Search

Your search keyword '"Kays, C"' showing total 45 results
Start Over Author "Kays, C"
45 results on '"Kays, C"'

12. Effect of changing the gravity vector on respiratory output and control

Author

Dellaca, R, Bettinelli, D, Kays, C, Techoueyres, P, Lachaud, J, Vaida, P, Miserocchi, G, Dellaca, RL, Lachaud, JL, MISEROCCHI, GIUSEPPE ANDREA, Dellaca, R, Bettinelli, D, Kays, C, Techoueyres, P, Lachaud, J, Vaida, P, Miserocchi, G, Dellaca, RL, Lachaud, JL, and MISEROCCHI, GIUSEPPE ANDREA

Abstract

We studied the respiratory output in five subjects exposed to parabolic flights [gravity vector 1, 1.8 and 0 gravity vector in the craniocaudal direction (G(z))] and when switching from sitting to supine (legs bent at the knees). Despite differences in total respiratory compliance (highest at 0 G(z) and in supine and minimum at 1.8 G(z)), no significant changes in elastic inspiratory work were observed in the various conditions, except when comparing 1.8 G(z) with 1 G(z) (subjects were in the seated position in all circumstances), although the elastic work had an inverse relationship with total respiratory compliance that was highest at 0 G(z) and in supine posture and minimum at 1.8 G(z). Relative to 1 G(z), lung resistance (airways Plus lung tissue) increased significantly by 52% in the supine but slightly decreased at 0 G(z). We calculated, for each condition, the tidal volume changes based on the energy available in the preceding phase and concluded that an increase in inspiratory muscle output occurs when respiratory load increases (e.g., going from 0 to 1.8 G(z)), whereas a decrease occurs in the opposite case (e.g., from 1.8 to 0 G(z)). Despite these immediate changes, ventilation increased, going to 1.8 and 0 G(z) (up to approximate to23%), reflecting an increase in mean inspiratory flow rate, tidal volume, and respiratory frequency, while ventilation decreased (approximately -14%), shifting to supine posture (transition time similar to15 s). These data suggest a remarkable feature in the mechanical arrangement of the respiratory system such that it can maintain the ventilatory output with small changes in inspiratory muscle work in face of considerable changes in configuration and mechanical properties.

Published
2004

13. Effect of gravity on chest wall mechanics

Author

Bettinelli, D, Kays, C, Bailliart, O, Capderou, A, Techoueyres, P, Lachaud, J, Vaida, P, Miserocchi, G, Lachaud, JL, Bettinelli, D, Kays, C, Bailliart, O, Capderou, A, Techoueyres, P, Lachaud, J, Vaida, P, Miserocchi, G, and Lachaud, JL

Abstract

Chest wall mechanics was studied in four subjects on changing gravity in the craniocaudal direction (G(z)) during parabolic flights. The thorax appears very compliant at 0 G(z): its recoil changes only from -2 to 2 cmH(2)O in the volume range of 30-70% vital capacity (VC). Increasing G(z) from 0 to 1 and 1.8 G(z) progressively shifted the volume-pressure curve of the chest wall to the left and also caused a fivefold exponential decrease in compliance. For lung volume <30% VC, gravity has an inspiratory effect, but this effect is much larger going from 0 to 1 G(z) than from 1 to 1.8 G(z). For a volume from 30 to 70% VC, the effect is inspiratory going from 0 to 1 G(z) but expiratory from 1 to 1.8 G(z). For a volume greater than ∼70% VC, gravity always has an expiratory effect. The data suggest that the chest wall does not behave as a linear system when exposed to changing gravity, as the effect depends on both chest wall volume and magnitude of G(z)

Published
2002

14. Effect of gravity and posture on lung mechanics

Author

Bettinelli, D, Kays, C, Bailliart, O, Capderou, A, Techoueyres, P, Lachaud, J, Vaida, P, Miserocchi, G, Lachaud, JL, Bettinelli, D, Kays, C, Bailliart, O, Capderou, A, Techoueyres, P, Lachaud, J, Vaida, P, Miserocchi, G, and Lachaud, JL

Abstract

The volume-pressure relationship of the lung was studied in six subjects on changing the gravity vector during parabolic flights and body posture. Lung recoil pressure decreased by similar to2.7 cmH(2)O going from 1 to 0 vertical acceleration (G(z)), whereas it increased by similar to3.5 cmH(2)O in 30degrees tilted head-up and supine postures. No substantial change was found going from I to 1.8 G(z). Matching the changes in volume-pressure relationships of the lung and chest wall (previous data), results in a decrease in functional respiratory capacity of similar to580 ml at 0 G(z) relative to 1 G(z) and of similar to1,200 ml going to supine posture. Microgravity causes a decrease in lung and chest wall recoil pressures as it removes most of the distortion of lung parenchyma and thorax induced by changing gravity field and/or posture. Hypergravity does not greatly affect respiratory mechanics, suggesting that mechanical distortion is close to maximum already at 1 G(z). The end-expiratory volume during quiet breathing corresponds to the mechanical functional residual capacity in each condition.

Published
2002

17. Effect of gravity on chest wall mechanics

Author

Bettinelli, D., primary, Kays, C., additional, Bailliart, O., additional, Capderou, A., additional, Techoueyres, P., additional, Lachaud, J. L., additional, Vaïda, P., additional, and Miserocchi, G., additional

Published
2002
Full Text
View/download PDF

21. Effect of changing the gravity vector on respiratory output and control.

Author

Dellacá, R. L., Bettinelli, D., Kays, C., Techoueyres, P., Lachaud, J. L., Vaida, P., and Miserocchi, G.

Subjects
REDUCED gravity environments, RESPIRATION, RESPIRATORY organs, MUSCLES, AIRWAY (Anatomy), POSTURE
Abstract

We studied the respiratory output in five subjects exposed to parabolic flights [gravity vector 1, 1.8 and 0 gravity vector in the craniocaudal direction (Gz)] and when switching from sitting to supine (legs bent at the knees). Despite differences in total respiratory compliance (highest at 0 Gz and in supine and minimum at 1.8 Gz), no significant changes in elastic inspiratory work were observed in the various conditions, except when comparing 1.8 Gz with 1 Gz (subjects were in the seated position in all circumstances), although the elastic work had an inverse relationship with total respiratory compliance that was highest at 0 Gz and in supine posture and minimum at 1.8 Gz. Relative to 1 Gz, lung resistance (airways plus lung tissue) increased significantly by 52% in the supine but slightly decreased at 0 Gz. We calculated, for each condition, the tidal volume changes based on the energy available in the preceding phase and concluded that an increase in inspiratory muscle output occurs when respiratory load increases (e.g., going from 0 to 1.8 Gz), whereas a decrease occurs in the opposite case (e.g., from 1.8 to 0 Gz). Despite these immediate changes, ventilation increased, going to 1.8 and 0 Gz (up to ≈23%), reflecting an increase in mean inspiratory flow rate, tidal volume, and respiratory frequency, while ventilation decreased (approximately -14%), shifting to supine posture (transition time ∼15 s). These data suggest a remarkable feature in the mechanical arrangement of the respiratory system such that it can maintain the ventilatory output with small changes in inspiratory muscle work in face of considerable changes in configuration and mechanical properties. [ABSTRACT FROM AUTHOR]

Published
2004

23. Effective carbon dioxide washout by high-frequency mechanical ventilation.

Author

Jebria, A. and Kays, C.

Abstract

High-frequency ventilation was investigated in a model of the central airways of a human lung cast enclosed in a spherical cavity (alveolí). The experiments were performed at high frequencies (5, 10, 15 and 20 Hz) and tidal volumes (50, 90 and 120 cm) less than the anatomical dead space volume. The efficiency of gas mixing in the model was assessed by measuring the decay of carbon dioxide concentration in the sphere during high-frequency mechanical ventilation. The experimental results were then compared with those obtained from simulations on a theoretical model based on a diffusional resistance concept which could take account of either turbulent, steady laminar or oscillatory laminar dispersion coefficients. Our results showed that the Taylor turbulent dispersion mechanism had a significant effect and could be the principal factor for the efficiency of gas mixing during high-frequency ventilation at small tidal volumes. [ABSTRACT FROM AUTHOR]

Published
1987
Full Text
View/download PDF

24. Is proximal airway pressure a good reflection of peripheral airspace pressure in infants and children models under HFJV?

Author

Cros, A., Kays, C., Ravussin, P., and Guenard, H.

Abstract

Abstract: This expriimental study was carried out to determine if an alveolar positive end-expiratory pressure (PEEP) could occur during high frequency jet ventilation (HFJV) in infants, and if tracheal pressure is a good estimation of alveolar pressure. We used physical models simulating a 1.5 kg premature (P), a 3 kg newborn (N) and a 6 kg child (C) with normal compliance and normal resistance. Moreover, in the N model, we used two different resistances and lung compliance heterogeneity was studied in the P model. Pressure was measured simultaneously in the tube simulating trachea (Paw) and in the bottle simulating the lung (Palv). HFJV was performed either via an endotracheal tube (ETT) or via a long catheter as in laryngoscopy. The ratio of injection time upon cycle duration (Ti/Ttot) was 20% or 30%, jet frequency was altered from 150 to 300 min−1 and the driving pressure was set as in clinical practice (0.5 and 0.6 bar). PEEP occurred mainly in N (1.1 to 3.2 cm H2O) and C models (0 to 3.5 cm H2O). It was inversely related to expiratory time (Te). The end-expiratory pressure drop between Palv and Paw (ΔEEP) was higher in N and increased from 0.5 to 2 cm H2O with the shortening of Te and with airway resistances, i.e. the presence of ETT. In the heterogeneous model, PEEP and ΔEEP were greater in the higher compliance alveolus. This study shows that the end-expiratory Palv is underestimated by end-expiratory Paw. This is particularly important in the presence of an heterogeneity of distribution in lung compliance. In this case the airway PEEP overestimates the PEEP in the lower compliance alveolus and underestimates the PEEP in the higher compliance alveolus.

Published
1995
Full Text
View/download PDF

25. 46th Medical Maghrebian Congress. November 9-10, 2018. Tunis

Author

Alami Aroussi, A., Fouad, A., Omrane, A., Razzak, A., Aissa, A., Akkad, A., Amraoui, A., Aouam, A., Arfaoui, A., Belkouchi, A., Ben Chaaben, A., Ben Cheikh, A., Ben Khélifa, A., Ben Mabrouk, A., Benhima, A., Bezza, A., Bezzine, A., Bourrahouat, A., Chaieb, A., Chakib, A., Chetoui, A., Daoudi, A., Ech-Chenbouli, A., Gaaliche, A., Hassani, A., Kassimi, A., Khachane, A., Labidi, A., Lalaoui, A., Masrar, A., Mchachi, A., Nakhli, A., Ouakaa, A., Siati, A., Toumi, A., Zaouali, A., Condé, A. Y., Haggui, A., Belaguid, A., abdelkader jalil el hangouche, Gharbi, A., Mahfoudh, A., Bouzouita, A., Aissaoui, A., Ben Hamouda, A., Hedhli, A., Ammous, A., Bahlous, A., Ben Halima, A., Belhadj, A., Blel, A., Brahem, A., Banasr, A., Meherzi, A., Saadi, A., Sellami, A., Turki, A., Ben Miled, A., Ben Slama, A., Daib, A., Zommiti, A., Chadly, A., Jmaa, A., Mtiraoui, A., Ksentini, A., Methnani, A., Zehani, A., Kessantini, A., Farah, A., Mankai, A., Mellouli, A., Touil, A., Hssine, A., Ben Safta, A., Derouiche, A., Jmal, A., Ferjani, A., Djobbi, A., Dridi, A., Aridhi, A., Bahdoudi, A., Ben Amara, A., Benzarti, A., Ben Slama, A. Y., Oueslati, A., Soltani, A., Chadli, A., Aloui, A., Belghuith Sriha, A., Bouden, A., Laabidi, A., Mensi, A., Sabbek, A., Zribi, A., Green, A., Ben Nasr, A., Azaiez, A., Yeades, A., Belhaj, A., Mediouni, A., Sammoud, A., Slim, A., Amine, B., Chelly, B., Jatik, B., Lmimouni, B., Daouahi, B., Ben Khelifa, B., Louzir, B., Dorra, A., Dhahri, B., Ben Nasrallah, C., Chefchaouni, C., Konzi, C., Loussaief, C., Makni, C., Dziri, C., Bouguerra, C., Kays, C., Zedini, C., Dhouha, C., Mohamed, C., Aichaouia, C., Dhieb, C., Fofana, D., Gargouri, D., Chebil, D., Issaoui, D., Gouiaa, D., Brahim, D., Essid, D., Jarraya, D., Trad, D., Ben Hmida, E., Sboui, E., Ben Brahim, E., Baati, E., Talbi, E., Chaari, E., Hammami, E., Ghazouani, E., Ayari, F., Ben Hariz, F., Bennaoui, F., Chebbi, F., Chigr, F., Guemira, F., Harrar, F., Benmoula, F. Z., Ouali, F. Z., Maoulainine, F. M. R., Bouden, F., Fdhila, F., Améziani, F., Bouhaouala, F., Charfi, F., Chermiti Ben Abdallah, F., Hammemi, F., Jarraya, F., Khanchel, F., Ourda, F., Sellami, F., Trabelsi, F., Yangui, F., Fekih Romdhane, F., Mellouli, F., Nacef Jomli, F., Mghaieth, F., Draiss, G., Elamine, G., Kablouti, G., Touzani, G., Manzeki, G. B., Garali, G., Drissi, G., Besbes, G., Abaza, H., Azzouz, H., Said Latiri, H., Rejeb, H., Ben Ammar, H., Ben Brahim, H., Ben Jeddi, H., Ben Mahjouba, H., Besbes, H., Dabbebi, H., Douik, H., El Haoury, H., Elannaz, H., Elloumi, H., Hachim, H., Iraqi, H., Kalboussi, H., Khadhraoui, H., Khouni, H., Mamad, H., Metjaouel, H., Naoui, H., Zargouni, H., Elmalki, H. O., Feki, H., Haouala, H., Jaafoura, H., Drissa, H., Mizouni, H., Kamoun, H., Ouerda, H., Zaibi, H., Chiha, H., Saibi, H., Skhiri, H., Boussaffa, H., Majed, H., Blibech, H., Daami, H., Harzallah, H., Rkain, H., Ben Massoud, H., Jaziri, H., Ben Said, H., Ayed, H., Harrabi, H., Chaabouni, H., Ladida Debbache, H., Harbi, H., Yacoub, H., Abroug, H., Ghali, H., Kchir, H., Msaad, H., Manai, H., Riahi, H., Bousselmi, H., Limem, H., Aouina, H., Jerraya, H., Ben Ayed, H., Chahed, H., Snéne, H., Lahlou Amine, I., Nouiser, I., Ait Sab, I., Chelly, I., Elboukhani, I., Ghanmi, I., Kallala, I., Kooli, I., Bouasker, I., Fetni, I., Bachouch, I., Bouguecha, I., Chaabani, I., Gazzeh, I., Samaali, I., Youssef, I., Zemni, I., Bachouche, I., Bouannene, I., Kasraoui, I., Laouini, I., Mahjoubi, I., Maoudoud, I., Riahi, I., Selmi, I., Tka, I., Hadj Khalifa, I., Mejri, I., Béjia, I., Bellagha, J., Boubaker, J., Daghfous, J., Dammak, J., Hleli, J., Ben Amar, J., Jedidi, J., Marrakchi, J., Kaoutar, K., Arjouni, K., Ben Helel, K., Benouhoud, K., Rjeb, K., Imene, K., Samoud, K., El Jeri, K., Abid, K., Chaker, K., Bouzghaîa, K., Kamoun, K., Zitouna, K., Oughlani, K., Lassoued, K., Letaif, K., Hakim, K., Cherif Alami, L., Benhmidoune, L., Boumhil, L., Bouzgarrou, L., Dhidah, L., Ifrine, L., Kallel, L., Merzougui, L., Errguig, L., Mouelhi, L., Sahli, L., Maoua, M., Rejeb, M., Ben Rejeb, M., Bouchrik, M., Bouhoula, M., Bourrous, M., Bouskraoui, M., El Belhadji, M., Essakhi, M., Essid, M., Gharbaoui, M., Haboub, M., Iken, M., Krifa, M., Lagrine, M., Leboyer, M., Najimi, M., Rahoui, M., Sabbah, M., Sbihi, M., Zouine, M., Chefchaouni, M. C., Gharbi, M. H., El Fakiri, M. M., Tagajdid, M. R., Shimi, M., Touaibia, M., Jguirim, M., Barsaoui, M., Belghith, M., Ben Jmaa, M., Koubaa, M., Tbini, M., Boughdir, M., Ben Salah, M., Ben Fraj, M., Ben Halima, M., Ben Khalifa, M., Bousleh, M., Limam, M., Mabrouk, M., Mallouli, M., Rebeii, M., Ayari, M., Belhadj, M., Ben Hmida, M., Boughattas, M., Drissa, M., El Ghardallou, M., Fejjeri, M., Hamza, M., Jaidane, M., Jrad, M., Kacem, M., Mersni, M., Mjid, M., Serghini, M., Triki, M., Ben Abbes, M., Boussaid, M., Gharbi, M., Hafi, M., Slama, M., Trigui, M., Taoueb, M., Chakroun, M., Ben Cheikh, M., Chebbi, M., Hadj Taieb, M., Ben Khelil, M., Hammami, M., Khalfallah, M., Ksiaa, M., Mechri, M., Mrad, M., Sboui, M., Bani, M., Hajri, M., Mellouli, M., Allouche, M., Mesrati, M. A., Mseddi, M. A., Amri, M., Bejaoui, M., Bellali, M., Ben Amor, M., Ben Dhieb, M., Ben Moussa, M., Chebil, M., Cherif, M., Fourati, M., Kahloul, M., Khaled, M., Machghoul, M., Mansour, M., Abdesslem, M. M., Ben Chehida, M. A., Chaouch, M. A., Essid, M. A., Meddeb, M. A., Gharbi, M. C., Elleuch, M. H., Loueslati, M. H., Sboui, M. M., Mhiri, M. N., Kilani, M. O., Ben Slama, M. R., Charfi, M. R., Nakhli, M. S., Mourali, M. S., El Asli, M. S., Lamouchi, M. T., Cherti, M., Khadhraoui, M., Bibi, M., Hamdoun, M., Kassis, M., Touzi, M., Ben Khaled, M., Fekih, M., Khemiri, M., Ouederni, M., Hchicha, M., Ben Attia, M., Yahyaoui, M., Ben Azaiez, M., Bousnina, M., Ben Jemaa, M., Ben Yahia, M., Daghfous, M., Haj Slimen, M., Assidi, M., Belhadj, N., Ben Mustapha, N., El Idrissislitine, N., Hikki, N., Kchir, N., Mars, N., Meddeb, N., Ouni, N., Rada, N., Rezg, N., Trabelsi, N., Bouafia, N., Haloui, N., Benfenatki, N., Bergaoui, N., Yomn, N., Maamouri, N., Mehiri, N., Siala, N., Beltaief, N., Aridhi, N., Sidaoui, N., Walid, N., Mechergui, N., Mnif, N., Ben Chekaya, N., Bellil, N., Dhouib, N., Achour, N., Kaabar, N., Mrizak, N., Chaouech, N., Hasni, N., Issaoui, N., Ati, N., Balloumi, N., Haj Salem, N., Ladhari, N., Akif, N., Liani, N., Hajji, N., Trad, N., Elleuch, N., Marzouki, N. E. H., Larbi, N., M Barek, N., Rebai, N., Bibani, N., Ben Salah, N., Belmaachi, O., Elmaalel, O., Jlassi, O., Mihoub, O., Ben Zaid, O., Bouallègue, O., Bousnina, O., Bouyahia, O., El Maalel, O., Fendri, O., Azzabi, O., Borgi, O., Ghdes, O., Ben Rejeb, O., Rachid, R., Abi, R., Bahiri, R., Boulma, R., Elkhayat, R., Habbal, R., Tamouza, R., Jomli, R., Ben Abdallah, R., Smaoui, R., Debbeche, R., Fakhfakh, R., El Kamel, R., Gargouri, R., Jouini, R., Nouira, R., Fessi, R., Bannour, R., Ben Rabeh, R., Kacem, R., Khmakhem, R., Ben Younes, R., Karray, R., Cheikh, R., Ben Malek, R., Ben Slama, R., Kouki, R., Baati, R., Bechraoui, R., Fradi, R., Lahiani, R., Ridha, R., Zainine, R., Kallel, R., Rostom, S., Ben Abdallah, S., Ben Hammamia, S., Benchérifa, S., Benkirane, S., Chatti, S., El Guedri, S., El Oussaoui, S., Elkochri, S., Elmoussaoui, S., Enbili, S., Gara, S., Haouet, S., Khammeri, S., Khefecha, S., Khtrouche, S., Macheghoul, S., Mallouli, S., Rharrit, S., Skouri, S., Helali, S., Boulehmi, S., Abid, S., Naouar, S., Zelfani, S., Ben Amar, S., Ajmi, S., Braiek, S., Yahiaoui, S., Ghezaiel, S., Ben Toumia, S., Thabeti, S., Daboussi, S., Ben Abderahman, S., Rhaiem, S., Ben Rhouma, S., Rekaya, S., Haddad, S., Kammoun, S., Merai, S., Mhamdi, S., Ben Ali, R., Gaaloul, S., Ouali, S., Taleb, S., Zrour, S., Hamdi, S., Zaghdoudi, S., Ammari, S., Ben Abderrahim, S., Karaa, S., Maazaoui, S., Saidani, S., Stambouli, S., Mokadem, S., Boudiche, S., Zaghbib, S., Ayedi, S., Jardek, S., Bouselmi, S., Chtourou, S., Manoubi, S., Bahri, S., Halioui, S., Jrad, S., Mazigh, S., Ouerghi, S., Toujani, S., Fenniche, S., Aboudrar, S., Meriem Amari, S., Karouia, S., Bourgou, S., Halayem, S., Rammeh, S., Yaïch, S., Ben Nasrallah, S., Chouchane, S., Ftini, S., Makni, S., Miri, S., Saadi, S., Manoubi, S. A., Khalfallah, T., Mechergui, T., Dakka, T., Barhoumi, T., M Rad, T. E. B., Ajmi, T., Dorra, T., Ouali, U., Hannachi, W., Ferjaoui, W., Aissi, W., Dahmani, W., Dhouib, W., Koubaa, W., Zhir, W., Gheriani, W., Arfa, W., Dougaz, W., Sahnoun, W., Naija, W., Sami, Y., Bouteraa, Y., Elhamdaoui, Y., Hama, Y., Ouahchi, Y., Guebsi, Y., Nouira, Y., Daly, Y., Mahjoubi, Y., Mejdoub, Y., Mosbahi, Y., Said, Y., Zaimi, Y., Zgueb, Y., Dridi, Y., Mesbahi, Y., Gharbi, Y., Hellal, Y., Hechmi, Z., Zid, Z., Elmouatassim, Z., Ghorbel, Z., Habbadi, Z., Marrakchi, Z., Hidouri, Z., Abbes, Z., Ouhachi, Z., Khessairi, Z., Khlayfia, Z., Mahjoubi, Z., and Moatemri, Z.

28. A review of applications of recombinant DNA techniques in diagnosis and treatment of dental diseases.

Author

Kerns, D G, Kerns, L L, and Kays, C R

Abstract

The goal of regeneration in oral maxillofacial reconstruction is replacing the previous goal of repair. Many advances in treatment and diagnosis have taken place in medicine and dentistry with the advent of DNA technology. The purpose of this paper is to provide the dental practitioner an overview of some of the medical research using recombinant DNA technology and its potential use in dentistry.

Published
1996

29. Effect of changing the gravity vector on respiratory output and control

Author

Raffaele Dellaca, P. Vaida, Pierre Techoueyres, D. Bettinelli, Jean-Luc Lachaud, Giuseppe Miserocchi, C. Kays, Dellaca, R, Bettinelli, D, Kays, C, Techoueyres, P, Lachaud, J, Vaida, P, and Miserocchi, G

Subjects
Adult, Male, Gravity (chemistry), respiratory mechanic, Physiology, Acceleration, Posture, Hypergravity, Physiology (medical), Physical Stimulation, Homeostasis, Humans, Respiratory system, Physics, Gravity, Altered, Mathematical analysis, Middle Aged, Adaptation, Physiological, microgravity, Anesthesia, Respiratory Mechanics, pulmonary ventilation, Respiratory control, Female, respiratory control, Hypogravity
Abstract

We studied the respiratory output in five subjects exposed to parabolic flights [gravity vector 1, 1.8 and 0 gravity vector in the craniocaudal direction (Gz)] and when switching from sitting to supine (legs bent at the knees). Despite differences in total respiratory compliance (highest at 0 Gz and in supine and minimum at 1.8 Gz), no significant changes in elastic inspiratory work were observed in the various conditions, except when comparing 1.8 Gz with 1 Gz (subjects were in the seated position in all circumstances), although the elastic work had an inverse relationship with total respiratory compliance that was highest at 0 Gz and in supine posture and minimum at 1.8 Gz. Relative to 1 Gz, lung resistance (airways plus lung tissue) increased significantly by 52% in the supine but slightly decreased at 0 Gz. We calculated, for each condition, the tidal volume changes based on the energy available in the preceding phase and concluded that an increase in inspiratory muscle output occurs when respiratory load increases (e.g., going from 0 to 1.8 Gz), whereas a decrease occurs in the opposite case (e.g., from 1.8 to 0 Gz). Despite these immediate changes, ventilation increased, going to 1.8 and 0 Gz (up to ≈23%), reflecting an increase in mean inspiratory flow rate, tidal volume, and respiratory frequency, while ventilation decreased (approximately −14%), shifting to supine posture (transition time ∼15 s). These data suggest a remarkable feature in the mechanical arrangement of the respiratory system such that it can maintain the ventilatory output with small changes in inspiratory muscle work in face of considerable changes in configuration and mechanical properties.

Published
2004

30. Effect of gravity and posture on lung mechanics

Author

D. Bettinelli, André Capderou, P. Vaida, Giuseppe Miserocchi, Pierre Techoueyres, O. Bailliart, Jean-Luc Lachaud, C. Kays, Bettinelli, D, Kays, C, Bailliart, O, Capderou, A, Techoueyres, P, Lachaud, J, Vaida, P, and Miserocchi, G

Subjects
Adult, Male, Gravity (chemistry), Aircraft, Functional Residual Capacity, Physiology, Recoil pressure, Posture, interstitial pressure, Pulmonary compliance, Functional residual capacity, Esophagus, Physiology (medical), Diffusing capacity, Pressure, Medicine, Humans, Thoracic Wall, Lung Compliance, Body posture, Weightlessness, business.industry, Lung mechanics, Anatomy, Mechanics, respiratory system, Middle Aged, Respiratory Mechanics, esophageal pressure, Female, business
Abstract

The volume-pressure relationship of the lung was studied in six subjects on changing the gravity vector during parabolic flights and body posture. Lung recoil pressure decreased by ∼2.7 cmH2O going from 1 to 0 vertical acceleration (Gz), whereas it increased by ∼3.5 cmH2O in 30° tilted head-up and supine postures. No substantial change was found going from 1 to 1.8 Gz. Matching the changes in volume-pressure relationships of the lung and chest wall (previous data), results in a decrease in functional respiratory capacity of ∼580 ml at 0 Gz relative to 1 Gz and of ∼1,200 ml going to supine posture. Microgravity causes a decrease in lung and chest wall recoil pressures as it removes most of the distortion of lung parenchyma and thorax induced by changing gravity field and/or posture. Hypergravity does not greatly affect respiratory mechanics, suggesting that mechanical distortion is close to maximum already at 1 Gz. The end-expiratory volume during quiet breathing corresponds to the mechanical functional residual capacity in each condition.

Published
2002

31. Effect of gravity on chest wall mechanics

Author

O. Bailliart, Giuseppe Miserocchi, P. Vaida, D. Bettinelli, C. Kays, Pierre Techoueyres, Jean-Luc Lachaud, André Capderou, Bettinelli, D, Kays, C, Bailliart, O, Capderou, A, Techoueyres, P, Lachaud, J, Vaida, P, and Miserocchi, G

Subjects
Thorax, Male, medicine.medical_specialty, Gravity (chemistry), Physiology, Vital Capacity, Respiratory physiology, Chest wall mechanics, Physiology (medical), Internal medicine, medicine, Pressure, Humans, Lung volumes, Lung, Physics, Weightlessness, Total Lung Capacity, chest wall resting volume, Middle Aged, chest wall compliance, Surgery, Compliance (physiology), Residual Volume, Volume (thermodynamics), Inhalation, Cardiology, Respiratory Mechanics, esophageal pressure, Female, Lung Volume Measurements, supine posture, Compliance, Gravitation
Abstract

Chest wall mechanics was studied in four subjects on changing gravity in the craniocaudal direction (Gz) during parabolic flights. The thorax appears very compliant at 0 Gz: its recoil changes only from −2 to 2 cmH2O in the volume range of 30–70% vital capacity (VC). Increasing Gz from 0 to 1 and 1.8 Gzprogressively shifted the volume-pressure curve of the chest wall to the left and also caused a fivefold exponential decrease in compliance. For lung volume z than from 1 to 1.8 Gz. For a volume from 30 to 70% VC, the effect is inspiratory going from 0 to 1 Gz but expiratory from 1 to 1.8 Gz. For a volume greater than ∼70% VC, gravity always has an expiratory effect. The data suggest that the chest wall does not behave as a linear system when exposed to changing gravity, as the effect depends on both chest wall volume and magnitude of Gz.

Published
2002

32. Erectile function outcomes following surgical treatment of ischemic priapism.

Author

Rahoui M, Ouanes Y, Kays C, Mokhtar B, Mrad Dali K, Sellami A, Ben Rhouma S, and Nouira Y

Abstract

Introduction: Ischemic Priapism is defined as an abnormally prolonged state of erection, exceeding 6 h, often and irreducible, occurring without any sexual stimulation. Ischemic priapism has a fatal consequence on the sexual function of men if it's not promptly managed. This pathology can cause erectile dysfunction and this can alter the quality of life of patients., Objective: The aim of our study was to determine the factors influencing erectile function after treatment of ischemic priapism., Patients and Methods: This is a ten-year retrospective, descriptive and analytic study of 40 patients who consulted the urology department at the university hospital center for treatment of ischemic priapism (2010-2019)., Results: We included 40 patients in our study. The mean age was 35.2 [18-62]. Duration of priapism varied from 20 to 360 h (mean 76.6). The most common etiology of priapism was sickle cell disease in 65% of cases. The mean preoperative IIEF-5 score was 23 [21-26]. All patients underwent corporal aspiration with an injection of ephedrine, but detumescence was observed in only 10% of cases. Thirty-six patients had a distal shunt with detumescence in approximately 70% of cases. Eleven patients underwent a distal shunt but seven patients had definitive fibrosis. After the episode of priapism, only eight patients retained normal erectile function. The mean postoperative IIEF-5 score was 14 [ 7-26]. We noted an improvement in erectile function in 8 patients treated with tadalafil. In multivariate analysis, we have demonstrated that a treatment delay exceeding 48 h, fibrosis and the necessity of a distal shunt significantly affects postoperative erectile function (p = 0.001; p = 0.002; p = 0.002 respectively)., Conclusion: According to our study, delayed management exceeding 48 h, fibrosis and the necessity of a surgical distal shunt are three independent factors affecting erectile function after treatment of ischemic priapism., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors.)

Published
2022
Full Text
View/download PDF

33. Double retroperitoneal hydatid localization: About a case report.

Author

Mejri R, Kays C, Mokhtar B, Ben Rhouma S, and Nouira Y

Abstract

The hydatid cyst is a parasitic pathology which is endemic in Tunisia and presents a public health problem.Hydatid cysts located in the retroperitoneum, especially around or in the kidney, are rare and only represent 5% of visceral locations. The kidney is the most commonly affected organ of the urinary tract.The psoas muscle is an uncommon location and not less than 70 cases have been cited. We report the Case of an unusual presentation of a right kidney hydatid cyst associated with a psoas muscle location. To our knowledge, this association of double retroperitoneal location has not been reported in the literature., Competing Interests: The authors declare that there are no conflicts of interest regarding the publication of this article., (© 2021 Published by Elsevier Inc.)

Published
2021
Full Text
View/download PDF

34. 46th Medical Maghrebian Congress. November 9-10, 2018. Tunis.

Author

Alami Aroussi A, Fouad A, Omrane A, Razzak A, Aissa A, Akkad A, Amraoui A, Aouam A, Arfaoui A, Belkouchi A, Ben Chaaben A, Ben Cheikh A, Ben Khélifa A, Ben Mabrouk A, Benhima A, Bezza A, Bezzine A, Bourrahouat A, Chaieb A, Chakib A, Chetoui A, Daoudi A, Ech-Chenbouli A, Gaaliche A, Hassani A, Kassimi A, Khachane A, Labidi A, Lalaoui A, Masrar A, McHachi A, Nakhli A, Ouakaa A, Siati A, Toumi A, Zaouali A, Condé AY, Haggui A, Belaguid A, El Hangouche AJ, Gharbi A, Mahfoudh A, Bouzouita A, Aissaoui A, Ben Hamouda A, Hedhli A, Ammous A, Bahlous A, Ben Halima A, Belhadj A, Bezzine A, Blel A, Brahem A, Banasr A, Meherzi A, Saadi A, Sellami A, Turki A, Ben Miled A, Ben Slama A, Daib A, Zommiti A, Chadly A, Jmaa A, Mtiraoui A, Ksentini A, Methnani A, Zehani A, Kessantini A, Farah A, Mankai A, Mellouli A, Zaouali A, Touil A, Hssine A, Ben Safta A, Derouiche A, Jmal A, Ferjani A, Djobbi A, Dridi A, Aridhi A, Bahdoudi A, Ben Amara A, Benzarti A, Ben Slama AY, Oueslati A, Soltani A, Chadli A, Aloui A, Belghuith Sriha A, Bouden A, Laabidi A, Mensi A, Ouakaa A, Sabbek A, Zribi A, Green A, Ben Nasr A, Azaiez A, Yeades A, Belhaj A, Mediouni A, Sammoud A, Slim A, Amine B, Chelly B, Jatik B, Lmimouni B, Daouahi B, Ben Khelifa B, Louzir B, Dorra A, Dhahri B, Ben Nasrallah C, Chefchaouni C, Konzi C, Loussaief C, Makni C, Dziri C, Bouguerra C, Kays C, Zedini C, Dhouha C, Mohamed C, Aichaouia C, Dhieb C, Fofana D, Gargouri D, Chebil D, Issaoui D, Gouiaa D, Brahim D, Essid D, Jarraya D, Trad D, Ben Hmida E, Sboui E, Ben Brahim E, Baati E, Talbi E, Chaari E, Hammami E, Ghazouani E, Ayari F, Ben Hariz F, Bennaoui F, Chebbi F, Chigr F, Guemira F, Harrar F, Benmoula FZ, Ouali FZ, Maoulainine FMR, Bouden F, Fdhila F, Améziani F, Bouhaouala F, Charfi F, Chermiti Ben Abdallah F, Hammemi F, Jarraya F, Khanchel F, Ourda F, Sellami F, Trabelsi F, Yangui F, Fekih Romdhane F, Mellouli F, Nacef Jomli F, Mghaieth F, Draiss G, Elamine G, Kablouti G, Touzani G, Manzeki GB, Garali G, Drissi G, Besbes G, Abaza H, Azzouz H, Said Latiri H, Rejeb H, Ben Ammar H, Ben Brahim H, Ben Jeddi H, Ben Mahjouba H, Besbes H, Dabbebi H, Douik H, El Haoury H, Elannaz H, Elloumi H, Hachim H, Iraqi H, Kalboussi H, Khadhraoui H, Khouni H, Mamad H, Metjaouel H, Naoui H, Zargouni H, Elmalki HO, Feki H, Haouala H, Jaafoura H, Drissa H, Mizouni H, Kamoun H, Ouerda H, Zaibi H, Chiha H, Kamoun H, Saibi H, Skhiri H, Boussaffa H, Majed H, Blibech H, Daami H, Harzallah H, Rkain H, Ben Massoud H, Jaziri H, Ben Said H, Ayed H, Harrabi H, Chaabouni H, Ladida Debbache H, Harbi H, Yacoub H, Abroug H, Ghali H, Kchir H, Msaad H, Ghali H, Manai H, Riahi H, Bousselmi H, Limem H, Aouina H, Jerraya H, Ben Ayed H, Chahed H, Snéne H, Lahlou Amine I, Nouiser I, Ait Sab I, Chelly I, Elboukhani I, Ghanmi I, Kallala I, Kooli I, Bouasker I, Fetni I, Bachouch I, Bouguecha I, Chaabani I, Gazzeh I, Samaali I, Youssef I, Zemni I, Bachouche I, Youssef I, Bouannene I, Kasraoui I, Laouini I, Mahjoubi I, Maoudoud I, Riahi I, Selmi I, Tka I, Hadj Khalifa I, Mejri I, Béjia I, Bellagha J, Boubaker J, Daghfous J, Dammak J, Hleli J, Ben Amar J, Jedidi J, Marrakchi J, Kaoutar K, Arjouni K, Ben Helel K, Benouhoud K, Rjeb K, Imene K, Samoud K, El Jeri K, Abid K, Chaker K, Abid K, Bouzghaîa K, Kamoun K, Zitouna K, Oughlani K, Lassoued K, Letaif K, Hakim K, Cherif Alami L, Benhmidoune L, Boumhil L, Bouzgarrou L, Dhidah L, Ifrine L, Kallel L, Merzougui L, Errguig L, Mouelhi L, Sahli L, Maoua M, Rejeb M, Ben Rejeb M, Bouchrik M, Bouhoula M, Bourrous M, Bouskraoui M, El Belhadji M, El Belhadji M, Essakhi M, Essid M, Gharbaoui M, Haboub M, Iken M, Krifa M, Lagrine M, Leboyer M, Najimi M, Rahoui M, Sabbah M, Sbihi M, Zouine M, Chefchaouni MC, Gharbi MH, El Fakiri MM, Tagajdid MR, Shimi M, Touaibia M, Jguirim M, Barsaoui M, Belghith M, Ben Jmaa M, Koubaa M, Tbini M, Boughdir M, Ben Salah M, Ben Fraj M, Ben Halima M, Ben Khalifa M, Bousleh M, Limam M, Mabrouk M, Mallouli M, Rebeii M, Ayari M, Belhadj M, Ben Hmida M, Boughattas M, Drissa M, El Ghardallou M, Fejjeri M, Hamza M, Jaidane M, Jrad M, Kacem M, Mersni M, Mjid M, Sabbah M, Serghini M, Triki M, Ben Abbes M, Boussaid M, Gharbi M, Hafi M, Slama M, Trigui M, Taoueb M, Chakroun M, Ben Cheikh M, Chebbi M, Hadj Taieb M, Kacem M, Ben Khelil M, Hammami M, Khalfallah M, Ksiaa M, Mechri M, Mrad M, Sboui M, Bani M, Hajri M, Mellouli M, Allouche M, Mesrati MA, Mseddi MA, Amri M, Bejaoui M, Bellali M, Ben Amor M, Ben Dhieb M, Ben Moussa M, Chebil M, Cherif M, Fourati M, Kahloul M, Khaled M, Machghoul M, Mansour M, Abdesslem MM, Ben Chehida MA, Chaouch MA, Essid MA, Meddeb MA, Gharbi MC, Elleuch MH, Loueslati MH, Sboui MM, Mhiri MN, Kilani MO, Ben Slama MR, Charfi MR, Nakhli MS, Mourali MS, El Asli MS, Lamouchi MT, Cherti M, Khadhraoui M, Bibi M, Hamdoun M, Kassis M, Touzi M, Ben Khaled M, Fekih M, Khemiri M, Ouederni M, Hchicha M, Kassis M, Ben Attia M, Yahyaoui M, Ben Azaiez M, Bousnina M, Ben Jemaa M, Ben Yahia M, Daghfous M, Haj Slimen M, Assidi M, Belhadj N, Ben Mustapha N, El Idrissislitine N, Hikki N, Kchir N, Mars N, Meddeb N, Ouni N, Rada N, Rezg N, Trabelsi N, Bouafia N, Haloui N, Benfenatki N, Bergaoui N, Yomn N, Ben Mustapha N, Maamouri N, Mehiri N, Siala N, Beltaief N, Aridhi N, Sidaoui N, Walid N, Mechergui N, Mnif N, Ben Chekaya N, Bellil N, Dhouib N, Achour N, Kaabar N, Mrizak N, Mnif N, Chaouech N, Hasni N, Issaoui N, Ati N, Balloumi N, Haj Salem N, Ladhari N, Akif N, Liani N, Hajji N, Trad N, Elleuch N, Marzouki NEH, Larbi N, M'barek N, Rebai N, Bibani N, Ben Salah N, Belmaachi O, Elmaalel O, Jlassi O, Mihoub O, Ben Zaid O, Bouallègue O, Bousnina O, Bouyahia O, El Maalel O, Fendri O, Azzabi O, Borgi O, Ghdes O, Ben Rejeb O, Rachid R, Abi R, Bahiri R, Boulma R, Elkhayat R, Habbal R, Rachid R, Tamouza R, Jomli R, Ben Abdallah R, Smaoui R, Debbeche R, Fakhfakh R, El Kamel R, Gargouri R, Jouini R, Nouira R, Fessi R, Bannour R, Ben Rabeh R, Kacem R, Khmakhem R, Ben Younes R, Karray R, Cheikh R, Ben Malek R, Ben Slama R, Kouki R, Baati R, Bechraoui R, Fakhfakh R, Fradi R, Lahiani R, Ridha R, Zainine R, Kallel R, Rostom S, Ben Abdallah S, Ben Hammamia S, Benchérifa S, Benkirane S, Chatti S, El Guedri S, El Oussaoui S, Elkochri S, Elmoussaoui S, Enbili S, Gara S, Haouet S, Khammeri S, Khefecha S, Khtrouche S, Macheghoul S, Mallouli S, Rharrit S, Skouri S, Helali S, Boulehmi S, Abid S, Naouar S, Zelfani S, Ben Amar S, Ajmi S, Braiek S, Yahiaoui S, Ghezaiel S, Ben Toumia S, Thabeti S, Daboussi S, Ben Abderahman S, Rhaiem S, Ben Rhouma S, Rekaya S, Haddad S, Kammoun S, Merai S, Mhamdi S, Ben Ali R, Gaaloul S, Ouali S, Taleb S, Zrour S, Hamdi S, Zaghdoudi S, Ammari S, Ben Abderrahim S, Karaa S, Maazaoui S, Saidani S, Stambouli S, Mokadem S, Boudiche S, Zaghbib S, Ayedi S, Jardek S, Bouselmi S, Chtourou S, Manoubi S, Bahri S, Halioui S, Jrad S, Mazigh S, Ouerghi S, Toujani S, Fenniche S, Aboudrar S, Meriem Amari S, Karouia S, Bourgou S, Halayem S, Rammeh S, Yaïch S, Ben Nasrallah S, Chouchane S, Ftini S, Makni S, Manoubi S, Miri S, Saadi S, Manoubi SA, Khalfallah T, Mechergui T, Dakka T, Barhoumi T, M'rad TEB, Ajmi T, Dorra T, Ouali U, Hannachi W, Ferjaoui W, Aissi W, Dahmani W, Dhouib W, Koubaa W, Zhir W, Gheriani W, Arfa W, Dougaz W, Sahnoun W, Naija W, Sami Y, Bouteraa Y, Elhamdaoui Y, Hama Y, Ouahchi Y, Guebsi Y, Nouira Y, Daly Y, Mahjoubi Y, Mejdoub Y, Mosbahi Y, Said Y, Zaimi Y, Zgueb Y, Dridi Y, Mesbahi Y, Gharbi Y, Hellal Y, Hechmi Z, Zid Z, Elmouatassim Z, Ghorbel Z, Habbadi Z, Marrakchi Z, Hidouri Z, Abbes Z, Ouhachi Z, Khessairi Z, Khlayfia Z, Mahjoubi Z, and Moatemri Z

Subjects
Africa, Northern epidemiology, Anatomy education, Education, Medical history, Education, Medical methods, Education, Medical organization & administration, History, 21st Century, Humans, Internship and Residency standards, Internship and Residency trends, Job Satisfaction, Pathology, Clinical education, Tunisia epidemiology, Education, Medical trends, Medicine methods, Medicine organization & administration, Medicine trends
Published
2019

35. In vivo estimates of NO and CO conductance for haemoglobin and for lung transfer in humans.

Author

Guénard HJ, Martinot JB, Martin S, Maury B, Lalande S, and Kays C

Subjects
Adult, Aged, Capillaries metabolism, Carbon Monoxide blood, Female, Humans, Linear Models, Lung blood supply, Male, Middle Aged, Nitric Oxide blood, Oxygen metabolism, Pressure, Pulmonary Diffusing Capacity, Young Adult, Carbon Monoxide metabolism, Hemoglobins metabolism, Lung metabolism, Models, Cardiovascular, Nitric Oxide metabolism, Pulmonary Gas Exchange
Abstract

Membrane conductance (Dm) and capillary lung volume (Vc) derived from NO and CO lung transfer measurements in humans depend on the blood conductance (θ) values of both gases. Many θ values have been proposed in the literature. In the present study, measurements of CO and NO transfer while breathing 15% or 21% O2 allowed the estimation of θNO and the calculation of the optimal equation relating 1/θCO to pulmonary capillary oxygen pressure (PcapO2). In 10 healthy subjects, the mean calculated θNO value was similar to the θNO value previously reported in the literature (4.5mmHgmin(-1)) provided that one among three θCO equations from the literature was chosen. Setting 1/θCO=a·PcapO2+b, optimal values of a and b could be chosen using two methods: 1) by minimizing the difference between Dm/Vc ratios for any PcapO2, 2) by establishing a linear equation relating a and b. Using these methods, we are proposing the equation 1/θCO=0.0062·PcapO2+1.16, which is similar to two equations previously reported in the literature. With this set of θ values, DmCO reached the morphometric range., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Published
2016
Full Text
View/download PDF

36. Office cystoscopy and transrectal ultrasound-guided prostate biopsies pose minimal risk: prospective evaluation of 921 procedures.

Author

Matin SF, Feeley T, Kennamer D, Corriere JN Jr, Miles M, Kays C, Green H, Craig CE, and Dinney CP

Subjects
Humans, Male, Office Visits, Prospective Studies, Quality Assurance, Health Care, Risk Factors, Ultrasonography, Biopsy, Needle methods, Cystoscopy, Prostate diagnostic imaging, Prostate pathology
Abstract

Objectives: To examine the outcomes of 2 commonly performed urologic office procedures as a part of a process to align these with the Joint Commission standards to ensure patient safety. We determined whether cystoscopy and transrectal ultrasound-guided prostate biopsy performed in the office setting pose minimal risk to patients., Methods: An evaluation of urologic office procedures in the office clinic setting of an academic medical center was prospectively performed during 3 different periods to document patient and system events. The patients included those undergoing cystoscopy for workup of hematuria, history of bladder cancer, or other indicated conditions (n = 554) and patients undergoing transrectal ultrasound-guided prostate biopsy for suspicion of prostate cancer (n = 367). All consecutive patients were evaluated., Results: A total of 7 patient events (0.76%) and 101 system events (10.97%) were documented. The most significant adverse patient event was 1 case of acute bacterial prostatitis due to quinolone-resistant Escherichia coli. In most cases, the system event rate reflected a delay of >15 minutes in the initiation of the procedure. No patient experienced significant bleeding, perforation, or a major cardiopulmonary event., Conclusions: The results of our study have shown that cystoscopy and transrectal ultrasound-guided prostate biopsy procedures performed in the office setting pose a minimal risk to patients. This information could be useful for hospitals and practices that are undergoing efforts to align their individual policies with current Joint Commission standards.

Published
2009
Full Text
View/download PDF

37. [Anesthesia induction with sevoflurane in adult patients with predictive signs of difficult intubation].

Author

Cros AM, Chopin F, Lopez C, and Kays C

Subjects
Adult, Anesthetics administration & dosage, Female, Fentanyl administration & dosage, Humans, Male, Sevoflurane, Intubation, Intratracheal adverse effects, Methyl Ethers administration & dosage
Abstract

Objective: This work was carried out to study induction with sevoflurane in adult patients with predictive signs of difficult intubation., Study Design: Randomised prospective study., Patients and Methods: The study had two parts. Part I: 15 patients without predictive signs of difficult intubation but with a cervical collar. Eight patients were anaesthetised with propofol 3 mg.kg-1 and fentanyl 2 micrograms.kg-1, seven with sevoflurane 8%. Part II: 20 patients with predictive signs of difficult intubation anaesthetised with sevoflurane 8%., Results: In part I, all patients were intubated, the time for intubation was longer with sevoflurane, 6 vs 4 min. They were apneic only in the propofol group. After intubation, 7 cases of coughing (4 severe) occurred in the propofol group and 3 moderate coughing in the sevoflurane group. In part II, one patient experienced considerable agitation after oral airway insertion and was excluded. Other patients were intubated with sevoflurane. Seven patients were intubated with a bougie, three patients through an intubating LMA and one patient with a rigid bronchoscope. The other patients were intubated with a Macintosh blade. The mean time for intubation was 10 +/- 7 min and end tidal sevoflurane concentration after intubation was 4 +/- 0.6%. After intubation, 7 cases of coughing (3 severe) occurred but no desaturation < 95%. No significant haemodynamic variations occurred., Conclusion: Induction with sevoflurane 8% allowed tracheal intubation without major incidents. All patients breathed spontaneously. Sevoflurane can be recommended for induction in cases of predictive difficult intubation.

Published
2002
Full Text
View/download PDF

38. Changes in lower limb volume in humans during parabolic flight.

Author

Bailliart O, Capderou A, Cholley BP, Kays C, Rivière D, Téchoueyres P, Lachaud JL, and Vaïda P

Subjects
Adult, Aerospace Medicine, Female, Humans, Male, Middle Aged, Plethysmography, Hypergravity, Hypogravity, Leg anatomy & histology, Leg physiology
Abstract

Variations in gravity [head-to-foot acceleration (Gz)] induce hemodynamic alterations as a consequence of changes in hydrostatic pressure gradients. To estimate the contribution of the lower limbs to blood pooling or shifting during the different gravity phases of a parabolic flight, we measured instantaneous thigh and calf girths by using strain-gauge plethysmography in five healthy volunteers. From these circumferential measurements, segmental leg volumes were calculated at 1, 1.7, and 0 Gz. During hypergravity, leg segment volumes increased by 0.9% for the thigh (P < 0.001) and 0.5% for the calf (P < 0.001) relative to 1-Gz conditions. After sudden exposure to microgravity following hypergravity, leg segment volumes were reduced by 3.5% for the thigh (P < 0.001) and 2.5% for the calf (P < 0.001) relative to 1.7-Gz conditions. Changes were more pronounced at the upper part of the leg. Extrapolation to the whole lower limb yielded an estimated 60-ml increase in leg volume at the end of the hypergravity phase and a subsequent 225-ml decrease during microgravity. Although quantitatively less than previous estimations, these blood shifts may participate in the hemodynamic alterations observed during hypergravity and weightlessness.

Published
1998
Full Text
View/download PDF

39. Pulmonary diffusing capacity and pulmonary capillary blood volume during parabolic flights.

Author

Väida P, Kays C, Rivière D, Téchoueyres P, and Lachaud JL

Subjects
Acceleration adverse effects, Adult, Air Pressure, Calibration, Humans, Male, Microcirculation physiology, Middle Aged, Vital Capacity, Weightlessness Simulation, Blood Volume physiology, Pulmonary Circulation physiology, Pulmonary Diffusing Capacity physiology, Weightlessness adverse effects
Abstract

Data from the Spacelab Life Sciences-1 (SLS-1) mission have shown sustained but moderate increase in pulmonary diffusing capacity (DL). Because of the occupational constraints of the mission, data were only obtained after 24 h of exposure to microgravity. Parabolic flights are often used to study some effects of microgravity, and we measured changes in DL occurring at the very onset of weightlessness. Measurements of DL, membrane diffusing capacity, and pulmonary capillary blood volume were made in 10 male subjects during the 20-s 0-G phases of parabolic flights performed by the "zero-G" Caravelle aircraft. Using the standardized single-breath technique, we measured DL for CO and nitric oxide simultaneously. We found significant increases in DL for CO (62%), in membrane diffusing capacity for CO (47%), in DL for nitric oxide (47%), and in pulmonary capillary blood volume (71%). We conclude that major changes in the alveolar membrane gas transfers and in the pulmonary capillary bed occur at the very onset of microgravity. Because these changes are much greater than those reported during sustained microgravity, the effects of rapid transition from hypergravity to microgravity during parabolic flights remain questionable.

Published
1997
Full Text
View/download PDF

41. Laparoscopic excision of a benign gastric tumor.

Author

Clancy TV, Moore PM, Ramshaw DG, and Kays CR

Subjects
Aged, Female, Humans, Laparoscopy, Leiomyoma surgery, Stomach Neoplasms surgery
Abstract

A successful laparoendoscopic excision of a 3-cm leiomyoma of the stomach is reported. Review of related literature and suggested technique and methods for this procedure are described.

Published
1994
Full Text
View/download PDF

42. [Alveolar pressure during forced vital capacity. Method and application (author's transl)].

Author

Kays C, Guénard H, and Choukroun ML

Subjects
Humans, Pressure, Pulmonary Alveoli physiology, Vital Capacity
Abstract

A method allowing the measurement of mean alveolar pressure (Palv) during forced vital capacity is described. The basis of the method is the calculation of the difference between mouth and chest flows, which are measured with a Fleisch pneumotachograph (PTG) and a volumetric plethysmograph respectively. Metrologic conditions of the calculation are discussed. During the forced expiration, the estimation of Palv is realized in good metrological conditions. During inspiration, the thermal condition of the PTG varies and the measured flow is not accurate; thus, the calculated Palv is only an estimation. Some examples of Palv vs mouth flow loops are shown. The simultaneous recordings of this loop and the usual V/V loop allow us to know if a low mouth flow is due to a high pulmonary impedance with high Palv or to a low Palv. For a given impedance, Palv measurement seems to be a good test of the respiratory muscle function.

Published
1982

43. Effect of resident gas density on CO2 elimination during high-frequency oscillation: a model study.

Author

Ben Jebria A and Kays C

Subjects
Carbon Dioxide, Diffusion, Respiration, Tidal Volume, Models, Biological, Pulmonary Gas Exchange
Abstract

In order to throw more light on the mechanisms governing the efficiency of intrapulmonary gas mixing during high-frequency oscillatory ventilation, an experimental, and theoretical, study was carried out on a model casting of the airways of a human lung that closely resembled the respiratory tract. The experiments were carried out under various conditions during high-frequency oscillation (HFO), by using alveolor resident gas mixtures of different densities. The efficiency of gas mixing was assessed by measuring the time constants of the CO2 alveolar washout which were compared to those obtained from simulations on a theoretical model based on a turbulent diffusional resistance concept. Our results showed that the decay in CO2 concentration was highly dependent on both frequency (f) and tidal volume (VT). Tidal volume was found to have a greater effect on efficiency of gas mixing than frequency. Moreover, even though there were statistically significant differences in the time courses of CO2 washout between N2 and He, N2 and SF6 or between He and SF6, this could not imply that gas mixing was limited by diffusion. Agreement between the experimental time constants of CO2 elimination during HFO and the predicted mixing time constants was satisfactory. It is concluded that turbulent augmented diffusion is the main factor responsible for effective gas transport during high-frequency oscillatory ventilation.

Published
1987
Full Text
View/download PDF

44. Effects of water temperature on pulmonary volumes in immersed human subjects.

Author

Choukroun ML, Kays C, and Varène P

Subjects
Adult, Expiratory Reserve Volume, Functional Residual Capacity, Humans, Inspiratory Reserve Volume, Male, Maximal Voluntary Ventilation, Tidal Volume, Vital Capacity, Water, Immersion, Respiration, Temperature
Abstract

Pulmonary volumes and capacities have been measured at three water temperatures (Tw = 25, 34, 40 degrees C) in standing subjects immersed up to the shoulders. The comparison of data obtained in air with those obtained in thermoneutral immersion (Tw = 34 degrees C) confirms the results previously published in several studies. The comparison of data obtained in immersion at different Tw shows: 1. A significant decrease in vital capacity (VC) with bath temperature (VC 40 degrees C greater than VC 34 degrees C greater than VC 25 degrees C). The same decrease is observed in the inspiratory reserve volume (IRV) while the expiratory reserve volume (ERV), the residual volume (RV) and the functional residual capacity (FRC) do not vary. 2. A significant decrease in maximum breathing capacity (MBC) with bath temperature (MBC 40 degrees C greater than MBC 25 degrees C). 3. A significant increase in tidal volume (VT) in cold or hot water compared to thermoneutral water (VT40 degrees C greater than VT34 degrees C; VT34 degrees C less than VT25 degrees C) during quiet breathing. Breathing frequency does not change, thus ventilation (V) follows the same evolution as VT. The relative abdominal (ABD) contribution to VT, estimated by a double belt inductance plethysmograph, is reduced at Tw = 25 degrees C but unchanged at Tw = 40 degrees C compared to thermoneutral bath. Beside variations in the metabolic state, the variations of the pulmonary volumes as a function of Tw are estimated to be mainly due to alterations in respiratory muscles functioning.

Published
1989
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results