Related Experiment Videos
Effects of transient intrathoracic pressure changes (hiccups) on systemic arterial pressure
1Department of Pediatrics, East Carolina University School of Medicine, Greenville, North Carolina 27858, USA.
Insights
Hiccups transiently decrease intrathoracic pressure, significantly lowering systemic arterial pressure in preterm infants. This effect is primarily due to increased thoracic aorta volume, impacting blood pressure regulation.
Area of Science:
- Physiology
- Neonatal Medicine
- Cardiovascular Research
Background:
- Transient changes in intrathoracic pressure can affect systemic arterial pressure.
- Hiccups provide a physiological model to study these transient pressure changes.
Purpose of the Study:
- To investigate the impact of transient intrathoracic pressure variations on systemic arterial pressure.
- To utilize hiccups as a tool to assess these physiological effects in intubated preterm infants.
Main Methods:
- Measured systolic and diastolic pressures before, during, and after hiccups in 10 intubated preterm infants.
- Analyzed pressure changes associated with early-systolic, late-systolic, early-diastolic, and late-diastolic hiccups.
Main Results:
- Early-systolic hiccups significantly decreased systolic blood pressure compared to controls.
- Diastolic pressure decreased significantly when hiccups occurred during diastole.
- Late-diastolic hiccups led to a decrease in subsequent systolic pressures.
Conclusions:
- Transient decreases in intrathoracic pressure reduce systemic arterial pressure, mainly via increased thoracic aorta volume.
- Reduced stroke volume contributes to the observed decrease in systolic pressure.
Abstract:
The purpose of the study was to determine the effect of transient changes in intrathoracic pressure on systemic arterial pressure by utilizing hiccups as a tool. Values of systolic and diastolic pressures before, during, and after hiccups were determined in 10 intubated preterm infants. Early-systolic hiccups decreased systolic blood pressure significantly (P < 0.05) compared with control (39.38 +/- 2.72 vs. 46.46 +/- 3.41 mmHg) and posthiccups values, whereas no significant change in systolic blood pressure occurred during late-systolic hiccups. Diastolic pressure immediately after the hiccups remained unchanged during both early- and late-systolic hiccups. In contrast, diastolic pressure decreased significantly (P < 0.05) when hiccups occurred during diastole (both early and late). Systolic pressures of the succeeding cardiac cycle remained unchanged after early-diastolic hiccups, whereas they decreased after late-diastolic hiccups. These results indicate that transient decreases in intrathoracic pressure reduce systemic arterial pressure primarily through an increase in the volume of the thoracic aorta. A reduction in stroke volume appears to contribute to the reduction in systolic pressure.