Red Cell and Core Temperature in Spelunking

Abstract

Alpine spelunking is practiced in darkness, isolation, cold and high humidity. In this paper we study the acute haematological effects of prolonged strenuous activity in five spelunkers who spent about 20 hours in a 700-meter deep cave without resting much or sleeping. On four occasions, we measured their red cell counts, haemoglobin, mean corpuscular volume and percentage changes of plasma volume. We also measured their rectal temperature to estimate, in the limits of this parameter, thermoregulatory response. After the spelunkers descended 5 hours to the bottom of the cave, we detected, in all of them, a significant increase in red cell counts and haemoglobin and a drop in mean corpuscular volume and plasma volume. The day after recovery, we found a significant drop in all red cell parameters and a rise in plasma volumes. Rectal temperatures peaked at the exit. These findings suggest that alpine spelunking induces an initial haemoconcentration (bottom of the cave) followed by a haemodilution (the day after recovery). Sport anaemia was not detected. The rise of rectal temperature suggests that spelunking is a very strenuous sport with possible transpiration problems.

Human Physiology During Exposure to the Cave Environment: A Systematic Review With Implications for Aerospace Medicine

“…Cave/lab simulation exercises were performed in all studies; exercise can be classified as cave progression (characterized by atypical, strenuous movement, often combining ascent, descent, and scrambling activity) in all studies apart from one, where an exercise stress test in the simulated cave-environment condition was completed (Maura et al, 2008). Anthropometric characteristics were measured in the majority of the studies (Vacca et al, 1994; Bratima et al, 1999; Stenner, 2002; Bregani et al, 2005; Stenner et al, 2006, 2007a,b; Maura et al, 2008; Antoni et al, 2017; Pinna et al, 2017). Overall, study subjects were healthy with heterogeneous anthropometric characteristics.…”

“…A previous study demonstrated an initial increase in red blood cell (RBC) count and hemoglobin (Hb) concentration after only ~5 h of cave exploration, although this increase was in parallel with a concomitant reduction in plasma volume (PV) (Stenner et al, 2007b). Previous work from the same research group demonstrated that the number of leucocytes, neutrophils, monocytes, and platelets were significantly increased after cave progression, whereas lymphocytes showed a concomitant significant reduction (Stenner et al, 2006).…”

“…Equally, previous research related to endocrine and immune-hematological changes not only showed the potential for an anticipatory stress reaction to the cave environment, based on increased cortisol levels (Stenner et al, 2007a), but also suggested that there may be a compensatory response to both exercise and environment [evidenced by decreased cortisol levels and restoration of GH levels 24 h post cave exit (Stenner et al, 2006, 2007a,b)]. Due to the pulsatile nature of GH levels in the blood, conventional measurements of serum GH are highly variable dependent on a number of environmental stressors.…”

“…Accurate data collection in these challenging environments still remains predominantly a technological challenge, but it is an area where large gains could be made once movement patterns and profiling of such atypical, specialist movement are better characterized. However, even with fundamental assessment, many studies have postulated an inadequate restoration of lost calories and fluid in relation to the level and duration of movement recorded in the cave environment (Vacca et al, 1994; Bratima et al, 1999; Stenner, 2002; Stenner et al, 2007b; Antoni et al, 2017). Moreover, water losses during cave activity may also lead to acute hematological modification (i.e., increase in red blood cells and hemoglobin) as hypothesized by Stenner et al (2007b).…”

“…Finally, cave progression can include prolonged, multimodal, challenging traverse activity with intensive moments that can induce skeletal muscle damage and intravascular hemolysis also accompanied by the activation of inflammatory cells, as shown by the increased levels of CK and LDH, decreased level of haptoglobin and the significant increase in leucocytes due to neutrophila and monocytosis (Bregani et al, 2005; Stenner et al, 2006). These responses seem to be related both to the intensity of the exercise, pre-determined fitness/training level, overall fluid losses and the level of physiological strain induced by the specific atmospheric environmental conditions of the cave environment (Stenner et al, 2007b), and could be reduced by a specific diet. Specifically, supplementation of creatine seems to mitigate muscular damage, which typically occurs during cave progression (Bregani et al, 2005).…”