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What came first, the chicken or the egg? Clinicians sometimes use this ancient Greek paradox to describe the problem of cause-and-effect in long-term impairments of survivors of critical illness—especially with regard to mental health disorders. What is evident is that surviving critical illness is associated with negative effects on cognition, mobility, and mental health; what has become known as Post-Intensive Care Syndrome (PICS). [1] Functional outcomes have become a fundamental patient-centered component of life-sustaining treatment success as functional decline is an unacceptable treatment price for many patients. [2] Understanding associations between psychiatric morbidity and critical illness is a vital step in developing interventions to optimize outcomes after critical illness.

Existing systematic reviews of critical illness survivors suggest that clinically significant symptoms of post-traumatic stress, depression, and anxiety are, respectively, seen in 20%, 30%, and 35% of survivors. [3,4,5,6] Unsurprisingly, psychiatric morbidity prior to critical illness has emerged as one predictor of subsequent mental disorders and symptoms. [7] However, the understanding of prevalence and causal associations of mental disorders and critical illness remains limited by available research.

A core challenge in this research is establishing accurate mental health baselines preceding acute, unplanned intensive care unit (ICU) hospitalizations. Even in large well-controlled trials, investigators struggle to accurately estimate the pre-admission status of their participants. Pre-morbid mental health and functional abilities are typically obtained through third-party assessment in prospective trials. The frailty assessment from Brummel and colleague’s work on functional outcome is one successful example. [8] In the ideal world, the assessment is performed by a proxy that has close contact to the patient, but reality often looks different. The resulting data are to be considered an estimate rather than a precise measurement.

In this issue of Intensive Care Medicine, Olafson and colleagues present a large population-based retrospective study of nearly 50,000 ICU patients examining treatment for mental disorders in the 5 years prior to and following critical illness. Treated prevalence of mental disorders before and after critical illness was compared with cohorts of non-ICU hospitalized patients and the general population. For the ICU patients, in the 5 years following critical illness, there was significant increase in treated prevalence of mental disorders from the 5 years prior, and compared to both cohorts. [9]

Most studies of mental health after critical illness utilize public health registries which opens them to various sources of bias, namely, quality of coding, underreporting of key outcomes, incorrect diagnoses, and misclassification. The use of treated prevalence, however, reflects care reality in “real-life” and it is no exaggeration to describe the documented prevalence of mental disorders described by Olafson and colleagues as catastrophic. An important caveat is that the data only reflect the situation in one Canadian province and absolute values cannot be generalized, but it should at least encourage clinical researchers to repeat this analysis in their own context.

The episodic nature of many mental disorders makes the extended 5-year period design especially strong. Considering Olafson’s data, mental disorders are dynamic and treated prevalence changes in the 5 years prior to ICU admission nearly as much as post-discharge. There is an increased prevalence of mental disorders before and after critical illness, which dovetails with findings from previous studies—the prevalence varies, but the data consistently show this signal. [10]

What is also unique about the work is that the authors did not limit their assessment to mood and anxiety disorders (including the comparably well-studied PTSD), but extended their research to treatment of other mental disorders, including psychosis and substance-induced disorders. For future studies, this is extremely valuable as it extends the scope of mental health outcomes. The findings of this restrospective analysis show a demand for prospective studies to quantify and assess post-index admission outcomes in survivors of critical illness. To achieve this, we need to further implement core outcome measurement sets for PICS. [11]

For patients, the most important question might be if they have access to care and adequate critical care survivor therapy. This remains a true challenge for the future and is likely an unmet demand. Despite critical care being an interdisciplinary and multi-professional subject in the acute phase, critical care personnel (i.e., physicians and nurses) are usually cut off from subsequent healthcare. While ICU follow-up clinics do exist in some care models (e.g., United Kingdom), the majority of critical care survivors do not have access to ICU follow-up clinics  [12,13,14]. PICS awareness in outpatient care has probably increased due to the coronavirus disease 2019 (COVID-19) pandemic and long-haul COVID-19. [15] While there is a greater scientific focus on specific COVID-19 consequences, Olafson’s work shows that long-term mental health consequences are not a COVID-19-specific phenomenon at all. In addition, one observes that mortality after initial survival is extremely high, as nearly half of the cohort perished before follow-up time completion. The reduction in mental health burden over time might simply be the sad result of the high mortality.

In summary, Olafson and colleagues’ study shows that mental health is a highly relevant topic in the context of intensive care. It is not so much about the “chicken or the egg,” as it is the sheer magnitude of the problem and, consequently, need for prevention and intervention to ensure adequate care. We need a better understanding of the trajectory of mental health in the context of critical illness. To achieve better understanding, we must collaborate to (1) advocate and support a clinical follow-up for all ICU patients, (2) invest in further research, and (3) bolster awareness through education initiatives. Finally, intensive care is not only a matter of life and death but also of quality of life and adequate care for our patients. This paper requires us to focus more on mental health outcomes moving forward.


       是先有雞還是先有蛋?臨床醫生有時會用這個古希臘悖論來描述危重病人長期損傷的因果關係問題,特別是在心理健康障礙方面。顯而易見的是,危重病人的生存與認知、活動能力和心理健康的負面影響有關;這就是所謂的重症監護後綜合症(PICS)。[1]功能結果已經成為維持生命治療成功的以病人為中心的基本組成部分,因為功能下降對許多病人來説是不可接受的治療代價。[2] 了解精神病發病率和危重病之間的關聯是制定干預措施以優化危重病後的結果的重要一步。

現有的對危重病倖存者的系統回顧表明,臨床上顯著的創傷後壓力、抑鬱和焦慮症狀分別見於20%、30%和35%的倖存者。[3,4,5,6] 不足為奇的是,危重病人之前的精神病發病率已經成為後來精神障礙和症狀的預測因素之一。[7]然而,現有的研究對精神障礙和危重病的發病率和因果關係的理解仍然有限。



       大多數關於危重病後心理健康的研究都是利用公共衛生登記冊,這使他們面臨各種偏差來源,即編碼品質、關鍵結果的漏報、錯誤的診斷和錯誤的分類。然而,使用處理後的流行率反映了 "現實生活 "中的護理現實,將Olafson及其同事所描述的精神障礙的記錄流行率描述為災難性的並不誇張。一個重要的警告是,這些數據只反映了加拿大一個省的情況,絕對值不能一概而論,但它至少應該鼓勵臨床研究人員在自己的環境中重復這種分析。



       對於病人來説,最重要的問題可能是他們是否能獲得護理和足夠的重症監護倖存者治療。這仍然是未來的一個真正的挑戰,而且很可能是未滿足的需求。儘管危重症護理在急性期是一個跨學科和多專業的課題,但危重症護理人員(即醫生和護士)通常與後續的醫療服務隔絕。雖然在一些護理模式中確實存在ICU後續診所(如英國),但大多數危重病人沒有機會進入ICU後續診所[12,13,14]。由於2019年冠狀病毒病(COVID-19)大流行和長途COVID-19,門診護理中的PICS意識可能已經增強。[15] 雖然科學界更多關注的是特定的COVID-19後果,但Olafson的工作表明,長期的心理健康後果根本不是COVID-19特定的現象。此外,人們觀察到,初始生存後的死亡率極高,因為近一半的隊列在隨訪時間完成前就已殞命。隨著時間的推移,心理健康負擔的減少可能只是高死亡率的可悲結果。

總之,Olafson及其同事的研究表明,在重症監護方面,心理健康是一個高度相關的話題。與其説是 "先有雞還是先有蛋",不如説是問題的嚴重性,因此需要進行預防和干預以確保充分的護理。我們需要更好地了解危重疾病背景下的心理健康軌跡。為了達到更好的理解,我們必須合作:(1)倡導和支援對所有ICU病人進行臨床隨訪,(2)投資于進一步的研究,以及(3)通過教育活動加強認識。最後,重症監護不僅關係到生命和死亡,也關係到我們病人的生活品質和充分的護理。本文要求我們在今後的工作中更加關注心理健康的結果。