Psychophysiologic effects of applied tension on the emotional fainting response to blood and injury

Some authors included in their definition of fainter patients who came close to fainting during BII-relevant stimulus exposure or reported a history of feeling close to fainting when exposed to BII stimuli.

“Some authors have even included in their definition of “fainter” patients who came close to fainting during BII-relevant stimulus exposure (Öst, Lindahl, et al., 1984) or reported a history of feeling close to fainting when exposed to BII stimuli (Vögele et al., 2003).”

In some studies, fainters were characterized by their reported history of fainting in response to BII stimuli, but it is not always explicit whether researchers' and patients' definitions of fainting adhered to the criterion of rapid-onset, transient loss of consciousness.

“In some studies, fainters were characterized by their reported history of fainting in response to the sight of blood, injuries, or injections (e.g. Gerlach et al., 2006; Vögele et al., 2003), but it is not always explicit whether researchers’ and patients’ definitions of fainting actually adhered to the criterion of rapid-onset, transient loss of conscience.”

Only few studies have reported informative findings comparing subgroups of fainters and non-fainters, such as qualitatively different patterns of cardiovascular reactivity to BII-related material in blood-sensitive individuals with and without history of fainting.

“Not surprisingly, only few studies have reported informative findings comparing subgroups of fainters and non-fainters, such as qualitatively different patterns of cardiovascular reactivity to BII-related material in blood-sensitive individuals with and without history of fainting (Vögele et al., 2003).”

Three studies of surgery film exposure that used neutral film clips as a comparison were not able to demonstrate HR falls below neutral levels.

“Three studies of surgery film exposure that used neutral film clips as a comparison were not able to demonstrate HR falls below neutral levels (Sarlo et al., 2002; Steptoe and Wardle, 1988; Vögele et al., 2003).”

The latter two studies reported lower values of DBP during surgery compared to controls, but the observations were not substantiated by adequate significance tests.

“The latter two studies reported lower values of DBP during surgery compared to controls, but the observations were not substantiated by adequate significance tests.”

Studies have generally focused on respiration rate rather than full assessment of breathing pattern including volume or direct measures of expired CO2, so true hyperventilatory states may have been overlooked in most of these studies.

“However, studies have generally focused on respiration rate, such as through the measurement with a single strain gauge (e.g., Kozak & Miller, 1985; Steptoe & Wardle, 1988; Vögele et al., 2003) or visual observation of breathing (e.g., Cohn et al., 1976), rather than implementing a full assessment of the breathing pattern including volume or direct measures of expired CO2. Thus, true hyperventilAT”