Anaesthesia and tracheobronchial stenting for central airway obstruction in adults

Risk Factors for Desaturation in Anesthetic Management During Airway Stenting

Airway stenting involves a stent being inserted into a stenotic site in the airway. In patients with airway stenosis, the airway is the surgical field; therefore, anesthetic management is challenging, and avoiding hypoxia is important. Limited information is available on the anesthetic management of airway stenting. Risk factors for oxygen desaturation during airway stenting remain unknown. The present study was conducted to retrospectively examine patients who underwent airway stenting during a specific period and identify risk factors associated with oxygen desaturation. We performed univariate and multivariate analyses. The main evaluation items in a multivariate analysis were risk factors for desaturation (SpO2 ≤ 90%). Body mass index, preoperative orthopnea, the stenotic site of the airway, and severity of stenosis were selected for clinical usefulness. We analyzed 302 patients who underwent airway stenting at our hospital between July 2011 and June 2014 under general anesthesia with controlled ventilation. Total intravenous anesthesia with propofol target-controlled infusion and remifentanil was performed. Clinical data were extracted from electronic anesthetic records. The incidence of desaturation (SpO2 ≤ 90%) was 18.5% (56 out of 302 cases). Preoperative orthopnea (OR, 3.06)and stenosis distal to the bronchus (OR, 3.31) were identified as risk factors for desaturation in a multivariate analysis. We herein identified risk factors for desaturation during airway stenting. Anesthetic plans need to be carefully considered for patients with these risk factors.

Anesthetic management in a patient with severe tracheal stenosis by monitoring oxygen reserve index

Background

General anesthesia for tracheal stenting is challenging because of difficult ventilation and accompanying hypoxia. We report the use of oxygen reserve index (ORi™) during tracheal stenting.

Case presentation

Cauterization of an intratracheal tumor and tracheal stenting was scheduled in a patient. ORi decreased from 0.3 to 0.2 after starting cauterization using a flexible bronchoscope through a tracheal tube with 28% oxygen, while SpO₂ was maintained at 100%. ORi further decreased to 0, followed by a decrease of SpO₂ < 90%, and surgery was interrupted. SpO₂ was increased shortly after increasing FiO₂ to 1.0, but ORi remained 0 when surgery was resumed; it was increased after completion of cauterization. Both ORi and SpO₂ were maintained above 0.4 and 98%, respectively, during tracheal stenting through a rigid bronchoscope under intrapulmonary percussive ventilation.

Conclusion

ORi was useful for predicting a decrease of SpO₂ under general anesthesia for tracheal stenting.

Intervention to severe lower trachea obstruction supported by extracorporeal membrane oxygenation in a human immunodeficiency virus patient: A case report and literature review

Here we reported a case, male, 33 years old, diagnosed with human immunodeficiency virus (HIV) infection 5 months ago, but he didn’t take antiretroviral drugs regularly. He was admitted to intensive care unit emergently due to hypoxemia, hypercapnia, and hypotension. CT showed severe lower trachea obstruction caused by soft tissue. After rapid bedside assessment, the patient was considered to need endotracheal operation, but he couldn‘t tolerate intubation and mechanical ventilation. Extracorporeal membrane oxygenation (ECMO) was used. Hemodynamics improved significantly along with rehydration and low-dose vasoactive drugs. Subsequently, the patient underwent rigid bronchoscopy, airway tumor resection and Y-type silicone stent implantation. Postoperatively protective endotracheal intubation and mechanical ventilation was followed. ECMO was weaned off after the operation, and endotracheal cannula was removed 6 h later. The pathological examination of excisional tissue showed lung squamous cell carcinoma. Finally, the patient was discharged safely and went to local hospital for further treatment. From this case, we conclude that ECMO could play a key role for those who need endotracheal surgery while cannot endure conventional intubation and mechanical ventilation.

The intersection of bronchoscopy and extracorporeal membrane oxygenation

Central airway obstruction (CAO), which results from malignant, benign or iatrogenic etiologies, causes significant morbidity and mortality and can be seen in both the pediatric and adult patient population. Patients frequently present to the hospital with dyspnea, stridor, and respiratory distress, indicating impending respiratory failure. Heliox is used to help alleviate symptoms while procedural planning takes place. A multidisciplinary approach to airway management is often needed. Interventional pulmonologists treat CAO with rigid of flexible bronchoscopy in order to deliver therapeutic interventions under general anesthesia. In severe CAO where there is concern for total loss of the airway creating a life-threatening situation for the patient during procedural intervention, short term extracorporeal membrane oxygenation or ECMO has been successfully reported in the literature to provide ventilation and oxygenation support throughout the procedure. Venoarterial ECMO can be used to augment cardiac output in cases of central tumors with cardiac involvement. ECMO can also be used for the removal of tracheal stents when there is a concern that ventilation will be interrupted for a prolonged period of time. ECMO has also been reported as a salvage measure for patients with life threatening hemoptysis until more definitive interventions can be performed. Short term ECMO cannulation can be used with limited associated morbidity and a heparin-free approach can be pursued when there is a concern for bleeding. We will briefly review the anesthetic considerations in CAO as well as review cases of CAO where ECMO was employed to safely alleviate the airway compromise.

Near ideal anesthetic technique for tracheal stenting in central airway obstruction with dexmedetomidine-ketamine infusion: a case report

Central airway obstruction presents as an emergency with dyspnea and stridor. Anesthetic management of rigid bronchoscopy-guided tracheal stenting is highly stimulating procedure requiring general anesthesia. But it may lead to life threatening airway obstruction and cardiovascular collapse after induction. Total intravenous anesthesia based on propofol-remifentanil is an optimal anesthetic technique, but remifentanil is not available in many countries. Although dexmedetomidine-ketamine has been used for procedural sedation, its use for rigid bronchoscopy in the setting of central airway obstruction has not been described in literature. We describe near ideal anesthetic technique for management of central airway obstruction using dexmedetomidine-ketamine combination.

High frequency jet ventilation at the distal end of tracheostenosis during flexible bronchoscopic resection of large intratracheal tumor: Case series

INTRODUCTION

Resection of a large intratracheal tumor with severe obstruction via flexible bronchoscope remains a formidable challenge to anesthesiologists. Many artificial airways positioned proximal to tracheal obstruction can not ensure adequate oxygen supply. How to ensure effective gas exchange is crucial to the anesthetic management.

PATIENT CONCERNS

Five patients of intratracheal tumor occupying 70% to 85% of the tracheal lumen were scheduled for tumor resection via flexible bronchoscope.

DIAGNOSIS

The patients were diagnosed with intratracheal tumor based on their symptoms, radiographic findings and tracheoscopy.

INTERVENTIONS

We describe a technique of high frequency jet ventilation (HFJV) using an endobronchial suction catheter distal to tracheostenosis during the surgery, which ensured the good supply of oxygen. We applied general anesthesia with preserved spontaneous breathing. A comprehensive anesthesia protocol that emphasizes bilateral superior laryngeal nerve (SLN) block and sufficient topical anesthesia. An endobronchial suction catheter was introduced transnasally into the trachea and then advanced through the tracheostenosis with the tip proximal to the carina under direct vision with the aid of fiber bronchoscope. HFJV was then performed through the suction catheter.

OUTCOMES

The SPO2 maintained above 97% during the surgery. Carbon dioxide retention was alleviated obviously when adequate patency of the trachea lumen achieved about 30 min after the beginning of surgery. HFJV was ceased and all patients had satisfactory spontaneous breathing at the end of the procedure.

CONCLUSION

HFJV at the distal end of tracheostenosis is a suitable ventilation strategy during flexible bronchoscopic resection of a large intratracheal tumor.

Retrievable covered metallic segmented Y airway stent for gastrorespiratory fistula of carina or main bronchi

OBJECTIVE

To evaluate the feasibility of new retrievable covered metallic segmented Y airway stents modified with 3-dimensional (3D) printing for gastrorespiratory fistula involving carina or main bronchi.

METHODS

We designed a new retrievable covered metallic segmented Y airway stent to fit the anatomical characteristics of the carina region in individual patients. All stents were individually customized based on a 3D-printed mold. Six patients with gastrorespiratory fistula and aspiration pneumonia after esophagectomy underwent the stent implantation. The stents were retrieved when the fistula was cured or stent-related complications occurred.

RESULTS

Seven Y stents were successfully implanted and removed in 6 patients. All stents expanded well, and the fistulas were completely sealed. Aspiration pneumonia was controlled in 6 patients. The median Karnofsky Performance Status scores significantly improved after stenting compared with those before stent implantation (P = .024). Sputum retention was the most common complication after stenting and was treated with aspiration under bronchoscopy (33.33%). Excessive granulation tissue proliferation was found in 1 patient (16.7%) and was treated with cryotherapy. The indwelling time of the stent was 64 days (interquartile range, 52-69 days). After stent removal, bronchoscopy, gastroscopy, and computed tomography of the chest showed cured fistulas in all patients, and no stents showed fractures.

CONCLUSIONS

Retrievable covered metallic segmented Y airway stents modified with 3D printing appear to be feasible for the treatment of gastrorespiratory fistula involving carina or main bronchi.

Pulmonary Artery Stent Graft Repair of Bronchovascular Fistula

Endobronchial stenting is a well-established palliative approach in lung cancer patients with airway obstruction secondary to tumor burden. However endobronchial stenting can be complicated by stent erosion into adjacent vessels. Although most cases of endobronchial stent-related hemoptysis can be treated by stent revision and/or surgical resection, here we present a case managed by endovascular pulmonary arterial stent placement as a last resort option in the management of an iatrogenic bronchovascular fistula in a nonsurgical candidate.

Evaluation of Safety and Short-term Outcomes of Therapeutic Rigid Bronchoscopy Using Total Intravenous Anesthesia and Spontaneous Assisted Ventilation

BACKGROUND

There is a paucity of published data regarding the optimal type of anesthesia and ventilation strategies during rigid bronchoscopy.

OBJECTIVE

The aim of our study is to report the procedural and anesthesia-related complications with rigid bronchoscopy using total intravenous anesthesia and spontaneous assisted ventilation.

METHODS

A retrospective review of patients undergoing therapeutic rigid bronchoscopy at the University of Chicago between October 2012 and December 2014 was performed. Data were recorded relating to patients' demographics, comorbidities, type of anesthesia, need for neuromuscular blockade (NMB), intraoperative hypoxemia, hypotension, perioperative adverse events, and mortality.

RESULTS

Fifty-five patients underwent 79 rigid bronchoscopy procedures; 90% were performed for malignant disease and 90% of patients had an American Society of Anesthesiologists (ASA) class III or IV. The majority (76%) did not require use of NMB. The most common adverse events were intraoperative hypoxemia (67%) and hypotension (77%). Major bleeding and postoperative respiratory failure occurred in 3.8 and 5.1% of procedures, respectively. There was no intraoperative mortality or cardiac dysrhythmias. The 30-day mortality was 7.6% and was associated with older age, inpatient status, congestive heart failure, home oxygen use, and procedural duration. Intraoperative hypoxemia, hypotension, and ASA class were not associated with 30-day mortality. The majority (94%) of patients were discharged home. The use of NMB did not impact outcomes.

CONCLUSIONS

This study suggests that therapeutic rigid bronchoscopy can be safely performed with total intravenous anesthesia and spontaneous assisted ventilation in patients with central airway obstruction, significant comorbidities, and a high ASA class. The only significant modifiable variable predicting the 30-day mortality was the duration of the procedure.

Partnership with Interventional Pulmonologist: An Anesthesiologist's Perspective

Via the emergence of new bronchoscopic technologies and techniques, there is enormous growth in the number of procedures being performed in nonoperating room settings. This, coupled with a greater focus from the Centers for Medicare and Medicaid Services for mandated anesthesiology oversight of procedural sedation for bronchoscopy by the pulmonologists has led to a more frequent working partnership between interventional pulmonologists and anesthesiologists. This article offers the interventional pulmonologist insight into how the anesthesiologist thinks and approaches anesthetic care delivery.

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.

Thoracic oesophageal cancer as a cause of stridor: a literature review

An 83-year-old woman, with a background of treated squamous cell oesophageal cancer, presented with a 3-week history of stridor. Of note, the patient had no risk factors for oesophageal cancer other than age. Clinical examination was unremarkable apart from stridor. Laboratory investigations, including arterial blood gas on room air, were unremarkable. Radiological examination revealed a 4.5×3.5×3.6 cm mass involving the posterior trachea and invading the tracheal orifice. Oesophagogastroduodenoscopy and rigid bronchoscopy confirmed an extensive tumour arising from the lower oesophagus and invading the trachea, causing 90% airway obstruction for a 6 mm length ending 1.5 cm above the carina. Biopsy revealed a poorly differentiated carcinoma with foci of squamous cell carcinoma. Unfortunately, the patient passed away 2 months after palliative tracheal stent placement.

Indications and complications of rigid bronchoscopy

INTRODUCTION

Rigid bronchoscopy is an invaluable tool for the management of airway disorders and an essential skill for an interventional pulmonologist. Since its introduction in the late 19th century, it has remained an important technique for the management of central airway obstruction, foreign body aspiration and massive hemoptysis. Areas covered: This article will review the history, indications, contraindication, technique and complications of rigid bronchoscopy. We will also briefly discuss the methods of anesthesia and ventilation and finally our perspective on the future of rigid bronchoscopy. Expert commentary: Although the rise of flexible bronchoscopy in the 1960s led to a decline in the use of rigid bronchoscopy, the last two decades have witnessed resurgence in its popularity. We anticipate that it will remain an important tool used by interventional pulmonologists for decades to come. We suggest that interventional pulmonologists must have training and develop expertise in this technique.

A Randomized Trial of Respiratory Status during Airway Stenting under General Anesthesia Spontaneous Respiration vs. Controlled Ventilation with Muscle Relaxants

Airway stenting is a procedure in which a stent is inserted into a stenotic site in the airway. However, the optimal ventilation for airway stenting remains controversial. We have planned a randomized, unblinded controlled study to compare intraoperative respiratory status by dividing patients, who underwent airway stenting, into spontaneous respiration (SP) and controlled ventilation with muscle relaxants (MR) groups. This study started in April 2016. The subjects, patients aged ≥20 years with airway stenosis caused by malignant neoplasms for which airway stenting was scheduled, are randomly allocated to SP and MR groups. Anesthesia management is performed in accordance with the anesthetic methods established in each group to compare parameters of the intraoperative respiratory status. The primary endpoint is the incidence of intraoperative oxygen desaturation events (SpO₂ <95). Secondary endpoints are the mean intraoperative P/F ratio, pH, PaCO₂, adverse events, and proportion of protocol treatment achievement. Currently, there is no evidence of anesthetic methods affecting airway stenting. Some studies have claimed that muscle relaxants worsen airway stenosis, while others have reported stable anesthetic management of controlled ventilation with muscle relaxants in airway stenting. This study may aid in clarifying anesthetic methods for airway stenting.

Anesthesia for interventional pulmonology procedures: a review of advanced diagnostic and therapeutic bronchoscopy

PURPOSE

Interventional pulmonology is a growing subspecialty of pulmonary medicine with flexible and rigid bronchoscopies increasingly used by interventional pulmonologists for advanced diagnostic and therapeutic purposes. This review discusses different technical aspects of anesthesia for interventional pulmonary procedures with an emphasis placed on pharmacologic combinations, airway management, ventilation techniques, and common complications.

SOURCE

Relevant medical literature was identified by searching the PubMed and Google Scholar databases for publications on different anesthesia topics applicable to interventional pulmonary procedures. Cited literature included case reports, original research articles, review articles, meta-analyses, guidelines, and official society statements.

PRINCIPAL FINDINGS

Interventional pulmonology is a rapidly growing area of medicine. Anesthesiologists need to be familiar with different considerations required for every procedure, particularly as airway access is a shared responsibility with pulmonologists. Depending on the individual case characteristics, a different selection of airway method, ventilation mode, and pharmacologic combination may be required. Most commonly, airways are managed with supraglottic devices or endotracheal tubes. Nevertheless, patients with central airway obstruction or tracheal stenosis may require rigid bronchoscopy and jet ventilation. Although anesthetic approaches may vary depending on factors such as the length, complexity, and acuity of the procedure, the majority of patients are anesthetized using a total intravenous anesthetic technique.

CONCLUSIONS

It is fundamental for the anesthesia provider to be updated on interventional pulmonology procedures in this rapidly growing area of medicine.

Perioperative nursing of tracheal silicon stent implantation in infants: report on four cases

AIMS

To report experience of perioperative nursing of tracheal silicon stent implantation in infants.

METHODS

Retrospective analysis on the cases of tracheal silicon stent implantation in infants in our hospital.

RESULTS AND CONCLUSIONS

Since middle of 2014, totally four tracheal silicon stent implantation were performed in our center. Of them, one case was recurrent tracheoesophageal fistula and the other three cases were traheomalacia. Parent's psychological support, infants' nutrition support and airway care were key responsibility for a nurse before implantation. During the procedure of stent implantation, it was responsible for a nurse to closely monitor the infants and to support operator. After the implantation, airway care and prevention of intra-airway bacterial colonization were important to avoid complications.

Respiratory support with venovenous extracorporeal membrane oxygenation during stent placement for the palliation of critical airway obstruction: case series analysis

BACKGROUND

Venovenous extracorporeal membrane oxygenation (VV ECMO) is used to support gas transfer of patients suffering from respiratory failure during various procedures. The purpose of this study was to evaluate the technical feasibility and safety of fluoroscopic stent placement under respiratory support with VV ECMO in patients with critical airway obstructions.

METHODS

We reviewed the records of 17 patients (14 male and 3 female; mean age: 63 years; range, 30-82 years) who underwent self-expandable metallic stent (SEMS) placement under VV ECMO respiratory support for critical airway obstruction caused by malignant (n=16) or benign (n=1) etiology.

RESULTS

Fluoroscopic placement of SEMS was successful in all patients (100%) with no procedure-related complications. During a mean follow-up of 83 days (range, 10-367 days), 15 (88.2%) of 17 patients showed improvement of Hugh-Jones grades (from 4.7±0.4 to 3.1±0.9, P<0.001). Removal of the endotracheal tube was possible in 11 (84.6%) of 13 patients. Weaning off ECMO was successful in all patients. The ECMO-related and stent-related complication rates were 11.7% (n=2) and 29.4% (n=5), respectively, all successfully managed by additional interventions. Indications for VV ECMO included failure of mechanical ventilation in 13 (76.5%) patients, and orthopnea in 4 (23.5%) patients.

CONCLUSIONS

Fluoroscopic stent placement under VV ECMO respiratory support can be successfully performed in patients with critical airway obstruction, especially in cases of respiratory distress despite ventilation support and an inability to lie in a supine position. However, further studies will be needed to validate the standardized methods and specific indications.

Indications of airway stenting for severe central airway obstruction due to advanced cancer

BACKGROUND

Management of severe central airway obstruction due to advanced cancer is a medical and technical challenge. The impact of airway stenting on the clinical outcome of such patients is unclear.

METHOD

This single-center, retrospective study evaluated 21 patients who underwent airway stenting for advanced cancer. We examined predictors of the post-stenting mortality, including age, serum albumin, tracheal diameter, smoking, opioid use, respiratory failure, and performance status (PS). We also compared survival according to the PS.

RESULTS

The mean survival period after stenting was 85.2 days. On univariate analysis, age, albumin, PS before airway stenting, respiratory failure, admission route, and PS grade were the candidates as possible predictors of prognosis after the procedure. On multivariate analysis, PS before airway stenting was identified as possible predictor of prognosis after stenting (HR 1.6180, 95% CI 0.969 to 2.7015, p = 0.066). The mean survival period after stenting was significantly longer in the good PS group, compared to the poor PS group (147.8 days vs. 38.2 days,p = 0.0346).

CONCLUSION

Airway stenting for advanced cancer may be more effective for patients in good general condition than in those with poor performance status.

Practical anesthetic considerations in patients undergoing tracheobronchial surgeries: a clinical review of current literature

Tracheobronchial surgeries require close cooperation and extensive communication between the anesthesia providers and the surgeons. Anesthetic management of tracheal and bronchial pathologies differ basically from regular upper airways management, due access to the patients airway is limited, mostly even practically impossible for the anesthesia providers. As a consequence, the surgeon overtakes responsibility for the airway access from the anesthesia provider in the variety of the cases. Preoperative recognition of a difficult airway, detailed planning and being aware of plan B and plan C are the elementary keys to success. Providers have to be aware, that preoperative airway assessment does not always correlate with the ease of oxygenation and ventilation. Therefore, various methods have been described in the literature and several authors have adopted unique ways to manage the airways in a successful manner. With the advancement of surgical techniques over the years, anesthetic management has also evolved tremendously to match the needs. The commonly encountered conditions requiring surgical interventions include post-intubation stenosis and foreign body aspiration. In this review we will discuss the most common pathologies of tracheobronchial lesions and specific anesthetic management considerations related to them.

Obstruction of the right stem bronchus due to ovarian local metastasis: a 5-year follow-up

Currently interventional bronchoscopy is used for debulking, desobstruction and airway patency stabilization. The interventional techniques are being used for both benign and malignant cases. There are two types of stents that are currently being used, silicon and self-expandable metallic. The method of application and stent remains for the treating physician to choose. In the current case we will present a case of metastatic disease from ovarian cancer in the airway lumen and a long term follow-up.

Placement of self-expandable bifurcated metallic stents without use of fluoroscopic and guidewire guidance to palliate central airway lesions

Background

Self-expandable metallic stents (SEMS) can be used to treat malignant obstructions and fistulas of the central airways. SEMS can be placed using different methods. Recently, a rigid bronchoscope has been used for stent placement without the need for fluoroscopy. We retrospectively evaluated patients for whom SEMS were placed using a rigid bronchoscope, without employing guidewires or fluoroscopy. We describe the intra- and post-procedural complications of the method.

Methods

Data collected between January 2014 and July 2015 were retrospectively evaluated by reference to hospital records.

Results

The mean patient age was 58.14 ± 8.48 years (44–72 years) and 13 out of the 14 patients were male. Twelve had lung cancer, one a thyroid papillary carcinoma with a bronchomediastinal fistula, and one an esophageal carcinoma with a tracheoesophageal fistula. Covered metallic Y-shaped stents were placed in all patients. Before placement, argon plasma coagulation was performed on two patients, diode laser treatment on four, and de-obstruction on nine. No procedure-related mortality was noted. Only two patients required follow-up in the intensive care unit; they were moved to a regular ward after two days. No patient required stent replacement or repositioning. The most common early complication was mucus plugs.

Conclusion

Endobronchial placement of covered self-expandable metallic stents was safe and readily performed in patients with airway obstructions. Neither fluoroscopic nor guidewire guidance was required. Neither patients nor staff were exposed to radiation, and costly guidewire guidance was not necessary. The procedure is cost-effective.

Transnasal tracheobronchial stenting for malignant airway narrowing under local anesthesia: Our experience of treating three cases using this technique

PURPOSE

To study the technical feasibility of tracheobronchial stenting via transnasal route under bronchoscopy and fluoroscopic guidance in severe malignant airway strictures using self-expandable nitinol stents.

MATERIALS AND METHODS

We describe three patients with malignant airway strictures, treated entirely via transnasal route under local anesthesia using bronchoscopic and fluoroscopic guidance. Nasal route allowed convenient access to the airway for the bronchoscope across the stricture and a guidewire was introduced through its working channel. The 18F tracheal stent and the 6F bronchial stent assembly could be easily introduced and deployed under bronchoscopic (reintroduced through the other nostril) and fluoroscopic guidance.

RESULTS

We achieved technical success in all the three patients with immediate relief of dyspnea.

CONCLUSION

Transnasal airway stenting with self-expandable nitinol stent using bronchoscopic and fluoroscopic guidance under local anesthesia is a safe and effective method with minimal patient discomfort.

Influence of Tracheal Obstruction on the Efficacy of Superimposed High-frequency Jet Ventilation and Single-frequency Jet Ventilation

BACKGROUND

Both superimposed high-frequency jet ventilation (SHFJV) and single-frequency (high-frequency) jet ventilation (HFJV) have been used with success for airway surgery, but SHFJV has been found to provide higher lung volumes and better gas exchange than HFJV in unobstructed airways. The authors systematically compared the ventilation efficacy of SHFJV and HFJV at different ventilation frequencies in a model of tracheal obstruction and describe the frequency and obstruction dependence of SHFJV efficacy.

METHODS

Ten anesthetized animals (weight 25 to 31.5 kg) were alternately ventilated with SHFJV and HFJV at a set of different fHF from 50 to 600 min. Obstruction was created by insertion of interchangeable stents with ID 2 to 8 mm into the trachea. Chest wall volume was measured using optoelectronic plethysmography, airway pressures were recorded, and blood gases were analyzed repeatedly.

RESULTS

SHFJV provided greater than 1.6 times higher end-expiratory chest wall volume than HFJV, and tidal volume (VT) was always greater than 200 ml with SHFJV. Increase of fHF from 50 to 600 min during HFJV resulted in a more than 30-fold VT decrease from 112 ml (97 to 130 ml) to negligible values and resulted in severe hypoxia and hypercapnia. During SHFJV, stent ID reduction from 8 to 2 mm increased end-expiratory chest wall volume by up to 3 times from approximately 100 to 300 ml and decreased VT by up to 4.2 times from approximately 470 to 110 ml. Oxygenation and ventilation were acceptable for 4 mm ID or more, but hypercapnia occurred with the 2 mm stent.

CONCLUSION

In this in vivo porcine model of variable severe tracheal stenosis, SHFJV effectively increased lung volumes and maintained gas exchange and may be advantageous in severe airway obstruction.

Anaesthesia for bronchoscopy

Bronchoscopy as an investigation or therapeutic procedure demands anaesthesiologist to act accordingly. The present review will take the reader from rigid to fibreoptic flexible bronchoscopy. These procedures are now done as day care procedures in the operation theatre or in critical care units. Advantages and limitations of both rigid and flexible bronchoscopy are analysed. Recently, conscious sedation has come up as the commonly used anaesthetic technique for simple bronchoscopic procedures. However, general anaesthesia still remains a standard technique for more complex procedures. New advances in the field of anaesthesiology such as use of short acting opioids, use of newer drugs such as dexmedetomidine, supraglottic airways and mechanical jet ventilators have facilitated and eased the conduct of the procedure.

Critical airway obstruction: challenges in airway management and ventilation during therapeutic bronchoscopy

BACKGROUND

Endobronchial interventions are used to alleviate symptoms of airway stenosis. The ventilatory management may be challenging during these procedures, and may influence the choice of airway device. We report our experiences from 902 procedures.

METHODS

Patients undergoing interventional bronchoscopy procedures were consecutively registered from 1999 to 2012. Critical airway obstruction (CAO) was defined as stridor, tracheal diameter <5 mm, stenosis of both the main bronchi, or clots/tumor fragments occluding the trachea or both main bronchi. Choice of airway, ventilation strategy, and survival are reported. Results are presented as median (interquartile range), and P≤0.05 was considered significant.

RESULTS

A total of 561 patients underwent 902 interventional bronchoscopy procedures (mechanical debulking, laser resection, balloon dilatation, and stent placement). The procedures were performed using flexible bronchoscope through an endotracheal tube (68.2%) or laryngeal mask airway (10.4%), or by rigid bronchoscopy (9.3%). All patients were primarily ventilated by volume-controlled ventilation. CAO was classified in 60 procedures, with more frequent use of laryngeal mask airway (21.7%), and change of airway device in 20/60 procedures. The survival for patients with malignant disease with or without CAO was 100 and 182 days, respectively, with 90 days survival probability of 0.65 and 0.51 (P=0.14).

CONCLUSIONS

Bronchoscopic treatment in patients with CAO may require a change of ventilatory and airway strategy during the procedure. Despite various challenges in the management of patients with CAO, the short-term survival in these patients is comparable to that in patients without CAO.

Endotracheal Tube Management and Obstructed Airway

Thoracic surgery encompasses a wide array of surgical techniques, most of which require lung isolation for surgical exposure in the pleural cavity; this, in turn, demands an extensive knowledge of respiratory mechanics and modalities of airway control. Likewise, effective treatment of an acute central airway obstruction calls for a systematic approach using clear communication between teams and a comprehensive knowledge of available therapeutic modalities by the surgeon.

Left mainstem bronchial laceration with perforation to right pleural cavity as complication after dynamic stent insertion

The development of science at the end of the 20^th century introduced new surgical miniinvasive techniques. Endoscopic insertion of an internal stent is an alternative to other, older techniques in the treatment of tracheobronchial stenosis. Complications are serious and require immediate intervention. We report a case of a 53-year-old patient with left mainstem bronchus perforation during insertion of a dynamic stent. The clinical presentation was characterised by right tension pneumothorax. The dynamic stent in the right pleural cavity on computed tomography scan was observed. Right postero-lateral thoracotomy, stent evacuation and tracheal sutures were performed. Tracheal granulation was treated with argon plasma coagulation. Early diagnosis and treatment offered good current effects.

Anaesthesia for tracheobronchial stent insertion using an laryngeal mask airway and high-frequency jet ventilation

An approach which promotes a rapid return to spontaneous respiration after tracheobronchial stent (TBS) insertion is considered the optimal one and is a belief shared by anaesthetists, respiratory physicians, and surgeons alike (Calvey and William (2008)). The value of the laryngeal mask airway (LMA), followed by use of the Monsoon 111 Acutronic jet ventilator pressure limiting system of ventilation, for the deployment of stents in the three individual cases that of tracheoesophageal fistula, a bronchoesophageal fistula, and tracheal compression from an invading oesophageal malignant tumour are reported. The roles of target controlled anaesthesia, high-frequency jet ventilation (HFJV), and the laryngeal mask airway in optimising the surgical field and reducing the risk of bronchospasm at emergence are advantages of this technique.

Airway fire injury during rigid bronchoscopy in a patient with a silicon stent -A case report-

Therapeutic bronchoscopy is widely employed as an effective first-line treatment for patients with central airway obstructions. Airway fires during rigid bronchoscopy are rare, but can have potentially devastating consequences. Pulmonologist and anesthesiologist undertaking this type of procedure should be aware of this serious problem and be familiar with measures to avoid this possibly fatal complication. We report the case of a 24-year-old patient with a silicone stent who experienced an electrocautery-induced airway fire during rigid bronchoscopy.

Anesthetic considerations of central airway obstruction

Central airway obstruction (CAO) is a serious presentation of lung cancer and associated chest diseases. It presents a real challenge to the anesthesiologist because usually the patient admitted to the hospital as an emergency case with high grade dyspnea scheduled to undergo rigid bronchoscopy for diagnostic and possible therapeutic interventions. In this case report, we described the anesthetic management of a patient who was admitted to our hospital with CAO.

Rigid bronchoscopy for malignant central airway obstruction from small cell lung cancer complicated by SVC syndrome

Central airway obstruction (CAO) and superior vena cava (SVC) syndrome are potentially life-threatening complications in locally advanced lung cancer. Therapeutic rigid bronchoscopy has become an critical component in the treatment of the lung cancer patients with CAO who are not surgical candidates. However, the technique may pose significant risks in patients with coexisting SVC syndrome, especially, and even more so perhaps in patients over the age of eighty. In this case report, we address the potential risks and known benefits of therapeutic bronchoscopic intervention in an 85-year-old man with small cell lung cancer who presented with acute dyspnea secondary to advanced SVC syndrome and CAO involving the lower trachea and right main bronchus. Emergent therapeutic rigid bronchoscopy resulted in a marked improvement, in dyspnea, atelectasis, and postobstructive pneumonia, allowing rapid administration of systemic chemotherapy.

Anesthesia for the patient with tracheal stenosis

Tracheal stenosis may occur secondary to trauma, tumors, infection, inflammatory diseases, or iatrogenic causes. Understanding these lesions requires a basic understanding of the physics of airflow. All of these patients must be carefully evaluated and require a series of tests, including pulmonary function tests and radiographic studies. Treatment of tracheal lesions is a multidisciplinary issue and requires the close participation of interventional pulmonologists, anesthesiologists, and surgeons.

[Tracheal stenting in patients treated due to carcinoma of the larynx]

INTRODUCTION

Stenosis of the trachea and main bronchia can occur in patients with lung, larynx, thyroid gland, esophagus, in metastatic tumors, can be also caused by trauma and foreign bodies. Treatment in this condition can be difficult. Tracheal stenosis in patients after total removal of the larynx is relatively rare. It can be caused by recidiv tumor and inflammation processes.

AIM OF THE STUDY

Was to evaluate usefulness of stents in patient with stenosis of the trachea after total laryngectomy due to squamous cell carcinoma.

MATERIAL AND METHODS

Authors described two cases of patient after total laryngectomy. Nitinol, expandable, tracheal stents were used in both cases. Placement of the stent into the trachea was relatively simple. Patients have undergone this procedure in short general anesthesia.

RESULTS

After stenting patients exhibited dramatic improvement in their respiratory symptoms and quality of life.

CONCLUSIONS

Stents are useful in cases of tracheal stenosis and the effect is related to the reason of stenosis.

Anesthetic considerations for airway stenting in adult patients

The attributable morbidity from central airway obstruction is significant. Airway stenting provides a therapeutic option to manage these complex lesions. This article focuses on the relevant anesthetic considerations of airway stenting in adult patients.

Anesthetic considerations for patients with anterior mediastinal masses

Anterior mediastinal tumors can cause severe airway and vascular compression, and these effects are exacerbated by general anesthesia. Tumor biopsy using a local anesthetic technique is preferable. General anesthesia for a biopsy procedure or resection of an anterior mediastinal mass should be undertaken only after a thorough preoperative assessment. Treatment protocols for surgery and anesthesia vary from institution to institution, and management remains operator dependent. Some consider the maintenance of spontaneous respiration during anesthesia optimal. Others advocate airway stenting. Cardiopulmonary bypass, instituted at the outset of surgery under local anesthetic, may be used as a fall-back technique in extreme circumstances.