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The effect of hyperoxia on central blood pressure in healthy subjects

View Article: PubMed Central - PubMed

ABSTRACT

Introduction: Hyperoxia increases total peripheral resistance by acting locally but also inhibits the activity of carotid body chemoreceptors. We studied the effect of hyperoxia on central pressure in normotensive subjects.

Material and methods: Medical air followed by 100% oxygen was provided to 19 subjects (12/7 female/male, age 28.2 ±1.1 years) for 15 min through a non-rebreather mask. Central blood pressure was then measured using applanation tonometry.

Results: After the first 2 min of hyperoxia, heart rate decreased significantly (65 ±2.6 beats/min vs. 61 ±2.1 beats/min, p = 0.0002). Peripheral and central blood pressure remained unchanged, while hemoglobin oxygen saturation and subendocardial viability ratio index increased (97 ±0.4% vs. 99 ±0.2%, p = 0.03; 168 ±8.4% vs. 180 ±8.2%, p = 0.009). After 15 min of 100% oxygen ventilation, heart rate and peripheral and central blood pressures remained unchanged from the first 2 min. The augmentation index, augmentation pressure and ejection duration increased as compared to baseline values and those obtained at 2 min (–5.1 ±2.9% vs. –1.2 ±2.6%, p = 0.005 and –4.6 ±2.7% vs. –1.2 ±2.6%, p = 0.0015; –1.3 ±0.7 mm Hg vs. –0.2 ±1.2 mm Hg, p = 0.003 and –1.1 ±0.7 mm Hg vs. –0.2 ±1.2 mm Hg, p = 0.012; 323 ±3.6 ms vs. 330 ±3.5 ms, p = 0.0002 and 326 ±3.5 ms vs. 330 ±3.5 ms, p = 0.021, respectively).

Conclusions: The present study shows that hyperoxia does not affect central blood pressure in young healthy subjects and may improve myocardial blood supply estimated indirectly from applanation tonometry.

No MeSH data available.


Related in: MedlinePlus

Subendocardial viability ratio (SEVR), ejection duration (ED), augmentation pressure (AP) and augmentation index (AI) at baseline (P0) and after 2 (P1) and 15 min (P2) of 100% oxygen breathing. Data presented as means ± SEM
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Figure 0003: Subendocardial viability ratio (SEVR), ejection duration (ED), augmentation pressure (AP) and augmentation index (AI) at baseline (P0) and after 2 (P1) and 15 min (P2) of 100% oxygen breathing. Data presented as means ± SEM

Mentions: The baseline group characteristics are presented in Table I. For the primary variable, breathing 100% oxygen did not result in a significant change in central systolic and diastolic blood pressure between P0 and P1 (Table I). No changes were observed in the peripheral systolic and diastolic blood pressure values. Heart rate decreased significantly between P0 and P1 (65 ±2.6 beats/min vs. 61 ±2.1, beats/min, p = 0.0002) (Table I). SaO2 and SEVR increased likewise (97 ±0.4% vs. 99 ±0.2%, p = 0.03; 168 ±8.4% vs. 181 ±8.2%, p = 0.009, respectively) (Figure 3, Table I). After 15 min of 100% oxygen ventilation, peripheral and central systolic and diastolic blood pressures remained unchanged (Table I). A further decrease in heart rate was not observed (61 ±2.1 beats/min vs. 58 ±2.5 beats/min, NS). Augmentation pressure, augmentation index and ejection duration increased after 15 min of breathing 100% oxygen, as compared to baseline values and values obtained at P1 (Figure 3, Table I).


The effect of hyperoxia on central blood pressure in healthy subjects
Subendocardial viability ratio (SEVR), ejection duration (ED), augmentation pressure (AP) and augmentation index (AI) at baseline (P0) and after 2 (P1) and 15 min (P2) of 100% oxygen breathing. Data presented as means ± SEM
© Copyright Policy - open-access
Related In: Results  -  Collection

License
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getmorefigures.php?uid=PMC5016570&req=5

Figure 0003: Subendocardial viability ratio (SEVR), ejection duration (ED), augmentation pressure (AP) and augmentation index (AI) at baseline (P0) and after 2 (P1) and 15 min (P2) of 100% oxygen breathing. Data presented as means ± SEM
Mentions: The baseline group characteristics are presented in Table I. For the primary variable, breathing 100% oxygen did not result in a significant change in central systolic and diastolic blood pressure between P0 and P1 (Table I). No changes were observed in the peripheral systolic and diastolic blood pressure values. Heart rate decreased significantly between P0 and P1 (65 ±2.6 beats/min vs. 61 ±2.1, beats/min, p = 0.0002) (Table I). SaO2 and SEVR increased likewise (97 ±0.4% vs. 99 ±0.2%, p = 0.03; 168 ±8.4% vs. 181 ±8.2%, p = 0.009, respectively) (Figure 3, Table I). After 15 min of 100% oxygen ventilation, peripheral and central systolic and diastolic blood pressures remained unchanged (Table I). A further decrease in heart rate was not observed (61 ±2.1 beats/min vs. 58 ±2.5 beats/min, NS). Augmentation pressure, augmentation index and ejection duration increased after 15 min of breathing 100% oxygen, as compared to baseline values and values obtained at P1 (Figure 3, Table I).

View Article: PubMed Central - PubMed

ABSTRACT

Introduction: Hyperoxia increases total peripheral resistance by acting locally but also inhibits the activity of carotid body chemoreceptors. We studied the effect of hyperoxia on central pressure in normotensive subjects.

Material and methods: Medical air followed by 100% oxygen was provided to 19 subjects (12/7 female/male, age 28.2 ±1.1 years) for 15 min through a non-rebreather mask. Central blood pressure was then measured using applanation tonometry.

Results: After the first 2 min of hyperoxia, heart rate decreased significantly (65 ±2.6 beats/min vs. 61 ±2.1 beats/min, p = 0.0002). Peripheral and central blood pressure remained unchanged, while hemoglobin oxygen saturation and subendocardial viability ratio index increased (97 ±0.4% vs. 99 ±0.2%, p = 0.03; 168 ±8.4% vs. 180 ±8.2%, p = 0.009). After 15 min of 100% oxygen ventilation, heart rate and peripheral and central blood pressures remained unchanged from the first 2 min. The augmentation index, augmentation pressure and ejection duration increased as compared to baseline values and those obtained at 2 min (–5.1 ±2.9% vs. –1.2 ±2.6%, p = 0.005 and –4.6 ±2.7% vs. –1.2 ±2.6%, p = 0.0015; –1.3 ±0.7 mm Hg vs. –0.2 ±1.2 mm Hg, p = 0.003 and –1.1 ±0.7 mm Hg vs. –0.2 ±1.2 mm Hg, p = 0.012; 323 ±3.6 ms vs. 330 ±3.5 ms, p = 0.0002 and 326 ±3.5 ms vs. 330 ±3.5 ms, p = 0.021, respectively).

Conclusions: The present study shows that hyperoxia does not affect central blood pressure in young healthy subjects and may improve myocardial blood supply estimated indirectly from applanation tonometry.

No MeSH data available.


Related in: MedlinePlus