The effects of 2% and 4% sevoflurane in oxygen and nitrous oxide for induction of anaesthesia in 60 unpremedicated elderly patients was compared to those obtained during an intravenous Thiopentone induction. Intravenous induction induced anaesthesia in 27 +/- 5 seconds, significantly faster than a 2% or 4% sevoflurane induction (109 +/- 36 and 71 +/- 24 seconds respectively). One patient in both the thiopentone and 2% sevoflurane groups, and 2 patients in the 4% sevoflurane group coughed during induction. The postinduction reduction in mean arterial pressure was greatest in the thiopentone group followed by the 4% and the 2% sevoflurane groups. Heart rate changes were minimal in all groups. We conclude that 2% or 4% sevoflurane offered suitable conditions for induction of anaesthesia in the elderly with minimal cardiovascular derangement.
Oxygen consumption values calculated by Fick's principle (cVO2) were compared to simultaneously obtained values measured by indirect calorimetry (mVO2) in two groups of patients; post-coronary artery bypass graft (post-CABG) and septic shock. In both groups of patients, oxygen consumption values derived using indirect calorimetry were higher than that from Fick's principle. Whilst the bias obtained between the two methods of measurement were of acceptable amount clinically, the limits of agreement were wide: -57 to 51 ml.min-1.m-2 in the post-CABG group and -101 to 67 ml.min-1.m-2 in the group of septic patients; indicating that significant differences exist between paired individual values such that cVO2 and mVO2 were not interchangeable in this study.
Two major water-insoluble proteins are located on the surface of rubber particles in Hevea brasiliensis latex. A 14.6 kd protein (Hev b 1), found mainly on large rubber particles (> 350 mm in diameter), and a 24 kd protein (Hev b 3), found mainly on small rubber particles (average diameter, 70 nm), are recognized by IgE from patients with spina bifida and latex allergy. Although Hev b 1 (also called the rubber elongation factor [REF]) has previously been reported as a major latex allergen, this conclusion has been disputed on the basis of results from other studies. The allergenicity of Hev b 1 is verified in this study by testing the recombinant protein generated from its gene. Because allergenicity is confined to patients with spina bifida and not observed in adults sensitive to latex, it is not a major latex allergen. The identification of Hev b 3 as another allergen originating from rubber particles is confirmed by immunogold labeling and electron microscopy. Observations with the monoclonal antibody USM/RC2 developed against Hev b 3 show that the protein has a tendency to fragment into several polypeptides of lower molecular weight (from 24 kd to about 5 kd) when stored at -20 degrees C. There is also indication of protein aggregation from the appearance of proteins with molecular weights greater than 24 kd. Fragmentation of Hev b 3 is induced immediately on he addition of latex B-serum, which is normally compartmentalized in the lutoids in fresh latex. In the preparation of ammoniated latex (used for the manufacture of latex products), the lutoids are ruptured, and the released B-serum reacts with Hev b 3 on the rubber particles to give rise to an array of low molecular weight polypeptides that are allergenic to patients with spina bifida.