Ultrasonographic evaluation of diaphragmatic motion.

Abstract

Objective. To evaluate the technical feasibility and utility of ultrasonography in the study of diaphragmatic motion at our institution. Methods. The study consisted of 2 parts. For part I, in 23 volunteers we performed 23 studies on 46 hemidiaphragms with excursions documented on M-mode ultrasonography. For part II, in 22 patients we performed 52 studies in 102 hemidiaphragms. In 50 studies both hemidiaphragms were studied, and in another 2 studies only 1 hemidiaphragm was studied. Patients' ages ranged from birth to 66 years (mean, 23 years). There were 16 male and 6 female patients. Indications for the study were (1) suggestion of paralysis of the diaphragm (n = 22); (2) if the diaphragm was already known to be paralyzed, for evaluation of response to phrenic nerve or pacer stimulation (n = 9); and (3) follow-up of previous findings (n = 21). Patients were examined in the supine position in the longitudinal semicoronal plane from a subcostal or low intercostal approach. Motion was documented with real-time ultrasonography and measured with M-mode ultrasonography. Results. Of the 102 clinical hemidiaphragms studied, findings included normal motion (n = 42), decreased motion (n = 22), no motion (n = 6), paradoxical motion (n = 10), positive pacer response (n = 13), negative pacer response (n = 2), positive phrenic stimulation (n = 6), and negative phrenic stimulation (n = 1). There were no failures of visualization. Conclusions. Ultrasonography proved feasible and useful in evaluating diaphragmatic motion. In our practice it has replaced fluoroscopy. Ultrasonography has advantages over traditional fluoroscopy, including portability, lack of ionizing radiation, visualization of structures of the thoracic bases and upper abdomen, and the ability to quantify diaphragmatic motion.

B-Mode Ultrasound Assessment of Diaphragm Structure and Function in Patients With COPD

“…9 Th at study confi rmed the fi ndings of prior smaller studies and provided normal values for future comparative studies; however, we did not know whether these values could be applied to the population of patients with COPD. 5,[12][13][14][15] We hypothesized that patients with moderate COPD would demonstrate compensatory overuse hypertrophy of the diaphragm and that patients with severe air trapping would have impaired diaphragm contractility because of the displacement of the muscle and subsequent suboptimal length-tension relationship of the muscle fi bers, resulting in a decreased thickening ratio. Contrary to our hypotheses, our results show that patients with COPD have comparable diaphragm thickness and contraction to that of normal subjects.…”

“…We now use it routinely in our EMG laboratory in the workup of patients with shortness of breath, not only to enhance the safety and accuracy of needle EMG of the diaphragm, 4 but also to evaluate for atrophy and lack of motion of the muscle, which are readily apparent on ultrasound in patients with phrenic neuropathy. [5][6][7][8] Sonographic assessment of diaphragm structure and function would be a useful clinical tool in patients with COPD presenting for evaluation of possible coexisting neuromuscular respiratory weakness, particularly because needle EMG is relatively contraindicated in this patient population due to the potential for lung hyperinfl ation and associated diffi culty involved in accurately localizing the muscle. However, to use ultrasound in this way, there is a need for normal values for diaphragm thickness and contraction in patients with COPD.…”

Bedside US imaging in multiple trauma patients. Part 1: US findings and techniques

“…In case of esophageal intubation (occurring in 15 % of cases), the endotracheal tube can be visualized directly in the esophagus (on transverse scans posterior to the left lobe of the thyroid) due to the appearance of a second interface, referred to as a ''double airway tract'' in the esophagus, or by gently moving the tube up and down. The diaphragm and lung movements, which are qualitative and quantitative signs that the lungs are properly ventilated, can be directly and easily documented by US [16]. If the movements of the diaphragm are symmetrical on both sides, and intercostal US scan shows the presence of bilateral lung sliding synchronous with the ventilation, it can be inferred that the endotracheal tube is correctly placed in the trachea [17,18].…”

Ultrasound in obstructive lung diseases: the effect of airway obstruction on diaphragm kinetics. A short pictorial essay

“…In M-mode representation diaphragm appears as a thick hyperechoic line approaching to the probe in inspiration and moving away from the probe in expiration. This visualization of diaphragm, although with different approaches, has been described by some authors [12][13][14][15][16][17][18][19]. The right hemidiaphragm can be studied in most cases by this approach; meanwhile the left dome could be often masked by artifacts generated by air in bowel and stomach [12].…”