Biomedical subjects

E Deegen

Publications and source records attributed to E Deegen.

94 records · Page 6Linked to original sources

PubMedDate not supplied

Differences in quantitated electroencephalographic variables during surgical stimulation of horses anesthetized with isoflurane.

The effects of noxious surgical stimulation on the electroencephalogram (EEG) in 15 horses anesthetized with isoflurane were evaluated during orthopedic (group 1) and soft tissue (group 2) procedures. The quantitative EEG variables theta/delta ratio (T/D), alpha/delta ratio (A/D), beta/delta ratio (B/D), median power frequency (MED), and 80% spectral edge frequency (SEF 80) recorded during Surgeries at 1.7% end-tidal concentration of isoflurane (ET(iso)) were compared with values from five nonstimulated control horses anesthetized at 1,7% ET(iso). The EEG variables T/D, A/D, MED, and SEF 80 from surgically stimulated horses were significantly higher compared with controls. These differences in measured EEG variables were accompanied by a significantly lower relative power in the delta frequency band and a concomitant significantly higher alpha activity. Because the A/D ratio, MED, and SEF 80 in surgically stimulated horses were significantly higher than in nonstimulated control horses these measured EEG variables may provide a valuable tool for identification of nociceptive transmission in isoflurane anesthetized horses.

Anesthetics, Inhalation↗

PubMedDate not supplied

Evaluation of magnetic resonance imaging techniques in the equine digit.

An anatomic study of the equine digit using magnetic resonance imaging (MRI) was performed. Seventeen isolated forelimbs and one hindleg of nine warmblood horses were imaged in transverse, sagittal, and dorsal planes with a 1.5 Tesla magnet using T1-, T2- proton density-weighted spin echo sequences as well as T2 gradient echo sequences. One scan plane in each horse was compared with corresponding anatomic and histologic sections. The best imaging planes to visualize various anatomic structures were determined. Fibrocartilage was visualized in the insertion of the deep digital flexor tendon and the suspensory ligament as well as in the distal sesamoidean ligaments. The correlation of MRI images with anatomic and histologic sections confirmed that all of the anatomic structures in the equine digit could be evaluated in PD and T2 studies.

Animals↗

PubMedDate not supplied

Percutaneous lung biopsy in the horse: comparison of two instruments and repeated biopsy in horses with induced acute interstitial pneumopathy.

The aim of the study reported here was to compare complications of lung biopsy in horses and the quality of the lung specimens after biopsy using the manual Tru-Cut biopsy needle (TC) and an automated biopsy needle (ABN). For experiment 1, lung biopsy was performed in 50 horses with one instrument on one side of the thorax, and then with the other instrument on the other side. Postmortem examination was performed in 20 of the 50 horses. Coughing was detected in 10 of 50 horses and epistaxis was observed in 6 of the 50 horses. Endoscopy revealed bleeding into the airways in 16 of 49 horses and in 5 of 49 horses after biopsy with the TC or the ABN, respectively. Use of the ABN induced a significantly smaller amount of bleeding. Pneumothorax was detected by radiography in 1 of 50 horses. Hematoma diameter determined in 7 of 20 horses at postmortem examination, was significantly larger after biopsy with the TC than with the ABN. The quality of the lung specimen was good. In experiment 2, complications after repeated and multiple lung biopsies in 6 horses were evaluated. Moderate epistaxis was observed on 13 of 104 occasions. Bleeding into the airways was detected at endoscopy on 41 of 104 occasions, and pneumothorax was detected during 4 of 104 occasions. Complications such as hematoma at the biopsy site and bleeding into the airways were greater after biopsy with the TC than after use of the ABN. Lung biopsy specimens obtained with the ABN were fairly safe for the animal.

Animals↗

PubMedDate not supplied

[Pulsed Doppler echocardiography measurement in healthy warmblood horses].

Twenty adult warm blooded horses (body weight 585 +/- 59 kg) were evaluated with pulsed doppler echocardiography. Locations for the transducer and the sample volume were determined to get typical blood flow tracings of the equine heart. Angle of doppler beam was between 37 degrees and 40 degrees in right heart atrioventricular flow tract and between 44 degrees and 47 degrees in left heart atrioventricular flow tract. Peak blood flow velocity (angle corrected) was 0.71 +/- 0.17 m/s in tricuspid valve and 0.92 +/- 0.22 in mitral valve. In right and left atrioventricular flow tracts in all sample volume positions typical double peaked spectral tracings of blood flow were seen. In supravalvular, valvular and subvalvular sample volume locations of the ventriculoatrial flow tracts angles were between 28 degrees and 33 degrees in right heart and between 34 degrees and 37 degrees in left heart. Peak flow velocity (angle corrected) was 0.98 +/- 0.13 m/s in pulmonary valve and 0.92 +/- 0.09 m/s in aortic valve. Paradoxical systolic and diastolic flows were seen. The flow velocity tracings were similar to those found in man. Flow velocity values of clinically normal horses have a wide range like in healthy human beings. Nevertheless flow tracings of healthy horses have a characteristical profile and may be helpful in detecting abnormal blood flow in heart diseased horses.

Animals↗