Research

Risk factors for post-traumatic stress disorder symptoms following critical illness requiring mechanical ventilation: a prospective cohort study

Timothy D Girard^1,2 , Ayumi K Shintani³ , James C Jackson^1,2,4 , Sharon M Gordon^2,4,5 , Brenda T Pun¹ , Melinda S Henderson⁶ , Robert S Dittus^2,5,6 , Gordon R Bernard¹ and E Wesley Ely^1,2,5

¹  Department of Medicine; Division of Allergy, Pulmonary, and Critical Care Medicine; Vanderbilt University School of Medicine; T-1218 MCN, Nashville, TN 37232-2650, USA

²  Center for Health Services Research; Vanderbilt University School of Medicine; 6th Floor MCE, Suite 6100, Nashville, TN 37232-8300, USA

³  Department of Biostatistics; Vanderbilt University School of Medicine; S-2323 MCN, Nashville, TN 37232-2158, USA

⁴  Department of Psychiatry; Vanderbilt University School of Medicine; 1601 23rd Avenue South, Suite 3060, Nashville, TN, 37212, USA

⁵  Veterans Affairs Tennessee Valley Geriatric Research, Education, and Clinical Center; 1310 24th Avenue South, Nashville, TN 37212-2637, USA

⁶  Division of General Internal Medicine; Vanderbilt University School of Medicine; 6th Floor MCE, Suite 6000; Nashville, TN, 37232-8300, USA

author email corresponding author email

Critical Care 2007, 11:R28doi:10.1186/cc5708

Published:	22 February 2007

See related commentary by Weinart and Meller, http://ccforum/content/11/1/118, related reasearch by Jackson et al., http://ccforum.com/content/11/1/R27, and related research by Boer et al., http://ccforum.com/content/11/1/R30.

Abstract

Introduction

Post-traumatic stress disorder (PTSD) has been identified in a significant portion of intensive care unit (ICU) survivors. We sought to identify factors associated with PTSD symptoms in patients following critical illness requiring mechanical ventilation.

Methods

Forty-three patients who were mechanically ventilated in the medical and coronary ICUs of a university-based medical center were prospectively followed during their ICU admission for delirium with the Confusion Assessment Method for the ICU. Additionally, demographic data were obtained and severity of illness was measured with the APACHE II (Acute Physiology and Chronic Health Evaluation II) score. Six months after discharge, patients were screened for PTSD symptoms by means of the Post-Traumatic Stress Syndrome 10-Questions Inventory (PTSS-10). Multiple linear regression was used to assess the association of potential risk factors with PTSS-10 scores.

Results

At follow-up, six (14%) patients had high levels of PTSD symptoms. On multivariable analysis, women had higher PTSS-10 scores than men by a margin of 7.36 points (95% confidence interval [CI] 1.62 to 13.11; p = 0.02). Also, high levels of PTSD symptoms were less likely to occur in older patients, with symptoms declining after age 50 (p = 0.04). Finally, although causation cannot be assumed, the total dose of lorazepam received during the ICU stay was associated with PTSD symptoms; for every 10-mg increase in cumulative lorazepam dose, PTSS-10 score increased by 0.39 (95% CI 0.17 to 0.61; p = 0.04). No significant relationship was noted between severity of illness and PTSD symptoms or duration of delirium and PTSD symptoms.

Conclusion

High levels of PTSD symptoms occurred in 14% of patients six months following critical illness necessitating mechanical ventilation, and these symptoms were most likely to occur in female patients and those receiving high doses of lorazepam. High levels of PTSD symptoms were less likely to occur in older patients.