Post-operative complications

Question 1

Delirium

Answer 1

Acute confusional state, characterised by a disturbed consciousness and reduced cognitive function

Question 2

Types of delirium

Answer 2

Hypoactive delirium – marked by lethargy and reduced motor activity
Hyperactive delirium – marked by agitation and increased motor activity
Mixed agitation – marked by fluctuations throughout a day

Question 3

Delirium risk factors

Answer 3

Age > 65 years
Multiple co-morbidities
Underlying dementia
Renal impairment
Male gender
Sensory impairment (hearing/visual)

Question 4

Delirium causes

Answer 4

Hypoxia
Infection
Drug-induced or drug withdrawal
Dehydration or pain
Constipation or urinary retention
Electrolyte abnormalities

Question 5

Delirium investigations

Answer 5

Bloods – FBC, U&Es, Ca2+, TFTs, glucose
Blood cultures and/or wound swabs
Urinalysis and/or CXR
CT head

Question 6

Delirium management

Answer 6

Any identified cause should be treated appropriately
Should be nursed in an appropriate environment & regular sleeping patterns promoted
Preventing worsening – oral fluid intake, provide analgesia & monitor bowels
Sedatives should be used sparingly – haloperidol is 1st line

Question 7

Haemorrhage types

Answer 7

Primary – bleeding that occurs within the intra-operative period
Reactive – occurs within 24 hours of operation
Secondary – occurs 7-10 days post-operatively

Question 8

Haemorrhage clinical features

Answer 8

Clinical features of haemorrhagic shock: tachycardia, dizziness, agitation, raised RR, decreased urine output
Examination – thorough exposure looking for bleeding, followed by systematic palpation of the surgical area looking for swelling, discolouration, disproportionate tenderness & any peritonism

Question 9

Haemorrhage management

Answer 9

A to E approach – ensure adequate IV access and rapid fluid resus
Apply direct pressure to bleeding site if visible & urgent senior surgical review
Urgent blood transfusion, major haemorrhage protocol activated as necessary
May be appropriate to re-operate on patient for further haemostasis

Question 10

Post-operative nausea and vomiting (PONV) risk factors

Answer 10

Patient factors – female, age, previous PONV, use of opioid analgesia, non-smoker
Surgical factors – intra-abdominal laparoscopic surgery, prolonged operative time, poor pain control post-operatively
Anaesthetic factors – opiate analgesia, inhalational agents, prolonged anaesthetic times, intraoperative dehydration, overuse of bag & mask ventilation

Question 11

PONV pathophysiology

Answer 11

Two areas in the nervous system that play key role in the control of nausea and vomiting – vomiting centre & chemoreceptor trigger zone
Vomiting centre receives input from the chemoreceptor trigger zone, GI tract, vestibular system & higher cortical structures -> result in nausea
If stimuli are sufficient, acts on the diaphragm, stomach & abdominal musculature to initiate vomiting

Question 12

PONV management

Answer 12

Prophylactic – anaesthetic measures, prophylactic antiemetic therapy, dexamethasone at induction
Conservative – adequate fluid hydration, adequate analgesia, consider NGT
Pharmaceutical
1) Patients with impaired gastric emptying/gastric stasis should be trailed on a prokinetic agent, such as metoclopramide (dopamine antagonist) or domperidone (dopamine antagonist), unless bowel obstruction suspected (hyoscine can be used instead)
2) Suspected metabolic/biochemical imbalance causing N&V can be trialled on metoclopramide
3) Opioid-induced N&V typically responds well to ondansetron or cyclizine

Question 13

Consequences of poor pain control

Answer 13

Slower recovery – reluctant to mobilise, in turn resulting in a slower restoration of function and rehabilitation capacity
Patients in pain following abdominal surgery -> not breathe as deeply as they normally would and may not be able to cough to clear secretions resulting in inadequate ventilation and subsequent atelectasis & hospital-acquired pneumonia

Question 14

NSAIDs side effects

Answer 14

I-GRAB
Interactions with other medications (eg. warfarin)
Gastric ulceration
Renal impairment
Asthma sensitivity
Bleeding risk

Question 15

Opiate side effects

Answer 15

Constipation
Nausea
Sedation or confusion
Respiratory depression
Pruritus
Tolerance & dependence

Question 16

Patient controlled analgesia

Answer 16

Involves the use of intravenous pumps that provide a bolus dose of an analgesic when the patient presses a button
Either started in theatre/in wards, when the use of strong oral opiates is inadequate
Can be titrated to give background infusions of analgesia if needed & the analgesic agent used can also vary

Question 17

Post-operative pyrexia aetiology

Answer 17

Most common cause is infection:
Day 1-2: consider a respiratory source
Day 3-5: consider a respiratory/urinary tract source
Day 5-7: consider a surgical site infection or abscess/collection formation
Any day post-operatively: consider infected IV lines/central lines as a source
Other causes: iatrogenic, VTE, secondary to prosthetic implantation, PUO

Question 18

Post-operative pyrexia investigations

Answer 18

Septic screen
Blood tests – FBC, CRP, U&Es, LFTs, clotting
Urine dipstick +/- urine MCS
Cultures – blood, urine, sputum & wound swab
Imaging – CXR, specific cross-sectional imaging

Question 19

Post-operative pyrexia 5 Ws

Answer 19

Wind – chest infection
Water – UTI
Walk – DVT/PE
Wound – deep/superficial infection/collection
What have we done – drugs, lines, transfusion

Question 20

DVT investigations

Answer 20

DVT wells’ score
Score less than/equal to 1 = requires a further D-dimer test to exclude
Score > 1 = DVT is clinically likely and a DVT diagnosis should be confirmed via either a ultrasound scan (more common) or contrast venography

Question 21

DVT management

Answer 21

Direct oral anticoagulants (DOACs) – recommended as first line treatment for DVT
- Direct factor Xa inhibitors: apixaban, rivaroxaban, edoxaban
- Direct thrombin inhibitor: dabigatran
- Dabigatran and edoxaban require initial treatment with LMWH
Should be continued for 3 months in those with a provoked DVT
Proximal DVT and persistent risk factor/high risk of DVT recurrence – may require lifelong anticoagulation

Question 22

PE investigation and management

Answer 22

PE wells’ score should be calculated
Score less than/equal to 4 = PE clinically unlikely, requires a further D-dimer test to exclude
Score greater than 4 = PE clinically likely & diagnosis should be confirmed with a CTPA scan (or V/Q scan in those with poor renal function/pregnancy/allergic to contrast)
Haemodynamically stable PEs – management is same as DVTs
Suspected PEs causing haemodynamic compromise – thrombolysis may be warranted

Question 23

Thromboprophylaxis

Answer 23

All patients undergoing surgery should be offered mechanical prophylaxis unless otherwise contraindicated -> peripheral arterial disease, peripheral oedema or local skin conditions
Mechanical thromboprophylaxis – antiembolic stockings, intermittent pneumatic compression
Pharmacological – LMWH, unless poor renal function, then consider unfractionated heparin

Question 24

Fat embolism syndrome

Answer 24

Rare but serious complication
Occurs with the introduction of fatty tissue into systemic circulation
Most commonly associated with long bone fractures, can also develops following routine orthopaedic procedures

Question 25

Fat embolism syndrome risk factors

Answer 25

Young age Long bone fractures Closed fractures Multiple fractures Conservative management for long bone fractures

Question 26

Fat embolism syndrome clinical features

Answer 26

Worsening SoB, confusion, drowsiness, development of petechial rash Examination – tachypnoeic, tachycardia & hypoxic Low-grade pyrexia Gurd’s criteria used for diagnosis

Question 27

Fat embolism syndrome investigations

Answer 27

Routine bloods – FBC, CRP, U&Es, LFTs and clotting screen ABG Blood film – may show presence of fat globules CXR – diffuse bilateral pulmonary infiltrates CTPA – ground-glass changes with a global distribution

Question 28

Fat embolism syndrome management

Answer 28

Largely supportive, respiratory support is the mainstay of management Prevention – limiting the dispersion of bone marrow into the blood stream, continuous pulse oximetry in patients undergoing IM nailing

Question 29

Anastomotic leaks

Answer 29

A leak of luminal contents from a surgical join

Question 30

Anastomotic leak risk factors

Answer 30

Patient factors – medication, smoking/alcohol excess, diabetes mellitus, obesity/malnutrition Surgical factors – emergency surgery, longer intra-operative time, peritoneal contamination, oesophageal-gastric/rectal anastomosis

Question 31

Anastomotic leak clinical features

Answer 31

Abdominal pain and fever Usually present between 5-7 days post-operatively Examination – pyrexial, tachycardic and/or with signs of peritonism

Question 32

Anastomotic leak investigations

Answer 32

CT scan with contrast of abdomen and pelvis Ensure early resuscitation and senior input Urgent blood tests – FBC, CRP, U&Es, LFTs and clotting screen VBG Repeat group and save

Question 33

Anastomotic leak management

Answer 33

Initial – NBM and start broad spectrum abx cover, IV fluid therapy and insert urinary catheter Definitive – minor leaks usually settle with IV abx, larger ones commonly need to be drained percutaneously Exploratory laparotomy is often required if patient is septic/multiple collections

Question 34

Post-operative constipation aetiology

Answer 34

Physiology – low fibre diet, poor fluid intake, low physical activity Iatrogenic – opioid analgesia, anticonvulsants, iron supplements or antihistamines Pathological – hypercalcaemia, hypothyroidism, neuromuscular disease Functional – painful defecation

Question 35

Post-operative constipation clinical features

Answer 35

Lower abdominal pain, abdominal distension, N&V, decreased appetite Examination – no clinical signs DRE essential to assess the degree of faecal impaction

Question 36

Post-operative constipation management

Answer 36

Conservative measures – adequate hydration, sufficient dietary fibre, treating the underlying cause & encouraging early mobilisation Pharmacological: - Osmotic laxatives: increased the amount of fluid in the bowel thereby softening stool – lactulose, Movicol - Stimulant laxatives: stimulate the bowel to contract thus expelling faeces – senna, picosulphate - Bulk forming laxatives: help stool to retain water thereby softening stool – ispaghula husk - Rectal medications – glycerin suppository, phosphate enema

Question 37

Post-operative ileus

Answer 37

Deceleration or arrest in intestinal motility following surgery Functional bowel obstruction

Question 38

Post-operative ileus risk factors

Answer 38

Patient factors – increased age, electrolyte derangement, neurological disorders, use of anti-cholinergic medication Surgical factors – use of opioid medication, pelvic surgery, extensive intra-operative intestinal handling, peritoneal contamination, intestinal resection

Question 39

Post-operative ileus clinical features

Answer 39

Failure to pass flatus or faeces Sensation of bloating and distension Nausea and vomiting Abdominal distension and absent bowel sounds (mechanical obstruction = tinkling bowel sounds)

Question 40

Post-operative ileus investigations

Answer 40

Initial routine bloods CT scan abdomen and pelvis

Question 41

Post-operative ileus management

Answer 41

NBM, ensuring adequate maintenance IV fluids Daily bloods Encourage mobilisation Reduce opiate analgesia

Question 42

Surgical site infection

Answer 42

Infection that occurs in the incision created by an invasive surgical procedure Superficial – limited to skin and subcutaneous tissue Deep – affecting the fascial and muscular layers Cavity space infection – abdominal or joint cavity

Question 43

Surgical site infection risk factors

Answer 43

Patient factors – increasing age, poor glucose control, obesity, smoking, renal failure, immunosuppression Operation factors – preoperative shaving, length of operation, use of antimicrobial prophylaxis, appropriate skin preparation, appropriate gowning and sterile equipment

Question 44

Surgical site infection clinical features

Answer 44

Typically appear 5 to 7 days post-procedure Spreading erythema Localised pain Pus/discharge from the wound Persistent pyrexia

Question 45

Surgical site infection investigations

Answer 45

Wound swabs taken for culture at the wound site Blood tests for infection markers should be taken, alongside blood cultures Consider cross-section imaging to assess for deep collections

Question 46

Surgical site infection management

Answer 46

Any sutures/clips present should be removed -> allowing for the drainage of any pus & opportunity for wound packing Empirical antibiotics

Question 47

Surgical site infection prevention

Answer 47

Pre-operative phase – prophylactic abx, do not remove hair routinely, patient advice (weight loss, smoking cessation, optimise nutrition, diabetic control) Intraoperative phase – prepare the skin before the incision using an antiseptic preparation, change gloves/gown if contaminated, wound irrigation & use of antibiotic-impregnated sutures Post-operative phase – monitor wounds closely, refer to tissue viability nurse for advice on appropriate dressings

Question 48

AKI

Answer 48

>/= 50% rise in serum creatinine from baseline within last 7 days Increase in serum creatinine by 26.5mmol/L within 48 hours Urine output <0.5mls/kg/hour for more than 6 hours Severity of AKI: - Stage 1 – 1.5-1.9 times the baseline - Stage 2 – 2-2.9 times the baseline - Stage 3 = >3 times the baseline

Question 49

Pre-renal AKI causes

Answer 49

Sepsis Dehydration Haemorrhage Cardiac failure Liver failure Renal artery stenosis

Question 50

Intra-renal AKI causes

Answer 50

Nephrotoxins – NSAIDs, ACEi, antibiotics (aminoglycosides), chemotherapy Parenchymal disease – glomerulonephritides, acute tubulointerstitial nephritis, rhabdomyolysis, haemolytic uraemic syndrome or multiple myeloma

Question 51

Post-renal AKI causes

Answer 51

Ureteric – retroperitoneal fibrosis, bilateral renal stones, tumours Bladder – acute urinary retention, blocked catheter Urethral – prostatic enlargement (BPH/malignancy), renal stones

Question 52

Post-operative AKI investigations

Answer 52

Examine patient & fluid status Bladder scan – evidence of retention, review drug chart Urine dip Initial bloods – U&Es, FBC, CRP, LFTs & Ca2+ Blood gas in severe cases Imaging – USS of the kidneys, ureters & bladder is required in severe cases of AKI

Question 53

Urine dipstick and differentiating causes of AKI

Answer 53

Can aid in differentiating between pre-renal and intrinsic causes of AKI Urine specific gravity & osmolality values will be higher in pre-renal causes, urine Na excretion will be lower due to kidney actively conserving Na and water in pre-renal causes compared to intrinsic causes Any glomerulonephritis will show high levels of blood and protein

Question 54

AKI management

Answer 54

Fluid status – assess patient’s hydration status - Pre-renal: give a fluid bolus & re-assess their fluid status after 10-15 minutes, monitoring the urine output after the bolus, give repeat fluid boluses until the patient is euvolaemic Ongoing monitoring – start monitoring urine output, regular blood tests Drug rationalisation 1) Drugs to be stopped: ACEi/ARBs, NSAIDs, aminoglycoside antibiotics, potassium-sparing diuretics 2) Drugs to be altered or reduced: metformin (risk of lactic acidosis), diuretics, LMWH

Question 55

Post-operative urinary retention

Answer 55

Acute urinary retention – symptomatic inability to completely empty the bladder

Question 56

Post-operative urinary retention clinical features

Answer 56

Little/no urine passed in the post-operative period Sensation of needing to void without being able to micturate Suprapubic mass that is dull to percussion Assessed for any underlying causes – uncontrolled pain constipation, infection, anaesthetic agents (spinal/epidural)

Question 57

Post-operative urinary retention risk factors

Answer 57

Age > 50 years Male gender Previous retention Type of surgery – including pelvic/urological surgery Anaesthetic type – spinal or epidural Neurological/urological co-morbidities Medication (eg. antimuscarinics, alpha agonists, opiates)

Question 58

Post-operative urinary retention assessment

Answer 58

Most important investigations – ultrasonic bladder scan to identify the post-void residual urine volume Check for any potential underlying reversible causes & that there is adequate pain control Check patient has a stable renal function (worsening renal function may suggest a high-pressure retention that is impacting renal function)

Question 59

Post-operative urinary retention management

Answer 59

Conservative management – majority of post-operative urinary retention will resolve spontaneously In those that don’t resolve – any significant retention will require catheterisation, patients can have their catheter removed shortly after (TWOC) For those who fail TWOC & re-enter retention, a new catheter should be inserted & patients for repeat TWOC in 1-2 weeks in the community Make sure to re-assess any potential reversible causes why the patient may have failed their TWOC that can be addressed

Question 60

Post-operative UTI organisms

Answer 60

E. coli Klebsiella sp. Enterobacteur sp. Proteus sp. Pseudomonas sp. Staphylococcus sp.

Question 61

Post-operative UTI risk factors

Answer 61

Age > 60 years Female Significant co-morbidities Catheterisation or recent instrumentation Pregnancy Urinary retention or renal stones

Question 62

Post-operative UTI clinical features

Answer 62

Urinary frequency, urgency & dysuria Examination – mild suprapubic pain & be pyrexial Should be considered in any patient who presents: with delirium, sepsis, in acute urinary retention Assess for features of pyelonephritis – loin pain, renal angle tenderness or pyrexia

Question 63

Sterile pyuria

Answer 63

Presence of an elevated WCC in the urine, however no organisms are identified using standard culture techniques Causes of sterile pyuria – inadequately-treated UTI, STI or renal stones

Question 64

Post-operative UTI investigations

Answer 64

Urine dipstick should be performed initially (despite high risk of contamination seen in elderly population) Urine dipstick is positive or clinical features in keeping with UTI = urine should be sent off for MC&S Routine blood tests may be considered, blood cultures and VBG Bladder scan may be required if patient has potentially entered retention If pyelonephritis is suspected/in cases of recurrent UTIs – a renal US or further definitive imaging may be required to check for obstructive causes

Question 65

Post-operative UTI management

Answer 65

Ensure patient is well hydrated and maintains a satisfactory urine output Definitive management is via antibiotic therapy, classically trimethoprim, nitrofurantoin or co-amoxiclav Adapt abx choice accordingly following MC&S results if poor response, any catheterised patients with a UTI should have their catheter changed prior to starting any antibiotics

Question 66

Post-operative haemorrhage neck surgery

Answer 66

Post-operative thyroidectomy or parathyroidectomy haemorrhage – primary sign is likely to be airway obstruction - Pretracheal fascia of the neck will only distend so far, when bleeding occurs into this space, compression on the venous return results in venous congestion, with subsequent laryngeal oedema leading to eventual asphyxiation Any evidence of respiratory distress/airway compromise in these patients requires an emergency protocol for airway rescue -> removing both the skin clips and deep layer sutures & suction of the haematoma beneath (all done at bedside)

Question 67

Post-operative haemorrhage inferior epigastric artery injury

Answer 67

Inferior epigastric arises from the external iliac artery & runs up the abdominal wall below the rectus muscle -> vulnerable to injury from laparoscopic ports Due to the gas insufflation, this may not be noticed at the time of surgery Particularly after laparoscopic surgery or surgery with a Pfannenstiel incision

Question 68

Post-operative haemorrhage retroperitoneal bleeding post-angiography

Answer 68

Puncture site is often the external iliac artery, above the inguinal ligament -> any bleeding from this artery can track into the retroperitoneum Likely not be a large haematoma around the skin puncture site, because the actual arterial puncture site is hidden by the inguinal ligament Patients will often bleed profusely because tamponading the injury is difficult For any suspected occult retroperitoneal haemorrhage, apply pressure to the puncture site, resus, ensure blood products are made immediately available & call for senior support Cross-sectional imaging to confirm the diagnosis is often required

Question 69

Keloid

Answer 69

Abnormal proliferation of scar tissue which forms at the site of injury, rises above the skin level, projects beyond original wound margins Affects both men and women equally, with the highest incidence occurring between the ages of 20 and 30

Question 70

Keloid pathophysiology

Answer 70

Normal wound healing, there is a balance between new tissue biosynthesis and tissue degradation – achieved through the processes of apoptosis and remodelling of the ECM During keloid formation, there is prolonged inflammatory phase -> contributes to excess fibroblast activity and increased deposition of ECM, resulting in the tissue projecting beyond the original wound margin

Question 71

Keloid risk factors

Answer 71

Ethnicity – most common in black African or Caribbean and Asian populations Age – the highest incidence occurring between 20-30 years Causes – burns carry the highest risk Anatomical site – most commonly occur in scars on the ear lobe, shoulders and sternal notch Previous keloid formation

Question 72

Keloid clinical features

Answer 72

Characteristic visual appearance – keloid scars are raised above the skin around them and can take on the appearance of a dome shape, extending beyond the original wound margin, shiny and hairless Do not normally cause may other symptoms – small proportion of patients experience of pain, itching or burning in the scar tissue

Question 73

Keloid management

Answer 73

Surgical excision is rarely performed – thought to stimulate collagen synthesis -> results in the regrowth of a larger keloid Non-surgical management 1) Intralesional steroids – acting as anti-inflammatory agent that inhibits the fibroblast glucocorticoid receptors, this in turn downregulates the proliferation of fibroblasts and inhibits collagen synthesis 2) Silicone gel – either as a topical gel or as an elastic sheet 3) Radiation therapy – reduces the recurrence of keloids, especially as an adjunct therapy (runs the theoretical risk of inducing malignancy which has limited its potential use)

Question 74

Wound dehiscence

Answer 74

Wound fails to heal, often re-opening a few days after surgery (most common in abdominal surgery) Superficial dehiscence – skin wound alone fails, with the rectus sheath remaining intact - Occurs secondary to local infection, poorly controlled diabetes or poor nutritional status Full thickness dehiscence – rectus sheath fails to heal and bursts, with protrusion of abdominal content - May occur secondarily to raised intra-abdominal pressure, poor surgical technique or if patient is critically unwell

Question 75

Wound dehiscence risk factors

Answer 75

Patient factors – increasing age, male gender, co-morbidities (diabetes), steroids, smoking, obesity/malnutrition Intra-operative factors – emergency surgery, abdominal surgery, length of operation, wound infection, poor surgical technique Post-operative factors – prolonged ventilation, post-operative blood transfusion, poor tissue perfusion, excessive patient coughing, radiotherapy

Question 76

Wound dehiscence clinical features

Answer 76

Visible opening of the wound, healing poorly following the operation Typically happens around 5-7 days post-operatively Classic signs of full thickness dehiscence – new building of the wound and seepage of pink serous or blood-stained fluid from the wound

Question 77

Superficial dehiscence management

Answer 77

Wash wound out with saline and then simple wound care – packing the wound with absorbent ribbon gauze Patient should be advised the wound will now be required to heal by secondary intention & can take several weeks More extensive wounds may be treated with a vacuum-assisted closure device to speed healing

Question 78

Full thickness dehiscence management

Answer 78

Provide suitable analgesia and start broad spectrum IV abx as a priority Cover the wound in saline-soaked gauze and arrange urgent return to theatre for re-closure of the wound For majority of the patients, closure is usually done in theatres with large interrupted sutures, avoiding excessive tension If there is gross abdominal sepsis, necrotising fasciitis of abdominal wall -> can be managed as an open abdomen (using a vacuum dressing) or using a bridging mesh

Question 79

Wound dehiscence prevention

Answer 79

Optimisation of co-morbidities and treating any surgical site infections is key Avoiding heavy lifting and encouraging adequate post-operative nutrition will reduce the risk further