Comparison of propofol and midazolam for sedation in critically ill patients

Efficacy and Safety of Ciprofol Sedation in ICU Patients Undergoing Mechanical Ventilation: A Multicenter, Single-Blind, Randomized, Noninferiority Trial

OBJECTIVES

To determine the effectiveness and safety of ciprofol for sedating patients in ICUs who required mechanical ventilation (MV).

DESIGN

A multicenter, single-blind, randomized, noninferiority trial.

SETTING

Twenty-one centers across China from December 2020 to June 2021.

PATIENTS

A total of 135 ICU patients 18 to 80 years old with endotracheal intubation and undergoing MV, who were expected to require sedation for 6-24 hours.

INTERVENTIONS

One hundred thirty-five ICU patients were randomly allocated into ciprofol ( n = 90) and propofol ( n = 45) groups in a 2:1 ratio. Ciprofol or propofol were IV infused at loading doses of 0.1 mg/kg or 0.5 mg/kg, respectively, over 4 minutes ± 30 seconds depending on the physical condition of each patient. Ciprofol or propofol were then immediately administered at an initial maintenance dose of 0.3 mg/kg/hr or 1.5 mg/kg/hr, to achieve the target sedation range of Richmond Agitation-Sedation Scale (+1 to -2). Besides, continuous IV remifentanil analgesia was administered (loading dose: 0.5-1 μg/kg, maintenance dose: 0.02-0.15 μg/kg/min).

MEASUREMENTS AND MAIN RESULTS

Of the 135 patients enrolled, 129 completed the study. The primary endpoint-sedation success rates of ciprofol and propofol groups were 97.7% versus 97.8% in the full analysis set (FAS) and were both 100% in per-protocol set (PPS). The noninferiority margin was set as 8% and confirmed with a lower limit of two-sided 95% CI for the inter-group difference of -5.98% and -4.32% in the FAS and PPS groups. Patients who received ciprofol had a longer recovery time ( p = 0.003), but there were no differences in the remaining secondary endpoints (all p > 0.05). The occurrence rates of treatment-emergent adverse events (TEAEs) or drug-related TEAEs were not significantly different between the groups (all p > 0.05).

CONCLUSIONS

Ciprofol was well tolerated, with a noninferior sedation profile to propofol in Chinese ICU patients undergoing MV for a period of 6-24 hours.

Propofol in ICU Settings: Understanding and Managing Anti-Arrhythmic, Pro-Arrhythmic Effects, and Propofol Infusion Syndrome

Propofol has revolutionized anesthesia and intensive care medicine owing to its favorable pharmacokinetic characteristics, fast onset, and short duration of action. This drug has been shown to be remarkably effective in numerous clinical scenarios. In addition, propofol has maintained an overwhelmingly favorable safety profile; however, it has been associated with both antiarrhythmic and proarrhythmic effects. This review concisely summarizes the dual arrhythmic cardiovascular effects of propofol and a rare but serious complication, propofol infusion syndrome (PRIS). We also discuss the need for careful patient evaluation, compliance with recommended infusion rates, and vigilant monitoring.

Sedation strategy and ICU delirium: a multicentre, population-based propensity score-matched cohort study

OBJECTIVES

We examined the relationship between dominant sedation strategy, risk of delirium and patient-centred outcomes in adults admitted to intensive care units (ICUs).

DESIGN

Retrospective propensity-matched cohort study.

SETTING

Mechanically ventilated adults (≥ 18 years) admitted to four Canadian hospital medical/surgical ICUs from 2014 to 2016 in Calgary, Alberta, Canada.

PARTICIPANTS

2837 mechanically ventilated adults (≥ 18 years) requiring admission to a medical/surgical ICU were evaluated for the relationship between sedation strategy and delirium.

INTERVENTIONS

None.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary exposure was dominant sedation strategy, defined as the sedative infusion, including midazolam, propofol or fentanyl, with the longest duration before the first delirium assessment. The primary outcome was 'ever delirium' identified using the Intensive Care Delirium Screening Checklist. Secondary outcomes included mortality, length of stay (LOS), ventilation duration and days with delirium. The cohort was analysed in two propensity score (patient characteristics and therapies received) matched cohorts (propofol vs fentanyl and propofol vs midazolam).

RESULTS

2837 patients (60.7% male; median age 57 years (IQR 43-68)) were considered for propensity matching. In propensity score-matched cohorts(propofol vs midazolam, n=712; propofol vs fentanyl, n=1732), the odds of delirium were significantly higher with midazolam (OR 1.46 (95% CI 1.06 to 2.00)) and fentanyl (OR 1.22 (95% CI 1.00 to 1.48)) compared with propofol dominant sedation strategies. Dominant sedation strategy with midazolam and fentanyl were associated with a longer duration of ventilation compared with propofol. Fentanyl was also associated with increased ICU mortality (OR 1.50, 95% CI 1.07 to 2.12)) ICU and hospital LOS compared with a propofol dominant sedation strategy.

CONCLUSIONS

We identified a novel association between fentanyl dominant sedation strategies and an increased risk of delirium, a composite outcome of delirium or death, duration of mechanical ventilation, ICU LOS and hospital LOS. Midazolam dominant sedation strategies were associated with increased delirium risk and mechanical ventilation duration.

Current status of perioperative hypnotics, role of benzodiazepines, and the case for remimazolam: a narrative review

Anaesthesiologists and non-anaesthesiologist sedationists have a limited set of available i.v. hypnotics, further reduced by the withdrawal of thiopental in the USA and its near disappearance in Europe. Meanwhile, demand for sedation increases and new clinical groups are using what traditionally are anaesthesiologists' drugs. Improved understanding of the determinants of perioperative morbidity and mortality has spotlighted hypotension as a potent cause of patient harm, and practice must be adjusted to respect this. High-dose propofol sedation may be harmful, and a critical reappraisal of drug choices and doses is needed. The development of remimazolam, initially for procedural sedation, allows reconsideration of benzodiazepines as the hypnotic component of a general anaesthetic even if their characterisation as i.v. anaesthetics is questionable. Early data suggest that a combination of remimazolam and remifentanil can induce and maintain anaesthesia. Further work is needed to define use cases for this technique and to determine the impact on patient outcomes.

Nanotherapeutic-directed approaches to analgesia

The ongoing opioid crisis highlighted the need for non-steroidal anti-inflammatory drugs (NSAIDs), nonaddictive analgesics against pain, fever, and inflammation. However, NSAIDs may cause gastrointestinal and cardiovascular adverse effects. To avoid systemic toxicity and deliver drugs to diseased tissues, nanotechnology methods of NSAID encapsulation have been reported and some have reached clinical development. Currently, 57 micro- and nanodrugs are approved by the US FDA. Already approved nanoanalgesics have revealed superior efficacy or reduced toxicity compared with placebo or lower doses of systemically administered active comparators. In this review, the evidence for approval of the marketed nanodrugs will be discussed, with a focus on therapies for pain and inflammation. Nanomedicine remains an attractive field for the development of targeted analgesics.

A systematic review and meta-analysis of propofol versus midazolam sedation in adult intensive care (ICU) patients

PURPOSE

Compare outcomes of adult patients admitted to ICU- length of ICU stay, length of mechanical ventilation (MV), and time until extubation- according to the use of propofol versus midazolam.

METHODS

We searched MEDLINE, EMBASE, LILACS, and Cochrane databases to retrieve RCTs that compared propofol and midazolam used as sedatives in adult ICU patients. We applied a random-effects, meta-analytic model in all calculations. We applied the Cochrane collaboration tool and GRADE. We separated patients into two groups: acute surgical patients (hospitalization up to 24 h) and critically-ill patients (hospitalization over 24 h and whose articles mostly mix surgical, medical and trauma patients).

RESULTS

Globally, propofol was associated with a reduced MV time of 4.46 h (MD: -4.46 [95% CI -7.51 to -1.42] p = 0.004, I2 = 63%, 6 studies) and extubation time of 7.95 h (MD: -7.95 [95% CI -9.86 to -6.03] p < 0.00001, I2 = 98%, 16 studies). Acute surgical patients sedation with propofol compared to midazolam was associated with a reduced ICU stay of 5.07 h (MD: -5.07 [95% CI -8.68 to -1.45] p = 0.006, I2 = 41%, 5 studies), MV time of 4.28 h (MD: -4.28; [95% CI -4.62 to -3.94] p < 0.0001, I2 = 0%, 3 studies), extubation time of 1.92 h (MD: -1.92; [95% CI -2.71 to -1.13] p = 0.00001, I2 = 89%, 9 studies). In critically-ill patients sedation with propofol compared to midazolam was associated with a reduced extubation time of 32.68 h (MD: -32.68 [95% CI -48.37 to -16.98] p = 0.0001, I2 = 97%, 9 studies). GRADE was very low for all outcomes.

CONCLUSIONS

Sedation with propofol compared to midazolam is associated with improved clinical outcomes in ICU, with reduced ICU stay MV time and extubation time in acute surgical patients and reduced extubation time in critically-ill patients.

Guidelines for enhanced recovery after cardiac surgery. Consensus document of Spanish Societies of Anesthesia (SEDAR), Cardiovascular Surgery (SECCE) and Perfusionists (AEP)

The ERAS guidelines are intended to identify, disseminate and promote the implementation of the best, scientific evidence-based actions to decrease variability in clinical practice. The implementation of these practices in the global clinical process will promote better outcomes and the shortening of hospital and critical care unit stays, thereby resulting in a reduction in costs and in greater efficiency. After completing a systematic review at each of the points of the perioperative process in cardiac surgery, recommendations have been developed based on the best scientific evidence currently available with the consensus of the scientific societies involved.

Analgesia and sedation post-coronary artery bypass graft surgery: a review of the literature

This review aimed to study the role of analgesia and sedation after coronary artery bypass graft (CABG) surgery, regarding pain management, assisted respiration, overall postoperative health care, and hospitalization. Data were collected from Pubmed, Scopus, and Cochrane databases. The following terms were used for the search: “analgesia”, “sedation”, “coronary artery bypass grafting”, CABG”, and “opioids”. Articles between the years 1988 and 2018 were evaluated. Several opioid and non-opioid analgesics used to relieve surgical pain are regarded as critical risk factors for developing pulmonary and cardiovascular complications in all kinds of thoracic surgery, especially CABG procedures. Effective pain management in post-CABG patients is largely dependent on effective pain assessment, type of sedatives and analgesics administered, and evaluation of their effects on pain relief. A significant challenge is to determine adequate amounts of administered analgesics and sedatives for postoperative CABG patients, because patients often order more sedatives and analgesics than needed. The pain management process is deemed successful when patients feel comfortable after surgery, with no negative side effects. However, postoperative pain management patterns have not included many modern methods such as patient-controlled analgesia, and postoperative pain management drugs are still limited to a restricted range of opioid and non-opioid analgesics.

Sedative drugs used for mechanically ventilated patients in intensive care units: a systematic review and network meta-analysis

BACKGROUND

The effects of different sedative drugs on all-cause mortality rate, duration of ICU stay, and risk of delirium in mechanically ventilated ICU patients are unclear. This meta-analysis aimed to compare the effectiveness and safety of individual sedative drugs and drug combinations in mechanically ventilated ICU patients.

MATERIALS AND METHODS

Medline, Embase, Cochrane, EBSCOhost, and ISI Web of Science databases were searched for studies that assessed sedation in ICU mechanically ventilated patients. A Bayesian random-effects model was used to combine the direct comparisons and indirect evidence.

RESULTS

Thirty-one randomized, controlled trials were included, which consisted of 4491 patients who received one of seven sedative drugs or a combination of drugs. There were no significant differences regarding the all-cause mortality rate. Compared to propofol, inhalation anesthetics (hazard ratio [HR] 0.121; 95% credible interval [CrI] -7.58 to 7.62), alpha agonists (HR 2.2; 95% CrI 0.776 to 5.22), propofol with benzodiazepines (HR 0.306; 95% CrI -6.97 to 7.65), ketamine with benzodiazepines (HR 6.57; 95% CrI -6.05 to 19.1) and placebo (HR 2.4; 95% CrI -5.37 to 10.3), benzodiazepines (HR 3.62; 95% CrI 0.834 to 6.2) may increase the duration of ICU stay. Compared to alpha agonists, propofol (HR 2.4; 95% CrI 0.304 to 21.1) and placebo (HR 6.12; 95% CrI 0.745 to 54.6), benzodiazepines (HR 2.59; 95% CrI 1.08 to 7.4) were associated with incremental risks of delirium.

CONCLUSION

Compared to propofol, benzodiazepines may increase the duration of ICU stay. Compared to alpha agonists, benzodiazepines were associated with an increased risk of delirium.

Evaluations of Morphine and Fentanyl for Mechanically Ventilated Patients With Respiratory Disorders in Intensive Care: A Systematic Review of Methodological Trends and Reporting Quality

BACKGROUND

Mechanically ventilated patients with respiratory disorders may require sedatives, such as opioids.

OBJECTIVES

To define methodological trends, gaps, and the reporting quality of the comparative clinical and economic evaluations of fentanyl and morphine in ventilated patients in the intensive care unit.

METHODS

We conducted a literature review of the MEDLINE, Embase, OVID, ScienceDirect, Springer Link, and EconLit databases, comparing studies in the management of ventilated patients with respiratory disorders in the intensive care unit using either fentanyl or morphine, or both. We assessed the methodological aspects of the literature characteristics and trends of, for example, modeling, data sources, cost calculation, and data analysis, appraising the quality of reporting via the CONsolidated Standards Of Reporting Trials, STrengthening the Reporting of OBservational studies in Epidemiology, and the Consolidated Health Economic Evaluation Reporting Standards checklists.

RESULTS

Among 1327 articles, 33 (comprising 22 in adults, 8 in neonates, and 3 in pediatrics) met the inclusion criteria. No head-to-head morphine versus fentanyl evaluations explicitly confined to subjects with respiratory conditions were undertaken. Studies relied on various scales to measure the sedation level as a primary study outcome, limiting the comparability of study conclusions. Seven articles of adults were identified to be economic studies from the hospital perspective. On the basis of different endpoints, the same sedation regimen performed differently in various studies. None of the randomized controlled trials, observational cohorts, or pharmacoeconomics studies met most of the assessed reporting quality criteria.

CONCLUSIONS

Our review identified poor reporting quality and high heterogeneity of methods used, potentially limiting the degree to which studies could be interpreted, decisions could be influenced, and findings could be generalized.

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 After Cardiac Surgery: Is One Drug Better Than Another?

The classic high-dose narcotic-based cardiac anesthetic has been modified to facilitate a fast-track, rapid recovery in the intensive care unit (ICU). Postoperative sedation is consequently now an essential component in recovery of the patient undergoing cardiac surgery. It must facilitate the patient's unawareness of the environment as well as reduce the discomfort and anxiety caused by surgery, intubation, mechanical ventilation, suction, and physiotherapy. Benzodiazepines seem well suited for this role, but propofol, opioids, and dexmedetomidine are among other agents commonly used for sedation in the ICU. However, what is an ideal sedative for this application? When compared with benzodiazepine-based sedation regimens, nonbenzodiazepines have been associated with shorter duration of mechanical ventilation and ICU length of stay. Current sedation guidelines recommend avoiding benzodiazepine use in the ICU. However, there are no recommendations on which alternatives should be used. In postcardiac surgery patients, inotropes and vasoactive medications are often required because of the poor cardiac function. This makes sedation after cardiac surgery unique in comparison with the requirements for most other ICU patient populations. We reviewed the current literature to try to determine if 1 sedative regimen might be better than others; in particular, we compare outcomes of propofol and dexmedetomidine in postoperative sedation in the cardiac surgical ICU.

Sedation of mechanically ventilated adults in intensive care unit: a network meta-analysis

Sedatives are commonly used for mechanically ventilated patients in intensive care units (ICU). However, a variety of sedatives are available and their efficacy and safety have been compared in numerous trials with inconsistent results. To resolve uncertainties regarding usefulness of these sedatives, we performed a systematic review and network meta-analysis. Randomized controlled trials comparing sedatives in mechanically ventilated ICU patients were included. Graph-theoretical methods were employed for network meta-analysis. A total of 51 citations comprising 52 RCTs were included in our analysis. Dexmedetomidine showed shorter MV duration than lorazepam (mean difference (MD): 68.7; 95% CI: 18.2-119.3 hours), midazolam (MD: 10.2; 95% CI: 7.7-12.7 hours) and propofol (MD: 3.4; 95% CI: 0.9-5.9 hours). Compared with dexmedetomidine, midazolam was associated with significantly increased risk of delirium (OR: 2.47; 95% CI: 1.17-5.19). Our study shows that dexmedetomidine has potential benefits in reducing duration of MV and lowering the risk of delirium.

Drug-induced HPA axis alterations during acute critical illness: a multivariable association study

OBJECTIVE

Critical illness is hallmarked by low plasma ACTH in the face of high plasma cortisol. We hypothesized that frequently used drugs could play a role by affecting the hypothalamic-pituitary-adrenal axis.

DESIGN

Observational association study.

PATIENTS

A total of 156 medical-surgical critically ill patients.

MEASUREMENTS

Plasma concentrations of ACTH and total/free cortisol were quantified upon ICU admission and throughout the first 3 ICU days. The independent associations between drugs administered 24 h prior to ICU admission and plasma ACTH and cortisol concentrations upon ICU admission were quantified with use of multivariable linear regression analyses.

RESULTS

Upon ICU admission, compared with healthy subjects, patients had low mean±SEM plasma ACTH concentrations (2·7 ± 0·6 pmol/l vs 9·0 ± 1·6 pmol/l, P < 0·0001) in the face of unaltered total plasma cortisol (336·7 ± 30·4 nmol/l vs 300·8 ± 16·6 nmol/l, P = 0·3) and elevated free plasma cortisol concentrations (41·4 ± 5·5 nmol/l vs 5·5 ± 0·8 nmol/l, P = 0·04). Plasma ACTH concentrations remained low (P < 0·001) until day 3, whereas plasma (free) cortisol concentrations steeply increased and remained high (P < 0·001). No independent correlations with plasma ACTH were found. In contrast, the total admission plasma cortisol concentration was independently and negatively associated with the cumulative opioid (P = 0·001) and propofol (P = 0·02) dose, the use of etomidate (P = 0·03), and positively with the cumulative dobutamine dose (P = 0·0007).

CONCLUSIONS

Besides the known suppressive effect of etomidate, opioids and propofol may also suppress and dobutamine increases plasma cortisol in a dose-dependent manner. The observed independent associations suggest drug effects not mediated centrally via ACTH, but rather peripherally by a direct or indirect action on the adrenal cortex.

PRIS may be diagnosed before ICU period for patients undergoing cardiopulmonary bypass

There are many published articles on the clinical manifestations of propofol-related infusion syndrome (PRIS), but they are not the same in each case.(1)Moreover, PRIS is only encountered infrequently and, therefore, it may create a diagnostic challenge. Nearly all of the published articles on PRIS are related to the use of long-term (> 48 hour) propofol infusion with a dose range of at least 4-5 mg/kg/h. In this case, not only a short duration, but also a low-dose propofol administration seems to induce PRIS. A 73-year-old male patient under cardiopulmonary bypass (CPB) suffered from some clinical symptoms of PRIS, such as hyperlactatemia and persistent low metabolic acidosis which promptly resolved on the discontinuation of propofol. Therefore, we suggest that any propofol administration (bolus or infusion) may result in such clinical symptoms, which may be the earliest indicators of PRIS. When those symptoms are observed on propofol administration during cardiopulmonary bypass (CPB), the perfusionist must alert both the anaesthesiologist and the surgeon to stop the propofol in order to prevent the patient from further adverse effects of PRIS.

Sedative efficacy of propofol in patients intubated/ventilated after coronary artery bypass graft surgery

Background:

Sedation after open heart surgery is important in preventing stress on the heart. The unique sedative features of propofol prompted us to evaluate its potential clinical role in the sedation of post-CABG patients.

Objectives:

To compare propofol-based sedation to midazolam-based sedation after coronary artery bypass graft (CABG) surgery in the intensive care unit (ICU).

Patients and Methods:

Fifty patients who were admitted to the ICU after CABG surgery was randomized into two groups to receive sedation with either midazolam or propofol infusions; and additional analgesia was administered if required. Inclusion criteria were as follows: patients 40-60 years old, hemodynamic stability, ejection fraction (EF) more than 40%; exclusion criteria included patients who required intra-aortic balloon pump or inotropic drugs post-bypass. The same protocol of anesthetic medications was used in both groups. Depth of sedation was monitored using the Ramsay sedation score (RSS). Invasive mean arterial pressure (MAP) and heart rate (HR), arterial blood gas (ABG) and ventilatory parameters were monitored continuously after the start of study drug and until the patients were extubated.

Results:

The depth of sedation was almost the same in the two groups (RSS=4.5 in midazolam group vs 4.7 in propofol group; P = 0.259) but the total dose of fentanyl in the midazolam group was significantly more than the propofol group (12.5 mg/hr vs 4 mg/hr) (P = 0.0039). No significant differences were found in MAP (P = 0.51) and HR (P = 0.41) between the groups. The mean extubation time in patients sedated with propofol was shorter than those sedated with midazolam (102 ± 27 min vs 245 ± 42 min, respectively; P < 0.05) but the ICU discharge time was not shorter (47.5 hr vs 36.3 hr, respectively; P = 0.24).

Conclusions:

Propofol provided a safe and acceptable sedation for post-CABG surgical patients, significantly reduced the requirement for analgesics, and allowed for more rapid tracheal extubation than midazolam but did not result in earlier ICU discharge.

The association between sedation practices and duration of mechanical ventilation in intensive care

Choice of sedation agent may influence duration of mechanical ventilation in the intensive care unit (ICU). We conducted a retrospective observational analysis of 2102 consecutive mechanically ventilated ICU patients over an eight-year period at a Melbourne metropolitan hospital with a ten-bed general ICU to determine if propofol was associated with shorter duration of mechanical ventilation (MV) than midazolam. Data were extracted from the hospital administrative database, pharmacy supply order records and ICU database, to calculate rates of MV and tracheostomy, length-of-stay, propofol and midazolam infusion doses, illness severity and casemix and use of 'sedation scores' and 'sedation break' respectively. The primary end-points were duration of MV, tracheostomy rate and hospital outcome. Negative binomial regression and logistic regression were used to identify temporal trends. From 1 July 2002 to 30 June 2010 there were 5751 ICU admissions including 2102 (36.6%) with MV. Over this period there was a 70% decline in annual midazolam use and a greater than fivefold rise in propofol use. 'Sedation scoring' and 'sedation break' procedures were introduced from 2006. Over the eight-year observation period there were significant increases in the numbers of annual MV admissions and long-term (>96 hours) MV patients, but a decline in median duration of MV, tracheostomy rate, median ICU length-of-stay and median hospital length-of-stay. All temporal trends were significant (P <0.05). The temporal association with changes in sedation management practice, including primary sedative agent choice during MV, may explain these findings.

The role of systematic reviews in pharmacovigilance planning and Clinical Trials Authorisation application: example from the SLEEPS trial

BACKGROUND

Adequate sedation is crucial to the management of children requiring assisted ventilation on Paediatric Intensive Care Units (PICU). The evidence-base of randomised controlled trials (RCTs) in this area is small and a trial was planned to compare midazolam and clonidine, two sedatives widely used within PICUs neither of which being licensed for that use. The application to obtain a Clinical Trials Authorisation from the Medicines and Healthcare products Regulatory Agency (MHRA) required a dossier summarising the safety profiles of each drug and the pharmacovigilance plan for the trial needed to be determined by this information. A systematic review was undertaken to identify reports relating to the safety of each drug.

METHODOLOGY/PRINCIPAL FINDINGS

The Summary of Product Characteristics (SmPC) were obtained for each sedative. The MHRA were requested to provide reports relating to the use of each drug as a sedative in children under the age of 16. Medline was searched to identify RCTs, controlled clinical trials, observational studies, case reports and series. 288 abstracts were identified for midazolam and 16 for clonidine with full texts obtained for 80 and 6 articles respectively. Thirty-three studies provided data for midazolam and two for clonidine. The majority of data has come from observational studies and case reports. The MHRA provided details of 10 and 3 reports of suspected adverse drug reactions.

CONCLUSIONS/SIGNIFICANCE

No adverse reactions were identified in addition to those specified within the SmPC for the licensed use of the drugs. Based on this information and the wide spread use of both sedatives in routine practice the pharmacovigilance plan was restricted to adverse reactions. The Clinical Trials Authorisation was granted based on the data presented in the SmPC and the pharmacovigilance plan within the clinical trial protocol restricting collection and reporting to adverse reactions.

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.

Acute lung injury and acute respiratory distress syndrome: experimental and clinical investigations

Acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) can be associated with various disorders. Recent investigation has involved clinical studies in collaboration with clinical investigators and pathologists on the pathogenetic mechanisms of ALI or ARDS caused by various disorders. This literature review includes a brief historical retrospective of ALI/ARDS, the neurogenic pulmonary edema due to head injury, the long-term experimental studies and clinical investigations from our laboratory, the detrimental role of NO, the risk factors, and the possible pathogenetic mechanisms as well as therapeutic regimen for ALI/ARDS.

Acute respiratory distress syndrome and lung injury: Pathogenetic mechanism and therapeutic implication

To review possible mechanisms and therapeutics for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). ALI/ARDS causes high mortality. The risk factors include head injury, intracranial disorders, sepsis, infections and others. Investigations have indicated the detrimental role of nitric oxide (NO) through the inducible NO synthase (iNOS). The possible therapeutic regimen includes extracorporeal membrane oxygenation, prone position, fluid and hemodynamic management and permissive hypercapnic acidosis etc. Other pharmacological treatments are anti-inflammatory and/or antimicrobial agents, inhalation of NO, glucocorticoids, surfactant therapy and agents facilitating lung water resolution and ion transports. β-adrenergic agonists are able to accelerate lung fluid and ion removal and to stimulate surfactant secretion. In conscious rats, regular exercise training alleviates the endotoxin-induced ALI. Propofol and N-acetylcysteine exert protective effect on the ALI induced by endotoxin. Insulin possesses anti-inflammatory effect. Pentobarbital is capable of reducing the endotoxin-induced ALI. In addition, nicotinamide or niacinamide abrogates the ALI caused by ischemia/reperfusion or endotoxemia. This review includes historical retrospective of ALI/ARDS, the neurogenic pulmonary edema due to head injury, the detrimental role of NO, the risk factors, and the possible pathogenetic mechanisms as well as therapeutic regimen for ALI/ARDS.

Pathophysiology of hypopituitarism in the setting of brain injury

The complex pathophysiology of traumatic brain injury (TBI) involves not only the primary mechanical event but also secondary insults such as hypotension, hypoxia, raised intracranial pressure and changes in cerebral blood flow and metabolism. It is increasingly evident that these initial insults as well as transient events and treatments during the early injury phase can impact hypothalamic-pituitary function both acutely and chronically after injury. In turn, untreated pituitary hormonal dysfunction itself can further hinder recovery from brain injury. Secondary adrenal insufficiency, although typically reversible, occurs in up to 50% of intubated TBI victims and is associated with lower systemic blood pressure. Chronic anterior hypopituitarism, although reversible in some patients, persists in 25-40% of moderate and severe TBI survivors and likely contributes to long-term neurobehavioral and quality of life impairment. While the rates and risk factors of acute and chronic pituitary dysfunction have been documented for moderate and severe TBI victims in numerous recent studies, the pathophysiology remains ill-defined. Herein we discuss the hypotheses and available data concerning hypothalamic-pituitary vulnerability in the setting of head injury. Four possible pathophysiological mechanisms are considered: (1) the primary brain injury event, (2) secondary brain insults, (3) the stress of critical illness and (4) medication effects. Although each of these factors appears to be important in determining which hormonal axes are affected, the severity of dysfunction, their time course and possible reversibility, this process remains incompletely understood.

Sedation and analgesia in the mechanically ventilated patient

Sedation and analgesia are important components of care for the mechanically ventilated patient in the intensive care unit (ICU). An understanding of commonly used medications is essential to formulate a sedation plan for individual patients. The specific physiological changes that a critically ill patient undergoes can have direct effects on the pharmacology of drugs, potentially leading to interpatient differences in response. Objective assessments of pain, sedation, and agitation have been validated for use in the ICU for assessment and titration of medications. An evidence-based strategy for administering these drugs can lead to improvements in short- and long-term outcomes for patients. In this article, we review advances in the field of ICU sedation to provide an up-to-date perspective on management of the mechanically ventilated ICU patient.

Cosyntropin as a diagnostic agent in the screening of patients for adrenocortical insufficiency

Adrenocortical insufficiency occurs when there is inadequate release of cortisol from the adrenal cortex. Disturbances of the hypothalamic-pituitary-adrenal axis are common following trauma, surgical stress, and critical illness. While this is often a protective mechanism, these responses may become "uncoupled" or maladaptive resulting in an exacerbation of organ failure and higher mortality rates. In these clinical settings, the patient presents with a persistent systemic inflammation state, a hyperdynamic cardiovascular response, and vasopressor dependent shock. As such, the occurrence of adrenal insufficiency in the setting of critical illness is most appropriately termed critical illness-related corticosteroid insufficiency. In these settings, recent data suggests that these patients may benefit from a short course of low-dose steroid replacement therapy. Cosyntropin, a synthetic derivative of adrenocorticotropic hormone, is being used with increased frequency in the evaluation and diagnosis of adrenocortical insufficiency in this patient population. A random cortisol level is checked before a 250-μg injection of cosyntropin and then 30-60 minutes later. The cortisol levels and response to cosyntropin may be interpreted to identify an insufficient adrenal response. Of note, the setting of critical illness can greatly affect the cosyntropin test sensitivity on identifying adrenal insufficiency. Changes in the stress response during critical illness combined with the resuscitation and management of these patients greatly disturbs serum protein levels, especially those of albumin and transcortin. Common intensive care unit (ICU) diagnoses such as sepsis and malnutrition can increase baseline levels and blunt the cortisol response to cosyntropin stimulation, respectively. As well, numerous pharmacological agents routinely used in the ICU have been shown to interfere with cortisol levels and cosyntropin responsiveness. While steroids have a place in the ICU, specific dosing and length of administration remain inconsistent.

The effect of midazolam on mouse Leydig cell steroidogenesis and apoptosis

The peripheral-type benzodiazepine receptor (PBR), a putative receptor in Leydig cells, modulates steroidogenesis. Since benzodiazepines are commonly used in regional anesthesia, their peripheral effects need to be defined. Therefore, this study set out to investigate in vitro effects of the benzodiazepine midazolam (MDZ) on Leydig cell steroidogenesis, and the possible underlying mechanisms. The effects of MDZ on steroidogenesis in primary mouse Leydig cells and MA-10 Leydig tumor cells were determined by radioimmunoassay. PBR, P450scc, 3beta-HSD and StAR protein expression induced by MDZ was determined by Western blotting. Inhibitors of the signal transduction pathway and a MDZ antagonist were used to investigate the intracellular cascades activated by MDZ. In both cell types, MDZ-stimulated steroidogenesis in dose- and time-dependent manners, and induced the expression of PBR and StAR proteins, but had no effect on P450scc and 3beta-HSD expressions. Moreover, H89 (PKA inhibitor) and GF109203X (PKC inhibitor) attenuated MDZ-stimulated steroid production. Interestingly, the MDZ antagonist (flumazenil) did not decrease MDZ-induced steroid production in both cell types. These results highly indicated that MDZ-induced steroidogenesis in mouse Leydig cells via PKA and PKC pathways, along with the expression of PBR and StAR proteins. In addition, MDZ at high dosages induced rounding-up, membrane blebbing, and then death in MA-10 cells. In conclusion, midazolam could induce Leydig tumor cell steroidogenesis, and high dose of midazolam could induce apoptosis in Leydig tumor cells.

Haemodynamic changes and stress responses of piglets to surgery during total intravenous anaesthesia with propofol and fentanyl

The purpose of the study was to assess the haemodynamic (blood pressure and heart rate) changes and stress responses (serum cortisol and serum amyloid A [SAA] concentrations) to surgery in piglets during total intravenous anaesthesia (TIVA) with propofol and fentanyl. After preanaesthetic medication with intramuscular midazolam (0.5 mg/kg body mass), ketamine (10 mg/kg) and butorphanol (0.5 mg/kg) anaesthesia was induced in five piglets, with intravenous propofol (1 mg/kg) followed by tracheal intubation and mechanical lung ventilation. Soft tissue surgery was performed in the jugular and inguinal regions during TIVA with propofol (8 mg/kg/h) and fentanyl (35 μg/kg/h). Anaesthesia was maintained for 300 min after surgery as the piglets were the control group of a project involving extracorporeal membrane oxygenation. Mean plasma cortisol concentration decreased significantly ( P < 0.05) from 59 ± 39.9 nmol/L (mean ± 1 SD) before surgery to 7.5 ± 2.5 nmol/L 300 min after end of surgical procedure. The mean SAA concentrations increased over the same period from 1.6 ± 2.3 μg/mL to 4.2 ± 5.6 μg/mL without statistical significance. The baseline (presurgery) mean arterial pressure (MAP) was 72 ± 9 mmHg compared with 72 ± 11 mmHg 300 min after end of surgery. Neither heart rate nor lactate concentrations changed significantly over the same time points: heart rate was 104 ± 11 and 103 ± 15 beats/min whereas mean lactate concentrations were reduced from 1.14 ± 0.45 mmol/L to 0.90 ± 0.22 mmol/L. Haemodynamic stability, a decrease in serum cortisol and a non-statistically significant rise in mean SAA concentrations suggest that the anaesthetic described suppresses the stress response of piglets to surgery without adverse cardiovascular effects. Therefore, it may prove useful in cardiovascular research.

Anestesia epidural com lidocaína isolada e associada ao fentanil para realização de ováriossalpingo-histerectomia em cadelas

Investigou-se o efeito da lidocaína isolada ou associada ao fentanil na anestesia epidural, para realização de ováriossalpingo-histerectomia. Dezoito cadelas foram tranqüilizadas com acepromazina, seguindo-se indução anestésica com propofol, para a realização da punção lombossacra. Os animais foram distribuídos em dois grupos: o grupo GL recebeu lidocaína (8,5mg/kg) e o GLF fentanil (5µg/kg) associado à lidocaína (6,5mg/kg). Mensuraram-se as freqüências cardíaca (FC) e respiratória (FR), pressão arterial sistólica (PAS), variáveis hemogasométricas, concentração sérica de cortisol, necessidade de complementação anestésica com propofol durante a cirurgia, temperatura retal (T), período de latência e duração do bloqueio anestésico. Foi observada redução na FC, FR e PAS no GL e GLF, porém esses parâmetros mantiveram-se dentro dos limites fisiológicos. Para ambos os grupos, a concentração sérica de cortisol manteve-se estável após a cirurgia. Complementação anestésica foi necessária em 40% e 75% dos animais do GLF e GL, respectivamente. Conclui-se que ambos os protocolos foram suficientes para inibir a elevação sérica do cortisol, e resultaram em alterações mínimas cardiorrespiratórias, e que a complementação anestésica foi necessária.

[ICU-acquired neuromyopathy, delirium and sedation in intensive care unit]

ICU-acquired neuromyopathy (NMAR) and delirium are the two most frequent and severe neurological complications of intensive care medicine. Their mechanisms still remain to be elucidated. The objective of this review is to address the potential role of sedation in occurrence of these complications. There is no evidence that sedation is involved in NMARs. However, the hypothesis that muscle inactivity induced by sedation fosters NMAR is an argument to discontinue or reduce sedatives infusion whenever possible. It is also recommended not to administer propofol more than 48 h at an infusion rate above 5 mg/kg per hour in patients with systemic inflammatory response syndrome, because of the risk of propofol infusion syndrome, which includes notably rhabdomyolysis. The relationship between delirium and sedation are controversial because in most studies, patients were considered delirious though being still sedated and multivariate analysis was lacking. One study showed that lorazepam given continuously was an independent risk factor for daily transition to delirium 24 h later with a 20% increase risk of every unit dose (expressed as log(e)mg). The impact of deepness, daily interruption or titration of sedation on the prevalence of delirium has never been assessed but it seems that deep sedation has to be avoided.

Protective effects of propofol on acute lung injury induced by oleic acid in conscious rats

OBJECTIVES

Oleic acid has been used to induce acute lung injury (ALI) in animals. In patients with acute respiratory distress syndrome (ARDS), the blood level of oleic acid was increased. The mechanism and therapeutic regimen of ARDS and oleic acid-induced ALI remain undefined. In the present study, we investigated the oleic acid-induced changes in lung variables for the measure of ALI, inflammatory mediators, and neutrophil-derived substances. We evaluated the effects of pretreatment and posttreatment with propofol.

DESIGN

Randomized, controlled animal study.

SETTING

University research laboratory.

SUBJECTS

Fifty adult male Sprague-Dawley rats weighing 250-300 g.

INTERVENTIONS

We employed a conscious and unrestrained rat model. Oleic acid at a dose of 100 mg/kg was administered intravenously. Propofol (30 mg/kg) was given by intravenous infusion (6 mg/kg/min for 5 mins) 30 mins before (pretreatment) and 30 mins after (posttreatment) oleic acid.

MEASUREMENTS AND MAIN RESULTS

We monitored the arterial pressure, heart rate, and blood gas. The lung weight changes, exhaled nitric oxide, protein concentration in bronchoalveolar lavage, and Evans blue content in lung tissue were determined. The plasma nitrate/nitrite, methylguanidine, cytokines (tumor necrosis factor-alpha, interleukin-1beta, interleukin-6, and interleukin-10), neutrophil elastase, myeloperoxidase, malondialdehyde, and sodium- and potassium-activated adenosine triphosphatase (Na+-K+-ATPase) were detected. Histopathological examination of the lung was performed. Oleic acid caused systemic hypotension and severe ALI as evidenced by the increases in the extent of ALI, impairment of pulmonary functions (blood gas variables), and lung pathology. In addition, oleic acid significantly increased inflammatory mediators and neutrophil-derived factors but depressed Na+-K+-ATPase. The inducible nitric oxide synthase was up-regulated. Pre- or posttreatment with propofol was capable of reversing the oleic acid-induced changes and attenuating the extent of ALI.

CONCLUSIONS

Oleic acid resulted in sepsis-like responses including ALI, inflammatory reaction, and increased neutrophil-derived factors. It depressed the Na+-K+-ATPase activity but up-regulated inducible nitric oxide synthase. Treatment with propofol abrogated or reversed the oleic acid-induced changes.

Sedation and analgesia in the intensive care unit

PURPOSE OF REVIEW

Sedation and analgesia are important means of providing care for the critically ill patient.

RECENT FINDINGS

It is now clear that posttraumatic stress disorders resulting from an intensive care unit stay may be prevented by the right level of sedation. New drug developments but also recent findings in new ventilation strategies allow for a sedation management that is better tailored to an individual's need. Most importantly, regular definition of the appropriate level of sedation and analgesia as well as monitoring of the desired level will help to avoid over- and undersedation and may ultimately improve the outcome of the patient and reduce costs.

SUMMARY

Sedation and analgesia are now regarded as an integral part of treatment on the intensive care unit instead of being an unpleasant but necessary and minor issue. The importance of monitoring the level of sedation and analgesia has only recently been realized. It remains to be shown that new management strategies including an evaluation of the patient, planned interventions and the choice of drugs will further improve the care for the critically ill.

Propofol Infusion Syndrome: A Case of Increasing Morbidity With Traumatic Brain Injury

A previously healthy 16-year-old boy with a closed, severe traumatic brain injury was admitted to a surgical and trauma intensive care unit. He was given a continuous infusion of propofol for sedation and to control intracranial pressure. About 3 days after the propofol infusion was started, metabolic acidosis and rhabdomyolysis developed. Acute renal failure ensued as a result of the rhabdomyolysis. Tachycardia with wide QRS complexes developed without hyperkalemia. The patient died of refractory cardiac dysrhythmia and circulatory collapse approximately 36 hours after the first signs of propofol infusion syndrome appeared. Propofol infusion syndrome is a rare but frequently fatal complication in critically ill children who are given prolonged high-dose infusions of the drug. The syndrome is characterized by severe metabolic acidosis, rhabdomyolysis, acute renal failure, refractory myocardial failure, and hyperlipidemia. Despite several publications on the subject in the past decade, most cases still seem to remain undetectable.

A comparison of hypnotic and analgesic based sedation in a general intensive care unit †

BACKGROUND

Sedation of the critically ill patient has several components including hypnosis and analgesia. Hypnotic-based sedation (HBS), where midazolam and/or propofol are used, with morphine or another analgesic added as needed has been common. The advent of remifentanil has allowed greater use of analgesia-based sedation (ABS) where relief of discomfort from the tracheal tube or pain are the important objectives, and hypnosis is given as necessary. Method. We compared HBS and ABS (remifentanil-based sedation) within a general intensive care unit (ICU). During the first study period of 12 weeks, 111 patients received HBS. After the development of new guidelines for the use of remifentanil in the ICU, a second 12 week study period used an analgesia-based regimen, with hypnotics added only if needed.

RESULTS

Ninety-six patients received ABS, and 79 received remifentanil. It was possible to manage 29 (37%) of the patients receiving remifentanil without the use of supplementary hypnotic agents. In the remaining 63% the use of remifentanil was associated with a reduction in the amount and duration of propofol used. Significantly more patients receiving ABS had satisfactory levels of sedation during synchronized intermittent mandatory ventilation (19 [2,55] vs 50 [14,83], P<0.001).

CONCLUSIONS

The use of ABS allowed patients to be managed more comfortably, either without a hypnotic drug or with less hypnotic drug, than using conventional HBS.

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.

A randomized trial of intermittent lorazepam versus propofol with daily interruption in mechanically ventilated patients

OBJECTIVE

To compare duration of mechanical ventilation for patients randomized to receive lorazepam by intermittent bolus administration vs. continuous infusions of propofol using protocols that include scheduled daily interruption of sedation.

DESIGN

A randomized open-label trial enrolling patients from October 2001 to March 2004.

SETTING

Medical intensive care units of two tertiary care medical centers.

PATIENTS

Adult patients expected to require mechanical ventilation for >48 hrs and who required > or =10 mg of lorazepam or a continuous infusion of a sedative to achieve adequate sedation.

INTERVENTIONS

Patients were randomized to receive lorazepam by intermittent bolus administration or propofol by continuous infusion to maintain a Ramsay score of 2-3. Sedation was interrupted on a daily basis for both groups.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was median ventilator days. Secondary outcomes included 28-day ventilator-free survival, intensive care unit and hospital length of stay, and hospital mortality. Median ventilator days were significantly lower in the daily interruption propofol group compared with the intermittent bolus lorazepam group (5.8 vs. 8.4, p = .04). The difference was largest for hospital survivors (4.4 vs. 9.0, p = .006). There was a trend toward greater ventilator-free survival for patients in the daily interruption propofol group (median 18.5 days for propofol vs. 10.2 for lorazepam, p = .06). Hospital mortality was not different.

CONCLUSIONS

For medical patients requiring >48 hrs of mechanical ventilation, sedation with propofol results in significantly fewer ventilator days compared with intermittent lorazepam when sedatives are interrupted daily.

Sedation during mechanical ventilation: A trial of benzodiazepine and opiate in combination*

OBJECTIVE

To compare the efficacy of continuous intravenous sedation with midazolam alone vs. midazolam plus fentanyl ("co-sedation") during mechanical ventilation.

DESIGN

A randomized, prospective, controlled trial.

SETTING

A ten-bed medical intensive care unit at a university hospital.

PATIENTS

Thirty patients with respiratory failure who were expected to require >48 hrs of mechanical ventilation and who were receiving a sedative regimen that did not include opiate pain control.

INTERVENTIONS

An intravenous infusion of either midazolam alone or co-sedation was administered by a nurse-implemented protocol to achieve a target Ramsay Sedation Score set by the patient's physician. Study duration was 3 days, with a brief daily "wake-up."

MEASUREMENTS AND MAIN RESULTS

We recorded the number of hours/day that patients were "off-target" with their Ramsay Sedation Scores, the number of dose titrations per day, the incidence of patient-ventilator asynchrony, and the time required to achieve adequate sedation as measures of sedative efficacy. We also recorded sedative cost in U.S. dollars and adverse events including hypotension, hypoventilation, ileus, and coma. Compared with the midazolam-only group, the co-sedation group had fewer hours per day with an "off-target" Ramsay Score (4.2 +/- 2.4 and 9.1 +/- 4.9, respectively, p < .002). Fewer episodes per day of patient-ventilator asynchrony were noted in the co-sedation group compared with midazolam-only (0.4 +/- 0.1 and 1.0 +/- 0.2, respectively, p < .05). Co-sedation also showed nonsignificant trends toward a shorter time to achieve sedation, a need for fewer dose titrations per day, and a lower total sedative drug cost. There was a trend toward more episodes of ileus with co-sedation compared with midazolam-only (2 vs. 0).

CONCLUSIONS

In mechanically ventilated patients, co-sedation with midazolam and fentanyl by constant infusion provides more reliable sedation and is easier to titrate than midazolam alone, without significant difference in the rate of adverse events.