Kunio Suwa

The Effects of Stellate Ganglion Block on the Idiopathic Prolongation of the Q-T Interval with Cardiac Arrhythmia (The Romano-Ward Syndrome)

The association of a prolonged Q-T interval, congenital deafness, and syncopal attacks due to ventricular fibrillation following emotional or physical stress is known as the Jervell-Lange-Nielsen syndrome. Absence of the congenital deafness characterizes the otherwise identical Romano-Ward syndrome. Both conditions have a high mortality rate and are recognized as contributing to sudden death in children. Although the pathogenetic factors are not yet completely elucidated, the condition is well enough understood to permit effective treatment. The authors performed a left stellate ganglion block in a 12-year-old girl with a mild form of the Romano-Ward syndrome, shortening the Q-T interval and eliminating the ventricular tachyarrhythmia. The left stellate ganglion block should be considered by anesthesiologists as an emergency measure, effective in interrupting the attack.

Beneficial effects of the prone position on the incidence of barotrauma in oleic acid‐induced lung injury under continuous positive pressure ventilation

Background: Factors that contribute to ventilator‐induced barotrauma are not well defined. This study investigates the effects of posture on ventilator‐induced barotrauma, as well as arterial oxygenation.

The effect of gas inflow on the regulation of CO2 levels with hyperventilation during anesthesia.

The authors describe a method by which a normal CO2 level may be achieved during hyperventilation, simultaneously regulating fresh gas flow rate (V l/min, ambient temperature) into an anesthesia circle system from which the carbon dioxide absorber has been removed. Using a tidal volume of 15 ml/kg and a respiratory rate of 16/min, PAco2 may be approximated as where Vco2 is calculated according to the formulas of Kleiber. In 35 patients studied, the PAco2 values observed agreed well with the calculated values when the latter were above 30 torr. With increases in V, observed values generally exceeded calculated values, indicating increasing fresh gas flow bypassing the patient.

Normal Hemoglobin–Oxygen Affinity

Hemoglobin-xoygen affinity is known to vary in a number of disease states. The authors measured the continuous affinity of blood from healthy subjects and, using mathematical data reduction techniques, calculated coefficients for rational function models of average normal affinity, plus or minus 2 standard deviations, and 95 per cent confidence limits. Average normal P50 was 27.10 torr, with a two-standard-deviation range of 25.85 to 28.35; P50s of the 95 per cent confidence limits were 26.69 and 27.53 torr. The affinity usually accepted as standard lay between or very near to the 95% confidence limits of normal throughout its range. It is concluded that the range of normal affinity is narrow and that, for most practical purposes, standard affinity adequately represents normal affinity. There should be little difficulty in distinguishing from normal the shifts that occur in certain disease conditions.

Vagal and sympathetic denervation in the development of oleic acid-induced pulmonary edema

This study investigates the effects of autonomic denervation on extravascular lung water, pulmonary hemodynamics, the filtration coefficient of pulmonary vasculature and oxygenation in the development of pulmonary edema. Thirty seven dogs were divided into seven groups. No experimental treatment was conducted in group Nc (n = 4, sham operation) or group Nv (n = 6, bilateral vagotomy) during a 3 h observation period. In the following groups, oleic acid (0.06 ml/kg) was injected into a central vein to induce pulmonary edema: group OAc (n = 6, intact innervation); group OAv (n = 6, bilateral vagotomy); group OAa (n = 6, alpha-blockade by phentolamine); group OAs (n = 6, alpha- and beta-blockade by sympathectomy); and group OAvs (n = 3, vagosympathectomy). The results showed that in the dogs with normal lungs, bilateral vagotomy per se did not cause lung injury during 3 h of observation. However, in oleic acid pulmonary edema, vagotomy significantly deteriorated pulmonary edema by increasing pulmonary intravascular pressures; Alpha- or alpha- and beta- sympathetic inhibition deteriorated pulmonary edema by increasing pulmonary microvascular permeability. The severity of oleic acid-induced pulmonary edema was same in the dogs with vagosympathectomy as in the dogs with intact innervation. These results suggest the inhibition of vagal or sympathetic innervation will aggravate pulmonary edema in the dog.

Pulmonary capillary pressure measured with a pulmonary arterial double port catheter in surgical patients.

We developed a pulmonary artery (PA) double port catheter technique for reliable clinical measurements of pulmonary capillary pressure (Ppc). In seven elective surgical patients, the PA double port catheter with the second PA port 1 cm proximal to the balloon was inserted. The two PA ports, connected to identical pressure measuring systems, provided the pulmonary arterial pressures (Ppa) distal and proximal to the balloon. After general anesthesia was stabilized, the two Ppas were measured simultaneously during a PA occlusion maneuver during 10 s of apnea. The instant of occlusion was determined precisely as the time when the two Ppa traces sharply diverged. A single exponential equation was fitted to the segment of distal Ppa tracing starting 0.3 s after the instant of occlusion. Ppc was determined as the value of the exponential fit extrapolated to time 0. In six of seven patients, PA occlusion occurred consistently in the early systolic phase regardless of the timing of balloon inflation. Mean Ppa, Ppc, and pulmonary arterial wedge pressure were 16.6, 11.8, and 7.6 torr. The ratio of venous to total resistance ranged from 0.37 to 0.54 (mean:0.46). We conclude that this technique is clinically feasible and valuable in precise definition of the instant of PA occlusion. By defining PA occlusion consistently, this technique can provide reliable Ppc estimation in the clinical settings.

Analysis of oxygen transport and oxygen utilization combined

We propose a model which combines oxygen transport system from blood to tissue with oxygen utilization system at the tissue. The model consists of 3 equations; the relationship between tissue PO2 (PtsO2) and O2 utilization (VrcO2), diffusion from vessel to tissue, and Fick equation. This model has two advantages. First, it is self-consistent. Varying VrcO2 varies the oxygen transport. Second, it enables to analyze the effects of various factors of oxygen transport/utilization on other factors.We applied this model to the brain tissue. Following values were assumed. Critical tissue PO2 (PcritO2) 2 mmHg; oxygen utilization above this level 3 ml·min−1·100g−1; diffusion coefficient from blood vessel to tissue (D) 0.2 ml·min−1·mmHg−1·100g−1 cerebral blood flow (CBF) 50 ml·min−1·100g−1; hemoglobin 15 g·100ml−1. Hill equation was used for oxygen dissociation curve with n of 2.7 and P50 of 27.0 mmHg.From these, the following values were obtained; PvO2, PtsO2 and VrcO2. The changes were analyzed for the 5 input values, PaO2, CBF, D, P50 and Hb, changing from zero to their respective normal values. A reduction of a single parameter down to 50% of normal barely affected oxygen utilization. A further reduction resulted in significant oxygen utilization. Under conditions studied, a decrease in P50 reduced oxygen utilization faster than that in any other parameters.

Analysis of oxygen transport to the brain when two or more parameters are affected simultaneously

AbstractWe composed a model, combining oxygen transport system from blood to tissue with the oxygen consumption system at the tissue. The aim of this study is to apply it to the brain tissue under conditions when two or more oxygen transport parameters are affected simultaneously. The following values were assumed. Critical tissue

Hemodynamics and oxygen consumption during warm heart surgery

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