Gas flow during bronchoscopic ablation therapy causes gas emboli to the heart: a comparative animal study

Cerebral arterial air embolism after endobronchial electrocautery: a case report and review of the literature

Background

Endobronchial electrocautery is a common and safe therapeutic endoscopic treatment for malignant airway obstruction. Cerebral arterial air embolism (CAAE) is a rare but potentially fatal complication of endobronchial electrocautery.

Case presentation

We present the first case of cerebral arterial air embolism after endobronchial electrocautery. A 56-year-old male with a pulmonary tumour in the right upper lobe received repeated endobronchial electrocautery. During the procedure, he experienced unresponsiveness, hypoxemia and bradycardia, and he developed tetraplegia. Brain computed tomography showed several cerebral arterial air emboli with low-density spots in the right frontal lobe. He received hyperbaric oxygen therapy with almost full recovery, except for residual left-sided weakness.

Conclusions

General physicians should realize that CAAE may be a possible complication of endobronchial electrocautery. Several measures, including avoiding positive pressure, lowering ventilatory pressures if possible, avoiding advancing the bronchoscope to occlude the bronchus and using the non-contact technique, should be used to prevent this devastating complication.

Fiber optic CO2-laser induced emphysema of the supraglottis

Subcutaneous emphysema is a rare but well-defined surgical complication. However, emphysema of the supraglottic mucosa has not been described in the literature. We present a case of a 2-year-old male who suffered supraglottic emphysema secondary to fiber optic CO₂-laser use during laryngeal cleft repair. The patient required preemptive postoperative intubation; however, there were no long-lasting adverse effects at 6 and 12 weeks follow up. This report illustrates a rare CO₂-laser complication and describes its sequela.

New trends in interventional pulmonology

PURPOSE OF REVIEW

As the field of interventional pulmonology continues to expand and develop at a rapid pace, anesthesiologists are increasingly called upon to provide well tolerated anesthetic care during these procedures. These patients may not be candidates for surgical treatment and often have multiple comorbidities. It is important for anesthesiologists to familiarize themselves with these procedures and their associated risks and complications.

RECENT FINDINGS

The scope of the interventional pulmonologist's practice is varied and includes both diagnostic and therapeutic procedures. Bronchial thermoplasty is now offered as endoscopic treatment of severe asthma. Endobronchial lung volume reduction procedures are currently undergoing clinical trials and may become more commonplace. Interventional pulmonologists are performing medical thoracoscopy for the treatment and diagnosis of pleural disorders. Interventional radiologists are performing complex pulmonary procedures, often requiring anesthesia.

SUMMARY

The review summarizes the procedures now commonly performed by interventional pulmonologists and interventional radiologists. It discusses the anesthetic considerations for and common complications of these procedures to prepare anesthesiologists to safely care for these patients. Investigational techniques are also described.

Malignant central airway obstruction

This review comprehensively describes recent advances in the management of malignant central airway obstruction (CAO). Malignant CAO can be a dramatic and devastating manifestation of primary lung cancer or metastatic disease. A variety of diagnostic modalities are available to provide valuable information to plan a therapeutic intervention. Clinical heterogeneity in the presentation of malignant CAO provides opportunities to adapt and utilize endoscopic technology and tools in many ways. Mechanical debulking, thermal tools, cryotherapy and airway stents are methods and instruments used to rapidly restore airway patency. Delayed bronchoscopic methods, such as photodynamic therapy (PDT) and brachytherapy can also be utilized in specific non-emergent situations to establish airway patency. Although data regarding the success and complications of therapeutic interventions are retrospective and characterized by clinical and outcome measure variability, the symptoms of malignant CAO can often be successfully palliated. Assessment of risks and benefits of interventions in each individual patient during the decision-making process forms the critical foundation of the management of malignant CAO.

Hemodynamic Instability Following Airway Spray Cryotherapy

BACKGROUND

Spray cryotherapy (SCT) of airway lesions is used to effectively palliate respiratory symptoms related to airway obstruction, but significant intraoperative hemodynamic complications have been noted. We reviewed the experience at a single institution using SCT for the treatment of obstructive airway tumors.

METHODS

A retrospective review of a single institution experience with intraoperative and postoperative hemodynamic complications associated with SCT was performed. Descriptive statistics were performed.

RESULTS

Between June 2009 and April 2010, 34 treatment sessions were performed on 28 patients. Median age was 60 years (range, 15-88 years). Tumor characteristics were as follows: 13 primary lung cancers (43%), 11 pulmonary metastases (50%), 1 direct extension of an esophageal cancer (3%), and 2 benign pulmonary lesions (7%). Twenty-one tumors (75%) were distal to the carina; 14 (50%) were >95% occlusive. Median procedure length was 78 minutes (range, 15-176 minutes). Eleven sessions (31%) led to severe hypotension and/or bradycardia, with 2 patients requiring cardiopulmonary resuscitation. One patient died intraoperatively after cardiac arrest; a second patient was stable intraoperatively but died within 24 hours of SCT. Four patients required reintubation and short-term mechanical ventilation.

CONCLUSIONS

Unpredictable life-threatening hemodynamic instability can follow endobronchial SCT. We propose that the most likely cause is pulmonary venous gaseous emboli entering the right heart, the coronary arteries, and the systemic circulation. Although SCT may offer advantages over airway laser therapy (such as no risk of fire and rapid hemostasis), further study is needed to delineate the relative likelihood of therapeutic benefit versus catastrophic complications.

Vascular Air Embolism During Bronchoscopy Procedures- Incidence, Pathophysiology, Diagnosis, Management and Outcomes

Vascular air embolism (VAE) is a rare, but potentially fatal complication of invasive medical or surgical procedures. It is a very rare complication of bronchoscopy and is most frequently reported with therapeutic bronchoscopy with Argon plasma coagulation (APC) or neodymium-doped yttrium aluminum garnet (Nd-YAG) laser. Despite being rare, as a result of its high chance of mortality and morbidity, it is imperative that physicians have high clinical suspicion to allow for early recognition and treatment. In this article, we provide a concise review of the incidence, pathophysiology, diagnosis management and outcomes of air embolism during bronchoscopy procedures.

From electrocautery, balloon dilatation, neodymium-doped:yttrium-aluminum-garnet (Nd:YAG) laser to argon plasma coagulation and cryotherapy

Over the past decade, there has been significant advancement in the development/application of therapeutics in thoracic diseases. Ablation methods using heat or cold energy in the airway is safe and effective for treating complex airway disorders including malignant and non-malignant central airway obstruction (CAO) without limiting the impact of future definitive therapy. Timely and efficient use of endobronchial ablative therapies combined with mechanical debridement or stent placement results in immediate relief of dyspnea for CAO. Therapeutic modalities reviewed in this article including electrocautery, balloon dilation (BD), neodymium-doped:yttrium-aluminum-garnet (Nd:YAG) laser, argon plasma coagulation (APC), and cryotherapy are often combined to achieve the desired results. This review aims to provide a clinically oriented review of these technologies in the modern era of interventional pulmonology (IP).

Cerebral gas embolism from bronchoscopic argon plasma coagulation: a case report

Argon plasma coagulation (APC) is a common and safe bronchoscopic technique used in the management of obstructing lesions and hemorrhage in the central airways. Complications of bronchoscopic APC are uncommon and include hemorrhage, perforation and fire in the airways. While bronchoscopic APC has been reported to cause systemic gas embolization and associated cardiovascular collapse, we report a case of cerebral gas embolization that occurred during bronchoscopic APC and highlight underappreciated potential risk factors for its occurrence.

Advances in interventional pulmonology

PURPOSE OF REVIEW

Interventional pulmonology is a rapidly expanding field offering less invasive therapeutic procedures for significant pulmonary problems. Many of the therapies may be new for the anesthesiologist. Although less invasive than surgery, some of these procedures will carry significant risks and complications. The team approach by anesthesiologist and pulmonologist is key to the success of these procedures.

RECENT FINDINGS

Many modalities for central airway obstruction have emerged, including the expanding application of airway stenting procedures. Diagnostic bronchoscopy with ultrasound guidance promises great advances in lung cancer staging. New bronchoscopic treatments of asthma and emphysema are actively under investigation. Advances in anesthetic agents and techniques for interventional pulmonology procedures have also occurred.

SUMMARY

This review is intended to familiarize the anesthesiologist with current and rising therapeutic modalities for pulmonary disease. Knowledge of interventional pulmonology facilitates planning and preparation for well tolerated and effective procedures.