Keywords brain injury - penetrating - video laryngoscope - Glasgow coma scale - knife
Introduction
Penetrating brain injuries (PBIs) are rare events in modern times. These are caused
by violence, suicide, road traffic, and work accidents.[1 ] Patients who survive such injuries require foreign body removal. Further neurological
deterioration, life-threatening hemorrhage, or death can occur while providing anesthesia,
positioning, and foreign body removal.[2 ]
[3 ] There are few case reports describing anesthesia management of PBI, and none describing
intubation challenges in abnormal positions due to foreign body in situ. So, here
we present the case of an adolescent with a knife lodged in the occipital region needing
surgical care.
Case Report
A previously well, 13-year-old adolescent boy, presented with an alleged history of
assault with a knife. There was a small puncture wound over the right occipital bone
with the knife in situ. The external length of the knife was 14 cm and the intracranial
length was 1.8 cm. There was no history of headache, nausea, vomiting, convulsion,
or decreased vision. The patient was vitally stable. The Glasgow coma scale (GCS)
on arrival was 15/15 with no lateralizing signs. Systemic examination was also within
normal limits. Airway examination performed in the lateral position showed a Mallampati
score of 2, inter-incisor gap of 3.5 cm, and thyromental distance of 6.5 cm. Computed
tomography (CT) scan of the brain demonstrated the distal part of the knife in the
suboccipital bone penetrating beyond the inner table with the corresponding metal
streak artifact. CT venogram revealed suspicious injury to the right transverse sinus.
The rest of the brain parenchyma appeared normal ([Fig. 1 ]).
Fig. 1 Computed tomography (CT) of the brain showing knife blade in the occipital bone with
the corresponding metal streak artifact with CT venogram sagittal view.
Removal of the foreign body was mandatory as it jeopardized the patency of right transverse
sinus. After administration of antiepileptics, tetanus toxoid, antibiotic prophylaxis,
and confirming nil by mouth (NBM), the patient was moved into the operation theater
for retrieval of the foreign body. Standard American Society of Anesthesia (ASA) monitors
were attached. An 18-gauge intravenous (IV) cannula was secured in the right arm and
IV fluid Ringer lactate was administered. Difficult airway cart as per ASA guidelines
was kept ready for intubation in the lateral position.
The patient was premedicated with glycopyrrolate (0.004 mg/kg), midazolam (0.03 mg/kg),
and fentanyl (2 mcg/kg). After preoxygenation with 100% oxygen for 3 minutes, anesthesia
was induced with graded doses of propofol till loss of consciousness. Injection rocuronium
bromide 1 mg/kg was administered only after confirming adequate ventilation. Intubation
was performed in the lateral position with the help of video laryngoscope (HugeMed,
Shenzhen, China) and MAC no. 3 blade by a senior anesthetist with an assistant performing
external laryngeal manipulation (ELM). The trachea was intubated with a cuffed endotracheal
tube no. 7. Another assistant was asked to support the patient's right shoulder during
intubation to minimize the movement ([Fig. 2 ]). The Modified Cormack–Lehane grade was 2B, which improved to 1 with ELM. The lungs
were ventilated with volume-controlled ventilation with an oxygen-to-air ratio of
1:1, a tidal volume of 7 mL/kg, and a respiratory rate of 14 breaths per minute. General
anesthesia was maintained with inhaled isoflurane and intermittent divided doses of
rocuronium. Invasive BP monitoring was initiated in the left radial artery.
Fig. 2 (A ) Position for intubation. (B ) Position for surgery on Mayfield clamps. (C ) Before craniotomy. (D ) Foreign body after retrieval. (E ) After closure.
After local infiltration, Mayfield clamps were applied and the prone position was
given meticulously ([Fig. 2 ]).
Tranexamic acid 500 mg was administered prior to craniotomy. A linear incision was
made in continuity with the puncture wound. After drilling a single burr hole around
the entry site, bone around the knife was removed in pieces. Thereafter, the foreign
body was carefully removed. A small 3 × 2 mm rent was found in the right transverse
sinus, bleeding from which was controlled with dural hitch sutures ([Fig. 2 ]). There was a transient fall in mean arterial pressure (MAP) to 55 mm Hg following
retrieval of the knife. This was treated with IV fluids and 12 mg of ephedrine. Thereafter,
one bag of packed red blood cells was transfused. The patient remained vitally stable
with an MAP between 70 and 80 mm Hg for the rest of the procedure. A thorough antibiotic
wash was given after achieving hemostasis. The patient was kept normothermic using
forced air warmer. The patient was euglycemic and normocapnic (32–35 mm Hg) during
the procedure. Analgesia was provided with fentanyl (total 4 mcg/kg) and paracetamol
1 gm infusion.
The neuromuscular blockade was reversed and the patient was extubated taking care
that the patient does not cough on the tube.
Injection phenytoin and injection amoxicillin and clavulanic acid were administered
for 7 days. The convalescence was uneventful ([Fig. 3 ]).
Fig. 3 Postoperative computed tomography (CT) scan with 3D reconstruction.
Discussion
Blind removal of the penetrating foreign body carries the risk of subdural hematoma
and intraparenchymal hemorrhages along with injury to major neurovascular structures;
hence, craniotomy is recommended.[3 ]
It is paramount that cerebral vasculature near the path of the penetrating object
be evaluated to rule out a traumatic aneurysm or vascular dissection. In our case,
it was suspected to have penetrated the transverse sinus and hence CT venography was
performed.[4 ]
The first challenge was intubating in the lateral position. McCaul et al stated that
the left lateral position deteriorated laryngoscopic views in 35% of their patients
when compared to the supine position.[5 ] Nathanson et al demonstrated that intubation took longer and was more difficult
in the left lateral position than in the supine position, but intubation success improved
with practice, indicating a learning curve.[6 ] Goh et al mentioned that the lateral position is ergonomically challenging for the
laryngoscopist and intubating in the left lateral position is easier than in the right
lateral position as the tongue falls to the left, making glottic view superior.[7 ]
The ASA 2022 difficult airway guidelines recommend performing an awake intubation
if there is possibility of difficult intubation and one or more of the following apply:
(1) difficult ventilation (face mask/supraglottic airway), (2) increased risk of aspiration,
(3) the patient is incapable of tolerating a brief apneic episode, or (4) there is
expected difficulty with emergency invasive airway rescue. An uncooperative or pediatric
patient also restrict the options for awake intubation.[8 ] Hence, intubation after general anesthesia was chosen.
The guidelines also state that if a noninvasive approach to airway management is selected,
identify a preferred sequence of noninvasive devices.[8 ] If difficulty is encountered with individual techniques, combination techniques
may be used. As per these guidelines, success rate of video-assisted laryngoscopy
was similar to awake fiberoptic intubation.
Hence, the use of video laryngoscope combined with ELM helped us perform intubation
in first attempt with minimal neck extension.[9 ] Use of video laryngoscopy with bougie was our second choice, followed by laryngeal
mask airway-guided fiberoptic intubation. In our case, any amount of movement or extension
of the neck could cause the foreign body to impinge onto the cerebellum or shear the
transverse sinus; hence, we had to be mindful of this.
Penetrating objects have a tamponade effect and hemorrhage may occur during the extraction
of the sharp.[2 ] Retrieval of the sharp object in our patient was followed by blood loss and hypotension,
which was managed with crystalloids and blood. Use of invasive blood pressure monitoring
aided us in beat-to-beat monitoring.
The goals of anesthesia, that is, optimization of cerebral perfusion pressure (CPP)
and prevention of secondary brain injury, were achieved. Anesthesia management was
similar to that described by Parua et al,[2 ] Dalal and Vijayan,[3 ] Awori et al,[4 ] Khandelwal et al,[10 ] and Mbengono et al,[11 ] at par with the latest brain trauma foundation guidelines.
Antibiotics were continued to prevent infection and sepsis for 7 days. Although the
brain parenchyma was not injured, the child could have developed seizures due to concussion
or cerebral venous sinus thrombosis. Hence, antiepileptics were also administered
for 7 days.[2 ]
[10 ]
[12 ]
Conclusion
In cases of PBI with weapon in situ, one must be prepared for a difficult airway as
intubation may have to be performed in positions other than supine. In our patient,
intubation and positioning were an additional challenge due to the possibility of
impingement of the cerebellum or shearing of the transverse sinus by the weapon. Other
goals are to maintain CPP and avoid secondary brain injury. But long-term follow-up
will be required to identify delayed complications.
