Summary: | Objective
Lactate, as an indicator of hypoxia, may be useful in sleep-related breathing disorders to identify higher risk groups and monitor the effectiveness of positive airway pressure (PAP) treatment. We aimed to investigate the change in arterial lactate level in blood after PAP treatment in patients with obstructive sleep apnea (OSA) and sleep-related hypoventilation and hypoxemic syndromes and its applicability for monitoring this change regarding the effectiveness of the treatment.
Materials and Methods
PAP titration was applied to 64 OSA patients diagnosed with polysomnography. Measurements included pulmonary function testing, overnight PAP titration, arterial blood gases, and analysis of arterial lactate before and after titration. Overnight lactate level change was calculated.
Results
Of the 64 patients in the study, 49 were in the OSA group and 15 were in the Obesity Hypoventilation syndrome plus OSA group. No statistically significant difference was detected among the patients in terms of lactate levels before and after PAP treatment [1.97 (±0.7) - 1.98 (±0.6)] (p>0.05). In the OSA patient group, we detected an inverse relationship between Lactate and pre-treatment non-rapid eye movement 1-2% (r=-0.328, p=0.021), T 90% (r=-0.356, p=0.012), and total apnea hypopnea index (AHI) (r=-0.424, p=0.002). Lactate is found to be positively correlated with pre-treatment measured oxygen saturation (r=0.396, p=0.005), and with minimum oxygen saturation (r=0.361, p=0.011).
Conclusion
Our study showed that there is a relationship between AHI, average and minimum oxygen saturation and T 90% and lactate difference, which are severity indicators for OSA. These results suggest that PAP treatment may prevent possible lactate increase.
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