Globally, rapid population aging—particularly in Korea—has extended life expectancy but not proportionally extended healthy life expectancy, resulting in longer periods of illness or disability and a higher demand for complex medical and social care. Therefore, prolonging healthy life and improving health-related quality of life have become primary objectives in geriatric medicine and rehabilitation. Geriatric rehabilitation is a critical intervention aimed at optimizing the functioning of older adults and pre-morbidly frail individuals who have lost independence due to acute illness or injury. For many older patients, the goal shifts from complete recovery to achieving a new equilibrium, maximizing autonomy despite greater dependency. Geriatric rehabilitation also targets key geriatric syndromes such as frailty, recognizing it as a dynamic and potentially reversible state that provides a crucial “time window” for intervention. This review summarizes the core principles and structural elements essential for geriatric rehabilitation, emphasizing the implementation challenges within the Korean healthcare system. Unlike the European consensus, which supports structured inpatient and outpatient services with seamless transitions of care guided by Comprehensive Geriatric Assessment, the Korean healthcare system remains fragmented and heavily centered on acute hospitals. This highlights the urgent need for a systematic model to integrate care facilities and strengthen interprofessional collaboration to support community-based “aging in place.” Effective geriatric rehabilitation requires multidisciplinary teams and multifaceted approaches to optimize quality of life, social participation, and independent living. Despite its importance, substantial awareness gaps and policy barriers persist, underscoring an urgent call to action.

Objectives

Spectral analysis of heart rate variability(HRV) resulted in a characteristic power spectrum with two main regions, a high frequency at 0.15-0.5Hz(HFP) corresponding to the parasympathetic system and a low frequency at 0.017-0.l5Hz(LFP) corresponding to both parasympathetic and sympathetic influences. The ratio of low : high frequency(LFP/HFP) has been postulated as an index of sympathetic activation. We propose that the LFP/HFP ratio will provide important information concerning autonomic nervous system activity during spinal anesthesia especially geriatric patients.

Methods

LFP, HFP and LFP/HFP were checked in 30 patients at the baseline and 5, 10, 15, 20, 25 and 30 minutes after subarachnoidal block. We divided patients into two groups: group 1 is 15 patients under 60 years old and group 2 is 15 patients over 65 years old, and we compared those parameters in both groups.

Results

Spinal anesthesia did produce a significant decrease in LFP and HFP in both groups. But sympathetic-parasympathetic balance(LFP/HFP) increased at 5 minutes after spinal block. In group 1, LFP/HFP decreased at 10 minutes after spinal block, thereafter increased gradually. In group 2, LFP/HFP decreased at 10, 15 and 20 minutes and increased at 25 and 30 minutes after spinal block.

Conclusion

These data suggest that autonomic tone decreased with spinal anesthesia and sympathetic-parasympathetic balance decreased for a long time in geriatric patients.