Keywords
endotracheal - intubation - stylet
Plastic-coated stylets are commonly used during endotracheal intubation. The plastic
sheath eases the stylet removal from endotracheal tube (ETT) and minimizes the trauma
caused by its distal tip. However, they may host harmful risks to the patients. Shearing
of the plastic sheath may compromise the function of the ETT or the airways. We report
a complete severance of part of the stylet’s plastic sheath in a newborn.
Case Report
A 28 weeks gestation premature infant with birth weight of 970 g developed respiratory
distress syndrome causing oxygen desaturation and respiratory acidosis in blood gas.
The attending physician decided to perform endotracheal intubation for mechanical
ventilation support. A 2.5 mm uncuffed ETT threaded with 6-French (2-mm) plastic-coated
stylet (SMMP, Riyadh, Kingdom of Saudi Arabia) was used. After intubation the physician
could not remove the stylet from the ETT. The stylet was stuck inside the ETT but
eventually came out with force. The intubation attempt lasted more than 90 seconds
and the infant experienced a period of desaturation without bradycardias. After removal,
it was noticed that the distal part of the coated sheath is missing. The infant was
extubated and ~5-cm long plastic piece found embedded distally inside the ETT ([Fig. 1]). The infant immediately reintubated with a new set of ETT and stylet.
Figure 1 A 5-cm long piece of the stylet sheath retrieved from the endotracheal tube lumen
after extubation.
Discussion
Neonatal intensive care often involves using technologies and devices. Tracheal intubation
is an invasive procedure using a foreign body, the ETT. Improved staff training and
quality of devices reduce complications related to endotracheal intubation. Although,
it is considered to be safe and useful instrument, the stylet may pose a serious hazard
to the infant. The stylet is covered by a plastic sheath to minimize trauma from the
distal tip and ease withdrawal from the ETT. Retention of broken or sheared plastic
sheath from the stylet is rare but serious complication. Case reports are scarce in
the literatures but mainly included premature infants intubated with ETT size 2.5
mm, but term infants, ETT size 3 mm, and adult cases have been reported.[1]
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[9] We believe the few literature reports may not reflect the true incidence neither
the magnitude of the problem. Signs of airway obstruction, persistent respiratory
distress, oxygen desaturation, and difficult suctioning of ETT, despite a correct
placement of the ETT should alert the physician of possibility of this complication.
The plastic sheath is stretchable, pliable, and the malleable metal core should rotate
easily inside it. It is unclear how does the plastic sheath shear off. We speculate
that at different point of surface contact between the plastic sheath, the ETT externally
and the metal core internally, the frictional force is variable. During forceful withdrawal
of the stylet, the linear force created will be mounted at the point of maximum friction,
such as an angulation’s point at the stylet. These different points may be created
by kinks and bends in the metal core caused by excessive handling of the stylet.[10] Using a forceful withdrawal commonly attributed as a risk factor for the shearing.[1]
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The sheared fragment may dislodge or be pushed in further, causing more damage to
the airways or pulmonary parenchyma such as pneumothorax.[3] Suctioning of the ETT will be almost impossible in the presence of the obstructing
fragment.[5]
Pulling the stylet forcefully should be avoided, instead, if the stylet stuck inside
the ETT, we recommend to extubate the patient and reintubate with a new set of ETT
and stylet. Fitting and rotating the stylet into the ETT before intubation may ease
the stylet’s withdrawal without using excessive force. A bigger size ETT may be used
if indicated. Bending the stylet sharply to fit the ETT should be avoided because
most of the reported severed point occurs at the angulation point and consistently
reported as a risk factor.[6] The practice of completely removing the plastic sheath from the stylet before fitting
it inside ETT and seating the metal tip completely inside the ETT distally has been
advocated but not commonly used.[6]
The broken part of the plastic sheath has to be retrieved and should not be left inside.
The timing of retrieval is controversial. The fragment may advance deep to a location
too far to be accessed by endoscopy. Some authors do not recommend immediate removal
of the ETT because the fragment may migrate deep.[1] Boyd et al reported successful retrieval of a sheared endotracheal stylet’s sheath
from the left main bronchus by using the “Amplatz” gooseneck snare, a special catheter
used frequently to remove endovascular devices, guidewires, and their fragments.[7] We were fortunate that the ETT and the sheared plastic piece came out as one unit;
otherwise, the fragmented sheath may compromise the function of the ETT or the airway.
In case the stylet removed successfully while part of its plastic sheath sheared and
left inside the ETT, the physician has to assess the clinical condition of the infant.
Consulting a specialist in pediatric airway management or anesthetist versus extubation
and ETT withdrawal should be considered.
It is very important to carefully inspect the stylet’s integrity after withdrawal
and before using any positive pressure ventilation,[3] to use a new stylet for each intubation attempts, to minimize bending and rebending
the stylet, and to twist the stylet’s proximal end around the ETT adaptor. High index
of suspicion and vigilance will help in avoiding doing harm to patients.
