Management of patients with "ex vacuo" pneumothorax after thoracentesis

Pneumothorax Ex-vacuo or Trapped Lungs Appearing as Iatrogenic Hydropneumothorax: A Case Report and Review of Non-expandable Lungs (NEL)

Non-expandable lungs are usually diagnosed after a pleural intervention. It can be challenging to differentiate between an iatrogenic pneumothorax and a new diagnosis of non-expandable lungs following a pleural intervention. The correct assessment can save the patient from undergoing the insertion of an unnecessary intercostal chest drain, which often leads to catastrophe. Suspicion and early evaluation remain the keys, particularly in patients with chronic effusion. Often the diagnosis is reached through a combination of history, pleural fluid analysis, and radiological features such as the absence of a straight line in the chest X-ray, which is commonly found in a true hydropneumothorax, along with computed tomographic evidence of chronic effusion with thick pleural rind. Although not routinely performed, pleural manometry can confirm the diagnosis of trapped lungs. We present our case, where a 64-year-old woman with metastatic oesophageal cancer developed a right-sided effusion. The post-procedure chest X-ray following therapeutic aspiration of the pleural fluid gave an impression of iatrogenic hydropneumothorax, which on further careful assessment revealed a rather pneumothorax ex-vacuo along with effusion due to underlying trapped lungs. We present a review of non-expandable lungs.

Pneumothorax Ex Vacuo: A Rare Complication of PleurX Catheter Insertion

Pneumothorax ex vacuo (PEV) is a rare type of pneumothorax that occurs when air enters the pleural space in the chest cavity due to an increase in the volume of the lungs or a reduction in the volume of the surrounding lung tissue. Unlike a typical pneumothorax, which involves the collapse of the lung due to air accumulation, pneumothorax ex vacuo occurs when the lung itself cannot expand properly, often due to underlying lung disease or conditions such as pulmonary fibrosis or atelectasis. The mechanism is compensatory to the lung entrapment. PleurX catheter (Pleur-Evac; Teleflex, Wayne, PA, USA) insertion can cause pneumothorax ex vacuo in patients with cancer histories, as shown in this case. It is important to understand if pneumothorax ex vacuo needs observation or quick intervention. Pleural manometry is also an important part of diagnosis of pneumothorax ex vacuo and we discuss that in our case report.

Clinical predictors and outcomes of non-expandable lung following percutaneous catheter drainage in lung cancer patients with malignant pleural effusion

Non-expandable lung (NEL) often occurs during pleural fluid drainage in patients with malignant pleural effusion (MPE). However, data regarding the predictors and prognostic impact of NEL on primary lung cancer patients with MPE receiving pleural fluid drainage, compared to malignant pleural mesothelioma (MPM), are limited. This study was aimed to investigate the clinical characteristics of lung cancer patients with MPE developing NEL following ultrasonography (USG)-guided percutaneous catheter drainage (PCD) and compare the clinical outcomes between those with and without NEL. Clinical, laboratory, pleural fluid, and radiologic data and survival outcomes of lung cancer patients with MPE undergoing USG-guided PCD were retrospectively reviewed and compared between those with and without NEL. Among 121 primary lung cancer patients with MPE undergoing PCD, NEL occurred in 25 (21%). Higher pleural fluid lactate dehydrogenase (LDH) levels and presence of endobronchial lesions were associated with development of NEL. The median time to catheter removal was significantly extended in those with NEL compared to those without (P = .014). NEL was significantly associated with poor survival outcome in lung cancer patients with MPE undergoing PCD, along with poor Eastern Cooperative Oncology Group (ECOG) performance status (PS), the presence of distant metastasis, higher serum C-reactive protein (CRP) levels, and not receiving chemotherapy. NEL developed in one-fifth of lung cancer patients undergoing PCD for MPE and was associated with high pleural fluid LDH levels and the presence of endobronchial lesions. NEL may negatively affect overall survival in lung cancer patients with MPE receiving PCD.

A Case of Pneumothorax Ex Vacuo Associated with COVID-19

Pneumothorax is a known complication of coronavirus disease 2019 (COVID-19). The concept of pneumothorax ex vacuo has also been proposed to describe pneumothorax that occurs after malignant pleural effusion drainage. Herein, we present the case of a 67-year-old woman who had abdominal distension for 2 months. A detailed examination led to the suspicion of an ovarian tumor and revealed an accumulation of pleural effusion and ascitic fluid. Thoracentesis was performed, raising the suspicion of metastasis of high-grade serous carcinoma arising from the ovary. An ovarian biopsy was scheduled to select subsequent pharmacotherapy, and a drain was inserted preoperatively into the left thoracic cavity. Thereafter, a polymerase chain reaction analysis revealed that the patient was positive for COVID-19. Thus, the surgery was postponed. After the thoracic cavity drain was removed, pneumothorax occurred, and mediastinal and subcutaneous emphysema was observed. Thoracic cavity drains were then placed again. The patient’s condition was conservatively relieved without surgery. This patient may have developed pneumothorax ex vacuo during the course of a COVID-19 infection. Since chronic inflammation in the thoracic cavity is involved in the onset of pneumothorax ex vacuo, careful consideration is required for the thoracic cavity drainage of malignant pleural effusion and other fluid retention.

Pneumothorax ex vacuo: Three cases of an uncommon entity

Pneumothorax is a frequently encountered entity in pulmonary practice and can be primary or secondary. Traumatic and iatrogenic causes also account for a minority of cases presenting to the chest physician. The most common therapeutic intervention done is a tube thoracostomy in all but the mildest of cases. Pneumothorax ex vacuo is a distinctly uncommon entity that differs considerably from the rest of the pneumothorax cases in its pathogenesis, clinical manifestations, radiological findings, and management. Pneumothorax in this entity results from the sucking in of air into the pleural space caused by an exaggerated negative intrapleural pressure, which is most frequently secondary to acute lobar collapse. Symptoms attributable to pneumothorax per se are distinctly mild and the vital aspect of treatment is to relieve the bronchial obstruction. Tube thoracostomy fails to relieve the pneumothorax in such cases and should be avoided. We share three cases of pneumothorax ex vacuo encountered in our institution and alert clinicians of the presentation, radiology, and management of this uncommon condition.

Ultrasound-guided interventional radiology procedures in the chest

Ultrasonography is a very good tool for guiding different interventional procedures in the chest. It is the ideal technique for managing conditions involving the pleural space, and it makes it possible to carry out procedures such as thoracocentesis, biopsies, or drainage. In the lungs, only lesions in contact with the costal pleura are accessible to ultrasound-guided interventions. In this type of lung lesions, ultrasound is as effective as computed tomography to guide interventional procedures, but the rate of complications and time required for the intervention are lower for ultrasound-guided procedures.

Managing complications of pleural procedures

Pleural disease is common and often requires procedural intervention. Given this prevalence, pleural procedures are performed by a wide range of providers with varying skill level in both medical and surgical specialties. Even though the overall complication rate of pleural procedures is low, the proximity to vital organs and blood vessels can lead to serious complications which if left unrecognized can be life threatening. As a result, it is of the utmost importance for the provider to have a firm grasp of the local anatomy both conceptually when preparing for the procedure and physically, via physical exam and the use of a real time imaging modality such as ultrasound, when performing the procedure. With this in mind, anyone who wishes to safely perform pleural procedures should be able to appropriately anticipate, quickly identify, and efficiently manage any potential complication including not only those seen with many procedures such as pain, bleeding, and infection but also those specific to procedures performed in the thorax such as pneumothorax, re-expansional pulmonary edema, and regional organ injury. In this article, we will review the basic approach to most pleural procedures along with essential local anatomy most often encountered during these procedures. This will lay the foundation for the remainder of the article where we will discuss clinical manifestations and management of various pleural procedure complications.

Limited Clinical Utility of Chest Radiography in Asymptomatic Patients after Interventional Radiology-Performed Ultrasound-Guided Thoracentesis: Analysis of 3,022 Consecutive Patients

Purpose The aim of this study was to report the utility of chest radiography following interventional radiology-performed ultrasound-guided thoracentesis.

Materials and Methods A total of 3,998 patients underwent thoracentesis between 2003 and 2018 at two institutions. A total of 3,022 (75.6%) patients were older than 18 years old, underwent interventional radiology-performed ultrasound-guided thoracentesis, and had same-day post-procedure chest radiograph evaluation. Patient age (years), laterality of thoracentesis, procedural technical success, volume of fluid removed (mL), method of post-procedure chest imaging, absence or presence of pneumothorax, pneumothorax size (mm), pneumothorax management measures, and clinical outcomes were recorded. Technical success was defined as successful aspiration of pleural fluid. Post-procedure clinical outcomes included new patient-perceived dyspnea and hypoxia (oxygen saturations < 90% on room air). Costs associated with radiographs were estimated using Medicare and Medicaid fee schedules.

Results Mean age was 56.7 ± 15.5 years. Interventional radiology-performed ultrasound-guided thoracentesis was performed on the left (n = 1,531; 50.7%), right (n = 1,477; 48.9%), and bilaterally (n = 14; 0.5%) using 5-French catheters. Technical success was 100% (n = 3,022). Mean volume of 940 ± 550 mL of fluid was removed. Post-procedure imaging was performed in the form of posteroanterior (PA) (2.6%; 78/3,022), anteroposterior (AP) (17.0%; 513/3,022), PA and lateral (77.9%; 2,355/3,022), or PA, lateral, and left lateral decubitus (2.5%; 76/3,022) chest radiographs. Post-procedural pneumothorax was identified in 21 (0.69%) patients. Mean pneumothorax size, measured on chest radiograph as the longest distance from the chest wall to the lung, was 18.8 ± 10.2 mm (range: 5.0–35.0 mm). Of the 21 pneumothoraces, 7 (33.3%) were asymptomatic, resolved spontaneously, and had a mean size of 6.4 ± 2.4 mm. Fourteen pneumothoraces, of mean size 25.0 ± 5.8 mm, required management with a pleural drainage catheter (66.6%). The overall incidence of pneumothorax requiring pleural drainage catheter placement following interventional radiology-performed ultrasound-guided thoracentesis was 0.46% (14/3,022). Of the patients requiring drainage catheter placement, 12/14 (85.7%) and 13/14 (92.9%) had dyspnea and hypoxia, respectively. Potential costs to Medicare and Medicaid, for chest radiographs, in this study, were $27,547 and $10,581, respectively.

Conclusion The incidence of clinically significant pneumothorax requiring catheter drainage following interventional radiology-operated ultrasound-guided thoracentesis is exceedingly low (0.46%), and routine post-procedure chest radiographs in asymptomatic patients provide little value. Reserving post-procedure chest radiographs for patients with post-procedure dyspnea or hypoxia will result in more efficient resource utilization and health care cost savings.

Avoid the Trap: Nonexpanding Lung

Nonexpanding lung is a mechanical complication in which part of the lung is unable to expand to the chest wall, preventing apposition of the visceral and parietal pleura. This can result from various visceral pleural disease processes, including malignant pleural effusion and empyema. Nonexpanding lung can be referred to as trapped lung or lung entrapment, both with distinct clinical features and management strategies. Early evaluation of pleural effusions is important to address underlying causes of pleural inflammation and to prevent the progression from lung entrapment to trapped lung. Some patients with trapped lung will not experience symptomatic relief with pleural fluid removal. Therefore, misrecognition of trapped lung can result in patients undergoing unnecessary procedures with significant cost and morbidity. We reviewed the current understanding of nonexpanding lung, which included causes, common presentations, preventative strategies, and recommendations for clinical care.

Complications of thoracentesis: incidence, risk factors, and strategies for prevention

PURPOSE OF REVIEW

Although thoracentesis is generally considered safe, procedural complications are associated with increased morbidity, mortality, and healthcare costs. In this article, we review the risk factors and prevention of the most common complications of thoracentesis including pneumothorax, bleeding (chest wall hematoma and hemothorax), and re-expansion pulmonary edema.

RECENT FINDINGS

Recent data support the importance of operator expertise and the use of ultrasound in reducing the risk of iatrogenic pneumothorax. Although coagulopathy or thrombocytopenia and the use of anticoagulant or antiplatelet medications have traditionally been viewed as contraindications to thoracentesis, new evidence suggests that patients may be able to safely undergo thoracentesis without treating their bleeding risk. Re-expansion pulmonary edema, a rare complication of thoracentesis, is felt to result in part from the generation of excessively negative pleural pressure. When and how to monitor changes in pleural pressure during thoracentesis remains a focus of ongoing study.

SUMMARY

Major complications of thoracentesis are uncommon. Clinician awareness of risk factors for procedural complications and familiarity with strategies that improve outcomes are essential components for safely performing thoracentesis.

Demystifying the persistent pneumothorax: role of imaging

Evaluation for pneumothorax is an important indication for obtaining chest radiographs in patients who have had trauma, recent cardiothoracic surgery or are on ventilator support. By definition, a persistent pneumothorax constitutes ongoing bubbling of air from an in situ chest drain, 48 h after its insertion. Persistent pneumothorax remains a diagnostic dilemma and identification of potentially treatable aetiologies is important. These may be chest tube related (kinks or malposition), lung parenchymal disease, bronchopleural fistula, or rarely, oesophageal-pleural fistula. Although radiographs remain the mainstay for diagnosis and follow up of pneumothorax, computed tomography (CT) is increasingly being used for problem solving. Aetiology of persistent air leak determines the optimal treatment. For some, a simple repositioning of the chest tube/drain may suffice; others may require surgery. In this pictorial review, we will briefly describe the physiology of pneumothorax, discuss imaging features of identifiable causes for persistent pneumothorax and provide a brief overview of treatment options. Specific aetiology of a persistent air leak may often not be immediately discernible, and will need to be carefully sought. Accurate interpretation of imaging studies can expedite diagnosis and facilitate prompt treatment.

Key points

• Persistent pneumothorax is defined as a leak persisting for more than 2 days.

• Radiographs can identify chest-tube-related causes of pneumothorax.

• CT is the most useful test to identify other causes.

• Penetrating thoracic injury can cause fistulous communication resulting in a persistent pneumothorax.

• Discontinuity of visceral pleura identified by CT may indicate a bronchopleural fistula.

Management of respiratory emergencies in small animals

Management of respiratory distress involves careful consideration of the history, physical examination, and diagnostic testing. Supplemental oxygen is useful. Urgent procedures, such as intubation, thoracococentesis, or tracheostomy, may be required. The prognosis is dependent on the underlying disease, but is often favorable. This article reviews the approach, differential diagnoses, and the approach to management for dogs and cats with respiratory distress.

Ultrasound-guided pleural puncture in supine or recumbent lateral position - feasibility study

Background

The aim of this study is to evaluate feasibility, safety and efficacy of accessing the pleural space with the patient supine or in lateral recumbent position, under constant ultrasonic guidance along the costophrenic sinus.

Methods

All patients with pleural effusion, referred to thoracentesis or pleural drainage from February 2010 to January 2011 in two institutions, were drained either supine or in lateral recumbent position through an echomonitored cannulation of the costophrenic sinus. The technique is described in detail and an analysis of safety and feasibility is carried out.

Results

One hundred and one thoracenteses were performed on 76 patients and 30 pigtail catheters were inserted in 30 patients (for a total of 131 pleural procedures in 106 patients enrolled). The feasibility of the procedures was 100% and in every case it was possible to follow real time needle tip passage in the pleural space.

Ninety eight thoracenteses (97%) and all catheter drainages were successfully completed. Four thoracenteses were stopped because of the appearance of complications while no pigtail drainage procedure was stopped. After 24 hour follow up, one chest pain syndrome (1.3% of completed thoracenteses) and two pneumothoraces (1.4%) occurred. The mean acquisition time of pleural space was 76 ± 9 seconds for thoracentesis and 185 ± 46 seconds for drainage insertion (p < 0.05).

Conclusions

This study highlights the safety and efficacy of this technique of real time echo-monitored pleural space puncture, that offers a more comfortable patient position, an easier approach for the operator, a very low rate of complications with short acquisition time of pleural space.

Pneumothorax ex-vacuo or "trapped lung" in the setting of hepatic hydrothorax

Background

Hepatic hydrothorax is a major pulmonary complication of liver disease occurring in up to 5-10% of patients with cirrhosis.

Case presentation

We report four observations of the development of pneumothorax ex-vacuo or trapped lung in the setting of hepatic hydrothorax. The diagnosis of trapped lung was made based on the presence of a hydropneumothorax after evacuation of a longstanding hepatic hydrothorax with failure of the lung to re-expand after chest tube placement in three of the four cases. Two patients underwent surgical decortication with one subsequent death from post-operative bleeding. The other two patients remarkably had spontaneous improvement of their “trapped lung” without surgical intervention.

Conclusions

While pneumothorax ex-vacuo is a known phenomenon in malignant effusions, to our knowledge, it has never been described in association with hepatic hydrothoraces. The pathophysiology of this phenomenon remains unclear but could be related to chronic inflammation with development of a fibrous layer along the visceral pleura.

Tension Pneumothorax After Placement of a Tunneled Pleural Drainage Catheter in a Patient with Recurrent Malignant Pleural Effusions

A case of tension pneumothorax developed after placement of a tunneled pleural catheter for treatment of malignant pleural effusion in a patient with advanced lung cancer. The catheter placement was carried out by an experienced operator under direct ultrasound guidance, and the patient showed immediate symptomatic improvement with acute decompensation occurring several hours later. Possible mechanisms for this serious complication of tunneled pleural catheter placement are described, and potential strategies to avoid or prevent it in future are discussed.