Association between admission serum potassium and quantitative external lumbar drainage responsiveness in patients with hydrocephalus: a retrospective study
- 1The Neurosurgery Department, The First Affiliated Hospital of Xinjiang Medical University , ,
Abstract
Objective: To evaluate the association between untreated admission serum potassium levels and quantitative responsiveness to external lumbar drainage (ELD) in patients with hydrocephalus.
Methods: This single-center retrospective study included 349 unique patients with hydrocephalus after reconciliation and deduplication of clinical records collected between 2020 and 2026. Serum potassium was defined as the first measurement obtained at hospital admission before treatment. ELD responsiveness was defined as an improvement of ≥10% in Timed Up and Go or 10-m walking time, ≥3 points in the Mini-Mental State Examination (MMSE), or ≥2 points in the Montreal Cognitive Assessment (MoCA). Multivariable logistic regression was used to assess the association between potassium and ELD responsiveness after adjustment for study period and eight clinical covariates. Sensitivity analyses examined medication exposure, potassium range, and alternative outcome definitions. Model performance was evaluated using bootstrap internal validation.
Results: Among 349 patients, 228 (65.3%) met the quantitative criteria for ELD responsiveness. Higher admission potassium was independently associated with greater odds of ELD responsiveness (adjusted OR per 0.1 mmol/L increase, 1.117; 95% CI, 1.038–1.201; p = 0.003). The association remained significant after exclusion of diuretic users (OR, 1.099; 95% CI, 1.017–1.188; p = 0.017). However, no significant association was observed among patients with potassium ≥3.5 mmol/L (OR, 1.043; 95% CI, 0.914–1.190; p = 0.536) or when a stricter definition of nonresponse was applied (OR, 1.076; 95% CI, 0.962–1.204; p = 0.200). The combined clinical-plus-potassium model achieved an apparent AUC of 0.757 and an optimism-corrected AUC of 0.725 (approximate 95% CI, 0.685–0.797). The corrected improvement in discrimination after adding potassium was small and uncertain.
Conclusion: Higher untreated admission serum potassium was independently associated with quantitative ELD responsiveness in this heterogeneous hydrocephalus cohort. However, the association was not demonstrated within the non-hypokalemic range, and the incremental predictive contribution of potassium beyond clinical variables remained uncertain. These findings support serum potassium as a potential clinical correlate of ELD responsiveness that warrants further validation in well-characterized prospective cohorts.
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BibTeX
@article{liu2026association,
title = {{Association between admission serum potassium and quantitative external lumbar drainage responsiveness in patients with hydrocephalus: a retrospective study}},
author = {Yu Liu and Xiaohu Ma and Yabin Li and Qiang Fu and Tengfei Liu and Yidan Luo and Hu Qin and Yongxin Wang},
journal = {Frontiers in neurology},
year = {2026},
month = sep,
doi = {10.3389/fneur.2026.1942880},
url = {https://europepmc.org/article/PMC/PMC13661376},
note = {CC BY},
}
RIS
TY - JOUR
TI - Association between admission serum potassium and quantitative external lumbar drainage responsiveness in patients with hydrocephalus: a retrospective study
AU - Yu Liu
AU - Xiaohu Ma
AU - Yabin Li
AU - Qiang Fu
AU - Tengfei Liu
AU - Yidan Luo
AU - Hu Qin
AU - Yongxin Wang
PY - 2026
DA - 2026/09/30
JO - Frontiers in neurology
DO - 10.3389/fneur.2026.1942880
UR - https://europepmc.org/article/PMC/PMC13661376
AB - Objective: To evaluate the association between untreated admission serum potassium levels and quantitative responsiveness to external lumbar drainage (ELD) in patients with hydrocephalus. Methods: This single-center retrospective study included 349 unique patients with hydrocephalus after reconciliation and deduplication of clinical records collected between 2020 and 2026. Serum potassium was defined as the first measurement obtained at hospital admission before treatment. ELD responsiveness was defined as an improvement of ≥10% in Timed Up and Go or 10-m walking time, ≥3 points in the Mini-Mental State Examination (MMSE), or ≥2 points in the Montreal Cognitive Assessment (MoCA). Multivariable logistic regression was used to assess the association between potassium and ELD responsiveness after adjustment for study period and eight clinical covariates. Sensitivity analyses examined medication exposure, potassium range, and alternative outcome definitions. Model performance was evaluated using bootstrap internal validation. Results: Among 349 patients, 228 (65.3%) met the quantitative criteria for ELD responsiveness. Higher admission potassium was independently associated with greater odds of ELD responsiveness (adjusted OR per 0.1 mmol/L increase, 1.117; 95% CI, 1.038–1.201; p = 0.003). The association remained significant after exclusion of diuretic users (OR, 1.099; 95% CI, 1.017–1.188; p = 0.017). However, no significant association was observed among patients with potassium ≥3.5 mmol/L (OR, 1.043; 95% CI, 0.914–1.190; p = 0.536) or when a stricter definition of nonresponse was applied (OR, 1.076; 95% CI, 0.962–1.204; p = 0.200). The combined clinical-plus-potassium model achieved an apparent AUC of 0.757 and an optimism-corrected AUC of 0.725 (approximate 95% CI, 0.685–0.797). The corrected improvement in discrimination after adding potassium was small and uncertain. Conclusion: Higher untreated admission serum potassium was independently associated with quantitative ELD responsiveness in this heterogeneous hydrocephalus cohort. However, the association was not demonstrated within the non-hypokalemic range, and the incremental predictive contribution of potassium beyond clinical variables remained uncertain. These findings support serum potassium as a potential clinical correlate of ELD responsiveness that warrants further validation in well-characterized prospective cohorts.
SN - 1664-2295
ER -