RESUMEN
The contribution of the Royal Navy to the development of modern submarine escape by free ascent, breathing air, from 1945 to the present time, is described. Much of the work is unpublished. Experiments in which goats were exposed to simulated escape pressure profiles while breathing air from 90 m to 300 m are described. The gradual testing of human subjects during such escape profiles is also reported up to real escapes by subjects from submarines lying at 180 m. Thus escapes are now feasible from almost anywhere on the continental shelf. Possible techniques of even deeper escape, i.e. hyperoxygenated air breathing, oxygen breathing, propulsion + retropulsion of the escaper, drogues + pressure retaining (2 atm abs) escape suits are briefly considered. The figures illustrate the Royal Navy series of animal and human, simulated and real escapes. Table I gives full details on human testing. Tables containing details of all goat exposures can be obtained from author.
Asunto(s)
Respiración , Medicina Submarina/historia , Animales , Enfermedad de Descompresión/historia , Cabras , Historia del Siglo XVIII , Historia del Siglo XIX , Historia del Siglo XX , Humanos , Narcosis por Gas Inerte/historia , Presión , Reino Unido , Ventiladores Mecánicos/historiaRESUMEN
The natural history of new and worsening angina pectoris was studied in 251 men aged under 70 years. Most were ambulant and all were referred by selected general practitioners to a special hospital clinic over two and a half years. Heart attacks developed in 39 patients, nine of whom died. Seventy-two per cent of the attacks occurred within six weeks of the onset or worsening of angina. Of the 212 patients who did not suffer myocardial infarction and who were clinically reviewed six months after their first attendance 66 had been pain free for the previous three months and 14 had experienced only infrequent attacks of angina. Of the 128 men aged under 65 years who were previously in employment 81% had returned to full-time work six months after their first attendance. A discriminant function analysis using many variables was made to develop a predictive index that would allow patients with new or worsening angina who were likely to develop serious cardiac complications to be identified. This did not prove possible, and the only predictive factor of significance was an increased cardiothoracic ratio. The syndrome of new and worsening angina has a low risk of early death, and many patients are symptom free six months later. In general, emergency coronary arteriography and surgery is not indicated.