Ambient temperature and the occurrence of intradialytic hypotension in patients receiving hemodialysis

Kuan-Hung Liu; Wei-Hsiang Chang; Edward Chia-Cheng Lai; Pei-Chen Tsai; Bin Hsu; Yu-Hsuan Yang; Wei-Ren Lin; Tzu-Shan Huang; Fang-Yi Su; Jung-Hsien Chiang; Chung-Yi Li; Yau-Sheng Tsai; Junne-Ming Sung

doi:10.1093/ckj/sfad304

Ambient temperature and the occurrence of intradialytic hypotension in patients receiving hemodialysis

Clin Kidney J. 2023 Dec 21;17(1):sfad304. doi: 10.1093/ckj/sfad304. eCollection 2024 Jan.

Authors

Kuan-Hung Liu^{1

2}, Wei-Hsiang Chang^{3

4}, Edward Chia-Cheng Lai⁵, Pei-Chen Tsai⁶, Bin Hsu², Yu-Hsuan Yang¹, Wei-Ren Lin^{1

2}, Tzu-Shan Huang², Fang-Yi Su⁶, Jung-Hsien Chiang⁶, Chung-Yi Li^{7

8

9}, Yau-Sheng Tsai¹, Junne-Ming Sung^{1

2}

Affiliations

¹ Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
² Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
³ Department of Food Safety/ Hygiene and Risk Management, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
⁴ Research Center of Environmental Trace Toxic Substances, National Cheng Kung University, Tainan, Taiwan.
⁵ School of Pharmacy, Institute of Clinical Pharmacy and Pharmaceutical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
⁶ Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan, Taiwan.
⁷ Department of Public Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
⁸ Department of Public Health, College of Public Health, China Medical University, Taichung, Taiwan.
⁹ Department of Healthcare Administration, College of Medical and Health Science, Asia University, Taichung, Taiwan.

Abstract

Background: Intradialytic hypotension (IDH) is a common hemodialysis complication causing adverse outcomes. Despite the well-documented associations of ambient temperatures with fluid removal and pre-dialysis blood pressure (BP), the relationship between ambient temperature and IDH has not been adequately studied.

Methods: We conducted a cohort study at a tertiary hospital in southern Taiwan between 1 January 2016 and 31 October 2021. The 24-h pre-hemodialysis mean ambient temperature was determined using hourly readings from the weather station closest to each patient's residence. IDH was defined using Fall40 [systolic BP (SBP) drop of ≥40 mmHg] or Nadir90/100 (SBP <100 if pre-dialysis SBP was ≥160, or SBP <90 mmHg). Multivariate logistic regression with generalizing estimating equations and mediation analysis were utilized.

Results: The study examined 110 400 hemodialysis sessions from 182 patients, finding an IDH prevalence of 11.8% and 10.4% as per the Fall40 and Nadir90/100 criteria, respectively. It revealed a reverse J-shaped relationship between ambient temperature and IDH, with a turning point around 27°C. For temperatures under 27°C, a 4°C drop significantly increased the odds ratio of IDH to 1.292 [95% confidence interval (CI) 1.228 to 1.358] and 1.207 (95% CI 1.149 to 1.268) under the Fall40 and Nadir90/100 definitions, respectively. Lower ambient temperatures correlated with higher ultrafiltration, accounting for about 23% of the increased IDH risk. Stratified seasonal analysis indicated that this relationship was consistent in spring, autumn and winter.

Conclusion: Lower ambient temperature is significantly associated with an increased risk of IDH below the threshold of 27°C, irrespective of the IDH definition. This study provides further insight into environmental risk factors for IDH in patients undergoing hemodialysis.

Keywords: ambient temperature; hemodialysis; intradialytic hypotension; seasonal variation; threshold.