Summary A radioimmunoassay was developed to detect IgE antibodies to the anaesthetic induction agent thiopentone. Significant levels of thiopentone‐reactive IgE antibodies were found in the sera of two patients who had experienced life‐threatening anaphylactoid reactions following administration of the drug. Inhibition experiments revealed that cross‐reactivity occurs between the drug‐reactive IgE antibodies and four barbiturate analogues pentobarbitone, phenobarbitone, barbitone and methohexital. The assay should supplement skin testing for the detection of patients with potentially lethal sensitivity to thiopentone.

Platelet-rich plasma (PRP) is postulated to decrease postoperative mediastinal chest tube drainage (MCTD) and allogeneic blood transfusions (ABT) after surgery with cardiopulmonary bypass. However, recent metaanalysis of the literature reveals that few good quality (therapeutic yield) trials that show a benefit have been published. The potential hemodynamic instability caused by plateletpheresis has not been emphasized. We studied the effect of plateletpheresis on MCTD, ABT, and hemodynamic stability in reoperative coronary artery bypass graft patients, a group perceived to be at high risk for ABT. Ninety patients were randomly assigned to Pheresis or Control groups. epsilon-Aminocaproic acid was given to all patients. Hemodynamic instability was assessed by degree of volume and inotrope resuscitation required. Part of the sequestered platelet volume was used to make autologous platelet gel, which was applied as a wound sealant. Mean pheresis yield was 30% +/- 7% of the circulating platelet mass or 6.4 +/- 2.2 allogeneic platelet unit equivalents. Total MCTD did not differ between the groups. There were no differences in mean packed red blood cell, platelet, and plasma transfusion rates. Overall, 52% of the Pheresis group received ABT, versus 55% of the Control group. Fifty-three percent of the Pheresis group patients exhibited significant hemodynamic instability, versus 27% of the Control group (P < 0.05). This study was unable to show any reduction in MCTD or ABT, although the plateletpheresis technique may offset platelet dysfunction caused by aspirin or increased blood exposure to nonbiologic surfaces, or it may compensate for lack of antifibrinolytic use. The significantly increased incidence of hemodynamic instability in the Pheresis group means that the risk/benefit ratio must be determined for individual cardiac surgical units.

Twenty-four cardiopulmonary bypass (CPB) per fusion units around Australia were surveyed to determine the characteristics of CPB per fusion as practised in Australia in 1992. Twenty completed survey forms were received. Findings were compared with those of a similar study performed by one of the authors for the year 1986. The field of CPB per fusion continues to expand both in terms of numbers of cases and increasing technological complexity. The major technological changes evident are the now clear dominance of membrane over bubble oxygenators and the proliferation of inline S V 02 monitoring devices. The greatest change in practice has been to the virtually universal use of cardioplegia. There remains considerable variation in the composition of the cardioplegia solutions used in the responding units. A range of minimum per fusion pressures for CPB is noted, whereas most units employ similar minimum per fusion flows. Methods of central nervous system and renal protection are mainly hypothermia and diuretics, respectively, with a scattering of other techniques. Staffing of CPB per fusion units is essentially unchanged since 1986 and at least five units had no medical per fusionist appointed in 1992.

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