Epidemiology of pain, delirium, psychiatric disorders, discomfort and sedation-analgesia management in the intensive care unit: a one-day nationwide study

Abstract

Background: The administration of sedatives and analgesics in intensive care units (ICUs) has evolved significantly over the past 20 years, shifting from deep to light sedation strategies to minimize adverse effects. Despite this shift, substantial variability persists in sedation-analgesia practices. This study aimed to provide an updated national overview of sedation-analgesia management with a focus on discomfort assessment practices, including pain, delirium, anxiety, thirst, mood, and sleep disorders.

Methods: This was a one-day, multicenter, cross-sectional study conducted in French ICUs. Data were collected from all adult patients hospitalized in the ICU on the study day. A Unit-level survey documented ICU characteristics and sedation-analgesia protocols. Patient-level data included sedation levels, pain scores, and assessments of discomfort conditions. Statistical analyses were performed using descriptive methods and multilevel logistic regression.

Results: Among 258 French ICUs contacted, 128 units (50%) participated, enrolling 2,063 patients. Most ICUs were university-affiliated (54%) and mixed medical-surgical (58%); 63% had a written protocol for sedation-analgesia. Sedation and pain were assessed in 96% and 91% of ICUs, respectively. Light or no sedation was observed in 84% of patients, while 15% were deeply sedated - 63% of whom were misaligned with usual indications. Pain assessment was performed at rest in 90% of patients and during care in 62%. Pain prevalence increased with lighter sedation levels and during care. Hypnotics were used in 31% of patients, Mainly propofol and midazolam. Discomfort was reported in 44% of patients, mainly anxiety, sleep disorders, and thirst. Written protocols for sedation and analgesia were not associated with sedation depth, drug use, or delirium screening, but were linked to more frequent pain assessment at rest. Multivariable analyses showed that higher SOFA scores were associated with deep or misaligned deep sedation. The presence of a written protocol for sedation and analgesia reduced the risk of unassessed pain but was not associated with deep or misaligned deep sedation.

Conclusion: The shift toward lighter sedation has been successfully achieved; however, a broad spectrum of stressful symptoms persists, including pain, anxiety, thirst, and sleep disruption. These findings underscore the need for more effective strategies to optimize pain and overall patient comfort in non-deeply sedated ICU patients.

Keywords: Analgesia; Critical care; Delirium; Discomfort; Sedation.

Fig. 1

Sedation levels and pain assessment in intensive care units. This figure presents an alluvial plot illustrating patient trajectories across three key domains: sedation level (“Deep sedation” vs. “Light or no sedation”), pain at rest (“Yes,” “No,” “No evaluation”), and pain during care (“Yes,” “No,” “No evaluation”). Each flow represents a group of patients transitioning between these stages, with stream width proportional to the number of individuals. Dark green indicates patients who experienced pain, light green those without pain, and gray represents cases with no assessment. Patients with agitation, accounting for 1% of the whole cohort, were excluded from the figure for clarity. However, these patients exhibited the highest prevalence of pain (25.0% at rest and 33.3% during care). Pain at rest was more frequently reported in patients with “Light or no sedation” (13%) compared to those under “Deep sedation” (2%). A substantial proportion of patients did not undergo pain assessment at rest, particularly in the deeply sedated group (23% vs. 8% in the lightly or non-sedated group). Missing assessments were even more frequent for pain during care, with no evaluation recorded in 38% of all patients. These findings underscore significant gaps in routine pain monitoring, especially among deeply sedated patients and during nursing or procedural care

Fig. 2

Trajectory of Sedation Levels Throughout Hospitalization. Proportion of patients in each sedation category (agitation, light or no sedation, deep sedation) according to the duration of hospital stay. Sedation levels are expressed as percentages per time interval since admission

Fig. 3

Relationship between sedation and standardized pain depending on the time of assessment. Standardized pain levels according to sedation depth and timing of pain assessment (at rest vs. at care). Patients were classified into four categories: deep sedation (sedation and equivalent RASS ≤ −3), light sedation (sedation and equivalent RASS −2 to + 1), no sedation (no sedation and equivalent RASS −2 to + 1), and agitation (equivalent RASS ≥ + 2). All pain assessment tools were standardized on a 0–10 scale for comparison. Painful patients were defined as those with a standardized pain score above 3/10. Pain was reported in 13% (241/1,855) of patients at rest and in 24% (299/1,272) during care. The percentages at the top of the figure represent the proportion of patients experiencing pain at rest (blue) and during care (red). The proportion of painful patients was higher during care compared to rest, particularly in non-sedated patients (deep sedation: 0.9% vs. 3.3%, p = 0.12; light sedation: 4.3% vs. 9.2%, p = 0.072; no sedation: 15.0% vs. 25.5%, p < 0.001; agitation: 25.0% vs. 33.3%, p = 0.70). Sedation level significantly influenced pain, with an inverse relationship between sedation depth and the proportion of painful patients. At rest, the prevalence of pain was 0.9%, 4.3%, 15.0%, and 25.0% in patients with deep sedation, light sedation, no sedation, and agitation, respectively (p < 0.001). During care, these proportions increased to 3.3%, 9.2%, 25.5%, and 33.3%, respectively (p < 0.001)

Fig. 4

Prevalence of discomfort in intensive care (ICU). A. The upper bar chart illustrates the distribution of patients based on the presence of discomfort. Among them, 33% reported no discomfort, 44% experienced at least one discomfort, and 23% were not assessable. The lower bar chart provides a breakdown of the number of discomforts among patients who reported at least one: 49% experienced a single discomfort (light mauve blue), 33% had two (dark mauve blue), 14% had three (light blue), and 4% reported four discomforts (navy blue). B. The prevalence of discomfort is presented using an upset plot based on an inclusive intersection representation. In this plot, dark dots indicate the presence of a symptom, while light gray dots indicate its absence. When a patient exhibits multiple symptoms, the corresponding dark dots are connected by a continuous dark line. Additionally, a bar plot illustrates the prevalence of each discomfort, with the corresponding percentage indicated above each bar. For clarity, only single-discomfort and two-discomfort combinations are displayed (all possible combinations are detailed in Figure S3). This inclusive intersection approach ensures that the reported percentages reflect the proportion of patients, among patients currently hospitalized in the unit, presenting with at least one symptom or a specific combination of symptoms. A total of 23% of ICU patients were not assessable (first gray bar) and 33% exhibited no discomfort (golden bar). Subsequent bars report the prevalence of patients with a single symptom (light mauve blue bar) and those with a combination of two symptoms (dark mauve blue bar). Among the discomfort symptoms, anxiety was most frequently observed, followed by sleep disturbances and thirst, with the most common combination being anxiety paired with sleep disturbances and, subsequently, anxiety with mood disorders