The effects of acute blood loss on blood pressure recovery from the Valsalva maneuver.
Summary of "The effects of acute blood loss on blood pressure recovery from the Valsalva maneuver."
Human baroreflex regulation plays an important role in stabilising blood pressure. Though we have several indices to quantify cardiovagal responses, sympathetic baroreflex gain remains difficult to assess. We investigated how the recently validated pressure recovery time (PRT) and sympathetic baroreflex gain (SBRS) derived from the Valsalva maneuver was influenced by acute blood loss. 26 healthy blood donors were included in the study (age 35±15years; 20 men). SBRS was derived from the blood pressure drop (SAP delta) and pressure recovery time during the Valsalva maneuver. Besides we calculated cardiovagal baroreflex parameters, the Valsalva ratio (VR) and a simplified baroreflex gain (VBRS). We compared these parameters before and after the withdrawal of 350-400ml blood. The baseline systolic blood pressure was the same before and after blood donation (123±17 vs 126±23mm Hg, NS). The minimum systolic pressure (SAP min) during phase III was significantly lower, and the SAP delta significantly greater after blood withdrawal (SAP min 83±24mm Hg vs 69±27mm Hg, p<0.001; SAP delta 41±15mm Hg vs 57±16mm Hg, p<0.001). PRT increased significantly (from 2.0 to 3.6s, p<0.006). SBRS did not change between the study conditions (24±12mm Hg/s vs 22±10mm Hg/s, NS), nor did the VR and the
In conclusion, after the acute loss of approximately 350-400ml blood there was a greater blood pressure drop in phase II and III and a slower blood pressure recovery in phase IV of the Valsalva maneuver that resulted in an unchanged SBRS.
Gottsegen György National Institute of Cardiology, Hungary.
This article was published in the following journal.
Name: Autonomic neuroscience : basic & clinical
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/21147044
- DOI: http://dx.doi.org/10.1016/j.autneu.2010.11.008
Authors have collected and analyzed literature data on blood pressure variability. They present the methods of blood pressure variability measurement, clinical value and relationships with target orga...
Noise exposure is associated with elevated blood pressure, but the effects on susceptible workers have not been reported. This repeated-measure study investigated the effects of noise exposure on 24-h...
The prognostic role of high blood pressure and the aggressiveness of blood pressure lowering in dementia are not well characterized.
There is no scientific rationale to avoid blood pressure measurement on the same side as previous mastectomy, particularly if the patient has undergone lymph node removal or radiation therapy. Interar...
Device-guided breathing (DGB) is recommended by the American Heart Association for its blood pressure-lowering effects. Most previous studies that showed beneficial effects on blood pressure had low m...
The manipulation of blood pressure in acute cerebral ischemia has been a matter of debate until now. The investigators are clearly in need of more detailed data on how antihypertensive tre...
The study aimed to evaluate the chronic and acute effects of high-intensity resistance training on blood pressure and its hemodynamic and neural determinators in healthy normotensive older...
The purpose of this study is to determine whether blood pressure control by home blood pressure monitoring exerts beneficial cardioprotective effects rather than by clinic blood pressure m...
Exenatide is a new drug which lowers blood sugar (glucose) levels for people with type 2 diabetes. It has significant advantages over other treatments such as insulin as it causes weight l...
Insufficient blood pressure control is a frequent problem despite the existence of effective treatment. One of the causes is insufficient self-monitoring and a lack of adherence to therapy...
Medical and Biotech [MESH] Definitions
Excess blood loss from uterine bleeding associated with OBSTETRIC LABOR or CHILDBIRTH. It is defined as blood loss greater than 500 ml or of the amount that adversely affects the maternal physiology, such as BLOOD PRESSURE and HEMATOCRIT. Postpartum hemorrhage is divided into two categories, immediate (within first 24 hours after birth) or delayed (after 24 hours postpartum).
Method in which repeated blood pressure readings are made while the patient undergoes normal daily activities. It allows quantitative analysis of the high blood pressure load over time, can help distinguish between types of HYPERTENSION, and can assess the effectiveness of antihypertensive therapy.
A response by the BARORECEPTORS to increased BLOOD PRESSURE. Increased pressure stretches BLOOD VESSELS which activates the baroreceptors in the vessel walls. The net response of the CENTRAL NERVOUS SYSTEM is a reduction of central sympathetic outflow. This reduces blood pressure both by decreasing peripheral VASCULAR RESISTANCE and by lowering CARDIAC OUTPUT. Because the baroreceptors are tonically active, the baroreflex can compensate rapidly for both increases and decreases in blood pressure.
The sudden loss of blood supply to the PITUITARY GLAND, leading to tissue NECROSIS and loss of function (PANHYPOPITUITARISM). The most common cause is hemorrhage or INFARCTION of a PITUITARY ADENOMA. It can also result from acute hemorrhage into SELLA TURCICA due to HEAD TRAUMA; INTRACRANIAL HYPERTENSION; or other acute effects of central nervous system hemorrhage. Clinical signs include severe HEADACHE; HYPOTENSION; bilateral visual disturbances; UNCONSCIOUSNESS; and COMA.
PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.