This clinical experience demonstrates that young, otherwise healthy people can survive accidental deep hypothermia with no or minimal cerebral impairment, even with prolonged circulatory arrest. Cardiopulmonary bypass appears to be an efficacious rewarming technique.

Sixteen patients (age 13-53 years) with accidental deep hypothermia have been rewarmed in our clinic during the last 10 years, 14 by femoro-femoral cardiopulmonary bypass (CPB) of whom 11 had a cardiopulmonary arrest (asystole in 5 and ventricular fibrillation in 6). On admission, the latter were clinically dead showing wide non-reactive pupils and being supported by ventilation and external heart massage. In the survivors, the mean length of cold exposure was 4.4 h (2-5.5 h) and mean arrest interval until initiation of CPB was 2.5 h (1.4-3.7 h). Rectal temperature on admission ranged from 17.5 degrees C to 26 degrees C (mean 22.5 degrees C). The causes for hypothermia were fall into a crevasse (5), avalanche (1), drowning (2) and cold exposure (3) including 2 suicide attempts. Results are summarized in the following table: [table: see text] Eight of the 11 patients with deep hypothermia and cardiac arrest were rewarmed and resuscitated successfully with CPB. Three patients, including 2 cases of asphyxia (avalanche and drowning), could not be weaned from CPB despite adequate rewarming. The other drowned patient (53 years) died on the 3rd postoperative day (POD) from ARDS. The main complication was pulmonary edema (57%) and transient neurological deficits. All survivors became conscious during the first POD and resumed, their professional activity. We conclude that patients with accidental deep hypothermia and even prolonged cardiopulmonary arrest should be rewarmed and resuscitated rapidly by cardiopulmonary bypass. These measures are very promising particularly if the cause of accident and the circumstances suggest that cardiopulmonary arrest was induced by hypothermia alone without other asphyxiating mechanisms.

Objects. Myocardial revascularization is performed preferentially with internal mammary artery grafts. Pedicle preparation and pharmacologic vasodilatory treatment vary greatly. Objective measurements are difficult since peripheral and later coronary vascular resistance and possible competitive flow of the native bypassed coronary artery will influence the results significantly. Our objectives were:(1) measurement of internal mammary artery graft flow with the transit-time flow technique; (2) comparison of two surgical take-down techniques (skeletonizing vs standard pedicle preparation): (3) quantitation of transit-time flow compared to the free pedicle flow and (4) the vasodilatory effect of papaverine on internal mammary artery flow.Method. Consecutive elective cases of coronary artery bypass grafting, performed by two surgeons using routinely either skeletonizing of the internal mammary artery (group A, n = 10) or classtcal pedicle preparation technique (group B, n = 10), were studied prospectively. Anesthesia, cardiopulmonary bypass and operative data were otherwise comparable; likewise, hemodynamlc parameters showed no statistical differences between the two groups. Transit-time flow (CardioMed, MediStim, Norway) was measured at the following time points: beginning (1) and end of take-down (2); after papaverlne soaking: before (3) and on cardiopulmonary bypass (4); free flow into a beaker (5); after anastomosis; on (6) and off cardiopulmonary bypass (7).

Pericardial substitutes were prepared from stable and degradable segmented polyurethanes and/or polyurethane/polyhydroxybutyrate composites.Polyurethane membranes implanted as pericardial substitute in the rabbit, did not activate adhesion and epicardial reaction over 3 months.Polyurethane/polyhydroxybutyrate membranes induced minimal adhesion or epicardial reaction, yet stimulated the growth of epithelium on the polymeric substrate and reduced the incidence of infection.