Biomedical subjects
Publications and source records attributed to P Bloomfield.
A combined phonocardiographic and echocardiographic evaluation is presented of a patient with a mechanical prosthetic mitral valve. An intermittent sound equivalent to a prosthetic fourth sound is demonstrated and shown to be created by abrupt motion of the disc of the prosthesis with atrial systole.
Explore the source record for details and available documents.
Septal and lateral wall motion and septal thickening were evaluated with quantitative two-dimensional echocardiography in 20 patients who underwent cardiac surgery without complications. Postoperative mean ejection fraction (48 +/- 10%) measured by radionuclide ventriculography was unchanged from the preoperative value (45 +/- 8%). Mean postoperative systolic thickening of the septum (33 +/- 15%) was also unchanged from the preoperative value (26 +/- 10%). However, septal endocardial motion as measured by an external frame-of-reference (fixed-axis) system fell from a 22 +/- 10% mean percent shortening (MPS) of septal radii to a postoperative value of -8 +/- 15% (p less than .001). Fixed-axis analysis also led to an increase in MPS of lateral radii: preoperative 16 +/- 5%; postoperative 28 +/- 9% (p less than .001). With an internal frame-of-reference (floating-axis) system, which compensates for the effects of translation and rotation on wall motion, postoperative MPS of septal radii (22 +/- 10%) was unchanged from preoperative MPS (25 +/- 8%; p = NS). Similarly, MPS of lateral wall radii was unchanged (preoperative, 15 +/- 5%; postoperative, 12 +/- 5%; p = NS). Thus systolic translation of the ventricle accounts for abnormal postoperative septal motion seen in a fixed-axis system and can be corrected by a floating-axis system. These data have important implications for the noninvasive evaluation of regional wall motion after cardiac surgery. Systems using a fixed external frame of reference such as radionuclide ventriculography are prone to systematic error. A combination of systolic thickening analysis by two-dimensional echocardiography and analysis of endocardial motion by the floating-axis system is a more appropriate method for evaluating the effects of cardiac surgery on regional left ventricular function.
Four patients are described with rheumatoid disease with upper lobe fibrosis and cavitation which could not be explained by cavitation of rheumatoid nodules or any other recognized pulmonary manifestation of this disease.
The bronchodilator properties and side-effects of three doses of fenoterol (0.5 mg, 1 mg and 2 mg) and terbutaline (2.5 mg, 5 mg and 10 mg) were assessed in 12 patients with stable chronic asthma. The drugs were administered by intermittent positive pressure breathing (IPPB) in 40% oxygen via a Bennett ventilator. No differences likely to be of clinical significance were found between the effects of the three different dose levels of fenoterol and terbutaline, although terbutaline had a significantly greater duration of action. It is concluded that fenoterol 2 mg and terbutaline 10 mg can be administered by IPPB in 40% oxygen for the treatment of asthma.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
In December 1968 an emergency service was begun in Edinburgh to expedite admission to hospital of patients with severe acute asthma. During the first 10 years requests were made to admit 112 patients to a respiratory unit with provision for intensive care on 360 occasions. Four of the patients died of their disease, one in hospital and three before admission. It was thought that the death rate would have been much higher had conventional admission procedures been observed. Owing to ethical objections to a controlled trial it was not possible to obtain substantive proof that the service reduced deaths from asthma. Nevertheless, there was strong circumstantial evidence that organised facilities for the immediate admission to hospital of patients with a history of life-threatening attacks would result in fewer deaths at home. Earlier admission also apparently reduced hospital mortality and the number of patients requiring tracheal intubation and mechanical ventilation. It is concluded that there is a prima facie case for an emergency asthma admission serivce similar to that operating in Edinburgh to be established in all cities and large towns.
A double-blind crossover trial was carried out during 22 episodes of life-threatening asthma in 19 patients to compare salbutamol given as a 500 microgram intravenous injection and as a 0 . 5% solution administered by intermittent positive-pressure breathing (IPPB) for three minutes. Relief of pulsus paradoxus was significantly better after IPPB than the intravenous treatment. Both treatments significantly improved the peak expiratory flow rate. Salbutamol given intravenously produced a mean increase in heart rate of over 20 beats/min five minutes after treatment compared with the relief of tachycardia that occurred after administration by IPPB. Four patients had noticeable cardiovascular side effects after salbutamol given intravenously, but no such effects were noticed after administration by IPPB. Two patients withdrawn shortly after entry into the trial because of a worsening clinical condition had received intravenous salbutamol. It is concluded that salbutamol given by IPPB is better than that given by slow intravenous injection in severe acute asthma.
Explore the source record for details and available documents.