Random FFICM Questions Flashcards
(130 cards)
1
Q
What causes a high mixed venous oxygen saturation (SvO2)?
A
↑ SvO2
• ↑ O2 delivery, e.g.
↑ FiO2, hyperbaric O2
• ↓ O2 extraction,
e.g. hypothermia, general anaesthetic, neuromuscular blockade
• ↑ Flow states, e.g. sepsis, thyrotoxicosis, severe liver disease
2
Q
What causes a low mixed venous oxygen saturation (SvO2)?
A
↓ SvO2
• ↓ O2 delivery, e.g. shock states, hypoxemia, anaemia
• ↑ O2 extraction, e.g. hyperthermia, shivering, pain, seizures
3
Q
What is a mixed venous oxygen saturation (SvO2)?
A
SvO2 is obtained from a pulmonary artery catheter. It measures the end result of O2 consumption and delivery, and contains blood from both the SVC and IVC. The normal range is approximately 65–70%.
4
Q
What is ScvO2?
A
ScvO2 measures oxygen saturation in the SVC, taken from an internal jugular, subclavian or axillary vein catheter and is sometimes used as a surrogate for SvO2.
5
Q
What is the relationship between SvO2 and ScvO2?
A
Typically, in healthy individuals, SvO2 > ScvO2 because the brain (SVC-drained) has a higher oxygen demand compared to organs like the kidneys (IVC-drained) with lower oxygen demands.
ScvO2 can surpass SvO2 in cases where the brain’s metabolic requirement decreases, such as during anaesthesia, in TBI, or in shock, when body oxygen extraction increases, which leads to reduced oxygen saturation in the IVC.
6
Q
What is functional residual capacity (FRC)?
A
• FRC = expiratory reserve volume + residual volume.
• It is the volume of air in the lungs after normal expiration, measured by either gas dilution or body plethysmography.
7
Q
What factors affect functional residual capacity (FRC)?
A
↑ FRC :
• Standing position
• Asthma/COPD
• PEEP/CPAP
↓ FRC
• Supine position
• Obesity
• Pregnancy
• Restrictive lung disorders
• General anaesthesia
8
Q
What should be the normal cuff pressure of a tracheostomy and how often should it be checked and why?
A
20–30 cm H2O
It should be checked every 8–12 hours, (or more frequently depending on the clinical picture)
Higher cuff pressures may compress tracheal capillaries, limit blood flow, and predispose to tracheal necrosis (ischaemic damage).
9
Q
What is the difference between cardiac output and cardiac index and what are their normal values?
A
• Cardiac Output = Heart Rate × Stroke Volume
Normal range ~ 4–8 L/min
• Cardiac Index = Cardiac Output/Body
Surface Area
Normal range ~ 2.5–4 L/min
10
Q
What is the physiological role of C‐reactive protein?
A
• A pentraxin protein synthesised in the liver
• ↑ In response to inflammation
• Binds to phosphocholine on the surface of dead/dying cells, which activates the complement system
11
Q
Which cardiac structural abnormality may the presence of a right bundle branch block in a young adult indicate?
A
Atrial septal defect
12
Q
What are some of the causes of a raised MCV?
A
DRAMATIC
D - Drugs, e.g. anticonvulsants, antimicrobials, chemotherapy
R - Reticulocytosis
A - Alcohol abuse
M - Megaloblastic anaemia, e.g. pernicious anaemia, B12/folate deficiency
A- Artefact, e.g. aplasia, myelofibrosis, hyperglycaemia, cold agglutinins
T - Thyroid (hypothyroidism)
I - Immature bone marrow cells, e.g. myelodysplastic syndrome
C - Chronic liver disease
13
Q
What is the dose of IV salbutamol in treating life‐threatening asthma, and what are some side effects?
A
• Dose: 3–20 mcg/min
• Side effects: tachycardia, arrhythmias,
tremors, hyperglycaemia, hypokalaemia, and type B lactic acidosis
14
Q
What are the mechanisms of drug‐induced hyperkalaemia?
A
K+ supplements
• Sando-K
• IV fluids with K+
Drugs that impair K+ distribution
• Beta blockers
• Arginine
• Digoxin
• Suxamethonium
Drugs that ↓ renal K+ excretion
• Calcineurin inhibitors, e.g. tacrolimus and ciclosporin
• Potassium-sparing diuretics,
e.g. spironolactone,
eplerenone
• Some antibiotics, e.g.
trimethoprim
Drugs that impact on the RAAS
• NSAIDs
• ACE inhibitors, ARBs
• Heparin
15
Q
When do you control hypertension in the first 24 hours after an acute ischaemic stroke according to NICE?
A
NICE advises against actively managing hypertension during this period, except in the following situations:
• To facilitate thrombolysis–target BP < 185/110.
• In cases of pre-eclampsia, aortic dissection, or hypertensive encephalopathy/nephropathy/cardiac failure.
16
Q
What percentage TBSA burn would meet the criteria for referral to a burns centre on area alone?
A
> 40% Total Body Surface Area (TBSA)
17
Q
Where is propofol predominantly metabolised?
A
Liver: Hepatic metabolism, primarily via glucuronidation and sulfation pathways.
18
Q
What is the dose of IV magnesium in the management of acute asthma, and how does it work as a bronchodilator?
A
Dose:
1.2–2 g IV over 20 minutes
Mechanism as a bronchodilator:
1. Calcium blocker in bronchial smooth muscle
2. ↓ Ach release at the NMJ
3. ↑ Sensitivity of β-receptors to catecholamines
19
Q
What is the Parkland formula for IV fluid replacement after a burn, and does it take into account pre-hospital fluid administration?
A
4 mL/kg/%TBSA over 24 hours
Half of total is given in the first 8 hours after the injury.
When calculating TBSA, erythematous regions are omitted unless there is additional blistering or underlying evidence of a partial- thickness burn.
This formula takes into account pre- hospital fluid administration. Therefore, any prehospital fluid is subtracted from total.
Aiming for 0.5ml/kg/hour urine output
20
Q
What did the PROPPR trial (2015) demonstrate for blood product administration in a 1:1:1 ratio compared to a 1:1:2 plasma:platelet:red
cell ratio in patients with severe trauma and major bleeding?
A
• No difference in all-cause 24-hour or 90-day mortality
• Post-hoc analysis found a significant reduction in death by exsanguination within the first 24 hours and a higher rate of achieving haemostasis in the 1:1:1 group compared to the 1:1:2 group.
21
Q
What are the 12 physiological variables of the APACHE II score, how do you calculate the score and what does it mean?
A
CNS:
GCS
CVS:
MAP
HR
Resp:
RR
PaO2
Renal:
Arterial pH
Na+
K+
Creatinine
Micro/Haem:
Temperature
WCC
Hct
The worst of these variables within the first 24 hours of critical care admission is used
Effects of age and chronic health are incorporated to give a single score with a maximum of 71. A score of >25 represents a predicted mortality of >50%.
22
Q
What dose of adrenaline do you give in adult anaphylaxis?
A
IM: 0.5–1mL of 1:1,000 (0.5–1mg)
OR
IV: 0.5–1mL of 1:10,000 (50–100 mcg)
23
Q
What is the difference between intra‐ abdominal hypertension (IAH) and abdominal compartment syndrome (ACS), and how do you measure intra-abdominal pressure (IAP)?
A
• IAH: sustained or repeated pathological elevation of IAP ≥ 12 mmHg
• ACS: sustained IAP > 20 mmHg + new organ dysfunction/failure +/− abdominal perfusion pressure (APP) < 60 mmHg
IAP is measured:
• Direct: puncture of the abdominal cavity
• Indirect: via a urinary catheter in the bladder or a balloon-tipped catheter inserted into the stomach. Correlates well with direct measurements but can be inaccurate when there are adhesions, pelvic fractures, and abdominal packs.
24
Q
Where in adults does the trachea start and divide anatomically?
A
• Starts at C6
• Extends to T4 where it bifurcates
• It is approximately 10–12 cm long
• The right main bronchus separates at a
25° angle and the left main bronchus separates at a 45° angle.
25
What is the evidence for a decompressive hemicraniectomy (DH) in malignant middle cerebral artery syndrome according to the DECIMAL (2007), HAMLET (2009) and DESTINY II (2011) trials?
• Mortality: Decompressive hemicraniectomy significantly reduces mortality compared to conservative treatment in all three studies. This benefit appears to be particularly strong when surgery is performed early (within 48 hours) after stroke onset.
This was observed in younger patients (18–55 years in DECIMAL) and older patients (≥61 years in DESTINY II), as well as in the varied population of HAMLET.
• Neurological Disability: The findings on functional outcome are more complex and are potentially dependent on factors like age, stroke severity, and time to surgery:
Decompressive hemicraniectomy did not significantly improve the proportion of patients achieving a ‘good’ functional outcome (mRS ≤ 3) at 6 or 12 months in DECIMAL and HAMLET.
However, it significantly increased the proportion of patients achieving a ‘moderate’ functional outcome (mRS ≤ 4) at six months in DECIMAL and DESTINY II.
Notably, no surviving patients in DESTINY II achieved the best possible functional outcome (mRS 0–2).
Overall: Decompressive hemicraniectomy offers a clear and substantial mortality benefit. While it may not guarantee good recovery and return to pre-stroke levels of function, it can increase the chances of achieving moderate disability as opposed to severe disability or death. This decision requires individualised assessment and MDT involvement.
26
How do you distinguish between moderate, severe and life-threatening acute asthma?
Moderate PEFR > 50%
No features of severe asthma
Severe PEFR 33–50%
RR ≥ 25
HR ≥ 110
Inability to complete sentences in one breath
Life‐threatening
Features of severe asthma + at least one of:
• PEFR < 33%
• SpO2<92%
• Normal or ↓ PCO2: implies poor ventilation
• Cyanosis, confusion or coma
• Hypotension or ↓ HR
• Exhaustion or poor
respiratory effort
• Silent chest
• Tachy(arrhythmia)
27
When is it safe to use suxamethonium after a significant burn injury?
• Within the first 24 hours after the burn
• One year after the burn
28
How do you calculate the internal diameter of an endotracheal tube in the paediatric population?
Cuffed : [age / 4] + 3.5
Uncuffed : [age / 4] + 3.5 + 0.5
29
What is the recommended therapeutic management for a variceal haemorrhage that continues to bleed despite pharmacological intervention, endoscopic banding and balloon tamponade?
Transjugular Intrahepatic Portosystemic Shunt (TIPS)
30
When is damage control surgery more preferable than definite surgery in trauma?
When there is severe haemorrhagic shock and/or ongoing bleeding.
This is particularly necessary if the lethal diamond is present (hypothermia, acidosis, coagulopathy and hypocalcaemia) and in patients who have inaccessible major venous injuries or those who require time-consuming procedures.
31
What risk is associated with the administration of suxamethonium after a spinal cord injury, and how soon after the injury does this risk occur?
• Life-threatening hyperkalaemia
• 72 hours after spinal cord injury
32
How is the rapid shallow breathing index (RSBI) useful as a weaning predictor?
RSBI = RR / Tv (TV in Litres not mls)
• RSBI < 105: 80% chance of successful extubation
• RSBI >105: strongly suggests weaning failure
33
What happens to pulmonary artery pressure after a cardiac arrest?
↑
Multifactorial reasons why this may occur include:
Post-ROSC
o ↑ PVR secondary to hypoxia/acidosis o ↑ PAP secondary to cardiac dysfunction as part of post-cardiac
arrest syndrome
Precipitant of cardiac arrest
o ↑ PAP secondary to cardiac
dysfunction (e.g. STEMI) or pulmonary embolism
34
What is meant by intention to treat analysis in a randomised controlled trial?
• All participants are analysed based on their originally assigned treatment groups, regardless of whether they completed or received the intended treatment.
• This approach helps maintain the randomisation and avoids biases caused by crossover or dropout.
35
Which clinical features in someone with a burn may indicate the need for early intubation?
• GCS<8
• Respiratory distress or failure
• Noticeable swelling or blistering in the lips, tongue or oropharynx
• Voice changes, e.g. hoarseness or stridor
• Singed nasal hair
• Carbonaceous sputum
• Extensive burns of the face or neck,
including circumferential burns
36
How does digoxin work in treating atrial fibrillation with a fast ventricular rate?
Direct:
Inhibits cardiac Na+/ K+-ATPase causing an
↑ Intracellular Na+ which leads to
Exchange of Na+ for Ca2+ via the Na+/Ca2+ pump causing
↑ Intracellular Ca2+ and↓ Intracellular Na+
↑ Intracellular Ca2+ causes ↑ cardiac contraction
↓ Intracellular Na+ prolongs refractory time of the bundle of His
Indirect:
↑ Acetylcholine at cardiac muscarinic receptors
Resulting in prolongation of the refractory period at the AV node and bundle of His
37
Which alternative drug can be used in the management of AVNRT if adenosine is contraindicated?
Verapamil 2.5–5 mg IV
38
Why may someone with primary hyperaldosteronism (Conn’s syndrome) develop muscle weakness and tetany?
Due to hypokalaemic metabolic alkalosis
Conn’s syndrome causes a low renin hypertension.
It is diagnosed by a ↑ aldosterone:renin ratio.
39
What modifications have been implemented in advanced life support algorithms for resuscitating individuals with hypothermia?
• Refrain from administering adrenaline or any other drugs until the temperature is >30°C.
• When the temperature ranges from 30°C to 35°C, double the dose intervals for ALS drugs.
• In cases of VF, consider delivering up to three shocks if needed, but hold off on further shocks until the temperature is >30°C.
40
What is the most likely diagnosis if someone develops hypocalcaemia and seizures two days after starting chemotherapy?
Tumour lysis syndrome (TLS) – electrolyte abnormalities can precipitate neurological dysfunction.
41
What are the common biochemical abnormalities seen in tumour lysis syndrome?
Common abnormalities include:
• ↓ Calcium
• ↑ Phosphate, potassium, urate, LDH,
lactate
42
What causes and what cancers are associated with Tumour Lysis Syndrome?
TLS is due to the sudden and large-scale death of cells following the initiation of chemotherapy. It is often associated with acute leukaemias and high-grade lymphomas, e.g. Burkitt's.
43
What are the most likely causes for developing drowsiness one week after undergoing endovascular coiling for a subarachnoid haemorrhage, when a CT scan indicates no rebleeding, infarction or hydrocephalus?
• Delayed cerebral ischaemia (DCI)
o Cerebral vasospasm
o Local hypoperfusion or disordered
autoregulation
• Non-convulsive seizures
44
What's the rationale for including clindamycin or linezolid alongside broad- spectrum antibiotics in the treatment of necrotising fasciitis?
For the termination of toxin production
45
Besides hypothermia, what are some alternative reasons for the presence of J-waves on an ECG?
Normal variant (early repolarisation)
HABIT:
Hypercalcaemia
Angina – vasospastic
Brain injury including a subarachnoid
haemorrhage
Idiopathic ventricular fibrillation
Type 1 Brugada syndrome
46
When would you consider placing an inferior vena cava (IVC) filter after a pulmonary embolism (PE)?
• If anticoagulation is contraindicated, e.g. the bleeding risk is very high
• If thrombosis has recurred despite adequate anticoagulation
• If temporary cessation of anticoagulation within one month is anticipated, e.g. pregnant patients within one month of the expected date of delivery
IVC filters have no long-term mortality benefit. As foreign material, they are thrombogenic (↑ incidence of DVT).
47
What is the utility of the LRINEC (Laboratory Risk Indicator for Necrotising Fasciitis) score?
• The LRINEC score distinguishes necrotising fasciitis from other soft tissue infections, e.g. cellulitis.
• The score incorporates CRP, WCC, Hb, sodium, creatinine and glucose.
• A LRINEC score of ≥6 could be used as a potential tool to rule in necrotising fasciitis, but a score <6 should not be used to rule out the diagnosis.
• A score ≥8 has a positive predictive value >90%.
48
Is it necessary to check digoxin levels during and after administering digoxin‐specific antibody fragments for digoxin toxicity?
No – the assay measures both digoxin bound to antibody fragments and free digoxin. This overestimates free levels.
49
What fibrinogen level may warrant administering cryoprecipitate in a trauma patient?
Fibrinogen < 1.5–2 g/L
50
What is the normal axis for left ventricular depolarisation in an adult, and what are the Sokolow-Lyon criteria for left ventricular hypertrophy (LVH)?
• Normal axis: −30 to +90 degrees
• LVH: If the height of the R wave in
V5/6 + the depth of the S wave in V1/2 is
≥35 mm
• The most common cause of LVH is
hypertension
51
What are the two pathways of coagulation?
Intrinsic Pathway (APTT): Factors 8, 9, 11, 12
Extrinsic Pathway (PT): Factors 3, 7
Joint: Factors 2, 5, 10, prothrombin, fibrinogen
52
Which substances are primarily responsible for crystal nephropathy in tumour lysis syndrome?
Uric acid and calcium phosphate
↑ Cell turnover →
↑ purine metabolism →
↑ serum urate↑ Cell lysis →
↑ serum phosphate which binds
to calcium
Uric acid precipitates readily in the presence of calcium phosphate, and calcium phosphate precipitates readily in the presence of uric acid.
53
According to the BTS guidelines, when do you insert a chest drain for a spontaneous pneumothorax (PTX)?
1. Primary PTX when aspiration fails. Aspiration is indicated for a primary PTX when breathless and/or size is >2 cm.
2. Secondary PTX when aspiration fails. Aspiration is indicated for a secondary PTX when the size is 1–2 cm.
3. Secondary PTX when the patient is breathless and/or the size of the pneu- mothorax is >2 cm.
54
What clinical feature would indicate a
haemodynamically unstable pulmonary embolism (previously called a massive or high-risk PE)?
Significant hypotension:
Blood pressure of <90 mmHg OR a drop of >40 mmHg from baseline, which is not explained by something else, e.g. arrhythmia, hypovolaemia or sepsis.
55
What makes ketamine effective in enhancing lung function and alleviating bronchospasm in asthma?
It is a bronchodilator.
It is a phencyclidine derivative. It has
little effect on the laryngeal reflexes,
and a patent airway can often be maintained. However, it can induce ↑ secretion production, potentially leading to laryngospasm due to these retained reflexes.
56
What CT features are associated with an increased severity of acute pancreatitis?
• Extensive fat stranding
• Peri-pancreatitis fluid collections
• Pancreatic necrosis
57
On which side of the body do traumatic diaphragmatic injuries tend to occur?
Left
58
What are the principles of ventilating someone with life‐threatening asthma and which strategies can achieve this?
Principles:
Lung protective ventilation:
• Limit peak and
mean airway
pressures
• Allow for a prolonged
expiratory time
• Maintain adequate
oxygenation
Strategies:
• ↓ Tidal volume
• ↓RR
• ↓ Or removal of
extrinsic PEEP
• ↓ Inspiratory time or
↑ expiratory time
• Permissive
hypercapnia
• Intermittent
disconnection from ventilator and manual chest decompression
59
Why should care be taken when giving flumazenil?
It reverses the effects of benzodiazepines.
It has a relatively short half-life when compared to benzodiazepines and has a risk of provoking seizures when administered.
60
What do the Berlin criteria for ARDS entail?
Berlin criteria:
Timing:
Within one week of a known clinical insult or new/worsening respiratory symptoms
Oxygenation (P/F ratios):
PaO2/FiO2 < 40 kPa (≤300 mmHg) with a minimum PEEP of
5 cm H2O
• Mild ≤ 39.9 kPa
• Moderate ≤ 26.6 kPa
• Severe ≤ 13.3 kPa
CXR or CT:
Bilateral opacities not explained by effusions/collapse/nodules
Origin of oedema:
Respiratory failure NOT fully explained by cardiac failure or fluid overload
61
What are the four key recommendations of the New Global Definition of ARDS that expand upon the Berlin Criteria?
• Intubation is not required for making
a diagnosis. This includes patients on high-flow nasal oxygen (HFNO) ≥ 30 L/min or NIV/CPAP with end-expiratory pressure ≥ 5 cmH2O.
• Uses SpO2/FiO2 as an alternative to P/F to assess oxygenation. A SpO2/ FiO2 ≤ 315 + SpO2 ≤ 97% is indicative of compromised oxygenation.
• The requirement of bilateral lung opacities as an imaging criterion remains, but now includes using ultrasound, provided it is performed by a well-trained operator.
• In settings with limited resources, the following are not essential for diagnosis: PEEP, specific oxygen flow rates, or particular types of respiratory support devices.
62
Which ion has the most significant impact on the resting potential of neural tissue?
Potassium – This has a large concentration gradient across the cell membrane and the greatest permeability at rest.
Every cell membrane has a transmembrane potential difference of –70 mV. This difference is dependent on two factors: The transmembrane concentration gradient and the permeability of the membrane to the ions.
63
What are some general respiratory changes that occur by the third trimester of pregnancy?
Increases:
TV, RR, pH, PaO2, Maternal 2,3-DPG
Decreases:
Chest wall compliance, airway resistance, FRC, Bicarb, PaCO2
Lung compliance stays the same
64
What is the pathogenesis of hepatic encephalopathy (HE) in chronic liver disease and what are some treatment options?
• Pathogenesis:
HE occurs when the
liver cannot remove ammonia from enteric sources. This ammonia enters the systemic circulation. It goes to the brain to cause neurotoxicity and cerebral oedema.
• Management:
Treat any precipitating factor, e.g.
SBP, UGIB, electrolyte disturbances. May also need organ support on ICU, e.g. for ↓ GCS in Grade 4 HE
Lactulose & Rifaximin: ↓ Ammonia levels in the gut by ↑ transit time and ↓ bacterial numbers
LOLA: Removes ammonia from the blood through extrahepatic metabolism of ammonia to glutamine. This treatment is not widely available and has little evidence of benefit.
65
Which parameters on a blood gas are directly and indirectly measured?
• Direct: pH, PaO2, PaCO2
• Indirect: Standard bicarbonate, base
excess, SaO2
66
How do you treat prilocaine toxicity?
Methylthioninium chloride (methylene blue) 1 mg/kg IV
• Prilocaine is metabolised in the liver to O-toluidine.
• O-toluidine oxidises haemoglobin into methaemoglobin.
• Methaemoglobin has ↓ oxygen-carrying capacity resulting in cyanosis.
• Methylene blue accelerates the reduction of methaemoglobin.
67
How do you distinguish between
hyperacute, acute and subacute liver failure using the O’Grady classification?
Acute liver failure is triad of jaundice, coagulopathy and encephalopathy. It is classified according to the time from the onset of jaundice to the development of encephalopathy:
• Hyperacute disease: <7 days
• Acute disease: 1–4 weeks
• Subacute disease: 4–12 weeks
68
What is meant by pulsus paradoxus and in which clinical contexts may it be present?
An amplification of the typical drop in systolic BP during inhalation by >10 mmHg. When severe, the radial pulse vanishes during inspiration.
The ‘paradox’ is that the pulse disappears despite cardiac contraction. It is often due to pericardial disease, particularly cardiac tamponade, but can occur in many contexts including (‘PRACTICE’):
• Pulmonary embolism
• RV infarction and Restrictive
cardiomyopathy
• Asthma and COPD (severe)
• Cardiac tamponade and Constrictive
pericarditis
• Tension pneumothorax
• Iatrogenic during surgery
• Compression (obesity, pectus
excavatum)
• Effusions (large bilateral pleural effusions)
69
What ECG pattern has developed if a person who took a large quantity of cocaine now has ST elevation in V 1-3 and T wave inversion in V 1-2?
Drug induced Brugada
70
What type of lung injury does a titrated PEEP strategy aim to decrease when treating ARDS?
Atelectotrauma
71
What are the King’s criteria for non‐ paracetamol‐induced acute liver failure?
INR > 6.5
(PT > 100 seconds)
OR
Any three of the following:
• Aetiology: Non-A, non-B hepatitis or idiosyncratic drug reaction
• Bilirubin > 300 μmol/L
• Age < 11 or > 40 years
• INR > 3.5 (PT > 50 seconds)
• Time from onset
of jaundice to encephalopathy > 7 days
72
Which three clinical signs make up Beck’s triad in acute pericardial tamponade?
• ↓BP
• ↓ Heart sounds (quiet/muffled)
• ↑ CVP – distended neck veins
73
How does mannitol reduce intracranial pressure (ICP)?
Mannitol is a diuretic and 'free radical scavenger'. It is freely filtered through the glomerulus and is not re-absorbed. It decreases ICP in two main ways:
Immediate (Plasma Expansion):
Plasma expansion results in:↓ Blood viscosity↑ Intravascular volume ↑ Cardiac output
Overall, these effects result in ↑ regional cerebral blood flow and compensatory cerebral vasoconstriction in brain regions where autoregulation is intact
Delayed (Osmotic):
↑ Plasma osmolality → shifts water from cerebral extracellular space into plasma → ↓ cerebral oedema (if the BBB is intact)
74
Which arrhythmias can cause cannon‐A waves in the JVP waveform?
• Complete heart block
• Ventricular tachycardia
• Junctional rhythms including AVNRT
75
Which complication of heparin therapy carries the highest mortality?
Type 2 HIT (heparin-induced thrombocytopaenia) due to arterial/venous thrombotic complications
Type 2 HIT: Onset time 5-14 days (compared to 1-4 in type 1), causes arterio/venous thrombosis, need to stop heparin and start alternative anticoagulant
76
How may somatosensory evoked potentials (SSEPs) suggest poor neurological outcome post-cardiac arrest?
They test the somatosensory pathway integrity.
Stimulating a peripheral nerve, e.g. median nerve can be detected at the cortical level. The bilateral absence of the N20 spike on SSEP testing can be used as part of neuro-prognostication in predicting
poor neurological outcome in comatosed patients following cardiac arrest.
77
What is the classical CSF finding in Guillain– Barré syndrome (GBS)?
Albuminocytological dissociation
(↑ CSF protein, normal glucose and no pleocytosis)
GBS is a post-infectious immune-mediated acute inflammatory demyelinating polyneuropathy (AIDP). The majority of cases occur within one month of a respiratory
or GI infection, e.g. Campylobacter
jejuni, Mycoplasma pneumoniae, CMV or EBV. The pathogenesis is a cross reaction
of antibodies with gangliosides in the peripheral nervous system. Anti-ganglioside antibodies (e.g. anti-GM1) are present in 25% of patients. The majority of cases exhibit Landry's ascending paralysis, areflexia and autonomic dysfunction. Sensory symptoms tend to be mild/absent.
78
Which reversal agent can you use to manage major bleeding in someone who takes dabigatran?
Idarucizumab–5 mg IV bolus
This is humanised monoclonal antibody fragment that binds to dabigatran and its metabolites.
HD or HF can also remove dabigatran.
79
What are the RIFLE criteria for acute kidney injury?
Risk:↑ Cr × 1.5, >25% ↓in Egfr, UOut
<0.5 mL/kg/hr for 6 hrs
Injury:↑ Cr × 2, >50% ↓in Egfr, Uout
<0.5 mL/kg/hr for 12 hrs
Failure:↑ Cr × 3, Uout <0.3 mL/kg/hr for 24 hrs OR Anuria for 12 hrs
Loss: Loss of renal function > Four weeks
End stage: Loss of renal function > Three months
80
Why is atropine ineffective for treating bradycardia in a heart transplant?
The heart is completely denervated. Therefore, the lack of a vagal input would prevent any anticholinergic effects of atropine. Sympathomimetic agents are used instead for chronotropy or inotropy.
81
Which organism is most likely to cause right- sided infective endocarditis in an intravenous drug user?
Staphylococcus aureus
82
How may hyperoxia cause harm in an acute myocardial infarction?
• Through free radical production
• Through coronary vasoconstriction
83
What are the four mechanisms of AKI in rhabdomyolysis?
1. Myoglobin combines with Tamm–Horsfall protein to form insoluble casts and tubular obstruction.
2. Hyperuricaemia worsens this tubular obstruction.
3. The haem moiety is directly nephrotoxic.
4. There is inappropriate renal vasocon-striction because of hypovolaemia and third-spacing.
84
Why may peripheral oedema develop in cor pulmonale if there is preserved ventricular function?
Chronic hypoxia causes sympathetic stimulation. This activates the renin– angiotensin–aldosterone system (RAAS) which results in fluid retention.
85
What is meant by FVC, FEV1/FVC ratio, TLC and DLCO?
• FVC: Volume from maximal inspiration to maximal expiration
• FEV1/FVC ratio: The portion of FVC exhaled in the first second
• TLC: The total volume of gas in the lungs at maximal inspiration
• DLCO: Lung diffusion capacity for
carbon monoxide, approximating oxygen transfer from alveoli to red blood cells
86
Which laxative class is least likely to cause diarrhoea?
Bulk-forming laxatives, e.g. psyllium, methylcellulose
These laxatives work by absorbing water in the intestine, which increases stool bulk and stimulates peristalsis.
87
What is meant by pre‐excitation in electrophysiology?
There is an accessory pathway between the atria and ventricles. This prematurely activates the ventricles.
88
How do you calculate static compliance?
Cstatic = Vt / (Pplat - PEEP)
89
What are the two types of amiodarone‐ induced thyrotoxicosis (AIT)?
Pre‐existing thyroid disease?:
T1 - Often, T2 - No
Pathology:
T1 - Excessive hormone synthesis due to excess iodine found in amiodarone
T2 - Excessive release of preformed hormones due to thyroiditis
Goitre:
T1 - Mostly multinodular
T2 - Absent or small
Radioiodine isotope uptake:
T1 - Normal, T2 -↓/ absent
Thyroid ABS:
T1 - Present, T2 - Absent
IL‐6:
T1 - Normal/mildly raised, T2 - Very high
Treatment options:
T1:
• Stop amiodarone
• Antithyroid drugs
• K+ perchlorate
• Thyroidectomy
T2:
• Stop amiodarone
• Anti- inflammatory drugs, e.g. prednisolone
90
When should you send blood for mast cell tryptase in anaphylaxis?
• Initial sample as soon as possible
• Second sample at 1–2 hours
• Third sample at 24 hours or in
convalescence
91
Why may Torsades de Pointes (TdP) develop after giving amiodarone to treat atrial fibrillation?
Amiodarone prolongs the QT interval. QT prolongation increases the risk of TdP
92
What are the five different types of myocardial infarction (MI)?
Type 1:
Acute coronary syndrome
Caused by coronary artery disease with atherothrombotic plaque rupture or erosion leading to either an occlusive or partially occlusive thrombus
Type 2:
Supply– demand imbalance
Myocardial cell death secondary to an oxygen supply–demand imbalance to the myocardium, e.g. septic shock, hypoxia or hypovolaemia
Type 3:
MI causing death
Symptoms indicative of MI with presumed new ECG changes or ventricular fibrillation, but biomarker samples not obtained before death
MI detected at autopsy
examination
Type 4:
PCI‐related
Type 4a: Procedure-related MI occurring 48 hours after PCI
Type 4b: MI due to stent or scaffold thrombosis following PCI
Type 4c: Restenosis associated with PCI
Type 5:
CABG‐ related
Procedural myocardial injury during or ≤ 48 hours after CABG/cardiac surgery
93
What is normal pleural fluid pH and what pH would you expect in a parapneumonic effusion?
Normal: 7.6 - 7.66
Uncomplicated parapneumonic effusion: >7.2
Complicated parapneumonic effusion: <7.2
Empyema: Tis Pus
94
How would you manage someone with longstanding atrial fibrillation with adverse signs if their INR was 1.3?
Sedation + synchronised DC cardioversion
The risk of embolisation (~6.8%) is outweighed by the need for urgent HR control.
There is no difference in the incidence of embolic phenomena between chemical or electrical; electrical cardioversion occurs faster.
95
What are the grades of hepatic encephalopathy (HE)?
1:
Mild confusion,↓ Attention, Mild asterixis/ tremor
2:
Lethargy, Disorientation, inappropriate behaviour, Asterixis, slurred speech
3:
Somnolent but rousable, Bizarre behaviour, Rigidity, clonus, hyperreflexia
4:
Coma, Abnormal posturing
96
What are some causes of an overdamped A-line trace?
• Tubing: Overly compliant, narrow or kinked
• Obstruction: Air bubbles, blood clots
• Pressure bag: Underinflated or low flush
bag pressure
• Connections: Loose connections in
the fluid-filled part of the electronic
monitoring system
• Artery: Arterial spasm
97
What kind of inspiratory pattern does volume‐controlled ventilation produce?
Square inspiratory flow pattern
98
What makes noradrenaline a suitable option to manage hypotension following elective surgery in someone with known severe aortic stenosis (AS) with a peak transvalvular gradient of 80 mmHg?
Noradrenaline → ↑ SVR → ↑ DBP → ↑ coronary perfusion
In severe AS, maintaining good coronary perfusion is essential as the LV is hypertrophied and prone to ischaemia if the DBP falls.
Drugs that ↓ afterload or ↑ heart rate (↓ diastolic time) should be avoided.
99
How do you diagnose peritoneal dialysis (PD) peritonitis and which organisms are implicated?
Two of the following:
• The presence of signs/symptoms such as fever, abdominal pain, nausea, vomiting or cloudy effluent
• A white cell count >100 per mL of effluent with >50% neutrophils after a 2-hour dwell
• A positive culture from the effluent
The most common organisms are coagulase-negative Staphylococcus, non- Pseudomonas Gram-negative organisms and Staphylococcus aureus. Treatment should include intra-peritoneal antibiotics.
100
What are the absolute contraindications to full face mask NIV in an acute exacerbation of COPD?
• Patient refusal
• Severe facial deformity
• Facial burns
• Fixed upper airway obstruction
• Pneumothorax (unless a chest drain is inserted)
• Recent upper GI surgery
101
Which Mapleson circuits are best suited for neonates?
Mapleson E and F
102
Which pathophysiological mechanism would increase peak airway pressure but not plateau pressure?
↑ Airway resistance
103
Which drugs are recommended to treat cocaine‐associated hypertension, and why are beta-blockers not recommended first-line?
• Benzodiazepines (e.g. diazepam)
• Nitrates (e.g. glyceryl trinitrate)
• Alpha-blockers (e.g. phentolamine)
Cocaine is an indirectly acting sympathomimetic. It causes hypertension due to ↓ reuptake of noradrenaline at sympathetic nerve terminals.
Beta blockade results in unopposed alpha stimulation. This can worsen coronary artery vasoconstriction and systemic hypertension.
104
Which triggers are used to support a patient‐ initiated breath on a ventilator?
• Flow: A pre-set flow rate generated by the patient triggers a supported breath.
• Pressure: A ↓ in pressure below a pre-set value within the ventilator circuit triggers a supported breath.
105
Which anion and cation are the most prevalent intracellularly?
• Anion: Phosphate
• Cation: Potassium
106
How do you define a sub‐massive pulmonary embolism (PE) (intermediate-risk PE)?
PE + RV dysfunction/myocardial necrosis without systemic hypotension/ haemodynamic instability
• RV dysfunction: dilated RV on CT/TTE, new RBBB, S1Q3T3, ↑ BNP
• Myocardial necrosis: ↑ Cardiac enzymes, e.g. Troponin
107
Which chromosome contains the predisposing gene for malignant hyperthermia (MH) and what is MH?
Chromosome 19 – close to the gene for the ryanodine/dihydropyridine receptor complex
• During anaesthesia, abnormal skeletal muscle contraction and metabolism lead to ↑ temperature and ↑ muscle rigidity.
• Triggers are volatile agents and suxamethonium.
• A rapid ↑ in ETCO2 is one of the earliest signs. Other features may include CVS instability and cyanosis. The reaction can be delayed for several hours.
• Muscle biopsies may appear histologically normal, and the caffeine halothane contracture test is the gold standard for diagnosis.
• Treatment is with IV dantrolene.
108
What is central cord syndrome and what are its main clinical features?
Bleeding, infarction or oedema involving the central grey matter of the spinal cord.
Features:
Motor loss in upper limbs > motor loss
Upper limbs:
Mixed UMN and LMN signs
Loss of pain and temperature
Lower limbs:
UMN signs
Variable sensory changes
109
In an adult, where should the balloon tip of an intra‐aortic balloon pump (IABP) be situated when it’s properly positioned?
In the descending thoracic aorta approximately 2 cm distal to the origin of the left subclavian artery
110
What bispectral index (BIS) should be targeted for a change of dressing in someone with an extensive burn?
40 − 60 (for GA and amnesia)
BIS values range from 0 to 100.
0 is no brain activity and 100 is wide awake.
111
What accounts for alfentanil’s faster onset of action in comparison to fentanyl, even though alfentanil has a lower lipid solubility than fentanyl?
Alfentanil's faster onset of action is attributed
to its lower pKa value (6.5) compared to fentanyl's pKa of 8.4. At physiological pH, this lower pKa means that more alfentanil exists in a non-ionised form. Non-ionised drugs are more lipophilic and can cross the blood-brain barrier more easily, leading to a faster onset of action.
112
What is the most likely diagnosis if a lady presents with breathlessness, a raised JVP, a cough with clear sputum and bilateral infiltrates on her chest X-ray 10 days after a C-section?
Postpartum cardiomyopathy
Presentation and treatment are similar to congestive cardiac failure. An echo will often show diastolic dysfunction. It can present up to five months post-delivery.
113
What is the effect of constipation on the efficiency of peritoneal dialysis (PD)?
Constipation will ↓ the efficiency of PD.
• A Tenckhoff catheter delivers dialysate into the peritoneum, where it stays to remove waste and fluid before being drained.
• The characteristics of the dialysate and the duration it stays in the peritoneum can be modified to affect clearance and salt/ water balance.
• Constipation affects the efficiency of PD as it ↓ dialysate flow.
114
What is the effect of constipation on the efficiency of peritoneal dialysis (PD)?
Constipation will ↓ the efficiency of PD.
• A Tenckhoff catheter delivers dialysate into the peritoneum, where it stays to remove waste and fluid before being drained.
• The characteristics of the dialysate and the duration it stays in the peritoneum can be modified to affect clearance and salt/ water balance.
• Constipation affects the efficiency of PD as it ↓ dialysate flow.
115
Where does the fresh gas flow (FGF) enter a Mapleson C or Water’s circuit?
Between the reservoir bag (RB) and the adjustable pressure limiting (APL) valve:
It needs 15 L/min O2 to prevent rebreathing. The APL valve controls pressures and PEEP (up to ~ 60 cmH2O).
116
Which muscle can be coinfected in pyelonephritis?
• Psoas muscle – an abscess can form – because the kidneys are retroperitoneal.
• A psoas abscess is best imaged with an MRI.
117
What is the best way to confirm placement of endotracheal tube immediately after intubation?
Continuous waveform end-tidal capnography
118
What is the best treatment to manage someone who developed a LV aneurysm and LVEF 22% following a STEMI and has just received amiodarone for an episode of VT?
ICD implantation
A ↓ ejection fraction and LV aneurysm ↑ the risk of recurrent VT and sudden cardiac death.
Aneurysm excision is reserved as a last line for those with recurrent VT despite other interventions.
119
What are the initial BiPAP settings for an acute exacerbation of COPD?
• Indication: Respiratory acidosis (pH
< 7.35, PaCO2 > 6 kPa) after 1 hour of medical treatment
• IPAP: 10
• EPAP: 4–5
• Target SpO2: 88–92%
The IPAP is gradually increased until therapeutic response and/or patient tolerability.
120
Is there evidence for implanting left ventricular assist devices (LVADs) in patients with end-stage heart failure?
Yes
REMATCH trial (2001) compared permanent LVAD insertion with best medical management in those not eligible for transplant. It demonstrated a ↓ one-year and two-year all-cause mortality with permanent LVAD insertion.
121
What are the primary functions of an intra‐ aortic balloon pump (IABP) and what does the balloon contain?
Primary functions:
↑ Myocardial oxygen supply
↑ LV ejection fraction and cardiac output ↓ Myocardial oxygen demand
↓ LV afterload
↓ LV wall stress
Balloon:
• Filled with helium which has ↓ viscosity. This allows it to travel quickly through the connecting tubes.
• Compared to air, there is a ↓ risk of air embolism if ruptured.
• When inflated, the balloon should
partially occlude the descending aorta (not >80–90% of its diameter).
122
Which Lindegaard ratio is suggestive of vasospasm on transcranial Doppler studies in someone with a subarachnoid haemorrhage (SAH)?
A ratio > 3 is suggestive of vasospasm.
The Lindegaard ratio is the ratio of flow velocity in the ipsilateral middle cerebral and internal carotid artery:
Mean flow velocity in/ MCA Mean flow velocity in ICA
It helps to distinguish hyperaemia from vasospasm. It is based on the principle that as an artery narrows, the blood flow velocity within it increases:
• <3 suggests alternative aetiology, e.g. hyperaemia
• >3 suggests mild to moderate vasospasm
• >6 suggests severe vasospasm
Vasospasm is a narrowing of the intracranial arteries and can occur following a SAH. Incidence peaks at 3–10 days post-SAH, persists for several days and is associated with a worse outcome.
123
In a post-operative patient with ongoing bleeding and a prolonged R‐time, which blood product would you give?
FFP
The R (reaction)-time reflects the concentration of soluble clotting factors in the plasma. An ↑ R-time suggests a deficiency in clotting factors.
124
Why does excessive tube length lead to an underdamped trace on invasive BP monitoring?
It lowers the natural frequency in the system.
125
Which transplacental autoantibodies are associated with congenital complete heart block in a mother who has systemic lupus erythematosus during pregnancy?
Anti-Ro (SSA) antibodies
126
What are the possible routes by which temporary pacing can be delivered?
Transcutaneous, transvenous, epicardial, oesophageal
127
What pathophysiological mechanism causes an increase in the plateau pressure?
↓ Lung compliance
128
What are the types of patient evacuation in the event of a fire?
Horizontal evacuation: To an adjacent area
Vertical evacuation: To a lower floor
External evacuation: Outside of the building
129
What are the key features of a scleroderma renal crisis (SRC) and how do you treat it?
Renal failure
Accelerated hypertension Microangiopathic haemolytic anaemia
SRC complicates systemic sclerosis in 10% of patients. It is a life-threatening complication characterised by endothelial dysfunction and RAAS activation. As RAAS activation plays a central role in this condition, treatment is with ACE inhibitors.
130
What is the mechanism of action of the primary class of antibiotics frequently employed as first-line treatment in an 18-year-old patient with a headache, photophobia, fever and confusion?
Inhibition of cell wall synthesis
First-line antibiotics for possible bacterial meningitis are cephalosporins.
Penicillins, cephalosporins, carbapenems and monobactams all act via inhibition of cell wall synthesis.
