A method to produce sedation in critically ill patients

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.

Alpha-2 agonists for long-term sedation during mechanical ventilation in critically ill patients

BACKGROUND

Sedation reduces patient levels of anxiety and stress, facilitates the delivery of care and ensures safety. Alpha-2 agonists have a range of effects including sedation, analgesia and antianxiety. They sedate, but allow staff to interact with patients and do not suppress respiration. They are attractive alternatives for long-term sedation during mechanical ventilation in critically ill patients.

OBJECTIVES

To assess the safety and efficacy of alpha-2 agonists for sedation of more than 24 hours, compared with traditional sedatives, in mechanically-ventilated critically ill patients.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 10, 2014), MEDLINE (1946 to 9 October 2014), EMBASE (1980 to 9 October 2014), CINAHL (1982 to 9 October 2014), Latin American and Caribbean Health Sciences Literature (1982 to 9 October 2014), ISI Web of Science (1987 to 9 October 2014), Chinese Biological Medical Database (1978 to 9 October 2014) and China National Knowledge Infrastructure (1979 to 9 October 2014), the World Health Organization international clinical trials registry platform (to 9 October 2014), Current Controlled Trials metaRegister of controlled trials active registers (to 9 October 2014), the ClinicalTrials.gov database (to 9 October 2014), the conference proceedings citation index (to 9 October 2014) and the reference lists of included studies and previously published meta-analyses and systematic reviews for relevant studies. We imposed no language restriction.

SELECTION CRITERIA

We included all randomized and quasi-randomized controlled trials comparing alpha-2 agonists (clonidine or dexmedetomidine) versus alternative sedatives for long-term sedation (more than 24 hours) during mechanical ventilation in critically ill patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and extracted data. We contacted study authors for additional information. We performed meta-analyses when more than three studies were included, and selected a random-effects model due to expected clinical heterogeneity. We calculated the geometric mean difference for continuous outcomes and the risk ratio for dichotomous outcomes. We described the effects by values and 95% confidence intervals (CIs). We considered two-sided P < 0.05 to be statistically significant.

MAIN RESULTS

Seven studies, covering 1624 participants, met the inclusion criteria. All included studies investigated adults and compared dexmedetomidine with traditional sedatives, including propofol, midazolam and lorazepam. Compared with traditional sedatives, dexmedetomidine reduced the geometric mean duration of mechanical ventilation by 22% (95% CI 10% to 33%; four studies, 1120 participants, low quality evidence), and consequently the length of stay in the intensive care unit (ICU) by 14% (95% CI 1% to 24%; five studies, 1223 participants, very low quality evidence). There was no evidence that dexmedetomidine decreased the risk of delirium (RR 0.85; 95% CI 0.63 to 1.14; seven studies, 1624 participants, very low quality evidence) as results were consistent with both no effect and appreciable benefit. Only one study assessed the risk of coma, but lacked methodological reliability (RR 0.69; 95% CI 0.55 to 0.86, very low quality evidence). Of all the adverse events included, the most commonly reported one was bradycardia, and we observed a doubled (111%) increase in the incidence of bradycardia (RR 2.11; 95% CI 1.39 to 3.20; six studies, 1587 participants, very low quality evidence). Our meta-analysis provided no evidence that dexmedetomidine had any impact on mortality (RR 0.99; 95% CI 0.79 to 1.24; six studies, 1584 participants, very low quality evidence). We observed high levels of heterogeneity in risk of delirium (I² = 70%), but due to the limited number of studies we were unable to determine the source of heterogeneity through subgroup analyses or meta-regression. We judged six of the seven studies to be at high risk of bias.

AUTHORS' CONCLUSIONS

In this review, we found no eligible studies for children or for clonidine. Compared with traditional sedatives, long-term sedation using dexmedetomidine in critically ill adults reduced the duration of mechanical ventilation and ICU length of stay. There was no evidence for a beneficial effect on risk of delirium and the heterogeneity was high. The evidence for risk of coma was inadequate. The most common adverse event was bradycardia. No evidence indicated that dexmedetomidine changed mortality. The general quality of evidence ranged from very low to low, due to high risks of bias, serious inconsistency and imprecision, and strongly suspected publication bias. Future studies could pay more attention to children and to using clonidine

Efficacy of sedation regimens to facilitate mechanical ventilation in the pediatric intensive care unit: a systematic review

OBJECTIVE

Children admitted to pediatric intensive care units (PICUs) often receive sedatives to facilitate mechanical ventilation. However, despite their widespread use, data supporting appropriate dosing, safety, and optimal regimens for sedation during mechanical ventilation are lacking. Therefore, we conducted a systematic review of published data regarding efficacy of sedation to facilitate mechanical ventilation in PICU patients. Our primary objective was to identify and evaluate the quality of evidence supporting sedatives used in PICUs for this purpose.

DATA SOURCES

We searched MEDLINE, EMBASE, and The Cochrane Registry of Clinical Trials from 1966 to June 2008 to identify published articles evaluating sedation regimens to facilitate mechanical ventilation in PICU patients.

STUDY SELECTION

We included only those studies of intubated PICU or pediatric cardiac intensive care unit patients receiving pharmacologic agents to facilitate mechanical ventilation that reported quality of sedation as an outcome.

DATA EXTRACTION

We analyzed studies separately for study type and by agents being studied. Studies were appraised using criteria of particular importance for reviews evaluating sedatives.

DATA SYNTHESIS

Our search strategy yielded 39 studies, including 3 randomized trials, 15 cohort studies, and 21 cases series or reports. The 39 studies evaluated a total of 39 different sedation regimens, with 21 different scoring systems, in a total of 901 PICU/cardiac intensive care unit patients ranging in age from 3 days to 19 years old. Most of the studies were small (<30 patients), and only four studies compared one or more agents to another. Few studies thoroughly evaluated drug safety, and only one study met all quality criteria.

CONCLUSIONS

Despite the widespread use of sedatives to facilitate mechanical ventilation in the PICU, we found that high-quality evidence to guide clinical practice is still limited. Pediatric randomized, controlled trials with reproducible methods and assessment of drug safety are needed.

Mechanical ventilation: a tutorial for pharmacists

Mechanical ventilation is an integral part of the critical care environment and requires orchestration by a multidisciplinary team of clinicians to optimize therapeutic outcomes. By tradition, pharmacists have not been included on this team since this therapeutic modality is not considered relevant to their scope of practice. However, pharmacists play a critical role in the management of patients receiving mechanical ventilation by assisting in the development of institutional guidelines and protocols, by maintaining accuracy of prescribed drug dosages, by monitoring for drug-drug and drug-disease interactions, by assisting with alternative drug selections, and by maintaining continued quality assessment of drug administration. Pharmacists able to understand and integrate mechanical ventilation with the pharmacotherapeutic needs of patients are better qualified practitioners. The goal of this article is to help clinical pharmacists better understand the complexities of mechanical ventilation and to apply this information in optimizing delivery of pharmaceutical agents to critical care patients.

Use of a handheld computer by respiratory care practitioners to improve the efficiency of weaning patients from mechanical ventilation

OBJECTIVE

To evaluate the impact of a handheld computer containing a unit-specific weaning protocol on the efficiency of weaning patients from mechanical ventilation.

DESIGN

A prospective before-after study design with consecutive control and intervention time periods.

SETTING

A medical intensive care unit of an urban teaching hospital.

PARTICIPANTS

All patients receiving mechanical ventilation in the medical intensive care unit were eligible for study enrollment.

INTERVENTIONS

Weaning of mechanical ventilation during the control period was conducted by respiratory care practitioners using a previously published protocol (n = 176). During the intervention period, respiratory care practitioners weaned patients using a handheld computer version of the same protocol (n = 176).

MEASUREMENTS AND RESULTS

The time for the first spontaneous breathing trial to occur was significantly shorter during the intervention period compared with the control period (49.9 +/- 63.2 hrs vs. 72.5 +/- 86.9 hrs, p=.018). The percentage of patients undergoing a spontaneous breathing trial when first meeting established criteria for a spontaneous breathing trial was significantly greater during the intervention period (89.8% vs. 63.6%, p<.001). Length of stay in the intensive care unit was also significantly shorter for patients during the intervention period (6.2 +/- 7.1 days vs. 7.7 +/- 8.0 days, p=.018).

CONCLUSIONS

This experience suggests that respiratory care practitioners employing a weaning protocol programmed on a handheld computer can wean patients from mechanical ventilation more efficiently compared with the use of a paper-based weaning protocol.

Confirming the reliability of the sedation-agitation scale administered by ICU nurses without experience in its use

STUDY OBJECTIVES

To determine the validity and reliability of the Sedation-Agitation scale (SAS) when administered by intensive care unit (ICU) nurses with no experience in its use.

DESIGN

Prospective, psychometric evaluation.

SETTING

Adult medical-cardiac ICU.

PATIENTS

Sixty patients.

INTERVENTION

Sedation and agitation were observed simultaneously but independently by nurses and two investigators, and patients were rated with the SAS. The assessment of an experienced clinical nurse specialist was recorded on visual analog scales (VAS) for sedation (VAS-S) and agitation (VAS-A).

MEASUREMENTS AND MAIN RESULTS

The SAS scores of ICU staff nurses were compared with VAS scored by the clinical nurse specialist using Pearson correlation coefficient. The SAS correlated well with VAS-S (Spearman's p = -0.77, p<0.001). Neither SAS nor VAS-A was correlated (Spearman's p = 0.05, p>0.5), but there were few observations of agitated patients. The SAS interrater agreement was excellent between the two trained investigators (weighted K = 0.93, p<0.001) and between investigators and staff nurses (weighted K = 0.85 and 0.87, p<0.001 for both).

CONCLUSION

The SAS is reliable when administered by staff nurses with no experience with it. Due to the paucity of observations of agitated patients, we were unable to determine its validity for assessing agitation.

A prospective evaluation of empiric versus protocol-based sedation and analgesia

STUDY OBJECTIVE

To compare empiric and protocol-based therapies of sedation and analgesia in terms of pharmacologic cost, effects on mechanical ventilation and intensive care unit (ICU) stay, and quality of sedation and analgesia.

DESIGN

Prospective study.

SETTING

A 24-bed medical-surgical-neurologic ICU.

PATIENTS

Seventy-two patients evaluated during empiric therapy and 86 during protocol-based therapy.

INTERVENTION

Assessment of data collected for 4 months before and 5 months after an evidence-based sedation and analgesia protocol was implemented.

MEASUREMENTS AND MAIN RESULTS

Protocol adherence rate was 83.7%. The hourly cost (Canadian dollars) of sedation was less with protocol-based therapy ($5.68 +/- 4.27 vs $7.69 +/- 5.29, p<0.01) likely due to increased lorazepam use. Pharmacologic cost savings may be negated since sedation duration tended to be longer (122.7 +/- 142.8 vs 88.0 +/- 94.8 hrs, p<0.1) and extubation may have been delayed (61.6 +/- 97.4 vs 39.1 +/- 54.7 hrs, p=0.13) with protocol use. Duration of ICU stay after sedation was discontinued was not significantly different before and after protocol implementation. With the protocol, however, the percentage of modified Ramsay sedation scores representing discomfort decreased from 22.4 to 11% (p<0.001) and the percentage at a score of 4 increased from 17.2% to 29.6% (p<0.01). The percentage of modified visual analog measurements representing pain decreased from 9.6 to 5.9% (p<0.05) with the protocol. When data were stratified according to duration of sedation, the benefits and delayed extubation associated with protocol-based therapy were limited to patients requiring long-term sedation.

CONCLUSION

Compliance with this protocol reduced drug costs and enhanced the quality of sedation and analgesia for patients requiring long-term sedation. Protocol-based therapy with lorazepam may have delayed extubation but did not delay ICU discharge.

Effect of a nursing-implemented sedation protocol on the duration of mechanical ventilation

OBJECTIVE

To compare a practice of protocol-directed sedation during mechanical ventilation implemented by nurses with traditional non-protocol-directed sedation administration.

DESIGN

Randomized, controlled clinical trial.

SETTING

Medical intensive care unit (19 beds) in an urban teaching hospital.

PATIENTS

Patients requiring mechanical ventilation (n = 321).

INTERVENTIONS

Patients were randomly assigned to receive either protocol-directed sedation (n = 162) or non-protocol-directed sedation (n = 159).

MEASUREMENTS AND MAIN RESULTS

The median duration of mechanical ventilation was 55.9 hrs (95% confidence interval, 41.0-90.0 hrs) for patients managed with protocol-directed sedation and 117.0 hrs (95% confidence interval, 96.0-155.6 hrs) for patients receiving non-protocol-directed sedation. Kaplan-Meier analysis demonstrated that patients in the protocol-directed sedation group had statistically shorter durations of mechanical ventilation than patients in the non-protocol-directed sedation group (chi-square = 7.00, p = .008, log rank test; chi-square = 8.54, p = .004, Wilcoxon's test; chi-square = 9.18, p = .003, -2 log test). Lengths of stay in the intensive care unit (5.7+/-5.9 days vs. 7.5+/-6.5 days; p = .013) and hospital (14.0+/-17.3 days vs. 19.9+/-24.2 days; p < .001) were also significantly shorter among patients in the protocol-directed sedation group. Among the 132 patients (41.1%) receiving continuous intravenous sedation, those in the protocol-directed sedation group (n = 66) had a significantly shorter duration of continuous intravenous sedation than those in the non-protocol-directed sedation group (n = 66) (3.5+/-4.0 days vs. 5.6+/-6.4 days; p = .003). Patients in the protocol-directed sedation group also had a significantly lower tracheostomy rate compared with patients in the non-protocol-directed sedation group (10 of 162 patients [6.2%] vs. 21 of 159 patients [13.2%], p = .038).

CONCLUSIONS

The use of protocol-directed sedation can reduce the duration of mechanical ventilation, the intensive care unit and hospital lengths of stay, and the need for tracheostomy among critically ill patients with acute respiratory failure.

The use of continuous i.v. sedation is associated with prolongation of mechanical ventilation

STUDY OBJECTIVE

To determine whether the use of continuous i.v. sedation is associated with prolongation of the duration of mechanical ventilation.

DESIGN

Prospective observational cohort study.

SETTING

The medical ICU of Barnes-Jewish Hospital, a university-affiliated urban teaching hospital.

PATIENTS

Two hundred forty-two consecutive ICU patients requiring mechanical ventilation.

INTERVENTIONS

Patient surveillance and data collection.

MEASUREMENTS AND RESULTS

The primary outcome measure was the duration of mechanical ventilation. Secondary outcome measures included ICU and hospital lengths of stay, hospital mortality, and acquired organ system derangements. A total of 93 (38.4%) mechanically ventilated patients received continuous i.v. sedation while 149 (61.6%) patients received either bolus administration of i.v. sedation (n=64) or no i.v. sedation (n=85) following intubation. The duration of mechanical ventilation was significantly longer for patients receiving continuous i.v. sedation compared with patients not receiving continuous i.v. sedation (185+/-190 h vs 55.6+/-75.6 h; p<0.001). Similarly, the lengths of intensive care (13.5+/-33.7 days vs 4.8+/-4.1 days; p<0.001) and hospitalization (21.0+/-25.1 days vs 12.8+/-14.1 days; p<0.001) were statistically longer among patients receiving continuous i.v. sedation. Multiple linear regression analysis, adjusting for age, gender, severity of illness, mortality, indication for mechanical ventilation, use of chemical paralysis, presence of a tracheostomy, and the number of acquired organ system derangements, found the adjusted duration of mechanical ventilation to be significantly longer for patients receiving continuous i.v. sedation compared with patients who did not receive continuous i.v. sedation (148 h [95% confidence interval: 121, 175 h] vs 78.7 h [95% confidence interval: 68.9, 88.6 h]; p<0.001).

CONCLUSION

We conclude from these preliminary observational data that the use of continuous i.v. sedation may be associated with the prolongation of mechanical ventilation. This study suggests that strategies targeted at reducing the use of continuous i.v. sedation could shorten the duration of mechanical ventilation for some patients. Prospective randomized clinical trials, using well-designed sedation guidelines and protocols, are required to determine whether patient-specific outcomes (eg, duration of mechanical ventilation, patient comfort) can be improved compared with conventional sedation practices.