Reduced complement activation with heparin-coated oxygenator and tubings in coronary bypass operations.

Complement activation after cardiopulmonary bypass is correlated with postoperative organ dysfunction. Heparin coating of the entire blood-contact surface of the cardiopulmonary bypass circuit has proved to reduce complement activation in vitro. A membrane oxygenator and tubing setup coated with functionally active heparin was compared with an uncoated, otherwise identical setup in 20 patients undergoing routine coronary bypass operations. The concentrations of C3 activation products and the terminal complement complex were measured in sensitive and specific enzyme immunoassays. Peak concentrations of C3 activation products were 90.1 (74.7 to 107.4) AU/ml (medians and 95% confidence intervals) and 52.4 (35.7 to 76.4) AU/ml with the uncoated and coated setups, respectively (p = 0.02). The corresponding concentrations of the terminal complement complex were 26.2 (20.1 to 37.5) AU/ml and 13.7 (11.1 to 25.1) AU/ml (p = 0.03). Blood loss from the mediastinal drains during the first 12 postoperative hours was 533 (416 to 975) ml in patients treated with the uncoated setup and 388 (313 to 579) ml in the coated treatment group (p = 0.06) and was significantly correlated with peak concentrations of the terminal complement complex (p = 0.01). There were no differences in neutrophil counts nor platelet numbers between the treatment groups. The approximate 45% reduction in complement activation with the heparin-coated cardiopulmonary bypass device indicates a substantial improvement of biocompatibility.

[Accidental hypothermia. Risk factors in 29 patients with body temperature of 30 degrees C and below]. / Aksidentell hypotermi. Risikofaktorer hos 29 pasienter med kroppstemperatur under 30 C grader.

29 patients with a body temperature below 30 degrees C (mean 26.4 degrees C) were treated during the period 1982-88, both years inclusive. Eight patients were severely hypotensive (systolic blood pressure less than 60 mm Hg) and two had ventricular fibrillation on admission. Bradycardia (less than 60 beats per minute) was noted in ten patients. 12 patients were rewarmed by surface warming, 17 by extracorporeal circulation with femoral cannulation. 22 patients (76%) were discharged alive. Age, sex, body temperature, method and rate of rewarming, serum electrolytes, acidosis and the use of blood components did not influence the outcome. Renal failure was the only complication associated with a fatal outcome. Severe hypotension on admission tended to increase mortality, but logistic regression analysis identified the mode of cooling as the only independent risk factor for death. A patient cooled indoors had an odd risk of 10.6 of hospital mortality compared to one found outdoors. For the sake of convenience, in hospitals with the available resources rewarming by extracorporeal circulation may be used in patients with circulatory arrest, since this is the easiest way to control and support failing circulation. In all other cases carefully monitored surface rewarming should be used as this necessitates less use of hospital resources and produces equally good results.

Effects of methylprednisolone on complement activation and leukocyte counts during cardiopulmonary bypass.

Generation of the complement activation products C3dg and terminal complement complex (TCC) and numerical changes in peripheral granulocytes (PMN) and lymphocytes were assessed in patients undergoing aortocoronary bypass surgery with extracorporeal circulation (ECC). Fluid from bronchial lavage performed preoperatively and 4 hours postoperatively was analyzed for granulocyte elastase activity and PMN content. Ten of the 20 patients received methylprednisolone (30 mg/kg b.w.) immediately before ECC. No difference was found between them and the control group regarding C3dg and TCC, and both groups showed similar postoperative decrease of peripheral blood lymphocytes. The postoperative PMN count in peripheral blood was significantly higher in the methylprednisolone group than in the controls from 12 hours onwards. In bronchial lavage fluid the postoperative PMN count was unaltered in the methylprednisolone group, but significantly increased in the controls. No granulocyte elastase activity was found before or after surgery in either group. The results indicated that methylprednisolone does not affect complement activation during cardiopulmonary bypass, but increases the granulocytes in peripheral blood postoperatively.

Surgical repair of isolated ventricular septal defects in the first year of life.

Since October 1975, 6 infants ranging in age from 5 to 9 months and weighing from 5.2 to 7.8 kg have been treated with primary closure of ventricular septal defect (VSD) at Ullevål Hospital. The indications for operation were large left-to-right shunts combined with persistence of heart failure in 4 patients, a large left-to-right shunt only in one and elevated pulmonary arterial resistance in one patient. Conventional cardiopulmonary bypass was used in all cases. There were no early or late deaths during the mean observation period of 17.3 months (range 3--25 months). One patient developed a recurrent VSD and was successfully re-operated on 8 months after the first operation; otherwise no signs of recurrence were found. The growth and weight gains have been satisfactory and the psychosomatic development of all the infants has been normal. All are in sinus rhythm with right bundle branch block in 4. Cardiac arrhythmias have not been in evidence.

On the technique of external cardiac compression.

ECG, arterial flow and pressure were recorded during external cardiac compression (ECC) in a patient whose heart had ceased beating. The patient was a 68-year-old female who remained comatose for 2 weeks after an emergency laparotomy for perforated diverticulitis of the colon. She developed sepsis, renal failure, and cardiopulmonary failure. During ECC, the pressure on the sternum was maintained for about 0.5 sec (sustained pressure technique), flow and mean arterial pressure were improved by 32 and 20%, respectively, as compared with flow and pressure obtained with a quick and more jerky compression. During spontaneous heart activity with a low blood pressure, a superimposed ECC improved both flow and mean arterial pressure. Calcium chloride and adrenaline injected into the right atrium increased the tone and contractile power of the heart and greatly improved flow and pressure when the heart was subsequently compressed during asystole.

[Expiratory air diversion during general anesthesia (author's transl)]. / Ausrüstung zum Absaugen von Exspirationsluft während der Narkose

A system for disposing of expiratory air containing volatile anaesthetic gases during anaesthesia is described. It consists of a reservoir bag and an adjustable suction connected to the outlet port of the anaesthesia machine or the nonbreathing valvel. A valve is incorporated which opens to the atmosphere if the reservoir bag should collaps completely, thus creating a slight vacumn in the system. Another valve, opens if the bag should become fully expanded and a slifht positive pressure develop in the system. Halothane concentrations in the "anaesthetists breathing zone" were negligible when this system was being used.