Hydroxyethyl starch 130/0.4 versus modified fluid gelatin for cardiopulmonary bypass priming: the effects on postoperative bleeding and volume expansion needs after elective CABG.

UNLABELLED: Concerned about high dose starches and potential coagulopathy, we performed a double blinded randomised prospective study on the influence of gelatine or 6% HES 130/04 pump prime on postoperative blood loss and transfusion requirements after CABG surgery. METHODS: After informed consent, 157 electively scheduled patients were randomly allocated to 6% HES (n=85) or gelatine (n=72) CPB priming. Postoperatively, chest tube drainage was noted hourly during the first 24 hours and every unit of colloid, albumin, FFP or Packed Red Cells needed to maintain hemodynamic stability was carefully registered. Blood losses were standardised as ml blood loss/kg body weight. Three patients in the HES group were excluded from the study because of postoperative haemorrhage of pure surgical origin. Data analysis consisted in unpaired t-test and Fisher exact test where appropriate. RESULTS: Chest tube drainage was significantly higher at 1 hour in the HES group (2.38 ml/kg vs. 3.15 ml/kg, p = 0.03). At 24 hours, total blood loss was still higher in the HES group without reaching statistical significance (p = 0.07). Albumin supplements occurred more frequently in the HES group between 2 and 3 hours postoperatively (p = 0.02). Total artificial colloid supplement was significantly higher in the gelatin group (13.36 versus 8.96 ml/kg, p < 0.001). There were no differences in the number of packed red cells, fresh frozen plasma or platelets transfused between the two groups. CONCLUSION: 6% HES 130/0.4 is a safe alternative to gelatine pump prime with a volume effect persisting longer in the postoperative phase, mandating less volume expansion with artificial colloid during the first 24 postoperative hours and not causing additional allogeneic blood component exposure.

Transition time: a new parameter coinciding with fair intubating conditions.

With rocuronium optimal intubating conditions are earlier achieved than the adductor pollicis muscle onset time. Using the transition time we defined a better parameter for clinical relaxation. The onset of relaxation was determined in 20 patients. After a stable response was achieved with a 0.1 Hz single twitch stimulation 0.60 mg/kg rocuronium was injected. The three different stades during the onset of relaxation were determined. These are the lag time, transition time (transition between second and third phase) and onset time. Whether the transiton time corresponds with optimal intubating conditions was evaluated in 40 other patients. The median transition time was 67.4 (P25:52.5, P75:76.3) seconds with a corresponding relaxation of 76.2 (P25:81.4, P75:70.7)%. The intubating conditions were significantly better at a relaxation level corresponding with the transition time. We conclude that the transition time approximates the intubating time and corresponds with fair intubating conditions. This parameter can be preferred to define the moment with optimal intubating conditions.

In vitro evaluation of the effect of profound haemodilution with hydroxyethyl starch 6%, modified fluid gelatin 4% and dextran 40 10% on coagulation profile measured by thromboelastography.

Synthetic colloids have been implicated as a cause of coagulopathy when administered in large quantities. The effect of profound haemodilution (50%) on coagulation profile was measured in vitro by thromboelastography. Blood samples were taken from 11 ASA grade 1 patients prior to induction of anaesthesia for elective surgery. Each sample was simultaneously tested in four different preparations: undiluted blood (control sample); blood diluted with hydroxyethyl starch 6%; blood diluted with modified fluid gelatin 4%; blood diluted with dextran 40 10%. There was a significant decrease in reaction time in the preparations treated with hydroxyethyl starch 6% and modified fluid gelatin 4%, reflecting activation of initial fibrin formation. A significant increase in clot formation time was noted in the hydroxyethyl starch 6%-treated preparations. There was also a significant decrease in clot formation rate and maximum amplitude in the hydroxyethyl starch 6% group. Clot formation time, clot formation rate and maximum amplitude did not change in the modified fluid gelatin 4% group. Profound haemodilution with dextran 40 10% exerted extreme effects on the measured variables, very often resulting in a straight line on the thromboelastography profile.

Operative closure of patent ductus arteriosus in the neonatal intensive care unit.

Preterm infants undergoing surgical closure of patent ductus arteriosus are usually critically ill and are suffering from many concomitant diseases. The high risk of increased morbidity in transferring them from the neonatal intensive care unit (NICU) to a distant operating room is generally recognized. For this reason we report our experience in 33 premature infants with patent ductus arteriosus who have been operated in the NICU over a six-year period. There were no operative or immediate postoperative deaths and the 30 days hospital mortality was 6%. Based upon these findings we can confirm that operative closure of PDA can be performed safely in the NICU.

Evaluation of the anticoagulant properties of aprotinin in vitro.

The interaction of aprotinin with normal coagulation was studied in blood samples obtained from 10 healthy subjects. Each sample was simultaneously tested in four different preparations: NaCl-treated blood: 0.03 mL 0.9% NaCl in 0.33 mL blood; aprotinin treated blood: 0.33 mL blood+aprotinin in 0.03 mL in aliquots to obtain a final blood concentration of respectively 50 KIU mL-1; 100 KIU mL-1 and 200 KIU mL-1. The coagulation process was analysed by thromboelastography. R-time, reflecting intrinsic coagulation, increased in a dose dependent manner between NaCl-treated and aprotinin-treated blood. These findings suggest a dose dependent impairment of intrinsic coagulation by aprotinin.

Rapidly progressive pulmonary artery hypertension and end-stage liver disease.

Pulmonary hypertension is a recognized but unusual complication of liver disease. It can complicate the perioperative course of liver transplantation. Mild to moderate pulmonary hypertension is generally well tolerated during the procedure and does not appear to contribute to mortality. Since the pulmonary vascular disease may progress rapidly, it may have advanced to the point of irreversibility at the time of surgery. So, patients with known moderate pulmonary hypertension should have pulmonary arterial catheterisation immediately prior to transplantation. If pulmonary artery hypertension has become severe, then a preoperative trial of vasodilators is warranted. If this fails, the procedure should be cancelled. We present a patient with alcoholic liver cirrhosis in whom a rapidly progressive pulmonary hypertension made liver transplantation impossible.