Keywords Airtraq - endoscopic third ventriculostomy - obstructive hydrocephalus
Introduction
Hydrocephalus makes airway management challenging mainly due to the increased circumference
of head, difficulty in positioning for intubation, and other associated congenital
anomalies. The probability of hypothermia along with rise in intracranial tension
(ICT) may lead to herniation, respiratory and cardiac arrest, and possibly death during
management of hydrocephalic infants.[1 ]
These days, a variety of video laryngoscopes are available for managing anticipated
difficult airway, but experience and familiarity with the device used are certainly
more important than the actual device itself.
There are scarce case series available on the use of pediatric Airtraq in hydrocephalic
infants. The pediatric Airtraq optical laryngoscope is an airway device, which facilitates
tracheal intubation in infants having both normal, as well as difficult airways. An
application (Airtraq mobile by Airtraq) that allows live picturing of the intubation
process has been made freely available on Google play (for Android) and Application
Store (for iPhone). It works along with a specially designed adaptor (A-308) for smartphone
manufactured by Prodol Meditec Limited, Zhuhai, Guangdong, China. Airtraq is distributed
through the worldwide AIRTRAQ distributors’ network (Prodol Meditec SA; Las Arenas,
Spain;
[Fig. 1 ]
).
Fig. 1 Airtraq mounted on universal adaptor for smartphone.
We report a series of eleven infants with obstructive hydrocephalus posted for endoscopic
third ventriculostomy (ETV) who were successfully intubated using Airtraq with smartphone
adaptor.
Case Series
After obtaining written informed consent, 11 infants under 1 year of age, who presented
with obstructive hydrocephalus and were scheduled for ETV, were selected for this
case series. Data regarding age, sex, congenital anomalies, and any neurological deficit
were noted.
A thorough preoperative evaluation was done including the possibility of other congenital
and genetic anomalies, and neurologic deficits, as well as any signs of raised intracranial
pressure (frontal bossing, dilated scalp veins, and cranial nerve palsies). Routine
laboratory results were obtained along with CT scan. None of the infants had any associated
congenital anomalies.
Demographic and airway assessment records are depicted in [Table 1 ]. The Mallampati grading was difficult to assess, and airway assessment was done
by Colorado Pediatric Airway Score (COPUR;
[Fig. 2 ]
). This scale rates chin size, interdental opening, previous intubation or OSA, uvula
visualization, and estimated range of motion of neck on a four-point scale. Scores
above 10 predict difficult intubation.
Fig. 2 Freemantle scores in pediatric population.[9 ] CT, Cormack Lehane; POGO, percentage of glottis opening; TT, tracheal tube.
Table 1
Demographic and airway assessment data
Case
Age (mo)
ASA status
Weight (kg)
COPUR score
Freemantle score view
Fremantle score ease
Expert satisfaction
Abbreviations: ASA, American Society of Anaesthesiologists; COPUR, Colorado pediatric
airway score; F, full view; P, partial view.
1
08
I
6.2
6
F
1
1
2
11
II
9
9
F
1
1
3
12
I
11
8
F
1
1
4
09
I
5.3
9
F
1
1
5
07
II
8
9
F
1
2
6
08
II
13
12
P
2
2
7
09
I
10
8
F
1
1
8
11
II
8.2
10
F
1
1
9
12
II
8
7
F
1
1
10
09
I
9
10
P
2
1
11
10
II
8.2
12
P
2
1
A standardized protocol for anesthesia was maintained for all cases. Airtraq intubation
was achieved by an experienced and skilled anesthesiologist (>50 uses). All children
were kept nil per mouth as per standard guidelines. They were premedicated with atropine
0.02 mg/kg intravenously (IV), dexamethasone 0.5 mg/kg IV, and fentanyl 2 µg/kg IV
in the OT, and standard monitoring including pulse oximetry, electrocardiogram (ECG),
noninvasive blood pressure recording, and temperature monitoring were established.
The infants were positioned with a shoulder roll, the head (occiput) was laid on a
thin head ring while the body allowed to rest on the stack, so as to align the glabela
horizontally with the chin, the external auditory meatus (EAM) with suprasternal notch
(SN), and neck wide open.
Preoxygenation was adequately provided with 100% oxygen through a face mask, followed
by anesthetic induction with inhalation of 8% sevoflurane in 50% nitrous oxide (N2 O) and 50% oxygen (O2 ), the inspired concentration was reduced to 4% when pupils diverged. Centralization
of pupils and absence of hemodynamic response to jaw thrust were deemed to confirm
adequate depth of anesthesia for intubation. None of the infants received muscle relaxants
prior to intubation.
An infant Airtraq laryngoscope (size zero) with adaptor was introduced midline into
the oral cavity over the tongue base and the tip placed in the vallecula. Trachea
was intubated with age appropriate uncuffed endotracheal tube in the first attempt
after centralizing the vocal cord in the proximal view finder, which required slight
adaptation of Airtraq and wrist movements pulling the Airtraq back and up (
[Fig. 3 ]
). Correct positioning of endotracheal tube was confirmed by capnography and chest
auscultation bilaterally. Anesthesia was maintained with 1 to 2% sevoflurane and 60%
N2 O in O2 .
Fig. 3 View of Airtraq with adaptor video laryngoscope.
We used Airtraq with adaptor in difficult airway cases, following the same recommendations
as applied for direct laryngoscopy, implying that no more than two attempts were made
with the same device. Maneuvering techniques such as the use of introducers or intubation
guides at the time of insertion[2 ]
[3 ] and external laryngeal manipulations were used according to Fremantle’s score (
[Fig. 2 ]
).[4 ]
Expert satisfaction about device adaptor was rated ranging from 1 to 4 (1 = better
than without adaptor and useful; 2 = normal, not different than without adaptor; 3
= worst; and 4 = extremely worst/worse and inutile).
Discussion
Congenital hydrocephalus is commonly associated with Arnold–Chiari, myelomeningocele
or Dandy–Walker malformations, arachnoid cysts, and vascular malformations. Acquired
hydrocephalus may be a consequence of infection, intraventricular hemorrhage, trauma,
and tumors.[5 ]
Anesthetic management for patients with obstructive hydrocephalus posted for ETV poses
specific challenges; airway management in small patients with large heads along with
anatomical and physiological differences, maintaining adequate cerebral perfusion,
and preventing rise in ICT during the surgery, especially during intubation and endoscopy.
A large occiput, in these patients, places the neck in extreme flexion and large forehead
may obscure the view of laryngoscopy. Therefore, optimum position was made, so as
to align glabela horizontally with the chin, the EAM with SN, and the neck wide open.
Securing the airway in a timely and effective manner is a priority in these patients
due to respiratory problems secondary to laryngospasm, bronchospasm, and hypoxia.
Airtraq, an indirect laryngoscope has an optical channel accommodating a series of
lenses, prisms, and mirrors that reflect the magnified image from the tip of the blade
to the viewfinder.[6 ] It has a channel in which the endotracheal tube is loaded and advanced. Since direct
line of sight is not required, there is neither need to displace the tongue nor that
of the sniffing position.
The Airtraq allows better glottis visualization than direct laryngoscopy.[7 ] It demands special consideration because of its easy maneuvering, low cost, and
more rapid learning curve.[6 ] There are two sizes of pediatric Airtraq available: infant (endotracheal tube size,
2.5–3.5 mm ID) and child (endotracheal tube size, 4.0–5.5 mm ID).[8 ]
The use of smartphone has gradually become popular among anesthesiologists.[9 ] The addition of smartphone to an Airtraq provides a high-quality view, allowing
image recording, editing, analysis, and sharing for teaching purpose, without changing
the line of sight.[10 ] However, with regard to recording of patient data on a smartphone, legal issues
should be considered.
In our case series, we have attempted to prove that the Airtraq with adaptor may be
an alternative to intubation with video laryngoscopy, especially in the developing
countries. Advantages of Airtraq with adaptor are that it works as a videolaryngoscope,
its feasibility, ease of assistance and guidance. We found 8 of 11 (72.7%) full Freemantle
score in our patients. According to the expert opinion, 9 of 11 (81.8%) patients rated
it as useful and better than without the adaptor. Intubation using Airtraq with smartphone
adaptor thus improved the visualization of the vocal cords and provided greater satisfaction
during airway management.
It is reported by Vlatten et al, wherein a 5-month-old infant with Pierre–Robin sequence
was successfully intubated using Airtraq.[11 ] Similarly, a 3-month-old child of Apert syndrome with difficult airway was intubated
with Airtraq.[12 ] Péan et al intubated a 10-year-old child, which was a case of difficult airway due
to the Treacher Collins syndrome with 5.5 ID armored tracheal tube using a size-2
Airtraq.[13 ] Ali et al reported a case where they successfully intubated a 3-month-old infant
with occipital meningocele using Airtraq.[14 ]
Until now, no case report describing the use of Airtraq with adaptor in pediatric
hydrocephalus has been discussed in literature.
Conclusion
The successful execution of anticipated difficult intubation largely depends on adequate
preoperative evaluation, assessment, planning, preparation, and finally execution.
This case series highlights the utility of Airtraq with smartphone adaptor in infants
with hydrocephalus with known difficult airway. The authors are of the opinion that
intubation with this device is a better and more feasible alternative for known difficult
intubations in any hospital setting, mainly in developing countries where resources
are scarce. It can be used as an effective primary technique or rescue device in patients
of anticipated difficult airway as in infants with obstructive hydrocephalus.
