Share your insights

Help us by sharing what content you've recieved in your exams

Post-operative complications

General complications


  • Anaesthetic complications (e.g. arrhythmia, hypo-/hypertension, hyperthermia, breathing problems, MI/stroke, allergy, teeth/lip/tongue damage)
  • Haemorrhage – often not obvious externally (monitor drains, observations, FBC/haematocrit)


  • Fluid depletion
  • Electrolyte imbalances
  • Local infection (wound/surgical site) or systemic infection (chest/UTI/sepsis)
  • Fluid collections
  • Atelectasis
  • DVT/PE
  • Wound break down
  • Anastomotic break down
  • Bed sores

Specific complications

General surgery

OperationSpecific complications
GastrectomyDumping syndrome
Anastomotic ulcer
Peptic ulcers/gastric cancer
Small intestinal bacterial overgrowth
Abdominal fullness/gas bloating
Small and large bowel operationsIleus
Anastomotic leaks (typically present 5-10 days post-operatively but can be up to 21 days)
Stoma retraction
Intra-abdominal collections
Pre-sacral plexus damage
Adhesions/intestinal obstruction
Damage to other local structures, e.g. kidneys, ureters, bladder
Cholecystectomy Common bile duct injury/bile leak
BiliaryCommon bile duct injury/bile leak
Common bile duct stricture
Anastomotic leak
Bleeding into biliary tree (jaundice)


OperationSpecific complications
Grafts/stents/bypass procedures Failure of graft, haemorrhage/haematoma, infection, re-thrombosis, limb or organ ischaemia
Arteriovenous fistula 
Cholesterol embolism (e.g. trash foot)
Arteriopaths are at high risk of: ACS, stroke, PE
Contrast complications, e.g. anaphylaxis, renal injury


OperationSpecific complications
ThyroidectomyAirway obstruction secondary to haemorrhage – requires urgent opening of thyroidectomy wound
Hypocalcaemia (damage to parathyroid glands)
Recurrent laryngeal nerve damage
ParotidectomyFacial nerve damage

Trauma and orthopaedic

OperationSpecific complications
Any orthopaedic operationInfection of prosthesis
Loss of position/failure of fixation
Non-union, malunion, delayed union
Neurovascular injury
Compartment syndrome
Total hip arthroplastySciatic nerve damage, dislocation, leg length difference, loosening, wear, need for revision surgery


OperationSpecific complications
Cystoscopy/transurethral resection of the prostate  High risk of UTI
Transurethral resection of the prostate syndrome (absorption of irrigation fluid causing hyponatraemia)
Impotence/retrograde ejaculation
External sphincter damage (incontinence)
Urethral stricture

Other operations

OperationSpecific complications
Endovascular surgeryRetroperitoneal haemorrhage
Lymph node dissection (e.g. axillary nodes in breast cancer surgery)Lymphoedema
Neck dissection (e.g. branchial cyst excision)Cranial nerve damage (11, 12)

Assessing an unwell post-operative patient

General tips

  • Use an ABCDE approach (see notes on ABCDE management)
  • Consider the operation, pre-operative fitness and post-operative progress
  • Think about specific risks associated with the operation 
  • Special attention should be given to operative site, newly placed drains and their contents

NB: pain, operative stress and inflammation may be confounding factors when assessing a patient with deranged physiological parameters, but it is important to exclude more serious underlying causes.


  • Assess in conjunction with other physiological parameters (heart rate, blood pressure, respiratory rate)
  • Sepsis is the most common cause but operative intervention causes an inflammatory response in itself and may result in low grade pyrexia
  • Surgical patients are at particular risk of chest infections due to suboptimal ventilation causing basal atelectasis. But consider other sources of sepsis, such as UTIs.
  • The timing of the pyrexia may give a clue to the underlying diagnosis:


Causes of post-operative fever (5 W’s)

Category Days post-op Causes
Wind <2 Atelectasis, pneumonia
Water 2-4 UTI
Wound 5-7 Wound infection, infected post-operative collections
Walking 8-10 Venous thromboembolism
Wonder drugs Any time Transfusion/drug reactions (e.g. serotonin syndrome)


  • There should be two aims in assessing a patient with hypotension, identifying a cause and assessing for organ dysfunction
  • Causes may include:
    • Decreased intravascular volume: long operations and evaporative fluid losses, third space fluid losses, haemorrhage and poor oral intake should all be considered
    • Pump failure (cardiogenic shock): surgical stress increases the risk of MI (typically occur 48 hours post-operatively). Fluid overload and heart failure should also be considered.
    • Sepsis and anaphylaxis
    • Sympathetic shock: patients with epidural analgesia and a high block (T5 and above) can lose sympathetic outflow causing vasodilation and cardiogenic shock – assess epidural blocks using cold sprays. Spinal anaesthetics in elderly patients may contribute to loss of sympathetic tone and hypotension.
  • Clinical signs of poor perfusion include: delayed capillary refill time, cold peripheries, tachycardia
  • Specific evidence of organ dysfunction should be sought: ABG for lactate, assessment of urine output (should be >0.5ml/kg/hour), confusion

Respiratory difficulties

  • Respiratory problems are common in surgical patients
    • Respiratory tract infections: post-operative patients are high-risk due to immobility, poor inspiratory effort due to pain and basal atelectasis
    • Pulmonary embolism: both surgery and underlying pathologies such as cancers and sepsis increase VTE risk
    • Pulmonary oedema: large fluid shifts, hypoalbuminaemia and cardiac dysfunction predispose to this
  • Assessment of respiratory difficulties should include: assessment of fluid state (clinical hydration status, JVP, urine output), assessment of calves for DVTs, investigation for infection (e.g. bloods, CXR) and ABG

Low urine output

  • An acceptable urine output as a rule is considered to be >0.5ml/kg/hour
  • Consider the causes of acute kidney injury
    • Pre-renal: most common; usually due to volume depletion but may also be caused by inadequate cardiac output
    • Renal: may be secondary to nephrotoxic drugs (e.g. aminoglycosides, metformin)
    • Post-renal: may be due to prostatic hypertrophy or raised intra-abdominal pressures causing compression of ureters
  • An assessment of the patient with low urine output should include a fluid status assessment (with care to look at fluid losses from drains and 3rd space losses into the bowel or tissues), a medicines review, and a catheter examination/bladder scan

Test yourself with some questions

You are asked to see a patient after a thyroidectomy, complaining of muscle spasm. The nurse noted their hand muscles spasm when the blood pressure is checked. What is this sign called? What is the cause and initial management?

  • Trousseau Sign = carpopedal spasm induced by inflation of blood pressure cuff
  • Cause is hypocalcaemia
  • Initial management is to check calcium, PTH, vitamin D
  • Initial management = replace calcium intravenously (learn more about electrolyte correction here)

An 84 year old with a neck of femur femur fracture is day one post-THR. She has palpitations and an ECG has been undertaken (link below). What is the diagnosis and initial management?

  • ECG shows atrial fibrillation
  • Initial management
    • Clinical examination and assessment of fluid status
    • Check bloods, including all electrolytes, thyroid function
    • Consider rate control with bisoprolol or digoxin
    • IV fluids if hypovolaemic, IV antibiotics if concerned about infection
    • Anticoagulation may need to be considered but not in the immediate post-operative period due to high bleeding risk (unless there is a concern about VTE)

Link to ECG here

Now try some OSCE stations

  1. Post-operative breathlessness
  2. Post-operative complication
  3. Find lots more stations here!

No comments yet 😉

Leave a Reply