DIAPHRAGMATIC PARALYSIS: M mode US and SNIFF TEST

Abstract

To evaluate the technical feasibility and utility of ultrasonography in the study of diaphragmatic motion at our institution.

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.

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.

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.

DIAPHRAGMATIC PARALYSIS at MEDIC CENTER

 

Objectives:

To evaluate the use of M mode ultrasonography in the evaluation of diaphragmatic paralysis in adults.

Setting:

Radiology department, Princess Alexandra Hospital, Brisbane, Australia.

Methods:

Ten patients who were referred for evaluation of suspected diaphragmatic paralysis were evaluated using M mode ultrasound.

Results:

Three of the patients who were scanned demonstrated normal diaphragmatic movement. The M mode trace demonstrated normal movement of the diaphragm bilaterally with quiet respiration and a sharp upstroke on the sniff test (indicating normal caudal movement of the diaphragm). Six patients were found to have a unilateral diaphragmatic paralysis. Four of these patients were noted to have a raised hemi-diaphragm on chest radiography. Of the two who did not have a raised hemi-diaphragm on chest radiography, one was permanently ventilated. The M mode trace of the paralyzed side showed no active caudal movement of the diaphragm with inspiration and abnormal paradoxical movement (ie cranial movement on inspiration) particularly with the sniff test.

Conclusion:

M mode ultrasonography is a relatively simple and accurate test for diagnosing paralysis of the diaphragm, in the adult population. It can be performed, if necessary, at the bedside and can be easily repeated if paralysis is not thought to be permanent.

Abstract

Objective: The aim of this study was to evaluate the effect of hemiplegia on diaphragmatic movements using motion-mode ultrasonography.

Methods: 23 hemiplegic patients who were diagnosed with a single-hemisphere lesion (mean age 60.5 years; 13 males and 10 females) and a control group of 20 patients (13 males and 7 females) were all evaluated by ultrasonography. Ultrasonography recordings were made of the amplitude of diaphragmatic movement during spontaneous and deep breathing. The patients underwent lung function tests.

Results: When the hemiplegic and control groups were compared, the forced vital capacity, forced expired volume in 1 s, maximum inspiratory pressure and maximum expiratory pressure values were significantly lower in the groups with right and left hemiplegia (p <0.05). When a comparison was made between the right hemiplegic group and the control group and between the left hemiplegic group and the control group in terms of diaphragmatic excursions, for both groups, no significant difference was determined between the movements of the right hemidiaphragm during spontaneous and deep breathing and those of the left hemidiaphragm in spontaneous respiration. In contrast, for both hemiplegic groups, a significant decrease was noted in the movements of the left hemidiaphragm in deep respiration.

Conclusion: The diaphragm is both contralaterally innervated and ipsilaterally innervated, and innervation exhibits marked variations from person to person. This provides an explanation for varying diaphragmatic movements in hemiplegic cases during deep respiration.

Abstract

The diaphragm is the primary muscle of ventilation. Dysfunction of the diaphragm is an underappreciated cause of respiratory difficulties and may be due to a wide variety of entities, including surgery, trauma, tumor, and infection. Diaphragmatic disease usually manifests as elevation at chest radiography. Functional imaging with fluoroscopy (or ultrasonography or magnetic resonance imaging) is a simple and effective method of diagnosing diaphragmatic dysfunction, which can be classified as paralysis, weakness, or eventration. Diaphragmatic paralysis is indicated by absence of orthograde excursion on quiet and deep breathing, with paradoxical motion on sniffing. Diaphragmatic weakness is indicated by reduced or delayed orthograde excursion on deep breathing, with or without paradoxical motion on sniffing. Eventration is congenital thinning of a segment of diaphragmatic muscle and manifests as focal weakness. Treatment of diaphragmatic paralysis depends on the cause of the dysfunction and the severity of the symptoms. Treatment options include plication and phrenic nerve stimulation. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.322115127/-/DC1