A Simplified Lung Ultrasound Guided Management Protocol Of Pulmonary Congestion in Hemodialysis

Overview

Pulmonary congestion secondary to volume overload or interstitial tissue inflammation is common in chronic hemodialysis patients. This pulmonary congestion occurs mainly during the period between dialysis sessions and is an independent risk factor for cardiovascular event morbidity and mortality in this population. The evaluation of this pulmonary congestion and the estimation of the dry weight of hemodialysis patients according to conventional methods represent a real challenge for clinical nephrologists. Lung ultrasound is a new diagnostic approach validated in the assessment of pulmonary congestion. It would allow a better assessment of dry weight in chronic hemodialysis patients based on the results of preliminary studies, including our latest pilot study. However, there is little evidence comparing this novel approach to traditional approaches.

The classic treatment program for hemodialysis patients includes three sessions per week on fixed days (Monday-Wednesday-Friday or Tuesday-Thursday-Saturday or Sunday). Hemodialysis patients with end-stage renal disease often develop fluid overload between dialysis sessions due to decreased diuresis or anuria. This overload is manifested by pulmonary congestion, which is an independent risk factor for morbidity and mortality from cardiovascular events in these patients. Studies show pulmonary congestion is not always associated with increased left ventricular filling pressure. Patients with end-stage renal disease also have impaired capillary permeability secondary to the dialysis filters used (synthetic membranes) and uremic syndromes, which increases their risk of cardiopulmonary complications. In addition, some experimental studies show that inflammatory mechanisms can also cause capillary changes and increase the risk of pulmonary edema in patients with end-stage renal disease with fluid overload. Evaluating fluid overload and estimating the dry weight of hemodialysis patients. According to conventional methods, namely pulmonary auscultation, chest radiography, cardiac ultrasound, and blood pressure measurement, this represents a real challenge for clinical nephrologists. Hyper- or hypo-hydration in hemodialysis patients, especially if it persists over time, is linked to adverse cardiovascular consequences. The investigators currently know that this increase in extravascular fluid in the lungs creates an air-liquid interface that induces an ultrasound artifact in continuous lines called B-lines, which ultrasound machines can detect. It has been shown that the presence of these B-lines alone in hemodialysis patients is an independent risk factor for mortality and cardiovascular events. Their sensitivity is high and can be detected even at the subclinical stage. Similarly, in hemodialysis patients with high blood pressure, the modification of dry weight according to these B-lines has demonstrated a beneficial effect on blood pressure control and cardiac parameters. It should be noted that these B-lines are not specific for water overload and can be the consequence of several pathologies, such as interstitial pneumonia or diffuse pulmonary fibrosis. Lung ultrasound is a new diagnostic approach validated in the assessment of pulmonary congestion. According to recent preliminary reports, it would allow a better estimate of volume expansion and, therefore, a better assessment of dry weight in chronic hemodialysis patients. However, little evidence compares this novel approach to conventional standardized approaches. No study has defined the best moment to do a lung ultrasound to obtain the most reliable pulmonary congestion level. The investigators did this in our pilot study and concluded that the best moment was after the second dialysis session. Based on that, and in order to establish a management and monitoring protocol, the study aimed to show that reducing dry weight. According to lung ultrasound at that particular moment, it is the best way to manage pulmonary congestion in this population. Dialysis service in Qatar is provided by Hamad Medical Corporation facilities. The investigators have seven units providing ambulatory dialysis care. Currently, The investigators have about 1000 hemodialysis (HD) patients. The largest center with over 500 patients is Fahad Bin Jassim Kidney Center (FBJKC). Our current practice is to estimate dry weight on a monthly basis during the monthly evaluation of HD patients by our nephrologist. This evaluation depends on physical examination, blood pressure, and other clinical parameters. Sometimes, it is very difficult to estimate the dry weight (obesity, bedbound or wheelchair-dependent patients, congestive heart failure, etc.). Introducing new technology to guide the estimation of dry weight provides great service to our HD patients. It can help in estimating dry weight, especially in difficult cases. Lung ultrasound to evaluate congestion is a newly introduced technology to help estimate dry weight. Implementing this technology might offer valued service to improve care to our HD patients in Qatar. I want to highlight the importance of this study to our dialysis service in Qatar. In addition to the specified novel approach mentioned in the methods and outcomes, the investigators have many goals to serve dialysis services in Qatar. The investigators will introduce Lung US volume assessment (currently not done) with the training needed and validate the best way of utilizing it to serve our patients. The investigators will also introduce ambulatory home blood pressure measurement (currently not done in dialysis) with all the training needed for our service and the best way to apply it. This study has scientific and practical values on the research ground with the expected immediate impact on our dialysis service.