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The transfusion of blood products, especially red cell concentrates, in critically ill patients is controversial and benefits of red cell concentrate transfusion in these patients have not been clearly demonstrated. We performed a prospective observational study to compare best evidence to actual practice of red cell concentrate and other blood product administration in an intensive care unit (ICU) in a university-associated tertiary hospital. All primary admissions during a 28-day period were included in the study and data collected included transfusion of red cells and blood products, patient demographics and ICU and hospital outcome. One hundred and seventy-five admissions were studied; 44% followed cardiac surgery. Forty-one patients (23%) received red cell concentrates in ICU, with 120 units transfused in 61 separate episodes. Other blood product usage was minimal. One third (20/61) of red cell concentrate transfusion episodes were of a single unit. The mean (±SD) pre-transfusion haemoglobin was 7.9±1.1 g/dl. Despite transfusion, such patients left ICU with a lower haemoglobin concentration compared with untransfused ICU patients (9.5±1.0 versus 10.5±2.1 g/dl; P<0.001). Cardiac surgical patients received similar red cell transfusion to general ICU patients. Univariate analysis showed no significant difference in mortality between patients who did or did not receive red cell concentrate transfusion (P=0.17). However, red cell concentrate transfusion was associated with a reduced adjusted mortality both in ICU (OR 0.13, 95% CI 0.02-0.73) and in hospital at 28 days (OR 0.10, 95% CI 0.02-0.58). The low red cell concentrate and blood product usage in our ICU were consistent with restrictive transfusion practice and selective red cell concentrate transfusion was associated with reduced mortality.

Summary Although calcium antagonists such verapamil are used primarily in cardiovascular disease, they appear to relax smooth muscle generally. Therefore, the possibility that verapamil might have bronchodilator properties was explored using the guinea‐pig tracheal ring technique. Verapamil was found to produce considerable tracheal smooth muscle relaxation from a threshold concentration of 2 × 10−7M and with maximum effect at 10−3M. The responses to the contractile agonists histamine and prostaglandin F2α and especially methacholine and serotonin were substantially reduced by prior administration of verapamil. Verapamil 2 × 10−4M was equally effective as isoprenaline 10−8M in producing 50% maximum direct relaxation but was more effective than isoprenaline as an antagonist of the contractile agonists, methacholine, histamine and serotonin, but not prostaglandin F2α. Verapamil abolished the contractile responses to barium chloride. It is concluded that, although verapamil was not very potent as a direct bronchodilator, it could potentially be of prophylactic benefit in asthma because of its efficacy as an antagonist of common contractile agonists.

The possible beneficial effect of aprotinin, a broad protease inhibitor, on the incidence and outcome of ARDS was examined in two complementary studies. In the first study, the effect of aprotinin was assessed in 147 patients admitted with multiple trauma or shock. In the 57 patients who developed ARDS, mortality was significantly less in those who had previously received aprotinin (8/20, 40%) than in those who had not (26/37, 70%). Although both treatment groups were well matched, this was a retrospective study and a second prospective, randomised, controlled study was therefore carried out. In 78 patients at risk of ARDS, there was no significant difference between treated and control patients in the incidence, duration or severity of ARDS, or in mortality or other major complications. It is concluded that aprotinin is not effective in improving any aspect of ARDS or its outcome in seriously ill patients.

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