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Flashcards in Mixture Deck (55):
1

A 4-year-old child is brought to casualty after spilling hot tea causing superficial scalds on her chest and legs, of approximately 3% surface area. She is crying with pain and will not permit examination.

Oral opiates

Burns management is dictated by the extent and degree of burns.

The extent of burns in an adult is calculated by the 'rule of nines' and the degree by the depth of the burn.

In first degree burn, only the epidermis is involved and is manifested by erythema only.
In second degree burn, the dermis is burnt and it is manifested by blisters and excruciating pain due to exposed nerve endings in the burnt areas.
Third degree burns extend to the deeper tissues but tend to be less painful as the nerve endings are burnt as well.
There is thick proteinaceous exudate that forms the eschar in these areas of deep burns which takes about 21 days to heal.

The child needs analgesia for comfort and to facilitate complete assessment.

2

A 26-year-old female presents with generalised irritation and erythematous skin after sunbathing on the beach.

Emollient cream

Irrigation of the skin may help reduce the irritation from the sunburn. The patient would also benefit from an emollient cream.

3

A 4-year-old boy born in North Africa has presented with recurrent chest infection and wheeze since birth. On auscultation he has an ejection systolic murmur and a rumbling mid-diastolic murmur. He is also noted to have a fixed and widely split second heart sound.

Atrial septal defect
There are two main types of atrial septal defect.

1. Ostium secundum deficency of the foramen ovale and atrial septum.
2. Ostium primium defect of the atrioventricular septum.
Both present with similar symptoms.

All symptomatic children should be offered surgery, which consists of closing the defect primarily with sutures or with a patch.

4


A 6-week-old boy is noted to have a loud systolic murmur at his six week check. The mother reports that he feeds well and is he is on the 50th centile for weight and height.

Ventricular septal defect
Ventricular septal defects (VSDs) are common and are of two main types

1. Perimembranous - close to the tricuspid valve.
2. Muscular - completely surrounded by muscle.
Most children are asymptomatic with most VSDs closing spontaneously within the first few years of life.

Symptoms include failure to thrive, recurrent chest infections and heart failure. Surgery is indicated if there are severe symptoms with failure to thrive or pulmonary hypertension. Untreated pulmonary hypertension will progress to irreversible damage of the pulmonary capillary vascular bed.

5


A 6-week-old boy is noted to have a continuous murmur. The mother reports that he feeds well and is he is on the 50th centile for weight and height.

Patent ductus arteriosus
The ductus arteriosus connects the pulmonary artery to the descending aorta. Failure to close shortly after birth frequently occurs in preterm or sick infants. In other children it is due to a defect in the muscle of the duct. Children are usually asymptomatic but may develop signs of heart failure. If the PDA fails to close then surgical/transvenous closure is advised to abolish the lifelong risk of bacterial endocarditis.

6

A 67-year-old woman presents in atrial fibrillation. On auscultation there is a loud first heart sound, and a rumbling diastolic murmur.

Mitral stenosis
Nearly all cases of mitral stenosis are the result of rheumatic fever. The infection follows a throat infection with beta-haemolytic Streptococci whose antigen cross reacts with various tissues of the body. The mitral valve is the most common and most severely affected. Clinically atrial fibrillation is common, the diastolic murmur is the result of turbulence as the left ventricle fills through the stenosed valve. The natural history is of steady deterioration.

7

A 72-year-old man presents with fainting following exertion. On examination he has a harsh ejection systolic murmur.

Aortic stenosis
In aortic stenosis effort syncope is thought to arise from cardiac reflexes stimulated when the heart becomes overloaded. The murmur is best heard over the aortic area and radiates well to the carotid arteries. The majority of stenoses are degenerative, occurring on previously bicuspid valves with presentation in the later years of life. Some are congenital and may present at any age. Those secondary to rheumatic fever often also have mitral valve involvement and present in middle age.

8

A 73-year-old woman with known congestive cardiac failure presents with peripheral and sacral oedema, on examination there are prominent distended neck veins, a large pulsatile liver and clinical ascites. On auscultation there is a pansystolic murmur.

Tricuspid reguritation
Tricuspid regurgitation is relatively common and is usually secondary to heart failure; it occurs when the right ventricle enlarges sufficiently to stretch the valve ring. The murmur is usually indistinguishable from mitral regurgitation. The condition may resolve with treatment of the heart failure but usually requires an annuloplasty.

9

Regarding cannulation for cardiopulmonary bypass, please choose the most appropriate answer from the list.
In which structure is the venous cannula placed when a patient is undergoing a tricuspid valve replacement?

Vena cava
When the right side of the heart has to be opened, separate cannulae are inserted into the superior and inferior venae cava. Purse-string sutures are snared around the incisions to produce a blood- and airtight seal.

10

In which structure is the arterial cannula from the cardiopulmonary bypass circuit placed?

Ascending aorta
The blood drained from the heart is passed through the oxygenator in which it is separated from a gas mixture by a system of membranes. The blood is then returned to the patient under pressure through a roller pump via an arterial filter and air bubble detector. The arterial cannula is usually positioned in the ascending aorta.

11

In which structure is the venous cannula placed when a patient is undergoing a mitral valve replacement?

Right atrium
Cardiopulmonary bypass allows whole body perfusion in which the pumping action of the heart and oxygenation of blood by the lungs are replaced by an extracorporeal circuit. The returning venous blood is diverted from the heart using a large bore cannula inserted in the right atrial appendage.

12

A 52-year-old man undergoing resection of the right middle lobe of the lung.

Right posterolateral
The posterolateral thoracotomy is the most common incision for pulmonary resection. This incision also provides optimal exposure of mediastinal and hilar structures plus the hemidiaphragm on each side. On the right side it provides the best exposure of the tracheal carina.

13

A 21-year-old man stabbed on the right hand side of his neck, and is found to have a massive haemothorax when a chest drain is inserted.

Transverse anterior thoracotomy (clam shell incision)
The clam shell approach is used to gain quick access to the superior mediastinum. The manubrium is divided with bone cutters to the level of the manubrial-sternal joint. The intercostal muscles in the second intercostal space are divided to the midaxillary line where the rib is divided on each side. This forms the so-called 'clam shell' opening.

14

A 65-year-old woman undergoing a mitral valve replacement.

Median sternotomy
A midline sternotomy gives optimal access to the heart, ascending aorta, aortic arch, arch vessels and both hemidiaphragms. However, median sternotomy affords a limited exposure of both pleural spaces and the anterior hilar structures. Median sternotomy results in the least compromise of pulmonary function in the early post-operative period of any thoracic incision. It also produces less postoperative pain than a thoracotomy.

15

The chest radiograph of a 59-year-old male smoker shows a cavity with an air-fluid level. Bronchoscopy excludes malignancy.

Lung abscess
Lung abscess may follow suppurative pneumonia if accompanied by bronchial obstruction. Bronchoscopy is essential to exclude bronchial obstruction by benign or malignant conditions, bacteriology may also be obtained. Percutaneous catheter drainage is required if the patient is toxic. Pulmonary resection is required if conservative therapy fails.

16

The chest radiograph of a 43-year-old North African man reveals multiple cysts near the hilum. He is otherwise well.

Lung hydatid
Hydatid disease is now rare in Europe. The worm responsible is Echinococcus granulosus. Man is usually an unwitting intermediate host from contact with dogs. Hydatid cysts are more common in the liver, and when found in the lung are usually associated with liver involvement. Lung cysts should be treated surgically with enucleation of the cysts.

17

The chest radiograph of a 39-year-old woman reveals bilateral cystic changes with 'tram-line' shadows. She has suffered repeat severe chest infections since childhood. Recently she has developed haemoptysis.

Bronchiectasis
Bronchiectasis results from destruction of the normal bronchial architecture. The damage is usually initiated in childhood when severe infections are exacerbated by bronchial obstructions. With chronic infection there is progressive bronchial dilatation and thickening (seen as tramlines on chest radiograph) and mucus gland hyperplasia. Pulmonary resection is only indicated if bronchiectasis is localised and unilateral.

18

A 62-year-old woman has undergone a left upper lobe resection for a solitary tumour. One week following the procedure she is dyspnoeic and the drain fluid has a milky appearance. A fluid level is seen on the chest radiograph.

Chylothorax results from damage to the thoracic duct and occurs after 0.5-1% of major cardiothoracic procedures. Aspirate is the typical milky fluid of chyle. The diagnosis should be confimed by analysis of the fluid. Chylomicrons are only found in true chylous effusions. If the triglyceride level is over 110 mg/100 ml the diagnosis is 99% certain. If it is below 50 mg/110 ml there is only a 5% chance the fluid is chyle. Conservative treatment is total parenteral nutrition (TPN) and nil by mouth supplemented by octreotide. However, chylothorax following thoracotomy is unlikely to settle and early re-exploration is usually necessary. If the site of leak cannot be identified the thoracic duct can be ligated where it passes through the aortic hiatus.

19

A 69-year-old man is one week post coronary artery bypass graft using the left internal mammary artery as the graft. Postoperatively he has reduced chest movements on the left and on chest radiograph he has a raised left hemi-diaphragm.

Diaphragmatic paresis
Diaphragmatic paresis results from damage to the phrenic nerve. This may occur in about 2% of cardiothoracic procedures. The majority recover over six months to two years. About 20% are permanent.

The condition can also occur in viral illness (Guillain-Barré syndrome), vasculitis and diabetes. The phrenic nerve may also be affected by neurological disease, such as poliomyelitis or herpes zoster (shingles).

About 33% are caused by intra-thoracic tumours. These include bronchogenic carcinomas, lymphomas, germ cell tumours and thymomas.

20

A 68-year-old man is one week post coronary artery bypass grafting. He is pyrexial and complains of rigors. The chest radiograph reveals a widening of the mediastinum, with a fluid level seen in the posterior mediastinum.

Mediastinitis
Acute mediastinitis most frequently occurs following cardiac surgery, but may also result from penetrating trauma or rupture of the oesophagus. With a midline sternotomy it is often associated with sternal infection that requires debridement. There is usually also a pleural effusion on one or both sides. This may then develop into an empyema. If neglected the infection may spread into the neck. The trachea may then be displaced anteriorly. This can cause fatal laryngeal obstruction. This patient requires a thoracotomy, drainage of the mediastinum and broad spectrum antibiotics.

21

A 42-year-old woman with bronchiectasis has developed an empyema,which has failed to resolve with antibiotics and guided needle aspiration. A contrast-enhanced CT scan shows a multiloculated empyema with minimally thickened parietal pleura.

Thoracoscopy
Thoracotomy used to be the norm for chronic infection, where there is radiological evidence of gross pleural thickening and multiloculation, or when initial measures fail to achieve rapid resolution. Most patients are now treated thoracoscopically. Surgical treatment requires removal of the fibrous cortex (decortication) allowing re-expansion of the underlying lung.

22

A 51-year-old woman suffers with recurrent pleural effusions secondary to rheumatoid arthritis.

Pleurodesis
Pleurodesis is the obliteration of the pleural space. This procedure may prevent recurrence of pneumothorax, haemothorax, effusion or chylothorax. A variety of sclerosants have been used including blood, tetracycline, bleomycin and talcum powder. Surgical pleurodesis may be achieved at thoracotomy by stripping the parietal pleura.

23

A 33-year-old woman has developed a right pleural effusion following a laparoscopic cholecystectomy. The effusion does not appear to be loculated on chest radiograph or ultrasound. Simple needle aspiration revealed pus.

Guided intercostal drainage
Simple needle aspiration is only effective for non-loculated pleural effusions. Where there is pus in the pleural space an intercostal drain should be inserted, with strict asceptic technique, under radiological guidance.

24

A 62-year-old man develops low grade pyrexia on the fifth postoperative day following a left total hip replacement. On examination the wound appears healthy, chest and abdominal examination are normal. There is no significant growth on culture of the mid-stream urine sample.

Deep vein thrombosis can present with a spectrum of symptoms ranging from asyptomatic to limb-threatening phlegmasia cerulea dolens. They most frequently occur between the 5-10th postoperative days. Operations causing immobility (for example, pelvic and orthopaedic procedures), malignancy and the oral contraceptives predispose to thrombosis. Signs include swelling of the leg, dilatation of the superficial veins, warmth, tenderness and often associated with a low grade pyrexia. Initial management with low molecular weight heparin is aimed at preventing thrombus propagation and preventing pulmonary embolism. Following initial management the patient will require three months of warfarin.

25

A 66-year-old woman develops a fever on the tenth postoperative day following an anterior resection for a midrectal tumour. On abdominal examination there is generalised tenderness with percussion rebound.

Anastomotic dehiscence
Anastomotic dehiscence or leak is most frequently caused by poor knotting, suturing or too much tension. They may also result in diabetic patients or from tissue ischaemia (poor perfusion). Patients may develop insidious signs (due to the formation of an intra-abdominal abscess) or with frank peritonitis (tachycardia, hypotension and pyrexia).

26

A 58-year-old man develops a low grade pyrexia on the second postoperative day following a total gastrectomy. He is tachypnoeic with decreased air entry bilaterally on chest examination.

Atelectasis
Atelectasis results from small plugs of mucus blocking small airways causing a localised collapse. Normally the patient is able to expectorate these small plugs by coughing. Following surgery they may not be able to cough due to excessive sedation, or inadequate analgesia. The small plugs of mucus are easily cleared by physiotherapy. Failure to clear atelecasis can result in infection and pneumonia. Atelectasis presents at 24-48 hours following surgery with tachypnoea, hypoxia and low grade pyrexia.

27

Twelve hours following surgery the patient becomes hypotensive (BP 95/55 mmHg) and tachycardic (120 beats per min).

Hypovolaemic shock
Causes for postoperative haemorrhage include:

obesity
anticoagulant therapy
long term steroid therapy, and
old age (increased capillary fragility).
Haemorrhage within 24 hours of surgery is classified as primary haemorrhage and usually results from a technical problem of haemostasis. Secondary haemorrhage usually occurs at five to 10 days following surgery and is due to local infection, sloughing of a clot or erosion of a ligature.

Fluid requirements greater than expected should alert the surgeon to the possibility of ongoing bleeding. Re-exploration is necessary if the patient does not respond to fluid replacement.

28

On the tenth postoperative day following major abdominal surgery the patient is found collapsed in the ward. On examination he is tachycardic, tachypnoeic and peripherally cyanosed.

Pulmonary embolism
The effects of pulmonary embolism range from symptomless to fatal. Small emboli wedged in the peripheral lung may cause pleuritic chest pain. Larger emboli may obstruct a large part of the pulmonary circulation resulting in central chest pain and circulatory collapse. Massive pulmonary emboli may prevent the right heart from emptying and is therefore rapidly fatal.

The ECG may show:

sinus tachycardia
atrial fibrillation
T wave inversion, or
right bundle branch block.
Pulmonary embolism is treated with intravenous or subcutaneous low molecular weight heparin followed by warfarinisation for three months. Wound breakdown may result in superficial wound dehiscence, full thickness dehiscence or incisional hernia. Predisposing factors are either general (respiratory disease, obesity, jaundice, nutritional deficiencies, steroid therapy, malignancy) or local (wound infection, ischaemia, poor surgical technique).

29

On the ninth postoperative day following an elective abdominal aortic aneurysm repair the patient develops abdominal pain and discharge from the abdominal wound.

Full thickness wound dehiscence
A full thickness wound infection is usually preceded by prolonged ileus, low-grade pyrexia and bloodstained serous discharge. Mortality from a full thickness discharge is high. Early identification should be followed by resuscitation, re-exploration and peritoneal lavage followed by an adequate repair.

30

On the third postoperative day following an elective laparoscopic cholecystectomy, the patient develops a swinging fever, and a right upper quadrant mass.

Subhepatic abscess
A subhepatic abscess may develop following cholecystectomy due to a collection of blood or bile becoming infected. Pus may collect in the right subphrenic, right subhepatic or left subhepatic space. Escherichia coli and Bacteroides are the most frequent organisms isolated from blood cultures or aspirated pus. Subhepatic abscesses are usually associated with a swinging pyrexia and upper abdominal pain. Subhepatic abscesses may be treated with CT or ultrasound guided aspiration. Surgical drainage is required if guided aspiration fails to drain all pus, loculated abscess or failure of symptoms to resolve.

31


A 38-year-old woman underwent an open cholecystectomy and exploration of the common bile duct. The day following surgery she complains of severe upper abdominal pain. On examination she is tachycardic and hypotensive.

Acute pancreatitis
Acute pancreatitis is a serious complication of bile duct exploration both open and endoscopically (ERCP). The danger of acute pancreatitis can be minimised by avoiding blunt instrumentation of the lower bile duct and sphincter of Oddi. If suspected a serum amylase should be performed and stratification by the Glasgow-Imrie criteria if elevated.
Following laparoscopic cholecystectomy the patient has a persistently large bilious output from the drain. At ERCP no contrast is seen coming from the cystic duct remnant.

32


Following laparoscopic cholecystectomy the patient has a persistently large bilious output from the drain. At ERCP no contrast is seen coming from the cystic duct remnant.

Accessory duct leakage
An important anatomical variation to be aware of when performing a cholecystectomy is the presence of an accessory bile duct (duct of Luschka), which runs in the gallbladder fossa. This duct is present in 12-50% of individuals and drains a variable portion of the right liver. When dissecting the gallbladder from its fossa a thorough search should be made for an accessory duct. If identified at the time of operation it is clipped in a similar fashion to the cystic duct.

33

A 57-year-old woman with ovarian malignancy has experienced recurrent pulmonary embolism from a lower limb source despite warfarinisation.

Caval filter

The use of caval (umbrella) filters remains controversial.

Anticoagulation remains the most effective treatment to prevent pulmonary embolism (PE). However, in a minority of patients, anticoagulation will fail or will result in complications.

Other indications for caval filters include

PE in the presence of severe right heart failure and pulmonary hypertension
Extensive embolic occlusion of the pulmonary circulation
During thrombolysis of a pulmonary embolism (as 20% will embolise during therapy).
Insertion of a caval filter is performed by percutaneously cannulating the internal jugular vein and deployment of the filter in the inferior vena cava.

Pulmonary embolism causing a severe drop in cardiac output requires either pulmonary artery thrombolysis or catheter embolectomy. Thrombolysis is contraindicated in the post-operative period.

34

A 45-year-old woman developed an extensive iliofemoral deep vein thrombosis has developed acute shortness of breath, hypotension and tachycardia three days following a total abdominal hysterectomy.

Catheter embolectomy

Catheter embolectomy is performed on cardiac bypass, involves a median sternotomy and clamping of the aorta, pulmonary trunk, superior and inferior vena cavas.

Endovascular embolectomy via a transfemoral approach and caval filter is practised in some expert centres.

35

A 52-year-old woman with known protein C deficiency presents with an acutely swollen, cyanosed painful right lower limb. A venous duplex confirms an extensive iliofemoral DVT. Symptoms do not resolve with heparin therapy.

Thrombolysis

This woman has developed phlegmasia caerula dolens (extension of thrombosis to the venular and capillary level - acute arterial ischaemia). This condition occurs most frequently in hypercoagulable states.

Patients require aggressive resuscitation if hypovolaemic shock has developed. If the clinical condition has not improved in 12-24 hours with limb elevation and IV heparin then thrombectomy or thrombolysis should be attempted.

Thrombolysis is delivered via a catheter inserted in the contralateral femoral vein and advanced into the thrombus. A temporary caval filter is usually passed at the same time.

36

A 23-year-old woman suffers a spinal cord injury in a road traffic accident. Neurological examination reveals she has no sensation below her umbilicus.
Which is the sensory level of this injury?
(Please select 1 option)
T1
T4
T10
L1
L3

T10
When considering dermatones of the trunk the following list is useful to remember:

T2 - medial arm, axilla, thorax
T4 - nipple
T10 - umbilicus
L1 - suprapubic & inguinal regions, penis and anterior scrotum.

37

A 12-year-old boy is riding his bike. He is forced to brake suddenly and lands on his perineum on the crossbar of his bike.
When he attempts to urinate after the injury he develops marked swelling of the scrotum.
Which structure is this boy most likely to have injured?
(Please select 1 option)
Bladder
Prostatic urethra
Spongy urethra
Testicle
Testicular artery

Spongy urethra
Rupture of the spongy urethra results in urine passing into the superficial perineal pouch.

The attachments of the perineal fascia mean that rupture of the spongy urethra may result in swelling of the scrotum, penis and subcutaneously into the lower abdominal wall.

38

A 31-year-old hairdresser presents to her general practitioner with a four month history of fever and chills, abdominal discomfort and diarrhoea. She also states that she passes air occasionally when she attempts to pass urine.
On examination, she is tender over the right iliac fossa. Per rectal examination is unremarkable but a few small ulcers are noticed around the perianal region.
Colonoscopy reveals skip lesions of linear ulcers and transverse fissures giving cobblestone appearance of the mucosa.
CT scan reveals an enterovesical fistula.
Which of the following is the correct diagnosis?
(Please select 1 option)
Carcinoma of the caecum
Carcinoma of the sigmoid colon
Crohn’s disease
Typhoid gastroenteritis
Ulcerative colitis

Crohn's disease is an auto-immune condition characterised by transmural inflammation of the gastrointestinal tract. This can affect any part of the tract from mouth to the anus, although it frequently affects the terminal ileum.

The common clinical presentations include

Loss of appetite
Loss of weight
Fever
Abdominal pain, and
Altered bowel habits such as constipation and diarrhoea, the latter being more common.
Crohn's disease is characterised by skip lesions (patchy areas of inflammation) and by deep serpiginous ulcers. The disease may manifest with the formation perianal ulcers and fistulas.

This patient has developed an enterovesical fistula which is causing her to pass air when she attempts to pass urine.

39

A 53-year-old lady who is a keen rambler is out walking and twists her ankle. She is unable to weight bear and is brought to her local Emergency department.
An x ray is taken which shows a fracture of the distal fibula around the ankle mortice, with movement of the talus.
Which classification system is commonly used to classify this type of fracture?
(Please select 1 option)
Evans classification
Garden classification
Gartland classification
Neer classification
Weber classification

Weber classification This is the correct answerThis is the correct answer
Weber's classification is based on the level of the fibular fracture.

A type A fracture occurs below the syndesmosis of the tibia and fibula.
A type B fracture is at the level of the syndesmosis.
A type C fracture is above the syndesmosis.
The others are

Gartland's classification is related to supracondylar fractures of the humerus.
Neer's classification is for proximal humeral fractures.
Garden's classification is for proximal (intracapsular) fractures of the hip.
Evans' classification is for inter-trochanteric (extracapsular) fractures of the hip.

40

52-year-old male electrician sustained full thickness burns to all the fingers of his dominant hand after grabbing a hot welding rod.

Referral to the specialised burns unit
This man has burnt his fingers and needs specialist care to prevent complications and complete rehabilitation.

41


A 49-year-old female is admitted with 40% burns sustained in a camping accident with a kerosene lamp.

Intravenous fluids
The woman has 40% burns. In general burns greater than 15% require intravenous fluids.

42

A 33-year-old male is admitted to the Emergency department after a fire accident with petrol in his garage. He is conscious, breathless but vital signs are fine; however he has singed his nostrils and has pain in his throat.

Anaethetise and intubate
The issue in the man involved in a garage fire is the potential major airway damage. His symptoms and signs indicate upper airway and probable lung injury. Although there is no immediate airway problem, this patient may benefit from anaesthesia and intubation to protect his airway and reduce the risk of pulmonary complications.

Burns management is dictated by the extent and degree of burns. The extent of burns in an adult is calculated by the 'rule of nines' and the degree by the depth of the burn - partial thickness or full thickness.

Inhalation injury greatly increases the mortality of burn patients. Indicators of such injury are:

Burns sustained in a closed space
Facial or oropharyngeal burns
Singed nasal hair, and
Carbonaceous sputum.
Such patients may benefit from early prophylactic intubation and ventilation.

43

A 23-year-old female presents with discharge of small bowel effluent from her abdominal wound following a small bowel (mid-jejunum) resection for Crohn’s disease.

High output fistula
A postoperative enterocutaneous fistula is a communication between the bowel and the body wall.

The quantity of discharge is related to the site of fistula with high output more than 500 ml/day (proximal small bowel) and low output less than 500 mls/day (distal small bowel).


44

A 68-year-old female has presented with recurrent urinary tract infections. She also reports ‘fizzing’ on passing urine and debris in the urine.

Vesicoenteric fistula
Postoperative fistulas usually close spontaneously with conservative measures provided there is no down-stream obstruction.

Diverticular disease is the commonest cause of vesicocolic fistula due to an inflamed sigmoid diverticulum abutting the bladder.

The typical symptoms are of urinary tract infection, pneumaturia and occasional debris in the urine. The treatment of choice is resection of the affected portion of the colon with anastomosis and closure of the opening in the bladder.

45


A 32-year-old male has presented with persistent faeculent discharge onto his under clothes.

Anal fistula
Anal fistulae result from perianal abscesses. The abscess may rupture onto skin or through the external anal sphincter back into the bowel producing a fistulo in ano. Fistulae are treated by lying them open, that is, by passing a probe through them and then cutting down on to the probe.

46

In tension pneumothorax, which one of the following signs is present?
(Please select 1 option)
Collapsed neck veins
Bradycardia
Hyper-resonance to percussion on the affected side
Hypocapnia
Tracheal deviation to the ipsilateral side

Hyper-resonance to percussion on the affected side

In a tension pneumothorax air accumulates under pressure in the pleural space leading to shift of the mediastinum to the contralateral side.

The raised intrathoracic pressure affects all chambers of the heart. Venous return is impaired and the neck veins may distend. Cardiac output is reduced. This causes hypotension and a tachycardia.

The classical clinical signs are:

Reduced breath sounds and hyper-resonance to percussion on the affected side
Tracheal shift to the contralateral side
Distended neck veins
This is a clinical diagnosis. Do not take a chest x ray.

The treatment is immediate needle thoracocentesis followed by insertion of a chest drain.

47

Wound healing by secondary intention takes place in which of the following?
(Please select 1 option)
More quickly than healing by first intention
When the wound becomes infected
When the wound does not break apart
When the wound edges are brought together
When there is irreparable skin loss

When the wound becomes infected
Healing by secondary intention occurs when the wound edges are apart.

Angiogenesis and fibroblast proliferation result in the formation of granulation tissue, which contracts to reduce the wound area and allows epithelialisation across its surface to achieve wound closure.

When the wound edges are apposed healing proceeds rapidly to closure and this is known as primary healing.

If there is irreparable skin loss then the process would be very slow and the resultant healed surface is a thin layer of epithelium on scar tissue that may not prove durable in the long-term.

Healing by secondary intention is a slower process due to the formation and contraction of granulation tissue resulting in a slow apposition of the opposing skin appendages.

When the wound is infected it should heal by secondary intention. Attempting to heal the wound by primary measures would leave an underlying infection that would lead to wound breakdown.

48

Which of the following is true regarding intestinal malrotation?
(Please select 1 option)
Is corrected by Pringle's procedure
May be associated with volvulus around a narrow-based mesentery
May be diagnosed if the duodeno-jejunal flexure is to the left of the midline on contrast study
May involve the entire hindgut
Presents most commonly in the second to third year of life

May be associated with volvulus around a narrow-based mesentery

Malrotation is due to failure of normal midgut rotation during embryogenesis.

Volvulus around the narrow based mesentery is potentially fatal.

Two thirds of cases present within the first month of life and bilious vomiting is characteristic. An upper gastrointestinal contrast study is performed (if the baby is well), and if the duodeno-jejunal flexure is positioned to the right of the midline this is extremely suggestive of malrotation.

It is corrected by Ladd's procedure which broadens the base of the mesentery and places the bowel in a non-rotated state (that is, stable and not prone to volvulus).

49

Which of the following is true in a patient who has sustained severe burns?
(Please select 1 option)
Aminoglycoside antibiotics have a longer half life
Bacterial contamination of a wound swab is an indication to start systemic antibiotics
Sepsis is an uncommon cause of death
The burn injury depresses immunity
The level of T suppressor cells is decreased

The burn injury depresses immunity

Thermal injury does depress immunity, but the exact mechanisms have not been fully explained. However, diminished neutrophil chemotaxis, impaired phagocytic activity and increased numbers of T suppressor cells (not decreased) have all been demonstrated.

Sepsis and multiple organ failure (initiated by bacterial translocation from the gut, infection and the release of mediators from dead tissue) are the leading causes of death.

Systemic antibiotics should only be prescribed if a burn wound infection is confirmed (by blood cultures, and examination of wound biopsies). Bacterial contamination of a burn wound is generally not an indication to administer systemic antibiotics.

Aminoglycoside antibiotics have shortened half lives (not lengthened), due to increased clearance and ongoing fluid losses.

50

A 30-year-old male has sustained 30% (body surface area) burns to his upper limbs and trunk in a house fire. He is breathing spontaneously, has palpable peripheral pulses but is unconscious (barely responds to stimulation).
Which one of the following conditions is not likely to explain his unresponsiveness?
(Please select 1 option)
Alcohol intoxication
An associated head injury
Drug overdose
Fluid loss from the burn and subsequent hypovolaemia
Hypoxia

Fluid loss from the burn and subsequent hypovolaemia

Whenever the burn injury is extensive (that is, more than15-20% of the body surface area [BSA] in adult patients) the patient will require intravenous fluid resuscitation. However, a young healthy patient with a 30% BSA burn is unlikely to be hypovolaemic resulting in unconsciousness.

Several fluid resuscitation formulae are known, and are used to calculate the volume of fluid required in the first 24 hours following a burn.

With the Parkland formula the normal crystalloid requirements for the first 24 hours are around 4 ml per % BSA burned per kg body weight. The rate of fluid resuscitation is subsequently adjusted to maintain a urine output of between 0.5 and 1.0 ml/kg per hour.

The possibility of associated injuries, inhalation burns, drug overdoses or alcohol intoxication should always be kept in mind. Alcohol and drug intoxication are both potential causes of unconsciousness.

Concomitant mechanical trauma is not infrequently seen in burn victims, and so should always be looked for. An associated head injury could easily account for the reduced conscious level.

If the patient has been exposed to fire or smoke in an enclosed space, for example, in a house fire, then the possibility of inhalation injury, including carbon monoxide (not dioxide) and cyanide poisoning should be considered.

A high concentration of carboxyhaemoglobin can cause unconsciousness, convulsions and coma. The resulting hypoxia should be treated with high 100% oxygen.

51

Which of the following is true regarding asbestos exposure?
(Please select 1 option)
Causes mesothelioma 10-12 years after initial exposure
Is rarely associated with a productive cough
May present with bowel obstruction with prolonged exposure
Produces increased radiolucency on plain chest radiography
Usually results in asbestosis if exposed for six years or more

May present with bowel obstruction with prolonged exposure

Asbestosis is chronic lung disease caused by long term exposure to asbestos. The disease usually occurs in people who have had exposure to asbestos for 15 years or more. Prolonged exposure increases the risk of lung cancer, mesothelioma and non-malignant lung and pleural disorders.

Mesothelioma is a cancer affecting the lining pleura and the peritoneum, and the majority of mesotheliomas are caused by exposure to asbestos. They are usually diagnosed 30 years or more after the initial exposure to asbestos. It is more common in men than in women.

Patients present with

Dyspnoea
Persistent and productive cough
Tightness in the chest
Chest pain
Loss of appetite
Loss of weight.
Plain chest radiography may reveal extensive scarring in the lung and obliteration of the costophrenic angle due to pleural effusion.

Patients who have developed peritoneal mesothelioma may present with

Abdominal pain
Ascites
Nausea or vomiting
Weight loss
Signs and symptoms of bowel obstruction.

52

Which of the following is true of toxic shock syndrome?
(Please select 1 option)
Can lead to a rise in haemoglobin
Cerebral oedema is a recognised early complication
Commonly occurs when burns affected >15-20% total body surface area
Is associated with a diffuse macular rash and diarrhoea
Is caused by Streptococcus faecalis

Is associated with a diffuse macular rash and diarrhoea

This alarming syndrome could result even from small scalds in young children.

The onset is sudden with

Vomiting
Diarrhoea
Temperature greater than 40 degrees
Diffuse macular rash which later desquamates
Tachynoea and
Oliguria.
These signs usually develop on the third or fourth day after sustaining the scald/burn and are associated with a drop in haemoglobin and white cell count.

It is caused due to a toxin produced by Staphylococcus aureus phage type 29/52. Late complications include irritability, cerebral oedema, convulsions and coma.

Treatment should be prompt with control of temperature by vasodilatation, reduction of cerebral oedema, if necessary by hyperventilation, and the administration of whole blood, immunoglobulins and antibiotics.

53

In the management of burns in a specialised burns unit, which of the following is correct?
(Please select 1 option)
Autografting (during the first surgery) is always possible in burns involving up to 60% total body surface area
Chemical burns may cause more skin damage (in terms of burn depth) than scalds
In a fit 34-year-old male with full thickness burns involving 55% total body surface area, late debridement and grafting is recommended
Meshed skin grafts achieve superior cosmetic results compared to unmeshed skin grafts
Skin grafting is absolutely contraindicated in the presence of Enterococcus faecalis in the wound

Chemical burns may cause more skin damage (in
terms of burn depth) than scalds

In a patient with full thickness burns, early excision of all burned skin is recommended. Grafting, if not possible, could be done at a later time.

Enterococcus faecalis is a common skin contaminant in burns and its colonisation does not preclude successful skin grafting.

Unmeshed skin grafts achieve superior cosmetic results compared to meshed skin grafts. Meshed grafts are recommended in areas where continued oozing is anticipated since meshing prevents development of underlying haematoma.

Autografting is not possible in burns involving more than 40% total body surface area without reusing the donor site again in the next 7-10 days.

Chemicals burns cause extensive skin damage. Unlike scalds, chemical burns that appear superficial at presentation soon progress to full thickness (deep dermal).

54

In the initial management of burns in the Emergency department, which of the following is correct?
(Please select 1 option)
A full-thickness burn is painful, red and blistered
Cold water should be applied to extensive burns
In children, intravenous fluids are indicated only if the burn is >20% of total body surface area
Intravenous access should be secured through burned skin only if no other access is available
The adult patient requires transfer to the burns unit only when the burn is >40% of total body surface area

Intravenous access should be secured through burned skin only if no other access is available

Partial thickness burns are painful, red and blistered. Full-thickness burns are painless and white/grey.

All adults with greater than 20% burns, and children and elderly with greater than 10% burns should be transferred to the burns unit as soon as they are stabilised.

Intravenous access should be secured by any means, even through burned skin. Intravenous cutdown in the cubital fossae or on the long saphenous vein (either in front of the medial malleolus or the groin) may be required if percutaneous intravenous access cannot be obtained.

In children less than 6-years-old, if intravenous access is not obtained, access should be sought through an intraosseous approach (commonly in the tibia).

Applying cold water to extensive burns can intensify shock.

All burned areas should be covered with sterile, warm, non-adherent dressing (taking care to prevent hypothermia) or cling film before the patient is transferred to the burns unit.

Intravenous fluids are essential in burns involving more than 10% total body surface area in children and more than 15% total body surface area in adults.

55

Which of the following statements regarding soft tissue coverage and tissue transfer is true?
(Please select 1 option)
Composite grafts maintain their own blood supply
Free flaps cannot survive based on a pedicle less than 3-mm in diameter
The donor site of a full-thickness skin graft is usually left to heal by secondary intention
The 'take' of a skin graft is independent on the vascularity of the recipient site
V-Y plasty (flap) is a form of advancement flap

V-Y plasty (flap) is a form of advancement flap

Composite grafts, like skin grafts, depend on blood supply from the recipient site. Arteries up to 1 mm in diameter can be successfully anastamosed using microsurgical techniques.

Local skin flaps are of two types: flaps that rotate about a pivot point (rotation, transposition, and interpolation flaps) and advancement flaps (single-pedicle advancement, Y-V advancement, V-Y advancement, and bipedicle advancement flaps).

The donor site of a split or partial thickness skin graft is left to heal by secondary intention. On the contrary, the donor site of a full-thickness graft requires closure.

The success of skin grafting, or 'take', depends on the ability of the graft to receive nutrients and subsequently vascular ingrowth from the recipient site.