Atelectasis + Pneumonia Flashcards
Differentials for post-op causes of SOB
- Atelectasis
- Pneumonia
- DVT + PE
- Fat embolism
- ARDs
What is atelectasis?
- Partial collapse of small airways
- Majority of post surgical patients develop to some extent
- Often pre-cursor to more severe pulmonary complications
Pathyphys of atelectasis
Not fully understood
But airway collapse due to combination of:
* airway compression
* alveolar gas resorption intra-operatively
* impaired sufactant production
What happens in atelectasis? How does it progress?
- Reduced airway expansion
- Accumulation of pulmonary secretions
- This predisposes patients to pulmonary complications eg hypoxaemia, reduced lung compliance, infection and acute respiratory failure
When does atelectasis typically occur?
- Develop within 24hrs usually
- Degree of lung tissue involved is variable
RF for atelectasis
- Age
- Smoking
- Use of general anaesthetic
- Duration of surgery
- Pre-existing lung or neuromuscular disease
- Prolonged bed rest (esp with limited position changes)
- Poor post op pain control = shallow breathing
Clinical features of atelectasis on examination
- Increased RR
- Decreased O2 saturations
- Fine crackles over affected tissue
- Sometimes low grade fever
Investigations for atelectasis
- Clinical diagnosis usually - esp if developed within 24hrs of surgery
- CXR can reveal small areas of airway collapse - if further imaging needed CT chest but rare to do
Management atelectasis
- Deep breathing exercises
- Chest physiotherapy
- = airways maximally opened and coughing can be performed effectively
- Adequate analgesia
What to do if no improvement seen following physiotherapy for atelectasis?
- Bronchoscopy may be needed
- Can aid suctioning out pulmonary secretions - but not routinely performed
Prevention of atelectasis
- All patients who have undergone major surgery should be referred to get chest physiotherapy
- CPAP may reduce risk post op
4 main types pneumonia
- CAP
- HAP
- Aspiration
- Immunocompromised
Cause of pneumonia in post op patients
- Reduced chest ventilation - less mobility, accumulate secretions
- Change in commensals - in hospital environment
- Debilitation - unwell, several co-morbids = compromised immunity
- Intubation - RF for HAP
Common causes of HAP
- Escherichia coli - gram -ve bacilli
- MRSA - gram +ve cocci, clusters
- Streptococcus pnuemonia - gram +ve cocci, chains
- Pseudomonas aeruginosa - gram -ve bacilli
What is ventilator associated pneumonia?
- HAP that occurs >48hrs after tracheal intubation
- Most common HAP in patients receiving mechanical ventilation
- Most common if have endotracheal tube in situ - prevents coughing, encourages aspiration of pharyngeal contents
RF for pneumonia
- Smoking
- Increasing age
- Known respiratory disease or recent viral illness
- Poor mobility - baseline or post op
- Mechanical ventilation
- Immunosupression
- Underlying co-morbids
Clinical features pneumonia
- Cough - productive or non-productive
- Dyspnoea
- Chest pain
BUT this is difficult as patients post op can have reduced conc level or be intubated. Sometimes just tired, fever and impaired cognition
Examination for pneumonia
- Reduced O2 sats
- Increased RR and HR
- Pyrexia
- Bronchial breath sounds (localised or diffuse)
- Inspiratory crackles
- Dull percussion
Bedside and bloods for suspected pneumonia
- FBC, CRP, U&E
- ABG - if O2 desaturation
- Sputum culture
- Blood cultures if septic
What to do if sputum sample unobtainable or severe/non-responding infection?
- Bronchoalveolar lavage - pass fluid into airway and then sample that fluid
Management pnuemonia
- O2 therapy - target sats 94% or more
- Emperical abx - guided by local policy
CURB 65 scoring and severity meaning
- 0-1 - mild - home treatment
- 2 - moderate - consider hosp admission
- 3 or more - severe - urgent admit
Example regime of abx for HAP pneumonia dependent on CURB65 score
- Mild - Co-amoxiclav oral
- Moderate - Co-amoxiclav oral
- Severe - Tazocin IV
Prevention of pneumonia post op
- Chest physiotherapy post op if risk of prolonged bed rest or reduced mobility
Complications of pneumonia
- Pleural effusion
- Empyema
- Respiratory failure
- Sepsis
What can happen if gastric contents are aspirated?
- Chemical pneumonitis
- Not necessarily infection - only if oropharyngeal bacteria are aspirated
Where does aspirated content tend to affect in lungs and why?
- Right middle or right lower lung lobes - shorter, more vertical and wider bronchus
- Due to anatomy of bronchi
RF for aspiration pneumonia in surgical patients
- Reduced GCS
- Iatrogenic interventions eg misplaced NG tubes
- Prolonged vomitting without NG tube insertion
- Underlying neurlogical disease
- Oesophageal strictures/fistula
- Post-abdominal surgery
Management pneumonitis and aspiration pneumonia
- Preventative - eg NG tube placement, SALT input
- Supportive
- If infected - antibiotics
