Tympanic temperature and heart rate changes in firefighters during treadmill runs performed with different fireproof jackets.

Six well-trained firefighters performed six treadmill runs at 70% of the velocity at VO2max (Maximal aerobic velocity MAV = 13.2+/-0.3 km h(-1)). A recovery time of 1 week was allowed between trials. The first session was performed by subjects wearing only shorts (i.e. no fire jacket, J0). A similar protocol was applied subsequently to test the physiological effects associated with the wearing of one of five different fire jackets: one leather (J1) and four textile-type jackets: VTN with membrane (J2), VTN without membrane (J3), Vidal with Kermel HTA (Haute Teneur en Aramide i.e. high density in Aramide) (J4); and Rolland with Kermel HTA (J5). All sessions were performed in a randomized order and in laboratory conditions. Exercise with the fireproof jackets resulted in higher tympanic temperature (Tty), heart rate (HR) and body mass loss (BML) changes compared to J0 (p<0.001). The magnitudes of these changes depended on the type of the jacket. Exercise in the leather jacket (J1) resulted in the highest Tty and HR, which differed significantly from values in all other conditions (p<0.001). The exercise-induced increases in Tty wearing jackets J3 and J5 were also significantly (p < 0.05) higher than those observed with jackets J2 and J4. In conclusion, textile jackets induced less HR and Tty stresses than the leather one. The magnitude of the physiological responses induced by textile jackets were correlated to jacket weight. J2 and J4 jackets were more effective in limiting hyperthermia and any potential detrimental effect on the exercise capacity.

[Continuous monitoring, in the adult, of arterial oxygen saturation during apnea following intubation]. / Monitorage continu chez l'adulte de la saturation artérielle en oxygène durant l'apnée qui suit l'intubation.

Twenty ASA I or II patients were studied to assess the safety of oxygenation for 4 min prior to intubing, so as to prevent the hypoxaemia related to tracheal intubation. The arterialized capillary blood saturation (Spo2) was continuously monitored with a pulse oximeter Nellcor 100 equipped with a finger probe. Patients spontaneously breathed oxygen (FIO2 = 1) while anaesthesia was induced with pancuronium bromide, thiopentone and fentanyl. Following apnoea, ventilation was manually controlled during 4 min (FIO2 = 1). The values of Spo2 were recorded before induction, at the end of the 4 min oxygenation period and after 5 min of apnoea. An arterial blood sample was withdrawn at the end of apnoea and analysed immediately using an OSM 2b hemoximeter. Apnoea was interrupted in case of desaturation below 95%, new arrhythmia or haemodynamic instability (blood pressure +/- 20% of control value). Mean saturation (+/- SD) before oxygenation was 98.6 +/- 1.35%. After oxygenating for 4 min, all the Spo2 reached 100%. After the 5 min apnoea period, no saturation was below 95% (mean +/- SD = 98.89 +/- 1.66); at this time, Sao2 and Spo2 did not significantly differ (p less than 0.001). In one case, apnoea had to be interrupted, because of the occurrence of arrhythmias, unrelated to a blood gas disorder (PaO2 = 225 mmHg; Paco2 = 34 mmHg; SaO2 = 100%; pH = 7.44). This study confirmed the efficacy and safety of oxygenating for 4 min before intubation.(ABSTRACT TRUNCATED AT 250 WORDS)

[The curve of the intraventricular pressure-volume relationships is not mono-exponential]. / La courbe des relations pression-volume intraventriculaire n'est pas une mono-exponentielle

The graphic and statistic investigations have let us to assert that the right ventricular P/V relationship's curve is characterized by two successive segments: linear and exponential respectively. We have proposed an interpretation based on Roach's and Burton's works. Interest of information about this curve is double: 1) it is a function of the ventricular cavity volume; 2) it gives a general idea about the mode of ventricular filling.

[Tension-volume relationship of the wall of the isolated right ventricle]. / Relations tension-volume de la paroi du ventricule droit isolé

The variations of tension on the wall of the isolated right verticle have been observed on 18 dogs. The Tension/Volume curve we got can be superimposed to that obtained by pressures. The wall of the right ventricle itself (the radius of the curve in the cavity and the wall-thickness) seems to vary only with the changes in its tension in a rather small part of the curve.