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CASE REPORT
Year : 2023 | Volume
: 14
| Issue : 2 | Page : 109-112
Awake fiberoptic intubation: The first mandatory choice of difficult airway – A report of two cases
T Krishna Prasad, C Dhinesh Kumar, Abinaya Devi, S Vijay Narayanan
Department of Anaesthesiology, Shri Sathya Sai Medical College and Research Institute, Sri Balaji Vidyapeeth (Deemed to be University), Kancheepuram, Tamil Nadu, India
Correspondence Address:
Dr. T Krishna Prasad
Shri Sathya Sai Medical College and Research Institute, Sri Balaji Vidyapeeth (Deemed to be University), Ammapettai, Kancheepuram - 603 108, Tamil Nadu
India
Source of Support: None, Conflict of Interest: None
DOI: 10.4103/injms.injms_6_23
We may have many devices in this 21st century, which can be used to secure the airway in patients who have been predicted to have a difficult airway. There are many studies about difficult airways and suggested various devices such as flexible fiberoptic scope, video laryngoscope, and the specialized intubating laryngeal mask airway and they ended up concluding one device better than another. Furthermore, ET intubation requires continued practice and carries with it its own set of complications. Technical problems with the placement of endotracheal tubes have been the most frequent cause of anesthetic deaths in published analyses from all over the world. The basic responsibility of an anesthesiologist is to maintain adequate gas exchange in patients by securing a patent airway through a proper device. Fiberoptic bronchoscopy and intubation have the advantage of being easier, with shorter intubation time and continuous oxygenation and ventilation throughout the procedure, especially in the case of children. We report two such cases, where “Awake flexible fiberoptic-guided intubation” was considered the only desirable choice.
Keywords: Airway, awake intubation, pediatric fiberoptic bronchoscopy, ventilation
It is essential for clinicians to understand the role and limitations of the available equipment to make appropriate choices. Although fiberoptic intubation (FOI) is an essential airway management skill for all anesthetists,[1],[2] there are substantial variations in the number of times one has to perform it before achieving competence. Opportunities to perform FOI are becoming increasingly limited due to a proliferation of alternative airway equipment such as supraglottic airways.
Unanticipated difficulties with mask ventilation in pediatric patients usually result from dynamic airway obstruction and respond favorably to prompt and appropriate interventions. These dynamic obstructions can be broadly categorized as supraglottic, glottic, and supraglottic obstruction.[3],[4] In view of various difficult airways, fiberoptic still holds an important role in many situations, and also holds a mandatory first choice in choosing from other available devices.
Case HistoryCase 1
Patient information
A 13-year-old boy weighing 27 kg came with a history of difficulty in opening his mouth following a traumatic fall. He presented to the department of oral and maxillofacial surgery, with limited mouth opening and difficulty in feeding, also he claimed it was difficult to perform proper tooth brushing [Figure 1].
Figure 1: Fusion of left TMJ and shortening of the mandible. TMJ: Temporomandibular jointClinical finding
A general examination showed he has a normal growth spurt, with average height and weight. His cognitive development is up to par. On extraoral examination, the child presented with an asymmetrical face, with reduced lower facial height, and deviated chin point to the left side. He also possessed a relatively small mandible, with a convex side profile. No movement of the left temporomandibular joint (TMJ) can be palpated through the external auditory canal. No mouth opening can be observed at all.
Surprisingly, the patient presented with excellent oral hygiene intraorally. There is an incomplete bite and a slight increase in the upper incisor proclination. His chest X-ray shows a bony fusion of the outer edges of the articular surfaces and a flattening of the condyle. Further imaging with a computed tomography (CT) scan showed that there is a bony fusion between the left condylar head and the base of the skull, with evidence of sclerosis and enlargement of the condylar head, extending into the sigmoid notch. The left TMJ space was entirely obliterated with bony deposition. Three-dimensional reconstruction of CT imaging confirmed the fusion of the left TMJ and depicted the shortening of the anteroposterior dimension of the mandible in the ankylotic left side as compared to the normal right side of the mandible.
The child was diagnosed with left TMJ ankylosis (Type IV) possibly secondary to trauma. The child was assessed to fit under the American Society of Anesthesiology Grade-LL with an anticipated difficult airway. After obtaining detailed assent from the parents (risk and benefit involved in difficult airways) and oral fasting of 6 h for semisolids. Operation theater was prepared with a difficult airway cart and kept ENT surgeon backup for emergency airway protection. The child was nebulized with glycopyrrolate (given for reducing the excessive mucus production) and prepared for a difficult airway. Furthermore, xylometazoline drops were instilled in both nostrils, the child shifted to OT, line secured, and preoxygenated with 100% 02 for 5 min followed by which he was induced with sevoflurane 8% in 100% 02 was given using Jackson Rees (JR) circuit and reduced gradually to 2.5% to maintain spontaneous breathing. Intravenous (IV) fentanyl 0.5 mcg/kg, IV hydrocortisone 1 mg/kg. Graduated doses of injection propofol 0.5–1 mg/kg were given with alertness in maintaining spontaneous respiration.
After confirming the adequacy of mask ventilation, the plane was deepened gradually to maintain Minimum alveolar concentration (MAC) of 1% for sevoflurane to facilitate passage of pediatric fiberoptic bronchoscopy (FOB). The tip of the scope was slightly tilted upward nearly 40° for aiding intubation from the head of the bed. Then, the tip of the scope is then advanced until the base of the tongue and advanced a little further directing to the glottic opening. Fine adjustments made with a slight motion of the wrist and elevation or depression of the tip using the angulation with the thumb control lever aid in directing the scope toward the vocal cords. A jaw thrust was provided by our assistant in between to aid in bronchoscope passage through the oropharynx and laryngopharynx.
A well-lubricated nasopharyngeal airway was placed in the right nostril and the JR circuit was fitted to it by an ETT connector to maintain an adequate plane and also to provide intermittent ventilation. In a deep plan of anesthesia pediatric flexible FOB (OD 3.8 mm and length 60 cm) preloaded with a cuffed endotracheal tube (ETT) 5 mm ID was inserted through the left nostril. The FOB was advanced and 2% lignocaine was sprayed on the visualization of vocal cords. Intermittent suction was done to facilitate better visualization. After FOB was in place within the trachea, ETT was railroaded and its position was confirmed with FOB. The scope crosses the vocal cords and the ETT which was previously loaded is slid toward the placement. The tube should be turned gently counterclockwise with a proper retraction and then re-advanced if resistance is encountered during placement. This is done to reduce laryngeal trauma. Once the ETT is passed, a bronchoscopic view did verify the placement.
Postoperatively, all surgical wounds healed uneventfully, and the patient showed no signs of facial paresis or other complications such as anterior open bite and Frey's syndrome. He was placed under strict physiotherapy exercise commencing 1 week postoperatively; however, the child did not adhere to the physical therapy under parental supervision. Although the patient could not attend to the hospital for periodical follow-ups due to socioeconomy and logistical constraints, home visits were extended and revealed that his maximum interincisal opening had reduced to 20 mm at 3rd month postoperatively.
Case 2
Patient information and clinical findings
A 55-year-old man known case of carcinoma of the left buccal mucosa was posted for partial mandibulectomy [Figure 2].
Figure 2: Left buccal region exposed and neck stiffness due to cervical spondylosisHis positron emission tomography-CT neck shows irregular metabolically active heterogeneously enhancing ulcers – the proliferative lesion is seen in the left buccal region with few prominent, bilateral level 2 cervical nodes seen with mild metabolic activity, larger right level 1 B node measures 10 mm × 8 mm. On the assessment of the airway, he was found to have a reduced mouth opening of <2 cm in length [Figure 3]. Mallampatti Grade 3 score. He has grossly reduced flexion and extension of the neck.
Figure 3: Ulceroproliferative growth in the left buccal cavity. (a) Growth in PET Scan. (b) Growth in the CT ScanAn X-ray revealed to be cervical spondylosis (C4–C5). History of chemotherapy and radiotherapy (+). Systemic examination revealed no abnormality. Biochemical investigations and ECG were normal. . The patient was taken up for surgery the next day with a plan of performing an awake fiberoptic intubation through right nostril and also the consent for tracheostomy also obtained in case of requirement. The patient was premedicated with tablet ranitidine 150 mg, tablet alprazolam 0.5 mg the previous night. After shifting to the operating room, he was connected to basic monitoring and venous access was established with an 18G cannula. Injection midazolam 2 mg, injection fentanyl 75 μg and dexmedetomidine 50 mcg over 15 min as the infusion was given. Flexible fiberoptic scope (FFS)-guided nasal intubation with 7.5 mm ETT done by “Spray as you go” method using 2% lignocaine, as the local condition precluded airway blocks. ET tube position was confirmed and fixed at 24 cm.
After establishing square waveform capnography, the patient was induced with injection propofol 2 mg/kg and paralyzed with an injection of vecuronium 4 mg; IV anesthesia was maintained with O2, N2O, and sevoflurane partial mandibulectomy was done. The patient was monitored for 24 h, and antiedemal measures were taken. The patient's vitals were stable and the patient was extubated the next day.
DiscussionAwake FOI and awake tracheostomy are the most common methods of managing a difficult airway depending on the site and nature of the lesion. Performing FOI in asleep patients can lead to serious morbidity, including “cannot intubate, cannot oxygenate” scenarios necessitating emergency surgical airways and even death, aspiration risk can be avoided[5] so awake FOI is mostly preferred and plays a vital role in difficult airway management, as it allows the anesthetist to have a safety management plan for the anticipated difficult airway and a rescue strategy for the unanticipated difficult airway.[6] Anesthetists should have a low threshold for using FOI when necessary, and if the decision is made to undertake it, serious consideration should be given to performing it in the awake patient. Awake FOI remains an invaluable choice for airway management in many patients, including those with difficult direct laryngoscopy and cervical spine injuries.
In children, fiberoptic bronchoscopy and intubation have the advantage of being easier, with shorter intubation time and continuous oxygenation and ventilation throughout the procedure. Children often become very sleepy, and perhaps apneic, with even small doses of pain medications. Unlike in adults, the airway in infants and children is wider at the top, above the glottis, and narrow below the larynx in the subglottic area. This funnel shape predisposes the child to a greater risk for airway obstruction from processes causing subglottic edema, such as croup or intubation trauma. Supraglottic dynamic obstructions in children are the first issue that should be ruled out when unanticipated difficulties with mask ventilation are noted. Optimizing head position in addition to traditional airway maneuvers, including a chin lift or jaw thrust, may improve ventilation in such pediatric airway complications. Small babies will desaturate very quickly if ventilation is interrupted mainly to a high metabolic rate. We describe guidelines to perform safe fiberoptic intubation, while maintaining spontaneous breathing throughout the procedure.
Fiberoptic intubation in pediatric patients with difficult airways could be a challenging task and the presence of craniofacial dysmorphisms presents additional challenges to tracheal intubation. It is more difficult to perform this procedure in pediatric patients than in adults mainly due to smaller airways in pediatric patients which make the manipulation of the fiberoptic more difficult since any small movement of the tip of the fiberoptic scope runs the risk of touching the mucosa of the nasopharynx/trachea. This will prevent good visualization of the airways and lead to perform back and fourth maneuvers of the fiberoptic scope to get a better image. While trying to work around this problem, children have higher rates of oxygen consumption, significantly shortening the period of apnea that can be safely tolerated. The anesthesiologist will have to interrupt the procedure to start ventilation and avoid severe desaturation of the patient. The advantage of minimal cervical movement during tracheal intubation with FOB had made the anesthetist always avid for its use. However, there are few reports debating its role in the emergency management of the airway after trauma.
Both cases were managed well with awake fibreoptic-guided nasal intubation. In case 1 –we did not try for intubating the laryngeal mask airway (ILMA) because it requires general anesthesia. It is not safe to induce in this patient without securing a definitive airway. Due to the pediatric age group airway blocks are not tried. The nasal route was preferred for intubation because surgeons required more working space. We cashed on it, as it was easier for the anesthesiologist as well.
Case 2
Was a postchemo and radiotherapy. Patient with buccal sinus and restricted mouth opening (+). Due to high bleeding tendencies through the sinus which may cause airway flooding and it is not safe to induce general anesthesia in this patient without securing the definite airway. So we did not go for ILMA or video laryngoscope. Cervical spondylosis may predispose the patient to fracture, we observed that awake fiberoptic nasal intubation was a better choice in patients with cervical spine abnormality to avoid neurological manipulations. In addition to helping in the intubation of the difficult airway, fiberoptic bronchoscope techniques are useful in a variety of other settings. They are often needed for airway examination for diagnostic and therapeutic purposes in thoracic surgery. The fiberoptic bronchoscope is the accepted standard for confirming the ideal positioning of double-lumen ETTs and has led to an increased margin of safety with the positioning of double-lumen tubes compared with auscultation and clamping maneuvers alone. The fiberoptic bronchoscope helps with the correct placement of bronchial blockers.
ConclusionRegarding intubating time, intubating attempts, hemodynamic pressor response, adverse effects, management of the difficult airway is a crucial patient safety issue, and FOI is a well-established and versatile tool for airway management in patients with known or suspected difficult airways or as a rescue technique (oxygen desaturation, sore throat, and hoarseness of voice) and postintubation neurological outcome.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Two important take-home messages from these two cases are
FFS-guided awake intubation is still a golden choice in some cases. Using new devices such as ILMA and video laryngoscopes may be very dangerous in these situations such as flooding of airway and neurological deficitWhenever a difficult intubation is anticipated, it is better to investigate completely to proceed with the procedure.Financial support and sponsorship
None.
Conflicts of interest
There are no conflicts of interest.
References
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