[Effect of forced respiration on the stress on puncture channels of sutures in transverse laparotomies of the upper abdomen; experimental studies in the anesthesized dog].

In 11 mongrel dogs in propiophenylpromazine-pentobarbital-anaesthesia the influence of forced respiration on the load of puncture channels of a suture was investigated. For this horizontal suture in the upper abdominal wall, threads No. 3 USP and round needles No. ECT-4 were used. The experiments were carried out in supine position with stretched hindlegs, in supine position with relaxed hindlegs, in lateral position, and in hanging abdominal position. Measurements were performed with a selfconstructed resistance strain gauge element. Rising forced respiration pressure increased the inspiratory load of puncture channels, but there were no significant differences between spontaneous breathing and forced respiration with pressure of 10 cm H2O. In contrary to this there were highly significant differences between spontaneous breathing and forced respiration with pressure of 20 and 30 cm H2O (multiple variance analysis). For instance the load during forced respiration with a pressure of 30 cm H2O in supine position with relaxed hindlegs rose about 67% above pressure values of spontaneous breathing. It could be shown that the expiratory load in the puncture channels was not influenced by forced respiration pressure, but depended on the body position; in dogs it was minimal in side position (45-48 g), higher in supine position with relaxed hindlegs (67-71 g), even higher in supine position with stretched hindlegs (88-92 g), and maximal in hanging abdominal position (109-113 g). By this investigation the increase of load in the puncture channels during forced respiration with pressures of 20 and 30 cm H2O was quantified.