イヌにおける実験的急性肺水腫の作製と,その肺血行動態の研究,とくに,肺循環系圧勾配の逆転に関連して

type:text

(1) Fourteen adult mongrel dogs weighing 9 to 20kg were anesthetized with pentobarbital sodium (25mg/kg). Epinephrine (0.25, 0.5, 0.75 or 1.0mg/kg) plus 2.5 l of physiological saline solution (38℃) was infused into the femoral vein at rates from 1.5 to 5.9m//kg/min to produce acute pulmonary edema. Regardless of the dose of epinephrine applied, 4/7 of the total dose of epinephrine was always mixed with the first 1 / of normal saline solution while 3/7 was mixed with the remaining 1.5 / of the solution. (2) Acute severe pulmonary edema of the lungs/body weight index 2.00 to 4.58 was produced in eight dogs by an infusion of 4 to 5ml kg/min. of normal saline solution plus epinephrine (0.5 to 0.75 mg/kg). (3) In the control group, a mean value and a standard deviation for the mean pulmonary arterial pressure (PAm) was 14.6±3.3 mmHg, for the mean pulmonary venous pressure (PVm), 5.8±3.0 mmHg, for the mean left atrial puressure (LAm), 4.3±2.5 mmHg and for the mean femoral arterial pressure (FAm), 120.4±19.2 mmHg. (4) PAm, PVm, LAm and FAm at the time of 0.5, 1.0, 1.5, 2.0 and 2.5/ of infusion were recorded in the following two groups ; the severe group comprising eight dogs with pulmonary edema in which the lungs/body weight index was greater than or equal to 2.0 and the mild group, five dogs with pulmonary edema of which the lungs/body weight index was less than 2.0. Acute pulmonary edema began to develop at the time of 0.5l of infusion when the mean pressures in the two groups were, PAm severe group, range: 38〜60mmHg mean ± S.D.: 49.3±7.2mmHg range: 30〜49mmHg mean ± S.D.: 39.5±8.3mmHg range: 36〜58mmHg mean ± S.D.: 46.2±7.2mmHg range: 23〜45mmHg mean ± S.D.: 29.2±8.1mmHg range: 30〜62mmHg mean ± S.D.: 45.5±10.8mmHg range: 10.5〜36mmHg mean ± S.D.: 24.1±8.2mmHg range : 130〜286mmHg mean ± S.D.: 207.9±47.0mmHg range: 171〜223mmHg mean ± S.D.: 191.2±20.0mmHg Significant difference in PVm and LAm was noted between the two groups at infusion of 0.5, 1.0, 1.5 and 2.0l.

(5) The pressure gradient between pulmonary artery and left atrium (PAm-LAm) was decreased and reversed in many dogs in the severe group like the other pressure gradients in the pulmonary circulation. The pressure gradients in the pulmonary circulation were increased in the mild group. These tendencies were continued up to 2.0l of the infusion in both groups. The (PAm-LAm) pressure gradient in the two groups at the time of 0.5 and 2.0l of infusion was, range: -4〜12.4mmHg mean ± S.D.: 3.7±6.7mmHg range : 3.0〜27.7 mmHg mean ± S.D.: 15.4±9.2mmHg range: -5〜2.7mmHg mean ± S.D.: -1.8±3.0mmHg range: 2〜19mmHg mean ± S.D.: 9.4±6.2mmHg Therefore, the noticeable hemodynamic abnormalities in the acute severe pulmonary edema in dogs were unusual elevation of the pressures in the pulmonary circulation and mild group. PVm severe group. mild group. LAm severe group. mild group. FAm severe group. mild group. (PAm-LAm) severe group, at 0.5l mild group. (PAm-LAm) severe group, at 2.0l mild group. decrease and reversal of the (PAm-LAm) pressure gradient. (6) The coefficient of correlation between the lungs/body weight index and the mean pressures in the pulmonary circulation was+0.76 for LAm (p<0.005), +0.75 for PVm (p<0.005), and +0.60 for PAm (p<0.05). The coefficient of correlation between the lungs/body weight index and the (PAm-LAm) pressure gradient was -0.77 at 0.5l of infusion, -0.59 at 1.0l, -0.67 at 1.5l and -0.70 at 2.0l. Thus, the lungs/body weight index showed a good correlation with the (PAm-LAm) pressure gradient. (7) The bloody sputa were excreted from the airway of seven dogs in the severe group. Both lungs/body weight index and lungs/heart weight index could indicate severity of the acute pulmonary edma in dogs equally well. (8) Ligation of the bronchial arterial system performed as completely as possible could not alleviate the severity of acute pulmonary edema in the dog. (9) Marked edema was found in the perivascular and peribronchial interstitial tissues of the lung.