A dual-center cohort study on the association between early deep sedation and clinical outcomes in mechanically ventilated patients during the COVID-19 pandemic: The COVID-SED study

Impact of Sedation Practices on Mortality in COVID-19-Associated Adult Respiratory Distress Syndrome Patients: A Multicenter Retrospective Descriptive Study

Background: Reduction in sedation exposure is an important metric in intensive care unit (ICU) patients. However, challenges arose during the coronavirus disease-2019 (COVID-19) pandemic in adhering to this practice, driven by concerns on transmission and disease severity issues. Accordingly, diverse sedation approaches emerged, although the effect on mortality has not been studied thoroughly. Methods: Retrospective cohort study in the medical ICU of seven hospitals within a major Health System in Northeast Ohio. We included all adult patients admitted with COVID-19 requiring invasive mechanical ventilation (IMV) from March 2020 to December 2021. Results: Study included 2394 COVID-19 patients requiring IMV. Across waves, sample included 55-63% male subjects, with an average age of 61-68 years (P < 0.001), Acute Physiologic and Chronic Health Evaluation (APACHE)-III score 65.8-68.9 (P = 0.37), median IMV duration 8-10 days (P = 0.14), and median ICU duration 9.8-11.6 days (P = 0.084). Propofol remained the primary sedative (84-92%; P = 0.089). Ketamine use increased from the first (9.7%) to fourth (19%) wave (P = 0.002). Midazolam use decreased from the first (27.4%) to third (9.4%) wave (P = 0.001). Dexmedetomidine use declined from 35% to 27-28% (P = 0.002) after the first wave. A multivariable regression analysis indicated clinical variables explained 34% of the variation in hospital mortality (R2). Factors associated with higher mortality included age [aOR = 1.059 (95% CI 1.049-1.069); P < 0.001], COVID-19 wave, especially fourth wave [aOR = 2.147, (95% CI 1.370-3.365); P = 0.001], and higher number of vasopressors [aOR = 31.636, (95% CI 17.603-56.856); P < 0.001]. Addition of sedative medications to a second model led to an increase in the R2 by only 1.6% to 35.6% [aOR = 1 (95% CI 1-1); P > 0.05] for propofol, ketamine, and midazolam. Dexmedetomidine demonstrated a decrease in the odds of mortality [aOR = 0.96 (95% CI 0.94-0.97); P < 0.001]. Conclusion: Mortality in critical COVID-19 patients was mostly driven by illness severity, and the choice of sedation might have minimal impact when other factors are controlled.

Early Deep Sedation Practices Worsened During the Pandemic Among Adult Patients Without COVID-19: A Retrospective Cohort Study

BACKGROUND

There is substantial evidence that patients with COVID-19 were treated with sustained deep sedation during the pandemic. However, it is unknown whether such guideline-discordant care had spillover effects to patients without COVID-19.

RESEARCH QUESTION

Did patterns of early deep sedation change during the pandemic for patients on mechanical ventilation without COVID-19?

STUDY DESIGN AND METHODS

We used electronic health record data from 4,237 patients who were intubated without COVID-19. We compared sedation practices in the first 48 h after intubation across prepandemic (February 1, 2018, to January 31, 2020), pandemic (April 1, 2020, to March 31, 2021), and late pandemic (April 1, 2021, to March 31, 2022) periods.

RESULTS

In the prepandemic period, patients spent an average of 13.0 h deeply sedated in the first 48 h after intubation. This increased 1.9 h (95% CI, 1.0-2.8) during the pandemic period and 2.9 h (95% CI, 2.0-3.8) in the late pandemic period. The proportion of patients that spent over one-half of the first 48 h deeply sedated was 18.9% in the prepandemic period, 22.3% during the pandemic period, and 25.9% during the late pandemic period. Ventilator-free days decreased during the pandemic, with a subdistribution hazard ratio of being alive without mechanical ventilation at 28 days of 0.87 (95% CI, 0.79-0.95) compared with the prepandemic period. Tracheostomy placement increased during the pandemic period compared with the prepandemic period (OR, 1.41; 95% CI, 1.08-1.82). In the medical ICU, early deep sedation increased 2.5 h (95% CI, 0.6-4.4) during the pandemic period and 4.9 h (95% CI, 3.0-6.9) during the late pandemic period, compared with the prepandemic period.

INTERPRETATION

We found that among patients on mechanical ventilation without COVID-19, sedation use increased during the pandemic. In the subsequent year, these practices did not return to prepandemic standards.

Correlation of Sedation Depth During Critical Care Transport and Hospitalization

Purpose: We aim to assess the impact of the exposure to deep versus light sedation by a critical care transport agency during prehospital and interhospital transport on hospital sedation levels, medication exposure, and outcomes of mechanically ventilated patients. Materials and Methods: Retrospective cohort review of mechanically ventilated adult critical care transport patients from January 1, 2019, to March 11, 2020, who arrived at an academic medical center. The primary outcome was the correlation of deep sedation during transport with deep sedation within the first 48 h of hospitalization (defined as Richmond Agitation Sedation Scale [RASS] -3 to -5). The secondary outcomes were duration of mechanical ventilation, hospital length of stay, intensive care unit (ICU) length of stay, inpatient mortality, delirium within 48 h, and coma within 48 h. Results: One hundred and ninety-eight patients were included, of whom 183 (92.4%) were deeply sedated during transport which persisted through the first 48 h of hospital care. Deep sedation during transport was not correlated with deep sedation in the hospital within the first 48 h (OR 2.41; 95% CI, 0.48-12.02). There was no correlation with hospital length of stay, ICU length of stay, duration of mechanical ventilation, or hospital mortality. Deep sedation during transport was not correlated with delirium or coma within the first 48 h of hospitalization. There was a negligible correlation between final transport RASS and initial hospital RASS which did not differ based on the lapsed time from handoff (<1 h corr. coeff. 0.23; ≥1 h corr. coeff. 0.25). Conclusions: Deep sedation was observed during critical care transport in this cohort and was not correlated with deep sedation during the first 48 h of hospitalization. The transition of care between the transport team and the hospital team may be an opportunity to disrupt therapeutic momentum and re-evaluate sedation decisions.

Inhaled volatile anesthetics in the intensive care unit

The discovery and utilization of volatile anesthetics has significantly transformed surgical practices since their inception in the mid-19th century. Recently, a paradigm shift is observed as volatile anesthetics extend beyond traditional confines of the operating theatres, finding diverse applications in intensive care settings. In the dynamic landscape of intensive care, volatile anesthetics emerge as a promising avenue for addressing complex sedation requirements, managing refractory lung pathologies including acute respiratory distress syndrome and status asthmaticus, conditions of high sedative requirements including burns, high opioid or alcohol use and neurological conditions such as status epilepticus. Volatile anesthetics can be administered through either inhaled route via anesthetic machines/devices or through extracorporeal membrane oxygenation circuitry, providing intensivists with multiple options to tailor therapy. Furthermore, their unique pharmacokinetic profiles render them titratable and empower clinicians to individualize management with heightened accuracy, mitigating risks associated with conventional sedation modalities. Despite the amounting enthusiasm for the use of these therapies, barriers to widespread utilization include expanding equipment availability, staff familiarity and training of safe use. This article delves into the realm of applying inhaled volatile anesthetics in the intensive care unit through discussing their pharmacology, administration considerations in intensive care settings, complication considerations, and listing indications and evidence of the use of volatile anesthetics in the critically ill patient population.

Sedation Practices of Mechanically Ventilated Patients During Critical Care Transport

OBJECTIVE

Mechanically ventilated patients who receive deep levels of sedation have high mortality rates, longer lengths of stay, and longer duration of mechanical ventilation in the intensive care unit. Prior literature demonstrated a high frequency of deep sedation across all levels of care. Benzodiazepines have been attributed to similar morbidity and mortality findings.

METHODS

This study was a descriptive retrospective review of mechanically ventilated adult critical care transport patients from January 1, 2019, to March 11, 2020. Our primary outcome was the percentage of patients who were deeply sedated at handoff to the receiving facility. Deep sedation was defined as a Richmond Agitation Sedation Scale of -3 to -5. Our secondary outcomes were the percentage of patients who received benzodiazepines; the number of unplanned extubations, crew injuries, and unsafe patient care situations; and the incidence of ventilator dyssynchrony.

RESULTS

Five hundred fifty-three mechanically ventilated patients were transported. Ninety-three patients were excluded because they received paralytics during transport. Four hundred sixty patients were included in the analysis, 422 (91.7%) of whom were deeply sedated. Benzodiazepines were administered to 141 patients (30.6%). There were no differences observed in the secondary outcomes.

CONCLUSION

Deep sedation and benzodiazepine administration were frequent during critical care transport of mechanically ventilated patients.

Characteristics of delirium and its association with sedation and in-hospital mortality in patients with COVID-19 on veno-venous extracorporeal membrane oxygenation

Background

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) has been used in patients with COVID-19 acute respiratory distress syndrome (ARDS). We aim to assess the characteristics of delirium and describe its association with sedation and in-hospital mortality.

Methods

We retrospectively reviewed adult patients on VV-ECMO for severe COVID-19 ARDS in the Johns Hopkins Hospital ECMO registry in 2020-2021. Delirium was assessed by the Confusion Assessment Method for the ICU (CAM-ICU) when patients scored-3 or above on the Richmond Agitation-Sedation Scale (RASS). Primary outcomes were delirium prevalence and duration in the proportion of days on VV-ECMO.

Results

Of 47 patients (median age = 51), 6 were in a persistent coma and 40 of the remaining 41 patients (98%) had ICU delirium. Delirium in the survivors (n = 21) and non-survivors (n = 26) was first detected at a similar time point (VV-ECMO day 9.5(5,14) vs. 8.5(5,21), p = 0.56) with similar total delirium days on VV-ECMO (9.5[3.3, 16.8] vs. 9.0[4.3, 28.3] days, p = 0.43). Non-survivors had numerically lower RASS scores on VV-ECMO days (-3.72[-4.42, -2.96] vs. -3.10[-3.91, -2.21], p = 0.06) and significantly prolonged delirium-unassessable days on VV-ECMO with a RASS of -4/-5 (23.0[16.3, 38.3] vs. 17.0(6,23), p = 0.03), and total VV-ECMO days (44.5[20.5, 74.3] vs. 27.0[21, 38], p = 0.04). The proportion of delirium-present days correlated with RASS (r = 0.64, p < 0.001), the proportions of days on VV-ECMO with a neuromuscular blocker (r = -0.59, p = 0.001), and with delirium-unassessable exams (r = -0.69, p < 0.001) but not with overall ECMO duration (r = 0.01, p = 0.96). The average daily dosage of delirium-related medications on ECMO days did not differ significantly. On an exploratory multivariable logistic regression, the proportion of delirium days was not associated with mortality.

Conclusion

Longer duration of delirium was associated with lighter sedation and shorter paralysis, but it did not discern in-hospital mortality. Future studies should evaluate analgosedation and paralytic strategies to optimize delirium, sedation level, and outcomes.

The impact of the COVID-19 pandemic on ICU clinical trials: a description of one research team's experience

BACKGROUND

Disruptions to clinical trials conducted in the intensive care unit (ICU) due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2; coronavirus disease 2019 [COVID-19]) pandemic included fewer new trials activated and more trials stopped. While a number of ongoing, non-COVID-19 clinical trials remained open to enrollment, the direct impact of the pandemic on ICUs instilled chaos in this already challenging environment. The numerous challenges need to be reported so investigators can proactively plan and manage these myriad challenges. Thus, the purpose of this study was to describe the impact of the COVID-19 pandemic on screening and accrual for a non-COVID-19 parent clinical trial enrolling critically ill ICU patients receiving mechanical ventilatory support.

METHODS

A descriptive, retrospective design using quantitative data from detailed screening logs and qualitative observations with field notes from a parent clinical trial were used to address the objectives. The primary aims of the two-site parent clinical trial (n = 190) are to test the efficacy of self-administration of sedative therapy by mechanically ventilated ICU patients on anxiety and delirium occurrence. ICUs from two academic medical centers [names removed for blinding] plus a community hospital in Minnesota were screened daily for alert patients (Richmond Agitation Sedation Scale [RASS] - 2 to + 1), following commands, hemodynamically stable with sufficient hand grip strength to depress a push-button device. Screening data were summarized based on the primary reason patients were not enrolled (screen failures, declinations of consent). Descriptive statistics (frequencies, percentages), chi-square, and Fisher's Exact test were used to describe the data and to determine any differences among distributions of screening failures and recruitment declinations during the defined pre-pandemic (August 27, 2018-March 15, 2020, 2976 screened patients) and pandemic timeframes (March 16, 2020-February 28, 2022, 3912 screened patients). Qualitative data from varied sources such as screening logs, institutional email communications, staff field notes, and research team meeting minutes were summarized into themes.

RESULTS

Despite significantly fewer screen failures due to hypotension, cognitive impairment/dementia, coma, or chemical paralysis with 938 additional patients on the screening log, more were accrued pre-pandemic (n = 55) than during the pandemic period (n = 45); declination reasons were non-significant. Pandemic burdens experienced by study personnel, ICU care providers, and patients/families were revealed that attributed to decreased accrual.

CONCLUSIONS

While the parent clinical trial remained opened, cumulative factors adversely impacted the trial during the pandemic period with fewer patients accrued. The human toll of the pandemic on research staff, clinicians, and patients/family members demands that investigators be proactive in managing these challenges to conduct ICU clinical trials successfully, including careful oversight of human and financial resources.

TRIAL REGISTRATION

ClinicalTrials.gov NCT#02,819,141 Registered 29 June 2016.

Triglyceride Concentrations and Their Relationship to Sedation Choice and Outcomes in Mechanically Ventilated Patients Receiving Propofol

Rationale: Propofol is a first-line sedative agent in the intensive care unit (ICU) but may be associated with hypertriglyceridemia and pancreatitis. To date, the relationship between propofol-induced hypertriglyceridemia and pancreatitis, as well as clinician responses to propofol-induced hypertriglyceridemia, have not been comprehensively studied. Objectives: To assess the incidence of hypertriglyceridemia and pancreatitis in patients receiving continuous propofol infusions in the ICU and to describe the association between hypertriglyceridemia and the use of nonpropofol continuous sedative infusions. Methods: This was a retrospective observational cohort study conducted at three urban academic hospitals within a single health system. Findings were additionally validated using the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database containing data from a separate tertiary care hospital. Mechanically ventilated adult patients who received a continuous propofol infusion between 2016 and 2021 were included. The primary exposure was serum triglyceride concentration, and hypertriglyceridemia was defined as a triglyceride concentration greater than 400 mg/dl. Outcomes included new-onset pancreatitis as well as receipt of midazolam, dexmedetomidine, or ketamine after the triglyceride measurement. The incidence of pancreatitis was compared between groups using a Fisher's Exact test. Multivariable logistic regression was used to assess the association between dichotomized triglyceride concentration and alternative sedative use. Results: In the primary cohort of 7,037 patients, 1,724 (24.5%) had one or more triglyceride concentration measured. Of these, 1,365 (79.2%) had a maximum concentration of less than 400 mg/dl, and 359 (20.8%) had a maximum concentration of greater than 400 mg/dl. Compared with patients with low triglyceride concentrations, patients with high triglyceride concentrations were more likely to receive a continuous infusion of midazolam (37.0% vs. 16.4%; adjusted odds ratio [aOR], 3.1; 95% confidence interval [CI], 2.2-4.4; P < 0.01), ketamine (22.8% vs. 6.9%; aOR, 3.5; 95% CI, 2.3-5.3; P < 0.01), and dexmedetomidine (57.7% vs. 46.6%; aOR, 1.5; 95% CI, 1.1-2.0; P < 0.01). Rates of midazolam infusion increased as triglyceride concentrations exceeded 500 mg/dl. Forty-four (0.6%) patients developed pancreatitis after propofol initiation, of which 4 (9.1%) were considered related to propofol-associated hypertriglyceridemia. Findings were similar in the MIMIC-IV cohort. Conclusions: Propofol-associated hypertriglyceridemia is relatively common in mechanically ventilated ICU patients who have triglycerides measured. Pancreatitis related to propofol-associated hypertriglyceridemia is rare. Patients who develop hypertriglyceridemia while receiving propofol are more likely to receive continuous infusions of other sedatives.

Management of COVID-19 Infection in Pregnancy

Although the majority of pregnant patients who contract severe acute respiratory syndrome coronavirus 2 will have a mild course of illness, pregnant patients with coronavirus disease-2019 are more likely than their nonpregnant counterparts to develop a severe illness with an increased risk of poor maternal and fetal outcomes. Although the extent of research in this specific patient population remains limited, there are tenets of care with which physicians and other providers must be familiar to increase the chances of better outcomes for the two patients in their care.

Prone Positioning Decreases Inhomogeneity and Improves Dorsal Compliance in Invasively Ventilated Spontaneously Breathing COVID-19 Patients—A Study Using Electrical Impedance Tomography

Background: We studied prone positioning effects on lung aeration in spontaneously breathing invasively ventilated patients with coronavirus disease 2019 (COVID-19). Methods: changes in lung aeration were studied prospectively by electrical impedance tomography (EIT) from before to after placing the patient prone, and back to supine. Mixed effect models with a random intercept and only fixed effects were used to evaluate changes in lung aeration. Results: fifteen spontaneously breathing invasively ventilated patients were enrolled, and remained prone for a median of 19 [17 to 21] hours. At 16 h the global inhomogeneity index was lower. At 2 h, there were neither changes in dorsal nor in ventral compliance; after 16 h, only dorsal compliance (βFe +18.9 [95% Confidence interval (CI): 9.1 to 28.8]) and dorsal end-expiratory lung impedance (EELI) were increased (βFe, +252 [95% CI: 13 to 496]); at 2 and 16 h, dorsal silent spaces was unchanged (βFe, –4.6 [95% CI: –12.3 to +3.2]). The observed changes induced by prone positioning disappeared after turning patients back to supine. Conclusions: in this cohort of spontaneously breathing invasively ventilated COVID-19 patients, prone positioning decreased inhomogeneity, increased lung volumes, and improved dorsal compliance.