Pleural effusion during weaning from mechanical ventilation: a prospective observational multicenter study

Role of interventional pulmonology in intensive care units: A scoping review

Interventional pulmonology (IP) represents a rapidly growing and developing subspecialty within pulmonary medicine. To the intensivist, given the elaborate undertakings with respect to airway, lung and pleural disease management-IP has shown an increasing presence and remain a major ally in the care of these patients. Thus, an understanding of the different roles that IP could offer to the intensivist is of prime importance in the multi-disciplinary care of the complex patients within the intensive care units, particularly in relation to lung, airway and pleural diseases. This review article will explore the different intersections of IP in critical care and discuss the applications of this discipline within the highly complex critical care environment.

Predicting Successful Weaning through Sonographic Measurement of the Rapid Shallow Breathing Index

Background: Diaphragmatic dysfunction correlates with weaning failure, highlighting the need to independently assess the diaphragm's effects on weaning. We modified the rapid shallow breathing index (RSBI), a predictor of successful weaning, by incorporating temporal variables into existing ultrasound-derived diaphragm index to create a simpler index closer to tidal volume. Methods: We conducted a prospective observational study of patients who underwent a spontaneous breathing trial in the medical intensive care unit (ICU) at Severance Hospital between October 2022 and June 2023. Diaphragmatic displacement (DD) and diaphragm inspiratory time (Ti) were measured using lung ultrasonography. The modified RSBI was defined as follows: respiratory rate (RR) divided by DD was defined as D-RSBI, and RR divided by the sum of the products of DD and Ti on both sides was defined as DTi-RSBI. Results: Among the sonographic indices, DTi-RSBI had the highest area under the receiver operating characteristic (ROC) curve of 0.774 in ROC analysis, and a correlation was found between increased DTi-RSBI and unsuccessful extubation in a multivariable logistic regression analysis (adjusted odds ratio 0.02, 95% confidence interval 0.00-0.97). Conclusions: The DTi-RSBI is beneficial in predicting successful weaning in medical ICU patients.

Establishment and validation of a predictive nomogram for severe pleural effusion in liver cancer patients after hepatectomy

This study aims to develop and validate a predictive nomogram for severe postoperative pleural effusion (SPOPE) in patients undergoing hepatectomy for liver cancer. A total of 536 liver cancer patients who underwent hepatectomy at the Department of Hepatobiliary Surgery I of the Affiliated Hospital of North Sichuan Medical College from January 1, 2018, to December 31, 2022, were enrolled in a retrospective observational study and comprised the training dataset. Lasso regression and logistic regression analyses were employed to construct a predictive nomogram. The nomogram was internally validated using Bootstrapping and externally validated with a dataset of 203 patients who underwent liver cancer resection at the Department of General Surgery III of the same hospital from January 1, 2020, to December 31, 2022. We evaluated the nomogram using the receiver operating characteristic curve, calibration curve, and decision curve analysis. Variables such as drinking history, postoperative serum albumin, postoperative total bilirubin, right hepatectomy, diaphragm incision, and intraoperative blood loss were observed to be associated with SPOPE. These factors were integrated into our nomogram. The C-index of the nomogram was 0.736 (95% CI: 0.692-0.781) in the training set and 0.916 (95% CI: 0.872-0.961) in the validation set. The nomogram was then evaluated using sensitivity, specificity, positive predictive value, negative predictive value, calibration curve, and decision curve analysis. The nomogram demonstrates good discriminative ability, calibration, and clinical utility.

Pleural effusion and thoracentesis in ICU patients: A longitudinal observational cross-sectional study

BACKGROUND

Pleural effusion is common among patients in the intensive care unit (ICU) but reported prevalence varies. Thoracentesis may improve respiratory status, however, indications for this are unclear. We aimed to explore prevalence, development, and progression of pleural effusion, and the incidence and effects of thoracentesis in adult ICU patients.

METHODS

This is a prospective observational study utilizing repeated daily ultrasonographic assessments of pleurae bilaterally, conducted in all adult patients admitted to the four ICUs of a Danish university hospital throughout a 14-day period. The primary outcome was the proportion of patients with ultrasonographically significant pleural effusion (separation between parietal and visceral pleurae >20 mm) in either pleural cavity on any ICU day. Secondary outcomes included the proportion of patients with ultrasonographically significant pleural effusion receiving thoracentesis in ICU, and the progression of pleural effusion without drainage, among others. The protocol was published before study initiation.

RESULTS

In total, 81 patients were included of which 25 (31%) had or developed ultrasonographically significant pleural effusion. Thoracentesis was performed in 10 of these 25 patients (40%). Patients with ultrasonographically significant pleural effusion, which was not drained, had an overall decrease in estimated pleural effusion volume on subsequent days.

CONCLUSION

Pleural effusion was common in the ICU, but less than half of all patients with ultrasonographically significant pleural effusion underwent thoracentesis. Progression of pleural effusion without thoracentesis showed reduced volumes on subsequent days.

Pleural effusion in critically ill patients and intensive care setting

Pleural effusion usually causes a diagnostic dilemma with a long list of differential diagnoses. Many studies found a high prevalence of pleural effusions in critically ill and mechanically ventilated patients, with a wide range of variable prevalence rates of up to 50%-60% in some studies. This review emphasizes the importance of pleural effusion diagnosis and management in patients admitted to the intensive care unit (ICU). The original disease that caused pleural effusion can be the exact cause of ICU admission. There is an impairment in the pleural fluid turnover and cycling in critically ill and mechanically ventilated patients. There are also many difficulties in diagnosing pleural effusion in the ICU, including clinical, radiological, and even laboratory difficulties. These difficulties are due to unusual presentation, inability to undergo some diagnostic procedures, and heterogenous results of some of the performed tests. Pleural effusion can affect the patient’s outcome and prognosis due to the hemodynamics and lung mechanics changes in these patients, who usually have frequent comorbidities. Similarly, pleural effusion drainage can modify the ICU-admitted patient’s outcome. Finally, pleural effusion analysis can change the original diagnosis in some cases and redirect the management toward a different way.

[Weaning from invasive ventilation : Challenges in the clinical routine]

Modern intensive care medicine is caught between the conflicting demands of an efficient but also increasingly more technical intensive care treatment with numerous therapeutic options and, at the same time, an ageing society with increasing morbidity. This is reflected, among other things, in an increasing number of ventilated patients in intensive care units and an increasing proportion of patients for whom ventilation cannot easily be discontinued. Weaning from a ventilator, which can account for more than 50% of the total ventilation time, therefore plays a central role in this process. This main topic article presents the need for strategically wise and holistic actions to minimize the consequences of invasive mechanical ventilation for patients. An attempt is made to shed more light on individual aspects of the ventilation weaning process with high relevance for clinical practice. Especially for prolonged weaning from ventilation, many more concepts are needed than simply ending ventilation.

Can Lung Ultrasound Be the Ideal Monitoring Tool to Predict the Clinical Outcome of Mechanically Ventilated COVID-19 Patients? An Observational Study

Background: During the COVID-19 pandemic, lung ultrasound (LUS) has been widely used since it can be performed at the patient’s bedside, does not produce ionizing radiation, and is sufficiently accurate. The LUS score allows for quantifying lung involvement; however, its clinical prognostic role is still controversial. Methods: A retrospective observational study on 103 COVID-19 patients with respiratory failure that were assessed with an LUS score at intensive care unit (ICU) admission and discharge in a tertiary university COVID-19 referral center. Results: The deceased patients had a higher LUS score at admission than the survivors (25.7 vs. 23.5; p-value = 0.02; cut-off value of 25; Odds Ratio (OR) 1.1; Interquartile Range (IQR) 1.0−1.2). The predictive regression model shows that the value of LUSt0 (OR 1.1; IQR 1.0–1.3), age (OR 1.1; IQR 1.0−1.2), sex (OR 0.7; IQR 0.2−3.6), and days in spontaneous breathing (OR 0.2; IQR 0.1–0.5) predict the risk of death for COVID-19 patients (Area under the Curve (AUC) 0.92). Furthermore, the surviving patients showed a significantly lower difference between LUS scores at admission and discharge (mean difference of 1.75, p-value = 0.03). Conclusion: Upon entry into the ICU, the LUS score may play a prognostic role in COVID-19 patients with ARDS. Furthermore, employing the LUS score as a monitoring tool allows for evaluating the patients with a higher probability of survival.

Risk Factors for Mortality Among Mechanically Ventilated Patients Requiring Pleural Drainage

Purpose

Pleural effusions are common in mechanically ventilated patients. However, the risk factors for poor outcomes after pleural drainage are poorly understood. This study aimed to identify factors that were associated with in-hospital mortality among mechanically ventilated patients who underwent pleural drainage.

Methods

This retrospective study evaluated 82 consecutive patients who required chest tubes during mechanical ventilation at two university-affiliated hospitals in Korea between January 2015 and June 2020.

Results

The median age was 76 years (interquartile range [IQR]: 64–84 years), and the median SOFA score was 11 (IQR: 7–13). Intensive care unit admission was most commonly because of pneumonia (n = 44, 53.7%) and 60 patients (77.9%) had exudative pleural effusions. During pleural drainage, the PaO₂/FiO₂ was 210 (IQR: 153–253); 45 patients (54.9%) were receiving vasopressors, and 31 patients (37.8%) were receiving continuous renal replacement therapy (CRRT). The multivariable regression analysis revealed that poor overall survival was independently associated with receiving vasopressors (adjusted hazard ratio [aHR]: 3.81, 95% confidence interval [CI]: 1.65–8.81, p = 0.002) and receiving CRRT (aHR: 5.48, 95% CI: 2.29–13.12, p < 0.001). The PaO₂/FiO₂ ratio was relatively stable through the third day of pleural drainage among survivors but decreased among non-survivors. The vasopressor dose decreased among survivors but remained relatively stable among non-survivors.

Conclusion

Among mechanically ventilated patients who required pleural drainage, use of vasopressors and CRRT was significantly associated with in-hospital mortality. On the third day of pleural drainage, the changes in PaO₂/FiO₂ and vasopressor dose were associated with in-hospital mortality.

Pleural Effusions in the Critically Ill and "At-Bleeding-Risk" Population

Thoracentesis is a common bedside procedure, which has a low risk of complications when performed with thoracic ultrasound and by experienced operators. In critically ill or mechanically ventilated patients, or in patients with bleeding risks due to medications or other coagulopathies, the complication rate remains low. Drainage of pleural effusion in the intensive care unit has diagnostic and therapeutic utility, and perceived bleeding risks should be one part of an individualized and comprehensive risk-benefit analysis.

Ultrasound-Guided Pleural Effusion Drainage: Effect on Oxygenation, Respiratory Mechanics, and Liberation from Mechanical Ventilation in Surgical Intensive Care Unit Patients

The question as to whether an aggressive management of post-operative pleural effusion may improve clinical outcomes after major surgery remains unanswered. The aim of this study was to investigate the effect of ultrasound-guided pleural effusion drainage on oxygenation, respiratory mechanics, and liberation from mechanical ventilation in surgical intensive care unit patients. Oxygenation and respiratory mechanics were measured before and after drainage. Over an 18-month period, a total of 62 patients were analyzed. The mean drainage volume during the first 24 h was 864 ± 493 mL, and there were no procedural complications. Both the mean PaO₂/FiO₂ ratio and lung compliance improved after drainage. Additionally, 41.9% (n = 26) of patients were ventilator-free within 72 h after drainage. Multivariable logistic regression analysis revealed that non-cardiovascular or thoracic surgery (odds ratio [OR] = 4.968, p = 0.046), a longer time interval from operation to the onset of pleural effusion (OR = 1.165, p = 0.005), and a higher peak airway pressure (OR = 1.303, p = 0.009) were independent adverse predictors for being free from mechanical ventilation within 72 h after drainage. Specifically, patients with a time from surgery to the onset of pleural effusion ≤6 days-but not those with an interval >6 days-showed a significant post-procedural improvement in terms of PaO₂/FiO₂ ratio, PaCO₂, peak airway pressure, and dynamic lung compliance. In summary, ultrasound-guided pleural effusion drainage resulted in significant clinical benefits in mechanically ventilated ICU patients after major surgery-especially in those with early-onset effusion who received thoracic surgery.

The Use of POCUS to Manage ICU Patients With COVID-19

Since the advent of SARS-CoV-2, the virus that causes COVID-19, clinicians have had to modify how they provide high-value care while mitigating the risk of viral spread. Routine imaging studies have been discouraged due to elevated transmission risk. Patients who have been diagnosed with COVID-19 often have a protracted hospital course with progression of disease. Given the need for close follow-up of patients, we recommend the use of ultrasonography, particularly point-of-care ultrasound (POCUS), to manage patients with COVID-19 through their entire ICU course. POCUS will allow a clinician to evaluate and monitor cardiac and pulmonary function, as well as evaluate for thromboembolic disease, place an endotracheal tube, confirm central venous catheter placement, and rule out a pneumothorax. If a patient improves sufficiently to perform weaning trials, POCUS can also help evaluate readiness for ventilator liberation.

Small Drainage Volumes of Pleural Effusions Are Associated with Complications in Critically Ill Patients: A Retrospective Analysis

Pleural effusions are a common finding in critically ill patients and small bore chest drains (SBCD) are proven to be efficient for pleural drainage. The data on the potential benefits and risks of drainage remains controversial. We aimed to determine the cut-off volume for complications, to investigate the impact of pleural drainage and drained volume on clinically relevant outcomes. Medical records of all critically ill patients undergoing insertion of SBCD were retrospectively examined. We screened 13,003 chest radiographs and included 396 SBCD cases in the final analysis. SBCD drained on average 900 mL, with less amount in patients with complications (p = 0.003). A drainage volume of 975 mL in 24 h represented the optimal threshold for complications. Pneumothorax was the most frequent complication (4.5%), followed by bleeding (0.8%). Female and lighter-weighted patients experienced a higher risk for any complication. We observed an improvement in the arterial partial pressure of oxygen and respiratory quotient (p < 0.001). We conclude that the small drainage volumes are associated with complications in critically ill patients—the more you drain, the safer the procedure gets. The use of SBCD is a safe and efficient procedure, further investigations regarding the higher rate of complications in female and lighter-weighted patients are desirable.

Bedside noninvasive monitoring of mechanically ventilated patients

PURPOSE OF REVIEW

Among noninvasive lung imaging techniques that can be employed at the bedside electrical impedance tomography (EIT) and lung ultrasound (LUS) can provide dynamic, repeatable data on the distribution regional lung ventilation and response to therapeutic manoeuvres.In this review, we will provide an overview on the rationale, basic functioning and most common applications of EIT and Point of Care Ultrasound (PoCUS, mainly but not limited to LUS) in the management of mechanically ventilated patients.

RECENT FINDINGS

The use of EIT in clinical practice is supported by several studies demonstrating good correlation between impedance tomography data and other validated methods of assessing lung aeration during mechanical ventilation. Similarly, LUS also correlates with chest computed tomography in assessing lung aeration, its changes and several pathological conditions, with superiority over other techniques. Other PoCUS applications have shown to effectively complement the LUS ultrasound assessment of the mechanically ventilated patient.

SUMMARY

Bedside techniques - such as EIT and PoCUS - are becoming standards of the care for mechanically ventilated patients to monitor the changes in lung aeration, ventilation and perfusion in response to treatment and to assess weaning from mechanical ventilation.

Multi-organ point-of-care ultrasound for COVID-19 (PoCUS4COVID): international expert consensus

COVID-19 has caused great devastation in the past year. Multi-organ point-of-care ultrasound (PoCUS) including lung ultrasound (LUS) and focused cardiac ultrasound (FoCUS) as a clinical adjunct has played a significant role in triaging, diagnosis and medical management of COVID-19 patients. The expert panel from 27 countries and 6 continents with considerable experience of direct application of PoCUS on COVID-19 patients presents evidence-based consensus using GRADE methodology for the quality of evidence and an expedited, modified-Delphi process for the strength of expert consensus. The use of ultrasound is suggested in many clinical situations related to respiratory, cardiovascular and thromboembolic aspects of COVID-19, comparing well with other imaging modalities. The limitations due to insufficient data are highlighted as opportunities for future research.

Feasibility and efficacy of lung ultrasound to investigate pulmonary complications in patients who developed postoperative Hypoxaemia-a prospective study

Background

Postoperative pulmonary complications (PPCs) and hypoxaemia are associated with morbidity and mortality. We aimed to evaluate the feasibility and efficacy of lung ultrasound (LUS) to diagnose PPCs in patients suffering from hypoxaemia after general anaesthesia and compare the results to those of thoracic computed tomography (CT).

Methods

Adult patients who received general anaesthesia and suffered from hypoxaemia in the postanaesthesia care unit (PACU) were analysed. Hypoxaemia was defined as an oxygen saturation measured by pulse oximetry (SPO₂) less than 92% for more than 30 s under ambient air conditions. LUS was performed by two trained anaesthesiologists once hypoxaemia occurred. After LUS examination, each patient was transported to the radiology department for thoracic CT scan within 1 h before returning to the ward.

Results

From January 2019 to May 2019, 113 patients (61 men) undergoing abdominal surgery (45 patients, 39.8%), video-assisted thoracic surgery (31 patients, 27.4%), major orthopaedic surgery (17 patients, 15.0%), neurosurgery (10 patients, 8.8%) or other surgery (10 patients, 8.8%) were included. CT diagnosed 327 of 1356 lung zones as atelectasis, while LUS revealed atelectasis in 311 of the CT-confirmed zones. Pneumothorax was detected by CT scan in 75 quadrants, 72 of which were detected by LUS. Pleural effusion was diagnosed in 144 zones on CT scan, and LUS detected 131 of these zones. LUS was reliable in diagnosing atelectasis (sensitivity 98.0%, specificity 96.7% and diagnostic accuracy 97.2%), pneumothorax (sensitivity 90.0%, specificity 98.9% and diagnostic accuracy 96.7%) and pleural effusion (sensitivity 92.9%, specificity 96.0% and diagnostic accuracy 95.1%).

Conclusions

Lung ultrasound is feasible, efficient and accurate in diagnosing different aetiologies of postoperative hypoxia in healthy-weight patients in the PACU.

Trial registration

Current Controlled Trials NCT03802175, 2018/12/05, www.ClinicalTrials.gov

Methods of estimation of pleural effusion by ecography

Pleural effusion is a frequent pathology in intensive care units. The diagnosis has improved after the introduction of pulmonary ultrasound, an accessible method at the bedside, which allows not only the diagnosis but also the treatment of this entity. The aim of our study is to determine the accuracy of published mathematical equations to calculate the volume of pleural effusion from ultrasound measurements. After doing a systematic review, seven articles were selected that each proposed a mathematical equation. In all of them the results were statistically significant. However, there is no ideal formula among those studied.

Real-time ultrasound-guided thoracentesis in the intensive care unit: prevalence of mechanical complications

Background

The use of thoracic ultrasound during thoracentesis reduces complications. The aim of this study was to determine the prevalence of complications for real-time ultrasound-guided thoracentesis performed by intensivists. As a secondary objective, the change in oxygenation before and after the procedure was evaluated.

Patients and methods

An observational prospective study was conducted. A total of 81 cases of real-time ultrasound-guided thoracentesis performed by intensivists in the intensive care unit (ICU) of Méderi Major University Hospital, Bogotá, Colombia, between August 2018 and August 2019 were analyzed. Thoracentesis performed by interventional radiologists and using techniques different from the focus of this study were excluded from the analysis.

Results

There was one pneumothorax, for a prevalence rate of mechanical complications in this population of 1.2%. The mean partial oxygen pressure to inspired oxygen fraction ratio (PaO₂/FiO₂) prior to the procedure was 198.1 (95% CI 184.75–211.45), with a PaO₂/FiO₂ after the procedure of 224.6 (95% CI 213.08–226.12) (p < 0.05).

Conclusions

Real-time ultrasound-guided thoracentesis performed by intensivists is a safe procedure and leads to a significant improvement in oxygenation rates. Future studies are required to determine the impact of these results on other outcomes, such as mortality, ICU stay, and days of mechanical ventilation.

Pleural Effusion Outcomes in Intensive Care: Analysis of a Large Clinical Database

BACKGROUND

Pleural effusions are common in critically ill patients. However, the management of pleural fluid on relevant clinical outcomes is poorly studied. We evaluated the impact of pleural effusion in the intensive care unit (ICU).

METHODS

A large observational ICU database Multiparameter Intelligent Monitoring in Intensive Care III was utilized. Analyses used matched patients with the same admission diagnosis, age, gender, and disease severity.

RESULTS

Of 50 765, 3897 (7.7%) of critically ill adult patients had pleural effusions. Compared to patients without effusion, patients with effusion had higher in-hospital (38.7% vs 31.3%, P < .0001), 1-month (43.1% vs 36.1%, P < .0001), 6-month (63.6% vs 55.7%, P < .0001), and 1-year mortality (73.8% vs 66.1%, P < .0001), as well as increased length of hospital stay (17.6 vs 12.7 days, P < .0001), ICU stay (7.3 vs 5.1 days, P < .0001), need for mechanical ventilation (63.1% vs 55.7%, P < .0001), and duration of mechanical ventilation (8.7 vs 6.3 days, P < .0001). A total of 1503 patients (38.6%) underwent pleural fluid drainage. Patients in the drainage group had higher in-hospital (43.9% vs 35.4%, P = .0002), 1-month (47.7% vs 39.7%, P = .0005), 6-month (67.1% vs 61.8%, P = .0161), and 1-year mortality (77.1% vs 72.1%, P = .0147), as well as increased lengths of hospital stay (22.1 vs 16.0 days, P < .0001), ICU stay (9.2d vs 6.4 days, P < .0001), and duration of mechanical ventilation (11.7 vs 7.1 days, P < .0001).

CONCLUSIONS

The presence of a pleural effusion was associated with increased mortality in critically ill patients regardless of disease severity. Drainage of pleural effusion was associated with worse outcomes in a large, heterogeneous cohort of ICU patients.

Thoracic ultrasonography: a narrative review

This narrative review focuses on thoracic ultrasonography (lung and pleural) with the aim of outlining its utility for the critical care clinician. The article summarizes the applications of thoracic ultrasonography for the evaluation and management of pneumothorax, pleural effusion, acute dyspnea, pulmonary edema, pulmonary embolism, pneumonia, interstitial processes, and the patient on mechanical ventilatory support. Mastery of lung and pleural ultrasonography allows the intensivist to rapidly diagnose and guide the management of a wide variety of disease processes that are common features of critical illness. Its ease of use, rapidity, repeatability, and reliability make thoracic ultrasonography the "go to" modality for imaging the lung and pleura in an efficient, cost effective, and safe manner, such that it can largely replace chest imaging in critical care practice. It is best used in conjunction with other components of critical care ultrasonography to yield a comprehensive evaluation of the critically ill patient at point of care.