Naslov
KEMORECEPTORSKI PRAG ZA NASTUP NEVOLJNIH DIŠNIH POKRETA TIJEKOM MAKSIMALNE APNEJE
(Chemoreceptor threshold for the start of involuntary breathing movements during maximal apnea)

Autori
Mihajlo Lojpur

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, doktorska disertacija

Fakultet
Medicinski fakultet

Mjesto
Split

Datum
15.07

Godina
2013

Stranica
49

Mentor
Prof. dr. Željko Dujić

Ključne riječi
ronjenje na dah; plinovi u arterijskoj krvi; hemodinamika
(Breath holding; arterial blood gases; hemodynamics)

Sažetak
The growing urge to breathe that occurs during breath-holding results in development of involuntary breathing movements (IBMs). The present study determined whether IBMs are initiated at critical levels of hypercapnia and/or hypoxia during maximal apnoea. Arterial blood gasses at the onset of IBM were monitored during maximal voluntary breath-holds. Eleven healthy men performed breath holds after breathing air, hyperoxic–normocapnia, hypoxic–normocapnia, and normoxic–hypercapnia. Prebreathing of the gas mixtures facilitated the IBM onset, reducing the time-to-onset for ~46% (hyperoxic condition) and for ~80% (hypoxic condition) compared to the normoxic air breathing time. A strong correlation (R = 0.83, P = 0.002) between arterial partial pressure of CO2 (PaCO2 ) at IBM onset after pre-breathing hyperoxic and hypercapnic gas mixtures was observed, suggesting the existence of a possible IBM PaCO2 threshold level of ~6.5 ± 0.5 kPa. No clear “threshold” was observed for partial pressure of arterial O2 (PaO2 ). However, we observed that IBM onset was influenced, in part, by an interaction between PaO2 and PaCO2 levels during maximal apnoea. This study demonstrated the complex interaction between arterial blood-gases and the physiological response to maximal breath holding.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

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