【Pediatric anesthesia】Selection of single-lung ventilation equipment for children

(1) There are three main indications for single-lung ventilation OLV

1.
Control the distribution of bilateral lung ventilation: bronchopleural (skin) fistula, huge unilateral lung cysts or bullae, and lung diseases
with asymmetric ventilation.

2.
Avoid fluid spillage or contamination of the unaffected lung: infection, bleeding and unilateral lung lavage
.

3.
Provide quiet surgical fields: thoracoscopic surgery, thoracotomy surgery and chest non-pulmonary surgery
.

There are currently three techniques or devices widely used to achieve double lung isolation
in pediatric patients.

Traditional single-lumen endotracheal tube selective endobronchial intubation
.

Bronchial closure device
.

Double-lumen tube (DLT).

Different anesthesia and intubation techniques
should be selected depending on the child's age, development, and availability of single-lung ventilation devices.
With the widespread use of fiberoptic bronchoscope (FOB), clinicians should use fiberoptic bronchoscope to position airway devices
visibly whenever possible.

1.
Endobronchial intubation

The simplest technique of lung isolation is to insert the ordinary endotracheal tube (ETT) across the ridge into the desired main bronchi
.
When blind inserted, ETT almost always enters the right main bronchus
.
To selectively perform left main bronchial intubation, the ETT must be rotated so that the anterior end is obliquely facing to the right, while the patient's head is rotated to the right and the human ETT
is continued to be inserted into the left main bronchi.
After endotracheal intubation, fiberoptic bronchoscopic positioning should be used, which requires familiarity with the anatomy of the bronchial tree below the ridge
.

Another method is to first place the ETT in the trachea, and then send the FOB through the endotracheal tube to the left or right main bronchus, guiding the ETT into the
target bronchi.
It should be noted that the smallest FOB diameter is 2.
2mm, and the mirror body is soft, which is difficult to guide the endotracheal tube forward, and it is easy

Damage to optical fiber
.
Therefore, caution should be exercised when using a fiberoptic bronchoscope to guide bronchial intubation
.

2.
Bronchial closure device

(1) Dethrombotic catheter/closure device: Wire-guided endobronchial blockers (WEB) can be effectively used in young children to achieve double lung isolation
.
The closure device can be placed inside or outside
the ETT.
The die of the Fogarty Closure Tube can be bent and shaped to place the endotracheal tube into either trachea and then position
it with FOB via ETT.
The closure tip is open to collapse the lung after isolation and, if necessary, to blow oxygen
.

(2) Guidewire-guided endobronchial occluder: Guidewire-guided endobronchial occluder is available in 5Fr
children's models.
The closure device is designed for placement in the ordinary ETT, and the guide wire snare at the front end of the plugper can be visually inserted in the front of the FOB
.
The capturator has three joints for ventilation after it is in place
.
The 5Fr WEB is available for the smallest ETT model is 5.
0mm, so it is usually only suitable for children
over 2 years old.

Plugging in the tube

For children under two years of age, bronchial closure devices can also be placed
snugly against the outside of the ET.
The rear end of the web cuff has a bend of 35~45 degrees to facilitate the operation into the correct position
.

The closure device is inserted through the nose or mouth into the larynx, and then the ETT is inserted along the web
.
Choosing a tracheal tube with an internal diameter (ID) 0.
5 mm smaller than the standard model facilitates the adjustment of the occluder position
within the trachea.
Manually adjust the occluder into the target bronchi by performing bronchoscopic positioning within the endotracheal tube
.
This technique allows the use of broncho closure devices
in children as young as 3 months of age.

(3) UniventTM tube and plugger: Univent tube (Fuji Systems Corporation, Tokyo, Japan) has a lateral branch cavity where bronchial closure devices can be placed, guide wires can be placed, and bent and shaped as needed for easy positioning
.
The smallest Univent tube is 3.
5mm inner diameter and 8mm outer diameter, equivalent to a 6.
0 cuffless tracheal tube, and is restricted to older children (approximately 8 years old
).
It should be noted that the Univent tube has two main disadvantages: (1) the Univent tube differs from the double-lumen tube in that it has a low-volume, high-pressure cuff at the front end, which may cause airway mucosal damage; (2) The occluder channel occupies a large cross-sectional area, leaving only a small lumen for patient ventilation
.

2.
Double-lumen tracheal intubation

Dual-lumen endotracheal intubation is the gold standard
for lung isolation techniques in adults.
However, the smallest models of 26Fr (Rusch, Duluth, GA, USA) and 28Fr (Mallinckrodt Medical, St Louis, MO) double-lumen tubes can actually only be used in older children aged 8 to 10 years, and their insertion method is the same
as that of adults.
Due to the large variation in body size in children, the placement depth of the double-lumen tracheal intubation is inconsistent, so its position
needs to be determined by fiberoptic bronchoscopy.

Notes / Wu Yajun

Typesetting/Amon