Profiles of measured and perceived bronchodilation. A placebo-controlled cross-over trial comparing formoterol and salmeterol in moderate persistent asthma.

BACKGROUND AND OBJECTIVE: Long-acting beta(2)-agonists have acquired an indispensable position in the management of bronchial symptoms in patients with asthma. The objective of this study was to compare onset-of-action and clinical effectiveness of formoterol and salmeterol during 2 weeks of treatment. We also investigated the association between bronchodilator effects and perceived relieve of dyspnoea. METHODS: A multi-centre randomized double-blind placebo-controlled cross-over trial was performed in 35 subjects with moderate persistent asthma. Treatment periods existed of 2 weeks formoterol (12 microg bid), salmeterol (50 microg bid) and placebo, all administered by pressurized metered dose inhaler. FEV(1) and Visual Analogue Scale (VAS) scores were repeatedly measured until 180 min post-bronchodilation (post-BD), before as well as after each treatment period. Onset-of-action was defined as a >/=15% increase in FEV(1). Subjects kept diaries of morning and evening PEFR values and use of rescue bronchodilator. RESULTS: Formoterol and salmeterol both caused a significant increase in FEV(1) (0.45L [95% CI 0.01, 0.80] and 0.27L [95% CI 0.08, 0.62] respectively). At 3' post-BD, three times as many subjects demonstrated onset-of-action on formoterol compared to salmeterol (36% versus 13%, P = 0.063), at 6' post-BD 42% versus 27% (P = 0.063). VAS scores were similar for formoterol and salmeterol at pre-treatment assessment, but tended to be higher for formoterol after 2weeks treatment. No differences between formoterol and salmeterol were observed for PEFR values or use of rescue medication. 50% of the subjects preferred formoterol, 29% salmeterol (P < 0.001). Significant associations between FEV(1) and VAS ratings existed only at 10', 15' and 30' post-BD, not before or after these time points. CONCLUSION: The earlier described faster onset-of-action of formoterol as compared to a equipotent dosage of salmeterol was confirmed in this study. Perception of decreasing airflow obstruction may be delayed after acute bronchodilation.

The haemostatic effectiveness of autologous platelet rich plasma sequestered after heparin administration and institution of cardiopulmonary bypass.

Preoperative harvesting and postoperative reinfusion of autologous platelet rich plasma (PRP) has been reported to decrease blood loss as well as the requirement for homologous blood transfusion following cardiopulmonary bypass (CPB). We have developed a technique of intraoperative PRP sequestration which occurs during the initial period of CPB after the patient's circulation is supported and heparin has been given (PRP+). This process does not require any additional hardware, personnel or expense and it is performed without difficulty or complication. To evaluate the effect of PRP+ sequestration and reinfusion on blood loss and homologous blood requirement after CPB, we randomly assigned 126 consecutive patients undergoing elective open heart surgery into the experimental group 1 (PRP+) (n = 64) or the control (no platelet pheresis) group 2 (n = 52). A third group (n = 10) were not included in the randomization. Patients in group 3 had PRP prepared by conventional techniques (PRPc) prior to heparin administration and given to the patient after protamine infusion. Aggregation and activation studies were performed on the PRP+, PRPc, and blood bank platelets (BBP). Per cent aggregation of PRP in response to ADP was superior to that of BBP. There were no significant differences in ADP induced aggregation between PRP+ and PEPc. There was no significant difference in platelet activation (CD62) or number between the three groups. Patients infused with PRP+ showed significantly increased aggregation to ADP when compared with untreated patients 120 minutes after return to the ICW. Furthermore, more homologous haemostatic components (platelets/fresh frozen plasma) were required in the control group. We have demonstrated that collection of autologous PRP+ after administration of heparin does not interfere with its haemostatic effectiveness compared with PRPc prepared before the initiation of bypass. Moreover, this can be performed universally in haemodynamically unstable patients without any additional costs.

Cardiopulmonary bypass with adequate flow and perfusion pressures prevents endotoxaemia and pathologic cytokine production.

Endotoxin and cytokine inflammatory mediators comprise the afferent and efferent limbs of the 'acute phase response'. During cardiopulmonary bypass (CPB) there may be gut translocation of endotoxin and contact activation of lymphocytes. It has been hypothesized that the haemodynamic instability encountered following CPB is caused by the 'acute phase response'. In this study we attempted to quantify the acute phase response in patients undergoing open-heart surgery and determine the influence of these cytokines on perioperative morbidity. Four perioperative blood samples were drawn from 20 consecutive patients undergoing coronary artery bypass grafting (CABG). These samples were assayed for endotoxin and four cytokines. In all cases the cardiac index was maintained > 2.4 l/min/m2 during nonpulsatile normothermic bypass (37 degrees C) and > 1.8 l/min/m2 during nonpulsatile hypothermic bypass (28 degrees C), and the perfusion pressure > 60 mmHg. Endotoxin was not detected in any of the test samples despite positive nonpatient controls. Interleukin 6 (IL-6) and tumour necrosis factor (TNF) were not detected despite an assay sensitivity of 80 and 10 pg/ml, respectively. TNF was detectable with an assay sensitivity of 0.5 pg/ml although there were no significant differences within the group. Interleukin 1 (IL-1) was detected (range = 0.98 - 9.09 ng/ml) in patients and again there were no trends within the group. The platelet activating factor (PAF) values peaked at crossclamp release (1.3 ng/ml versus a baseline of 0.2 ng/ml); however, there was no significant difference within the study.

Intraoperative procurement of autologous fibrin glue.

A method of intraoperative procurement of autologous fibrin glue is described. The relative efficacy of our autologous preparation is compared with that of fibrin glue made with homologous cryoprecipitate. Experimentally, the fibrinogen content and the strength are less than those found in cryoprecipitate and appear related to the fibrinogen content of the autologous plasma used as substrate in the fibrin glue reaction. Clinically, no significant differences are noted in the performance of autologous fibrin glue. We believe the absence of the risk of blood-borne infection with the autologous product is a major advantage.