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Biomedical subjects

T Weinberger

Publications and source records attributed to T Weinberger.

10 recordsLinked to original sources

Comparison of sodium bicarbonate, Carbicarb, and THAM during cardiopulmonary resuscitation in dogs.

OBJECTIVES: During cardiopulmonary resuscitation (CPR), elimination of CO2 was shown to be limited by low tissue perfusion, especially when very low perfusion pressures were generated. It has therefore been suggested that sodium bicarbonate (NaHCO3), by producing CO2, might aggravate the hypercarbic component of the existing acidosis and thereby worsen CPR outcome. The objectives of this study were to evaluate the effects of CO2 producing and non-CO2 producing buffers in a canine model of prolonged ventricular fibrillation followed by effective CPR. DESIGN: Prospective, randomized, controlled, blinded trial. SETTING: Experimental animal research laboratory in a university research center. SUBJECTS: Thirty-eight adult dogs, weighing 20 to 35 kg. INTERVENTIONS: Animals were prepared for study with thiopental followed by halothane, diazepam, and pancuronium. Ventricular fibrillation was electrically induced, and after 10 mins, CPR was initiated, including ventilation with an FIO2 of 1.0, manual chest compressions, administration of epinephrine (0.1 mg/kg every 5 mins), and defibrillation. A dose of buffer, equivalent to 1 mmol/kg of NaHCO3, was administered every 10 mins from start of CPR. Animals were randomized to receive either NaHCO3, Carbicarb, THAM, or 0.9% sodium chloride (NaCl). CPR was continued for up to 40 mins or until return of spontaneous circulation. MEASUREMENTS AND MAIN RESULTS: Buffer-treated animals had a higher resuscitability rate compared with NaCl controls. Spontaneous circulation returned earlier and at a significantly higher rate after NaHCO3 (in seven of nine dogs), and after Carbicarb (six of ten dogs) compared with NaCl controls (two of ten dogs). Spontaneous circulation was achieved twice as fast after NaHCO3 compared with NaCl (14.6 vs. 28 mins, respectively). Hydrogen ion (H+) concentration and base excess, obtained 2 mins after the first buffer dose, were the best predictors of resuscitability. Arterial and mixed venous Pco2 did not increase after NaHCO3 or Carbicarb compared with NaCl. CONCLUSIONS: Buffer therapy promotes successful resuscitation after prolonged cardiac arrest, regardless of coronary perfusion pressure. NaHCO3, and to a lesser degree, Carbicarb, are beneficial in promoting early return of spontaneous circulation. When epinephrine is used to promote tissue perfusion, there is no evidence for hypercarbic venous acidosis associated with the use of these CO2 generating buffers.

Animals

Telemedicine in primary care in Israel.

A primary-care teleconsulting system was established between an academic family medicine centre and a clinic about 50 km away. The videoconferencing units were connected at 384 kbit/s. Seven patients were examined by a physician in the clinic and then examined by a consulting physician using the telemedicine system. Four other patients were examined through the telemedicine system first and by a local physician later. The telemedicine consultation solved five of the patients' medical problems. The waiting period before receiving expert medical consultation was reduced. There was full patient satisfaction regarding this method of consultation, patient 'run around' was avoided and patients felt at ease. The telemedicine consultation process improved the patient-physician bond and the attending physician's level of confidence.

Adult

[B-mode, M-mode and Doppler sonographic findings in mitral valve insufficiency of horses].

B- and M-mode echocardiography was performed on 38 horses. 34 patients had systolic heart murmur with the point of maximal intensity over mitral valve. Additionally, 17 of these patients were examined with the pulsed wave doppler echocardiography (Vingmed 200). In 26 patients with cardiac murmur and in 4 patients without cardiac murmur a mitral valve insufficiency was diagnosed by echocardiography. In 8 horses with a systolic murmur over mitral valve M- and B-mode evaluation could not reveal a haemodynamic importance of the murmur. The diagnosis of MVI was based on a dilation of left atrium with or without additional dilation of left ventricle on one hand and with a regurgitation of blood into left atrium found by pulsed wave doppler on the other hand. In 6 extremely dilated hearts a "real" ostium of regurgitation was detected as a direct echocardiographic finding in B-mode. Good correlations existed between echocardiographically evaluated changes of heart dimensions and autopsy measurements in 10 cases. The prognosis seems to be poor if systolic murmurs coincide with dilatation of left atrium and left ventricle, regurgitation of blood into left atrium or with a high degree dilation of left atrium without changes of left ventricle chamber size. In hearts with little to medium dilated left atrium without changes of left ventricle dimension and additionally a regurgitation into left atrium the prognosis seems at least to be cautious. Echocardiography is an available diagnostic help in evaluation of the importance of systolic murmur with the point of maximal intensity over the mitral valve especially in completion by pulsed wave doppler.

Animals

[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