British journal of anaesthesia
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We have compared the effects of progressive (30% and 60%) in vitro haemodilution with hydroxyethyl starch (HES), gelatin (GEL) and albumin (ALB) with haemodilution using 0.9% saline in 96 patients by thrombelastography. Haemodilution with HES, GEL and ALB significantly (P < 0.05) compromised coagulation time (k), angle alpha and maximal amplitude (MA), with HES having the most negative effect at 30% and 60% haemodilution (P < 0.05). ⋯ Prolongation of reaction time (r) was found for HES at 30% and 60% haemodilution and for ALB at 60% haemodilution and an increase in clot lysis by HES, GEL and ALB became evident. We conclude that HES, GEL and ALB compromised blood coagulation, while the maximum effect was found with HES.
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The use of inhaled nitric oxide in the critically ill has increased significantly over the past few years but little published information exists on standards for current practice. Sixty-four intensive therapy units in the UK were surveyed by questionnaire from which 54 (84.4%) satisfactory replies were received. We present the survey results and put forward recommendations based on current literature and our own clinical experience for the safe use of inhaled nitric oxide.
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The usefulness and optimal timing of laboratory coagulation tests before obstetric extradural analgesia are controversial. Moreover, the significance of mild coagulation abnormalities during pregnancy remains unclear. We have assessed the reliability of coagulation tests performed several weeks before delivery as predictors of coagulation abnormalities during labour. ⋯ Only three had been detected by the first sample. Platelet count less than 100 x 10(9) litre-1 or fibrinogen concentration less than 2.9 g litre-1 during labour were associated with an increase in the incidence of postpartum haemorrhage (odds ratio = 19.7). We conclude that a platelet count several weeks before delivery was not reliable in predicting thrombocytopenia during labour and that women with mild coagulation abnormalities in early labour may need special attention regarding the risk of postpartum haemorrhage.
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We have determined the pharmacokinetics and pharmacokinetic-pharmacodynamic relationship of rocuronium in infants and children. We studied infants (n = 5, 0.1-0.8 yr) and children (n = 5, 2.3-8 yr), ASA II, in the ICU while undergoing artificial ventilation under i.v. anaesthesia with an arterial cannula in situ and the EMG of the adductor pollicis muscle was monitored. Rocuronium 0.06 (infants) and 0.09 (children) mg kg-1 min-1 was given i.v. over +/- 5 min until 85% neuromuscular block was obtained. ⋯ Infants differed from children in plasma clearance (4.2 (0.4) vs 6.7 (1.1) ml min-1 kg-1), distribution volume at steady state (231 (32) vs 165 (44) ml kg-1), mean residence time (56 (10) vs 26 (9) min), concentration in the effect compartment at 50% block (1.2 (0.4) vs 1.7 (0.4) mg litre-1) and the slope of the concentration-effect relationship (5.7 (1.3) vs 3.9 (0.5)). Calculated mean ED90 values were 0.26 and 0.34 mg kg-1 for infants and children, respectively. The time course of neuromuscular block after equipotent doses did not differ.