Cardiovascular responses to clamping of the aorta during epidural and general anesthesia.

The cardiovascular responses of aortic cross-clamping and declamping with normal and high ventricular filling pressures were compared during epidural and nitrous oxide-morphine anesthesia in 32 male patients undergoing reconstructive aortic surgery. The patients were divided into four groups. Groups I and II had lumbar epidural blocks with bupivacaine and received nitrous oxide in oxygen to breathe; groups III and IV were anesthetized with morphine (2 mg/kg) and nitrous oxide.

A guideline for anticipated blood usage during elective surgical procedures.

A realistic guideline for transfusion therapy was prepared, with the cooperation of the departments of anesthesiology and surgery, in order to reduce excessive crossmatching. The guideline recommends an ABO-Rh type and an antibody screen, instead of the ""routine'' two-unit crossmatch, for elective surgical procedures where blood is seldom used. For those operations normally necessitating hemotherapy, the number of units suggested for the preoperative crossmatch was determined by examination of the average number of units transfused in the past for that particular procedure.

Acute respiratory failure and intravascular coagulation.

The possible association between acute respiratory failure and disseminated intravascular coagulation was examined in eight patients with severe acute respiratory failure--a condition characterized by tachypnea, right to left intrapulmonary shunting of blood greater than 30 per cent of cardiac output, increased pulmonary artery pressure with low or normal pulmonary artery wedge pressure and roentgenologic interstitial pulmonary edema. Treatment consisted of mechanical ventilation with positive end expiratory pressure sufficient to minimize intrapulmonary shunting. There was no abnormality in platelet concentration fibrin split product concentration, fibrinogen concentration, prothrombin time or activated partial thromboplastin time during the period of most severe respiratory failure in any patient.

Change in pulmonary venous admixture with varying inspired oxygen.

Pulmonary venous admixture (Qsp/Qt) was analyzed as a function of fractional concentration of inspired O2 (FIO2) in 30 patients who required postoperative mechanical ventilation. Pulmonary and radial artery blood-gas tensions and pH were measured and Qsp/Qt was calculated with FIO2 ranging from 0.21 to 1.