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العنوان
ASSESSMENT OF DIAPHRAGMATIC MOBILITY BY CHEST ULTRASOUND IN COPD PATIENTS ON DIFFERENT MODES OF MECHANICAL VENTILATION /
المؤلف
Abd Elsamad, Ahmed Mohamed.
هيئة الاعداد
باحث / Ahmed Mohamed Abd Elsamad
مشرف / Adel Mohamed Saeed
مشرف / Ashraf Abbas ElMaraghy
مناقش / Ashraf Abbas ElMaraghy
تاريخ النشر
2019.
عدد الصفحات
177p. :
اللغة
الإنجليزية
الدرجة
ماجستير
التخصص
الطب (متفرقات)
تاريخ الإجازة
1/1/2019
مكان الإجازة
جامعة عين شمس - كلية الطب - امراض صدرية
الفهرس
Only 14 pages are availabe for public view

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Abstract

COPD is one of the classical causes of the imbalance between the ventilatory demands and the cardioneurorespiratroy capacity that eventually leads to muscle fatigue, hypercapnia and finally weaning failure; this imbalance is in part related to respiratory muscle weakness which is due to acidosis, hypercapnia, malnutrition and steroid therapy (if present), and more importantly the mechanical disadvantage that is created due to hyperinflation of the lungs; making the fibers of the inspiratory muscles act at unfavorable fiber length (shorter than the optimal length) and thus decreasing the tension generated.
Ultrasound has received increasing interest from chest physicians in recent years. Modern ultrasound devices are inexpensive, lightweight, portable and easy to be used which makes them suitable for outpatient settings as well as bedside investigation of the severely ill patients.
Extubation failure is one of the most frequently encountered events in management of patients receiving mechanical ventilation, as many as 20% of such patients require re-intubation within 72 h of extubation. A failed extubation attempt substantially prolongs the duration of mechanical ventilation, ICU stay and increases the risk of hospital mortality.
Predicting extubation outcome and preventing extubation failure is therefore an important task. Various weaning parameters have been suggested to be useful eg: rapid shallow breathing index (RSBI), maximum inspiratory pressure (Pimax), spontaneous tidal volume (VT), and trans-diaphragmatic pressure (Pdi), however the prediction rate of these parameters may not be satisfactory.
Evaluating the strength of the respiratory muscles becomes important since the imbalance between respiratory demand and supply will lead to weaning failure through the development of respiratory muscle fatigue. There have been studies evaluating the diaphragmatic function to predict weaning outcomes including: Pimax, lung volume, and inspiratory flow rate are used as surrogates for direct measuring the diaphragmatic tension, length, and shortening velocity respectively. However these methods are limited by their invasive nature and dependency on maximal voluntary efforts of the patients.
Ultrasonography has been shown to be a promising tool in evaluating the diaphragmatic function.
The aim of this work was to compare between diaphragmatic excursions in each mode of mechanical ventilation and to study the role of ultrasound in evaluating the movement of the diaphragm and its value in predicting the successful extubation in mechanically ventilated COPD patients in relation to other weaning parameters.
The present study was conducted upon 32 COPD patients in the respiratory ICU and chest department of Ain Shams University hospitals who underwent mechanical ventilation and were put on different modes (NIV, VC, BIPAP and PS).
Diaphragmatic excursions were measured throughout mechanical ventilation in each mode and were correlated with other weaning parameter as tidal volumes,RSBI and days of mechanical ventilation.
As regard weaning from mechanical ventilation, many parameters were used to assess the patients as: tidal volume (VT), with sensitivity of 87.5%, specificity of 75% using a cutoff point 370 ml , rapid shallow breathing index (RSBI), with sensitivity of 95.83 %, specificity of 87.5 % using a cutoff point 97breaths/min/L and days of mechanical ventilation with a cutoff point 8 days with sensitivity 91.67 % and specificity 75%
Also the prediction rate of these parameters may not be satisfactory so evaluating the diaphragmatic displacement became important. Evaluation of diaphragmatic displacement had been traditionally performed using fluoroscopy. Although this method was considered to be the gold standard but it had some limitations such as: visualization of the diaphragm through a single incidence, need for corrective calculations and exposure of the patients to ionizing radiations.
In recent years, ultrasound has also been used to evaluate the diaphragmatic mobility as it offers some advantages over fluoroscopy including the lack of ionizing radiation and the possibility of its usage at the bedside of the patients, and direct quantification of the movement of the diaphragm., soultrasound has been shown to be a promising tool in evaluating the diaphragmatic function.
In this study the mean displacement of the diaphragm measured by the ultrasound during weaning from mechanical ventilation in COPD patients in different modes of mechanical ventilation till weaning ( NIV,VC,BIPAP and PS ) with sensitivity and specificity (83.3%,66.7%),(79.17%,75%),(91.67%,87.5%) and (95.83%,87.5%) using cutoff points 1.4,1.3,1.5, and 1.6 cm respectively .
In the present study, there is a significant relationship between diaphragmatic displacement measured by ultrasound, tidal volume and success of weaning, and a significant inverse relationship, days of mechanical ventilation, RSBI and with no relation to age.
Parameters of weaning including tidal volume, RSBI and diaphragmatic displacement were significantly better in the group of successful weaning.
Using ROC curve, AUC was best with BIPAP mode followed by PS mode then VC mode and finally NIV mode that suggest better diaphragmatic excursions in BIPAP and PS modes for COPD patients.
Diaphragmatic displacement measured by ultrasound is one of the most sensitive, specific and accurate parameters for weaning of COPD patients from mechanical ventilation, especially in relationship with the other weaning parameters as tidal volume, RSBI, and days of mechanical ventilation should be kept in consideration during weaning from mechanical ventilation.
Ultrasound in the evaluation of motion of the diaphragm is an accurate technique that has had no technical failures and is relatively easy to master. The modality is portable, which is very important for many seriously ill patients receiving mechanical ventilation, and uses no ionizing radiation. It should be the modality of choice in the examination of motion of the diaphragm