI > 35 Age > 50 Neck circumference >40cm (43cms male) Gender: Male

Answer 72

C. 3 - if male CHA2DS2-VASc score ≥2 to be recommended chronic OAC (Grade 1A). - if female CHA2DS2-VASc score ≥3 to be recommended chronic OAC (Grade 1A). * non-sex risk factor also holds bearing: - For patients with CHA2DS2-VASc score of 1 in males and 2 in females based on age 65 to 74 years, we recommend chronic OAC (Grade 1A). Up to date: Our approach to deciding whether to prescribe anticoagulant therapy for patients with AF (excluding those with rheumatic mitral stenosis that is severe or clinically significant [mitral valve area ≤1.5 cm2], a bioprosthetic valve [surgical or bioprosthetic] within the first three to six months after implantation, or a mechanical heart valve) is as follows: *For a CHA2DS2-VASc score ≥2 in males or ≥3 in females, we recommend chronic OAC (Grade 1A). *For a CHA2DS2-VASc score of 1 in males and 2 in females: -For patients with CHA2DS2-VASc score of 1 in males and 2 in females based on age 65 to 74 years, we recommend chronic OAC (Grade 1A). Age 65 to 74 years is a stronger risk factor than the other factors conferring one CHA2DS2-VASc score point. -For patients with other risk factors, the decision to anticoagulate is based upon the specific nonsex risk factor and the burden of AF. For patients with very low burden of AF (eg, AF that is well documented as limited to an isolated episode that may have been due to a reversible cause such as recent surgery, heavy alcohol ingestion, or sleep deprivation), it may be reasonable to forgo chronic OAC and institute close surveillance for recurrent AF, although it may not be possible to reliably estimate AF burden from surveying symptoms or infrequent monitoring. The frequency and duration of AF episodes vary widely over time, and episodes are often asymptomatic. *For patients with a CHA2DS2-VASc of 0 in males or 1 in females, we suggest against OAC (Grade 2C). Patient values and preferences may impact the decision. For example, a patient who is particularly stroke averse and is not at increased risk for bleeding may reasonably choose anticoagulation, particularly if the patient is a candidate for treatment with a direct oral anticoagulant (DOAC). 2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline