Thorax
-
The indications for intra-aortic balloon pumping vary widely from country to country and from one cardiac surgical unit to another. Its use in Glasgow from 1976 to 1983 in 63 patients has been reviewed. Six of the patients (9.5%) had the intra-aortic balloon inserted before cardiac surgery, 43 (68.2%) at the time of surgery, and 14 (22.2%) in the postoperative period. ⋯ Seventeen patients (27%) survived from six weeks to 3.3 years after receiving the support of intra-aortic balloon pumping. There was major morbidity in 11 patients (17%), all of whom developed degrees of ischaemia due to ileofemoral arterial obstruction in the leg in which the balloon was inserted. The conservative use of the method in this centre is reflected in the high mortality of these patients.
-
We have studied the efficacy of three devices designed to conserve oxygen delivered to patients with hypoxic chronic bronchitis and emphysema. Devices A and B are valve systems, which deliver oxygen only during inspiration. Device C is a modified nasal prongs system incorporating a "moustache reservoir" (Oxymizer, Chad Therapeutics Inc, Woodland Hills, California), which is claimed to produce a higher arterial oxygen saturation (SaO2) from a given flow of oxygen than does continuous delivery through nasal prongs. ⋯ The flow characteristics of device A were likely to be the cause of this failure to conserve oxygen. Device C produced a higher mean rise in SaO2 than did standard nasal prongs at all oxygen flow rates, and was able to achieve the same rise in SaO2 as standard nasal prongs with a small (25-33%) saving in oxygen delivery. There was, however, considerable variation between patients in the oxygen saving efficiency of device C, with little or no oxygen saving in seven of the 12 patients studied.
-
Recently nebulised antibiotics (gentamicin and carbenicillin) have been used successfully to treat respiratory tract infection in patients with cystic fibrosis. No information exists, however, on the choice of nebuliser or the ideal mode of operation with antibiotic solutions, which are often viscous. The aerosol output, droplet size, and nebulisation time were assessed for four common brands of jet nebuliser (Bird, DeVilbiss, Inspiron, and Upmist) used to nebulise 2 ml (80 mg) and 4 ml (160 mg) of gentamicin solution (Garamycin, Kirby-Warrick) at four compressed gas flow rates (6, 8, 10, and 12 1 . min-1). ⋯ The output of drug in droplets of below 5 micron diameter ranged from 7.2 (SE 0.4) to 71.4 (4.3) mg, according to the type of nebuliser, flow rate, and volume fill. These studies suggest that for optimal drug delivery 4 ml gentamicin solution should be nebulised either at a fixed flow rate of 10-12 1 . min-1 or with a high flow compressor. Previous unsatisfactory clinical results with antibiotic aerosols may have been due in part to incorrect choice of nebuliser or inappropriate operating conditions, or both.