Abstract

Background: Patients in Intensive Care Units (ICUs) face significant distress, elevating their risk for post-traumatic stress disorder (PTSD) (Abdelbaky & Eldelpshany, 2024; Righy et al., 2019). PTSD arises from complex psychoneuroimmunological interactions (Katrinli, Oliveira, Felger, Michopoulos, & Smith, 2022). Autonomic dysregulation, indexed by reduced heart rate variability (HRV), is a known correlate of PTSD (Schneider & Schwerdtfeger, 2020). Evidence also links PTSD to chronic inflammation, with markers like C-reactive protein (CRP) implicated (Kim et al., 2025; Peruzzolo et al., 2022). However, integrated psychoneuroimmunological research in ICU-related PTSD is limited.

Purpose: To examine the relationships between psychological (anxiety, pain, sleep quality), neurological (HRV), and immune (IL-6 and CRP) responses and the development of PTSD in ICU patients.

Methods: This prospective study recruited postoperative abdominal surgery patients from an ICU in northern Taiwan. Data was collected at four time points: endotracheal tube removal (T1), ICU discharge (T2), and three months post-discharge (T3). Instruments included the Numerical Rating Scales for Anxiety and Pain (NRS-A/P), Richards-Campbell Sleep Questionnaire, PTSD Checklist (PCL-5), HRV, and serum IL-6/CRP. Data were analyzed using logistic and multinomial regression.

Results: Of 73 patients, 13 (17.8%) developed PTSD. ICU delirium (p = 0.007) and infrequent family visitation (p = 0.003) were significant clinical predictors. Anxiety at ICU discharge (T2) was highly associated with PTSD risk (OR=1.98, p < 0.001). Lower HRV, indicating autonomic dysregulation, also increased risk; higher SDNN at T2 (OR = 0.07, p = 0.003) and T3 (OR = 0.07, p = 0.002) showed a strong protective effect. Elevated CRP at T1 (OR = 3.28, p = 0.046) and T2 (OR = 4.05, p = 0.030) was linked to increased PTSD risk. The most robust model at T2, combining anxiety and SDNN, explained 60.2% of PTSD variance (Nagelkerke R2 = 0.602).

Conclusion: Anxiety, reduced HRV (SDNN), and elevated CRP are key psychoneuroimmunological predictors of PTSD in ICU survivors. ICU discharge is a critical screening window where these factors converge. Early screening of these markers may enable targeted interventions to mitigate PTSD risk and promote recovery.

Notes

References:

Abdelbaky, A. M., & Eldelpshany, M. S. (2024). Intensive Care Unit (ICU)-Related Post-traumatic Stress Disorder: A Literature Review. Cureus, 16(3), e57049. doi:10.7759/cureus.57049

Katrinli, S., Oliveira, N. C. S., Felger, J. C., Michopoulos, V., & Smith, A. K. (2022). The role of the immune system in posttraumatic stress disorder. Translational Psychiatry, 12(1), 313. doi:10.1038/s41398-022-02094-7

Kim, J. M., Kim, J. W., Ju, J. K., Jhon, M., Kang, H. J., Lee, J. Y., . . . Shin, I. S. (2025). Associations of heart rate variability at early post-injury with later post-traumatic stress disorder over two years. Journal of Psychiatry Research, 188, 276-283. doi:10.1016/j.jpsychires.2025.05.032

Peruzzolo, T. L., Pinto, J. V., Roza, T. H., Shintani, A. O., Anzolin, A. P., Gnielka, V., . . . Passos, I. C. (2022). Inflammatory and oxidative stress markers in post-traumatic stress disorder: a systematic review and meta-analysis. Molecular Psychiatry, 27(8), 3150-3163. doi:10.1038/s41380-022-01564-0

Righy, C., Rosa, R. G., da Silva, R. T. A., Kochhann, R., Migliavaca, C. B., Robinson, C. C., . . . Falavigna, M. (2019). Prevalence of post-traumatic stress disorder symptoms in adult critical care survivors: a systematic review and meta-analysis. Critical Care, 23(1), 213. doi:10.1186/s13054-019-2489-3

Schneider, M., & Schwerdtfeger, A. (2020). Autonomic dysfunction in posttraumatic stress disorder indexed by heart rate variability: a meta-analysis. Psychological Medicine, 50(12), 1937-1948. doi:10.1017/s003329172000207x

Description

This study identifies a psychoneuroimmunological model for predicting PTSD in ICU survivors. The findings show that anxiety (psychological), reduced heart rate variability (autonomic), and elevated C-reactive protein (immune) collectively predict PTSD risk. A model combining anxiety and HRV at ICU discharge explained 60.2% of variance, highlighting a critical screening window for targeted interventions to mitigate PTSD risk.

Author Details

Yu-Ju Chen, PhD; Pei-Yu Hou, MSN; Ching-I Li, BSN

Sigma Membership

Lambda Beta at-Large

Type

Poster

Format Type

Text-based Document

Study Design/Type

Longitudinal Study

Research Approach

Quantitative Research

Keywords:

Psychoneuroimmunology, Critically Ill Patients--Psychosocial Factors, Critically Ill Patients, Intensive Care Units, Post-Traumatic Stress Disorders, Post-Traumatic Stress Disorders--Risk Factors

Conference Name

37th International Nursing Research Congress

Conference Host

Sigma Theta Tau International

Conference Location

Toronto, Ontario, Canada

Conference Year

2026

Rights Holder

All rights reserved by the author(s) and/or publisher(s) listed in this item record unless relinquished in whole or part by a rights notation or a Creative Commons License present in this item record. All permission requests should be directed accordingly and not to the Sigma Repository. All submitting authors or publishers have affirmed that when using material in their work where they do not own copyright, they have obtained permission of the copyright holder prior to submission and the rights holder has been acknowledged as necessary.

Review Type

Abstract Review Only: Reviewed by Event Host

Acquisition

Proxy-submission

Date of Issue

2026-08-05

Click on the above link to access the poster.

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Psychoneuroimmunological Predictors of PTSD in ICU Patients

Toronto, Ontario, Canada

Background: Patients in Intensive Care Units (ICUs) face significant distress, elevating their risk for post-traumatic stress disorder (PTSD) (Abdelbaky & Eldelpshany, 2024; Righy et al., 2019). PTSD arises from complex psychoneuroimmunological interactions (Katrinli, Oliveira, Felger, Michopoulos, & Smith, 2022). Autonomic dysregulation, indexed by reduced heart rate variability (HRV), is a known correlate of PTSD (Schneider & Schwerdtfeger, 2020). Evidence also links PTSD to chronic inflammation, with markers like C-reactive protein (CRP) implicated (Kim et al., 2025; Peruzzolo et al., 2022). However, integrated psychoneuroimmunological research in ICU-related PTSD is limited.

Purpose: To examine the relationships between psychological (anxiety, pain, sleep quality), neurological (HRV), and immune (IL-6 and CRP) responses and the development of PTSD in ICU patients.

Methods: This prospective study recruited postoperative abdominal surgery patients from an ICU in northern Taiwan. Data was collected at four time points: endotracheal tube removal (T1), ICU discharge (T2), and three months post-discharge (T3). Instruments included the Numerical Rating Scales for Anxiety and Pain (NRS-A/P), Richards-Campbell Sleep Questionnaire, PTSD Checklist (PCL-5), HRV, and serum IL-6/CRP. Data were analyzed using logistic and multinomial regression.

Results: Of 73 patients, 13 (17.8%) developed PTSD. ICU delirium (p = 0.007) and infrequent family visitation (p = 0.003) were significant clinical predictors. Anxiety at ICU discharge (T2) was highly associated with PTSD risk (OR=1.98, p < 0.001). Lower HRV, indicating autonomic dysregulation, also increased risk; higher SDNN at T2 (OR = 0.07, p = 0.003) and T3 (OR = 0.07, p = 0.002) showed a strong protective effect. Elevated CRP at T1 (OR = 3.28, p = 0.046) and T2 (OR = 4.05, p = 0.030) was linked to increased PTSD risk. The most robust model at T2, combining anxiety and SDNN, explained 60.2% of PTSD variance (Nagelkerke R2 = 0.602).

Conclusion: Anxiety, reduced HRV (SDNN), and elevated CRP are key psychoneuroimmunological predictors of PTSD in ICU survivors. ICU discharge is a critical screening window where these factors converge. Early screening of these markers may enable targeted interventions to mitigate PTSD risk and promote recovery.