3. Trauma & Orthopaedics Flashcards
You see a patient two days following left total knee replacement. He complains of right foot drop since surgery. He had a spinal anaesthetic and wonders if this was the cause, although no complications were
reported at the time. He is otherwise well and clinical examination confirms weak dorsiflexion of his right foot. What is the most likely cause?
A. Cerebrovascular accident
B. Poor intraoperative positioning and padding
C. Spinal abscess
D. Spinal haematoma
E. Spinal nerve root injury
- B
Postoperative complications may result from surgical, anaesthetic, or non-medical factors including
patient positioning.
Intraoperative positioning and padding may lead to prolonged pressure on the common peroneal nerve during anaesthesia which is a well-documented cause of postoperative foot drop.
One must ensure adequate padding around the fibular head when positioning patients under general or regional anaesthesia for long periods of time. A central neurological cause is unlikely to cause such well-defined peripheral nerve lesions and in any case is very rare. Treatment is conservative and the transient neuropraxia will usually pass. However, the patient should also be counselled of the possibility that this may be a permanent injury
A frail 86-year-old female requires neck of femur fixation surgery.
Her BMI is 18. Her core temperature is 36.1°C prior to induction of anaesthesia. Which process will be responsible for the largest amount of
heat loss during anaesthesia and surgery?
A. Radiation
B. Convection
C. Respiration
D. Evaporation
E. Conduction
- A
These five mechanisms all contribute to heat loss from the body. Around 40% is estimated to be by
radiation which is the largest.
- A 67-year-old man completed a 2-unit blood transfusion during his revision hip arthroplasty 8 hours ago. He has developed a fever, urticarial rash, and back pain. His heart rate is 132, BP 95/50, respiratory rate is 32.
He has passed 130 mL of very dark urine since surgery.
His posttransfusion blood results show a haemoglobin level of 75 g/L. What is the most likely explanation for his deterioration?
A. Transfusion-related acute lung injury
B. Transfusion-associated circulatory overload
C. Transfusion-associated graft versus host disease
D. Transfusion-related bacterial infection
E. Acute haemolytic transfusion reaction
- E
Acute haemolytic transfusion reactions present within 24 hours after a transfusion of ABO incompatible red blood cells.
Antigens on the donor red cells react with antibodies in the recipient’s plasma leading to degranulation of mast cells, inflammation, increased vascular permeability, and hypotension.
Intravascular haemolysis can occur leading to disseminated intravascular coagulation
(DIC), renal failure, and death.
The treatment is supportive. Inadvertent transfusion of ABO-incompatible blood components resulting in serious harm or death is classified as a Never Event by the Department of Health. All the others are possible consequences of blood transfusion but the symptoms, signs, and timescale support E as the correct answer
- A 28-year-old woman presents with a trimalleolar fracture of her left ankle. She is haemodynamically stable. She is 27 weeks pregnant. She has had an uneventful pregnancy so far and has no other past medical history. What would be the most appropriate anaesthetic management?
A. Recommend conservative management of the fracture until 3rd trimester
B. General anaesthesia with a laryngeal mask airway (LMA) in situ
C. General anaesthesia and intubation without a rapid sequence induction
D. General anaesthesia and intubation with a rapid sequence induction
E. Spinal anaesthesia
- E
A trimalleolar fracture cannot be managed conservatively. In general, the second trimester is
preferred for semi-elective procedures that can’t be deferred until after the baby is delivered.
There is no benefit in delaying until the third trimester. Elective surgery should be postponed if
possible until at least six weeks post-partum. Lower oesophageal sphincter tone is reduced from
early gestation and intra-abdominal pressure increases during the second trimester so an LMA is
not recommended. If a general anaesthetic is necessary, it should be a rapid sequence induction (RSI) with cricoid pressure from the second trimester. Regional anaesthesia is highly desirable as
airway management can be more difficult in pregnant patients. The patient would thus maintain her
own airway and the spinal would also minimize fetal drug exposure and give good postoperative
analgesia. A spinal anaesthetic would therefore be the preferred choice in this patient.
5. A 59-year-old woman had an elective total knee replacement earlier today under spinal block which included 0.2 mg of preservative-free morphine. She is now complaining of severe itch around her neck and chest. She is otherwise well. What would be the most effective treatment for her symptoms? A. Chlorpheniramine B. Diclofenac C. Hydrocortisone D. Naltrexone E. Ondansetron
- D
Itch is a common side effect of intrathecal opiates. Its mechanism is not fully understood. Opioid
itching is not thought to be secondary to histamine release so chlorpheniramine is unlikely to
be effective. Prostaglandins are known to modulate c fibre transmission and seem to have a
role in opioid induced itch but studies have shown only limited effect form anti-inflammatories
like diclofenac. Steroids such as hydrocortisone have no place in the treatment of itch. Opioid
antagonists such as naloxone and naltrexone are associated with the greatest success. Low dose is
required so as not to reverse the analgesic benefits. Use of ondansetron for pruritis is not first line
and evidence for its use is lacking except perhaps in obstetrics.
- A 72-year-old man is listed for an elective total hip replacement. Which of the following is the strongest indication for the use of perioperative cell salvage?
A. Preoperative haemoglobin level of 13 g/dL
B. Preoperative ferritin level of 150 ng/L
C. Von Willebrand’s disease type 3
D. 75 mg of aspirin stopped five days ago
E. Anticipated blood loss of 500 mL
- C
The general indications for cell salvage are:
• Surgery where there is expected blood loss > L or >20% blood volume, e.g. revision hip replacement
• Preoperative anaemia or major risk factors for bleeding such as Von Willebrand’s disease.
The WHO classifies anaemia as <3 g/dL in males (<2 g/dL in females)
- Iron deficiency anaemia is common. Normal ferritin levels are 41–400 µg/L
- Patients with rare blood group or antibodies
- Patients who refuse conventional blood transfusion, e.g. Jehovah’s Witnesses
- A 79-year-old female who sustained a fractured neck of femur the previous day is scheduled for operative fixation with a dynamic hip screw.
She has a past medical history of type 2 diabetes mellitus on metformin.
She denies any history of chest pain, breathlessness, or syncope. Which of the following is most likely to result in postponement of surgery?
A. A loud ejection systolic murmur on auscultation
B. Blood tests show urea 8.0 mmol/L and creatinine 158 mmol/L
C. Fasting blood glucose this morning was 16 mmol/L
D. ECG (electrocardiogram) shows atrial fibrillation with rate of 92 bpm
E. SpO2 96% on 2 L/min oxygen, RR 18 breaths/min. Apyrexial
- C
Surgery should be postponed only when there is clear clinical benefit to doing so.
Many of the population have an ejection systolic murmur and in the elderly it is often due to aortic sclerosis.
Should echocardiography confirm aortic stenosis, there is no reasonable acute treatment to reduce the risk of anaesthesia and hip surgery.
Thus there should be no delay awaiting echocardiography. Mild derangement of urea and electrolytes is seen in 40% of patients presenting with a hip fracture.
There is commonly a period of dehydration followed by intravenous fluids in hospital.
This is not an indication to delay surgery. The patient remains clinically well and respiratory parameters are
close to normal for this patient’s age with a low oxygen requirement.
Atrial fibrillation needs no specific treatment here in the absence of tachycardia.
Uncontrolled diabetes with a blood sugar of
16 mmol/L should be controlled acutely prior to surgery. This is well above the normal limit and
will become further deranged during surgery.
A high glucose will predispose to wound infection.
Prosthesis infection is a severe complication when metal is implanted in orthopaedics.
- You anaesthetize a 34-year-old man for an open reduction and internal fixation (ORIF) of scaphoid fracture under general anaesthesia.
You perform an ultrasound-guided radial nerve block above the elbow as part of your analgesia plan. Which is the most accurate statement regarding the performance of this block using ultrasound?
A. A high-frequency curvilinear probe provides the best images
B. A reduced concentration of local anaesthetic is likely to be needed compared with the landmark technique
C. The radial nerve appears hypo-echoic
D. The probe should be orientated to show the nerve in the short axis
E. Use of ultrasound removes risk of intravascular injection of local anaesthetic
- D
A high-frequency linear probe would provide the best images. A reduced volume of local anaesthetic
is likely to be sufficient rather than reduced concentration. The radial nerve will look hyper-echoic.
The probe can trace the nerve in the long axis but this block is best performed in the short axis to
give a good view of surrounding structures. Use of ultrasound should reduce the risk of intravascular
injection but does not remove it and careful aspiration before injection of local anaesthetic is
required.
- A 70-year-old lady is listed for a left dynamic hip screw for fixation of her
fractured neck of femur.
Her medical history includes hypothyroidism, hypertension, and depression. Her medication includes levothyroxine, bendroflumethazide, amlodipine, and phenelzine. You administer a spinal anaesthetic and 5 min later her heart rate decreases to 57 bpm and her blood pressure drops to 85/46 mmHg despite 500 mL of
Hartmann’s solution. What is the most appropriate drug to improve her cardiovascular status?
A. Phenylephrine
B. Metaraminol
C. Adrenaline (epinephrine)
D. Noradrenaline (norepinephrine)
E. Ephedrine
- A
The cardiovascular compromise is most likely due to the sympathectomy caused by the spinal
anaesthetic.
Phenelzine is a non-selective irreversible mono-amine oxidase inhibitor. Administration of indirectly acting sympathomimetic agents such as ephedrine or metaraminol may precipitate a severe hypertensive reaction.
The next best choice to treat her blood pressure drop
secondary to probable vasodilation is phenylephrine.
Adrenaline (epinephrine) and noradrenaline
(norepinephrine) would be safe to use; however, due to their potency they would not be considered a first line choice.
- A 48-year-old woman presents with severe pain, swelling, and erythema of her left forearm.
The only history of trauma is of a small scratch while
gardening a week ago. Her C-reactive protein (CRP) is 198, her white cell count (WCC) is 28, and her creatinine level is 180 µg/L. What is the gold standard method to confirm/refute necrotizing fasciitis as the
diagnosis?
A. Blood cultures B. Computed tomography scan C. Percutaneous needle aspiration D. Surgical exploration and tissue biopsy E. Creatinine kinase level
- D
Blood cultures may be useful to guide antibiotic treatment but can take 48–72 hours to become
positive.
There is a laboratory result-based risk indicator scoring system for necrotizing fasciitis which gives scores for CRP, WCC, haemoglobin, creatinine level, sodium, and glucose levels.
This can help differentiate between cellulitis and necrotizing fasciitis. However, the diagnosis of
necrotizing fasciitis is essentially clinical, and D is the gold standard to confirm.
Percutaneous needle aspiration may be useful and can be sent for gram stain and culture but tissue biopsy is the investigation of choice. Imaging such as computed tomography or magnetic resonance imaging may
be useful but should not delay surgery
- A 76-year-old lady is on the trauma list this morning for a femoral nailing. Her past medical history includes severe dementia, stable angina, and hypothyroidism. Her haemoglobin is 98 g/L. You notice in the orthopaedic a single sentence stating the patient is a Jehovah’s witness. What is the best way to proceed?
A. Postpone operation until you can speak to her next of kin to see what blood products they will permit
B. Proceed with a general anaesthetic and femoral nerve block. Give tranexamic acid and
avoid transfusion of blood products even if life-threatening haemorrhage
C. Proceed with a general anaesthetic and femoral nerve block. Give tranexamic acid but use
blood products if required to save her life as an Adults with Incapacity form is signed
D. Postpone operation until you speak to relatives and verify what her wishes would be in the event of life-threatening haemorrhage
E. Continue with spinal anaesthesia and femoral nerve block. Give tranexamic acid and avoid
blood products even in life-threatening haemorrhage
11 D
This is a question about consent. The operation is urgent rather than emergency so it is reasonable to postpone to allow the patient’s wishes to be verified preferably with an advance directive already in place.
The family can provide information but ultimately cannot accept nor refuse treatments on behalf of the patient.
- A 68-year-old man has sustained a hip fracture. He is listed for hemiarthroplasty.
There are no other injuries apparent. He has stable angina and no other significant medical history. His resting ECG is normal. His full blood count reveals a haemoglobin of 10.9 g/dL. The most appropriate management is:
A. Preoperative transfusion 1 unit packed red cells
B. Preoperative transfusion 2 units packed red cells
C. Crossmatch 2 units packed red cells and proceed
D. Crossmatch 4 units packed red cells and proceed
E. Grouped sample and proceed
- C
Preoperative anaemia occurs in around 40% of hip fracture patients. It is multifactorial resulting
from fracture site bleeding, haemodilution, pre-existing anaemia, or chronic disease.
Haemorrhage and haemodilution may result in a fall of around 2.5 g/dL.
Anaemic patients are therefore at risk of significant worsening of anaema postoperatively risking ischaemia.
Preoperative transfusion should
be considered at Hb <9 or Hb <10 for those with a history of ischaemic heart disease as per this
case. This patient probably just escapes the need for transfusion preoperatively. If the haemoglobin
is 10–12 g/dL, crossmatching 2 units preoperatively and vigilance with respect to intraoperative
bleeding should suffice.
The surgery planned is not suggested to be more complex and a requirement for a 4-unit transfusion postoperatively would be unusual. Cell salvage is probably more amenable to periprosthetic fracture or revision surgery.
- A 68-year-old man presents to hospital two weeks after elective right primary total hip replacement performed under uncomplicated spinal anaesthesia. He had complained of left thigh pain during his hospital admission but was reassured and sent home.
He now reports left-sided reduced sensation in his lateral thigh skin with an unpleasant burning
sensation. Neurological examination is otherwise normal. The most likely cause is:
A. Meralgia paraesthetica B. Soft tissue thigh injury C. Conus injection D. Compartment syndrome E. Epidural haematoma
- A
The lateral cutaneous nerve supplies skin sensation over the lateral thigh only.
It is a pure sensory nerve. It most often becomes injured by entrapment or compression where it crosses the inguinal ligament near the anterior superior iliac spine peripherally. This is most often seen in association with obesity, but also in other conditions that increase intra-abdominal volume such as pregnancy and ascites, in which the nerve may be kinked or compressed by the bulging abdomen as it leaves the pelvis.
Meralgia paraesthetica is the unpleasant syndrome of paraesthesia and pain in the lateral and anterolateral thigh with no motor weakness.
There is no direct thigh injury itself, with the nerve
injury being more proximal. This patient’s left-sided symptoms are on the non-operative side and
may result from a dependent side compression injury during right-sided hip surgery.
Usually the condition improves with conservative (non-surgical) treatment. Central damage from complications
of neuraxial block is rare
- A 68-year-old man presents to the Emergency Department having fallen.
A chest X-ray shows three fractured ribs on his left side. He is Glasgow Coma Scale 15 with no other injury. He has well-controlled hypertension and mild angina. His pain has been controlled after titration of 0.1 mg/kg intravenous morphine and 1 g of paracetamol.
His dynamic pain score is now 1. What would be the most appropriate initial pain management plan?
A. Regular paracetamol
B. Insert a thoracic epidural
C. Insert a left paravertebral catheter
D. Morphine sulphate slow-release tablets twice a day with oramorph for breakthrough and regular paracetamol
E. An intravenous morphine patient-controlled anaesthesia with regular paracetamol
- D
The number of ribs fractured correlates with the severity of the injury, and together with age
they are the most important determinants of morbidity and mortality.
Four or more fractured ribs are associated with higher mortality rates and seven or more have a mortality rate of 29%.
The associated pain is notoriously difficult to manage, but effective analgesia started promptly prevents hypoventilation, enables deep breathing, adequate coughing with clearance of pulmonary secretions, and compliance with chest physiotherapy.
A stepwise multimodal approach to pain
should be implemented.
This patient is not in a high-risk group and already has reasonable pain control with paracetamol/opioids alone. Additional regional anaesthesia should be considered when pain is not controlled or the patient is at high risk of respiratory complications which
often appear 48–72 hours after injury.
Potential regional techniques include thoracic epidural,
paravertebral, and intercostal blocks or serratus anterior block
- When considering risk of systemic local anaesthetic toxicity, which site
for a regional block carries the highest risk?
A. Brachial plexus
B. Intercostal
C. Caudal
D. Epidural
E. Femora
- B
Intercostal block carries the highest risk and is a reminder to consider the site of injection as a risk
factor for local anaesthetic toxicity.
Some sites carry higher risk of direct intravenous injection, e.g. stellate ganglion block, and others carry increased risk of absorption toxicity due to injection into a highly vascular area, e.g. the pleura. In order from lowest to highest risk are subcutaneous, femoral,
brachial plexus, epidural, caudal, and intercostal blocks.
