ACC Flashcards
What 2 criteria are required to diagnose septic shock?
1) MAP <65 mmHg despite fluid resus
2) Lactate >2 mmol/L
What BEDSIDE score can be used to identify patients with suspected infection who are at greater risk for a poor outcome outside of ICU?
qSOFA
What makes up the qSOFA score? (3)
1) RR >22
2) Systolic BP <100 mmHg
3) altered mental state
What qSOFA score indicates someone at a heightened risk of mortality (10% risk)?
≥2
What is the mean arterial pressure? (MAP?
The average pressure in a patient’s arteries during one cardiac cycle.
It is considered a better indicator of perfusion to vital organs than systolic BP.
How does sepsis cause hypoperfusion of organs?
Cytokines released due to inflammation increase the permeability of blood vessels.
This causes oedema and reduced intravascular volume.
Oedema creates a gap between the blood and the tissues, reducing the amount of oxygen that reaches the tissues.
What is released in sepsis that results in vasodilation?
Nitrous oxide
In order to generate a palpable femoral pulse, what arterial pressure is required?
> 65 mmHg
Which general anaesthetic has a side effect of pain on injection?
Propofol
2 key adverse effects of propofol?
1) Pain on injection site
2) Marked drop in BP
Which general anaesthetic has a side effect of laryngospasm?
Thiopental sodium
Which general anaesthetic has a side effect of 1ary adrenal suppression?
Etomidate
2 main side effects of etomidate?
1) 1ary adrenal suppression
2) Myoclonus
How does etomidate cause adrenal suppression?
As reversibly inhibits 11b-hydroxylase
What 2 things is malignant hyperthermia triggered by?
1) Suxamethonium
2) Volatile anaesthetics
Definitive diagnosis of malignant hyperthermia?
Genetic testing afterwards
Which general anaesthetic is post-op vomiting common in?
Etomidate
Mechanism of IV dantrolene in malignant hyperthermia?
Ryanodine receptor antagonist –> helps to decrease intracellular calcium concentration and muscle metabolism
What is the most common cause of malignant hyperthermia?
Autosomal dominant mutation in ryanodine receptor.
This results in an abnormality in calcium regulation within muscle cells –> leads to increased calcium levels in the sarcoplasmic reticulum and a consequent increase in metabolic rate.
Which general anaesthetic may cause marked myocardial depression?
Thiopental sodium
Inheritance of mutation in malignant hyperthermia?
Autosomal dominant
What does a simple general anaesthetic induction ‘recipe’ for tracheal intubation in a fit and well patient usually incorporate?
Quick acting opiate e.g. fentanyl + propofol
How many test breaths are delivered whilst confirming tube placement within the trachea?
5
How is tube placement confirmed within the trachea? (3)
1) 5 waves on capnography
2) Symmetrical chest expansion
3) Misting of tube
What intraoperative monitoring is required?
(3)
1) Obs: HR, BP, O2 & capnography
2) Depth of anaesthesia: BIS monitor or MAC
3) Neuromuscular blockade w/ peripheral nerve stimulator
What does a BIS monitor analyse?
EEG (brain activity)
What medication is used specifically to reverse the effects of certain non-depolarising muscle relaxants (rocuronium and vecuronium)?
Sugammadex
What is the NMDA receptor?
A receptor of glutamate (the primary excitatory neurotransmitter).
How can the degree of the neuromuscular blockade be assessed?
Peripheral nerve stimulator
Where are the leads typically over in a peripheral nerve stimulator?
Facial or ulnar nerve
Mechanism of ketamine?
NMDA receptor antagonist
What class of medication can reverse the effects of neuromuscular blocking medications?
cholinesterase inhibitors e.g. neostigmine
What 2 GA agents do NOT cause marked hypotension?
Ketamine & etomidate
Who cyclizine be used with caution in?
HF & elderly
What inhaled GA has the worst environmental effect?
Desflurane
What is the main contraindication for thiopentone?
Porphyria
Which inhaled GA is used in organ donation?
Isoflurane (due to least effect on organ blood flow)
Which inhalational agent is sweet smelling?
Sevoflurane
What is ‘train of four’ stimulation?
Four consecutive 2 Hz stimuli to a chosen muscle group and the respective number of twitches evoked.
This provides information on the patient’s recovery from neuromuscular blockade.
What are 3 common antiemetics given for prophylaxis given at the end of the operation?
1) Ondansetron
2) Cyclizine
3) Dexamethasone
How do muscle relaxants work?
Block ACh action at NMJ
What is the most common short acting opioid used at time of anaesthesia induction?
Fentanyl
Mechanism of cyclizine?
Antihistamine (H1 receptor antagonist)
What result of train-of-four (TOF) stimulation indicates that muscle relaxants haven’t fully worn off?
Muscle responses get weaker with additional stimulation
What is minimum alveolar concentration (MAC)?
Minimum concentration of inhaled anaesthetic at which 50% of people don’t move in response to a noxious stimuli.
When can MAC be used to measure the depth of anaesthesia?
If VOLATILE agents are used
What is suxamethonium apnoea also known as?
Pseudocholinesterase deficiency
Which inhaled GA is associated with hepatotoxicity?
Halothane
What is the muscle relaxant of choice for RSI for intubation?
Suxamethonium
What drug is often used in epidural anaesthesia?
Levobupivacaine +/- fentanyl
What is the caudal space?
Extension of epidural space (at bottom of spine)
What are anaesthetics used for spinal anaesthesia mixed with?
Why?
Dextrose
To make them hyperbaric (i.e. denser than CSF)
Purpose of local anaesthetics used for spinal anaesthesia being hyperbaric?
1) Greater spread in the direction of gravity
2) More predictable with minimal inter-patient variability
Which nerve block is mostly performed to provide analgesia following rib fractures and thoracic surgery?
Intercostal
What type of peripheral nerve block is used for hand operations?
Axillary
Who is caudal anaesthesia more useful in?
Paediatric patients
What type of peripheral nerve block is used for elbow operations?
Supraclavicular
What is a complication of an intercostal block?
Pneumothorax
What are the 2 key risk factors for lidocaine toxicity?
1) Hypoalbuminaemia (as lidocaine is protein bound)
2) Hepatic dysfunction
Which local anaesthetic has the fastest onset?
Lidocaine
What is the safe dose for Lignocaine with and without adrenaline?
Without –> 3mg/kg
With –> 7mg/kg
Presentation of ipsilateral phrenic nerve palsy?
SOB
Where does the subarachnoid space end?
S1
What is the safe dose for bupivacaine?
2mg/kg
A patient is administered local anaesthetic at the end of an operation.
The surgeon infiltrates 20ml of 2% lidocaine.
How many mg of lidocaine dose this amount to?
1% lidocaine = 1g per 100ml
2% = 2g per 100ml
2g = 2000mg
2000 / 5 (as 100 / 20 = 5) = 400mg
What is wound dehiscence?
A post-operative complication in which a wound ruptures along the surgical incision site.
Superficial –> non-urgent senior review
Deep –> emergency
How should OD insulin be adjusted on the day before and day of surgery?
Generally reduced by 20%
How can suxamethonium affect K+?
Can cause hyperkalaemia
Adrenaline dose in anaphylaxis:
a) IM
b) IV
a) 0.5ml 1:1000
b) 0.5ml 1:10000
Repeat doses every 5 mins
When should you suspect pulmonary oedema following general anaesthetics?
In hypoxic patients following laryngospasm
respiratory sound in bronchospasm vs laryngospasm?
Bronchospasm - wheeze
Laryngospasm - stridor
What 2 things should be ruled out following laryngospasm?
1) Pulmonary oedema
2) Aspiration
What is intraoperative hypothermia defined as?
<36 degrees
What electrolyte abnormality can contribute to post-op ileus?
Hyperkalaemia
How can laryngospasm result in pulmonary oedema?
Inspiratory effort against the closed glottis leads to excessive negative pressure within the alveoli, resulting in pulmonary oedema.
How can perioperative hypothermia cause prolonged recovery from anaesthesia?
Reduction in body temperature can lead to prolongation of anaesthetic drugs, neuromuscular blocking agents and inhalational agents.
What 2 methods are used to monitor temp in anaesthetics?
1) Tympanic thermometer
2) Oesophageal probe
What is laryngospasm?
Partial or complete reflex adduction of vocal cords due to the involuntary contraction of the intrinsic muscle of the larynx.
This may cause a variable degree of upper airway obstruction.
Closure of the glottic opening is a primitive protective airway reflex to prevent aspiration.
At what volume should IV fluids be warmed prior to administration?
> 500 ml
Define the pre-operative phase
Starting 1 hour before induction of anaesthesia
What are the 3 most common sites of insertion for a central line?
1) Internal jugular vein (most common)
2) Subclavian vein
3) Femoral vein
Which LA can cause cardiotoxicity?
Bupivacaine
Why is bupivacaine contraindicated in regional anaesthesia?
Due to cardiotoxicity - in case tourniquet fails
Mx of the following drugs before surgery:
a) ACEi e.g. ramipril
b) sulfonylureas
c) warfarin
d) clopidogrel
a) stop day before
b) stop day of (unless BD and morning surgery - can have afternoon dose)
c) 5 days before (bridge with LMWH)
d) 7 days before
Which type of anaesthetic drug can cause fasciculations?
Depolarising muscle relxanats e.g. Suxamethonium
Which term refers to the volume of air pushed in per breath during mechanical ventilation?
Tidal volume
What abdominal findings may be seen in tricuspid regurgitation? (2)
1) Pulsatile liver
2) Ascites
What is the name for treatment with a triple chamber pacemaker in severe heart failure with an ejection fraction of less than 35%? (1)
CRT
What pH is sufficient to confirm the placement of an NG tube?
<5
What is the recommended volume of maintenance fluids in adults?
25-30 ml/kg/day
How does diarrhoea affect the anion gap?
Does not affect anion gap
Causes normal anion gap metabolic acidosis
Mx of ischaemic stroke?
300mg aspirin daily for 2 weeks
75mg clopidogrel lifelong (or aspirin + dipyridamole if clopidogrel contraindicated)
What is a useful stategy for lowering ICP in cases of conservative management?
Hyperventilation
This results in decreased pCO2 –> vasoconstriction
What medication may be beneficial in the prophylactic treatment of cluster headaches?
Verapamil
Patients with which condition are particularly sensitive to non-depolarising agents (e.g. rocuronium)?
Myasthenia gravis
Which two factors contribute to the mean arterial pressure? (2)
1) Systemic vascular resistance
2) Cardiac output
Why should you avoid using hypotonic (0.45%) saline in paed patients?
Risk of hyponatraemic encephalopathy
Which are the main spinal tracts that carry pain signals through the spinal cord? (2)
1) Spinothalamic
2) Spinoreticular
At what dose of prednisolone do patients require hydrocortisone supplementation during surgery?
10mg or more
What enzyme is deficient in suxamethonium apnoea?
Acetylcholinesterase
What score can be used to predict mortality at time of admission to ICU?
APACHE score
What does inspiratory vs expiratory stridor indicate?
Inspiratory - laryngeal obstruction
Expiratory - tracheobronchial obstruction
Dose of nebulised ipratropium bromide given in acute severe asthma in adults?
0.5mg every 4-6 hours
Dose of prednisolone given in acute severe asthma in adults?
40-50mg
What AMTS score indicates confusion?
≤8, or new disorientation in person, place or time.
Mechanism of LA?
Block sodium channels
What amount of lidocaine dose 1% lidocaine contain?
1% lidocaine = 1g per 100ml
= 1000mg per 100ml
How many mg in a gram?
1000
Why should TPN be administered via a central line?
As it is strongly phlebitic
How much should OD insulin dose be reduced on day before and day or surgery?
Reduce by 20%
What should be used for pharmacological VTE prophylaxis in patients with CKD?
UH
How should DPP-4 inhibtiors (-gliptins) and GLP-1 analogues (-tides) be altered prior to surgery?
Keep taking as normal
Describe ASA grade VI
Declared brain dead - organ removal for donor purposes.
Calculation for serum osmolality?
2xNa + glucose + urea
What 2 diuretics can cause hyponatraemia?
1) thiazide
2) potassium sparing
What is ADH released in response to?
Increased serum osmolality
Who is primary polydipsia seen in?
(4)
1) Psychiatric disturbances
2) MDMA
3) Severe hypothyroidism
4) Glucocorticoid deficiency
The clinical features of hyponatraemia are primarily neurological.
Why?
Due to the effects of cerebral oedema
If the sodium is corrected too quickly in hyponatraemia, what is the patient at risk of?
Osmotic demyelination syndrome
How does osmotic demyelination syndrome typically present?
(2)
1) Quadriplegia
2) Pseudobulbar palsy
Management of hypervolaemic hyponatraemia?
Fluid restriction
Management of hypovolaemic hyponatraemia?
Rehydration with 0.9% saline
Management of SIADH?
Fluid restriction
How can serum glucose affect sodium?
Significant hyperglycaemia can cause hyponatraemia, often with raised serum osmolality.
How can hypothyroidism affect sodium?
Can cause hyponatraemia due to SIADH
How can NMS affect WCC?
Can cause raised WCC (leukocytosis)
What happens in COPD patients that receive too much O2?
Lose their hypoxic drive –> retain CO2 –> hypoventilate –> respiratory distress
Why does hypomagnesaemia need to be corrected before hypokalaemia?
As hypomagnesaemia prevents potassium absorption
What 3 electrolyte abnormalities can thiazide like diuretics cause?
1) hyponatraemia
2) hypokalaemia
3) hypercalcaemia
How can temp affect pancreas?
Hypothermia is a cause of acute pancreatitis
Correcting sodium levels rapidly is dangerous.
What is the risk of:
a) hyponatraemia correction
b) hypernatraemia correction
a) osmotic demyelination syndrome
b) cerebral oedema
Which diabetic drug can cause fluid retention?
Pioglitazone
1st line investigation in typical/atypical angina?
CT coronary angiography
How can acute pancreatitis affect calcium?
Can cause hypocalcaemia
What is the most common organism causng necrotising fasciitis (NF)?
GAS i.e. Strep. pyogenes
Which type of NF causes gas gangrene?
Type III
What classification system is used to guide management of cellulitis?
Eron classification
What is cellulitis an infection of?
Dermis + subcutaneous tissue
What Eron classification indicates admission for IV Abx in cellulitis?
III and IV
2 main organisms causing cellulitis?
GAS & S. aureus
1st line anticoagulation in DVT if patient has antiphospholipid syndrome?
LMWH
What pupillary defect may be seen in orbital cellulitis?
RAPD (indicates optic nerve involvement)
Abx of choice in cellulitis in penicillin allergic patients?
Erythromycin
Next step in DVT if proximal US scan is negative but d-dimer is positive?
Stop anticoagulation, repeat US scan in 1 week
Mx of a cyanide OD?
Hydroxocobalamin
Dose of morphine given in ACS?
1-10mg
Titrate according to patient’s pain level.
What structure connects the 3rd & 4th ventricle?
Cerebral aqueduct
What is the most common cancer to spread to the brain?
Lung
Most malignant tyoe of a glioma?
Glioblastoma multiforme
What are glial cells?
These cells surround and support the neurones
Give 3 examples of glial cells?
1) Astrocytomas
2) Ependymal cells
3) Oligodendrocytes
Which cells regulate the circulation of CSF?
Ependymal cells
Where do ependymomas typically form?
4th ventricle
What layer do meningiomas arise from?
Arachnoid mater
What is the most common 1ary brain tumour in children?
Pilocytic astrocytoma
Most common location of brain tumours in adults vs paeds?
Adults: supratentorial
Paeds: infratentorial
Key histological feature of pilocytic astrocytoma?
Rosenthal fibres (corkscrew eosinophilic bundle)
What is the most common type of brain tumours?
Brain mets
Prognosis of a glioblastoma?
Around 1 year
What type of tumour is a glioblastoma?
Astrocytoma
Role of acetazolamide in idiopathic intracranial HTN?
Carbonic anhydrase inhibitor –> reduces CSF production –> reduces ICP
What may an ependymoma cause?
Hydrocephalus
Where are oligodendromas typically found?
Frontal lobes
What is the most aggressive paediatric tumour?
Medulloblastoma
How does a medulloblastoma spread?
Via CSF
What 2 medications can be used in pituitary tumours causing hormonal excess?
1) Bromocriptine (dopamine agonist)
2) Somatostatin analogue e.g. ocreotide
Give an example of a carbonic anhydrase inhibitor
Acetazolamide
What condition are haemangioblastomas associated with?
Von Hippel-Lindau syndrome
1st line pharmacological therapy for IIH?
Acetazolamide (carbonic anhydrase inhibitor)
What Abx are associated with idiopathic intracranial HTN?
Tetracyclines
What blood test can be done to confirm an anaphylactic reaction afterwards?
Serum tryptase within 6 hours
What antihistamines can be given in anaphylaxis?
Non-sedating antihistamines e.g. cetirizine (i.e. NOT chlorphenamine)
name a non-sedating antihistamine
cetirizine
name a sedating antihistamine
chlorphenamine
When can discharge be considered in anaphylaxis in those:
1) needing 1 dose of IM adrenaline
2) needing 2 doses of IM adrenaline
3) have previously had a biphasic reaction
4) also have severe asthma
5) present late at night
1) 2 hours after symptom resolution
2) 6 hours after symptom resolution
3) 6 hours after symptom resolution
4) 12 hours after symptom resolution
5) 12 hours after symptom resolution
Define refractory anaphylaxis
Not responded to 2x IM doses of adrenaline 5 mins apart.
Injection site for IM adrenaline in anaphylaxis?
Anterolateral aspect of middle third of thigh
IM adrenaline in paeds (6m to 6y)?
IM adrenaline 150mcg (0.15ml 1:1000)
IM adrenaline dose in anaphylaxis:
a) 6m to 6y
b) 6y to 11y
c) adults
a) 0.15ml 1:1000
b) 0.30ml 1:1000
c) 0.5ml 1:1000
What is the underlying cause of vision loss in temporal arteritis?
How does this look on fundoscopy?
Anterior ischaemic optic neuropathy –> caused by inflammation in the posterior ciliary artery (a branch of the ophthalmic artery) which leads to occlusion and subsequent ischaemia to the head of the optic nerve.
This leads to a swollen and pale optic disc with blurred margins.
What is Takayasu’s arteritis?
A large vessel arteritis affecting younger females (10-40y).
It typically causes occlusion of the aorta and questions commonly refer to an absent limb pulse.
Why may a biopsy be normal in temporal arteritis?
due to skip lesions
continue steroids even if biopsy is negative
Features of optic neuritis?
- unilateral decrease in visual acuity over hours or days
- poor discrimination of colours, ‘red desaturation’
- pain worse on eye movement
- relative afferent pupillary defect
- central scotoma
What investigation is diagnostic in most cases of optic neuritis?
MRI of the brain and orbits with gadolinium contrast
Mx of optic neuritis?
High dose steroids
mx of temporal arteritis:
a) vision affected
b) vision not affected
a) oral pred
b) IV methylprednisolone
‘Double sickening’ is associated with bacterial sinusitis.
What is this?
An initial period of recovery followed by a sudden worsening of symptoms.
It is thought to be caused by a 2ary bacterial infection following a viral rhinosinusitis.
What is the most common extra-renal manifestation of ADPKD?
Liver cysts (can cause hepatomegaly)
What cancer can PBC predispose to?
Cholangiocarcinoma
1 unit of blood should increase a patient’s Hb by how much?
10 g/L
What is anaphylaxis caused by a blood transfusion thought to be the result of?
Can be caused by patients with IgA deficiency as they have anti-IgA antibodies.
IgA is found in most blood products.
What are the 2 main electrolyte abnormalities that can occur in blood transfusions?
1) Hypocalcaemia
2) Hyperkalaemia
What is irradiated blood depleted of?
T lymphocytes
What blood products should patients with IgA deficiency receive?
Washed blood products (IgA immunoglobulins have been removed)
What does the ABO blood system refer to?
Type of glycoproteins found on surface of RBCs
How may urine appear in acute haemolytic transfusion reaction?
Red (due to haemoglobinuria)
How can febrile nonhaemolytic transfusion reaction be avoided?
Leukoreduction (WBCs are removed from blood prior to transfusion)
What is the number 1 cause of death among all transfusion reactions?
TRALI
What can be given intraoperatively to reduce risk of PONV?
Dexamethasone
Mechanism of haloperidol?
D2 receptor antagonist
How soon before surgery can a baby breastfeed?
4 hours before
1st line for manipulation in adults & children?
Adults –> benzos
Children –> ketamine
What is next step in getting in an ET if 1st attempt unsuccessful?
Bougie
NG tube aspirate pH to be in the right place?
≤5
How to increase CO2 clearance on BIPAP?
1) Increase RR
2) Increase tidal volume (total volume of each breath) i.e. T insp
How to increase O2 delivery on BiPAP?
Increase PEEP and FiO2
Mx of HAP vs severe HAP?
Co-amoxiclav
Severe - tazocin
What investigations may be indicated in a PE?
1) ECG - sinus tachy, S1Q3T3
2) ABG - hypoxia, respiratory alkalosis (also required as most likely been put on O2)
3) Bloods - FBC, U&Es, coag, d-dimer, consider troponin/BNP
4) CXR - exclude alternative diagnosis
5) CTPA - imaging of choice
6) V/Q scan - in certain circumstances (e.g. pregnancy, renal impairment)
7) Echo - right heart strain
What is the Wells score?
Clinical probability of DVT
What is the PERC score?
A ‘rule out’ score for PE/DVT in low-risk patients
What is the PESI score?
Risk stratification to determine severity in patients with suspected/confirmed PE
What investigation is key before CTPA?
U&Es - look for any renal impairment
Why is coag blood test necessary in PE?
As likely to be put on anticoagulation
What score can be used to determine the severity of a PE?
PESI score (low = possible outpatient mx)
What anticoag should be used in PE in patients with CKD stage 5?
Warfarin
Is UH or LMWH indicated in renal failure?
UH
3 options for hyperacute mx of ischaemic stroke?
1) Thrombectomy - if presenting <6h, then aspirin 300mg 24h later
2) Thrombolysis - if presenting <4.5h, then aspirin 300mg 24h later
3) Aspirin 300mg alone (i.e. if not suitable for thrombectomy or thrombolysis)
Where must the clot be in an ischaemic stroke to qualify for thrombectomy?
There has been a LARGE vessel occlusion i.e. middle cerebral artery (most commonly)
When do patients with ischaemic stroke who have received thrombectomy or thrombolysis receive aspirin 300mg?
24h after (then continue for 2 weeks)
VTE prophylaxis following ischaemic stroke?
Intermittent pneumatic compression (IPCs) for the first 2 weeks.
LMWH VTE prophylaxis thereafter.
Why should LMWH VTE prophylaxis not be used for the first 2 weeks following ischaemic/haemorrhagic stroke?
As they are at increased risk of bleeding into that area in the brain.
A pneumothorax with a lung margin that is >2cm from the chest wall on CXR represents what % lung volume?
This represents a pneumothorax of 50% lung volume
Mx of CAP in patients with CURB-65 0-1?
Treat at home
Oral amoxicillin
What is an alterantive to oral amoxicillin in the mx of CAP?
Doxycycline or clarithromycin
Mx of CAP in patients with CURB-65 2?
Hospital
Oral amoxicillin
Mx of CAP in patients with CURB-65 3-4?
Hospital (consider HDU/ICU)
IV co-amoxiclav
