الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 136 |  |  |
| | | from | 136 | | |
Abstract
The end-stage renal disease (ESRD) is characterized by a profound impairment in the regulatory system of body fluid with important aftermath in terms of survival for the risk of acute and chronic volume overload. Consequently, volume assessment in hemodialysis is one of the primary goals, often challenging, that is to be achieved by the nephrologist and intensivist.
Before hemodialysis (HD), about 60% of ESRD patients displayed moderate-severe lung congestion and this alteration is frequently asymptomatic. Lung congestion is reduced but not abolished by ultrafiltration dialysis, and about one third to one fourth of patients still have excessive lung water after dialysis.
Extravascular lung water is a relatively small but fundamental component of body fluids volume. This component represents the water content of the lung interstitium that is strictly dependent on the filling pressure of the left ventricle (LV), that is, the hemodynamic parameter considered as the golden standard for guiding fluids therapy in critical care.
Due to limitations of physical exam in precise assessment of volume status, a multitude of objective methods (e.g., natriuretic peptides, blood volume monitoring, and bioimpedance spectroscopy) have been explored to guide the ultrafiltration process during dialysis therapy.
Unfortunately, these methods have serious limitations and so far, none of them has shown promising results when used in isolation.
Point-of-care ultrasonography has recently emerged as an intriguing adjunct to physical examination. Lung ultrasound, is a non-invasive, easy-to-perform, radiation-free, fast, cheap, and highly reliable technique, which is currently employed for objective monitoring of pulmonary congestion. The technique requires ultrasound scanning of the anterior right and left chest, from the second to the fifth intercostal space, in multiple intercostal spaces.
Also, Measuring IVC diameter changes before and after hemodialysis sessions shows the feasibility and usefulness of the examination in HD patients
The study is aimed to evaluate the sensitivity and specificity of chest ultrasound to detect lung congestion in dialysis patients.
This is a prospective clinical study, was conducted at the Critical care department, Benha university hospital, on 100 hemodialysis patients. All patients were subjected to detailed history taking and physical examination. Blood pressure, HR and RR was checked pre and post dialysis. Routine laboratory tests were done (Hb, serum urea, serum creatinine, full electrolytes)
Lung ultrasound was performed with a portable ultrasound General Electric machine with linear probe. The same operator did the ultrasound pre and post hemodialysis in the same areas of the chest to reduce the bias
Ultrasound examination of the anterolateral chest was carried out with longitudinal scan in the intercostal spaces of the right and left hemi thoraces, we evaluate (4) sonographic lung zones on each side. We divided chest examination to anterior chest wall from midline to anterior axillary line and lateral chest wall examination from anterior axillary line to posterior axillary line. Each part was divided into upper and lower zone, upper zone includes 2nd, 3rd, and 4th intercostal spaces (on the right side also includes 5th intercostal space). Lower zone includes intercostal spaces below 5th space on the right side and 4th space on the left side.
IVC diameter was measured at a point 2 cm from its entry into the right atrium, where its walls are most parallel. Each measurement was made thrice, and the average value recorded. Measurements of IVC was done by the same operator in the same site pre and post HD.
Based on these results, there is significant change of B-lines and IVC diameter in the study patients pre dialysis and post dialysis.
Lung ultrasound can be considered a good modality for volume assessment in hemodialysis patients. Also, measuring IVC diameter before and after dialysis can be used as adjuvant tool with chest ultrasound in assessment of volume status in ESRD patients
We recommend further meta-analysis studies with long term follow up to evaluate lung ultrasound in hemodialysis patients.
We should acknowledge some limitations of this study:
1. It is a single-center study with a relatively small number of enrolled patients.
2. Being an ultrasound evaluation, LUS shares all limitations related to an operator-dependent technique. It is also true that since the examination is much simpler than other ultrasound applications (i.e., echocardiography, abdominal ultrasound, etc.), the inter-operator variability is low.
3. B-lines are a non-specific sign of pulmonary interstitial syndrome; therefore, they can be visible also in different conditions, such as pulmonary fibrosis, acute respiratory distress syndrome, interstitial pneumonia. In our population we excluded patients with these significant pulmonary conditions. In larger populations in the clinical arena, this lack of specificity may pose some issues, especially when the pre-existent pulmonary condition is not known. It is especially in patients with pulmonary fibrosis or other pulmonary interstitial syndromes that B-lines cannot be used to reliably evaluate pulmonary congestion.
4. Lung ultrasound cannot be used for assessment of hypovolemia, and it is difficult to be done in morbidly obese patients.