- Email: [email protected]
Practical and training aspects of teaching ventilatory resuscitation
134
Am. Heart
Annotations
twice that in Victoria. Queensland, lying partly within the tropics, has a much hotter climate than Victoria, and it was suggested that the elaboration of more concentrated urine could accentuate the presumed nephrotoxic action of phenacetin. The alternative possibility, that the Queensland population consumes greater quantities of analgesics, cannot be excluded because, although there is evidence that the current consumption of analgesics in Queensland is very high,12 no comparable information is available from Victoria. To date, it would appear, from the paucity of reported cases, that analgesic nephropathy is not an important problem in the United States. If it can be shown that the consumption of analgesics over the past 10 years is comparable with that in Australia, whereas large prospective autopsy surveys fail to show significant numbers of cases with the changes of analgesic nephropathy, it will be possible to conclude that there is some element in the Australian environment, or in Australian analgesics, that is peculiarly inimical to the kidney. Alastair Buwy, M.D., M.C.P.A. Princess Alexandra Hospital Brisbane, Australia REFERENCES 1.
Larsen, K., and Moeller, C. R.: A renal lesion caused by abuse of phenacetin, Acta Med. Scandinav. 163:153, 1959. 2. Kasanen, A., and Salmi, H. A.: Use of phenacetin and its detrimental effects on a series
Practical and training of teaching ventilatory
Today there is no doubt about the superior effect of mouth-to-mouth or mouth-to-nose breathing compared with the chest-compression methods. Nevertheless, various rescue organizations persist in teaching one or more of the chest-compression methods, and some organizations recommend them as being more effective than direct insufflation of the lungs by mouth! But these organizations do not consider that in the teaching of ventilatory resuscitation to laymen and paramedical personnel two problems are of practical and pedagogical importance: (1) the possible differences between the resuscitative methods in physical load on the rescuer if performed for a long period of time; and (2) adoption and memory of the different methods after a certain lapse of time. Therefore, we decided to choose mouth-to-mouth, mouth-to-nose, Holger Nielsen, Silvester, and
Jd>',
J.
1967
of hospital patients, Ann. Med. Int. Fenn. 50:195, 1961; abstract in J.A.M.A. 179:207, 1962. 3. Scott, J. T.: Phenacetin, aspirin, and kidney damage, Au. HEART J. 71:715, 1966. 4. Spuhler, O., and Zoilinger, H. W.: Die chronischinterstitielle Nephritis, Ztschr. klin. Med. 151:1, 1953. _ 5. Jacobs, L. A., and Morris, J. G.: Renal papillarv necrosis and the abuse of ohenacetin. M.T.* Australia 2:531, 1962. ’ 6. Ross, P.: A. P. C. as a cause of renal disease, M. J. Australia 2:539, 1962. 7. McCutcheon. A. D.: Renal damage and nhenacetin, M. J. Australia 2:543, 1962. ’ 8. Inglis, J. A.: Renal papillary necrosis and the abuse of phenacetin, M. J. Australia 2:932, 1962. 9. Burry, A. F., DeJersey, P., and Weedon, D.: Phenacetin and renal panillarv necrosis: Results of a prospective autopsy investigation, M. J. Australia 1673, 1966. 10. Dawborn, J. K., Fairley, K. F., Kincaid-Smith, P.. and Kinz. W. E.: The association of Deotic ulceration, chronic renal disease, and analgesic abuse, Quart. J. M. 35:69, 1966. 11. Burry, A. F.: A profile of renal disease in Queensland: Results of an autopsy survey, M. J. Australia 1:826. 1966. 12. Puriell, J.: A survey of phenacetin consumption in Biloela. Department of Social and Preventive Medicine Project No. 519, University of Queensland. __
“l
I
L
I
aspects resuscitation
Thomsen rescue breathing for a trial. Two or more of these methods are still being taught during the training program of rescue organizations in Germany. Volunteer soldiers, 19 to 23 years of age, who had never received any training in resuscitation underwent the trial. Ten volunteers were taught the 5 resuscitative methods. For the exhaled-air methods the Ambu-phantom was used, whereas the 3 manual methods were performed on other volunteers. Training for the manual methods lasted three times as long as did that for the exhaled-air methods. To determine the differences between the various methods in regard to the physical load borne by the rescuer, we believed it sufficient to measure pulse frequency, blood pressure, loss of weight, and increase in body temperature during the l-hour period that rescue breathing was performed. The sequence according to which the volunteers
prriormed the various methods was planned by means of the latin square in order to avoid spreading ‘actors which influence statistical significance. Every 10 minutes, pulse rate and blood pressure were measured. At the end of 1 hour of ventilation, ‘?rody weight and body temperature were compared with the values obtained prior to the trial. The evaluation performed by pluralized variant xaaigses separated for pulse rate, blood pressure, loss of weight, and body temperature showed ac-ording to the Friedmann test, by all criteria, no significant differences between the mouth-to-mouth and mouth-to-nose methods or between the 3 chest::ompression methods. Combining the mouth-tomouth and the mouth-to-nose methods into one group, and the 3 chest-compression methods into a second group, significant differences could be measured statistically. A much greater physical load is put on the rescuer when he is performing one of the chest-compression methods than one of the exhaled-air methods. Furthermore, we tried to discover the differences which probably exist between the 5 above-mentioned methods according to the adoption and memory of the volunteers after a certain lapse of time after rraining. It seems to be important to know which of the methods would be chosen by the rescuer in the event of a sudden catastrophe. Twenty-seven volunteers were trained with the same instruction equipment. Most of the training consisted of practical exercises combined with current correction of possible mistakes. After 5 months, the 27 volunteers were tested. They did not have prior knowledge of either the date or the nature of the test. One by one They were called into a separate room, and each,
eterograft
aortic
valves
Twenty-one heterograft aortic valve replacements’ have been performed over the last one year at St. Vincent’s Hospital, Melbourne. Heterografts have advantages over other implantable valves! and the reasons for our preference will be discussed after presentation of our clinical experience. A large valve bank of some 50 pig and calf valves has been readily established. Fresh valves have been collected under nonsterile conditions. Preservation and sterilization have been with buffered acid formaldehyde solution. The aortic sinuses of each heterograft are tightly packed with wool soaked in the preservative, in order to maintain the cusps and annulus in the natural shape. After several weeks, rhe valve is trimmed of all ventricular muscle, leaving a very strong, but thin, rim of annulus and aortic wall. Particular care is taken to measure the valve accurately, and at each operation 4 to 5 heterografts of varying sizes are made available. The unused
without nesitation, had to tell \b,n&i !dlOd ‘W would prefer. Beside rhe method or choice he tad !o perform ail of the other methods that he hati learned. Some of the most important criteria for evaluation aere free air-passage, sufficient breathing, and correct chest pressure. Xo significant diifrrences between the mouth-to-mouth and mouth-to-nose methods or between the chest-compression methods were found by the Friedmann test. We combined the 5 methods into two groups as described above. The superior value of the exhaled-air methods was proved subjectively and objectively. With the direct methods, 92.6 per cent of the opera tar-s were ciasscd 5s “correct,” and 7.4 per cent as ‘“satisfactory.” LVith the manual methods, 19.8 per cent were “correct,” 44.4 per cent were “satisfactory,” and 35.8 per cent were “unsatisfactory.” The]-e were almost eighteen times as many mistakes with tile manual methods as with the direct methods. It may be said that, besides the physiologic effects, the chest-compression methods ior ventilatory resuscitation do not prove to be satisfactory in regard to physical ioad or adoption and memory in the training of laymen. It was found that the exhaled-air methods are very mu.& superior to all other methods of artificial ventilation. it would seem that the training of laymen, and prtibably also of paramedical personnel, in chest-cornpressir?n methods is a doubtful procedure and a. wa~&e of time.
or human
v
va!ves are reiurned to their in&vii: al iir:s :‘OiitXll. ing the formaldehyde. They can and hate been inserted at subsequent operations. Careftll measurement of the host aortic annu!us is performed and a siightly larger heterograft is inserted. ‘The aim of this technique2 has been to ensure a campexnt valve. x single continuous suture, passing the rieetlle very deeply through both host annulus and heterograft rim, has given a satisfactory firm implantation. Interrupted or additional sutures have been rrsed in segments of the host rim that have been extensively decalcified. Our experiences with the calf and pig va:ves are expressed in Table 1. Of the 21 patients, 9 ha.:e :equired double-valve surgery, with repldcemens of both the aortic and mitral valves in 1 patients. Nineteen patients in this initiai series kit hospital. The 2 deaths were unrelated to the heterograft valve function. The one late death at 2 .morrths was due to
Am. Heart
Annotations
twice that in Victoria. Queensland, lying partly within the tropics, has a much hotter climate than Victoria, and it was suggested that the elaboration of more concentrated urine could accentuate the presumed nephrotoxic action of phenacetin. The alternative possibility, that the Queensland population consumes greater quantities of analgesics, cannot be excluded because, although there is evidence that the current consumption of analgesics in Queensland is very high,12 no comparable information is available from Victoria. To date, it would appear, from the paucity of reported cases, that analgesic nephropathy is not an important problem in the United States. If it can be shown that the consumption of analgesics over the past 10 years is comparable with that in Australia, whereas large prospective autopsy surveys fail to show significant numbers of cases with the changes of analgesic nephropathy, it will be possible to conclude that there is some element in the Australian environment, or in Australian analgesics, that is peculiarly inimical to the kidney. Alastair Buwy, M.D., M.C.P.A. Princess Alexandra Hospital Brisbane, Australia REFERENCES 1.
Larsen, K., and Moeller, C. R.: A renal lesion caused by abuse of phenacetin, Acta Med. Scandinav. 163:153, 1959. 2. Kasanen, A., and Salmi, H. A.: Use of phenacetin and its detrimental effects on a series
Practical and training of teaching ventilatory
Today there is no doubt about the superior effect of mouth-to-mouth or mouth-to-nose breathing compared with the chest-compression methods. Nevertheless, various rescue organizations persist in teaching one or more of the chest-compression methods, and some organizations recommend them as being more effective than direct insufflation of the lungs by mouth! But these organizations do not consider that in the teaching of ventilatory resuscitation to laymen and paramedical personnel two problems are of practical and pedagogical importance: (1) the possible differences between the resuscitative methods in physical load on the rescuer if performed for a long period of time; and (2) adoption and memory of the different methods after a certain lapse of time. Therefore, we decided to choose mouth-to-mouth, mouth-to-nose, Holger Nielsen, Silvester, and
Jd>',
J.
1967
of hospital patients, Ann. Med. Int. Fenn. 50:195, 1961; abstract in J.A.M.A. 179:207, 1962. 3. Scott, J. T.: Phenacetin, aspirin, and kidney damage, Au. HEART J. 71:715, 1966. 4. Spuhler, O., and Zoilinger, H. W.: Die chronischinterstitielle Nephritis, Ztschr. klin. Med. 151:1, 1953. _ 5. Jacobs, L. A., and Morris, J. G.: Renal papillarv necrosis and the abuse of ohenacetin. M.T.* Australia 2:531, 1962. ’ 6. Ross, P.: A. P. C. as a cause of renal disease, M. J. Australia 2:539, 1962. 7. McCutcheon. A. D.: Renal damage and nhenacetin, M. J. Australia 2:543, 1962. ’ 8. Inglis, J. A.: Renal papillary necrosis and the abuse of phenacetin, M. J. Australia 2:932, 1962. 9. Burry, A. F., DeJersey, P., and Weedon, D.: Phenacetin and renal panillarv necrosis: Results of a prospective autopsy investigation, M. J. Australia 1673, 1966. 10. Dawborn, J. K., Fairley, K. F., Kincaid-Smith, P.. and Kinz. W. E.: The association of Deotic ulceration, chronic renal disease, and analgesic abuse, Quart. J. M. 35:69, 1966. 11. Burry, A. F.: A profile of renal disease in Queensland: Results of an autopsy survey, M. J. Australia 1:826. 1966. 12. Puriell, J.: A survey of phenacetin consumption in Biloela. Department of Social and Preventive Medicine Project No. 519, University of Queensland. __
“l
I
L
I
aspects resuscitation
Thomsen rescue breathing for a trial. Two or more of these methods are still being taught during the training program of rescue organizations in Germany. Volunteer soldiers, 19 to 23 years of age, who had never received any training in resuscitation underwent the trial. Ten volunteers were taught the 5 resuscitative methods. For the exhaled-air methods the Ambu-phantom was used, whereas the 3 manual methods were performed on other volunteers. Training for the manual methods lasted three times as long as did that for the exhaled-air methods. To determine the differences between the various methods in regard to the physical load borne by the rescuer, we believed it sufficient to measure pulse frequency, blood pressure, loss of weight, and increase in body temperature during the l-hour period that rescue breathing was performed. The sequence according to which the volunteers
prriormed the various methods was planned by means of the latin square in order to avoid spreading ‘actors which influence statistical significance. Every 10 minutes, pulse rate and blood pressure were measured. At the end of 1 hour of ventilation, ‘?rody weight and body temperature were compared with the values obtained prior to the trial. The evaluation performed by pluralized variant xaaigses separated for pulse rate, blood pressure, loss of weight, and body temperature showed ac-ording to the Friedmann test, by all criteria, no significant differences between the mouth-to-mouth and mouth-to-nose methods or between the 3 chest::ompression methods. Combining the mouth-tomouth and the mouth-to-nose methods into one group, and the 3 chest-compression methods into a second group, significant differences could be measured statistically. A much greater physical load is put on the rescuer when he is performing one of the chest-compression methods than one of the exhaled-air methods. Furthermore, we tried to discover the differences which probably exist between the 5 above-mentioned methods according to the adoption and memory of the volunteers after a certain lapse of time after rraining. It seems to be important to know which of the methods would be chosen by the rescuer in the event of a sudden catastrophe. Twenty-seven volunteers were trained with the same instruction equipment. Most of the training consisted of practical exercises combined with current correction of possible mistakes. After 5 months, the 27 volunteers were tested. They did not have prior knowledge of either the date or the nature of the test. One by one They were called into a separate room, and each,
eterograft
aortic
valves
Twenty-one heterograft aortic valve replacements’ have been performed over the last one year at St. Vincent’s Hospital, Melbourne. Heterografts have advantages over other implantable valves! and the reasons for our preference will be discussed after presentation of our clinical experience. A large valve bank of some 50 pig and calf valves has been readily established. Fresh valves have been collected under nonsterile conditions. Preservation and sterilization have been with buffered acid formaldehyde solution. The aortic sinuses of each heterograft are tightly packed with wool soaked in the preservative, in order to maintain the cusps and annulus in the natural shape. After several weeks, rhe valve is trimmed of all ventricular muscle, leaving a very strong, but thin, rim of annulus and aortic wall. Particular care is taken to measure the valve accurately, and at each operation 4 to 5 heterografts of varying sizes are made available. The unused
without nesitation, had to tell \b,n&i !dlOd ‘W would prefer. Beside rhe method or choice he tad !o perform ail of the other methods that he hati learned. Some of the most important criteria for evaluation aere free air-passage, sufficient breathing, and correct chest pressure. Xo significant diifrrences between the mouth-to-mouth and mouth-to-nose methods or between the chest-compression methods were found by the Friedmann test. We combined the 5 methods into two groups as described above. The superior value of the exhaled-air methods was proved subjectively and objectively. With the direct methods, 92.6 per cent of the opera tar-s were ciasscd 5s “correct,” and 7.4 per cent as ‘“satisfactory.” LVith the manual methods, 19.8 per cent were “correct,” 44.4 per cent were “satisfactory,” and 35.8 per cent were “unsatisfactory.” The]-e were almost eighteen times as many mistakes with tile manual methods as with the direct methods. It may be said that, besides the physiologic effects, the chest-compression methods ior ventilatory resuscitation do not prove to be satisfactory in regard to physical ioad or adoption and memory in the training of laymen. It was found that the exhaled-air methods are very mu.& superior to all other methods of artificial ventilation. it would seem that the training of laymen, and prtibably also of paramedical personnel, in chest-cornpressir?n methods is a doubtful procedure and a. wa~&e of time.
or human
v
va!ves are reiurned to their in&vii: al iir:s :‘OiitXll. ing the formaldehyde. They can and hate been inserted at subsequent operations. Careftll measurement of the host aortic annu!us is performed and a siightly larger heterograft is inserted. ‘The aim of this technique2 has been to ensure a campexnt valve. x single continuous suture, passing the rieetlle very deeply through both host annulus and heterograft rim, has given a satisfactory firm implantation. Interrupted or additional sutures have been rrsed in segments of the host rim that have been extensively decalcified. Our experiences with the calf and pig va:ves are expressed in Table 1. Of the 21 patients, 9 ha.:e :equired double-valve surgery, with repldcemens of both the aortic and mitral valves in 1 patients. Nineteen patients in this initiai series kit hospital. The 2 deaths were unrelated to the heterograft valve function. The one late death at 2 .morrths was due to