Blood pressure response to LBNP load in various types of examinations

Abstract

The original method of our LBNP (Lower Body Negative Pressure) examination was developed for the pre-selection of pilots with low +Gz tolerance. Flights with alternating ±Gz acceleration in agile aircraft invoke a cardiovascular response of the organism so-called Push-Pull (PP) effect. This phenomenon is characterized by rapid and progressive decrease of blood pressure (BP) accompanied by a slower return to normality during +Gz load following immediately after -Gz load. It is just the slower return of BP to the standard value after its previous substantial decrease which is a very dangerous in-flight factor. Our LBNP device was reconstructed in order not only to allow estimation of the +Gz tolerance level but also to find pilots with low tolerance to the PP effect. We developed the new LBNP examination method with the simulation of the PP effect that is an important training stage preceding pilots' centrifuge training. BP which stands for a significant parameter reflecting the cardiovascular regulation level responds very sensitively to the LBNP exposure. BP changes during LBNP exposition correspond very well to in-flight PP effect. © 2009 Springer Berlin Heidelberg.