Cedric W. Deal

Complications of Ascending Aortic Intraaortic Balloon Pump Cannulation

Choice of a route of cannulation for intraaortic balloon counterpulsation during cardiopulmonary bypass is related to accessibility. In those patients in whom it is impossible to pass the intraaortic balloon pump (IABP) into the common femoral artery, ascending aortic cannulation is a rapid and direct method of insertion. Eight patients are described in whom ascending aortic IABP cannulation was undertaken to enable weaning from cardiopulmonary bypass after cardiac surgical procedures. The following problems were encountered: graft infection, aberrant cannulation of the left subclavian artery, left coronary artery embolism, and inability to close the sternum due to mechanical tamponade. A technique is described for insertion of the IABP using a polytetrafluoroethylene (Impra) graft and closed-chest decannulation. Although considerable morbidity and mortality are associated with ascending aortic cannulation, it is simple, fast, and effective, and should be considered for all patients requiring postoperative IABP support in whom peripheral vascular disease makes access difficult.

The use of ultra-low-dose aprotinin to reduce blood loss in cardiac surgery

One hundred patients due to undergo primary cardiac surgery were prospectively randomized to receive aprotinin or placebo. In the aprotinin group, 250,000 kallikrein inhibitory units (KIU) of aprotinin were added to the cardiopulmonary bypass prime solution. A further 250,000 KIU of aprotinin were infused intravenously over 30 minutes immediately before the start of cardiopulmonary bypass. The control group received 0.9% saline in equal volumes at identical times. The study was designed to have a 90% chance of demonstrating a 30% reduction in blood loss. No significant differences were found between the two groups. The median blood loss in the aprotinin group was 750 mL (interquartile range 556 to 1025 mL, 95% confidence interval 600 to 800 mL). In the control group, the median blood loss was also 750 mL (interquartile range 500 to 988 mL, 95% confidence interval 625 to 925 mL). In the aprotinin group, 12 patients received postoperative autotransfusion of shed mediastinal blood of median volume of 665 mL (interquartile range 500 to 925 mL, 95% confidence interval 450 to 1000 mL). In the control group, 14 patients received postoperative autotransfusion of mediastinal blood of median volume of 663 mL (interquartile range 600 to 800 mL, 95% confidence interval 600 to 700 mL). Five patients in the aprotinin group and seven patients in the control group required postoperative homologous blood transfusion. Reassessment of inclusion criteria showed a 19% reduction in blood loss in patients undergoing only aortocoronary bypass receiving aprotinin compared with controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of hypothermia on lung compliance

The changes in pulmonary compliance have been studied under conditions of total body hypothermia. Five groups of sheep were used; two groups were controls—one for the effects of anaesthesia and the other for normothermic biventricular bypass. The third group was cooled using a femoro-femoral arterio-venous shunt to 20°-23° C. The fourth group was cooled to 15° C. and rewarmed using the Drew technique. The excised lungs of the remaining sheep were studied at 37° and 15° C. (fifth group). The controls showed little change in compliance. The cooled animals showed a decrease in compliance. In the group subjected to hypothermia by the Drew technique, the rewarming phase initially brought a return towards normal compliance. As the temperature rose to 24°-30° C. the improvement in compliance ceased and thereafter compliance decreased for two hours after rewarming. Histologically the lungs were normal. There was no compliance change caused by cooling the excised lungs.

Hemodynamic effects of pulmonary air embolism

Abstract A large bolus of air was injected into the right atrium of sheep. The cardiac output, right ventricular pressure, and arterial PO 2 were studied. It was found that the cardiac output was quickly regained, in less than 10 minutes, despite relatively anoxic levels of arterial oxygen saturation. The cardiac output temporarily exceeded the preinjection level before settling back to this level. The right ventricular pressure rose, corresponding to the regained cardiac output, and then settled to its original levels. The arterial PO 2 fell precipitously and slowly started to rise over the period of study. Bubbles were seen in the coronary arteries during these experiments. A bubble trap was placed across the arch of the aorta which demonstrated that there was no major transpulmonary passage of air.

Intercostal lung hernia subsequent to harvesting of the left internal mammary artery

We report a case of an intercostal lung hernia developing subsequent to harvesting of the left internal mammary artery. Intercostal lung hernia is extremely rare, with most cases reported after blunt thoracic trauma. In the absence of symptoms, this was treated conservatively.

Bronchopulmonary precapillary blood flow during cardiopulmonary bypass.

Abstract A method of calculating the blood flow traversing bronchopulmonary anastomoses during cardiopulmonary bypass is presented, based on the CO 2 Fick principle. A total of 23 patients have been studied. Bronchial-alveolar flow varied with the type of cardiac lesion, and was often considerable, amounting to 11 per cent of the circulation in one patient with tetralogy of Fallot.

Repairing the degenerative anterior mitral leaflet

This is a consecutive, nonselected series of 18 patients with degenerative mitral regurgitation requiring a reparative operation on the anterior mitral leaflet. A new technique of double-breasting the two leaflets when flail septal segments are encountered is introduced.

Veno-arterial shunting in experimental pulmonary embolism

Abstract Cardiac output and pulmonary arteriovenous shunts were studied in two groups of sheep after pulmonary emboli. Hydrogensaline with a downstream platinum electrode was used as a dilution technique to measure cardiac output and transpulmonary shunting. The first group of sheep were given small clots and the second group one large clot. The recorded shunt was greater in these second group. The cardiac output fell after clot administration and the output/shunt ratio once established remained constant over 1 hour of study. In the animal given the largest clot compatible with survival the majority of the output traversed shunts, suggesting that this mechanism may avert right ventricular failure after massive pulmonary embolus.