Post-op problems Flashcards
Name three cardiovascular post-op complications
- Hypotension
- HTN
- Myocardial infarction
- Venous thromboembolism
- Arrhythmias
List three precipitating factors for post-op myocardial infarction
- Stress response to major surgery: anxiety; pain
- Fluid overload post-op
- Profound hypotension
- Failure to restart anti-angina medication
What is the commonest post-op arrhythmia?
Atrial fibrillation
Why should pre-operative B-blockers be continued?
Sudden cessation in existing IHD:
- Rebound angina
- Infarction
How does pain affect post-op complications?
- CVS:
- Tachycardia
- HTN
- Increased myocardial O2 demand
- Resp: Basal atelectasis; chest infections
- GI: PONV, ileus
- Urinary retention
- Immobility; VTE
Give three causes of post-op breathlessness
- Upper airway obstruction; anaphylaxis
- Respiratory failure
- Basal atelectasis (24h)
- Pneumonia (3-5d)
- Pulmonary embolism (5-7d)
- Exacerbation of COPD
Define respiratory failure
Inadequate gas exchange in the respiratory system:
- Type I: PaO2 <8.0kPa on air
- Type II: PaO2 <8.0kPa and PaCO2 >6.0kPa
Outline the initial management of respiratory failure
- Sit patient up
- 15L high flow O2 in non-rebreathe mask
- Treat bronchospasm with neb salbutamol 5mg
- CXR
Why are post-op chest infections common?
Pain reduces:
- Breathing ➔ basal atelectasis
- Coughing ➔ decreases mucus clearance
Name three risk factors for post-op atelectasis
- Age
- Smoking
- General anaesthesia
- Longer duration of surgery
- Pre-existing lung or neuromuscular disease
- Prolonged bed rest
- Uncontrolled pain
How does post-op atelectasis present?
- Respiratory compromise
- Tachypnoea
- Reduced SaO2
- Fine crackles
- Low-grade fever
Outline the causes of post-op atelectasis
- Airway obstruction by bronchial secretions
- Hypoventilation
- Pain
Outline the management of post-op atelectasis
- Chest physiotherapy; deep breathing exercises
- Pain control
- CPAP if severe
Classify the types of post-op haemorrhage
Arterial (rare): rapid, bright red, pulsatile
Venous: low pressure, dark red, non-pulsatile
- Primary: immediately post-op or continuation of intra-op
-
Reactionary: within 24hr
- Unsecured blood vessels; slipped ligature
-
Secondary: 7-10 days post-op
- Vessel erosion from spreading wound infection
Outline the emergency management of post-op haemorrhage
- A-E assessment
- IV access >18G + fluid resuscitation
- Read operation notes: determine site; important info
- Direct compression of superficial bleeding
- Urgent senior surgical review + imaging
- Clotting, platelets, X-match 2+ units
- RBC; platelets; and FFP if severe
- Protamine sulfate to reverse heparin
- Consider activating major haemorrhage protocol
What blood products are available for managing haemorrhage?
- RBCs
- Fresh frozen plasma: all coagulation factors
- Platelets
- Cryoprecipitate: fibrinogen, Factor VII and VIII
- Tranexamic acid: inhibit plasminogen and plasmin
- Prophylatic use in cardiovascular surgery
What measures can be used to reduce the need for blood transfusion?
- Treating pre-operative anaemia and coagulopathies
- Stopping
- Warfarin (5d): may need ‘bridging’ LWMH till 24h pre-op
- Clopidogrel (7d)
- LMWH (24h)
List five causes of post-up pyrexia
-
Infection: days indicate most likely period
- ‘Wind’: LRTI (1-2d)
- ‘Water’: UTI (3-5d)
- ‘Wound’: Surgical site infections; abscess (5-7d)
- Infected lines (any day)
- ‘Walk’: VTE (4-6d)
- Iatrogenic: eg. transfusion, ‘Wonder’ about drugs (7+d)
- Prosthetic implantation: eg. Hip replacement; valve; stent
- Pyrexia of unknown origin
What is pyrexia of unknown origin?
- Recurrent fever (>38oC)
- Persisting for >3/52
- Without an obvious cause
- Despite >1/52 of inpt investigations
Causes: infection of unknown source; malignancy eg. lymphoma; connective tissue disease; vasculitis; drug reactions
Discuss the different types of surgical site infection
- Superficial surgical site infection: within the first week
- Localised pain, redness, and discharge
- Staph aureus
- Tx: Flucloxacillin 500mg PO QDS 5/7
- Abscess: most present within first week
- Usually after bowel surgery
- Pyrexia and spreading cellulitis or abscess
- Tx: Cefuroxime 1.5g IV TDS + Metro 500mg IV TDS
What peri-operative measures can reduce the risk of renal dysfunction?
- Pre-op: adequate hydration
- Eliminate nephrotoxic drugs where possible
- Postoperative: maintain satisfactory CO; fluids
Define oliguria and anuria
- Oliguria: urine output <0.5ml/kg/h
- Anuria: no measurable urine output
How does pulmonary oedema present following renal failure?
- Deteriorating blood gases
- Despite increasing respiratory support
- Hyperkalaemia
- Acidosis
Name two risk factors for post-op acute urinary retention
- Aged >50
- Male
- PMH of retention
- Abdomino-pelvic or urological surgery
- Spinal or epidural
- Neurological or urological co-morbidites
- Drugs eg. Opioids; anticholinergics
List three clinical features of acute urinary retention
- Little or no urine passed
- Suprapubic pain
- May be painless if previous chronic urinary retention
- Sensation of needing to void; inability to initiate micturition
- Suprapubic mass; dull percussion
Name two causes of post-op acute urinary retention
- Uncontrolled pain
- Constipation
- UTI
- Spinal or epidural
Describe the management of post-op acute urinary retention
- Reverse underlying factor
- Improve analgesia
- Treat constipation
- Mobilise
- Warm bath ➔ encourages micturition
- Restart any pre-op tamsulosin for BPH
- Relaxes prostate and bladder muscles
- Catheterisation
Name three post-op GI complications
- Post-op nausea and vomiting (PONV)
- Paralytic ileus
- Post-op mechanical small-bowel obstruction
- Constipation; diarrhoea
Give three patient risk factors for PONV
Patient factors:
- Female
- Younger age
- Previous PONV; motion sickness
- Opiods
- Non-smoker
Give three surgical risk factors for PONV
Surgical factors:
- Intra-abdominal laparoscopic surgery
- Intracranial or middle ear surgery
- Squint surgery
- Gynaecological surgery
- Prolonged operations
- Poor post-op pain control
Give two anaesthetic risk factors for PONV
Anaesthetic factors:
- Opioids or spinal
- Inhalation agents eg. isoflurane; nitrous oxide
- Prolonged anaesthesia
- Intraoperative dehydration/bleeding
- Excessive bag mask ventilation: gastric dilatation
Name three consequences of PONV
- Increased bleeding
- Incisional hernias; wound dehiscence
- Aspiration pneumonia
- Decreased absorption of oral medication
- Poor nutrition
- Hypokalaemia; metabolic alkalosis
How is PONV managed?
- Adequate hydration; analgesia
- Identify and treat any obstruction
- Cause-specific anti-emetic therapy:
- Impaired gastric emptying: Metoclopramide
- Bowel obstruction: Hyoscine
- Opioid-induced: Ondansetron; cyclizine
Name two intra-abdominal anastomoses with high risk of leak
Oesophageal and rectal anastomosis
Name three risk factors for anastomotic leak
Patient factors:
- Medication eg. steroids; immunosuppressants
- Smoking; alcohol excess
- Diabetes
- Obesity; malnutrition
Surgical factors:
- Emergency surgery
- Longer operation
- Peritoneal contamination
Request three investigation in suspected anastomotic leakage
- Gastrografin enema
- CT abdomen and pelvis with contrast
- FBC; CRP; U+Es; LFTs; clotting
- VBG
- G+S
Request three investigations for suspected post-op ileus
- FBC; CRP: U+Es
- CT abdomen and pelvis
Outline the management of post-op ileus
Must exclude serious pathology eg. anastomotic leak
- Daily bloods including U+Es
- Encourage mobilisation
- Reduce opiod usage
- Drip and suck: NBM + IV fluids ± NG tube
- Catheterisation
Differentiate post-op ileus from mechanical obstruction
Post-op ileus is a functional bowel obstruction
Absent bowel sounds rather than ‘tinkling’ bowel sounds
