Sedation with dexmedetomidine in the intensive care setting

Recommended dosages of analgesic and sedative drugs in intensive care result in a low incidence of potentially toxic blood concentrations

Background

Standard dosages of analgesic and sedative drugs are given to intensive care patients. The resulting range of blood concentrations and corresponding clinical responses need to be better examined. The purpose of this study was to describe daily dosages, measured blood concentrations, and clinical responses in critically ill patients. The purpose was also to contribute to establishing whole blood concentration reference values of the drugs investigated.

Methods

A descriptive study of prospectively collected data from 302 admissions to a general intensive care unit (ICU) at a university hospital. Ten drugs (clonidine, fentanyl, morphine, dexmedetomidine, ketamine, ketobemidone, midazolam, paracetamol, propofol, and thiopental) were investigated, and daily dosages recorded. Blood samples were collected twice daily, and drug concentrations were measured. Clinical responses were registered using Richmond agitation-sedation scale (RASS) and Numeric rating scale (NRS).

Results

Drug dosages were within recommended dose ranges. Blood concentrations for all 10 drugs showed a wide variation within the cohort, but only 3% were above therapeutic interval where clonidine (57 of 122) and midazolam (38 of 122) dominated. RASS and NRS were not correlated to drug concentrations.

Conclusion

Using recommended dose intervals for analgesic and sedative drugs in the ICU setting combined with regular monitoring of clinical responses such as RASS and NRS leads to 97% of concentrations being below the upper limit in the therapeutic interval. This study contributes to whole blood drug concentration reference values regarding these 10 drugs.

Adverse Hemodynamic Effects of Dexmedetomidine in Critically Ill Elderly Adults

Background: Dexmedetomidine is a currently recommended first-line sedative agent for critically ill patients requiring mechanical ventilation. Recent trials demonstrated no difference in clinical outcomes between patients treated with dexmedetomidine vs usual care, but significantly more hemodynamic adverse effects in the dexmedetomidine group. One subgroup analysis suggested a 90-day mortality benefit in elderly patients, but no distinction was made between groups regarding age when reporting adverse effects. Given potential decreased baroreceptor function in the elderly, adverse hemodynamic effects of dexmedetomidine may impact them more. Objective: To assess the incidence of adverse hemodynamic effects of dexmedetomidine in elderly ICU patients compared to other sedative agents to clarify the role of dexmedetomidine in this patient population. Methods: This was a single-center, retrospective study including mechanically ventilated elderly patients requiring sedative agents for ≥12 hours. The primary outcome evaluated was composite end point of incidence of bradycardia and hypotension. Secondary outcomes included incidence of each adverse event individually, hospital and ICU length of stay, and duration of mechanical ventilation. Results: There was no difference in adverse events between the two groups (58.7% vs 74.1% in the dexmedetomidine vs usual care groups, P =.074). There was no difference in hospital or ICU length of stay. Patients in the dexmedetomidine group were on the ventilator longer than patients in the usual care group with a median of 6 vs 3 days, respectively (P = 0.004). Conclusion: In this single-center, retrospective study dexmedetomidine had a similar incidence of adverse events in elderly patients compare to the usual care group.

Efficacy of high-flow nasal oxygen during drug-induced sleep endoscopy in patients with obstructive sleep apnea

PURPOSE

High-flow nasal oxygenation (HFNO) can provide a low level of continuous positive airway pressure and alveolar recruitment. We aimed to compare the efficacy of pre-oxygenation with HFNO and low-flow nasal oxygenation (LFNO) during drug-induced sleep endoscopy (DISE).

METHODS

In the LFNO group, preoxygenation was performed for 10 min at 3 L·min-1. In the HFNO group, preoxygenation was performed for 10 min at 30 L·min-1 at a fraction of inspired oxygen of 100% using the Optiflow device. From the start of sedative administration to the end of DISE, vital signs were monitored continuously. The primary outcome was the lowest oxygen saturation (SpO2) during DISE.

RESULTS

Of 24 patients enrolled, 12 were randomly assigned to the LFNO and 12 to the HFNO groups. The prevalence of hypoxia events was 75% in the LFNO group and 58% in the HFNO group. The difference in lowest oxygen saturation between the two groups was not significant between the two groups (P=0.665). The lowest SpO2 during all procedures was comparable between the two groups (86.8 ± 6.5% in the LFNO group and 87.2 ± 8.0% in the HFNO group; P=0.912).

CONCLUSIONS

The findings suggest that HFNO may not be superior to LFNO as a preoxygenation tool to prevent hypoxia during DISE.

Dexmedetomidine: A Sedation Alternative in the Intensive Care Setting

In the last 20 years, the occurrences of drug shortages have increased in frequency as well as duration before returning to the mainstream market. This has prompted intensive care unit nurses and medical staff to seek alternate medication infusion options that provide safe yet effective sedation for patients admitted to intensive care units across the country. Dexmedetomidine (PRECEDEX) emerged in 1999 after the Federal Drug Administration approved it for intensive care use but was quickly embraced by anesthesia providers as it rendered patients undergoing procedures or surgery with adequate analgesia and sedation. Dexmedetomidine (PRECEDEX) continued to maintain patients who required short-term intubation and mechanical ventilation with adequate sedation throughout the entire perioperative period. With patients remaining hemodynamically stable in the initial postoperative period, critical care nurses embraced the use of dexmedetomidine (PRECEDEX) in the intensive care unit setting. As dexmedetomidine (PRECEDEX) gained popularity, it has been used to help manage multiple disease processes such as delirium, agitation, alcoholic withdrawal, and anxiety. Dexmedetomidine (PRECEDEX) has been indicated to be a safer alternative to benzodiazepines, narcotics, or propofol (Diprivan), while providing adequate sedation and allowing patients to maintain hemodynamic stability.

Adherence to Sedation Targets With Weight-Based Propofol and Dexmedetomidine in Patients With Morbid Obesity

BACKGROUND

Propofol and dexmedetomidine are routinely used in intensive care units (ICUs). Both are lipophilic, potentially leading to accumulation in adipose tissue. Limited evidence exists on what body weight to utilize in patients with morbid obesity.

OBJECTIVE

The purpose of this research was to evaluate the safety and efficacy of weight-based sedation with propofol and dexmedetomidine in ICU patients with morbid obesity.

METHODS

Retrospective review of ICU patients admitted from January 2018 to January 2020 who were sedated for ≥48 hours was performed. The primary outcome was the percentage of time within target sedation during the first 48 hours, stratified by body mass index (BMI) <40 or ≥40 kg/m². Additional outcomes included adverse events and the infusion rate to achieve target sedation. Data were evaluated using descriptive statistics.

RESULTS

A total of 80 patients were analyzed. Patients on propofol with a BMI <40 kg/m² were in their target Richmond Agitation-Sedation Scale (RASS) 11.7% versus 16.1% with a BMI ≥40 kg/m² (P = .580). Patients with a BMI <40 kg/m² on dexmedetomidine were in their target RASS 27.6% versus 10.7% with a BMI ≥40 kg/m² (P = .053).

CONCLUSION AND RELEVANCE

Body mass index did not significantly alter propofol target sedation attainment. However, patients with morbid obesity on dexmedetomidine demonstrated significantly less time in target sedation. An actual body weight dosing strategy of these drugs did not achieve desired target sedation for those with a BMI ≥40 versus BMI <40 kg/m². These findings support future research on the optimal sedation dosing strategy in this patient population.

Predictors of dexmedetomidine-associated hypotension in critically ill patients

BACKGROUND

Dexmedetomidine is commonly used for sedation in the Intensive Care Unit (ICU), and its use may be associated with hypotension. We sought to determine predictors of dexmedetomidine-associated hypotension.

METHODS

Retrospective, single-center study of 283 ICU patients in four adults ICUs over a 12 month period. Univariate analyses were performed to determine factors associated with dexmedetomidine-related hypotension. Risk factors significant at the 0.20 level in the univariate analysis were considered for inclusion into a step-wise multiple logistical regression model.

RESULTS

Hypotension occurred in 121 (42.8%) patients with a median mean arterial pressure (MAP) nadir of 54 mmHg. Univariate analyses showed an association between hypotension and age (P = 0.03), Acute Physiology and Chronic Health Evaluation II (APACHE II) score (P = 0.02), baseline MAP (<0.001), admission to the cardiothoracic ICU (P = 0.05), history of coronary artery disease (P = 0.02), and postcardiac surgery (P = 0.0009). Admission to the medical ICU was associated with a decrease in development in hypotension (P = 0.03). There was a trend for hypotension with weight (P = 0.09) and history of congestive heart failure (P = 0.12) Only MAP prior to initiation (odds ratio [OR] 0.97, 95% confidence interval [95% CI] 0.95-0.99; P < 0.0001), APACHE II scores (OR 1.06, 95% CI 1.01-1.12; P = 0.017), and history of coronary artery disease (OR 0.48, 95% CI 0.26-0.90, P = 0.022) were independently associated with hypotension by multivariable analysis.

CONCLUSIONS

Dexmedetomidine-associated hypotension is common. Preexisting low blood pressure, history of coronary artery disease, and higher acuity were identified as independent risk factors for dexmedetomidine-associated hypotension.

Predictors of dexmedetomidine-associated hypotension in critically ill patients

Background:

Dexmedetomidine is commonly used for sedation in the Intensive Care Unit (ICU), and its use may be associated with hypotension. We sought to determine predictors of dexmedetomidine-associated hypotension.

Methods:

Retrospective, single-center study of 283 ICU patients in four adults ICUs over a 12 month period. Univariate analyses were performed to determine factors associated with dexmedetomidine-related hypotension. Risk factors significant at the 0.20 level in the univariate analysis were considered for inclusion into a step-wise multiple logistical regression model.

Results:

Hypotension occurred in 121 (42.8%) patients with a median mean arterial pressure (MAP) nadir of 54 mmHg. Univariate analyses showed an association between hypotension and age (P = 0.03), Acute Physiology and Chronic Health Evaluation II (APACHE II) score (P = 0.02), baseline MAP (<0.001), admission to the cardiothoracic ICU (P = 0.05), history of coronary artery disease (P = 0.02), and postcardiac surgery (P = 0.0009). Admission to the medical ICU was associated with a decrease in development in hypotension (P = 0.03). There was a trend for hypotension with weight (P = 0.09) and history of congestive heart failure (P = 0.12) Only MAP prior to initiation (odds ratio [OR] 0.97, 95% confidence interval [95% CI] 0.95–0.99; P < 0.0001), APACHE II scores (OR 1.06, 95% CI 1.01–1.12; P = 0.017), and history of coronary artery disease (OR 0.48, 95% CI 0.26–0.90, P = 0.022) were independently associated with hypotension by multivariable analysis.

Conclusions:

Dexmedetomidine-associated hypotension is common. Preexisting low blood pressure, history of coronary artery disease, and higher acuity were identified as independent risk factors for dexmedetomidine-associated hypotension.