Common Post-Op Complications

Postoperative complications may either be general or specific to the type of surgery undertaken, and should be managed with the patient's history in mind. Common general post-operative complications include post-operative fever, atelactasis, wound infection, embolism and deep vein thrombosis. The highest incidence is between 1 and 3 days after the operation. However, specific complications occur in the following distinct temporal patterns: early postoperative, several days after the operation, throughout the postoperative period, and in the late postoperative period.¹

• Immediate
  • Primary haemorrhage: either starting during surgery or following postoperative increase in blood pressure: replace blood loss and may require return to theatre to re-explore wound.
  • Basal Atelectasis: minor lung collapse
  • Shock: blood loss, acute myocardial infarction, pulmonary embolism or septicaemia.
  • Low urine output: inadequate fluid replacement intra and postoperatively
• Early
  • Acute confusion: exclude dehydration and sepsis
  • Nausea and vomiting: analgesia or anaesthetic related; paralytic ileus
  • Fever (see below)
  • Secondary haemorrhage: often as a result of infection
  • Pneumonia
  • Wound or anastomosis dehiscence
  • DVT
  • Acute Urinary Retention
  • Urinary Tract Infection
  • Postoperative wound infection
  • Bowel obstruction due to fibrinous adhesions
  • Paralytic Ileus
• Late
  • Bowel obstruction due to fibrous adhesions
  • Incisional hernia
  • Persistent sinus
  • Recurrence of reason for surgery, e.g. malignancy

• Days 0 to 2
  • Mild fever (T<38 C) (Common)
  • Tissue damage and necrosis at operation site
  • Haematoma
  • Persistent fever (T> 38 C)
  • Atelectasis: the collapsed lung may become secondarily infected.
  • Specific infections related to the surgery: e.g. biliary infection post biliary surgery, UTI post urological surgery
  • Blood transfusion or drug reaction
• Days 3-5
  • Bronchopneumonia
  • Sepsis
  • Wound infection
  • Drip site infection/ phlebitis
  • Abscess formation, e.g. subphrenic or pelvic, depending on the surgery involved
• After 5 days
  • DVT
  • Specific complications related to surgery, e.g. bowel anastomosis breakdown, fistula formation
  • After the first week
  • Wound infection
  • Distant sites of infection, e.g. UTI
  • DVT, pulmonary embolus

• If large volumes of blood have been transfused, then haemorrhage may be exacerbated by consumption coagulopathy. May also be due to preoperative anticoagulants or unrecognised bleeding diathesis.
• Perform clotting screen and platelet count, ensure good IV access and insert CVP catheter. Give protamine if heparin has been used. Order cross-matched blood. If clotting screen abnormal, give FFP or platelet concentrates. Consider surgical re-exploration at all times.
• Late postoperative haemorrhage occurs several days after surgery and is usually due to infection damaging vessels at the operation site. Treat infection and consider exploratory surgery.

• Infectious complications are the main causes of postoperative morbidity in abdominal surgery.²
• Wound infection: commonest form is superficial wound infection occurring within the first week presenting as localised pain, redness and slight discharge usually caused by skin Staphylococci.
• Cellulitis and abscesses: usually occur after bowel related surgery. Most present within first week but can be seen as late as third postoperative week, even after leaving hospital. Present with pyrexia and spreading cellulitis or abscess. Cellulitis is treated with antibiotics. Abscess requires suture removal and probing of wound but deeper abscess may require surgical re-exploration. Wound is left open in both cases to heal by secondary intention.
• Gas gangrene is uncommon and life threatening.
• Wound sinus is a late infectious complication from a deep chronic abscess that can occur after apparently normal healing. Usually needs re-exploration to remove non-absorbable suture or mesh, which is often the underlying cause.

Most wounds heal without complications and healing is not impaired in the elderly unless there are specific adverse factors or complications. Factors which may affect healing rate are:

• Poor blood supply
• Excess suture tension
• Long term steroids
• Immunosuppressive therapy
• Radiotherapy
• Severe rheumatoid disease
• Malnutrition and vitamin deficiency

Wound dehiscence

• Affects about 2% of mid-line laparotomy wounds
• Serious complication with a mortality of up to 30%
• Due to failure of wound closure technique
• Usually occurs between 7 and 10 days post operatively
• Often heralded by serosanguinous discharge from wound
• Should be assumed that the defect involves the whole of the wound
• Initial management includes opiate analgesia, sterile dressing to wound, fluid resuscitation and early return to theatre for resuture under general anaesthesia

• Occur in 10-15% of abdominal wounds usually appearing within first year but can be delayed by up to 15 years after surgery.
• Risk factors include obesity, distension and poor muscle tone, wound infection and multiple use of same incision site.
• Presents as bulge in abdominal wall close to previous wound. Usually asymptomatic but there may be pain, especially if strangulation occurs. Tends to enlarge over time and become a nuisance.
• Management: surgical repair where there is pain, strangulation or nuisance.

• Unavoidable tissue damage to nerves may occur during many types of surgery e.g. facial nerve damage during total parotidectomy, impotence following prostate surgery or recurrent laryngeal nerve damage during thyroidectomy.
• There is also a risk of injury while being transported and handled in the theatre under general anaesthetic. These include injuries due to falls from trolley, damage to diseased bones and joints during positioning, nerve palsies, diathermy burns.

• Occur in up to 15% of general anaesthetic and major surgery and include:
• Atelectasis (alveolar collapse):
  • Caused when airways become obstructed, usually by bronchial secretions. Most cases are mild and may go unnoticed.
  • Symptoms are slow recovery from operations, poor colour, mild tachypnoea, tachycardia and low-grade fever.
  • Prevention is by pre-and postoperative physiotherapy.
  • In severe cases, positive pressure ventilation may be required.
• Pneumonia: requires antibiotics, physiotherapy.
• Aspiration pneumonitis:
  • Sterile inflammation of the lungs from inhaling gastric contents.
  • Presents with history of vomiting or regurgitation with rapid onset of breathlessness and wheezing. Non-starved patient undergoing emergency surgery is particularly at risk.
  • May help avoid this by crash induction technique and use of oral antacids or metoclopromide.
  • Mortality is nearly 50% and requires urgent treatment with bronchial suction, positive pressure ventilation, prophylactic antibiotics and IV steroids.
• Acute respiratory distress syndrome
  • Rapid, shallow breathing, severe hypoxaemia with scattered crepitations but no cough, chest pains or haemoptysis, appearing 24-48 hours after surgery.
  • Occurs in many conditions where there is direct or systemic insult to the lung e.g. multiple trauma with shock.
  • Requires intensive care with mechanical ventilation with positive-end pressure.

• Major cause of complications and death after surgery. DVT is very commonly related to grade of surgery.³
• Many cases are silent but present as swelling of leg, tenderness of calf muscle and increased warmth with calf pain on passive dorsiflexion of foot.
• Diagnosis is by venography or Doppler ultrasound.

Pulmonary embolism:

• Classically presents with sudden dyspnoea and cardiovascular collapse with pleuritic chest pain, pleural rub and haemoptysis. However, smaller PEs are more common and present with confusion, breathlessness and chest pain.
• Diagnosis is by ventilation/perfusion scanning and /or pulmonary angiography or dynamic CT.
• Management: IV heparin or SC low molecular weight heparin for 5 days plus oral warfarin.

• Urinary retention: common immediate postoperative complication that can often be dealt with conservatively with adequate analgesia. If this fails may need catheterisation.
• UTI: very common, especially in women, and may not present with typical symptoms. Treat with antibiotics and adequate fluid intake.
• Acute renal failure: may be caused by antibiotics, obstructive jaundice and surgery to the aorta. Often due to episode of severe or prolonged hypotension. Presents as low urine output with adequate hydration. Mild cases may be treated with fluid restriction until tubular function recovers. In severe cases may need haemofiltration or dialysis while function gradually recovers over weeks or months.

• Delayed return of function²
  • Temporary disruption of peristalsis: may complain of nausea, anorexia and vomiting and usually appears with the re-introduction of fluids. Often described as ileus.
  • More prolonged extensive form with vomiting and intolerance to oral intake called adynamic obstruction and needs to be distinguished from mechanical obstruction. If involves large bowel usually described as pseudo-obstruction. Diagnosed by instant barium enema.
• Early mechanical obstruction: may be caused by twisted or trapped loop of bowel or adhesions occurring approximately 1 week after surgery. May settle with nasogastric aspiration plus IV fluids or progress and require surgery.
• Late mechanical obstruction: adhesions can organise and persist commonly causing isolated episodes of small bowel obstruction months or years after surgery. Treat as for early form.
• Anastomotic leakage or breakdown: small leaks are common causing small localised abscesses with delayed recovery of bowel function. Usually resolves with IV fluids and delayed oral intake but may need surgery.
• Major breakdown causes generalised peritonitis and progressive sepsis needing surgery for peritoneal toilet and antibiotics. Local abscess can develop into a fistula.