| Technique
Although often performed in emergent
conditions, attention to technique in placing the chest
tube is vital to avoid complications from the procedure.
The chest tube is placed (on the correct
side) in the mid- or anterior- axillary line, behind pectoralis
major (to avoidhaving to dissect through this thick muscle).
On expiration, the diaphragm rises to the 5th rib at the
level of the nipple, and thus chest drains should be placed
above this level. Rib spaces are counted down from the
2nd rib at the sternomanubrial joint. Practically, the
highest rib space that can be easily felt in the axilla
(usually the 4th or 5th) is the most appropriate.
Chest tube insertion is a painful procedure,
especially in muscular individuals. A combination of intravenous
analgesia and local anaesthesia is used for the procedure.
An intravenous opioids such as morphine is standard analgesia
for trauma patients. It is best given in small aliquots
titrated to effect, to avoid subsequent respiratory depression
from overdose. An analgesic dose of ketamine (20mg adult)
is a good alternative to opioids for chest tube insertion.
For local anaesthesia, 10-20mls of local
anaesthetic is required. This is infiltrated under the
skin along the line of the incision. The needle is then
directed perpendicular to the skin and local anaesthetic
infiltrated through the layers of the chest wall down
onto the rib below the actual intercostal space. Here
local is injected around the periosteum of the rib. The
needle is then angled above the rib and advanced slowly
until air is aspirated. The last 5 mls or so of local
anaesthetic is then injected into the pleural space.
The steps in insertion of a chest drain
are as follows:
- The area is prepped and draped
appropriately
- An incision is made along the
upper border of the rib below the intercostal space
to be used.
The drain track will be directed over the top of the
lower rib to avoid the intercostal vessels lying below
each rib.
The incision should easily accommodate the operator's
finger.
- Using a curved clamp the track
is developed by blunt dissection only. The clamp is
inserted into muscle tissue and spread to split the
fibres. The track is developed with the operator's finger.
- Once the track comes onto the
rib, the clamp is angled just over the rib anddissection
continued until the pleural is entered.
- A finger is inserted into the
pleural cavity and the area explored for pleural adhesions.
At this time the lung, diaphragm and heart may be felt,
depending on position of the track.
- A large-bore (32 or 36F) chest
tube is mounted on the clamp and passed along the track
into the pleural cavity.
- The tube is connected to an
underwater seal and sutured / secured in place.
- If desired, a U-stitch is placed
for subsequent drain removal (see below).
- The chest is re-examined to confirm effect.
- A chest X-ray is taken to confirm
placement & position.
For blunt trauma patients lying supine,
drains should be placed anteriorly in the chest. This
pevents a tension pneumothorax developing if the chest
tube is blocked by dependent lung tissue. Normal movement
of the lungs will allow drainage of a basal haemothorax
through an anterior chest tube.
|
 |
Drain in oblique
fissure
blocked by lung tissue |
Lower chest CT showing
tension pneumothorax
|
For penetrating trauma where patients
are not restricted to the supine position, haemothoraces
may be more efficiently drained with a posterior, basally
directed drain.
The final resting place of the tube
is determined in part by the direction of the track it
follows through the chest wall. If a drain is to lie anteriorly
in the chest, the track should be developed in a slightly
anterior direction. If the track is directed posteriorly,
the drain may fall back to lie in the oblique fissure,
where it may become blocked with lung tissue.
Chest tubes should be inserted so that
the last hole of the drain is inside the thoracic cavity.
However if passed too far into the chest, drains can cause
severe intractable pain as they abut the mediastinum.
|
|
Drains inserted
too far
into thoracic cavity |
Drain not fully
inserted
Last hole nearly out |
An underwater seal is used to allow
air to escape through the drain but not to re-enter the
thoracic cavity. The drainage bottle should always be
kept below the level of the patient, otherwise its contents
will siphon back into the chest cavity.
Persistent bubbling of air through the
water indicates an air leak from the lung. Chest tubes
should NEVER be clamped for any reason, to avoid the development
of a tension pneumothorax.
The air outlet of the underwater seal
may be connected to moderate suction (-20cm water) to
assist in lung re-expansion. This is more important in
the presence of an air leak.
Chest drains may be removed when they
are no longer draining any fluid and any air leak has
resolved. Removal is ideally performed with two people
- one to remove the tube and one to occlude the drain
site. The tube should be removed either at the end of
expiration or at peak inspiration, to avoid further air
being entrained into the pleural cavity.
The area is cleaned and sterilised.
An occlusive dressing is prepared and held ready. Any
stay sutures are removed. With the patient holding his
breath (out or in), the tube removed rapidly and the occlusive
dressing applied.
Some surgeons prefer to use a purse-string
or U-suture to close the wound. This may be placed at
the time of drain insertion. While there is no detriment
in using a closing suture, they probably serve little
purpose and the purse-string especially may produce an
ugly scar.
Complications
"There is no organ in the thoracic
or abdominal cavity that has not been pierced by a chest
drain." Chest drains used to be inserted with a steel
trocar and a lot of brute force. If a trocar comes with
the chest drain set it should be discarded or only used
to hold up tomato plants.
- Haemothorax, usually from laceration
of intercostal vessel (may require thoracotomy)
- Lung laceration (pleural adhesions
not broken down)
- Diaphragm / Abdominal cavity penetration
(placed too low)
- Stomach / colon injury (diaphragmatic
hernia not recognised)
- Tube placed subcutaneously (not in
thoracic cavity)
- Tube placed too far (pain)
- Tube falls out (not secured)
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