9.5 BPF + Paravertebral Block Flashcards
comment on the X-ray in Figure 9.5.
CXR – PA view
No bronchovascular markings on left hemithorax
Air with fluid level on the left side
Mediastinal shift to right
Diagnosis – Hydropneumothorax.
What is bronchopleural fistula
(BPF)?
Bronchopleural fistula is the abnormal communication
between pleural cavity and the bronchial tree.
It is defined as persistent air leak for greater than 24 hours
after the development of pneumothorax
or failure to inflate the lung despite chest drainage for 24 hours.
How is BPF diagnosed?
clinical presentation—as above
CXR: Radiological features that are suggestive of diagnosis include:
- Steady increase in intrapleural air space
- Appearance of a new air fluid level
- Changes in an already present air fluid level
- Development of tension pneumothorax
CT
* Pneumothorax, pneumomediastinum
* Underlying lung pathology
* Presence of actual fistulous communication
What are the causes of BPF?
The most common cause of BPF is
positive pressure ventilation after thoracotomy
leading to dehiscence of the bronchial stump,
which presents at 3–10 days post surgery.
Other causes are listed below.
1. * Infection
° Necrotising infection—lung abscess, empyema, tuberculosis
- Trauma
° Bullae rupture
° Thoracic trauma
- Trauma
- Iatrogenic/postsurgical
° Post-thoracotomy
° Post-chemo/radio therapy
° Boerhaave’s syndrome
- Iatrogenic/postsurgical
- Neoplastic
° Tumour invasion of bronchus from oesophagus or lung
- Neoplastic
- Diffuse lung disease
° Pneumocystis carinii pneumonia
° ARDS
- Diffuse lung disease
- Miscellaneous
° Spontaneous pneumothorax
- Miscellaneous
What are the presenting features of a persistent broncho pleural leak?
It depends on the onset and size of air leak
The underlying pathology and can have an
acute, subacute, or delayed presentation.
The symptoms and signs can vary from
simple productive cough to full-blown sepsis,
dyspnoea,
acute tension pneumothorax.
What are the problems encountered in ventilating patients with BPF?
Large BPF leads to inadequate ventilation due to the following:
- V/Q mismatch causing hypoxia and hypercapnia.
- Failure to expand the collapsed lung.
- Need for flow limitation to aid healing:
use of small tidal volume,
less PEEP, short inspiratory time,
and reduced respiratory rate—
all these manoeuvres reduce the
airway pressure and fistula flow but impair
ventilation at the same time. - Need for selective ventilation of the unaffected lung; differential, or
independent ventilation with the use of double lumen tubes. - High-frequency ventilation (HFV) had been successful in patients with
normal lung parenchyma and proximal BPF compared to patients with
lung disease. - Associated with high mortality.
How do you treat BPF surgically?
- Large BPFs not amenable to conservative management need intervention.
- The technique of treatment depends on the size and position of the fistula
and the underlying pathology. - Bronchoscopic application of sealants or sclerosing agents
is suitable for distal and small BPFs less than 5 mm. - Video-assisted thoracoscopic surgery (VATS) is a less invasive technique that
gives access to a wide range of therapeutic procedures. - Surgical closure of the bronchial stump with muscle flap,
additional lobectomy,
decortication might be needed.
What are the principles in anaesthetising a patient for corrective BPF surgery?
- Not a case for an occasional thoracic anaesthetist;
need experience in thoracic anaesthesia
and BPF management,
as this procedure carries a high mortality.
*Preassessment, * Protection of healthy lung , * Anaesthesia, * Analgesia, * Postoperative
*Preassessment
° Airway exam
° Chest drains
° Antibiotics if infectious cause is suspected
- Protection of healthy lung
° Chest drain before intubation
° Anaesthetise in lateral position with healthy lung in the nondependent position
° Prevent cross-contamination
° Avoid ventilation until the good side is isolated
What are the principles in anaesthetising a patient for corrective BPF surgery?
- Anaesthesia
° Rapid IV induction with prompt endobronchial intubation into good side
(or)
° Inhalational induction with spontaneous ventilation until lung isolation is achieved
(or)
° Awake fibreoptic intubation and lung isolation techniques
° Maintain anaesthesia preferably with TIVA to avoid volatile leak into the BPF
- Analgesia
+
Post operative
- Analgesia
° Very important to aid coughing and clearing secretions and prevent
atelectasis
° Needed for adequate incentive spirometry, physiotherapy, and early
mobilisation
° To prevent DVT, PE, and cardiorespiratory complications
_____________________________
- Postoperative
° Prompt discontinuation of positive pressure ventilation postoperatively
(negative pressure ventilation preferable)
° optimal analgesia with the use of short-acting anaesthetic drugs
to help with enhanced recovery
What are the various options for postoperative analgesia?
- Multimodal analgesia
° Paracetamol, NSAIDS, Tramadol, gabapentin, etc. - IV opioids, preferably as PCA
- Intrathecal opioid
- Thoracic epidural block
- Thoracic paravertebral block
- Intercostal block
- Intrapleural catheters
What are the causes of pain after thoracotomy?
- Incisional pain:
skin and muscles—
intercostal nerves, nerves supplying
serratus anterior and latissimus dorsi - Visceral pain:
vagus nerve - Referred pain:
ipsilateral shoulder pain due to pain referred from
pericardium and diaphragm - Neuropathic pain:
intercostal neuritis or damage to other peripheral nerves - Chest drain pain:
corresponding intercostal nerves
Explain the anatomy of paravertebral space.
Boundaries
The space is bounded by the following structures.
- Apex (laterally):
posterior intercostal membrane and intercostal space - Base (medially):
vertebral body, intervertebral disc, and the vertebral foramen
with its corresponding spinal nerve - Anterior:
parietal and visceral pleura and lung parenchyma - Posterior:
transverse processes of the vertebrae, heads of ribs and costotransverse ligament
The PVS communicates with epidural space medially through the
intervertebral foramina and intercostal spaces laterally.
Explain the anatomy of paravertebral space.
Contents
The division of the PVS into anterior subserous compartment
and posterior sub endothoracic compartment by the endothoracic fascia
is of no significant importance.
The contents include
- neural tissue surrounded loosely by areolar and adipose tissue.
- Spinal nerves:
with white and grey rami communicantes within the medial aspect of the PVS. - Sympathetic chain:
lies at the neck of the rib anterior to the intercostal neurovascular bundle.
What are the indications of paravertebral block (PVB)?
- Acute pain
a ° Surgical pain
– Unilateral thoracic surgery—
open thoracotomy,
video-assisted thoracoscopic surgery (VATS),
cardiac and breast surgery
– Unilateral abdominal surgery—
renal surgery and open cholecystectomy
b ° Nonsurgical pain
– Rib fracture
- Chronic pain
° Post-herpetic neuralgia
° Post-surgical chronic pain
° Relief of cancer pain (e.g. mesothelioma or deposits)
- Chronic pain
- Therapeutic
° Control of hyperhidrosis
- Therapeutic
The contraindications are similar to any other central neuraxial blockade.
How would you perform a thoracic paravertebral block for open thoracotomy?
Incision
Knowing the incision
Ascertain the extent of surgical procedure to know the dermatomal
distribution of the incision after discussion with the surgeon about the
planned approach and extent of surgery.
As a rough guide:
For VATS procedure: T3 to T8,
depending on the site of operation.
For muscle-sparing thoracotomy:
The incision is about 5–7 cm long
extending vertically from T2 to T9.
For posterolateral thoracotomy:
Incision spans over at least six dermatomal levels—
T3 posteriorly to T8 anteriorly,
with chest drains placed at 8th/9th intercostal space
.
(Total mastectomy requires blockade extending from T1 to T6 level.)
How would you perform a thoracic paravertebral block for open thoracotomy?
Level
Prerequisites
Choosing the type of block
Single or multiple injections:
If anaesthesia of several dermatomes is required a small volume,
multiple injection technique is recommended.
For example,
to block T3 to T8,
three injections at T3, T5, and T7 are done with 8–10 mL
of local anaesthetic at each level.
Prerequisites
Consent, intravenous access, noninvasive monitoring, presence of full
resuscitation facilities, and trained assistant.
PVB approach + technique
Landmarks
Approach and technique
The experience and local policy guides the choice of technique—
landmarks or nerve stimulator or ultrasound guided blocks.
The patient is positioned in the sitting or lateral decubitus position
(with the side to be blocked uppermost) and supported by an attendant.
To block T3 to T8, the skin is marked at tips of the spinous processes and
at points 2.5 cm lateral to these.
The parasagittal points correspond with appropriate transverse processes.
PVB approach + technique
Following strict aseptic precautions,
the site of injection is infiltrated with 2% lignocaine.
An 18 G (22g 7cm) graduated epidural needle is advanced perpendicular
to the skin,
until contact with the transverse process is established.
Loss of resistance (LoR) syringe with saline is attached to the needle,
and while continuously testing for LoR,
the needle is ‘walked off’ the structure in a caudad
and lateral direction and advanced approximately 1 cm
(a maximum of 1.5 cm).
As the costotransverse ligament is penetrated, a ‘pop’ is felt as the needle
1enters the PVS. This is aptly called a ‘change of resistance’ rather than LoR,
as the complete LoR is experienced when the needle punctures the pleura
and goes intrapleural.
After careful aspiration to confirm that the needle tip is not intravascular
or intrathecal, the predetermined dose of local anaesthetic should be
administered
What are the advantages of PVB over epidural block?
Procedure
* Easy to teach, learn, and perform
* Can be done in anaesthetised patients
Side effects
- Decreased neurological complications:
PDPH, radicular pain, paraplegia, and peripheral nerve lesions.
- Decreased neurological complications:
- Decreased side effects:
less sedation, nausea, and vomiting, as PVB is
dependent on the use of local anaesthetics only.
Systemic opioid might be used; thus, opioid-related risks are minimised but not absent.
- Decreased side effects:
- Decreased cardiovascular side effects:
severe hypotension is rare
because of the unilateral blockade.
- Decreased cardiovascular side effects:
- Decreased or no incidence of urinary retention.
- Lack of motor blockade of the lower extremities.
- Better preservation of pulmonary function.
What are the advantages of PVB over epidural block?
Effects
Effects
PVB provides analgesia comparable to an epidural
without its side effects.
The block is equivalent to epidural in terms of success rate,
postoperative pain scores,
and analgesic efficacy.
(Better analgesia compared to intrapleural block.)
Effects similar to epidural block
- Inhibition of chronic pain by preventing sensitisation
of the CNS by blocking the ‘sensory flow’ - Prevention of cardiopulmonary complications
and decreased perioperative morbidity
What are the complications of PVB?
- Adequacy of the block
* Failure up to 5% - Damage to surrounding structures
* Parietal pleural puncture—intrapleural block
* Parietal and visceral pleural puncture—pneumothorax
* Vascular puncture—bleeding, haemothorax, local anaesthetic toxicity
* Epidural placement
* Dural puncture—high spinal, PDPH - Extension of the block
* Bilateral block—10%
* Stellate ganglion block (hoarseness) in high-thoracic PVB
