Effects From Continuous Infusions of Dexmedetomidine and Propofol on Hemodynamic Stability in Critically Ill Adult Patients With Septic Shock

Niche Roles for Dexmedetomidine in the Intensive Care Unit

OBJECTIVE

Review dexmedetomidine use in critically ill patients for niche indications including sleep, delirium, alcohol withdrawal, sepsis, and immunomodulation.

DATA SOURCES

Literature was sought using PubMed (February 2012-November 2022). Search terms included dexmedetomidine AND (hypnotics OR sedatives OR sleep OR delirium OR immunomodulation OR sepsis OR alcohol withdrawal).

STUDY SELECTION AND DATA EXTRACTION

Relevant studies conducted in humans ≥18 years published in English were included. Exclusion criteria included systematic reviews, meta-analyses, and studies evaluating oral dexmedetomidine or other alpha-2 agonists.

DATA SYNTHESIS

A total of 231 articles were retrieved. After removal of duplicates, title and abstract screening, and application of inclusion criteria, 35 articles were included. Across the clinical conditions included in this review, varying clinical outcomes were seen. Dexmedetomidine may improve morbidity outcomes in delirium, sleep, and alcohol withdrawal syndrome. Due to limited human studies and poor quality of evidence, no conclusions can be drawn regarding the role of dexmedetomidine in immunomodulation or sepsis.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review presents data for potential niche roles of dexmedetomidine aside from sedation in critically ill patients. This may serve as a guide for sedation selection in critically ill patients who may also benefit from the pleiotropic effects of dexmedetomidine due to a clinical condition discussed in this review.

CONCLUSION

While further studies are needed, dexmedetomidine may provide benefit in other indications in critically ill patients including delirium, sleep, and alcohol withdrawal. Given the poor quality of evidence of dexmedetomidine use in immunomodulation and sepsis, no conclusions can be drawn.

Dexmedetomidine for Reduction of Mortality in Septic Shock: a Protocol for a Randomized Controlled Trial (DecatSepsis).. [DOI: 10.21203/rs.3.rs-2891443/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Introduction: Sepsis is a global problem, which has a high mortality in cases of shock. Sepsis and its complications have been linked to acute stress response. Therefore, we hypothesized that decatecholaminization (i.e., reducing adrenergic stress) with dexmedetomidine would reduce mortality and improve the outcomes of septic shock. Methods and Analysis: This is a protocol for an open-label randomized controlled trial that aims to study the impact of heart rate (HR)-calibrated dexmedetomidine infusion on inhospital mortality, which is the study primary outcome, in cases of septic shock. We will use a dose range of 0.2–0.7 mcg/kg/h for 48 hours to keep the HR between 60 and 90 beats per minute (bpm). In ventilated patients, we will use the least conventional sedation that will enable the patients in both groups to tolerate the tube and ventilation. We plan to include 90 patients with sepsis and HR of > 90 bpm while on norepinephrine infusion. The main secondary outcomes are the mean dose of norepinephrine and the mean hemodynamic parameters over the first three days of inclusion or death. We will perform per-protocol and intension-to-treat analyses. The primary outcome will be analyzed using the Chi-square test, and we will report the risk ratio and 95% confidence interval. Thereafter, we will adjust for the confounders (i.e., age, sex, mechanical ventilation, and comorbidities) in a logistic regression. The level of statistical significance will be a p-value ≤ 0.05. Ethics and dissemination: We obtained the institutional review board approval (MS:22.02.1889) on March 19, 2022 at the Mansoura University, Faculty of Medicine. Written informed consent will be obtained from all patients or their relatives. We will publish the study results in a preprint registry and in conferences, with attempt to publish the report in a peer-reviewed journal. Trial registration: Clinical trial registration (https://clinicaltrials.gov/ct2/show/NCT05283083) on March 16, 2022

Effects of dexmedetomidine on hemodynamic, oxygenation, microcirculation, and inflammatory markers in a porcine model of sepsis

PURPOSE

To determine whether dexmedetomidine aggravates hemodynamic, metabolic variables, inflammatory markers, and microcirculation in experimental septic shock.

METHODS

Twenty-four pigs randomized into: Sham group (n = 8), received saline; Shock group (n = 8), received an intravenous infusion of Escherichia coli O55 (3 × 109 cells/mL, 0.75 mL/kg, 1 hour); Dex-Shock group (n = 8), received bacteria and intravenous dexmedetomidine (bolus 0.5 mcg/kg followed by 0.7 mcg/kg/h). Fluid therapy and/ornorepinephrine were administered to maintain a mean arterial pressure > 65 mmHg. Hemodynamic, metabolic, oxygenation, inflammatory markers, and microcirculation were assessed at baseline, at the end of bacterial infusion, and after 60, 120, 180, and 240 minutes.

RESULTS

Compared to Shock group, Dex-Shock group presented a significantly increased oxygen extraction ratio at T180 (23.1 ± 9.7 vs. 32.5 ± 9.2%, P = 0.0220), decreased central venous pressure at T120 (11.6 ± 1 vs. 9.61 ± 1.2 mmHg, P = 0.0214), mixed-venous oxygen saturation at T180 (72.9 ± 9.6 vs. 63.5 ± 9.2%, P = 0.026), and increased plasma lactate (3.7 ± 0.5 vs. 5.5 ± 1 mmol/L, P = 0.003). Despite the Dex-Shock group having a better sublingual vessel density at T240 (12.5 ± 0.4 vs. 14.4 ± 0.3 mL/m2; P = 0.0003), sublingual blood flow was not different from that in the Shock group (2.4 ± 0.2 vs. 2.4 ± 0.1 mL/kg, P = 0.4418).

CONCLUSIONS

Dexmedetomidine did not worsen the hemodynamic, metabolic, inflammatory, or sublingual blood flow disorders resulting from septic shock. Despite inducing a better sublingual vessel density, dexmedetomidine initially and transitorily increased the mismatch between oxygen supply and demand.

Hemodynamic Effects of Ketamine Compared With Propofol or Dexmedetomidine as Continuous ICU Sedation

BACKGROUND

Ketamine has seen increased use for sedation in the intensive care unit. In contrast to propofol or dexmedetomidine, ketamine may provide a positive effect on hemodynamics.

OBJECTIVE

The objective of this study was to compare the development of clinically significant hypotension or bradycardia (ie, negative hemodynamic event) between critically ill adults receiving sedation with ketamine and either propofol or dexmedetomidine.

METHODS

This was a retrospective cohort study of adults admitted to an intensive care unit at an academic medical center between January 2016 and January 2021.

RESULTS

Patients in the ketamine group (n = 78) had significantly less clinically significant hypotension or bradycardia compared with those receiving propofol or dexmedetomidine (n = 156) (34.6% vs 63.5%; P < 0.001). Patients receiving ketamine also experienced smaller degree of hypotension observed by percent decrease in mean arterial pressure (25.3% [17.4] vs 33.8% [14.5]; P < 0.001) and absolute reduction in systolic blood pressure (26.5 [23.8] vs 42.0 [37.8] mm Hg; P < 0.001) and bradycardia (15.5 [24.3] vs 32.0 [23.0] reduction in beats per minute; P < 0.001). In multivariate logistic regression modeling, receipt of propofol or dexmedetomidine was the only independent predictor of a negative hemodynamic event (odds ratio [OR]: 3.3, 95% confidence interval [CI], 1.7 to 6.1; P < 0.001).

CONCLUSION AND RELEVANCE

Ketamine was associated with less clinically relevant hypotension or bradycardia when compared with propofol or dexmedetomidine, in addition to a smaller absolute decrease in hemodynamic parameters. The clinical significance of these findings requires further investigation.

Is the Sympathetic System Detrimental in the Setting of Septic Shock, with Antihypertensive Agents as a Counterintuitive Approach? A Clinical Proposition

Mortality in the setting of septic shock varies between 20% and 100%. Refractory septic shock leads to early circulatory failure and carries the worst prognosis. The pathophysiology is poorly understood despite studies of the microcirculatory defects and the immuno-paralysis. The acute circulatory distress is treated with volume expansion, administration of vasopressors (usually noradrenaline: NA), and inotropes. Ventilation and anti-infectious strategy shall not be discussed here. When circulation is considered, the literature is segregated between interventions directed to the systemic circulation vs. interventions directed to the micro-circulation. Our thesis is that, after stabilization of the acute cardioventilatory distress, the prolonged sympathetic hyperactivity is detrimental in the setting of septic shock. Our hypothesis is that the sympathetic hyperactivity observed in septic shock being normalized towards baseline activity will improve the microcirculation by recoupling the capillaries and the systemic circulation. Therefore, counterintuitively, antihypertensive agents such as beta-blockers or alpha-2 adrenergic agonists (clonidine, dexmedetomidine) are useful. They would reduce the noradrenaline requirements. Adjuncts (vitamins, steroids, NO donors/inhibitors, etc.) proposed to normalize the sepsis-evoked vasodilation are not reviewed. This itemized approach (systemic vs. microcirculation) requires physiological and epidemiological studies to look for reduced mortality.

Incidence and clinical manifestation of iatrogenic opioid withdrawal syndrome in mechanically ventilated patients

OBJECTIVE

The incidence of iatrogenic opioid withdrawal syndrome (IOWS) in mechanically ventilated adults has been questioned in settings driven by analgosedation strategies. This study aimed to describe the incidence, risk factors and clinical impact of IOWS in mechanically ventilated adults.

METHODS

This prospective, observational study was performed between 1 January and 31 August 2018. IOWS was identified based on the presence of at least three signs or symptoms according to the Diagnostic and Statistical Manual 5th edition (DSM-5) criteria after opioid discontinuation or rate reduction. Incidence of IOWS, patient characteristics, opioid administration, and the impact of IOWS on the duration of mechanical ventilator and length of stay in the intensive care unit (ICU) were collected.

RESULTS

Thirteen out of 55 patients (23.6%) manifested withdrawal symptoms. Two patients in the non-withdrawal group also developed hypertensive urgency after opioid discontinuation. Patients who received rapid once-daily weaning, especially rate reduction more than 50 µg as fentanyl equivalent per hour, were associated with IOWS. However, there was no statistically significant difference in ventilator-free days and ICU-free days.

CONCLUSIONS

These findings showed that approximately one-fourth of mechanically ventilated patients who received opioid infusion experienced IOWS. Monitoring for IOWS is recommended especially in patients who received rapid weaning rate of opioids. Future studies to develop IOWS assessment tools with the change of hemodynamic parameters should be performed.

TRIAL REGISTRATION

This trial was registered in ClinicalTrials.gov: identifier NCT03374722, date of registration 15 December 2018.

Hemodynamic Adverse Effects of Dexmedetomidine and Propofol in a Critically Ill Trauma and Surgical Population: A Retrospective Cohort

BACKGROUND

Propofol and dexmedetomidine may cause hemodynamic adverse effects (AEs) and more data are needed in a trauma and surgical population.

OBJECTIVE

The objective of this study was to evaluate the rate of hemodynamic AEs requiring an intervention between dexmedetomidine and propofol in a critically ill trauma and surgical population.

METHODS

This was a retrospective cohort study at a Level 1 trauma center. Intensive care unit patients admitted from October 1, 2017, through October 31, 2018, were divided into two groups: dexmedetomidine or propofol. The primary end point was the proportion of patients who required a therapeutic intervention for a hemodynamic AE within the first 24 hr of initiation of dexmedetomidine or propofol.

RESULTS

A total of 800 charts were reviewed and 85 patients (dexmedetomidine [n = 35] and propofol [n = 50]) were included. The study population consisted of Caucasian (86%) males (61%) with a median age of 61 [interquartile range-IQR 48, 72], and 18% and 24% required antihypertensive and vasopressor agents, respectively. No difference in the primary outcome was observed (17 [49%] vs. 27 [54%], p = .624). There was no difference in the overall incidence of hemodynamic AE (18 [51%] vs. 30 [60%], p = .433). Dexmedetomidine patients had a greater decrease in median heart rate (HR) compared with the propofol (23 [IQR 16, 41] vs. 14 [IQR 5, 24] beats/min, p = .002).

CONCLUSIONS

The rate of hemodynamic AEs requiring therapeutic interventions was similar between dexmedetomidine and propofol in a critically ill trauma and surgical population; however, dexmedetomidine may be associated with a larger decrease in HR.

Predictors of a response to dexmedetomidine in intubated, critically ill adult patients

BACKGROUND

Dexmedetomidine is a centrally acting α-2 receptor agonist used to maintain light analgosedation in mechanically ventilated adults. This study was conducted to determine factors predictive of successful maintenance of light sedation (Richmond Agitation-Sedation Scale (RASS) 0 to -2) for ≥60% of the first 48 h of mechanical ventilation with dexmedetomidine.

METHODS

This was a single-center, retrospective, cohort study of critically ill adult patients receiving dexmedetomidine and admitted to an intensive care unit (ICU) between January 1, 2013, and August 31, 2019. A multivariable logistic regression analysis was performed in patients receiving dexmedetomidine for sedation to assess patient and clinical characteristics associated with a positive clinical response to dexmedetomidine.

RESULTS

Of 1065 patients reviewed for study inclusion, 158 patients were included. Sixty-two percent of patients initiated on dexmedetomidine to maintain light sedation were able to remain within this sedation target ≥60% of the time during the first 48 hours of therapy. Patients maintained within the target RASS score ≥60% of the time had a higher percentage of ventilator-free days at 14 days (p = 0.044). The odds of having a mean time within goal RASS score ≥60% in the first 48 hours of mechanical ventilation after intubation were decreased by 9% for every point increase in sequential organ failure assessment score (odds ratio: 0.91, 95% confidence interval: 0.82-0.99).

CONCLUSION

Patients were less likely to maintain light sedation with dexmedetomidine as their degree of critical illness increased. The duration of time maintained within goal sedation after dexmedetomidine initiation and the impact on patient outcomes remain a research priority.

The effect of dexmedetomidine on vasopressor requirements in patients with septic shock: a subgroup analysis of the Sedation Practice in Intensive Care Evaluation [SPICE III] Trial

BACKGROUND

Septic shock is associated with decreased vasopressor responsiveness. Experimental data suggest that central alpha2-agonists like dexmedetomidine (DEX) increase vasopressor responsiveness and reduce catecholamine requirements in septic shock. However, DEX may also cause hypotension and bradycardia. Thus, it remains unclear whether DEX is hemodynamically safe or helpful in this setting.

METHODS

In this post hoc subgroup analysis of the Sedation Practice in Intensive Care Evaluation (SPICE III) trial, an international randomized trial comparing early sedation with dexmedetomidine to usual care in critically patients receiving mechanical ventilation, we studied patients with septic shock admitted to two tertiary ICUs in Australia and Switzerland. The primary outcome was vasopressor requirements in the first 48 h after randomization, expressed as noradrenaline equivalent dose (NEq [μg/kg/min] = noradrenaline + adrenaline + vasopressin/0.4).

RESULTS

Between November 2013 and February 2018, 417 patients were recruited into the SPICE III trial at both sites. Eighty-three patients with septic shock were included in this subgroup analysis. Of these, 44 (53%) received DEX and 39 (47%) usual care. Vasopressor requirements in the first 48 h were similar between the two groups. Median NEq dose was 0.03 [0.01, 0.07] μg/kg/min in the DEX group and 0.04 [0.01, 0.16] μg/kg/min in the usual care group (p = 0.17). However, patients in the DEX group had a lower NEq/MAP ratio, indicating lower vasopressor requirements to maintain the target MAP. Moreover, on adjusted multivariable analysis, higher dexmedetomidine dose was associated with a lower NEq/MAP ratio.

CONCLUSIONS

In critically ill patients with septic shock, patients in the DEX group received similar vasopressor doses in the first 48 h compared to the usual care group. On multivariable adjusted analysis, dexmedetomidine appeared to be associated with lower vasopressor requirements to maintain the target MAP.

TRIAL REGISTRATION

The SPICE III trial was registered at ClinicalTrials.gov ( NCT01728558 ).

Hemodynamic Effects of Propofol and Dexmedetomidine in Septic Patients Without Shock

Background: Use of nonbenzodiazepine agents propofol and dexmedetomidine are first line for sedation in the intensive care unit (ICU). These agents have been implicated in the development of bradycardia and hypotension in critical illness. Objectives: To compare the development of clinically significant hypotension and/or bradycardia (ie, negative hemodynamic event) in adults with sepsis yet to require vasopressors receiving either propofol or dexmedetomidine for continuous sedation. Methods: This was a retrospective multicenter cohort study of adults with non-vasopressor-dependent sepsis admitted to an ICU at two academic medical centers between July 2013-September 2017. Results: Patients in the propofol (n = 64) and dexmedetomidine (n = 31) groups developed a clinically significant negative hemodynamic event at statistically similar frequencies (34.4% vs 16.1%, P = 0.065). Patients receiving propofol developed a larger degree of hypotension (47.3 vs 34.7 mm Hg reduction, P = 0.031). In multivariable logistic regression modeling, independent predictors of a negative hemodynamic event were a past medical history of chronic kidney disease (odds ratio [OR] = 3.8; 95% CI = 1.17-12.2; P = 0.027) and baseline heart rate (OR = 1.02; 95% CI = 1.00-1.10; P = 0.036). Conclusions and Relevance: A minority of patients with sepsis who received either propofol or dexmedetomidine experienced an event. Patients with sepsis without shock receiving continuous infusions of propofol and dexmedetomidine experienced a negative hemodynamic event at similar frequencies, though the degree of hypotension seen with propofol was greater. The clinical significance of these adverse effects requires cautious use in sepsis and further investigation.

Reconsidering Dexmedetomidine for Sedation in the Critically Ill: Implications of the SPICE III Trial

Dexmedetomidine is a sedative agent that has gained popularity for use in the intensive care unit over the past 20 years. Guidelines recommend dexmedetomidine as a first-line agent to achieve light sedation in mechanically ventilated adults. Recently, the SPICE III (Sedation Practice in Intensive Care Evaluation III) trial was published. This was a randomized controlled trial comparing initial sedation with dexmedetomidine with usual care sedation in adult patients receiving mechanical ventilation. The results of this trial have both validated and contradicted previous findings about dexmedetomidine. This editorial examines the merits of the SPICE III trial and the role of dexmedetomidine in practice following its publication.

Sedation and Analgesia for Mechanically Ventilated Patients in the Emergency Department

Mechanically ventilated patients can experience significant pain and anxiety associated with their care. These symptoms should be aggressively treated, but can be challenging to manage without a systematic approach. This article reviews recent literature, current guidelines, and best practices in managing pain, agitation, and anxiety in mechanically ventilated patients in the emergency department.

Pharmacologic Considerations Surrounding Sedation, Delirium, and Sleep in Critically Ill Adults: A Narrative Review

INTRODUCTION

Agitation, delirium, and sleep dysfunction in the intensive care unit (ICU) are common occurrences that result in negative patient outcomes. With the recent publication of the 2018 Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU (PAD-IS), several areas are of particular interest due to emerging literature or conflicting results of research.

OBJECTIVE

To highlight areas where emerging literature or variable study results exist and to provide the clinician with recommendations regarding patient management.

METHODS

The 2018 PAD-IS guidelines were reviewed, and areas of emerging literature or lack of consensus of included investigations surrounding pharmacologic management of sedation, delirium, and sleep in the ICU were identified. A review and appraisal of the literature was conducted specifically to address the identified areas. Prospective, randomized trials were included in this narrative review.

RESULTS

Four areas with emerging data or conflicting evidence were identified and included: use of propofol or dexmedetomidine for sedation, pharmacologic prevention of delirium, treatment of delirium, and pharmacologic strategies to improve sleep.

CONCLUSION

A comprehensive approach to the prevention and management of delirium, sedation, and sleep in the ICU is necessary to optimize patient outcomes.