Pharmacoeconomic Modeling of Lorazepam, Midazolam, and Propofol for Continuous Sedation in Critically Ill Patients

Sleep staging in the ICU with heart rate variability and breathing signals. An exploratory cross-sectional study using deep neural networks

Introduction: To measure sleep in the intensive care unit (ICU), full polysomnography is impractical, while activity monitoring and subjective assessments are severely confounded. However, sleep is an intensely networked state, and reflected in numerous signals. Here, we explore the feasibility of estimating conventional sleep indices in the ICU with heart rate variability (HRV) and respiration signals using artificial intelligence methods Methods: We used deep learning models to stage sleep with HRV (through electrocardiogram) and respiratory effort (through a wearable belt) signals in critically ill adult patients admitted to surgical and medical ICUs, and in age and sex-matched sleep laboratory patients Results: We studied 102 adult patients in the ICU across multiple days and nights, and 220 patients in a clinical sleep laboratory. We found that sleep stages predicted by HRV- and breathing-based models showed agreement in 60% of the ICU data and in 81% of the sleep laboratory data. In the ICU, deep NREM (N2 + N3) proportion of total sleep duration was reduced (ICU 39%, sleep laboratory 57%, p < 0.01), REM proportion showed heavy-tailed distribution, and the number of wake transitions per hour of sleep (median 3.6) was comparable to sleep laboratory patients with sleep-disordered breathing (median 3.9). Sleep in the ICU was also fragmented, with 38% of sleep occurring during daytime hours. Finally, patients in the ICU showed faster and less variable breathing patterns compared to sleep laboratory patients Conclusion: The cardiovascular and respiratory networks encode sleep state information, which, together with artificial intelligence methods, can be utilized to measure sleep state in the ICU.

Cardiac Arrest Treatment Center Differences in Sedation and Analgesia Dosing During Targeted Temperature Management

BACKGROUND

Sedation and analgesia are recommended during targeted temperature management (TTM) after cardiac arrest, but there are few data to provide guidance on dosing to bedside clinicians. We evaluated differences in patient-level sedation and analgesia dosing in an international multicenter TTM trial to better characterize current practice and clinically important outcomes.

METHODS

A total 950 patients in the international TTM trial were randomly assigned to a TTM of 33 °C or 36 °C after resuscitation from cardiac arrest in 36 intensive care units. We recorded cumulative doses of sedative and analgesic drugs at 12, 24, and 48 h and normalized to midazolam and fentanyl equivalents. We compared number of medications used, dosing, and titration among centers by using multivariable models, including common severity of illness factors. We also compared dosing with time to awakening, incidence of clinical seizures, and survival.

RESULTS

A total of 614 patients at 18 centers were analyzed. Propofol (70%) and fentanyl (51%) were most frequently used. The average dosages of midazolam and fentanyl equivalents were 0.13 (0.07, 0.22) mg/kg/h and 1.16 (0.49, 1.81) µg/kg/h, respectively. There were significant differences in number of medications (p < 0.001), average dosages (p < 0.001), and titration at all time points between centers (p < 0.001), and the outcomes of patients in these centers were associated with all parameters described in the multivariate analysis, except for a difference in the titration of sedatives between 12 and 24 h (p = 0.40). There were associations between higher dosing at 48 h (p = 0.003, odds ratio [OR] 1.75) and increased titration of analgesics between 24 and 48 h (p = 0.005, OR 4.89) with awakening after 5 days, increased titration of sedatives between 24 and 48 h with awakening after 5 days (p < 0.001, OR > 100), and increased titration of sedatives between 24 and 48 h with a higher incidence of clinical seizures in the multivariate analysis (p = 0.04, OR 240). There were also significant associations between decreased titration of analgesics and survival at 6 months in the multivariate analysis (p = 0.048).

CONCLUSIONS

There is significant variation in choice of drug, dosing, and titration when providing sedation and analgesics between centers. Sedation and analgesia dosing and titration were associated with delayed awakening, incidence of clinical seizures, and survival, but the causal relation of these findings cannot be proven.

Cost-Effectiveness of Midazolam Versus Haloperidol Versus Olanzapine for the Management of Acute Agitation in the Accident and Emergency Department

OBJECTIVES

A multicenter randomized clinical trial in Hong Kong Accident and Emergency (A&E) departments concluded that intramuscular (IM) olanzapine is noninferior to haloperidol and midazolam, in terms of efficacy and safety, for the management of acutely agitated patients in A&E setting. Determining their comparative cost-effectiveness will further provide an economic perspective to inform the choice of sedative in this setting.

METHODS

This analysis used data from a randomized clinical trial conducted in Hong Kong A&E departments between December 2014 and September 2019. A within-trial cost-effectiveness analysis comparing the 3 sedatives was conducted, from the A&E perspective and a within-trial time horizon, using a decision-analytic model. Sensitivity analyses were also undertaken.

RESULTS

In the base-case analysis, median total management costs associated with IM midazolam, haloperidol, and olanzapine were Hong Kong dollar (HKD) 1958.9 (US dollar [USD] 251.1), HKD 2504.5 (USD 321.1), and HKD 2467.6 (USD 316.4), respectively. Agitation management labor cost was the main cost driver, whereas drug costs contributed the least. Midazolam dominated over haloperidol and olanzapine. Probabilistic sensitivity analyses supported that midazolam remains dominant > 95% of the time and revealed no clear difference in the cost-effectiveness of IM olanzapine versus haloperidol (incremental cost-effectiveness ratio 667.16; 95% confidence interval -770.89, 685.90).

CONCLUSIONS

IM midazolam is the dominant cost-effective treatment for the management of acute agitation in the A&E setting. IM olanzapine could be considered as an alternative to IM haloperidol given that there is no clear difference in cost-effectiveness, and their adverse effect profile should be considered when choosing between them.

Prolonged Unconsciousness is Common in COVID-19 and Associated with Hypoxemia

OBJECTIVE

The purpose of this study was to estimate the time to recovery of command-following and associations between hypoxemia with time to recovery of command-following.

METHODS

In this multicenter, retrospective, cohort study during the initial surge of the United States' pandemic (March-July 2020) we estimate the time from intubation to recovery of command-following, using Kaplan Meier cumulative-incidence curves and Cox proportional hazard models. Patients were included if they were admitted to 1 of 3 hospitals because of severe coronavirus disease 2019 (COVID-19), required endotracheal intubation for at least 7 days, and experienced impairment of consciousness (Glasgow Coma Scale motor score <6).

RESULTS

Five hundred seventy-one patients of the 795 patients recovered command-following. The median time to recovery of command-following was 30 days (95% confidence interval [CI] = 27-32 days). Median time to recovery of command-following increased by 16 days for patients with at least one episode of an arterial partial pressure of oxygen (PaO2 ) value ≤55 mmHg (p < 0.001), and 25% recovered ≥10 days after cessation of mechanical ventilation. The time to recovery of command-following  was associated with hypoxemia (PaO2  ≤55 mmHg hazard ratio [HR] = 0.56, 95% CI = 0.46-0.68; PaO2  ≤70 HR = 0.88, 95% CI = 0.85-0.91), and each additional day of hypoxemia decreased the likelihood of recovery, accounting for confounders including sedation. These findings were confirmed among patients without any imagining evidence of structural brain injury (n = 199), and in a non-overlapping second surge cohort (N = 427, October 2020 to April 2021).

INTERPRETATION

Survivors of severe COVID-19 commonly recover consciousness weeks after cessation of mechanical ventilation. Long recovery periods are associated with more severe hypoxemia. This relationship is not explained by sedation or brain injury identified on clinical imaging and should inform decisions about life-sustaining therapies. ANN NEUROL 2022;91:740-755.

Opioid and Benzodiazepine Requirements in Obese Adult Patients Receiving Extracorporeal Membrane Oxygenation

Background: The use of extracorporeal membrane oxygenation (ECMO) sometimes requires deep levels of sedation (Richmond Agitation Sedation Scale [RASS] −5) in patients with acute respiratory distress syndrome (ARDS). The role of obesity in opioid and sedative requirements remains unclear in patients receiving ECMO. Objective: This study sought to determine whether obesity increases midazolam and opioid requirements in patients receiving venovenous (vv)-ECMO up to the first 7 days after initiation. Methods: This was a retrospective cohort study of adult patients with ARDS managed with vv-ECMO. Results: The obese (n = 38) and nonobese (n = 43) groups had similar baseline characteristics. Fentanyl equivalents were significantly higher on day 3 in the obese group ( P = 0.02) despite similar RASS scores with no differences in midazolam requirements. There were no differences in duration of ECMO, length of stay, or mortality. Conclusion and Relevance: Daily midazolam requirements were not significantly different, and opioid requirements were only significantly higher in the obese group on day 3 despite similar levels of sedation. The impact of obesity with the addition of ECMO and how to adapt doses of medications remains elusive.

Serious Cardiovascular Adverse Events Reported with Intravenous Sedatives: A Retrospective Analysis of the MedWatch Adverse Event Reporting System

BACKGROUND

Serious cardiovascular adverse events (SCAEs) associated with intravenous sedatives remain poorly characterized.

OBJECTIVE

The objective of this study was to compare SCAE incidence, types, and mortality between intravenous benzodiazepines (i.e., diazepam, lorazepam, and midazolam), dexmedetomidine, and propofol in the USA over 8 years regardless of the clinical setting where it was administered.

METHODS

The Food and Drug Administration's MedWatch Adverse Event Reporting System was searched between 2004 and 2011 using the Evidex^® platform from Advera Health Analytics, Inc. to identify all reports that included one or more of ten different SCAEs (package insert incidence ≥ 1%) and where an intravenous benzodiazepine, dexmedetomidine, or propofol was the primary suspected drug.

RESULTS

Among the 2326 Food and Drug Administration's MedWatch Adverse Event Reporting System cases reported, 394 (16.9%) were related to a SCAE. The presence of a SCAE (vs. a non-SCAE) is associated with higher mortality (34 vs. 8%, p < 0.001). The percentage of cases with one or more SCAE, the case mortality rate (%), and the incidence of each SCAE (per 10⁶ days of sedative exposure), respectively, were benzodiazepines (14, 26, 13) [diazepam (13, 23, 31); lorazepam (15, 43, 14); midazolam (14, 20, 11)]; dexmedetomidine (40, 15, 13); and propofol (17, 39, 7). Propofol (vs. either a benzodiazepine or dexmedetomidine) was associated with more total SCAEs (268 vs. 126, p < 0.001) but a lower incidence (per 10⁶ days of sedative exposure) of SCAE (7 vs. 13, p = 0.0001) and cardiac arrest [6.3 (benzodiazepine) vs. 6.7 (dexmedetomidine) vs. 1.4 (propofol), p < 0.0001].

CONCLUSIONS

Serious cardiac adverse events account for nearly one-fifth of intravenous sedative Food and Drug Administration's MedWatch Adverse Event Reporting System reports. These SCAEs appear to be associated with greater mortality than non-cardiac serious adverse events. Serious cardiac events may be more prevalent with either benzodiazepines or dexmedetomidine than propofol.

Propofol or benzodiazepines for short- and long-term sedation in intensive care units? An economic evaluation based on meta-analytic results

Purpose

This evaluation compares propofol and benzodiazepine sedation for mechanically ventilated patients in intensive care units (ICUs) in order to identify the potential economic benefits from different payers' perspectives.

Methods

The patient-level simulation model incorporated efficacy estimates from a structured meta-analysis and ICU-related costs from Italy, Germany, France, UK, and the USA. Efficacy outcomes were ICU length of stay (LOS), mechanical ventilation duration, and weaning time. We calculated ICU costs from mechanical ventilation duration and ICU LOS based on national average ICU costs with and without mechanical ventilation. Three scenarios were investigated: 1) long-term sedation >24 hours based on results from randomized controlled trials (RCTs); 2) long-term sedation based on RCT plus non-RCT results; and 3) short-term sedation <24 hours based on RCT results. We tested the model's robustness for input uncertainties by deterministic (DSA) and probabilistic sensitivity analyses (PSA).

Results

In the base case, mean savings with propofol versus benzodiazepines in long-term sedation ranged from €406 (95% confidence interval [CI]: 646 to 164) in Italy to 1,632 € (95% CI: 2,362 to 880) in the USA. Inclusion of non-RCT data corroborated these results. Savings in short-term sedation ranged from €148 (95% CI: 291 to 2) in Italy to €502 (95% CI: 936 to 57) in the USA. Parameters related to ICU and mechanical ventilation had a stronger influence in the DSA than drug-related parameters. In PSA, propofol reduced costs and ICU LOS compared to benzodiazepines in 94%-100% of simulations. The largest savings may be possible in the UK and the USA due to higher ICU costs.

Conclusion

Current ICU sedation guidelines recommend propofol rather than midazolam for mechanically ventilated patients. This evaluation endorses the recommendation as it may lead to better outcomes and savings for health care systems, especially in countries with higher ICU-related costs.

Sedation for critically ill or injured adults in the intensive care unit: a shifting paradigm

As most critically ill or injured patients will require some degree of sedation, the goal of this paper was to comprehensively review the literature associated with use of sedative agents in the intensive care unit (ICU). The first and selected latter portions of this article present a narrative overview of the shifting paradigm in ICU sedation practices, indications for uninterrupted or prolonged ICU sedation, and the pharmacology of sedative agents. In the second portion, we conducted a structured, although not entirely systematic, review of the available evidence associated with use of alternative sedative agents in critically ill or injured adults. Data sources for this review were derived by searching OVID MEDLINE and PubMed from their first available date until May 2012 for relevant randomized controlled trials (RCTs), systematic reviews and/or meta-analyses and economic evaluations. Advances in the technology of mechanical ventilation have permitted clinicians to limit the use of sedation among the critically ill through daily sedative interruptions or other means. These practices have been reported to result in improved mortality, a decreased length of ICU and hospital stay and a lower risk of drug-associated delirium. However, in some cases, prolonged or uninterrupted sedation may still be indicated, such as when patients develop intracranial hypertension following traumatic brain injury. The pharmacokinetics of sedative agents have clinical importance and may be altered by critical illness or injury, co-morbid conditions and/or drug-drug interactions. Although use of validated sedation scales to monitor depth of sedation is likely to reduce adverse events, they have no utility for patients receiving neuromuscular receptor blocking agents. Depth of sedation monitoring devices such as the Bispectral Index (BIS©) also have limitations. Among existing RCTs, no sedative agent has been reported to improve the risk of mortality among the critically ill or injured. Moreover, although propofol may be associated with a shorter time to tracheal extubation and recovery from sedation than midazolam, the risk of hypertriglyceridaemia and hypotension is higher with propofol. Despite dexmedetomidine being linked with a lower risk of drug-associated delirium than alternative sedative agents, this drug increases risk of bradycardia and hypotension. Among adults with severe traumatic brain injury, there are insufficient data to suggest that any single sedative agent decreases the risk of subsequent poor neurological outcomes or mortality. The lack of examination of confounders, including the type of healthcare system in which the investigation was conducted, is a major limitation of existing pharmacoeconomic analyses, which likely limits generalizability of their results.

The pharmacoeconomics of managing acute agitation in the emergency department: what do we know and how do we approach it?

The emergency department (ED) is commonly the first point of care for patients with acute behavioral issues from the community. Routinely, clinical management involves the use of benzodiazepine and/or antipsychotic drugs, when initial de-escalation strategies fail. There is currently scant literature available to inform the clinical management and resource utilization of acute agitation in the ED. This article discusses the approach to pharmacoeconomic studies of acute agitation management in the ED. It explores the conduct of such evaluations and highlights the cost and data sources required. The current difficulties experienced in conducting such evaluations are also discussed. Pharmacoeconomic studies related to the management of acute agitation in ED can be challenging. Robust clinical trials incorporating prospectively designed pharmacoeconomic studies will invariably contribute toward a better understanding of this therapeutic area and optimize the use of scarce resources.

Impact of a national propofol shortage on duration of mechanical ventilation at an academic medical center

OBJECTIVE

To measure the impact of a national propofol shortage on the duration of mechanical ventilation.

DESIGN

Before-after study.

SETTING

Three, noncardiac surgery, adult intensive care units at a 320-bed academic medical center.

PATIENTS

Consecutive patients requiring mechanical ventilation ≥48 hrs, administered a continuously infused sedative ≥24 hrs, extubated, and successfully discharged from the intensive care unit were compared between before (December 1, 2008 to May 31, 2009) and after (December 1, 2009, to May 31, 2010) a propofol shortage.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Sedation drug use and common factors affecting time on mechanical ventilation were collected and if found either to differ significantly (p ≤ .10) between the two groups or to have an unadjusted significant association (p ≤ .10) with time on mechanical ventilation were included in a multivariable model. The unadjusted analyses revealed that the median (interquartile range) duration of mechanical ventilation increased from 6.7 (9.8; n = 153) to 9.6 (9.5; n = 128) days (p = .02). Fewer after-group patients received ≥24 hrs of continuously infused propofol (94% vs. 15%, p < .0001); more received ≥24 hrs of continuously infused lorazepam (7% vs. 15%, p = .037) and midazolam (30% vs. 81%, p < .0001). Compared with the before group, the after group was younger, had a higher admission Acute Physiology and Chronic Health Evaluation II score, was more likely to be admitted by a surgical service, have acute alcohol withdrawal, and be managed with pressure-controlled ventilation as the primary mode of mechanical ventilation. Of these five factors, only the Acute Physiology and Chronic Health Evaluation II score, admission service, and use of a pressure-controlled ventilation affected duration of mechanical ventilation across both groups. Although a regression model revealed that Acute Physiology and Chronic Health Evaluation II score (p < .0001), admission by a medical service (p = .009), and use of pressure-controlled ventilation (p = .02) each affected duration of mechanical ventilation in both groups, inclusion in either the before- or after-propofol shortage groups (i.e., high vs. low use of propofol) did not affect duration of mechanical ventilation (p = .35).

CONCLUSIONS

An 84% decrease in propofol use in the adult intensive care units at our academic institution as a result of a national shortage did not affect duration of mechanical ventilation.

Pharmacology of commonly used analgesics and sedatives in the ICU: benzodiazepines, propofol, and opioids

The ideal sedative or analgesic agent should have a rapid onset of activity, a rapid recovery after drug discontinuation, a predictable dose response, a lack of drug accumulation,and no toxicity. Unfortunately, none of the earlier analgesics, the benzodiazepines,or propofol share all of these characteristics. Patients who are critically ill experience numerous physiologic derangements and commonly require high doses and long durations of analgesic and sedative therapy. There is a paucity of well designed clinical trials evaluating the safety and efficacy of earlier sedative and analgesic agents in the ICU. In addition, the ever-changing dynamics of patients who are critically ill makes the use of sedation a continual challenge during the course of each patient’s admission. To optimize care, clinicians should be familiar with the many pharmacokinetic, pharmacodynamic, and pharmacogenetic variables that can affect the safety and efficacy of sedatives and analgesics.

Pharmacoeconomics of sedation in the ICU

Despite considerable information on the pharmacotherapy of sedation in the ICU, there is little published on the pharmacoeconomics of sedation in patients who are critically ill. The purpose of this article is to discuss the various components that contribute to the cost of treating the agitated ICU patient and to critically review the articles published since 2000 that evaluated costs and cost-effectiveness in ICU patients receiving drugs for agitation and/or pain. Clinicians should look beyond the acquisition cost of a sedative and include the effect of sedatives on the cost of care when selecting the most appropriate sedative.

Efficacy and safety of quetiapine in critically ill patients with delirium: a prospective, multicenter, randomized, double-blind, placebo-controlled pilot study

OBJECTIVE

To compare the efficacy and safety of scheduled quetiapine to placebo for the treatment of delirium in critically ill patients requiring as-needed haloperidol.

DESIGN

Prospective, randomized, double-blind, placebo-controlled study.

SETTING

Three academic medical centers.

PATIENTS

Thirty-six adult intensive care unit patients with delirium (Intensive Care Delirium Screening Checklist score > or = 4), tolerating enteral nutrition, and without a complicating neurologic condition.

INTERVENTIONS

Patients were randomized to receive quetiapine 50 mg every 12 hrs or placebo. Quetiapine was increased every 24 hrs (50 to 100 to 150 to 200 mg every 12 hrs) if more than one dose of haloperidol was given in the previous 24 hrs. Study drug was continued until the intensive care unit team discontinued it because of delirium resolution, therapy > or = 10 days, or intensive care unit discharge.

MEASUREMENTS AND MAIN RESULTS

Baseline characteristics were similar between the quetiapine (n = 18) and placebo (n = 18) groups. Quetiapine was associated with a shorter time to first resolution of delirium [1.0 (interquartile range [IQR], 0.5-3.0) vs. 4.5 days (IQR, 2.0-7.0; p =.001)], a reduced duration of delirium [36 (IQR, 12-87) vs. 120 hrs (IQR, 60-195; p =.006)], and less agitation (Sedation-Agitation Scale score > or = 5) [6 (IQR, 0-38) vs. 36 hrs (IQR, 11-66; p =.02)]. Whereas mortality (11% quetiapine vs. 17%) and intensive care unit length of stay (16 quetiapine vs. 16 days) were similar, subjects treated with quetiapine were more likely to be discharged home or to rehabilitation (89% quetiapine vs. 56%; p =.06). Subjects treated with quetiapine required fewer days of as-needed haloperidol [3 [(IQR, 2-4)] vs. 4 days (IQR, 3-8; p = .05)]. Whereas the incidence of QTc prolongation and extrapyramidal symptoms was similar between groups, more somnolence was observed with quetiapine (22% vs. 11%; p = .66).

CONCLUSIONS

Quetiapine added to as-needed haloperidol results in faster delirium resolution, less agitation, and a greater rate of transfer to home or rehabilitation. Future studies should evaluate the effect of quetiapine on mortality, resource utilization, post-intensive care unit cognition, and dependency after discharge in a broader group of patients.

Pharmacoeconomics of sedation in the ICU

Despite considerable information on the pharmacotherapy of sedation in the ICU, there is little published on the pharmacoeconomics of sedation in patients who are critically ill. The purpose of this article is to discuss the various components that contribute to the cost of treating the agitated ICU patient and to critically review the articles published since 2000 that evaluated costs and cost-effectiveness in ICU patients receiving drugs for agitation and/or pain. Clinicians should look beyond the acquisition cost of a sedative and include the effect of sedatives on the cost of care when selecting the most appropriate sedative.

Economic evaluation of propofol and lorazepam for critically ill patients undergoing mechanical ventilation

OBJECTIVE

The economic implications of sedative choice in the management of patients receiving mechanical ventilation are unclear because of differences in costs and clinical outcomes associated with specific sedatives. Therefore, we aimed to determine the cost-effectiveness of the most commonly used sedatives prescribed for mechanically ventilated critically ill patients.

DESIGN, SETTING, AND PATIENTS

Adopting the perspective of a hospital, we developed a probabilistic decision model to determine whether continuous propofol or intermittent lorazepam was associated with greater value when combined with daily awakenings. We also evaluated the comparative value of continuous midazolam in secondary analyses. We assumed that patients were managed in a medical intensive care unit and expected to require ventilation for > or = 48 hrs. Model inputs were derived from primary analysis of randomized controlled trial data, medical literature, Medicare reimbursement rates, pharmacy databases, and institutional data.

MAIN RESULTS

We measured cost-effectiveness as costs per mechanical ventilator-free day within the first 28 days after intubation. Our base-case probabilistic analysis demonstrated that propofol dominated lorazepam in 91% of simulations and, on average, was both $6,378 less costly per patient and associated with more than three additional mechanical ventilator-free days. The model did not reveal clinically meaningful differences between propofol and midazolam on costs or measures of effectiveness.

CONCLUSION

Propofol has superior value compared with lorazepam when used for sedation among the critically ill who require mechanical ventilation when used in the setting of daily sedative interruption.

Adjunctive Dexmedetomidine Therapy in the Intensive Care Unit: A Retrospective Assessment of Impact on Sedative and Analgesic Requirements, Levels of Sedation and Analgesia, and Ventilatory and Hemodynamic Parameters

STUDY OBJECTIVE

To determine if adjunctive dexmedetomidine therapy in intensive care patients alters requirements for and levels of sedation and analgesia, and to describe hemodynamic and ventilatory parameters.

DESIGN

Retrospective, noncontrolled, descriptive study of clinical practice.

SETTING

Four intensive care units (ICUs; medical, surgical, neurosurgical, or burn) in a university-affiliated medical center.

PATIENTS

Forty patients who were already receiving sustained use of propofol, lorazepam, or fentanyl when dexmedetomidine was started.

MEASUREMENTS AND MAIN RESULTS

Medical records were identified by searching the pharmacy database for patients who had received continuous-infusion dexmedetomidine from January 2000-January 2003 while in one of the four ICUs. Primary end points were discontinuation or dosage reduction of other sedatives or fentanyl from the hour before to 6 hours after starting dexmedetomidine. Other outcomes included levels of sedation and analgesia before and after dexmedetomidine and description of ventilatory and hemodynamic parameters. The initial dexmedetomidine rate of 0.4 +/- 0.25 microg/kg/hour changed minimally through 47.4 +/- 61.1 infusion hours. At 6 hours, 11 of 13 patients receiving propofol, 14 of 23 receiving lorazepam, and 4 of 30 receiving fentanyl had the respective agent discontinued. With dexmedetomidine, the hourly rates and cumulative daily doses were reduced only for propofol. Adequate sedation occurred at rates of 64.6% and 47.9% during the 24-hour periods before and after dexmedetomidine was started, respectively (p=0.001). Four and 12 patients had severe agitation before and after, respectively (p=0.05). One and 12 patients had severe pain before and after, respectively (p=0.02). Nine patients experienced hypotension or bradycardia. Twenty-two patients were successfully extubated within 24 hours of starting dexmedetomidine.

CONCLUSIONS

Adjunctive dexmedetomidine reduces sedative requirements but does not alter analgesic requirements. However, dexmedetomidine was associated with enhanced agitation, severe pain, and hemodynamic compromise. Transitioning to dexmedetomidine from other sedatives and analgesics may not provide optimal sedation and analgesia. Future studies are needed to evaluate dexmedetomidine as a bridge to extubation.

Economic evaluation of sustained sedation/analgesia in the intensive care unit

Lorazepam, midazolam, propofol and opioids are the primary agents that are used for sustained sedation and analgesia of critically ill patients. The choice of agent depends on safety profiles, expected outcomes, cost, patient characteristics and clinical experience. Few studies have comparatively evaluated the sedatives in terms of cost. Many factors, aside from drug costs, influence the total cost of sedation in the intensive care unit. This article reviews the cost parameters of intensive care unit sedation that are specific to the characteristics of commonly used sedatives and analgesics, evaluates economic studies and cost models, summarises alternative methods of sedation and analgesia, and provides practical recommendations for methods of cost containment, including daily sedation interruption, sedation monitoring and protocol implementation.

Withdrawal from lorazepam in critically ill children

BACKGROUND

Sedatives are used in critically ill children to facilitate mechanical ventilation. Although tolerance and withdrawal are associated with use of sedatives, information about withdrawal from benzodiazepines in children is limited.

OBJECTIVE

To document the occurrence of lorazepam withdrawal in critically ill children and identify predictors for the development of withdrawal.

METHODS

This prospective, investigational, open-label study enrolled pediatric patients receiving a continuous infusion of lorazepam for at least 72 hours. The lorazepam dosage was tapered in a uniform fashion over 6 days by decreasing the total daily dose by 50% every other day on 3 occasions; it was then discontinued. The occurrence of withdrawal from lorazepam was determined by pediatric intensive care unit attending physicians based on clinical judgment. Patients were assessed for withdrawal twice daily beginning 48 hours after the initiation of the lorazepam taper. Assessments were continued for 72 hours after lorazepam discontinuation or until the patient experienced withdrawal, whichever came first. Patient demographic, sedative dosing, and lorazepam serum concentration data were collected to identify risk factors for withdrawal.

RESULTS

Twenty-nine patients completed the study. They received lorazepam for a median duration of about 21 days, and withdrawal occurred in 7 patients. There were no significant differences in demographic variables, lorazepam dosage or other sedative therapy, or lorazepam serum concentrations between patients with withdrawal and those without withdrawal. No predictors of withdrawal were identified.

CONCLUSIONS

Withdrawal occurred in 24% of critically ill children receiving long-term sedation from lorazepam. Risk factors for withdrawal are unknown.