Unilateral diaphragmatic paralysis: inspiratory muscles, breathlessness and exercise capacity

Background

Patients with unilateral diaphragmatic paralysis (UDP) may present with dyspnoea without specific cause and limited ability to exercise. We aimed to investigate the diaphragm contraction mechanisms and nondiaphragmatic inspiratory muscle activation during exercise in patients with UDP, compared with healthy individuals.

Methods

Pulmonary function, as well as volitional and nonvolitional inspiratory muscle strength were evaluated in 35 patients and in 20 healthy subjects. Respiratory pressures and electromyography of scalene and sternocleidomastoid muscles were continuously recorded during incremental maximal cardiopulmonary exercise testing until symptom limitation. Dyspnoea was assessed at rest, every 2 min during exercise and at the end of exercise with a modified Borg scale.

Main results

Inspiratory muscle strength measurements were significantly lower for patients in comparison to controls (all p<0.05). Patients achieved lower peak of exercise (lower oxygen consumption) compared to controls, with both gastric (−9.8±4.6 cmH₂O versus 8.9±6.0 cmH₂O) and transdiaphragmatic (6.5±5.5 cmH₂O versus 26.9±10.9 cmH₂O) pressures significantly lower, along with larger activation of both scalene (40±22% EMGmax versus 18±14% EMGmax) and sternocleidomastoid (34±22% EMGmax versus 14±8% EMGmax). In addition, the paralysis group presented significant differences in breathing pattern during exercise (lower tidal volume and higher respiratory rate) with more dyspnoea symptoms compared to the control group.

Conclusion

The paralysis group presented with exercise limitation accompanied by impairment in transdiaphragmatic pressure generation and larger accessory inspiratory muscles activation compared to controls, thereby contributing to a neuromechanical dissociation and increased dyspnoea perception.

The exercise capacity limitation in patients with unilateral diaphragmatic paralysis is characterised by an inefficient hemidiaphragm contraction. Consequently, there is a neuromechanical dissociation with an overload of inspiratory accessory muscles and higher breathlessness.https://bit.ly/2XxAR4K

Epipericardial fat necrosis: an underdiagnosed condition

OBJECTIVE

Epipericardial fat necrosis (EFN) is an uncommon benign and self-limited condition that leads patients to the emergency department (ED) owing to the onset of acute pleuritic chest pain. The aim of this study was to describe the cases of this disease in our institution and to illustrate the associated clinical and radiological findings.

METHODS

We reviewed 3604 chest scans referred by the ED from November 2011 to July 2013. Patients diagnosed with epipericardial necrosis had their medical records and original tomography reports analysed.

RESULTS

Chest pain was the primary complaint in 426 patients; 11 of them had definitive EFN findings characterized by a round soft-tissue attenuation lesion with a varying degree of strands. All patients presented with pleuritic chest pain on the same side as the lesion. Pericardial thickening, pleural effusion and mild atelectasis were the associated tomography findings. Cardiac enzyme and D-dimer tests performed during the episode were normal in all cases. 27% of the cases only were correctly diagnosed with EFN at the time of presentation.

CONCLUSION

EFN is a benign inflammatory condition frequently overlooked in the ED by physicians and radiologists but is an important factor in the differential diagnosis of patients with acute chest pain.

ADVANCES IN KNOWLEDGE

The article adds clinically and radiologically useful information about the condition and displays the importance of making the correct diagnosis to avoid unnecessary examinations.

Listeria monocytogenes peritonitis in cirrhotic patients: first description in Brazil

Two cases of spontaneous bacterial peritonitis (SBP) caused by Listeria monocytogenes in cirrhotic patients are reported. In one of the cases, the microorganism was isolated from pleural effusion and ascites. SBP is a serious and common complication of patients with ascites caused by hepatic cirrhosis and the culture of the ascitic fluid is an important tool for the diagnosis and for the more appropriate treatment. Although a third generation cephalosporin has usually been employed for empiric treatment of SBP, it does not provide adequate coverage against Listeria spp. In such cases the use of ampicillin (with or without sulbactam) or sulfamethoxazole-trimethoprim is recommended. The last one is used for secondary prophylaxis, instead of norfloxacin. To summarize, Listeria monocytogenes infection is a rare cause of SBP, whose treatment should be specific for the bacteria.