Spleen volume and blood flow response to repeated breath-hold apneas

Abstract

The purpose of this study was 1) to answer whether the reduction in spleen size in breath-hold apnea is an active contraction or a passive collapse secondary to reduced splenic arterial blood flow and 2) to monitor the spleen response to repeated breath-hold apneas. Ten trained apnea divers and 10 intact and 7 splenectomized untrained persons repeated five maximal apneas (A1-A5) with face immersion in cold water, with 2 min interposed between successive attempts. Ultrasonic monitoring of the spleen and noninvasive cardiopulmonary measurements were performed before, between apneas, and at times 0, 10, 20, 40, and 60 min after the last apnea. Blood flows in splenic artery and splenic vein were not significantly affected by breath-hold apnea. The duration of apneas peaked after A3 (143, 127, and 74 s in apnea divers, intact, and splenectomized persons, respectively). A rapid decrease in spleen volume ( approximately 20% in both apnea divers and intact persons) was mainly completed throughout the first apnea. The spleen did not recover in size between apneas and only partly recovered 60 min after A5. The well-known physiological responses to apnea diving, i.e., bradycardia and increased blood pressure, were observed in A1 and remained unchanged throughout the following apneas. These results show rapid, probably active contraction of the spleen in response to breath-hold apnea in humans. Rapid spleen contraction and its slow recovery may contribute to prolongation of successive, briefly repeated apnea attempts.

Exercise induced hemoconcentration following spleen contraction in subjects with COPD

“…Interestingly, apnea in splenectomized subjects was found not to induce a Hb increase [5], and neonates with asplenia showed impaired transient elevation of blood Hb in response to acute hypoxia [8]. Bakovic and associates concluded that the contraction is an active process, as no differences in blood flow in the splenic artery or vein occurred [9], and total plasma protein levels remained unchanged across apnea series ruling out extravasation of plasma [5].…”

Does breath-holding increase the risk of a thrombotic event?

“…We and others have previously shown that voluntary breath-hold triggers splenic contraction [6,7]. Our aim was to test the hypothesis that voluntary breathholds are also associated with an increase in MPV.…”

Comparison of Selected Morphological, Rheological and Biochemical Parameters of Winter Swimmers' Blood at the End of One Winter Swimming Season and at the Beginning of Another

“…In contrast, they did not observe significant variations in the values of erythrocyte indices, such as MCH, MCV and MCHC (LOMBARDI et al 2011). Also BAKOVIC et al (2003) demonstrated that immersion in water (12°C) results in an increase in erythrocyte, leukocyte and thrombocyte counts, and interpreted this phenomenon as an adaptation to exercise performed in cold water. LUKASKI et al (1990) did not document significant changes in the concentration of hemoglobin and hematocrit level of winter swimmers, but observed an increase in the level of iron metabolism marker, ferritin.…”