Basic principles of electrohaemodynamics.

Electrohaemodynamics (EHD) is a method of measuring cardiac output continuously, also cardiac index, stroke volume, blood flow through limbs, vascular resistance, useful work output from the heart, elastic properties of arterial walls, and contractile and rate of energy generation properties of heart muscle. The method is based on simultaneous measurements of the time variations of arterial blood pressure and electrical conductance in a portion of human body. The measurements, in the form of analogue signals, are processed by means of a microprocessor or a mini-computer. The processing is based on equations which combine haemodynamics with measurements of electrical conductance and arterial pressure variation. Direct comparison of simultaneous cardiac output measurements using EHD and thermal dilution, as well as indirect comparisons with the Fick and dye dilution methods, show that EHD is at least as accurate as these methods. The reproducibility of EHD is within one percent when the subjects are in the steady state, which appears to be better than any other known technique.

Experimental study of the relationship between the base impedance and its time derivative in impedance plethysmography.

Transthoracic electrical impedance Z consists of a constant baseline component Z0 and the time variable component delta Z such that Z = Z0 + delta Z. The first time derivative of Z has a negative peak, the magnitude of which is (dZ/dt)min. Measurements of 170 volunteers show that (dZ/dt)min is a function of the constant baseline component Z0. This implies that at least a part of the difference of the magnitudes of (dZ/dt)min on Z0 must be taken into account in order to avoid erroneous conclusions or inaccurate calculations.

Poloxamer 188 as vehicle for injectable diazepam.

The significant occurrence of thrombophlebitis in patients administered diazepam intravenously was described recently. This side effect has been attributed to the crystallization of diazepam and its subsequent precipitation upon contact with blood or intravenous fluids. The current study was designed to reveal whether the solubilizing capability of poloxamer 188 reduces the incidence of thrombotic and inflammatory effects of diazepam in rabbits. The incidence of early (3-hr) ear vein necrosis was 72% in the diazepam-treated ears, while the incidence of necrosis in the ears that received poloxamer 188 as a vehicle for diazepam was 25%. The occurrence of thrombosis and loss of vessel integrity also was higher in diazepam-treated ears than in those treated with diazepam plus poloxamer 188. Solubilization of diazepam with poloxamer 188 may decrease the incidence of the tested side effects.

Diazepam-ketamine anaesthesia for open heart surgery a "micro-mini" drip administration technique.

Two hundred open-heart cases were anaesthetized with a diazepam-ketamine combination. The results were excellent. A "Micro-Mini" drip technique insured low, even, but adequate dose levels of ketamine and less drug was used. Induction and maintenance are simple and smooth. Effects on the cardiovascular system and respiratory system are minimal. The margin of safety is wide and 100% oxygen can be used whenever needed.

Diazepam-ketamine anaesthesia for open heart surgery "micro-mini" drip administration technique.

Two hundred open heart cases anaesthetized with a combination of diazepam-ketamine using "Micro-Mini" drip administration technique were presented. The results were eminently desirable, and in the opinion of the authors are a notable improvement over other methods for all types of cardiovascular surgery including most advanced heart diseases. The advantages of this anaesthetic method for cardiovascular surgery are as follows: 1. Effects on cardiovascular system are minimal.--2. Respiratory depression is negligible.--3. There is no increase in salivation or muscle tone.--4. Induction and maintenance of anaesthesia are simple and smooth.--5. Anaesthesia can be maintained, using a high concentration of oxygen alone, by a slight increase in rate of ketamine administration whenever necessary.--6. Post-anaesthetic psychotomimetic effects are negligible.--7. Nearly 100% of patients have excellent amnesia.--8. It has a wide margin of safety.--9. This technique has proved highly acceptable to patients and surgeons. We feel ketamine should be used in small dosages continuously administered with either "Micro-Mini" drip infusion or infusion pump. Ketamine given in this fashion should be regarded as an analgesic.

Ryodoraku therapy for migraine headache.

The authors discuss Ryodoraku electric acupuncture therapy in detail in Part I. The results of the treatment of migraine headache (20 cases) by Ryodoraku therapy were investigated in part II. In the present study 15 out of 20 patients achieved good to excellent responses to this type of therapy.