Mask Induction for an Intellectually Disabled Patient With Congenital Infiltrating Lipomatosis of the Face

Abstract

Airway management for patients with craniofacial disorders poses many challenges. Congenital infiltrating lipomatosis of the face (CILF) is an extremely rare disorder in which mature lipocytes invade adjacent tissues in the head and neck. The manifestations are typically unilateral, often with associated hypertrophy of both the hard and soft tissues of the face. This is a case report regarding the anesthetic management for a 5-year-old intellectually disabled female with CILF involving the right side of her face who underwent a successful intubated general anesthetic for dental treatment. Awake fiber-optic intubations are recommended and routinely used for patients with suspected or confirmed difficult airways. In this case, substantial distortion of the normal facial anatomy was observed clinically with noted hypertrophy of the right maxilla, mandible, and right side of the tongue. Further complicating matters was the patient's inability to fully cooperate because of her intellectual disability, precluding the option of an awake fiber-optic intubation. To secure the airway following mask induction of anesthesia, spontaneous ventilation was carefully maintained using sevoflurane, nitrous oxide, and oxygen combined with the application of a nasopharyngeal airway. Despite compression of the oral cavity and upper pharyngeal space by the hypertrophic tissues due to CILF, the space in and around the glottis was preserved. Intubation was completed easily with the use of a fiber-optic scope without any serious complications.

Congenital infiltrating lipomatosis of the face (CILF) is a rare disorder in which mature lipocytes invade adjacent tissues in the head and neck. This disease was first described in 1983,¹ but the etiology remains still unknown. Critical features of CILF include poorly circumscribed proliferation of mature adipose tissue leading to the gradual enlargement of the affected side of the face and facial asymmetry, as well as hypertrophy of the facial bones, macroglossia, and proliferation of the parotid gland on the affected side.² A previous case report and systematic literature review found 59 patients who presented with a congenital unilateral facial soft-tissue mass that was nonpulsatile, noncompressible, and ill-defined. Facial asymmetry was reported in 100% of those cases. In addition, 69% of the cases demonstrated ipsilateral hypertrophy of the underlying facial skeleton, of which 67% involved the zygoma, 64% the maxilla, and 31% the mandible, respectively. Furthermore, infiltration of adipose tissue into the surrounding tissues was noted, affecting the facial muscles in 41% and the parotid gland in 37% of the 59 cases.² The histological features of CILF resemble well-differentiated liposarcoma, which may lead to confusion during histopathologic analysis and rendering of an inaccurate diagnosis.³ As such, the diagnosis of CILF is also based on the patient's medical history, clinical manifestations, and imaging features. Ultrasound, computed tomography, and magnetic resonance imaging may be useful in determining the extent of adipose tissue infiltration of the surrounding tissues. With regard to anesthesia management, the resulting enlargement and asymmetry of the facial complex can lead to obstruction of the upper airway along with an increased risk for ventilation and intubation difficulties.

Additional complicating factors in this case were the comorbidity of intellectual disability combined with the young age of the patient. Dental treatment under general anesthesia is often used for these patients, as children with intellectual disabilities are usually too uncooperative for routine dental procedures to be performed in the traditional dental setting. In addition, they can often have rampant caries resulting from the combination of intellectual disability and young age, which can make adequate daily oral hygiene quite difficult. In this case, the added complication of the patient's facial malformations likely further increased the difficulties associated with maintaining adequate oral hygiene.

Awake fiber-optic nasotracheal intubation is a useful technique for patients with a suspected or difficult airway, but such an approach requires cooperation from the patient. In the case of a young pediatric patient with an intellectual disability and CILF, the concern for a difficult airway must be balanced with the patient's uncooperative attitude. As such, an awake fiber-optic intubation is unlikely to be successful because of the lack of cooperation. These factors required the development and use of alternative approaches to safely induce general anesthesia and facilitate securing the patient's airway.

Sevoflurane, with or without nitrous oxide, is often used for mask induction of general anesthesia, which can be quite useful for inducing pediatric patients and/or patients with intellectual disabilities. In addition, this technique permits maintenance and assessment of spontaneous ventilation, which can be useful for patients with potential or suspected difficult airways. Therefore, the anesthetic plan developed for this patient included inhalational mask induction with sevoflurane, nitrous oxide, and oxygen combined with a fiber-optic intubation once the patient was sufficiently anesthetized. Additional plans included obtaining intravenous access after induction and securing the airway with the use of either a nasal endotracheal tube if possible or an oral endotracheal tube if not.

CASE REPORT

The patient was a 5-year-old girl (height 115.9 cm, weight 24 kg, body mass index 17.9 kg/m²) with a history of intellectual disability, CILF, and epileptic seizures. The patient's seizures reportedly occurred rarely and were well controlled with levetiracetam (250 mg, twice daily), which was continued perioperatively. The patient had no known drug allergies and had undergone intubated general anesthesia without complications twice in the past. Because of her intellectual disability, she was unable to speak meaningful sentences except for a few words. The patient was able to ambulate; however, she demonstrated an altered gait with short steps and a clumsy swaying motion.

Immediately after birth, the patient was noted to have a diffuse swelling involving her right cheek, which increased substantially over time, evolving into multiple soft masses on the right side of her face/cheek. Subsequent biopsy and histopathologic evaluation produced a diagnosis of facial lipomatosis, and she underwent surgery twice to reduce the volume of the mass, at 1 and 3 years of age. However, the mass continued to gradually expand, deforming and negatively affecting the patient's normal skeletal growth in the right cheek area (Figure 1). The computed tomography scan obtained preoperatively demonstrated that the soft-tissue mass in the right cheek had the same isodense appearance as the subcutaneous fat tissue (Figure 2). The mass measured 166 × 106 × 63 mm³ in size, extending from the inferior edge of the infraorbital rim to the mandible and the infratemporal region. The tissue mass occupied large aspects of the right cheek, and the patient's upper airway, including the pharynx, appeared to be affected. In addition, clinical assessment of the patient's airway, including maximum interincisal distance and Mallampati classification, was difficult to perform as the patient was uncooperative because of her intellectual disability. However, there were no signs of difficulty in breathing. The patient's mother suspected she had several teeth with dental caries, which was later confirmed by the pediatric dentist. She was subsequently scheduled for restorative treatment of 4 teeth along with preventive dental treatment to be performed with the use of general anesthesia.

Figure 1.

A 5-year-old female with a substantial soft tissue mass in the right cheek.

Figure 2.

Preoperative computed tomography image showing lipomatous infiltration of the right side of the face with the same isodense appearance as the subcutaneous fat.

During the preoperative anesthetic evaluation, routine electrocardiogram demonstrated sinus rhythm, and no abnormal findings were noted on the routine preoperative chest radiograph. Routine preoperative blood tests (complete blood count and serum biochemistry panel) were also within normal limits. At this health care facility, these tests are performed routinely for all cases. Preoperative vital signs obtained during the evaluation on the day before surgery included a heart rate of 116 beats/min, blood pressure of 106/50 mmHg, and a peripheral oxygen saturation (SpO₂) of 98% in room air.

On the day of surgery, adherence to nil per os guidelines was confirmed, and no premedication was given before the patient entered the operating room accompanied by her mother. Once in the operation room, the patient strongly refused to lay down on the operating table. Therefore, mask induction of anesthesia was started with the patient in the sitting position via inhalation of sevoflurane (3–5%) plus nitrous oxide (6 L/min) and oxygen (3 L/min) after placement of the pulse oximeter and initiating capnography monitoring. After loss of consciousness, the patient was placed supine on the operating table, her mother was escorted from the room, and the remaining standard anesthesia monitors were placed consisting of an electrocardiogram, noninvasive blood pressure cuff, bispectral index, and temperature probe. Peripheral intravenous access was obtained with a 22G catheter placed in the dorsum of the left hand. Following mask induction, the patient's vital signs were heart rate 100 beats/min, blood pressure 92/45 mmHg, SpO₂ 100%, and bispectral index 36 (spectral edge frequency: 14–20 Hz, signal quality index: 95%). A nasopharyngeal airway was placed in the right nares to ease ventilation. Assisted ventilation using the mask and nasal airway combination was easy, and spontaneous breathing was maintained without signs of obstruction. While ensuring continued maintenance of spontaneous ventilation, midazolam (2 mg) and atropine (150 μg) were administered intravenously, and a continuous infusion of remifentanil (0.25 μg/kg/min) was started. Throughout the entire induction period, the patient's respiratory rate was 24–26 bpm and SpO₂ was 98–99%.

To suppress adverse reflexes, including cough reflex during intubation, topical anesthesia was performed by spraying 2% lidocaine (1 mL) around the vocal cords and into the trachea.

The patient was nasotracheally intubated through the left nares using a 5.0-mm cuffed spiral-wound tracheal tube (Mallinckrodt, St Louis, Mo) using a flexible fiber-optic scope (Pentax FB-15, HOYA, Tokyo, Japan) and without any muscle relaxants. The patient remained spontaneously ventilating with an SpO₂ maintained above 97% until successful intubation. It was noted that the soft tissues in the oral cavity were compressed to the unaffected healthy left side by the hypertrophied tissues on the right, including the tongue (Figure 3). However, space in and around the glottis and pharynx, including hypopharynx, was well preserved. There was no noted bleeding, and the glottic structures were easily visualized with the fiber-optic scope. Successful intubation was confirmed by auscultation of the left and right lung sounds and use of capnography, after which rocuronium (20 mg) was administered intravenously and mechanical ventilation was initiated. A gastric tube and a Foley catheter were inserted, respectively. Anesthesia was maintained with isoflurane (1.5–1.7%) combined with air (1.4 L/min) and oxygen (0.6 L/min). Blood pressure was maintained at 90–100/32–48 mmHg, heart rate was 105–113 bpm, end-tidal carbon dioxide was 37–39 mmHg, and BIS was maintained at 42–60 with spectral edge frequency 12–18 Hz and signal quality index 95%.

Figure 3.

Enlarged oral soft tissues and tongue.

Dental treatment was completed without any surgical or anesthetic complications in 2 hours 48 minutes with the use of 0.4 mL of local anesthetic containing 12 mg of prilocaine hydrochloride and 0.012 units of felypressin via infiltration anesthesia. The patient received a total of 560 mL lactated Ringer's solution containing 1% glucose. Total urine output was 110 mL, and blood loss was minimal. The tracheal tube was suctioned using an endotracheal suction catheter after the end of the dental treatment and the isoflurane discontinued after confirming that there were no ventilatory problems after performing a cuff leak test. No reversal of the neuromuscular relaxant was deemed necessary, as the train-of-four ratio was confirmed to be 100%. The patient was extubated awake 12 minutes later without difficulty after confirming responsiveness and adequacy of spontaneous ventilation. End-tidal isoflurane was noted to be 0.3% at time of extubation. After extubation, the patient's vital signs remained stable, and she was drowsy but could open her eyes upon command. Throughout the immediate recovery period there were no apparent complications, and she was transferred to the ward, where she remained until she fully recovered back to baseline approximately 2 hours later. There were no significant postoperative changes or complications noted, and she was discharged without incident the next day.

DISCUSSION

CILF is a congenital, nonhereditary disease, which was first described by Slavin et al¹ in 1983. CILF is a very rare disorder characterized by a collection of lipocytes with ill-defined borders that infiltrate surrounding muscles and soft tissues. The exact etiology of CILF remains unknown. The current pathogenic theory involves a somatic mutation in the PIK3CA gene in the affected tissues, which is also detected in cancers and affected tissues from other nonheritable and overgrowth disorders. PIK3, encoded by PIK3CA, plays a crucial role in regulating cell proliferation, adhesion, survival, and motility.² The tissue proliferation caused by these abnormalities could also occur in the pharynx and oral cavity, causing compression of the upper airway, which might lead to difficulty with ventilation and/or intubation during anesthesia.

Anesthetic management of the difficult airway is a challenge, as it might lead to life-threatening complications. The difficult airway could be categorized as difficulty with ventilation and/or intubation. It has been reported that 1–18% of patients have a difficult airway.⁴ Situations in which the patient cannot be intubated and ventilated are rare, but these are major causes of death during anesthesia. In Japan, a survey by the Japanese Society of Anesthesiologists showed that the main cause of cardiac arrest related to anesthesia is difficulties with the airway (44%) and ventilation (13%).⁵ In the case of a suspected difficult airway, an “awake” approach should be considered. Awake intubation using a flexible fiber-optic scope is a safe technique for cooperative patients with a suspected or confirmed difficult airway.^6,7 However, this technique may be uncomfortable for patients and may likely be considered an unacceptable option for uncooperative patients.

In the case of this patient, it was anticipated that mask ventilation and/or tracheal intubation might be very difficult because of the extent of the patient's facial mass in addition to the accompanying hypertrophy/deformity of her facial bones and macroglossia on the affected right side. In addition, this patient was 5 years old and had an intellectual disability that further complicated matters because of lack of cooperation. Therefore, the developed anesthetic plan consisted of using a flexible fiber-optic scope to assist with intubation while maintaining spontaneous ventilation under general anesthesia following mask induction with sevoflurane, nitrous oxide, and oxygen.

Sevoflurane is an inhalational anesthetic that enables smooth and rapid mask inductions, as it has a blood gas solubility of 0.69 and is nonirritating to the airway. Therefore, these properties make sevoflurane an ideal agent for inhalational mask induction in pediatric patients. In addition, careful induction with sevoflurane may be reversed quickly if any problem arises regarding airway management.⁸ On the other hand, inhalational induction could have problems such as breath-holding and laryngospasm. During induction of anesthesia, the high concentration (>7%) and low solubility of sevoflurane can rapidly produce deep levels of anesthesia and may lead to respiratory depression, apnea, and sudden loss of airway patency.⁹ In the awake state, the upper airway is maintained by physiologic reflexes and neural activity of the upper airway musculature.¹⁰ In the unconscious condition, neuromuscular control of the upper airway musculature is reduced. Many anesthetic agents can further inhibit neural activity of the upper airway muscles, thereby causing the upper airway to narrow and collapse.¹¹ In this case, patency of the upper airway was further maintained by inserting a nasopharyngeal airway, which was useful in the maintenance of spontaneous ventilation. Preparations were made to use an oropharyngeal airway and/or a laryngeal mask airway if the nasopharyngeal airway could not be inserted successfully.

In this patient, the facial mass could have caused obstruction of the upper airway, which might have led to acute respiratory distress. However, the patient's airway was easily managed using the nasopharyngeal airway, and sevoflurane maintained at 3–5% during inhalational mask induction. There were no instances of breath-holding or coughing throughout the entire induction, use of the fiber-optic scope, and subsequent intubation. In addition, the patient maintained spontaneous ventilation the entire time, illustrating that the proper depth of anesthesia could be achieved without loss of the airway. The use of topical local anesthesia to further reduce the risk of coughing during intubation was likely a critical step. If spontaneous ventilation was not maintained or was suspect, the plan was to stop the case by discontinuing the inhalational anesthetics and waking the patient up emergently. At that point, further steps would be taken in accordance with the Practice Guidelines for Management of the Difficult Airway of the American Society of Anesthesiologists.¹²

CONCLUSION

CILF is a collection of lipocytes with ill-defined borders that infiltrates surrounding muscles and soft tissues of the facial complex with the potential to affect the pharynx and oral cavity, causing compression of the upper airway. Such implications are especially critical for anesthesiologists as they can lead to difficulty with ventilation and/or intubation during anesthesia. Therefore, utilization of a safe induction technique, such as an awake fiber-optic intubation, is typically required. However, that approach may not be an option for many uncooperative patients, for example, those with an intellectual disability or pediatric patients. In those select patient groups, it is often necessary to devise alternative approaches, such as mask induction followed by intubation guided with a flexible fiber-optic scope. Other key aspects include preparation for a difficult airway and selective use of airway adjuncts.

In conclusion, careful mask induction while maintaining spontaneous ventilation using sevoflurane, nitrous oxide, and oxygen plus the use of a nasopharyngeal airway facilitated acceptable intubating conditions with the use of a flexible fiber-optic scope. This technique may be useful for noncooperative patients with a suspected or confirmed difficult airway.