Pleural effusions in the intensive care unit

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.

Clinically Significant Pleural Effusion in Intensive Care: A Prospective Multicenter Cohort Study

OBJECTIVES

The prevalence and optimal management of clinically significant pleural effusion, confirmed by thoracic ultrasound, in the critically ill is unknown. This study aimed to determine: 1) the prevalence, characteristics, and outcomes of patients treated in intensive care with clinically significant effusion and 2) the comparative efficacy and safety of pleural drainage or expectant medical management.

DESIGN

A prospective multicenter cohort study.

SETTING

ICUs in four teaching hospitals in Western Australia.

PATIENTS

Consecutive patients with clinically significant pleural effusions (depth ≥ 2 cm on thoracic ultrasound with clinician-determined adverse effects on patient progress).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Primary outcome was the change in Pao2:Fio2 (mm Hg) ratio from baseline to 24 hours. Changes in diagnosis and treatment based on pleural fluid analysis and pleural effusion related serious adverse events between those who underwent either drainage within 24 hours or expectant management were compared. Of the 7,342 patients screened, 226 patients (3.1%) with 300 pleural effusions were enrolled. Early drainage of pleural effusion occurred in 76 patients (34%) and significantly improved oxygenation (Pao2:Fio2 ratio 203 at baseline vs 263 at 24 hr, +29.6% increment; p < 0.01). This was not observed in the other 150 patients who had expectant management (Pao2:Fio2 ratio 250 at baseline vs 268 at 24 hr, +7.2% increment; p = 0.44). The improvement in oxygenation after early drainage remained unchanged after adjustment for a propensity score on the decision to initiate early drainage. Pleural effusion related serious adverse events were not different between the two groups (early drainage 10.5% vs no early drainage 16.0%; p = 0.32). Improvements in diagnosis were noted in 91 initial (nonrepetitive) drainages (76.5% out of 119); treatment strategy was optimized after 80 drainage episodes (59.7% out of 134).

CONCLUSIONS

Early drainage of clinically significant pleural effusion was associated with improved oxygenation and diagnostic accuracy without increased complications.

Utility of pleural effusion drainage in the ICU: An updated systematic review and META-analysis

PURPOSE

The effects on the respiratory or hemodynamic function of drainage of pleural effusion on critically ill patients are not completely understood. First outcome was to evaluate the PiO₂/FiO₂ (P/F) ratio before and after pleural drainage.

SECONDARY OUTCOMES

evaluation of A-a gradient, End-Expiratory lung volume (EELV), heart rate (HR), mean arterial pressure (mAP), left ventricular end-diastolic volume (LVEDV), stroke volume (SV), cardiac output (CO), ejection fraction (EF), and E/A waves ratio (E/A). A tertiary outcome: evaluation of pneumothorax and hemothorax complications.

MATERIALS AND METHODS

Searches were performed on MEDLINE, EMBASE, COCHRANE LIBRARY, SCOPUS and WEB OF SCIENCE databases from inception to June 2018 (PROSPERO CRD42018105794).

RESULTS

We included 31 studies (2265 patients). Pleural drainage improved the P/F ratio (SMD: -0.668; CI: -0.947-0.389; p < .001), EELV (SMD: -0.615; CI: -1.102-0.219; p = .013), but not A-a gradient (SMD: 0.218; CI: -0.273-0.710; p = .384). HR, mAP, LVEDV, SV, CO, E/A and EF were not affected. The risks of pneumothorax (proportion: 0.008; CI: 0.002-0.014; p = .138) and hemothorax (proportion: 0.006; CI: 0.001-0.011; p = .962) were negligible.

CONCLUSIONS

Pleural effusion drainage improves oxygenation of critically ill patients. It is a safe procedure. Further studies are needed to assess the hemodynamic effects of pleural drainage.

An easier and safe affair, pleural drainage with ultrasound in critical patient: a technical note

Thoracic ultrasound is a powerful diagnostic imaging technique for pleural space disorders. In addition to visualising pleural effusion, thoracic ultrasound also helps clinicians to identify the best puncture site and to guide the drainage insertion procedure. Thoracic ultrasound is essential during these invasive manoeuvres to increase safety and decrease potential life-threatening complications. This paper provides a technical description of pigtail-type drainage insertion using thoracic ultrasound, paying particular attention to indications, contraindications, ultrasound guidance, preparation/equipment, procedure and complications.

Ultrasonographic quantification of pleural effusion: comparison of four formulae

PURPOSE

The purpose of this study was to evaluate the correlations of ultrasonographically estimated volumes of pleural fluid with the actual effusion volume in order to determine the most reliable formula.

METHODS

In 32 consecutive patients with clinically diagnosed pleural effusion, an ultrasound estimation was made of the volume of effusion using four different formulae, including two in the erect position and two in the supine position. Closed-tube thoracostomy drainage using a 28-Fr chest tube was performed. The total drainage was calculated after confirmation of full lung re-expansion and complete drainage by plain chest radiographs and ultrasound. The ultrasonographically estimated volume was compared to the actual total volume drained as the gold standard.

RESULTS

There were 14 female and 18 male subjects. The mean age of all subjects was 41.56±18.34 years. Fifty percent of the effusions were in the left hemithorax. Metastatic disease accounted for the plurality of effusions (31.2%). The mean total volume drained for all the subjects was 2,770±1,841 mL. The ultrasonographically estimated volumes for the erect 1, erect 2, supine 1, and supine 2 formulae were 1,816±753 mL, 1,520±690 mL, 2,491±1,855 mL, and 1,393±787 mL, respectively. The Pearson correlation coefficients (r) for the estimate of each formula were 0.75, 0.81, 0.62, and 0.63, respectively.

CONCLUSION

Although both erect formulae showed similar correlations, the erect 2 formula (Goecke 2) was most closely correlated with the actual volume drained.

Bedside pleuroscopy in the Intensive Care Unit

Objectives:

It is not always possible to move critically ill patients to the operating or endoscopy room for a pleuroscopy. Bedside pleuroscopy is indicated for these patients. The aim of this study was to investigate the safety and complications of bedside pleuroscopy in an Intensive Care Unit (ICU).

Materials and Methods:

The patients who had undergone routine examinations for pleural effusion, with no established diagnosis at the previous admission were included in this analysis. Patients received local analgesia with bedside pleuroscopy performed by a chest physician in the ICU with continuous monitoring.

Results:

Twenty-five patients (17 males and 8 females) with a mean age of 74 ± 3 years were enrolled. Their mean APACHE II score was 23 ± 1. The duration of drainage from the pigtail catheter was a mean 3.9 ± 0.2 days, and mean ventilator usage was 6 ± 0.7 days. The length of stay in the ICU was 11 ± 1 days. Most pleural effusions occurred on the right side (17/25, 68%). Fifteen patients (60%) had malignant effusions, four (16%) had parapneumonic effusions, three (12%) had empyema, and two (8%) had tuberculosis. Complications occurred in 11 (44%) patients. There were no major complications such as bleeding or procedure-related death. The most common complication was transient chest pain (n = 6, 24%).

Conclusions:

Pleuroscopy performed at the bedside in the ICU is a simple and safe procedure. It has the potential for use in critical patients as serious complications are rare.

Thoracic ultrasound for pleural effusion in the intensive care unit: a narrative review from diagnosis to treatment

Pleural effusion (PLEFF), mostly caused by volume overload, congestive heart failure, and pleuropulmonary infection, is a common condition in critical care patients. Thoracic ultrasound (TUS) helps clinicians not only to visualize pleural effusion, but also to distinguish between the different types. Furthermore, TUS is essential during thoracentesis and chest tube drainage as it increases safety and decreases life-threatening complications. It is crucial not only during needle or tube drainage insertion, but also to monitor the volume of the drained PLEFF. Moreover, TUS can help diagnose co-existing lung diseases, often with a higher specificity and sensitivity than chest radiography and without the need for X-ray exposure. We review data regarding the diagnosis and management of pleural effusion, paying particular attention to the impact of ultrasound. Technical data concerning thoracentesis and chest tube drainage are also provided.

Thoracentesis outcomes: a 12-year experience

BACKGROUND

Despite a lack of evidence in the literature, several assumptions exist about the safety of thoracentesis in clinical guidelines and practice patterns. We aimed to evaluate specific demographic and clinical factors that have been commonly associated with complications such as iatrogenic pneumothorax, re-expansion pulmonary oedema (REPE) and bleeding.

METHODS

We performed a cohort study of inpatients who underwent thoracenteses at Cedars-Sinai Medical Center (CSMC) from August 2001 to October 2013. Data were collected prospectively including information on volume of fluid removed, procedure side, whether the patient was on positive pressure ventilation, number of needle passes and supine positioning. Iatrogenic pneumothorax, REPE and bleeding were tracked for 24 h after the procedure or until a clinical question was reconciled. Demographic and clinical characteristics were obtained through query of electronic medical records.

RESULTS

CSMC performed 9320 inpatient thoracenteses on 4618 patients during the study period. There were 57 (0.61%) iatrogenic pneumothoraces, 10 (0.01%) incidents of REPE and 17 (0.18%) bleeding episodes. Iatrogenic pneumothorax was significantly associated with removal of >1500 mL fluid (p<0.0001), unilateral procedures (p=0.001) and more than one needle pass through the skin (p=0.001). For every 1 mL of fluid removed there was a 0.18% increased risk of REPE (95% CI 0.09% to 0.26%). There were no significant associations between bleeding and demographic or clinical variables including International Normalised Ratio, partial thromboplastin time and platelet counts.

CONCLUSIONS

Our series of thoracenteses had a very low complication rate. Current clinical guidelines and practice patterns may not reflect evidence-based best practices.

Pleural effusion in patients with acute lung injury: a CT scan study

OBJECTIVES

Pleural effusion is a frequent finding in patients with acute respiratory distress syndrome. To assess the effects of pleural effusion in patients with acute lung injury on lung volume, respiratory mechanics, gas exchange, lung recruitability, and response to positive end-expiratory pressure.

DESIGN, SETTING, AND PATIENTS

A total of 129 acute lung injury or acute respiratory distress syndrome patients, 68 analyzed retrospectively and 61 prospectively, studied at two University Hospitals.

INTERVENTIONS

Whole-lung CT was performed during two breath-holding pressures (5 and 45 cm H2O). Two levels of positive end-expiratory pressure (5 and 15 cm H2O) were randomly applied.

MEASUREMENTS

Pleural effusion volume was determined on each CT scan section; respiratory system mechanics, gas exchange, and hemodynamics were measured at 5 and 15 cm H2O positive end-expiratory pressure. In 60 patients, elastances of lung and chest wall were computed, and lung and chest wall displacements were estimated.

RESULTS

Patients were divided into higher and lower pleural effusion groups according to the median value (287 mL). Patients with higher pleural effusion were older (62±16 yr vs. 54±17 yr, p<0.01) with a lower minute ventilation (8.8±2.2 L/min vs. 10.1±2.9 L/min, p<0.01) and respiratory rate (16±5 bpm vs. 19±6 bpm, p<0.01) than those with lower pleural effusion. Both at 5 and 15 cm H2O of positive end-expiratory pressure PaO2/FIO2, respiratory system elastance, lung weight, normally aerated tissue, collapsed tissue, and lung and chest wall elastances were similar between the two groups. The thoracic cage expansion (405±172 mL vs. 80±87 mL, p<0.0001, for higher pleural effusion group vs. lower pleural effusion group) was greater than the estimated lung compression (178±124 mL vs. 23±29 mL, p<0.0001 for higher pleural effusion group vs. lower pleural effusion group, respectively).

CONCLUSIONS

Pleural effusion in acute lung injury or acute respiratory distress syndrome patients is of modest entity and leads to a greater chest wall expansion than lung reduction, without affecting gas exchange or respiratory mechanics.

Dynamic and volumetric variables reliably predict fluid responsiveness in a porcine model with pleural effusion

Background

The ability of stroke volume variation (SVV), pulse pressure variation (PPV) and global end-diastolic volume (GEDV) for prediction of fluid responsiveness in presence of pleural effusion is unknown. The aim of the present study was to challenge the ability of SVV, PPV and GEDV to predict fluid responsiveness in a porcine model with pleural effusions.

Methods

Pigs were studied at baseline and after fluid loading with 8 ml kg⁻¹ 6% hydroxyethyl starch. After withdrawal of 8 ml kg⁻¹ blood and induction of pleural effusion up to 50 ml kg⁻¹ on either side, measurements at baseline and after fluid loading were repeated. Cardiac output, stroke volume, central venous pressure (CVP) and pulmonary occlusion pressure (PAOP) were obtained by pulmonary thermodilution, whereas GEDV was determined by transpulmonary thermodilution. SVV and PPV were monitored continuously by pulse contour analysis.

Results

Pleural effusion was associated with significant changes in lung compliance, peak airway pressure and stroke volume in both responders and non-responders. At baseline, SVV, PPV and GEDV reliably predicted fluid responsiveness (area under the curve 0.85 (p<0.001), 0.88 (p<0.001), 0.77 (p = 0.007). After induction of pleural effusion the ability of SVV, PPV and GEDV to predict fluid responsiveness was well preserved and also PAOP was predictive. Threshold values for SVV and PPV increased in presence of pleural effusion.

Conclusions

In this porcine model, bilateral pleural effusion did not affect the ability of SVV, PPV and GEDV to predict fluid responsiveness.

The diagnosis and management of pleural effusions in the ICU

Pleural effusions are common in critically ill patients. Most effusions in intensive care unit (ICU) patients are of limited clinical significance; however, some are important and require aggressive management. Transudative effusions in the ICU are commonly caused by volume overload, decreased plasma oncotic pressure, and regions of altered pleural pressure attributable to atelectasis and mechanical ventilation. Exudates are sequelae of pulmonary or pleural infection, pulmonary embolism, postsurgical complications, and malignancy. Increases in pleural fluid volume are accommodated principally by chest wall expansion and, to a lesser degree, by lung collapse. Studies in mechanically ventilated patients suggest that pleural fluid drainage can result in improved oxygenation for up to 48 hours, but data on clinical outcomes are limited. Mechanically ventilated patients with pleural effusions should be semirecumbant and treated with higher levels of positive-end expiratory pressure. Rarely, large effusions can cause cardiac tamponade or tension physiology, requiring urgent drainage. Bedside ultrasound is both sensitive and specific for diagnosing pleural effusions in mechanically ventilated patients. Sonographic findings of septation and homogenous echogenicity may suggest an exudative effusion, but definitive diagnosis requires pleural fluid sampling. Thoracentesis should be carried out under ultrasound guidance. Antibiotic regimens for parapneumonic effusions should be based on current pneumonia guidelines, and anaerobic coverage should be included in the case of empyema. Decompression of the pleural space may be necessary to improve respiratory mechanics, as well as to treat complicated effusions. While small-bore catheters inserted under ultrasound guidance may be used for nonseptated effusions, surgical consultation should be sought in cases where this approach fails, or where the effusion appears complex and septated at the outset. Further research is needed to determine the effects of pleural fluid drainage on clinical outcomes in mechanically ventilated patients, to evaluate weaning strategies that include pleural fluid drainage, and to better identify patients in whom pleural effusions are more likely to be infected.

Hemothorax in a medical intensive care unit: incidence, comorbidity and prognostic factors

BACKGROUND/PURPOSE

There is a lack of data regarding the occurrence of hemothorax in medical intensive care units (ICUs). The purpose of this study was to investigate the incidence, comorbidity and prognostic factors of hemothorax in medical ICU patients.

METHODS

From January 1997 to December 2004, patients with hemothorax that developed during an ICU stay were studied. Hemothorax was considered procedure-related if it developed within 24 hours after an invasive procedure. Medical records were reviewed and analyzed with respect to patients' demographic data, underlying diseases, reasons for admission, Acute Physiology and Chronic Health Evaluation II score, procedures related to hemothorax, management, duration of ICU stay, and outcomes.

RESULTS

Fifty-three patients (0.79%) suffered hemothorax during their ICU stay. Chronic kidney disease (77.4%) was the most common comorbidity. A total of 40 cases (75.5%) were procedure-related. Thoracentesis and chest tube thoracostomy were the most common procedures. The 28-day mortality rate was 35.8%. Multivariate logistic regression analysis revealed that a prothrombin time/international normalized ratio > or = 1.6 (odds ratio = 10.99, 95% confidence interval = 1.08-112.05) and a hemoglobin decrease > or = 3 g/dL (odds ratio = 5.55, 95% confidence interval = 1.26-24.45) were significantly associated with 28-day mortality.

CONCLUSION

Chronic kidney disease was the most common comorbidity associated with hemothorax. Patients with chronic kidney disease might require close observation for hemothorax after invasive procedures, such as thoracentesis and chest tube thoracostomy. Prolonged prothrombin time and decreased hemoglobin level might be of prognostic value for critically ill patients with hemothorax.

The use of point-of-care bedside lung ultrasound significantly reduces the number of radiographs and computed tomography scans in critically ill patients

BACKGROUND

Chest radiography has been reported to have low diagnostic accuracy in critically ill intensive care unit (ICU) patients, and chest computed tomography (CT) scans require patients to be transported out of the ICU, putting them at risk of adverse events. In this study we assessed the efficacy of routine bedside lung ultrasound (LUS) in the evaluation of pleural effusions (PE) in the ICU.

METHODS

Three hundred seventy-six patients admitted to the ICU for major trauma (46.3%), medical pathology (41.5%), and postsurgical complications (12.2%) (May 2008 to April 2009) were included in this study. Patients were placed into either the control group (group C) or the study group (group S), on the basis of the introduction of routine LUS performed by a single group of intensivists in 1 tertiary care ICU. To reduce provider bias, the physicians conducting the LUS were not aware of the study. Collected data included patient demographics, clinical course, and number of chest radiographs and CT scans performed. As a secondary goal, we assessed the reliability of Balik's formula in PE estimation.

RESULTS

No significant differences were found between the 2 groups with regard to their demographics and ICU clinical course. Group S had a significant reduction in the total number of chest radiographs obtained (-26%; P < 0.001) and CT scans (-47%; P < 0.001) in comparison with the comparison group C. A 6-month follow-up analysis of the ICU LUS protocol revealed a time-dependent decrease in the number of radiological examinations requested for patients with PE. Lastly, PE volume estimation using the LUS and Balik's formula correlates well with the effective volume drained (r = 0.65; P < 0.0001).

CONCLUSIONS

Routine use of LUS in the ICU setting can be associated with a reduction of the number of chest radiographs and CT scans performed.

Ultrasound estimation of volume of postoperative pleural effusion in cardiac surgery patients

The aim of this study was to establish a practical simplified formula to facilitate the management of a frequently occurring postoperative complication, pleural effusion. Chest ultrasonography with better sensitivity and reliability in the diagnosis of pleural effusions than chest X-ray can be repeated serially at the bedside without any radiation risk. One hundred and fifty patients after cardiac surgery with basal pleural opacity on chest X-ray have been included in our prospective observational study during a two-year period. Effusion was confirmed on postoperative day (POD) 5.9+/-3.2 per chest ultrasound sonography. Inclusion criteria for subsequent thoracentesis based on clinical grounds alone and were not protocol-driven. Major inclusion criteria were: dyspnea and peripheral oxygen saturation (SpO(2)) levels < or = 92% and the maximal distance between mid-height of the diaphragm and visceral pleura (D > or = 30 mm). One hundred and thirty-five patients (90%) were drained with a 14-G needle if according to the simplified formula: V (ml)=[16 x D (mm)] the volume of the pleural effusion was around 500 ml. The success rate of obtaining fluid was 100% without any complications. There is a high accuracy between the estimated and drained pleural effusion. Simple quantification of pleural effusion enables time and cost-effective decision-making for thoracentesis in postoperative patients.

Diagnosis and management of pleural effusions: a practical approach

Pleural effusion is defined as an abnormal amount of pleural fluid accumulation in the pleural space and is the result of an imbalance between excessive pleural fluid formation and pleural fluid absorption. Although the list of causes of pleural effusions is extensive, the great majority of the cases are caused by pneumonia, congestive heart failure, and malignancy. In this article, we provide an overview of the most common causes of pleural effusions likely to be encountered by the general practitioner, and a practical approach to the diagnosis and management of this common condition.

Anaesthetic and intensive care management of a patient with Ehlers-Danlos type IV syndrome after laparotomy

A 31-year-old woman with Ehlers-Danlos type IV syndrome developed multiple intensive care related complications following laparotomy for perforated bowel. Complications are more likely to occur with the Ehlers-Danlos syndrome.