Naslov
Comparison between oscillometric and tonometric methods for assessment of hyperoxia-induced increase in arterial stiffness in healthy humans

Autori
Boban, Mladen ; Modun, Darko ; Vuković, Jonatan ; Budimir, Danijela ; Mudnić, Ivana ; Gunjača, Grgo

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Skup
5th International Symposium on Arterial Stiffness

Mjesto i datum
Budimpešta, Mađarska, 20.02.2009. - 21.02.2009

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Oxidative stress; Hyperoxia; Augmentation index; Vascular activity

Sažetak
Oxygen is widely used in the treatment of a diverse range of acute medical conditions. However, it is often administered empirically, without prior knowledge of arterial oxyhemoglobin saturation. As a result, patients may be exposed to significant periods of hyperoxia. Hyperoxia causes vasoconstriction and acutely increases arterial stiffness, as manifested by elevation of augmentation index (AIx), in healthy subjects. We compared two instruments, SphygmoCor (AtCor Medical, Sydney, Australia) and recently validated Arteriograph (TensioMedTM Kft, Budapest, Hungary), in measurement of acute hyperoxia-induced increase in arterial stiffness in human subjects. SphygmoCor determines AIx based on the principle of applanation tonometry on radial artery using strain gauge transducer placed on the tip of a pencil-type tonometer. Arteriograph determines AIx by oscillometric method that measures periodic pressure changes in the inflated cuff induced by fluctuations in pulsatile pressure in the brachial artery beneath. Ten healthy male volunteers, aged 20-35 years (mean body mass index of 24.2± 1.8 kg/m2), normolipidemic, nonsmokers, taking no medications and had no history of alcohol abuse, were recruited for the study. Subjects were asked to abstain from exercise, fruits, vegetables, dietary supplements, tea, alcoholic beverages, and caffeine- or theobromine-containing foods for 24 h before the experiment. All experiments were carried out in a quiet, temperature-controlled room maintained around 24°C and were started at 8 a.m. Subjects rested for 15 minutes in a supine position before measurement and remained in that position throughout the four-hour study protocol, abstaining from any food or additional beverages. They breathed 100% O2 for 30 minutes between 60th and 90th min of the protocol. Oxygen was administered at the rate of 15 L/min via non-rebreathing mask. Pulse wave augmentation index (AIx), heart rate (HR), systolic, diastolic and mean arterial pressure (MAP) were determined at the beginning and after 60, 90, 120, 150 and 240 min of the experimental protocol. Significant increase of AIx occurred during 30 min of hyperoxia, from control values of -62 to -41% and from -58 to -42%, as determined by Arteriograph and SphygmoCor, respectively. After exposure to oxygen, AIx values partially recovered and, at the end of the experimental protocol, were -52 and -55%, as determined by Arteriograph and SphygmoCor, respectively. HR and MAP values did not change during the experiment. AIx values obtained by Arteriograph and SphygmoCor strongly correlated throughout the study (r = 0.89, p < 0.0001, n = 60). Our study indicates that the oscillometric determination of acute changes in AIx, by Arteriograph, is equally effective as the tonometric method, by SphygmoCor. Moreover, we found Arteriograph to be more investigator-independent and handy instrument. Arteriograph could be useful in assessment of acute changes in vascular function, such as in interventional pharmacological studies.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti, Kliničke medicinske znanosti

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