Independent lung ventilation: Implementation strategies and review of literature

Successful Treatment of Unilateral Pulmonary Edema as Minimally Invasive Mitral Valve Surgery Complication-Case Presentation

Background/Objectives: In recent decades, the advantages of minimizing surgical trauma have led to the development of minimally invasive surgical procedures. While the benefits often outweigh the risks, several challenges are encountered that are not present in conventional surgical approaches. Unilateral pulmonary edema (UPE) after mitral interventions performed through a right-sided approach is a rare but potentially life-threatening event. Methods: We present the case of a 49-year-old patient who underwent endoscopic mitral valve repair. Immediately following ICU admission, the patient's oxygen saturation suddenly dropped, and serous discharge was exteriorized from the endotracheal tube, with a thoracic X-ray revealing right-sided unilateral pulmonary edema. Results: The therapeutical course was complex. The patient developed hemodynamic instability, leading to cardiac arrest, which required cardiopulmonary resuscitation and the initiation of peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO). The endotracheal cannula was replaced with a right-sided double-lumen cannula, and the patient was placed on two ventilators operating independently. The patient was weaned off extracorporeal membrane oxygenation (ECMO) on the fifth day and extubated on the sixth postoperative day. Conclusions: We successfully treated this patient using ECMO and independent lung ventilation. Several cases have been described in the literature, but the pathogenesis and risk factors of UPE remain unclear. Management depends on the severity of UPE, but a deeper understanding of its underlying mechanisms could provide cardiac surgeons with enhanced strategies for preventing UPE and implementing timely interventions.

Isolated Lung Ventilation With Tracheostomy Using Two Intubation Tubes for Severe Endotracheal Hemorrhage Due to Pulmonary Contusion

A 72-year-old man presented with severe pulmonary contusions and multiple traumas, including aortic injury, pelvic fracture, and renal injury. The patient required multidisciplinary treatment, including transcatheter arterial embolization, thoracic endovascular aortic repair, right lung upper lobe partial resection, and massive transfusion. During the initial treatment, the patient experienced respiratory failure due to endotracheal bleeding, and we attempted isolated lung ventilation with a 37 Fr double-lumen endotracheal intubation tube. Although drainage by suction and protection of the healthy lung was vital, the patient was unable to maintain ventilation volume because of poor drainage. Additionally, the respiratory status deteriorated. To resolve the situation, a tracheotomy was performed and two endotracheal intubation tubes (6.0 mm inner diameter, and 9.0 mm outer diameter) were inserted through a large U-shaped tracheal hole 18 hours after admission. The respiratory status of the patient gradually improved after the procedure. There were two advantages of this method of respiratory management. Firstly, each of the two endotracheal tubes had a separate cuff, allowing more reliable separation of the healthy lung from the injured lung. Secondly, bronchoscopes of sufficient diameter (4.9 mm outer diameter ) were used bilaterally, allowing sufficient drainage of viscous airway secretions mixed with hematoma and improving atelectasis. Although venovenous extracorporeal membrane oxygenation is a crucial support tool when the respiratory status deteriorates due to severe pulmonary contusions, our method of airway management may be attempted in patients with multiple traumatic injuries with coagulopathy.

Combined use of veno-venous extracorporeal membrane oxygenation and asynchronous independent lung ventilation after thoracic surgery for lung abscess

We used independent lung ventilation (ILV) during veno-venous extracorporeal membrane oxygenation (V-V ECMO) after lung abscess surgery in a patient with severe hypoxia and air leak. ILV can be effective in V-V ECMO as unilateral lung air leak.

Proof-of-concept study of compartmentalized lung ventilation using system for asymmetric flow regulation (SAFR)

Asymmetrical distribution of acute lung injury in mechanically ventilated patients can result in a heterogeneity of gas distribution between different regions, potentially worsening ventilation-perfusion matching. Furthermore, overdistension of healthier, more compliant lung regions can lead to barotrauma and limit the effect of increased PEEP on lung recruitment. We propose a System for Asymmetric Flow Regulation (SAFR) which, combined with a novel double lumen endobronchial tube (DLT) may offer individualized lung ventilation to the left and right lungs, better matching each lung's mechanics and pathophysiology. In this preclinical experimental model, the performance of SAFR on gas distribution in a two-lung simulation system was tested. Our results indicate that SAFR may be a technically feasible and potentially clinically useful although further research is warranted.

Segmental Lung Recruitment in Patients with Bilateral COVID-19 Pneumonia Complicated by Acute Respiratory Distress Syndrome: A Case Report

Bilateral COVID-19 pneumonia is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and usually leads to life-threatening acute respiratory distress syndrome (ARDS). Treatment of patients with ARDS is difficult and usually involves protective mechanical ventilation and various types of recruitment maneuvers. A segmental lung recruitment maneuver by independent lung ventilation has been described as a successful recruitment maneuver in patients with lobar pneumonia, and may, therefore, be useful for the treatment of patients with bilateral COVID-19 pneumonia complicated by ARDS in the critical phase of the disease when all other therapeutic options have been exhausted. The aim of this case series was to present a case report of four mechanically ventilated patients with severe bilateral COVID-19 pneumonia complicated by ARDS using the segmental lung recruitment maneuver. The effect of the segmental lung recruitment maneuver was assessed by the increase in PaO₂/FiO₂ ratio and the lung ultrasound (LUS) scoring system (0 points-presence of sliding lungs with A-lines or one or two isolated B-lines; 1 point-moderate loss of lung ventilation with three to five B lines; 2 points-severe loss of lung ventilation with more than five B lines (B pattern); and 3 points-lung consolidation) determined 12, 24, and 48 h after segmental lung recruitment. In three of four patients with bilateral COVID-19 pneumonia complicated by ARDS, an increase in the PaO₂/FiO₂ ratio and an improvement in the LUS scoring system were observed 48 h after segmental lung recruitment. In conclusion, the segmental lung recruitment maneuver in patients with bilateral COVID-19 complicated by ARDS is an effective method of lung recruitment and may be a useful treatment method.

Asymmetrical Lung Injury: Management and Outcome

Among mechanically ventilated patients, asymmetrical lung injury is probably extremely frequent in the intensive care unit but the lack of standardized measurements does not allow to describe any prevalence among mechanically ventilated patients. Many past studies have focused only on unilateral injury and have mostly described the effect of lateral positioning. The good lung put downward might receive more perfusion while the sick lung placed upward receive more ventilation than supine. This usually results in better oxygenation but can also promote atelectasis in the healthy lung and no consensus has emerged on the clinical indication of this posture. Recently, electrical impedance tomography (EIT) has allowed for the first time to precisely describe the distribution of ventilation in each lung and to better study asymmetrical lung injury. At low positive-end-expiratory pressure (PEEP), a very heterogeneous ventilation exists between the two lungs and the initial increase in PEEP first helps to recruit the sick lung and protect the healthier lung. However, further increasing PEEP distends the less injured lung and must be avoided. The right level can be found using EIT and transpulmonary pressure. In addition, EIT can show that in the two lungs, airway closure is present but with very different airway opening pressures (AOPs) which cannot be identified on a global assessment. This may suggest a very different PEEP level than on a global assessment. Lastly, epidemiological studies suggest that in hypoxemic patients, the number of quadrants involved has a strong prognostic value. The number of quadrants is more important than the location of the unilateral or bilateral nature of the involvement for the prognosis, and hypoxemic patients with unilateral lung injury should probably be considered as requiring lung protective ventilation as classical acute respiratory distress syndrome.

Independent Lung Ventilation-Experimental Studies on a 3D Printed Respiratory Tract Model

Independent lung ventilation (ILV) is a life-saving procedure in unilateral pulmonary pathologies. ILV is underused in clinical practice, mostly due to the technically demanding placement of a double lumen endotracheal tube (ETT). Moreover, the determination of ventilation parameters for each lung in vivo is limited. In recent years, the development of 3D printing techniques enabled the production of highly accurate physical models of anatomical structures used for in vitro research, considering the high risk of in vivo studies. The purpose of this study was to assess the influence of double-lumen ETT on the gas transport and mixing in the anatomically accurate 3D-printed model of the bronchial tree, with lung lobes of different compliances, using various ventilation modes. The bronchial tree was obtained from Respiratory Drug Delivery (RDD Online, Richmond, VA, USA), processed and printed by a dual extruder FFF 3D printer. The test system was also composed of left side double-lumen endotracheal tube, Siemens Test Lung 190 and anesthetic breathing bag (as lobes). Pressure and flow measurements were taken at the outlets of the secondary bronchus. The measured resistance increased six times in the presence of double-lumen ETT. Differences between the flow distribution to the less and more compliant lobe were more significant for the airways with double-lumen ETT. The ability to predict the actual flow distribution in model airways is necessary to conduct effective ILV in clinical conditions.

Independent Lung Ventilation in a Pediatric Patient with a Firearm Injury

Background: Chest trauma is uncommon in pediatric patients, however, it may be a cause of significant morbidity and mortality. The type and extent of the injury may lead to ventilation and perfusion problems, therefore, there may be a need for mechanical ventilation. Conclusions: "Independent lung ventilation" may be an appropriate option in selected cases in which the aim is to protect the healthy lung or ventilation cannot be obtained with known mechanical ventilation methods. Case: We presented a pediatric patient followed up in the intensive care unit because of a firearm injury, in whom left lung expansion could not be obtained despite repeated interventions, and independent lung ventilation resulted in success.

New acute respiratory management in tracheal rupture caused by chest trauma

We report a case who is a 33-year-old man admitted to our Emergency room for chest trauma caused by the factory's mechanical arm. Despite the endotracheal tube, the patient's respiratory state was poor and the oxygen saturation did not improve and the subcutaneous emphysema progressed. To improve distressed breathing, we first proposed the concept "mechanical ventilation with dual ventilator" to maintain oxygen saturation of the patient. This is, to our knowledge, the first report of using a special mechanical ventilation method in emergency surgery.

The Year in Thoracic Anesthesia: Selected Highlights from 2019

THIS special article is the 4th in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor-in-chief, Dr. Kaplan; the associate editor-in-chief, Dr. Augoustides; and the editorial board for the opportunity to expand this series, the research highlights of the year that specifically pertain to the specialty of thoracic anesthesia. The major themes selected for 2019 are outlined in this introduction, and each highlight is reviewed in detail in the main body of the article. The literature highlights in this specialty for 2019 include updates in the preoperative assessment and optimization of patients undergoing lung resection and esophagectomy, updates in one lung ventilation (OLV) and protective ventilation during OLV, a review of recent meta-analyses comparing truncal blocks with paravertebral catheters and the introduction of a new truncal block, meta-analyses comparing nonintubated video-assisted thoracoscopic surgery (VATS) with those performed using endotracheal intubation, a review of the Society of Thoracic Surgeons (STS) recent composite score rating for pulmonary resection of lung cancer, and an update of the Enhanced Recovery After Surgery (ERAS) guidelines for both lung and esophageal surgery.