Do sedation and analgesia contribute to long-term cognitive dysfunction in critical care survivors?

Long-term neurocognitive outcomes after pediatric intensive care: exploring the role of drug exposure

BACKGROUND

Concerns exist regarding the impact of widely used clinical drugs on brain development. This study investigates long-term neurocognitive functioning in relation to frequently used drug exposure at the Pediatric Intensive Care Unit (PICU).

METHODS

This study compared children aged 6-12 years with previous PICU admission (age ≤1 year) for bronchiolitis requiring mechanical ventilation (patient group, n = 65) to a demographically comparable control group (n = 76) on a broad range of neurocognitive outcomes. The patient group was selected because bronchiolitis seldom manifests neurologically and is therefore not expected to affect neurocognitive functioning in itself. The relation between exposure to sedatives, analgesics and anesthetics and neurocognitive outcomes was assessed by regression analyses.

RESULTS

The patient group had lower intelligence than the control group (p < 0.001, d = -0.59) and poorer performance in neurocognitive functions; i.e., speed and attention (p = 0.03, d = -0.41) and verbal memory (p < 0.001, d = -0.60). Exposure to sedatives, analgesics and anesthetics was not related to neurocognitive outcomes.

CONCLUSIONS

Children with PICU admission for bronchiolitis requiring mechanical ventilation are at risk of adverse neurocognitive outcomes. This study found no evidence for a role of exposure to sedatives, analgesics or anesthetics. Findings underline the importance of long-term follow-up after PICU admission, even in the absence of disease with neurological manifestation.

IMPACT

Animal studies have indicated that exposing the maturing brain to clinical drugs may cause neurodegeneration. Clinical studies show mixed evidence regarding the association between clinical drugs and neurocognitive outcomes. This study provides evidence for considerably lower neurocognitive functioning among children with a history of PICU admission for bronchiolitis compared to healthy peers. Bronchiolitis seldom manifests neurologically and is therefore not expected to affect neurocognitive functioning in itself. We found no evidence supporting a relation between drug exposure (i.e., sedatives, analgesics and anesthetics) and long-term neurocognitive outcomes. Findings underline the importance of structured follow-up after PICU admission.

Intensive Care Unit-Specific Virtual Reality for Critically Ill Patients With COVID-19: Multicenter Randomized Controlled Trial

Background

Although psychological sequelae after intensive care unit (ICU) treatment are considered quite intrusive, robustly effective interventions to treat or prevent these long-term sequelae are lacking. Recently, it was demonstrated that ICU-specific virtual reality (ICU-VR) is a feasible and acceptable intervention with potential mental health benefits. However, its effect on mental health and ICU aftercare in COVID-19 ICU survivors is unknown.

Objective

This study aimed to explore the effects of ICU-VR on mental health and on patients’ perceived quality of, satisfaction with, and rating of ICU aftercare among COVID-19 ICU survivors.

Methods

This was a multicenter randomized controlled trial. Patients were randomized to either the ICU-VR (intervention) or the control group. All patients were invited to an COVID-19 post-ICU follow-up clinic 3 months after hospital discharge, during which patients in the intervention group received ICU-VR. One month and 3 months later (4 and 6 months after hospital discharge), mental health, quality of life, perceived quality, satisfaction with, and rating of ICU aftercare were scored using questionnaires.

Results

Eighty-nine patients (median age 58 years; 63 males, 70%) were included. The prevalence and severity of psychological distress were limited throughout follow-up, and no differences in psychological distress or quality of life were observed between the groups. ICU-VR improved satisfaction with (mean score 8.7, SD 1.6 vs 7.6, SD 1.6 [ICU-VR vs control]; t₆₄=–2.82, P=.006) and overall rating of ICU aftercare (mean overall rating of aftercare 8.9, SD 0.9 vs 7.8, SD 1.7 [ICU-VR vs control]; t₆₄=–3.25; P=.002) compared to controls. ICU-VR added to the quality of ICU aftercare according to 81% of the patients, and all patients would recommend ICU-VR to other ICU survivors.

Conclusions

ICU-VR is a feasible and acceptable innovative method to improve satisfaction with and rating of ICU aftercare and adds to its perceived quality. We observed a low prevalence of psychological distress after ICU treatment for COVID-19, and ICU-VR did not improve psychological recovery or quality of life. Future research is needed to confirm our results in other critical illness survivors to potentially facilitate ICU-VR’s widespread availability and application during follow-up.

Trial Registration

Netherlands Trial Register NL8835; https://www.trialregister.nl/trial/8835

International Registered Report Identifier (IRRID)

RR2-10.1186/s13063-021-05271-z

Virtual Reality-Based Early Neurocognitive Stimulation in Critically Ill Patients: A Pilot Randomized Clinical Trial

This study focuses on the application of a non-immersive virtual reality (VR)-based neurocognitive intervention in critically ill patients. Our aim was to assess the feasibility of direct outcome measures to detect the impact of this digital therapy on patients’ cognitive and emotional outcomes. Seventy-two mechanically ventilated adult patients were randomly assigned to the “treatment as usual” (TAU, n = 38) or the “early neurocognitive stimulation” (ENRIC, n = 34) groups. All patients received standard intensive care unit (ICU) care. Patients in the ENRIC group also received adjuvant neurocognitive stimulation during the ICU stay. Outcome measures were a full neuropsychological battery and two mental health questionnaires. A total of 42 patients (21 ENRIC) completed assessment one month after ICU discharge, and 24 (10 ENRIC) one year later. At one-month follow-up, ENRIC patients had better working memory scores (p = 0.009, d = 0.363) and showed up to 50% less non-specific anxiety (11.8% vs. 21.1%) and depression (5.9% vs. 10.5%) than TAU patients. A general linear model of repeated measures reported a main effect of group, but not of time or group–time interaction, on working memory, with ENRIC patients outperforming TAU patients (p = 0.008, η_p² = 0.282). Our results suggest that non-immersive VR-based neurocognitive stimulation may help improve short-term working memory outcomes in survivors of critical illness. Moreover, this advantage could be maintained in the long term. An efficacy trial in a larger sample of participants is feasible and must be conducted.

Psychologic Distress and Quality of Life After ICU Treatment for Coronavirus Disease 2019: A Multicenter, Observational Cohort Study

Supplemental Digital Content is available in the text.

OBJECTIVES:

To quantify short- and long-term psychologic distress, that is, symptoms of posttraumatic stress disorder, anxiety, and depression, and the health-related quality of life in coronavirus disease 2019 ICU survivors.

DESIGN:

A prospective, observational cohort study.

SETTING:

Postcoronavirus disease 2019 clinics of three hospitals in Rotterdam, the Netherlands.

PATIENTS:

Adult patients admitted for coronavirus disease 2019 to the ICU, who visited the postcoronavirus disease 2019 follow-up clinic.

MEASURES AND MAIN RESULTS:

The primary outcomes were psychologic distress and overall and mental health-related quality of life, assessed using the Impact of Event Scale-Revised, Hospital Anxiety and Depression Scale, Short-Form 36, and European Quality of Life 5D, 6 weeks, 3 months, and 6 months post hospital discharge. Second, we compared 3-month psychologic and mental health-related quality of life outcomes with a historical critical illness survivor cohort and overall and mental health-related quality of life with the Dutch population. We included 118 patients with a median age of 61 years (95% range, 36–77 yr) of whom 79 (68%) were male. At 6 weeks, 13 patients (23%) reported psychologic distress, copresence of probable psychiatric disorders was common, and no decline in psychologic distress was observed throughout follow-up. Coronavirus disease 2019 patients tend to suffer less from posttraumatic stress disorder and reported less severe symptoms of anxiety (Hospital Anxiety and Depression Scale Anxiety Score: 3 [0–17] vs 5 [0–16]; estimated mean difference 2.3 [95% CI, 0.0–4.7]; p = 0.05) and depression (Hospital Anxiety and Depression Scale Depression Score: 3 [0–15] vs 5 [0–16]; estimated mean difference 2.4 [95% CI, 0.1–2.4]; p = 0.04) than the historical critical illness cohort. Overall and mental health-related quality of life increased over time. Coronavirus disease 2019 ICU survivors reported better mental health-related quality of life than our historical cohort, but overall and mental health-related quality of life was still poorer than the Dutch population.

CONCLUSIONS:

Psychologic distress was common in coronavirus disease 2019 ICU survivors and remained similar until 6 months after hospital discharge. Health-related quality of life increased over time and was higher than in a historical cohort, but was lower than in the Dutch population. Our findings highlight that coronavirus disease 2019 ICU survivors should be monitored after ICU treatment to detect possible psychologic distress.

Individual recovery of health-related quality of life during 18 months post-burn using a retrospective pre-burn measurement: an exploratory study

Purpose

This study explored the individual trajectories of health-related quality of life (HRQL) compared to recalled pre-burn level of HRQL and investigated whether burn severity and post-traumatic stress disorder (PTSD) symptoms increase the risk of not returning to pre-burn level of HRQL.

Methods

Data were obtained from 309 adult patients with burns in a multicenter study. Patients completed the EQ-5D-3L questionnaire with a Cognition bolt-on shortly after hospital admission, which included a recalled pre-injury measure, and, again, at 3, 6, 12 and 18 months post-burn. Burn severity was indicated by the number of surgeries, and PTSD symptoms were assessed with the IES-R at three months post-burn. Pre- and post-injury HRQL were compared to norm populations.

Results

Recalled pre-injury HRQL was higher than population norms and HRQL at 18 months post-burn was comparable to population norms. Compared to the pre-injury level of functioning, four HRQL patterns of change over time were established: Stable, Recovery, Deterioration, and Growth. In each HRQL domain, a subset of patients did not return to their recalled pre-injury levels, especially with regard to Pain, Anxiety/Depression, and Cognition. Patients with more severe burns or PTSD symptoms were less likely to return to pre-injury level of functioning within 18 months post-burn.

Conclusion

This study identified four patterns of individual change. Patients with more severe injuries and PTSD symptoms were more at risk of not returning to their recalled pre-injury HRQL. This study supports the face validity of using a recalled pre-burn HRQL score as a reference point to monitor HRQL after burns.

Electronic supplementary material

The online version of this article (10.1007/s11136-020-02678-0) contains supplementary material, which is available to authorized users.

Cognitive phenotypes 1 month after ICU discharge in mechanically ventilated patients: a prospective observational cohort study

BACKGROUND

ICU patients undergoing invasive mechanical ventilation experience cognitive decline associated with their critical illness and its management. The early detection of different cognitive phenotypes might reveal the involvement of diverse pathophysiological mechanisms and help to clarify the role of the precipitating and predisposing factors. Our main objective is to identify cognitive phenotypes in critically ill survivors 1 month after ICU discharge using an unsupervised machine learning method, and to contrast them with the classical approach of cognitive impairment assessment. For descriptive purposes, precipitating and predisposing factors for cognitive impairment were explored.

METHODS

A total of 156 mechanically ventilated critically ill patients from two medical/surgical ICUs were prospectively studied. Patients with previous cognitive impairment, neurological or psychiatric diagnosis were excluded. Clinical variables were registered during ICU stay, and 100 patients were cognitively assessed 1 month after ICU discharge. The unsupervised machine learning K-means clustering algorithm was applied to detect cognitive phenotypes. Exploratory analyses were used to study precipitating and predisposing factors for cognitive impairment.

RESULTS

K-means testing identified three clusters (K) of patients with different cognitive phenotypes: K1 (n = 13), severe cognitive impairment in speed of processing (92%) and executive function (85%); K2 (n = 33), moderate-to-severe deficits in learning-memory (55%), memory retrieval (67%), speed of processing (36.4%) and executive function (33.3%); and K3 (n = 46), normal cognitive profile in 89% of patients. Using the classical approach, moderate-to-severe cognitive decline was recorded in 47% of patients, while the K-means method accurately classified 85.9%. The descriptive analysis showed significant differences in days (p = 0.016) and doses (p = 0.039) with opioid treatment in K1 vs. K2 and K3. In K2, there were more women, patients were older and had more comorbidities (p = 0.001) than in K1 or K3. Cognitive reserve was significantly (p = 0.001) higher in K3 than in K1 or K2.

CONCLUSION

One month after ICU discharge, three groups of patients with different cognitive phenotypes were identified through an unsupervised machine learning method. This novel approach improved the classical classification of cognitive impairment in ICU survivors. In the exploratory analysis, gender, age and the level of cognitive reserve emerged as relevant predisposing factors for cognitive impairment in ICU patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier:NCT02390024; March 17,2015.

Long-term cognitive impairment after ICU treatment: a prospective longitudinal cohort study (Cog-I-CU)

In this prospective cohort study we aimed to investigate the trajectory of the cognitive performance of patients after discharge from an intensive care unit (ICU). Special consideration was given to patients with suspected premorbid cognitive impairment who might be at risk for the development of dementia. Clinical characteristics were collected until discharge. The premorbid cognitive state was estimated by a structured interview with a close relative. Cognitive outcome was assessed using the Consortium to Establish a Registry of Alzheimer’s Disease (CERAD) Plus battery and the Stroop Color and Word Test at the time of discharge from ICU and 9 months later. The results of the study group were compared to an established healthy control group and to normative data. A total number of 108 patients were finally included. At the time of discharge, patients underperformed the healthy control group. In linear regression models, delirium during the ICU stay and the factor premorbid cognitive impairment were associated with poorer cognitive outcome (p = 0.047 and p = 0.001). After 9 months, in 6% of patients without evidence of premorbid cognitive impairment long-lasting deficits were found. In patients with suspected premorbid cognitive impairment, performance in tests of executive function failed to improve.

Effect of Personalized Music Intervention in Mechanically Ventilated Children in the PICU: A Pilot Study

OBJECTIVES

To determine the feasibility of a personalized music intervention with mechanically ventilated patients in the PICU.

DESIGN

Pilot study with a quasi-experimental design.

SETTING

Tertiary children's hospital in China with a 40-bed PICU.

PATIENTS

Children, 1 month to 7 years, with mechanical ventilation were recruited and assigned to music group (n = 25) and control group (n = 25).

INTERVENTIONS

Children in the music group received their own favorite music and listened for 60 minutes three times a day. The control group receive routine care without music.

MEASUREMENTS AND MAIN RESULTS

Primary outcome measure was comfort measured with the COMFORT Behavior scale 5 minutes before and after the music. Secondary outcome measures were physiologic variables; heart rate, respiration, blood pressure, oxygen saturation. Mechanical ventilation time, length of stay, and sedation medication were also collected. Qualitative analysis revealed that nurses had a positive attitude in delivering the interventions and identified improvements for the main trial. Children in the music group had lower COMFORT Behavior scores (15.7 vs 17.6; p = 0.011). Children in the music group had better physiologic outcomes; heart rate (140 vs 144; p = 0.039), respiration rate (40 vs 43; p = 0.036), systolic blood pressure (93 vs 95 mm Hg; p = 0.031), oxygen saturation (96% vs 95%; p < 0.001), diastolic blood pressure was not significantly (52 vs 53 mm Hg; p = 0.11). Children in the music group had a shorter ventilation time (148.7 vs 187.6; p = 0.044) and a shorter length of stay, but not significant (11.2 vs 13.8; p = 0.071). Children in the control group had higher total amount of on-demand midazolam (29 vs 33 mg; p = 0.040).

CONCLUSIONS

Our pilot study indicates that personalized music intervention is feasible and might improve the comfort of children with mechanical ventilation. Further studies are needed to provide conclusive evidence in confirming the effectiveness of music interventions comforting critically ill children in PICUs.

Double Cycling During Mechanical Ventilation: Frequency, Mechanisms, and Physiologic Implications

OBJECTIVES

Double cycling generates larger than expected tidal volumes that contribute to lung injury. We analyzed the incidence, mechanisms, and physiologic implications of double cycling during volume- and pressure-targeted mechanical ventilation in critically ill patients.

DESIGN

Prospective, observational study.

SETTING

Three general ICUs in Spain.

PATIENTS

Sixty-seven continuously monitored adult patients undergoing volume control-continuous mandatory ventilation with constant flow, volume control-continuous mandatory ventilation with decelerated flow, or pressure control-continuous mandatory mechanical ventilation for longer than 24 hours.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We analyzed 9,251 hours of mechanical ventilation corresponding to 9,694,573 breaths. Double cycling occurred in 0.6%. All patients had double cycling; however, the distribution of double cycling varied over time. The mean percentage (95% CI) of double cycling was higher in pressure control-continuous mandatory ventilation 0.54 (0.34-0.87) than in volume control-continuous mandatory ventilation with constant flow 0.27 (0.19-0.38) or volume control-continuous mandatory ventilation with decelerated flow 0.11 (0.06-0.20). Tidal volume in double-cycled breaths was higher in volume control-continuous mandatory ventilation with constant flow and volume control-continuous mandatory ventilation with decelerated flow than in pressure control-continuous mandatory ventilation. Double-cycled breaths were patient triggered in 65.4% and reverse triggered (diaphragmatic contraction stimulated by a previous passive ventilator breath) in 34.6% of cases; the difference was largest in volume control-continuous mandatory ventilation with decelerated flow (80.7% patient triggered and 19.3% reverse triggered). Peak pressure of the second stacked breath was highest in volume control-continuous mandatory ventilation with constant flow regardless of trigger type. Various physiologic factors, none mutually exclusive, were associated with double cycling.

CONCLUSIONS

Double cycling is uncommon but occurs in all patients. Periods without double cycling alternate with periods with clusters of double cycling. The volume of the stacked breaths can double the set tidal volume in volume control-continuous mandatory ventilation with constant flow. Gas delivery must be tailored to neuroventilatory demand because interdependent ventilator setting-related physiologic factors can contribute to double cycling. One third of double-cycled breaths were reverse triggered, suggesting that repeated respiratory muscle activation after time-initiated ventilator breaths occurs more often than expected.

Effects of sedatives and opioids on trigger and cycling asynchronies throughout mechanical ventilation: an observational study in a large dataset from critically ill patients

Background

In critically ill patients, poor patient-ventilator interaction may worsen outcomes. Although sedatives are often administered to improve comfort and facilitate ventilation, they can be deleterious. Whether opioids improve asynchronies with fewer negative effects is unknown. We hypothesized that opioids alone would improve asynchronies and result in more wakeful patients than sedatives alone or sedatives-plus-opioids.

Methods

This prospective multicenter observational trial enrolled critically ill adults mechanically ventilated (MV) > 24 h. We compared asynchronies and sedation depth in patients receiving sedatives, opioids, or both. We recorded sedation level and doses of sedatives and opioids. BetterCare™ software continuously registered ineffective inspiratory efforts during expiration (IEE), double cycling (DC), and asynchrony index (AI) as well as MV modes. All variables were averaged per day. We used linear mixed-effects models to analyze the relationships between asynchronies, sedation level, and sedative and opioid doses.

Results

In 79 patients, 14,166,469 breaths were recorded during 579 days of MV. Overall asynchronies were not significantly different in days classified as sedatives-only, opioids-only, and sedatives-plus-opioids and were more prevalent in days classified as no-drugs than in those classified as sedatives-plus-opioids, irrespective of the ventilatory mode. Sedative doses were associated with sedation level and with reduced DC (p < 0.0001) in sedatives-only days. However, on days classified as sedatives-plus-opioids, higher sedative doses and deeper sedation had more IEE (p < 0.0001) and higher AI (p = 0.0004). Opioid dosing was inversely associated with overall asynchronies (p < 0.001) without worsening sedation levels into morbid ranges.

Conclusions

Sedatives, whether alone or combined with opioids, do not result in better patient-ventilator interaction than opioids alone, in any ventilatory mode. Higher opioid dose (alone or with sedatives) was associated with lower AI without depressing consciousness. Higher sedative doses administered alone were associated only with less DC.

Trial registration

ClinicalTrial.gov, NCT03451461

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2531-5) contains supplementary material, which is available to authorized users.

Mechanisms involved in brain dysfunction in mechanically ventilated critically ill patients: implications and therapeutics

Critical illness may lead to significant long-term neurological morbidity and patients frequently develop neuropsychological disturbances including acute delirium or memory impairment after intensive care unit (ICU) discharge. Mechanical ventilation (MV) is a risk factor to the development of adverse neurocognitive outcomes. Patients undergoing MV for long periods present neurologic impairment with memory and cognitive alteration. Delirium is considered an acute form of brain dysfunction and its prevalence rises in mechanically ventilated patients. Delirium duration is an independent predictor of mortality, ventilation time, ICU length of stay and short- and long-term cognitive impairment in the ICU survivors. Although, neurocognitive sequelae tend to improve after hospital discharge, residual deficits persist even 6 years after ICU stay. ICU-related neurocognitive impairments occurred in many cognitive domains and are particularly pronounced with regard to memory, executive functions, attentional functions, and processing speed. These sequelae have an important impact on patients' lives and ICU survivors often require institutionalization and hospitalization. Experimental studies have served to explore the possible mechanisms or pathways involved in this lung to brain interaction. This communication can be mediated via a complex web of signaling events involving neural, inflammatory, immunologic and neuroendocrine pathways. MV can affect respiratory networks and the application of protective ventilation strategies is mandatory in order to prevent adverse effects. Therefore, strategies focused to minimize lung stretch may improve outcomes, avoiding failure of distal organ, including the brain. Long-term neurocognitive impairments experienced by critically ill survivors may be mitigated by early interventions, combining cognitive and physical therapies. Inpatient rehabilitation interventions in ICU promise to improve outcomes in critically ill patients. The cross-talk between lung and brain, involving specific pathways during critical illness deserves further efforts to evaluate, prevent and improve cognitive alterations after ICU admission, and highlights the crucial importance of tailoring MV to prevent adverse outcomes.

Feasibility and safety of virtual-reality-based early neurocognitive stimulation in critically ill patients

Background

Growing evidence suggests that critical illness often results in significant long-term neurocognitive impairments in one-third of survivors. Although these neurocognitive impairments are long-lasting and devastating for survivors, rehabilitation rarely occurs during or after critical illness. Our aim is to describe an early neurocognitive stimulation intervention based on virtual reality for patients who are critically ill and to present the results of a proof-of-concept study testing the feasibility, safety, and suitability of this intervention.

Methods

Twenty critically ill adult patients undergoing or having undergone mechanical ventilation for ≥24 h received daily 20-min neurocognitive stimulation sessions when awake and alert during their ICU stay. The difficulty of the exercises included in the sessions progressively increased over successive sessions. Physiological data were recorded before, during, and after each session. Safety was assessed through heart rate, peripheral oxygen saturation, and respiratory rate. Heart rate variability analysis, an indirect measure of autonomic activity sensitive to cognitive demands, was used to assess the efficacy of the exercises in stimulating attention and working memory.

Results

Patients successfully completed the sessions on most days. No sessions were stopped early for safety concerns, and no adverse events occurred. Heart rate variability analysis showed that the exercises stimulated attention and working memory. Critically ill patients considered the sessions enjoyable and relaxing without being overly fatiguing.

Conclusions

The results in this proof-of-concept study suggest that a virtual-reality-based neurocognitive intervention is feasible, safe, and tolerable, stimulating cognitive functions and satisfying critically ill patients. Future studies will evaluate the impact of interventions on neurocognitive outcomes.

Trial registration Clinical trials.gov identifier: NCT02078206

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0303-4) contains supplementary material, which is available to authorized users.