How should postoperative surgical subcutaneous emphysema presenting with neck or chest wall swelling and crepitus be evaluated and treated?

Evaluation and Management of Postoperative Surgical Subcutaneous Emphysema

Immediate Clinical Assessment

When postoperative subcutaneous emphysema presents with neck or chest wall swelling and crepitus, immediately assess for airway compromise by examining for stridor, accessory muscle use, tracheal tug, or chest wall recession, as this may indicate impending airway obstruction requiring urgent intervention. 1

Critical Initial Steps

• Position the patient upright and administer high-flow humidified oxygen immediately to optimize venous drainage and oxygenation 1
• Never ignore a patient complaining of dyspnea or difficulty breathing, even when objective signs are absent, as pharyngeal and esophageal injuries may be present without obvious clinical findings in up to 50% of cases 1
• Utilize waveform capnography when available to detect early airway obstruction, as pulse oximetry alone is insufficient for monitoring ventilation 1, 2
• Monitor vital signs continuously including respiratory rate, heart rate, blood pressure, oxygen saturation, temperature, and level of consciousness 1, 2

Diagnostic Imaging Approach

Obtain immediate chest radiography as the first-line imaging study to identify pneumothorax, pneumomediastinum, or other thoracic injuries that are the source of subcutaneous air 1, 2

Imaging Algorithm

• Radiographs effectively demonstrate soft-tissue gas, airway competency, and fractures but have limited sensitivity for deep fascial gas 1
• CT is the most sensitive modality for detecting soft-tissue gas and can delineate extent and compartmental location when radiographs are equivocal or clinical concern is high 1
• MRI is less sensitive than CT for detecting soft-tissue gas and should not be used as a first-line study 1

Identifying the Underlying Cause

Check for Iatrogenic Sources First

If a chest tube is already in place, immediately check whether it is clamped, kinked, blocked, or malpositioned, as these are the most common iatrogenic causes of worsening subcutaneous emphysema 3, 4, 2

• Never clamp a bubbling chest tube, as this converts a simple pneumothorax into a life-threatening tension pneumothorax and forces air into subcutaneous tissues 3, 4, 2
• Unclamp any clamped tube immediately if the patient develops breathlessness or progressive emphysema 3, 4
• Verify chest tube patency by flushing with 20-50ml normal saline 3

Assess for Serious Underlying Injuries

Evaluate for mediastinitis, which presents with severe sore throat, deep cervical pain, chest pain, dysphagia, painful swallowing, fever, and crepitus, particularly after difficult intubation or airway manipulation 1, 2

• Recognize that airway trauma most commonly involves the larynx after routine intubation and the pharynx/esophagus after difficult intubation 1
• Pneumothorax, pneumomediastinum, or surgical emphysema are present in only 50% of pharyngeal and esophageal injuries, so maintain high clinical suspicion even with negative imaging 1, 2

Treatment Based on Severity

For Mild to Moderate Emphysema Without Airway Compromise

Most cases are cosmetically concerning but clinically benign and will subside within days without specific intervention 3, 4

• Continue close observation with serial examinations to detect progression 2
• Maintain the patient nil per os (fasted) when any airway compromise is present, as laryngeal competence may be impaired despite full consciousness 1, 2
• Encourage deep breaths and coughing to clear secretions 1

For Pneumothorax Requiring Intervention

Insert a small-bore chest tube (10-14F) for pneumothorax, as there is no evidence that larger tubes (20-24F) are more effective 2

• Use strict aseptic technique during insertion to minimize the 1% risk of empyema 3
• Obtain a chest radiograph after insertion to verify position and rule out iatrogenic complications 3
• Keep the underwater seal drainage system below the patient's chest level at all times 3
• Ensure patients on suction are cared for in settings with specialist nursing expertise 2

For Severe Emphysema With Airway Compromise

Rarely, extensive subcutaneous emphysema causes acute airway obstruction or thoracic compression requiring emergency intervention including tracheostomy, skin decompression, or large-bore subcutaneous drains 3, 5

• Have a difficult airway trolley immediately available with appropriate equipment 1
• An appropriately skilled anesthetist must be immediately available for potential emergency airway management 1
• Consider early rapid-sequence induction if airway obstruction is imminent 5

Critical Pitfalls to Avoid

• Never clamp a chest tube that is bubbling, as this is the primary cause of tension pneumothorax and worsening emphysema 3, 4, 2
• Do not rely solely on pulse oximetry, as it is not designed to monitor ventilation and can give incorrect readings 1
• Avoid dismissing patient complaints of breathing difficulty when objective signs are minimal, as serious injuries may be occult 1
• Do not use trocars or substantial force during chest tube insertion, as this significantly increases the risk of organ injury 3

Ongoing Management and Monitoring

Patients should remain in a monitored setting (recovery or critical care) until airway reflexes have fully returned and they are physiologically stable 1

• Maintain continuous standard monitoring including capnography when available 1
• Factors that impede venous drainage should be avoided 1
• For patients with obstructive sleep apnea, ensure their CPAP device is available for use in recovery and on the ward 1
• Inform patients about symptoms of mediastinitis and advise them to seek immediate medical attention if these develop 1