Characteristics of Trapped Lung

Ultrasound in the Diagnosis of Non-Expandable Lung: A Prospective Observational Study of M-Mode, B-Mode, and 2D-Shear Wave Elastography

BACKGROUND

Non-expandable lung (NEL) has severe implications for patient symptoms and impaired lung function, as well as crucial implications for the management of malignant pleural effusion (MPE). Indwelling pleural catheters have shown good symptom relief for patients with NEL; hence, identifying patients early in their disease is vital. With the inability of the lung to achieve pleural apposition following thoracentesis and the formation of a hydropneumothorax, traditionally, chest X-ray and clinical symptoms have been used to make the diagnosis following thoracentesis. It is our aim to investigate whether ultrasound measurement of lung movement during respiration can predict NEL before thoracentesis, thereby aiding clinicians in their planning for the optimal treatment of affected patients.

METHODS

A total of 49 patients were consecutively included in a single-centre trial performed at a pleural clinic. Patients underwent protocolled ultrasound assessment pre-thoracentesis with measurements of lung and diaphragm movement and shear wave elastography measurements of the pleura and pleural effusion at the planned site of thoracentesis.

RESULTS

M-mode measurements of lung movement provided the best diagnostic ROC-curve results, with an AUC of 0.81. Internal validity showed good results utilising the calibration belt test and Brier test.

CONCLUSION

M-mode measurement of lung movement shows promise in diagnosing NEL before thoracentesis in patients with known or suspected MPE. A validation cohort is needed to confirm the results.

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.

[Occult and Retained Haemothorax - Recommendations of the Interdisciplinary Thoracic Trauma Task Group of the German Trauma Society (DGU - Section NIS) and the German Society for Thoracic Surgery (DGT)]

The management of occult and retained haemothorax is challenging for all involved in the care of polytrauma patients in terms of diagnosis and treatment. The focus of decision making is preventing sequelae such as pleural empyema and avoiding a trapped lung. An interdisciplinary task force of the German Society for Thoracic Surgery (DGT) and the German Trauma Society (DGU) on thoracic trauma offers recommendations for post-trauma care of patients with occult and/or retained haemothorax, as based on a comprehensive literature review.

Recommendations of the Spanish Society of Thoracic Surgery for the management of malignant pleural effusion

This article summarizes the clinical guidelines for the diagnosis and treatment of malignant pleural effusion (MPE) sponsored by the Spanish Society of Thoracic Surgery (SECT). Ten clinical controversies were elaborated under the methodology of PICO (Patient, Intervention, Comparison, Outcome) questions and the quality of the evidence and grading of the strength of the recommendations was based on the GRADE system. Immunocytochemical and molecular analyses of pleural fluid may avoid further invasive diagnostic procedures. Currently, the definitive control of MPE can be achieved either by pleurodesis (talc poudrage or slurry) or the insertion of a indwelling pleural catheter (IPC). It is likely that the combination of both techniques (i.e., thoracoscopy with talc poudrage and insertion of a IPC, or instillation of talc slurry through a IPC) will have a predominant role in the future therapeutic management.

Predictors of lung entrapment in malignant pleural effusion

INTRODUCTION

Malignant pleural effusion (MPE) is a common complication in advanced stages of malignancy and is associated with poor prognosis. Non-expandable lung (NEL) often occurs and its presence influences the MPE approach. Our main objective was to assess risk factors for malignant NEL.

METHODS

Patients diagnosed with pathologically confirmed MPE between January 2012 and December 2018 in our institution were retrospectively analyzed. Demographic and clinical data of patients were reviewed and compared according to the presence or absence of NEL. A univariate and multivariate binary logistic regression analysis were used to determine predictors of the development of NEL.

RESULTS

Of 365 patients included, 68 (18.6%) had NEL. After multivariate analysis, we found that loculated MPE (OR 8.63, 95%CI 4.30-17.33, p<0.001), complete hemithorax opacification (OR 2.81, 95%CI 1.17-6.76, p<0.021), lung cancer (OR 2.09, 95%CI 1.01-4.31, p=0.047) and higher effusion-serum LDH ratio (OR 1.09, 95%CI 1.00-1.17, p=0.039) were independent predictors of malignant NEL. There were no significant differences compared with expandable lung group regarding time from primary malignancy diagnosis to MPE diagnosis (3.0, IQR 0.0-75.8 vs 2.0, IQR 0.0-75.5 weeks, p=0.942) or MPE symptoms onset to MPE diagnosis (4.0, IQR 1.0-9.0 vs 3.0, IQR 1.0-9.0 weeks, p=0.497). Patients with NEL had a higher number of therapeutic pleural drainages (3.0, IQR 2.0-6.0 vs 2.0, IQR 1.0-3.0; p<0.001) and longer hospital stay (32.5, IQR 15.5-46.3 vs 21.0, IQR 11.0-36.0, p=0.007), measured in hospitalization days until the end of life, than patients with expandable lung. The rate of recurrence of pleural effusion was not significantly different between groups (p=0.291). Overall survival (OS) was 3.0 (95%CI, 2.3-3.7) months, regardless of lung expandability (p=0.923).

CONCLUSION

Loculated MPE, complete hemithorax opacification, lung cancer and a higher effusion-serum LDH ratio were found to be independent predictors for NEL. These patients underwent thoracocenteses more frequently and had longer hospitalization days, although without significant impact in the OS.

Postoperative Trapped Lung After Orthotopic Liver Transplantation is a Predictor of Increased Mortality

Pleural effusions are a common complication of orthotopic liver transplantation (OLT), and chronic post-OLT pleural effusions have been associated with worse outcomes. Furthermore, “trapped lung” (TL), defined as a restrictive fibrous visceral pleural peel preventing lung re-expansion, may have prognostic significance. We performed a retrospective analysis of adult OLT recipients over a 9-year period at UCLA Medical Center. Post-OLT patients with persistent pleural effusions, defined by the presence of pleural fluid requiring drainage one to 12 months after OLT, were included for analysis. Outcomes for patients with and without TL were compared using univariate and multivariate analysis. Of the 1722 patients who underwent OLT, 117 (7%) patients met our criteria for persistent postoperative pleural effusion, and the incidence of TL was 21.4% (25/117). Compared to patients without TL, those with TL required more surgical pleural procedures (OR 59.8, 95%CI 19.7–181.4, p < 0.001), spent more days in the hospital (IRR 1.56, 95%CI 1.09–2.23, p = 0.015), and had a higher risk of mortality (HR 2.47, 95%CI 1.59–3.82, p < 0.001) following transplant. In sum, we found that post-OLT TL was associated with higher morbidity, mortality, and healthcare utilization. Future prospective investigation is warranted to further clarify the risk factors for developing postoperative pleural effusions and TL.

Malignant Pleural Effusions

Malignant pleural effusions have a significant burden on patients and the health care system. Diagnosis is typically via thoracentesis, although other times more invasive procedures are required. Management centers around relief of dyspnea and patient quality of life and can be done via serial thoracentesis, indwelling pleural catheter, or pleurodesis. This article focuses on the diagnosis and management of malignant pleural effusion.

Anatomy and Applied Physiology of the Pleural Space

The unique anatomy and physiology of the pleural space provides tight regulation of liquid within the space under normal physiologic conditions. When this balance is disrupted and pleural effusions develop, there can be significant impacts on the respiratory system. Drainage of effusions can lead to meaningful improvement in symptoms, primarily owing to improvement in the length-tension relationship of the respiratory muscles. Ultrasound examination to evaluate the movement and function of the diaphragm, as well as pleural manometry, have provided a greater understanding of the impact of pleural effusion and thoracentesis.

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.

Preoperative Trapped Lung Is Associated With Increased Mortality After Orthotopic Liver Transplantation

INTRODUCTION

Trapped lung, characterized by atelectatic lung unable to reexpand and fill the thoracic cavity due to a restricting fibrous visceral pleural peel, is occasionally seen in patients with end-stage liver disease complicated by hepatic hydrothorax. Limited data suggest that trapped lung prior to orthotopic liver transplantation may be associated with poor outcomes.

RESEARCH QUESTION

What is the clinical significance of trapped lung in patients receiving orthotopic liver transplantation?

DESIGN

We performed a retrospective analysis of patients who underwent liver transplantation over an 8-year period. Baseline clinical characteristics and postoperative outcomes of adult patients with trapped lung were analyzed and compared to the overall cohort of liver transplant recipients and controls matched 3:1 based on age, sex, Model for End-Stage Liver Disease (MELD) score, and presence of pleural effusion.

RESULTS

Of the 1193 patients who underwent liver transplantation, we identified 20 patients (1.68%) with trapped lung. The probability of 1 and 2-year survival were 75.0% and 57.1%, compared to 85.6% and 80.4% (p = 0.02) in all liver transplant recipients and 87.9% and 81.1% (p = 0.03) in matched controls respectively. Patients with trapped lung had a longer hospital length of stay compared to the total liver transplant population (geometric mean 54.9 ± 8.4 vs. 27.2 ± 0.7 days, p ≤ 0.001), when adjusted for age and MELD score.

DISCUSSION

Patients with trapped prior to orthotopic liver transplantation have increased probability of mortality as well as increased health care utilization. This is a small retrospective analysis, and further prospective investigation is warranted.

Pleural Space Elastance and Its Relation to Success Rates of Pleurodesis in Malignant Pleural Effusion

Background

Pleurodesis fails in 10%–40% of patients with recurrent malignant pleural effusions malignant pleural effusion and dyspnea. This study aimed to assess the values of pleural elastance (P_EL) after the aspiration of 500 mL of pleural fluid and their relation to the pleurodesis outcome, and to compare the pleurodesis outcome with the chemical characteristics of pleural fluid.

Methods

A prospective study was conducted in Kasr El-Aini Hospital, Cairo University, during the period from March 2019 to January 2020. The study population consisted of 40 patients with malignant pleural effusion. The measurement of P_EL after the aspiration of 500 mL of fluid was done with “P_EL 0.5” (cm H₂O/L), and the characteristics of the pleural fluid were chemically and cytologically analyzed. Pleurodesis was done and the patients were evaluated one month later. The P_EL values were compared with pleurodesis outcomes.

Results

After 4-week of follow-up, the success rate of pleurodesis was 65%. The P_EL 0.5 was significantly higher in failed pleurodesis than it was in successful pleurodesis. A cutoff point of P_EL 0.5 >14.5 cm H₂O/L was associated with pleurodesis failure with a sensitivity and specificity of 93% and 100%, respectively. The patients with failed pleurodesis had significantly lower pH levels in fluid than those in the successful group (p<0.001).

Conclusion

P_EL measurement was a significant predictor in differentiating between failed and successful pleurodesis. The increase in acidity of the malignant pleural fluid can be used as a predictor for pleurodesis failure in patients with malignant pleural effusion.

Advances in pleural effusion diagnostics

Introduction: Pleural effusion is a common clinical problem. Yet, in a significant proportion of patients (~20%), the cause of pleural effusion remains unknown. Understanding the diagnostic value of pleural fluid tests is crucial for the development of accurate diagnostic models.Areas covered: This paper provides an overview of latest advances in the diagnosis of pleural effusion based on the best evidence available.Expert opinion: For pleural fluid tests to have a good diagnostic value, it is necessary that data obtained from clinical history, physical examination, and radiological studies are correctly interpreted. Thoracentesis and pleural biopsy should always be performed under image guidance to improve its diagnostic sensitivity and prevent complications. Nucleic acid amplification tests, pleural tissue cultures, and collection of pleural fluid in blood culture bottles improve the diagnostic yield of pleural fluid cultures. Although undiagnosed pleural effusions generally have a favorable prognosis, follow-up is recommended to prevent the development of a malignant pleural effusion.

Assessment of Diaphragm Function and Pleural Pressures During Thoracentesis

BACKGROUND

This prospective observational study reports on diaphragm excursion, velocity of diaphragm contraction, and changes in pleural pressure that occur with thoracentesis.

METHODS

Twenty-eight patients with pleural effusion underwent therapeutic thoracentesis. Diaphragm excursion and velocity of diaphragm contraction were measured with M-mode ultrasonography of the affected hemidiaphragm. Pleural pressure was measured at each aliquot of 250 mL of fluid removal. Fluid removal was continued until no more fluid could be withdrawn, unless there was evidence of nonexpandable lung defined as a pleural elastance greater > 14.5 cm H₂O/L and/or ipsilateral anterior chest discomfort.

RESULTS

Twenty-three patients had expandable lung, and five patients had nonexpandable lung. Velocity of diaphragm contraction (mean ± SD) increased from 1.5 ± 0.4 cm/s to 2.8 ± 0.4 cm/s pre-thoracentesis and post-thoracentesis, respectively (CI, 0.93-1.61; P < .001) in subjects with expandable lung. Velocity of diaphragm contraction (mean ± SD) increased from 2.0 ± 0.4 cm/s to 2.3 ± 0.4 cm/s pre-thoracentesis and post-thoracentesis (P = .45) in subjects with nonexpandable lung. Diaphragm excursion was significantly increased in subjects with expandable lung at the end of thoracentesis; diaphragm excursion did not increase to a significant extent in patients with nonexpandable lung.

CONCLUSIONS

The velocity of diaphragm contraction and diaphragm excursion increased in association with fluid removal with thoracentesis in patients with expandable lung, whereas it did not significantly change in patients with nonexpandable lung. This may derive from improvement in loading conditions of the diaphragm in patients with expandable lung related to its preload and length-tension characteristics.

Approach to malignant pleural effusions: Role of pleural manometry exemplified by case scenarios

Issues related to the management of pleural effusion in India are unique. With high incidence of tuberculosis and malignancy, managing patients with pleural effusion may not be the same between patients. Decisions on intercostal chest drain insertion, volume of fluid to be removed during therapeutic thoracentesis, and further diagnostic imaging and investigations are often taken with difficulty in low-resource settings. Pleural manometry can help resolve these issues and help in the management of such patients. Pleural manometry has been advocated as a valuable tool to characterize underlying lung behavior during thoracentesis and has been proposed to be useful in diagnosing unexpandable lung, predicting the success of pleurodesis, and preventing the development of excessively negative pleural pressures which in turn may lead to the development of reexpansion pulmonary edema. There is very little literature on pleural manometry from India and other developing countries. In this article, the utility of pleural manometry in managing patients with malignant pleural effusion is discussed.

Pleural cerebrospinal fluid shunting causing trapped lung: A respiratory physician's approach to management and prevention

Cerebrospinal fluid (CSF) shunting into the pleural space can cause complications such as long-standing pleural effusions and trapped lung. These complications can be difficult to manage due to the propensity of effusions to recur, and the irreversible nature of trapped lung. This report describes the case of a woman with a pleural CSF shunt who developed chronic pleural effusions and trapped lung over two years, following a 24-year period without any respiratory shunt complications. Management options for this patient included thoracentesis, lung decortication, insertion of an indwelling pleural catheter, and shunt revision. Advocating for pleural shunt revision when symptomatic or increasingly large pleural effusions occur may prevent the development of trapped lung.

Pre-EDIT: protocol for a randomised feasibility trial of elastance-directed intrapleural catheter or talc pleurodesis (EDIT) in malignant pleural effusion

Introduction

Non-expansile lung (NEL) is a common cause of talc pleurodesis (TP) failure in malignant pleural effusion (MPE), but is often occult prior to drainage. Reliable detection of NEL would allow patients to be allocated between intrapleural catheter (IPC) and TP. High pleural elastance (P_EL) has been associated with NEL in observational studies. Pre-EDIT is a randomised feasibility trial of elastance-directed IPC or TP (EDIT) management using a novel, purpose-built digital pleural manometer (Rocket Medical, UK).

Methods and analysis

Consecutive patients with MPE without prior evidence of NEL or preference for IPC will be randomised 1:1 between EDIT management and standard care (an attempt at TP). The primary objective is to determine whether sufficient numbers of patients (defined as 30 within 12 months (or 15 over 6 months)) can be recruited and randomised to justify a subsequent phase III trial testing the efficacy of EDIT management. Secondary objectives include safety, technical feasibility and validation of study design elements, including the definition of P_EL using 4D pleural MRI before and after fluid aspiration. EDIT involves P_EL assessment during a large volume pleural fluid aspiration, followed by an attempt at TP or placement of an IPC within 24 hours. Patients will be allocated to IPC if the rolling average P_EL sustained over at least 250 mL fluid aspirated (P_EL250) is ≥ 14.5 cm H₂O/L.

Ethics and dissemination

Pre-EDIT was approved by the West of Scotland Regional Ethics Committee on 8 March 2017 (Ref: 17/WS/0042). Results will be presented at scientific meetings and published in peer-reviewed journals.

Trial registration number

NCT03319186; Pre-results.

Thoracoscopic decortication for the management of trapped lung caused by 14-year pneumothorax: A case report

Trapped lung is defined by the lung's inability to expand and fill the thoracic cavity because of a restricting “peel” caused by benign or malignant pleural disease. However, trapped lung secondary to pneumothorax is rarely reported. We present a case of trapped lung caused by a pneumothorax that occurred some 14 years before the patient presented to our hospital with a complaint of incapacitating dyspnea. Computed tomography (CT) scans revealed trapping of the right lung with abnormal thickening of the visceral pleura. In view of the patient's history of pneumothorax, we concluded that his dyspnea was attributable mainly to the trapping of his lung by the earlier pneumothorax. We therefore scheduled thoracoscopic decortication, which was successfully completed. The patient's recovery after the operation was uneventful, and seven weeks after surgery the right lung had re‐expanded well.

What happens to the pleural space affected by malignant effusion after bedside pleurodesis?

BACKGROUND AND OBJECTIVES

Evaluate radiological characteristics of postpleurodesis pleural space of patients with recurrent malignant pleural effusion(RMPE).

METHODS

Prospective cohort study including patients with RPME treated with bedside pleurodesis. We used CT scans to calculate pleural cavity volume immediately before pleurodesis(iCT) and 30 days after(CT30). Radiological evolution was calculated by the difference between pleural volumes on CT30 and iCT(Δvolume). We categorized initial pleural volume as small(<500 mL) or large space(≥500 mL) and Δvolume as positive(>254.49 mL), unchanged(≥-268.77-≤ 254.49 mL), or negative(<-268.77 mL). Futhermore, we analyzed clinical effectiveness, pleural elastance, and adverse events.

RESULTS

A total of 87 patients were analyzed. Pleural volume varied from 35-2750 mL in iCT and from 0-2995 mL in CT30(P = 0.753). A total of 54 patients had initial small pleural space(62.06%) and 33 large(37.93%). Clinical failure occurred in 7.4% of small space group and in 24.6% of large(P = 0.051, OR4.0(CI:1.098-14.570)). In small space group, 27.77% evolved with positive, 66.66% with unchanged and 5.55% with negative Δvolume. In the large space group these numbers were respectively 21.21%, 27.27%, and 51.51%.

CONCLUSIONS

There is significant variability on pleural space volume. However, pleural volume remains unchanged in many cases. Besides that, more than half patients with initial large space coursed with relevant reduction. Finally, patients with initial small space presented a greater chance of clinical success.

Patterns of pleural pressure amplitude and respiratory rate changes during therapeutic thoracentesis

BACKGROUND

Although the impact of therapeutic thoracentesis on lung function and blood gases has been evaluated in several studies, some physiological aspects of pleural fluid withdrawal remain unknown. The aim of the study was to assess the changes in pleural pressure amplitude (Ppl_ampl) during the respiratory cycle and respiratory rate (RR) in patients undergoing pleural fluid withdrawal.

METHODS

The study included 23 patients with symptomatic pleural effusion. Baseline pleural pressure curves were registered with a digital electronic manometer. Then, the registrations were repeated after the withdrawal of consecutive portions of pleural fluid (200 ml up to 1000 ml and 100 ml above 1000 ml). In all patients the pleural pressure curves were analyzed in five points, at 0, 25%, 50%, 75% and 100% of the relative volume of pleural effusion withdrawn in particular patients.

RESULTS

There were 11 and 12 patients with right sided and left sided pleural effusion, respectively (14 M, 9F, median age 68, range 46-85 years). The most common cause of pleural effusion were malignancies (20 pts., 87%). The median total volume of withdrawn pleural fluid was 1800 (IQR 1500-2400) ml. After termination of pleural fluid withdrawal Ppl_ampl increased in 22/23 patients compared to baseline. The median Ppl_ampl increased from 3.4 (2.4-5.9) cmH₂O to 10.7 (8.1-15.6) cmH₂O (p < 0.0001). Three patterns of Ppl_ampl changes were identified. Although the patterns of RR changes were more diversified, a significant increase between RR at baseline and the last measurement point was found (p = 0.0097).

CONCLUSIONS

In conclusion, therapeutic thoracentesis is associated with significant changes in Ppl_ampl during the respiratory cycle. In the vast majority of patients Ppl_ampl increased steadily during pleural fluid withdrawal. There was also an increase in RR. The significance of these changes should be elucidated in further studies.

TRIAL REGISTRATION

ClinicalTrial.gov, registration number: NCT02192138 , registration date: July 1st, 2014.

Pleural manometry in patients with pleural diseases - the usefulness in clinical practice

Although pleural manometry is a relatively simple medical procedure it is only occasionally used to follow pleural pressure (Ppl) changes during a therapeutic thoracentesis and pneumothorax drainage. As some studies showed that pleural pressure monitoring might be associated with significant advantages, pleural manometry has been increasingly evaluated in the last decade. The major clinical applications of pleural pressure measurements include: the prevention of complications associated with large volume thoracentesis, diagnosis and differentiation between various types of an unexpandable lung and a possible prediction of the efficacy of chest tube drainage in patients with spontaneous pneumothorax. It is well known that the therapeutic thoracentesis might be complicated by cough, chest discomfort, and rarely, by a life threatening condition called reexpansion pulmonary edema (RPE). The serious adverse events of thoracentesis are related to pleural pressure drop rather than to the volume of removed pleural effusion. The use of pleural manometry during pleural fluid withdrawal enables the evaluation of the relationship between withdrawn pleural fluid volume, pleural pressure changes and procedure related complications. Pleural pressure measurement is also an important tool to study the different mechanism of pneumothorax complicating the thoracentesis. Pleural manometry is critical for measurement of pleural elastance, diagnosis of an unexpandable lung and differentiation between trapped lung and lung entrapment. This usually has significant clinical implications in terms of further management of patients with pleural effusion. The paper is a comprehensive review presenting different aspects of pleural pressure measurement in clinical practice.

Pleural manometry-historical background, rationale for use and methods of measurement

Subatmospheric pleural pressure (Ppl), which is approximately -3 to -5 cmH₂O at functional residual capacity (FRC) makes pleura a unique organ in the human body. The negative Ppl is critical for maintaining the lungs in a properly inflated state and for proper blood circulation within the thorax. Significant and sudden pleural pressure changes associated with major pleural pathologies, as well as therapeutic interventions may be associated with life-threatening complications. The pleural pressure may show two different values depending on the measurement method applied. These are called pleural liquid pressure and pleural surface pressure. It should also be realized that there are significant differences in pleural pressure distribution in pneumothorax and pleural effusion. In pneumothorax, the pressure is the same throughout the pleural space, while in pleural effusion there is a vertical gradient of approximately 1 cm H₂O/cm in the pleural pressure associated with the hydrostatic pressure of the fluid column. Currently, two main methods of pleural pressure measurement are used: simple water manometers and electronic systems. The water manometers are conceptually simple, cheap and user-friendly but they only allow the estimation of the mean values of pleural pressure. The electronic systems for pleural pressure measurement are based on pressure transducers. Their major advantages include precise measurements of instantaneous pleural pressure and the ability to display and to store a large amount of data. The paper presents principles and details of pleural pressure measurement as well as the rationale for its use.

Better With Ultrasound: Pleural Procedures in Critically Ill Patients

Procedures designed to drain fluid or air from the pleural spaces can be technically challenging in patients who are critically ill, and are associated with significant complications. Many individual ultrasound techniques have been described, each with the goal of making pleural drainage procedures safer. This article presents a systemic approach for incorporating many of these tools into procedures such as diagnostic thoracentesis, therapeutic drainage, and pleural catheter insertion. A series of illustrative figures and narrated video presentations are included to demonstrate many of the described techniques.

Diagnosis and Management of Pleural Transudates

Various clinical trials have been published on the optimal clinical management of patients with pleural exudates, particularly those caused by malignant tumors, while little information is available on the diagnosis and treatment of pleural transudates. The etiology of pleural transudates is wide and heterogeneous, and they can be caused by rare diseases, sometimes constituting a diagnostic challenge. Analysis of the pleural fluid can be a useful procedure for establishing diagnosis. Treatment should target not only the underlying disease, but also management of the pleural effusion itself. In cases refractory to medical treatment, invasive procedures will be necessary, for example therapeutic thoracentesis, pleurodesis with talc, or insertion of an indwelling pleural catheter. Little evidence is currently available and no firm recommendations have been made to establish when to perform an invasive procedure, or to determine the safest, most efficient approach in each case. This article aims to describe the spectrum of diseases that cause pleural transudate, to review the diagnostic contribution of pleural fluid analysis, and to highlight the lack of evidence on the efficacy of invasive procedures in the management and control of pleural effusion in these patients.

Case 238: Spontaneous Pneumothorax Secondary to Intrapulmonary Necrobiotic Rheumatoid Nodule

History A 54-year-old white woman with a history of rheumatoid arthritis who was taking glucocorticoids and methotrexate presented to the emergency department in December with worsening shortness of breath and chest heaviness for 1 week. She reported additional symptoms of weakness, headache, and arthralgia primarily involving her bilateral hands, wrist, ankles, and feet. She denied experiencing fevers, syncope or presyncope, focal neurologic deficits, chest pain, nausea, vomiting, unintentional weight loss, or recent trauma. Additional medical history included hypertension, asthma, degenerative disk disease, and migraine, all of which were reportedly controlled with medications. This patient had a smoking history of 80 pack-years, but she had quit smoking 2 months prior to presentation. She denied abuse of alcohol or recreational drugs and reported she was up-to-date on her immunizations, including those for pneumonia and flu. Family history was pertinent for breast cancer in her mother, sister, and maternal aunt. The patient reported normal findings at screening mammography and colonoscopy. A physical examination was remarkable for slightly asymmetric breath sounds, which appeared to be diminished on the right side. This patient had multiple joint deformities, most notably in the bilateral metacarpophalangeal joints. Initial electrocardiography findings and cardiac biomarkers were negative. Her complete blood count and basic metabolic profile were unremarkable. Posteroanterior and lateral chest radiographs were obtained in the emergency department. Subsequently, computed tomography (CT) of the chest was performed.

The management of benign non-infective pleural effusions

The evidence base concerning the management of benign pleural effusions has lagged behind that of malignant pleural effusions in which recent randomised trials are now informing current clinical practice and international guidelines.

The causes of benign pleural effusions are broad, heterogenous and patients may benefit from individualised management targeted at both treating the underlying disease process and direct management of the fluid. Pleural effusions are very common in a number of non-malignant pathologies, such as decompensated heart failure, and following coronary artery bypass grafting. Pleural fluid analysis forms an important basis of the diagnostic evaluation, and more specific assays and imaging modalities are helpful in specific subpopulations.

Options for management beyond treatment of the underlying disorder, whenever possible, include therapeutically aspirating the fluid, talc pleurodesis and insertion of an indwelling pleural catheter. Randomised trials will inform clinicians in the future as to the risks and benefits of these options providing a guide as to how best to manage patient symptoms in this challenging clinical setting.

Benign pleural effusion management is challenging and based on limited evidence. Treatment options are discussedhttp://ow.ly/10EOSN

Transudative chylothorax from cirrhosis complicated by lung entrapment

A patient with long-standing cirrhosis due to hepatitis C and hepatic hydrothorax was evaluated for increasing symptoms and presence of a large right pleural effusion. Thoracentesis revealed evidence of a chylothorax with rapid reaccumulation of pleural fluid. Repeat thoracentesis with manometry identified presence of entrapped lung which complicated treatment options. This is the first case report of a hepatic chylothorax with features of entrapped lung.

Chyliform effusion without pleural thickening in a patient with rheumatoid arthritis: A case report

Pseudochylothorax, also known as chyliform effusion rich in cholesterol crystals, is a rare entity that sometimes occurs in long-standing rheumatoid arthritis (RA) and is usually associated with thickened pleura. There have only been a few case reports in the literature on pseudochylothorax unassociated with pleural thickening and with a short duration of articular symptoms in patients with RA. We report the case of a 70-year-old male patient with a history of RA and heart failure due to severe aortic stenosis, who presented with signs and symptoms of decompensated heart failure due to a moderate right-sided pleural effusion that was consequently proved to be pseudochylothorax unassociated with pleural thickening on chest computed tomography (CT) scan. The patient's outcome was favorable after thoracocentesis was carried out and leflunomide was added to the standard heart failure treatment.

Impact of pleural manometry on the development of chest discomfort during thoracentesis: a symptom-based study

BACKGROUND

Routine manometry is recommended to prevent complications during therapeutic thoracentesis, but has not definitively been shown to prevent pneumothorax or reexpansion pulmonary edema. As chest discomfort correlates with negative pleural pressures, we aimed to determine whether the use of manometry could anticipate the development of chest discomfort during therapeutic thoracentesis.

METHODS

A retrospective chart review of 214 consecutive adults who underwent outpatient therapeutic thoracentesis at our institution between January 1, 2011 and June 30, 2013 was performed. We compared preprocedural to postprocedural discomfort (using a linear analog scale from 0 to 10) in patients undergoing thoracentesis with or without manometry. We used a multivariate model to adjust for possible confounders. Changes of dyspnea scores were also analyzed.

RESULTS

Manometry was performed in 82/214 patients (38%). On univariate and multivariate analyses, neither the change in chest discomfort nor dyspnea scores was significantly different in the manometry versus the control group (P=0.12 and 0.24, respectively). Similar results were also found in the subgroup of large-volume thoracentesis (P=0.32 for discomfort, P=1.0 for dyspnea).

CONCLUSIONS

In our retrospective study, the use of manometry did not appear to anticipate the development of chest discomfort during therapeutic thoracentesis. Prospective studies are needed to confirm these findings.

The role of interventional therapy for pleural diseases

Pleural diseases encompass a vast and heterogeneous group of diseases that have traditionally received relatively little attention from researchers, resulting in empiric approaches to patient management based largely on expert opinions and anecdotal evidence. Yet, paradoxically, pleural diseases represent a considerable burden for patients, providers, and the healthcare system as a whole, with a rising incidence of malignant pleural effusions and pleural space infections, in increasingly complex patients. Fortunately, the last decade has witnessed unprecedented research efforts from the pleural community, which have resulted in substantial advances in risk-stratification, patient selection, treatment efficacy and the development of evidence-based recommendations ultimately leading to improved patient care. In this review, we will present a summary of the current evidence for the management of pleural diseases with an emphasis on interventional procedures, and highlight the need for future research efforts in the field of malignant pleural effusions, pleural space infections and pneumothorax.

Encapsulating peritoneal sclerosis--correlation of radiological findings at CT with underlying pathogenesis

Encapsulating peritoneal sclerosis (EPS) is a rare entity most commonly associated with peritoneal dialysis (PD). Several imaging features at computed tomography (CT) are common to many diseases; however, appreciation of the features unique to this condition interpreted with the appropriate clinical findings is crucial to diagnosis.

The evaluation and clinical application of pleural physiology

Pleural disease is commonly encountered by the chest physician. Evaluation of pleural disease typically begins with thoracentesis and pleural fluid analysis. With improvements in minimally invasive procedures, imaging, and the use of pleural manometry, a more complete understanding of lung, pleural, and chest wall physiology is possible. The improved knowledge of pleural physiology can help the clinician in clinical decision making, as well as the diagnosis and treatment of pleural disease. This article reviews pleural physiology and summarizes the relevant data supporting the use of ultrasound and manometry in the evaluation and treatment of pleural disease.

IgG4-related systemic disease presenting with lung entrapment and constrictive pericarditis

We describe a 29-year-old woman who presented with chronic pleuropericarditis complicated by lung entrapment and constrictive pericarditis. Pleural biopsy performed during the decortication procedure revealed fibrinous pleuritis with lymphoplasmacytic inflammation including IgG4-positive plasma cells. The patient responded favorably to corticosteroid therapy with resolution of pleural effusion and constrictive physiology. To our knowledge, this is the first reported case of IgG4-related systemic disease manifesting as lung entrapment and constrictive pericarditis.

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.

Haemothorax and thoracic spine fractures in the elderly

Both osteoporotic fractures and pleural effusions are frequently observed in medicine. However, rarely does one associate a hemorrhagic pleural effusion with a thoracic spinal fracture when the patient has not sustained massive trauma. In this paper, we discuss two cases where seemingly insignificant low-energy trauma precipitated massive haemothoraces in elderly patients with underlying osteoporosis, ultimately resulting in their immediate causes of death. This paper serves to remind health care professionals of the importance of using caution when moving elderly patients as well as to consider thoracic spinal fracture as a potential explanation for a hemorrhagic pleural effusion of undetermined etiology.

Getting the most from pleural fluid analysis

Virtually, every pulmonary disease and most non-pulmonary diseases may be associated with a pleural effusion. The presence of a pleural effusion allows the clinician to 'diagnose' or narrow the differential diagnosis and aetiology of the fluid collection. However, pleural fluid analysis (PFA) in isolation rarely provides a definitive diagnosis. This review discusses the rationale for evaluating patients with a pleural effusion. If the clinician obtains a detailed history, performs a comprehensive physical examination, reviews pertinent blood tests, and evaluates the chest imaging findings prior to thoracentesis, there should be a high likelihood of establishing a firm clinical diagnosis based on the appropriate PFA. This manuscript reviews the clinical presentation, chest imaging findings, duration and natural course of specific pleural effusions to help narrow the range of pre-thoracentesis diagnoses. A diagnosis of transudative effusion confirms an imbalance in hydrostatic and oncotic pressures, normal pleura and a limited differential diagnosis, which is typically apparent from the clinical presentation. Exudates are the result of infections, malignancies, inflammation, impaired lymphatic drainage or the effects of drugs, and pose a greater diagnostic challenge. The differential diagnosis for a pleural exudate can be narrowed if LDH levels exceed 1000 IU/L, the proportion of lymphocytes is ≥80%, pleural fluid pH is <7.30 or there is pleural eosinophilia of >10%.