# S-ketamine plus dexmedetomidine vs. S-ketamine plus propofol for sedation–analgesia during positioning for spinal anesthesia in older adults undergoing lower extremity fracture surgery

## TL;DR

This study compares two sedation methods for older adults during spinal anesthesia for leg fractures, finding that one provides better pain control and comfort.

## Contribution

The study introduces a novel comparison of S-ketamine plus dexmedetomidine versus S-ketamine plus propofol for sedation during spinal positioning in elderly patients.

## Key findings

- Dexmedetomidine-based sedation reduced pain during critical positioning stages and improved posture quality.
- Physiological differences were modest, with slightly higher SpO2 and lower heart rate and blood pressure in the dexmedetomidine group.
- Adverse events were rare in both groups, with no delirium cases in the dexmedetomidine group.

## Abstract

Positioning for neuraxial anesthesia in geriatric lower extremity fracture surgery is painful and can destabilize hemodynamics. Sedation–analgesia must balance effective analgesia with respiratory safety and physiologic stability.

This single-center retrospective cohort study included patients aged ≥65 years undergoing lower extremity fracture surgery under spinal anesthesia who received S-ketamine plus dexmedetomidine (Group A, n = 48) or S-ketamine plus propofol (Group B, n = 46). Primary outcomes included a numerical rating scale (NRS) positioning pain score of 0–10 and an ordinal posture quality score measured at five stages (T1–T5). Repeated measures were analyzed using mixed-effects models (group, stage, group×stage; random: patient) with covariate adjustment. Stage-wise contrasts were Holm-corrected.

A total of 100 records were screened, and 94 patients were analyzed. Group×stage interactions were significant for pain and posture quality. Group A had lower pain during the most noxious stages (T3–T5; adjusted differences −0.42 to −0.50) and higher odds of better posture quality (OR 2.30–2.70). Physiological differences were modest and stage-specific, with slightly higher SpO2 and lower heart rate (HR)/mean arterial pressure (MAP) at T2–T3. Postoperative NRS differed only at 12 h. Adverse events were infrequent; delirium was identified from routine documentation without a standardized instrument (0/48 vs. 2/46).

In this retrospective cohort, dexmedetomidine-based sedation with S-ketamine was associated with improved comfort and cooperation during spinal positioning compared with propofol-based sedation, while adverse events were infrequent in both groups.