Abstract
Cervicofacial subcutaneous emphysema is an unusual complication following tonsil- lectomy. We present a 37-year-old male patient who, after receiving tonsillectomy, developed cervicofacial subcutaneous emphysema immediately following endotracheal extubation. Valsalva maneuvers evidenced by coughing and straining of the patient, and positive pressure ventilation by mask to alleviate laryngospasm in an emergency were believed to induce and exacerbate the emphysema. Fortunately, the patient was re-intubated and protected from further complication of pneumomediastinum or pneumothorax. The emphysema resolved 7 days later with conservative treatment, including broad-spectrum antibiotics and abstention from enteral intake. This case serves as a reminder that an unusual and unexpected complication can occur in a routine procedure. Methods to prevent this complication are discussed.
Keywords
postoperative complications; subcutaneous emphysema; tonsillectomy;
1. Introduction
Tonsillectomy is a common otolaryngological procedure in surgery. Common complications of tonsillectomy are well recognized and documented, including hemorrhage, damage to teeth, otalgia, odynophagia, throat infection, nausea, and vomiting.1 Nevertheless, subcutaneous emphysema or pneumomediastinum following tonsillectomy can occur and is rarely reported.2,3 Although it is usually benign and self-limiting, it can result in significant morbidity and mortality without proper recognition and management.4−7 We report a case of cervicofacial subcutaneous emphysema that developed immediately following endotracheal extubation after tonsillectomy. We hope that this incident will draw attention to this rare complication and thereby heighten awareness of this unpredictable event in anesthetic management.
2. Case Report
A 37-year-old, 78 kg man was scheduled for tonsillectomy and nasopharyngeal biopsy because of a granular tumor over the right tonsil with a bulging surface of the nasopharynx, which was identified during a health checkup. Preoperative systemic evaluation revealed no other abnormalities.
Anesthesia was induced intravenously with 375 mg thiopentone sodium (Pentothal®; Abbott S.p.A for Hospira Inc., Campoverde di Aprilia, Italy) and 0.15 mg fentanyl (Janssen Pharmaceutica N.V., Beerse, Belgium). The trachea was intubated with a 7.5 mm cuffed endotracheal tube after curarization with 50 mg rocuronium (Esmeron®; N.V. Organon, Oss, The Netherlands). The intubation was smooth and atraumatic. Anesthesia was maintained with 2−3% sevoflurane (Ultane®; Abbott Laboratories Ltd., Kent, UK) in an air and oxygen mixture under mechanical ventilation at pressure less than 20 cmH2O. Monitoring included noninvasive blood pressure measurement, electrocardiography, pulse oximetry, capnography and tidal volume measurement.
The surgical procedure and emergence from general anesthesia were unremarkable. The trachea was extubated smoothly after the patient became fully awake. There was no coughing or bucking during extubation. Supplemental oxygen was given via a facemask without positive pressure ventilation. However, after transferring the patient to a gurney, the patient developed forceful coughing with vigorous physical movement. Right-sided neck swelling localized to the submandibular region was found. Gross crepitus and softness were felt on palpation of the neck, which are diagnostic characteristics indicating subcutaneous emphysema. At the same time, plethysmography showed a fall in peripheral arterial saturation to 90%. Manual mask positive pressure ventilation with 100% oxygen and pressure up to 40 cmH2O was tried. The jaw was elevated to keep the airway patent without the aid of an oroor nasopharyngeal airway. However, the chest wall did not expand, while the neck swelling rapidly extended bilaterally from the cheeks to the infraclavicular region. Under the suspicion of laryngospasm and fearing extension of the emphysema to totally obstruct the upper airway, the patient was reanesthetized with 250 mg of thiopentone sodium followed by 80 mg of succinylcholine (Relaxin®; Shinlin Sinseng Pharmaceutical Co. Ltd., Taoyuan, Taiwan). The trachea was re-intubated laryngoscopically without difficulty. There was no upper airway swelling or compression. Re-inspection of the wound by an otolaryngologist did not reveal dehiscence, or any other mucosal tear in the pharynx or larynx.
The patient was transferred to the surgical intensive care unit. The trachea was extubated when the patient was fully awake. The patient was then returned to the general ward the following day. Chest and lateral view of neck radiography confirmed cervical subcutaneous emphysema (Figure 1) with retropharyngeal and parapharyngeal involvement (Figure 2). There was no pneumomediastinum or pneumothorax to complicate the cutaneous emphysema (Figure 1). Abstention from enteral intake was observed for 1 day and a prophylactic broad-spectrum antibiotic was given for 7 days to prevent oral bacterial contamination of the dissected cervicofacial planes. An oral analgesic was prescribed to treat the mild odynophagia and sore throat, which the patient complained of. Since the emphysema was no longer clinically evident on the third postoperative day, the patient was discharged. One week later at outpatient department follow-up, the emphysema had fully resolved. The patient remained well without any airway difficulties during the recovery period.
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3. Discussion
Cervicofacial subcutaneous emphysema is an unusual and rarely reported complication after surgery. It can be caused by surgical or anesthetic procedures, such as maxillofacial trauma,8 dental extraction,5,9 adenotonsillectomy,1,2,4−7,10,11 traumatic intubation,12,13 excessive positive pressure ventilation from ventilator malfunction14 or manual ventilation.4
Cervicofacial subcutaneous emphysema is the result of the entry of air or gas into the soft tissue planes of the cervicofacial region. Proposed causes of entry of air are: (1) mucosa disruption of the upper aerodigestive tract (descending route); (2) rupture of the marginal alveoli resulting from an excessive rise in intrapulmonary pressure11 (ascending route). Once the disruption of the mucosa occurs, any further increase of airway pressure, such as by the Valsalva maneuver and positive pressure ventilation, will facilitate the accumulation of air which dissects the cervicofacial planes.
In this patient, the tonsillectomy and nasopharyngeal biopsy created a rough and porous surface that allowed air to track through the superior constrictor pharyngeal muscle and easily find its way into the parapharyngeal and retropharyngeal spaces. Although the wound of the tonsillar bed was not dehiscent during re-inspection, sufficient weakness of the operated pharyngeal mucosa must have existed to allow air to enter the parapharyngeal space. Of note, mask positive pressure ventilation is not mandatory to relieve partial laryngospasm because it causes increased intrapharyngeal pressure, which can make the subcutaneous emphysema become more extensive, as happened in this case. Valsalva maneuvers, such as coughing, straining and vomiting, should also be prevented. Use of muscle relaxants in difficult airways is questionable in such extreme conditions. However, an ultra-short acting muscle relaxant, succinylcholine, was chosen to relieve laryngospasm and facilitate endotracheal tube intubation without further disruption of the vulnerable upper aerodigestive tract following tonsillectomy. The airway was protected from excessive positive pressure at the entry site of the aerodigestive tract and from further total obstruction of the airway because of emphysema. Fortunately, the peripheral desaturation was secondary to partial laryngospasm instead of emphysema-associated upper airway obstruction, which was relieved after succinylcholine administration. In severe cases with progressive deterioration, tracheostomy may be indicated.15 However, it is potentially difficult and even fatal.16 The emphysema did not further extend to the mediastinal and intrapleural spaces in our patient. Should this occur, the complicating pneumomediastinum or pneumothorax can be life-threatening with cardiopulmonary collapse.17
Importantly, other causes of rapid-onset swelling of the neck should be differentiated from cervicofacial subcutaneous emphysema, including hemorrhage, allergic reactions, and angioneurotic edema.18 Crepitus and softness of the subcutaneous tissues on palpation, and characteristic findings on radiography, are specific to the diagnosis of subcutaneous emphysema. Although it is usually self-limited and benign, perioperative care should focus on the evaluation of potential airway compression and complicating pneumomediastinum or pneumothorax to prevent supervening cardiopulmonary events. Caution must be exercised against ventilation with excessive positive pressure ventilation, either conveyed by endotracheal tube or by mask.
Management of this condition is generally conservative. Supplemental oxygen may facilitate absorption of nitrogen from air accumulating in the emphysematous cavity in a favorable downward concentration gradient, by which recovery from emphysema is hastened.11 Intravenous hydration and analgesia may be required where odynophagia is significant. Patients should refrain from strenuous exertion, coughing and straining until resolution of emphysema. Broad-spectrum antibiotics should be administered to prevent infectious complications from the migration of microorganisms from the oral cavity through any persisting mucosal defect of the pharynx or larynx.3
In conclusion, cervicofacial subcutaneous emphysema can complicate endotracheal extubation following tonsillectomy since tonsillectomy inevitably creates a weakness of the pharyngeal mucosa. To reduce these complications, care should be taken in airway management. Procedures to avoid mucosal disruption of the upper aerodigestive tract are of importance. Smooth emergence from anesthesia to avoid possible positive pressure ventilation, nausea, vomiting and coughing can help reduce the development of emphysema.