engleski

Muscle oxygen desaturation in apnea divers determined with near infrared spectroscopy (NIRS)

During spire gun fishing practice skeletal muscles of apnea divers suffer from severe oxygen depletion. Whether these muscles adapt to these intense metabolic demands is less known. The purpose of this study was to investigate level of oxygen desaturation in calf skeletal muscle during series of breath-hold apneas. Four apnea divers and four control subjects performed five maximal apneas with face immersion into cold water (10-12 °C) with two-minute interval between each breath-hold. Arterial blood pressure, heart rate, and movement of respiratory musculature were continuously monitored and stored on personal computer. Muscle oxygen saturation of the calf skeletal muscle was incessantly measured with near infrared spectroscopy method using a 25 mm probe, and data stored on personal computer for later analysis. In both groups duration of apnea increased from first breath-hold and reached plateau by third apnea. Total duration of five apneas was significantly longer for apnea divers (788.8± ; ; 20.7 s) in comparison to control subjects (412.3± ; ; 56.6 s). Similarly, changes in mean blood pressure and heart rate were more pronounced in apnea divers than in control population (160 mmHg and 43 beats per minute and 130 mmHg and 55 beats per minute, for apnea divers and control subjects, respectively). In accordance with duration of breath-holds, calf skeletal muscles of apnea divers desaturated greatly (from 85.0± ; ; 4.7% to 56.5± ; ; 11.3%) compared to controls (from 83.8± ; ; 4.7% to 73.8± ; ; 5.3%). However, muscle oxygen saturation data for apnea divers at the maximal times achieved by control subjects showed small decrease from baseline (to 78.3± ; ; 5.2%). We conclude that apnea divers developed certain metabolic adaptations, which allow them to prolong time of breath-hold without exposing their muscle to reduced oxygen content.

nije evidentirano

nije evidentirano