FCA 2020 Flashcards
Question 1 A 20-year-old healthy male is involved in a motor vehicle collision. He sustains facial injuries including maxillary fractures. With regard to intubation choices, fill in the table below. [10]
Question 2 a) List 5 personal attributes required of a medical professional and specialist anaesthesiologist in the clinical context.
As senior consultant, you welcome a new colleague into your department. He asks your advice in terms of self-organisation and self-management. How would you advise him about the requirements for practising full time in a public institution?
a) List the ideal anaesthetic conditions for corneal transplant surgery.
What are your concerns with regards to the use of suxamethonium in corneal transplant surgery?
Name two regional anaesthetic blocks that may be used for corneal transplant surgery. (1)
Which component of regional anaesthetic blocks for ocular surgery may affect intraocular pressure?
What are the limitations of using regional anaesthesia for corneal transplant surgery? (2)
Question 4 a) Briefly outline the preoperative and intraoperative factors and pathophysiological processes that may contribute to the acute coagulopathy that develops during major vascular surgery.
List three point of care tests that may help to elucidate the cause of the acute coagulopathy during major vascular surgery.
Question 5 An unbooked 24-year-old patient presents to your tertiary hospital in active labour and foetal distress. She has differential cyanosis with clubbing of the toes. The diagnosis of a longstanding Patent Ductus Arteriosus (PDA) is made clinically by the cardiologist. a) Name 4 cardiovascular changes during normal pregnancy at term relevant to this patient.
Increased blood 35% and plasma volume 55%
Increase cardiac output 40%
Reduction in systemic vascular resistance 15% pulmonary vascular resistance 30%
What monitoring is needed above the standard monitoring?
A-line
CVP
Briefly explain the main reasoning behind your chosen anaesthesia technique.
Patient WHO class one with no detectable increased risk of maternal mortality and no/mild morbidity.
Spinal anesthesia
• Reduce SVR limit left to right shunt
• Thus reduce increases in pulmonary blood flow
• Avoids airway manipulation in high risk for aspiration and possibly difficult airway patient
• Avoids blood pressure swings with sympathetic activation during laryngoscopy and extubation, hypotension post induction.
• Better pain score
• Lower risk of DVT
• patient satisfaction
Question 6
A term infant born 6 hours ago presents with respiratory distress and a saturation of 82% on nasal prongs. He is diagnosed with congenital diaphragmatic hernia. a) When would be the ideal time to correct the hernia surgically?
Inutero for those with LHR low and predicted to have poor outcomes
○ Recommendations from the CDH EURO Consortium state that the following physiological parameters should be met before surgery:
(i) mean arterial pressure normal for gestation,
(ii) preductal oxygen saturation consistently 85-95% on FiO2 <0.5,
(iii) lactate below 3 mmol litre1, and
(iv) urine output more than 1 ml kg/hr.
Question 6 A term infant born 6 hours ago presents with respiratory distress and a saturation of 82% on nasal prongs. He is diagnosed with congenital diaphragmatic hernia. b) List all the factors likely to contribute to the hypoxia
• Affected lung is intrinsically abnormal
• Under-developed airways
• Abnormal differentiation of type II pneumocytes
• ↓ number of pulmonary arteries per unit lung volume
• Intrapulmonary arteries become excessively muscularized with thickened adventitia & media
& muscularization extends peripherally
• Pulmonary vessels display exaggerated response to vasoactive subs
Question 6 A term infant born 6 hours ago presents with respiratory distress and a saturation of 82% on nasal prongs. He is diagnosed with congenital diaphragmatic hernia.
c) Briefly discuss how the anaesthetist should avoid worsening of the hypoxia in the perioperative period.
- Optimisation of ventilation
- Maintain cardiac output, give 10ml/kg bolus x2 with ionotropic support to maintain MAP
- Prevent pulmonary hypertension exacerbation by warmining, prevent excessive hypercarbia, give adequate oxygen, maintain PH >7,25
- Pulmonary vasodilators
- Ventilation aims
Preductal SpO2 between 85% to 95%
○ Postductal SpO2 > 70%
PIP < 25 cmH2O with a ○ PEEP set between 3 to 5 cmH2O
FiO2 < 50%, titrated to preductal SpO2 goals
Respiratory rate between 40 to 60 breaths per minute
PaCO2 between 50 to 70 mm Hg
the pH of 7.25 and above
ECMO INDICATIONS
○ Preductal SpO2 < 85% or postductal SpO2 < 70%
PaO2 < 40 mm Hg
Mixed venous saturation < 60%
Oxygenation index > 40 for at least 3 hours
Mixed acidosis pH < 7.2 with hemodynamic instability
Requiring PIP > 28 cmH2O or MAwP > 15 cmH2O to maintain oxygenation
Lactate > 5 mmol/L with a pH < 7.2
Hypotension refractory to fluids and pressors
Severe air leak and requiring high ventilatory settings
Question 7 A 38-year-old woman with a diagnosis of acute appendicitis undergoes an open appendicectomy under general anaesthesia. She is known with idiopathic pulmonary arterial hypertension of 10 years duration managed on home oxygen therapy and sildenafil 50mg 6 hourly. A recent work-up for lung transplantation measured her mean pulmonary arterial pressure at 57mmHg. Intra-operatively her oxygen saturations (SaO2) range between 89% and 91% on an FiO2 of 0.60. Towards the end of the procedure her SaO2 rapidly decreases to 68% despite an increase in FiO2 to 1.0. Her ventilation pressures and end-tidal CO2 remain within normal limits. a) What is the likely aetiology of this patient’s clinical deterioration?
b) Name ONE monitoring modality, other than basic and arterial blood pressure monitors, that would help in the diagnosis and management of this episode. (PULMONARY HPT) (1)
c) List the drugs you could use to treat this evolving clinical scenario (assume all are readily available). Briefly describe their mechanisms of action (pulmonary hypertension exacerbation with hypoxia intraoperative)
Question 8 A 5-year-old boy with a history of unrepaired tetralogy of Fallot (TOF) is seen in the emergency unit complaining of headache after a seizure at home. High definition computed tomography without contrast reveals a lesion suggestive of an abscess in the right temporo-parietal region with significant midline shift. On examination he is awake and oriented with no focal deficits. He has no papilloedema. He is pyrexial (38.4°C), clubbed and centrally cyanosed. He weighs 12kg and has an Hb of 16.2g/dl. The patient is booked for an urgent craniotomy for abscess drainage. a) Briefly describe your perioperative anaesthetic management of this patient?
Question 9
During a pre-operative visit for a patient presenting for a laparotomy, the patient tells you he was diagnosed with porphyria at a young age. He mentions that tests were done and he was told he has
an acute type of porphyria.
a) The acute types of porphyria can complicate into acute neurovisceral crisis.
i) List 4 triggers for acute neurovisceral crisis in the perioperative period. (2)
TRIGGERS:
- fasting
- dehydration
- infection
- drugs
- endogenous hormones
- stress (physical/emotional)
- smoking
- alcohol
ii) List 2 cardiovascular symptoms that manifests during an acute crisis porphyria. (1)
Tachycardia
Tachyarrhythmia
Hypertension
List the 3 mechanisms of drug porphyrinogenicity.
c) How will you manage an acute porphyria crisis? (4)
Supportive Measures:
1. Immediate cessation of any medication that is not known to be safe in porphyria
2. Pain management: patients require frequent, high doses of opiate analgesia as pain is severe and recurs after a short interval. Opiate dependence in acute porphyria is rare as the need for high, frequent doses of opiates is genuinely in response to excruciating pain.
Recommended analgesic agents:
- Pethidine: patients may require 50-100mg hourly
- Morphine
Drugs to avoid:
- Antispasmodics (e.g. Hyoscine butylbromide)
- These may precipitate an acute attack.
3. Vomiting and Nausea: Recommended antiemetics:
- Metoclopramide, prochlorperazine
4. Hypertension and Tachycardia: hypertension is usually mild and subsides without specific treatment. In cases of severe hypertension Beta-adrenergic and Alpha-adrenergic blockers can be used. Beta-blockers are, in themselves, anti-porphyrinogenic and are
therefore beneficial. Magnesium sulphate may also be added in the rare event of severe hypertension not responding to Beta and Alpha-adrenergic blockers.
5. Fluid therapy and Carbohydrate intake(15)
.
Patients with acute porphyria are often dehydrated due to vomiting and poor oral intake.
Electrolyte imbalance is also common. These include: hyponatremia, hypomagnesemia
and hypokalaemia. Decreased caloric intake may precipitate or worsen an acute porphyric
crisis. Therefore, an adequate fluid and carbohydrate intake is important.
Recommended Fluid Therapy:
- 5% Dextrose Saline (2 litres will provide 100g of glucose a day)
- As soon as patients are able to tolerate oral intake the should be transferred to a diet in
which carbohydrates provide 55-60% of the energy needed to maintain their normal
weight.
6. Seizures: Seizures may be due to the neuropathy caused by the disease itself orsecondary to the electrolyte abnormalities that may occur.
Recommended drug therapy:
- Clonazepam and Diazepam
7. Psychosis: chlorpromazine is suitable in the treatment of psychosis.
8. Correct electrolyte imbalances.
9. Investigate for and treat infections
Specific Treatment:
40% of Acute Attacks, especially those occurring in patients with Variegate Porphyria, will
resolve with supportive management alone. Patients with severe attacks, recurrent
episodes or patients that show no improvement after 24 hours require specific treatment.
1. Haem Arginate vs Haematin
Typically, haem therapy has been given in the form of hematite which consists of haem
dissolved in alkali. This solution, however, is unstable and rapidly decomposes. The
resultant degradation products are said to be responsible for some of the adverse
reactions seen with the use of Haematin. Haem complexed with the amino acid arginine
forms the stable compound: Haem araginate. Both Haematin and Haem arginate works
by replenishing haem stores and thereby inhibiting ALA synthetase by the negative
feedback mechanism. Further build up of porphyrins are therefore prevented.
Complications:
- Phlebitis at the site of injection has been reported with the use of Haem arginate: this
can be reduced by diluting the drug in human serum or human serum albumin which
acts as a protein buffer.
- Phlebitis has also been noted with the use of Haematin as well as dose-related,
reversible renal shutdown and thrombocytopenia and coagulopathy.
Disadvantages:
- Haem arginate is extremely expensive (currently costs around R20000 for 4 ampoules)
However, the dramatic clinical improvement and shortened hospital stay with a course of
haem arginate therapy as compared to long term hospitalisation and rehabilitation without
haem arginate, makes haem arginate highly cost effective.
Ways in which to minimise cost include:
- Reserving treatment for patients with severe acute porphyric attack, recurrent episodes
or no improvement after 24 hours, with conservative management. It is reasonable to
closely observe patients for 24 hours and treat with supportive measures before deciding
to commence treatment with Haem arginate.
- Using a standard dose of 5ml per dose (instead of the 3mg/kg/day advised on the
package insert). Each vial contains 10ml. The standard dose has been shown to be
effective.
- It is vitally important that haem arginate is given before neuropathy develops as it does
not reverse already established neuropathy.
- Haem arginate is not FDA approved.
- Haematin is extremely unstable.
Question 10
A 59-year-old male is booked for the resection of the upper right lung lobe. The surgeon requests
that you provide lung isolation to facilitate the surgery.
a) Name and briefly describe three lung isolation techniques applicable to this scenario. (6
- Double lumen ETT:
° allows the greatest control over switching from dual lung ventilation to
single lung at various stages of a procedure.
° They also allow suctioning of individual lungs and the administration of CPAP/PEEP to individual lungs.
° They are available in left and right sided forms, but all utilize a tracheal and bronchial cuff.
° They are larger and longer that standard endo-tracheal tubes.
° The DLT is inserted with the bronchial lumen curved anteriorly, and once through the laryngeal inlet, requires a 70-90
degree rotation. For this reason they may be more difficult to insert than a standard endo-tracheal tube. This
means that they may not be suitable for patients with difficult airways, or in patients at risk of aspiration.
° They are not suitable for patients under 35kg in weight. Due to the reduced internal diameter of each lumen they may
present a considerable increase in airway resistance in a spontaneously breathing patient.
° Left sided DLT’s are more commonly employed than their right sided equivalents (unless significant left sided
lung resection, or a left pneumonectomy is planned). This is due to the difficulties in ensuring that the right double lumen tube is correctly positioned to prevent occlusion of the right upper lobe bronchus, which would result in failure to ventilate the right upper lobe, risking intraoperative hypoxia and atelectasis but I this case is the best considering the operative site is the right upper lobe. - Bronchial blocker
The main bronchi may be isolated by the introduction of fogarty embolectomy or foley catheters into the main
bronchi, and inflating the balloons. In small or paediatric patients a pulmonary artery floatation (Swan-Ganz)
catheter can be employed. Correct positioning of the balloons may be difficult and this technique does not allow
suctioning or ventilation of the isolated lung - Endobronchial single ETT
The quickest and easiest way to isolate an individual lung is to introduce a standard endotracheal tube into one
of the main bronchi. When more specialist equipment is not readily at hand or in order to isolate a lung in an
emergency this may represent the most appropriate technique. However when compared to more advanced
techniques it has a higher rate of bronchial damage and in the event of hypoxic episodes treatment options are
more limited.
b) The patient develops hypoxaemia and the airway pressures increase significantly 15 minutes after the start of one lung ventilation. Name two possible causes of the hypoxaemia in this context and what action you will take to address each cause. (4)
On initiation of one lung ventilation (OLV), the primary physiological change that takes place is perfusion of
the non dependent lung without ventilation, effectively causing a large shunt
However, this degree of shunt is reduced by gravity causing decreased blood flow to the non-dependent lung, and is further diminished by a
phenomenon termed hypoxic pulmonary vasoconstriction (HPV). The mechanism of HPV is not fully
understood but is either as a direct response to regional alveolar and mixed venous hypoxia, or due to the
release of vasoactive substances during hypoxia, causing vasoconstriction in the pulmonary blood vessels.
In terms of anaesthetic technique volatile agents and direct vasodilators directly inhibit pulmonary
vasoconstriction. Interestingly vasoconstrictive drugs such as Noradrenalin preferentially constrict the vascular
beds in areas of the lung with normal oxygen tensions, which indirectly inhibits pulmonary vasoconstriction.
Management:
• Administer 100% Oxygen
• Check Ventilator, Circuit and catheter mount
• Clear secretions and debris by suctioning dependent lung
• Check tube position
• Apply CPAP or entrain Oxygen to non dependent lung
• Perform recruitment manoeuvre and apply PEEP to dependent lung
• Revert to two lung ventilation
• Clamp non-dependent pulmonary artery
Question 11
a) In consenting a patient for a labour epidural how would you quantify the risks for the following
complications:
i) Temporary nerve damage. (1)
1:1000-2000
ii) Permanent nerve damage. (1)
1:24000 Rare
iii) Dural puncture. (1)
iv) Failure. (1)
1:10 common
b) List three precautions that you would take to mitigate the risk of the catheter migrating. (3)
- Saline or air loss of resistance techniques
- Aspirate or gravity assistance to detect csf
- Not advance beyond 4cm
- Avoid microcatheters
- Test dose
c) A patient experiences pain during the second stage of labour despite a well-functioning epidural in the first stage that is still correctly positioned and running at an adequate infusion
rate? Give two reasons for this
○ Pain is transmitted in the second stage somatic via the pudendal nerves to the second, third and fourth sacral segments of the spinal cord, this is not usually in close proximity to the epidural catheter insertion level and therefore the epidural solution has some distance to travel to reach these sacral nerves. This makes it less likely that the associated dermatomal areas will be adequately blocked unless
there is an increase in volume of epidural solution injected. Therefore the
epidural will be rendered less effective during the second stage of labour than
it was during the first
Question 12
a) A 2-day-old term neonate with a weight of 2.4kg presents for a repair of a myelomeningocoele (MMC). There are no other congenital abnormalities.
i) Compare (give values) in the cerebral metabolic rate of O2 consumption (CMRO2) and cerebral blood flow (CBF) in this patient and an adult.
Question 12 a) A 2-day-old term neonate with a weight of 2.4kg presents for a repair of a myelomeningocoele (MMC). There are no other congenital abnormalities. i) Compare (give values) in the cerebral metabolic rate of O2 consumption (CMRO2) and cerebral blood flow (CBF) in this patient and an adult.
Global CMR for oxygen and glucose is higher in children than in adults (oxygen 5.8 vs. 3.5 mL/100 g brain tissue/min and glucose 6.8 vs.5.5 mL/100 g brain tissue/min, respectively)
Similar to CMRO2, cerebral metabolic rate for glucose (CMRglu) is lower at birth (13 to 25 µmol/100 g/min), increases during childhood, peaks by 3 to 4 years of age (49 to 65 µmol/100 g/min), and remains high until 9 years of age
Neonates have a lower CMRO2 (2.3 ml 100 g21 min21) and a lower CBF, with a relative tolerance of hypoxaemia.
iii) List two precautions during induction that you could take to avoid compression or rupture of the MMC
Use doughnut shaped support
Induction and intubation in lateral position
b) With regards to the positioning of the patient for the surgery, what precaution would you take to avoid venous congestion of the surgical site? (2)
Neuroprotective strategies: temp control, pC02 management, maintaining CPP, O2 adequate level
Neonates have a lower CMRO2 (2.3 ml 100 g21 min21) and a lower CBF, with a relative tolerance of hypoxaemia.
Define VAP
Pneumonia ≥ 48hrs after intubation
° early onset < 4/7 Strep/Haem,
° late onset > 4/7 Pseudomonas/MRSA/gram⊖basilli)
How is VAP diagnosed
Johannson Criteria
•New/worsening CXR infiltrates
+ >2
1.Temp > 38º
2.Leukocytosis
3.Purulent secretions
Clinical Pulm Inf Score (CPIS)
•Points > 6/12 = VAP
•Scoring 0-2
1.Temp > 36.5-39
2.Leukocytes
3.Secretions
4.CXR
5.Culture results
6.PaO2:FiO2 ratio
2013 CDC VAE/VAC Criteria
•Vent Associated Event/Condition
•
1.VAC=↑vent requirements
2.Infection related VAC (IVAC) = VAC + temp/WCC/Antibiotics
3.Possible pneumonia = IVAC + secr/culture⊕
4.Probable pneumonia = IVAC + secretions + culture⊕/legionella/histopathology/pl fluid
HELICS Crit Based on findings: Radiological Systemic Pulmonary
Briefly outline strategies for the prevention of VAP
VAP BUNDLE for prevention of VAP
A.Head up
B.Daily sedation holds +Spontaneous breathing trials
C.Oral hygiene - wash/suction
D.Cuff pressure 20-30cmH2O
E.Subglottic secretion drainage/tapered cuff F.ETT internal coating (Silver or other)
G.Hand + equipment hygiene
H.Ulcer prophylaxis only for high risk pts
I.?Postpyloric feeding ?Probiotics
Question 15
An 80-year-old male patient presents for endovascular repair of his 5,8cm infrarenal abdominal aortic aneurysm. He is known with hypertension that was complicated by a transient ischaemic attack which left no neurological fallout. He also has a 30-pack year history of smoking.
a) What is his annual risk of rupture and why is this important?
Question 15 An 80-year-old male patient presents for endovascular repair of his 5,8cm infrarenal abdominal aortic aneurysm. He is known with hypertension that was complicated by a transient ischaemic attack which left no neurological fallout. He also has a 30-pack year history of smoking.
a) What is his annual risk of rupture and why is this important?
Diameter (cm)=Rupture risk (%/yr)
< 4=0
4-5=0.5-5
5-6=3-15
6-7=10-20
7-8=20-40
> 8=30-50
Name two risk factors for spinal cord ischaemia and how would you try to prevent it? (2) (½ a mark for any one of these risk factors and 1 mark for preventative measure). (2)
Risk factors for spinal cord ischaemia include the extent of the aneurysm;
1. longer duration of aortic cross-clamping;
2. requirement for emergency surgery;
3. previous surgery to the distal aorta;
4. severe peripheral vascular and atherosclerotic disease;
5. perioperative hypotension;
6. advanced age; and
7. diabetes mellitus.15
○ reduce the risk of spinal cord ischaemia, including
1. sequential clamping of the aorta with reimplantation of intercostal and lumbar segmental vessels,
2. drainage of CSF to maintain SCPP, and
3. the use of neurophysiological monitoring.
4. Physiology of left heart bypassThis ensures continued perfusion of organs distal to the clamp and relief of left ventricular afterload
Question 16 A vascular surgery registrar has requested a pre-operative consultation for a 66-year-old male patient scheduled for an aorto-bifemoral bypass procedure. He is known with: • Insulin dependent diabetes mellitus – well controlled with an HbA1c of 6% • A history of a myocardial infarction 1 year ago after which he had an angioplasty done and is currently asymptomatic • Atrial fibrillation that is rate controlled. His current METS is > 4 Current medications include: - Aspirin 150mg dly po - Protophane 30u mane and 20u nocte sc - Dabigatran 150mg b.d po - Diltiazem SR 90mg b.d po - Digoxin 0.25mg dly po a) What is his risk for developing an adverse event post-operatively and why?
b) The registrar wants to know what to do with the following drugs pre-operatively and why? i) Dabigatran. (2)
Digoxin
Diltiazem
c) Would you start this patient on a beta blocker preoperatively? Motivate your answer. (2)
Question 17 a) You are required to anaesthetise a 22-year-old male for debridement of a small necrotic area of skin and superficial tissue related to a subclavian central line. The patient is recovering in a normal medical ward following an ICU stay for severe Guillian-Barre polyneuropathy complicated by need for respiratory support, ventilator acquired pneumonia and severe sepsis. He was ventilator dependent for 19 days. What would be your concerns regarding neuromuscular blocker (muscle relaxants) in this patient. (6)
Altered response to neuromuscular blocking drugs (NMBs):
Succinylcholine contraindicated due to hyperkalemia risk
NdMR (nondepolarizing muscle relaxant)sensitivity
b) What would be your choice of airway management in this patient, for a 30 minute procedure? Give reasons explaining your choice.
ETT
°Site of operation
°
Question18 You are tasked with decreasing the risk of surgical site infection in your hospital. a) Name a quality improvement method, whose steps you would use. (1)
b) Briefly describe your approach using one of the accepted quality improvement tools available, explaining the steps
Question 19 You are required to anaesthetise a patient for electroconvulsive therapy (ECT) in the psychiatric ward procedure room. a) What are the challenges of anaesthetising this patient in the designated area?
b) What other issues do you need to bear in mind when anaesthetising this patient? (7)
A patient presents on the emergency list with a stab wound to the abdomen for an exploratory know laparotomy. His brother mentions that he is known to be a substance abuser, but he does not any further details. How does this history of substance abuse impact your anaesthetic plan ? [ 10
Question 1 35 Figure 1 shows an intraaortic pressure curve (PC) with corresponding EKG. Bullets 1, 2, and the PC represent the dicrotic notch, the aorta enddiastolic pressure, and the aorta peak 3 on systolic pressure, respectively. A decision is taken to provide mechanical circulatory support utilizing an intra– aortic balloon pump (IABP). Following proper s triggered by the Rwave of ev ery 3 rd etup, a ratio of 1:3 is selected, i.e. the IABP is QRS complex. The IABP is switched on at the point indicated by the asterisk (*) corresponding to the RFigure 1. wave of the 4 th QRS complex from the left, as shown i
