Effects of hypertonic mannitol on renal function in open heart surgery.

An extracorporeal bypass was performed in mongrel dogs for 2 hours with or without hypertonic mannitol infusions. In animals given mannitol, the plasma osmolality was elevated maximally to 344 +/- 7.1 mOsm/L and the urine volume was maintained well during bypass. A hypertonic mannitol solution was effective in maintaining the CPAH during and after bypass, but was not effective in minimizing the reduction in Ccr. When the mean arterial pressure during bypass was kept at 60 mmHg, the carbon filling rates in glomeruli showed the favorable effects of mannitol upon renal function, but no effects were observed at a mean arterial pressure of 80 mmHg. In 11 patients who had undergone a bypass lasting more than 2 hrs with mannitol infusions, the plasma osmolality reflected the serum mannitol level and reached 320 +/- 11.0 mOsm/L at 150 min of bypass. The mean urine volume was 5.0 +/- 3.3 ml/min/M2 during the bypass, which was about 7 times as great as before the bypass. The Ccr increased during the first 30 min of the bypass, but it fell to about one half of the initial value after 90 min of the bypass. It was concluded that a hypertonic mannitol solution is effective in maintaining the RPF and urine volume during and after the bypass and that it also preserved the glomerular perfusion even at a low arterial pressure.

Pulsatile venous flow in extracorporeal circulation.

Effects of pulsatile venous flow upon the microcirculation were investigated in conditions with different venous pressures by using regional perfusion in dog's hind legs. In animals with venous pressure of -18 cmH2O (Collapsed stage), venous pulsation brought about a significant increase in mean oxygen consumption ratio and suppressed a rise of mean resistance ratio significantly. In animals with venous pressure of +2 cmH2O (normal venous pressure stage), the venous pulsation was effective in a rise of mean oxygen consumption ratio but was not effective in suppression of mean resistance ratio. In animals with venous pressure of +10 cmH2O (congestive stage), no effect of venous pulsation was recognized. We suppose that the intermittent elevation of venous pressure by venous pulsation is effective for opening some capillaries in animals with venous pressure below +2 cmH2O.

Surveillance and follow-up of patients with implanted cardiac pacemaker by telephone transmission.

A follow-up study on pacemaker function in 15 patients with implanted cardiac pacemaker has been performed by telephone transmission. The transmitting set consisting of electrocardiograph, pacemaker pulse modulator and acoustic coupler was manipulated by the patients themselves. ECG, pacemaker pulse, and pulse rate were simultaneously transmitted through 1 channel to the receiver in our clinic. Of 56 patients with pacemaker, 15 patients were surveyed by telephone transmission. In these patients battery exhaustion was detected in 3, competition in 2, and lead fracture in 1. The fact that surveillance and follow-up of the patients with implanted cardiac pacemaker could be carried out by telephone transmission as well as by clinic visitation tells us that the telephone transmission is a useful method and plays an important role in a pacemaker clinic. Moreover our study established its further usefulness in the patient's preference due to difficulties in travelling to the pacemaker clinic and in reducing patient's anxiety.

[Surgical management of acquired tricuspid insufficiency--valvular replacement or annuloplasty? (author's transl)]. / Zur chirurgischen Behandlung der erworbenen Trikuspidalklappeninsuffizienz--Klappenersatz oder Anuloraphie

61 patient underwent operative repair of acquired tricuspid insufficiency (T.I.) during correction of multiple valvular disease. 45% presented a relative T.I. through annular dilatation, while organic lesions of the tricuspid valve were found in 56% of the patients. A tricuspid valvular replacement was carried out in 17, and a tricuspid annuloplasty in 44 patients. We believe that during surgical management of multiple valvular lesions, all tricuspid insufficiencies of even when only of a slight to moderate degree - should be corrected aggressively. Tricuspid valvular replacement should be avoided if possible and a tricuspid annuloplasty should be performed.