[Changes in ventilation during use of heat and humidity exchangers]. / Variazioni della ventilazione dovute all'uso di scambiatori di umidità e calore.

The Authors studied in 10 patients during mechanical ventilation the effects of the application of heat and moisture exchanger (HME) in the presence of constant TV and frequency. They observed an increase of PaCO2 and PE, CO2 during the use of HME; this is due to Vd/Vt increase. The Authors conclude that it is mandatory to increase the total ventilation when using HME to avoid dangerous levels of hypercapnia.

Low-dose heparin in thoracic surgery: effect on blood coagulation and fibrinolysis system.

Plasma kallikrein, antithrombin III and antiplasmin were determined with chromogenic methods in 29 patients pre-, per- and post-operatively in a controlled, randomized study. 16 patients received calcium heparin, 5000 IU s. c. every 8 hr for 7 days, the first administration given 2 hr before surgical procedure. 13 control patients received saline. A significant reduction of kallikrein and antiplasmin in per- and post-operative periods was observed in the control patients compared with the heparin-treated patients, while there was a significant reduction of anti-thrombin III in the control patients compared with the treated patients only in the per-operative period. The results obtained suggest that activation of the coagulation and fibrinolysis system occurs in patients undergoing thoracic surgery, and that it is inhibited significantly by calcium heparin prophylaxis.