Day 1 Flashcards
A 26-year-old male has attended the pre-operative assessment clinic before undergoing a tonsillectomy for recurrent tonsillitis.
The anaesthetist elicits a family history from the patient, which reveals that his father and paternal grandfather both experienced malignant hyperthermia following the administration of a general anaesthetic.
His mother and his paternal grandmother have never had an adverse reaction following a general anaesthetic.
What is the chance of this patient having the same reaction after a general anaesthetic?
50%
Susceptibility to malignant hyperthermia is inherited in an autosomal dominant fashion
A 55-year-old woman is scheduled for an elective total hip replacement in 4 months time.
She has a past medical history of troublesome menopausal symptoms, hypothyroidism and hypertension. Her currently prescribed medications are Femoston (estradiol and dydrogesterone), levothyroxine, labetalol and amlodipine.
What advice should be given to her regarding her medications before the surgery?
Stop Femoston 4 weeks before surgery
Advise women to stop taking their COCP/HRT 4 weeks before surgery
Women who take hormone replacement therapy, such as Femoston, should stop taking it 4 weeks before any elective surgeries due to increase in venous thromboembolism risk.
General risk factors for VTE
(11)
- active cancer/chemotherapy
- aged over 60
- known blood clotting disorder (e.g. thrombophilia)
- BMI over 35
- dehydration
- one or more significant medical comorbidities (e.g. heart disease; metabolic/endocrine pathologies; respiratory disease; acute infectious disease and inflammatory conditions)
- critical care admission
- use of hormone replacement therapy (HRT)
- use of the combined oral contraceptive pill
- varicose veins
- pregnant or less than 6 weeks post-partum
Types of VTE prophylaxis
(5)
Mechanical:
- Correctly fitted anti-embolism (aka compression) stockings (thigh or knee height)
- An Intermittent pneumatic compression device
Pharmacological:
- Fondaparinux sodium (SC injection)
- Low molecular weight heparin (LMWH)
- reduced doses should be used in patients with severe renal impairment*
- Unfractionated heparin
- used as an alternative to LWMH in patients with chronic kidney disease*
Advice for patients
Pre-surgical interventions:
Post-surgical interventions:
Pre-surgical interventions:
- Advise women to stop taking their combined oral contraceptive pill/hormone replacement therapy 4 weeks before surgery
Post-surgical interventions:
- Try to mobilise patients as soon as possible after surgery
- Ensure the patient is hydrated
POST EXPOSURE PROPHYLAXIS
Elective Knee surgery
Elective Hip surgery
Elective Knee surgery
- *LMWH for 10 days followed by aspirin (75 or 150 mg) for a further 28 days**
- or*
- *LMWH for 28 days combined with anti-embolism stockings until discharge**
- or*
- *Rivaroxaban**
Elective Hip surgery
- *Aspirin (75 or 150 mg) for 14 days**
- or*
- *LMWH for 14 days combined with anti-embolism stockings until discharge**
- or*
- *Rivaroxaban**
A 73 year old man due to have an elective septoplasty attends the pre-op assessment clinic.
He has a past medical history of hypertension and a ST-elevation myocardial infarction 3 months ago treated with a drug-eluting stent.
His current medications include aspirin 75mg OD, clopidogrel 75mg OD, atorvastatin 80mg ON, ramipril 5mg OD, bisoprolol 5mg OD. Physical examination shows no abnormalities.
His latest ECG and echocardiogram are normal.
Which of the following is the most appropriate peri-operative management for this patient in regards to his current cardiovascular medications? (3)
Discuss with cardiology before changing medications
Usually aspirin and clopidogrel are stopped a week before surgery due to the increased bleeding risk.
However, in patients with drug-eluting stents, altering these medications may lead to stent stenosis.
It is advisable to discuss such patients with cardiology.
A 62 year old undergoes a Whipple’s pancreaticoduodenectomy for early stage pancreatic cancer.
In recovery she is re-catheterised.
You are called to recovery as nurses are concerned that her urine output was previously 40ml/hour but over the last hour she has passed 0ml.
What is the most appropriate initial management?
Check patency of catheter
A patient who has sudden reduction of urine output is a common scenario encountered post-operatively.
In this patient a key piece of information is that their catheter was recently changed.
In patients with a new catheter who suddenly report absolute anuria, the first step is to ensure catheter patency by flushing with water for injection.
A 65 year old gentleman is first on the list to have an elective inguinal hernia repair tomorrow morning.
He has a past medical history of hypertension and type 2 diabetes.
His current medications include
amlodipine 5mg OD
metformin 500mg BD
and gliclazide 40mg BD
Physical examination shows no abnormalities.
His latest HbA1c taken last week is 48mmol/mol.
Which of the following is the best advice to give the patient in regards to his diabetic medication on the day of surgery?
- Omit morning dose of gliclazide
- take metformin as normal
The patient’s recent HbA1c suggests his diabetes is well controlled.
He is first on the operating list and due to have a relatively short procedure.
Therefore there is no clinical need to omit metformin.
Gliclazide is a sulfonylurea and must be admitted due to the risk of hypoglycaemia.
More on the management of diabetic drugs peri-operatively can be found here
A 29 year old female with a history of anxiety presents to the emergency department with shortness of breath and ‘feeling like her heart is beating too quickly’.
She is complaining of bilateral paresthesia in her hands and around her lips.
Given the likely diagnosis, what is her blood gas most likely to demonstrate?
Respiratory alkalosis
This patient is likely to be suffering from panic attacks leading to hyperventilation. This causes a decrease in the partial pressure of carbon dioxide, and a respiratory alkalosis.
Causes of Type I Respiratory Failure (6)
Decreased atmospheric pressure
Ventilation-perfusion mismatch
Shunt
Pneumonia
ARDS
Pulmonary embolism
Definition of Type I Respiratory Failure (2)
Type I respiratory failure shows a low pO2 but a normal pCO2
Definition of Type II Respiratory Failure
(3)
Type II respiratory failure shows a
low pO2
high pCO2
causing an acidosis
Definition of respiratory failure
(3)
Respiratory failure leads to a decrease in the partial pressure of oxygen in the blood due to:
- inadequate ventilation
- poor perfusion
What can cause metabolic alkalosis in terms of ions?
(2)
Metabolic alkalosis is caused either by:
- the loss of hydrogen ions
- excess of bicarbonate ions
A 34 year old gentleman undergoes anaesthesia for a tonsillectomy.
He has never previously undergone general anaesthesia and has a family history of difficult ventilation following anaesthesia.
He is induced with IV propofol and suxamethonium to aid intubation.
His surgery is uncomplicated, however 30 mins later in recovery the patient appears apnoeic and difficulty is encountered with bag mask ventilation.
His observations are as follows:
- blood pressure 120/79mmHg
- pulse rate 76bpm
- respiratory rate 10 breaths per minute
- oxygen saturations 81%
What is the most likely diagnosis?
Suxamethonium apnoea
Pertinent features in the history include no history of previous anaesthesia, suxamethonium use, a family history, rapid desaturation and apnoea.
This points to a diagnosis of suxamethonium apnoea.
It occurs when a patient does not possess the enzymes (plasma cholinesterase) to metabolise suxamethonium leading to sustained activation of the drug on the post-synaptic membrane of the neuromuscular junction.
What is suxamethonium? (2)
How does suxamethonium work? (1)
In which patients is it contraindicated? (2)
What is suxamethonium?
- it is a neuromuscular blocking drug used mainly in surgery as an adjunct to anaesthetic agents
- it causes muscle paralysis which is a necessary prerequisite for mechanical ventilation.
How does suxamethonium work?
- Binding of suxamethonium to the nicotinic acetylcholine receptor results in opening of the receptor’s monovalent cation channel; a disorganized depolarization of the motor end-plate occurs and calcium is released from the sarcoplasmic reticulum.
In which patients is it contraindicated?
- suxamethonium increases intra-ocular pressure
- in patients with penetrating eye injuries or acute narrow-angle glaucoma, as
A 76 year old gentleman attends the pre-op assessment clinic for a total hip replacement.
His past medical history includes hypertension, osteoarthritis, type 2 diabetes and stage 4 chronic kidney disease.
His current medications include:
- ramipril
- metformin
- adcal-D3
He is currently asymptomatic and physical examination shows no abnormalities.
A routine set of bloods reveals a haemoglobin of 85g/L (normal range 135-180g/L) with a mean cell volume of 85fL (normal range 80-100fL).
What is the most appropriate management of this patient’s haemoglobin peri-operatively?
No action required
Generally it is important to screen for and treat underlying anaemia before surgery.
However, in patients with stage 4 CKD a Hb of 85g/L can be a normal baseline and does not necessarily need urgent correction.
As noted from the medication list this patient does not receive erythropoietin injections, however they may be a good candidate in terms of their ongoing management.
A 72 year old lady who underwent epidural anaesthesia for a total knee replacement is recovering on the ward.
She reports ongoing pain which is being managed with regular analgesia via her in situ epidural.
On examination her blood pressure is 90/50 mmHg, heart rate 104bpm, respiratory rate 18bpm, oxygen saturations 98% on room air.
She has received a fluid bolus with 500mL of 0.9% saline with no response.
What is the most definitive management of this patient?
Remove epidural
A well-recognised side effect of epidural anaesthesia is hypotension due to local anaesthesia of sympathetic nerves.
This leads to unopposed parasympathetic activity and therefore the only method of counteracting profound hypotension is removal of the epidural.
A 30 year old male is reviewed in recovery after an open reduction internal fixation of his right lower limb following a fall off a ladder.
He is hypertensive and tachycardic and is complaining of severe, worsening pain in his right leg.
Popliteal and tibial pulses are not palpable.
He has been given 10mg intravenous morphine, 100mg intravenous tramadol and 1g paracetamol in recovery.
What is the next step in the management of this patient?
Urgent fasciotomy
This patient is displaying signs of compartment syndrome, which is due to swelling and an increase in pressure within the fascia of the muscle compartment.
This can quickly lead to loss of blood supply and limb ischaemia, and treatment is with an urgent fasciotomy.
A 76 year old lady has just undergone an emergency laparotomy and is now waiting in recovery.
Her past medical history includes hypertension, peptic ulcer disease and hypercholesterolaemia and osteoarthritis.
Physical examination shows no abnormalities, however she is complaining of ongoing pain despite two oral doses of codeine 30mg and has vomited twice.
What is the most appropriate step in analgesic management?
Morphine 5mg intravenous via patient controlled analgesia
Patient controlled analgesia (PCA) is commonly used to manage post-operative pain.
A PCA will usually have a specified ‘lockout period’ whereby another dose of analgesia cannot be given until this time has elapsed.
Morphine is a strong opioid and is therefore appropriate given that codeine has been ineffective.
A 12 year old boy is brought into the emergency department after a road traffic accident.
He is talking and complaining of pain in his left leg, and discomfort in the back of his neck.
He has been stabilized in a collar and blocks and is awaiting review from the trauma team.
He weighs 40kg.
What is the most appropriate treatment for the management of pain in this patient?
IV morphine
This patient has been involved in a serious, high impact road traffic accident and is likely to be in a lot of pain.
Unlike for patients on the ward, where following the WHO pain ladder is more appropriate, rapid assessment and treatment of his pain with intravenous morphine is the most suitable treatment for him.
A 65 year old gentleman is recovering on the ward 3 hours after a cerebrovascular angiography and coiling for an intracranial aneurysm.
He remains drowsy and has not taken fluid orally since fasting for his procedure.
He has a past medical history of polycystic type 2 diabetes and chronic liver disease.
His current medications include metformin 500mg BD and ramipril 5mg OD.
An arterial blood sample is taken and the results are as follows:
- pH = 7.31 (7.35-7.45)
- pCO2 = 4.8kPa (4.5-6.0)
- pO2 = 11kPa (10-14)
- HCO3 = 18mmol/L (22-28)
- Lactate = 6mmol/L (<2)
What is the most appropriate next step in management?
What does he have?
- 500mL 0.9% saline bolus
- The patient’s arterial blood gas shows a metabolic acidosis.
Metformin can cause a lactic acidosis by impairing lactic acid metabolism in the liver.
In a patient with chronic liver disease this risk is more likely.
Another possible cause of the lactic acidosis may be through pre-renal acute kidney injury from mild dehydration.
A lactic acidosis is initially managed with a fluid bolus. This will improve the renal component to his acidosis although it may not fully treat the liver component.
Causes of Type A lactic acidosis
(7)
Tissue hypoxia (Type A)
- Shock (e.g. cardiogenic, hypovolaemic, haemorrhagic)
- Hypoxia
- Acute mesenteric ischaemia
- Limb ischaemia
- Severe anaemia
- Seizures
- Vigorous exercise
Causes of type B lactic acidosis
(5)
Abnormalities in metabolism of lactate (Type B)
- Diabetic ketoacidosis
- Cancer
- Liver disease
- Inborn errors in metabolism
- Drugs:Aspirin, Metformin - impairs liver metabolism of lactate
A patient is brought into the emergency department following a road traffic accident.
He was the front seat passenger of a car in a head-on collision traveling at 60mph.
He is opening his eyes to speech, complaining loudly of pain in his right lower limb (which has sustained an open tibial fracture) and cannot concentrate on questions being asked.
He is asking for his friend and cannot identify where he is.
He intermittently follows your command to squeeze your fingers with his left hand but cannot do the same with his right.
What is his GCS score?
13
The patient scores as follows; E3 V4 M6.
The GCS score aims to objectively assess a patient’s level of consciousness.
The scale is composed of eye, voice and motor responses. The three values are considered separately as well as combined. Maximum score for eye responses is 4.
Maximum score for voice responses is 5.
Maximum score for motor responses is 6. The minimum score for each type of response is 1.
The lowest possible GCS is 3 (deep coma or death), while the highest is 15 (fully awake person).
A 67 year old male patient is brought into the emergency department after a fall.
He smells strongly of alcohol and appears unkempt.
On examination he does not open his eyes to pain, but groans and withdraws to a painful stimulus.
What is the most appropriate initial management of this patient?
Urgent CT head
This patient has risk factors for a subdural haematoma - decreased GCS, alcohol excess and history of a fall.
A CT head is needed to rule out a bleed.
What is goserelin
Goserelin, sold under the brand name Zoladex among others, is a medication which is used to suppress production of the sex hormones, particularly in the treatment of breast and prostate cancer.
It is an injectable gonadotropin releasing hormone agonist.
A 75 year old man with a diagnosis of metastatic prostate cancer presents to his GP complaining of increasing pain.
He is currently treated with goserelin injections.
His current pain relief regimen consists of;
- 25 mg MST Continus BD
- 10mg Oramorph for breakthrough pain
He is currently using four sachets of Oramorph per day but his pain is not controlled.
What is the single most appropriate regimen to prescribe for this patient to control his pain?
60 mg MST Continus BD and 20 mg Oramorph PRN
The patient is currently on 90mg total morphine sulphate and his pain is not controlled.
It is recommended to increase the dose by 1/3 which would take the total morphine required to 120mg.
- This is best split as two separate 60mg doses
- Breakthrough pain using Oramorph is 1/6 of the total morphine sulphate requirement 120/6 = 20mg.
A 72 year old lady is in recovery following a Hartmann’s procedure for a perforated sigmoid volvulus.
Physical examination shows no abnormalities.
She received a dose of cyclizine 50mg IV intra-operatively, however she is complaining of post-operative nausea and has vomited twice in the last 20 minutes.
What would be the most appropriate anti-emetic to prescribe for her?
Which receptor does it target?
Ondansetron 8mg IV
In order to prevent post-operative nausea and vomiting the recommended method is so called multi-modal analgesia, whereby anti-emetics of different mechanisms are used in combination for their synergistic effect.
Ondansetron is a centrally acting 5HT3-antagonist, but also acts upon chemoreceptors in the gut.
It is therefore ideal for post-operative nausea and vomiting which is often due to irritation of the gut by agents commonly used in anaesthesia.
A 29 year old female with a history of depression and hay fever is brought into the emergency department confused and drowsy.
Her drug history includes amitriptyline and loratadine.
She has a temperature of 37.9 degrees Centigrade, appears flushed, and on examination her pupils are dilated.
Her blood gas shows a pH of 7.25 (7.35-7.45).
What is the likely cause?
What is the most appropriate treatment for this patient?
Sodium bicarbonate
Patients with a suspected tricyclic antidepressant overdose, who are acidotic or have an arrhythmia should be managed according to the ABCDE algorithm and also with sodium bicarbonate.
A 28-year-old motorcyclist is brought into the emergency room after a road traffic accident.
Imaging shows a mid-tibial, displaced fracture, which is treated with open repair and intra-medullary nail insertion, then placed in a cast.
On his first post-operative day, he complains of severe pain in the leg.
He can move both his ankle and knee in all directions without worsening of the pain but screams when you passively plantar flex the foot.
Dorsalis pedis pulse is not felt.
What would be your first step in the management of this patient?
Immediate removal of cast
The cast is adding pressure to a closed compartment and exacerbating this gentleman’s compartment syndrome
removing it would be your first step.
A 59 year old gentleman presents feeling generally unwell.
An arterial blood gas shows a :
pH of 7.31 (7.35-7.45)
pO2 7.5 kPa (>12)
pCO2 of 7.1 kPa (4.3-6).
What type of respiratory failure does this demonstrate?
What are the causes of this type of respiratory failure?
Causes of Type II Respiratory Failure (5)
- COPD
- Brain stem disease/lesion
- Bronchitis
- Motor neuron disease
- Deformity e.g. ankylosing spondylitis, kyphoscoliosis
A 53 year old woman arrives in the anaesthetic room.
She is due to have a laparoscopic fundoplication.
Her past medical history includes polycystic ovarian syndrome and a severe hiatus hernia refractory to medical treatment.
Her current medications;
- atorvastatin 20mg ON
- omeprazole 20mg OD
Her pre-op assessment was normal.
What is the most appropriate method of anaesthetic induction in this patient?
Rapid sequence induction
We are told the patient has a history of a symptomatic hiatus hernia.
In such a patient the risk of aspiration during induction is high, and therefore rapid sequence induction is preferred.
Rapid Sequence Induction Definition
Rapid sequence induction (RSI) is the method of coordinating the administration of rapidly acting induction agents to produce anaesthesia and muscle relaxation
followed by prompt intubation
resulting in a secure airway with the minimal risk of aspiration.
What is the function of Atropine? (1)
How does Atropine work? (1)
- Atropine is used for symptomatic bradycardia in the absence of reversible causes.
- It inhibits vagal activation on the heart and can therefore temporarily revert tachycardia to a normal sinus rhythm.
Side effects include:
- tachycardia
- pupil dilation
- dry mouth
- urinary retention
- inhibition of sweating (anhidrosis)
- blurred vision
- constipation
What is the function of Adenosine? (1)
How does Adenosine work? (2)
What is a common contra-indication to adenosine? (1)
Adenosine is used to treat patients with supraventricular tachycardias,
They are used if vagal manoeuvres are unsuccessful and work by temporarily blocking the conduction through the atrioventricular node (AV node).
In patients with asthma verapamil should be used in place of adenosine.
A 75 year old woman is brought into the emergency department following a fall down 2 flights of stairs. She is opening her eyes to voice. She fails to answer your questions but is calling out random words and is unable to form a sentence. She moans and withdraws from painful stimuli.
What is her GCS score?
E4V3M4
What are “panda eyes”?
(2)
Classical ‘panda eyes’ are a sign of a base of skull fracture
It may also indicate an intracranial bleed, C-spine fracture and other injuries.
A 72 year old gentleman has been listed for a carotid endarterectomy following a doppler ultrasound of the carotids revealing significant stenosis.
He has a past medical history of hypertension, recurrent TIAs and a metallic mitral valve.
His current medications include amlodipine, warfarin, clopidogrel and atorvastatin.
His target INR range is 3-4.
His latest INR reading a week ago was 3.4.
What is the most appropriate peri-operative management with regards to his warfarin dose?
Stop warfarin and bridge with treatment dose low molecular weight heparin (LMWH) 5 days prior to surgery
Warfarin is typically stopped in the peri-operative period due to the bleeding risk it poses.
However, with a history of recurrent TIAs and a metallic valve this patient is at high risk of further thromboembolic events, and therefore bridging with a LMWH is recommended.
A 25 year old female patient is on the wards recovering from a thyroidectomy for thyroid carcinoma.
The post-operative period has been complicated by nausea, vomiting, and pain around the wound site so she has been prescribed post-operative medication accordingly.
24 hours after surgery she becomes increasingly restless and is noted to have forced extension of the neck, rigid opening of the jaw, and sustained upward deviation of the eyes.
Which drug was most likely cause of this presentation?
What can be done to reverse this?
Treatment with a dopamine antagonist
Metoclopramide appears to bind to dopamine D2 receptors
This describes an acute dystonic reaction most likely secondary to metoclopramide.
Reactions to metoclopramide, an antidopaminergic anti-emetic, can cause acute dystonic reaction, clasically in patients younger than 30 years old and when doses of greater than 30 mg per day are administered.
Metoclopramide should be discontinued.
An anticholinergic agent, such as procyclidine or biperiden, can be administered to alleviate the acute dystonic reaction.
A 28-year-old man is brought into A&E with a reduced level of consciousness.
His friends believe he has ingested large quantities of an unknown substance.
He opens his eyes briefly on pressure on the fingertips, but not in response to voice.
He is making moaning sounds but no words or sentences.
On assessment of his motor response, there is abnormal flexion in response to pain, with no localisation.
What does this patient score on the Glasgow Coma Scale (GCS)?
7
This is the correct answer.
Eye-opening to pain and incomprehensible sounds (moans and groans) each score two points.
Flexion response to pain scores three points.
Remember that when a patient’s GCS is less than 8, intubation must be considered to secure the airway.
A 71 year old gentleman has just undergone a left hemicolectomy for malignancy.
He has a history of hypertension and type II diabetes mellitus, but is otherwise fit and well.
He is complaining of severe pain in his abdomen.
- His heart rate is 111
- His blood pressure is 84/56
- saturating 98% on 2L via a nasal cannula.
Which of the following is the next best step in the management of this patient?
500ml bolus of intravenous crystalloid
A fluid bolus would treat the hypotension and tachycardia, as this is likely hypovolemic in origin.
This will not treat the underlying cause of shock, which in this patient is most likely to be a post-operative bleed, requiring surgical intervention.
However, the next best treatment for this patient is to restore blood pressure.
A 67 year old gentleman has just undergone an emergency Hartmann’s procedure for a perforated rectal cancer.
He is now waiting in recovery.
He has had a 1 litre bag of 0.9% saline IV over the last 24 hours with no oral intake.
His catheter has drained 1500mL over the last 24 hours.
His weight is 70kg.
Which of the following would be the most appropriate fluid volume to prescribe him over the next 24 hours?
2.5 litres
The NICE guidelines for prescribing maintenance fluids recommend a total volume of 25-30ml/kg/day.
This patient also has a 500mL fluid deficit.
Therefore, a total volume in the range of 2250-2600mL would be most appropriate.
A 19 year old male is brought into the emergency department after a collapse.
He was involved in a fight 6 hours previously, but his friend reports he was fine afterwards.
He is not opening his eyes, but moans and flexes in response to a painful stimulus.
What is the most likely cause of his collapse?
Extradural haematoma
This patient has the history and symptoms of a patient with an extradural bleed, typically arising due to trauma to the face, and often with a lucid interval prior to collapse.
Characteristics of Extradural haematoma
A patient with an extradural bleed will typically present with a
lucid interval prior to collapse
A 26-year-old diver has presented to the Emergency Department complaining of blurry vision and watery rhinorrhoea that increases on bending forwards.
He has recently returned from a diving expedition and reports blunt trauma to the head.
Which is the most appropriate next step in the management of this patient?
CT head
The patient has presented with possible fracture of the anterior skull base due to blunt trauma during diving.
Watery nasal discharge should arouse suspicion of CSF rhinorrhoea, especially if discharge is increased on bending forwards.
The current standard in diagnosis of suspected fracture of the anterior skull base is CT (axial and coronal planes).
