Sedation assessment in critically ill adults

A summary of the current diagnostic methods for, and exploration of the value of microRNAs as biomarkers in, sepsis-associated encephalopathy

Sepsis-associated encephalopathy (SAE) is an acute neurological deficit caused by severe sepsis without signs of direct brain infection, characterized by the systemic inflammation and disturbance of the blood-brain barrier. SAE is associated with a poor prognosis and high mortality in patients with sepsis. Survivors may exhibit long-term or permanent sequelae, including behavioral changes, cognitive impairment, and decreased quality of life. Early detection of SAE can help ameliorate long-term sequelae and reduce mortality. Half of the patients with sepsis suffer from SAE in the intensive care unit, but its physiopathological mechanism remains unknown. Therefore, the diagnosis of SAE remains a challenge. The current clinical diagnosis of SAE is a diagnosis of exclusion; this makes the process complex and time-consuming and delays early intervention by clinicians. Furthermore, the scoring scales and laboratory indicators involved have many problems, including insufficient specificity or sensitivity. Thus, a new biomarker with excellent sensitivity and specificity is urgently needed to guide the diagnosis of SAE. MicroRNAs have attracted attention as putative diagnostic and therapeutic targets for neurodegenerative diseases. They exist in various body fluids and are highly stable. Based on the outstanding performance of microRNAs as biomarkers for other neurodegenerative diseases, it is reasonable to infer that microRNAs will be excellent biomarkers for SAE. This review explores the current diagnostic methods for sepsis-associated encephalopathy (SAE). We also explore the role that microRNAs could play in SAE diagnosis and if they can be used to make the SAE diagnosis faster and more specific. We believe that our review makes a significant contribution to the literature because it summarizes some of the important diagnostic methods for SAE, highlighting their advantages and disadvantages in clinical use, and could benefit the field as it highlights the potential of miRNAs as SAE diagnostic markers.

Ramsay Sedation Scale and Richmond Agitation Sedation Scale: A Cross-sectional Study

BACKGROUND

Many sedation scales and tools have been developed and compared for validity in critically ill patients. However, selection and use of sedation scales vary among intensive care units.

OBJECTIVE

The aim of this study is to compare the reliability of 2 sedation scales-Ramsay Sedation Scale and Richmond Agitation-Sedation Scale (RASS)-in the adult intensive care unit.

METHOD

Four hundred twenty-five patients were recruited in the study. Informed consent had been obtained from each patient guardian/relative. However, only 290 patients (68.24%) completed the study and were independently assessed for sedation effect by investigator and bedside nurses simultaneously using Ramsay scale and RASS.

RESULTS

Agreement between the nurse and investigator scores on Ramsay scale (weighted κ = 0.449, P < .001) indicated weak level of agreement. Agreement between the nurse and investigator on RASS (weighted κ = 0.879, P < .001) indicated a strong level of agreement. Cronbach α analysis showed that 10 items of RASS had an excellent level of internal consistency (α = .989) compared with good level of internal consistency of Ramsay scale (α = .828).

DISCUSSION

Richmond Agitation-Sedation Scale showed excellent interrater agreement compared with weak interrater agreement of Ramsay scale. The results also support that RASS has consistent agreement with clinical observation and practice among different observers. The results suggest that use of RASS is linked to a more reliable assessment of sedation levels in the intensive care unit.

The Impact of Bispectral Index Monitoring on Sedation Administration in Mechanically Ventilated Patients

The aim of this prospective randomised controlled trial was to assess the effectiveness of the Bispectral Index (BIS) monitor in supporting clinical sedation management decisions in mechanically ventilated intensive care unit patients. Fifty adult mechanically ventilated surgical and general intensive care unit patients receiving sedative infusions of morphine and midazolam were randomly allocated to receive BIS monitoring (n=25) or standard sedation management (n=25). In the BIS group, sedation was titrated to maintain a BIS value of greater than 70. In the standard management group, sedative needs were titrated based on subjective assessment and clinical signs.

There was no statistically significant difference in the amount of sedation administered (morphine P =0.67 and midazolam P =0.85). However, there was a statistically significant difference in sedation administration over time. Patients in the BIS group received increasing amounts of sedation over time whilst those in the control group received decreasing amounts of sedation over time. The same inverse relationship existed for both sedative agents (morphine P=0.005, midazolam P=0.03). Duration of mechanical ventilation was comparable in the two groups. We conclude that the use of BIS monitoring did not reduce the amount of sedation used, the length of mechanical ventilation time or the length of ICU stay.

The Effect of Daily Sedation-Weaning Application on Morbidity and Mortality in Intensive Care Unit Patients

Background/aims

Sedation is one of the most important components of intensive care unit (ICU) in patients who are mechanically ventilated at intensive care conditions. As a result of sedation and analgesia in the intensive care unit, the patient is to be awakened a comfortable and easy process. The aim of the study is to demonstrate the effects of day-time sedation interruptions in intensive care patients.

Material and methods

We made a retrospective review of 100 patients who were monitored, mechanically ventilated and treated at our intensive care unit between January 2008 and January 2013. Patients were divided into two groups, including Group P (continuous infusion of sedative agent) and Group D (daily sedation interruptions - daily recovery).

Demographics, mechanical ventilation time, stay at intensive care unit, hospitalization period, time of first weaning, success of weaning, ventilator-related pneumonia (VRP), total doses of drugs, re-intubation frequency, Acute Physiology and Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA) scores and mortality rates of patients were compared. Ramsay Sedation Score (RSS) was used to evaluate the level of sedation. Considering that ideal sedation level is "3" with RSS, RSS < 3 is considered as mild sedation, while RSS > 3 is considered as deep sedation.

Results

There was no difference between demographics of patients. Mechanical ventilation period was significantly longer in Group P than Group D (p < 0.001). When stay at ICU unit was considered, ICU stay was significantly longer in Group P than Group D (p < 0.001). No statistically significant difference was found between two groups with respect to hospitalization period. In inter-group comparison, time to start first weaning was significantly late in Group P than Group D (p < 0.05). There was no difference between groups in terms of frequency of success of weaning and mortality rate (p > 0.05). In inter-group comparison the frequency of reintubation viewed in Group D was significantly less than in Group P (p < 0.05). Considering development of VRP, it was significantly more common in Group P in comparison with Group D (p < 0.05). No statistically significant difference was found between groups in terms of doses of sedative agents (p > 0.05). Considering doses of opioid analgesics, the total dose of fentanyl was significantly higher in Group P than Group D (p = 0.04), while no difference was found for doses of morphine (p > 0.05). Again, no statistical difference was found in doses of muscle relaxant agents (p > 0.05).

Conclusion

It was observed that the sedation technique with daily interruption is superior to continuous infusion of sedatives. Accordingly, we believe that daily weaning will make positive contributions to patients who are mechanically ventilated at intensive care unit.

Experienced Use of Dexmedetomidine in the Intensive Care Unit: A Report of a Structured Consensus

Objective

Management of pain, agitation and delirium (PAD) remains to be a true challenge in critically ill patients. The pharmacological proprieties of dexmedetomidine (DEX) make it an ideal candidate drug for light and cooperative sedation, but many practical questions remain unanswered. This structured consensus from 17 intensivists well experienced on PAD management and DEX use provides indications for the appropriate use of DEX in clinical practice.

Methods

A modified RAND/UCLA appropriateness method was used. In four predefined patient populations, the clinical scenarios do not properly cope by the current recommended pharmacological strategies (except DEX), and the possible advantages of DEX use were identified and voted for agreement, after reviewing literature data.

Results

Three scenarios in medical patients, five scenarios in patients with acute respiratory failure undergoing non-invasive ventilation, three scenarios in patients with cardiac surgery in the early postoperative period and three scenarios in patients with overt delirium were identified as challenging with the current PAD strategies. In these scenarios, the use of DEX was voted as potentially useful by most of the panellists owing to its specific pharmacological characteristics, such as conservation of cognitive function, lack of effects on the respiratory drive, low induction of delirium and analgesia effects.

Conclusion

DEX might be considered as a first-line sedative in different scenarios even though conclusive data on its benefits are still lacking.

Meeting the challenge: ICU-nurses' experiences of lightly sedated patients

BACKGROUND

Sedation of intensive care patients is necessary for comfort and to implement appropriate treatment. The trend of sedation has gone from deep to light sedation. The topic is of interest to intensive care nursing because patients are generally more awake, which requires a different clinical approach than caring for deeply sedated patients.

PURPOSE

The aim of this study was to describe intensive care unit (ICU) nurses experiences of caring for patients who are lightly sedated during mechanical ventilation.

METHODS

A qualitative approach was used. Semi-structured interviews with nine intensive care nurses were conducted. The interview texts were subjected to qualitative content analysis, resulting in the formulation of one main category and six sub-categories.

FINDINGS

The nurses' experience of lightly sedated patients was described as a challenge requiring knowledge and experience. The ability to communicate with the lightly sedated patient is perceived as important for ICU nurses. Individualised nursing care respecting the patients' integrity, involvement and participation are goals in intensive care, but might be easier to achieve when the patients are lightly sedated.

CONCLUSION

The results reinforce the importance of communication in nursing care. It is difficult however to create an inter-personal relationship, encourage patient involvement, and maintain communication with deeply sedated patients. When patients are lightly sedated, the nurses are able to communicate, establish a relationship and provide individualised care. This is a challenge requiring expertise and patience from the nurses. Accomplishing this increases the nurses satisfaction with their care. The positive outcome for the patients is that their experience of their stay in the ICU might become less traumatic.

The use of observational scales to monitor symptom control and depth of sedation in patients requiring palliative sedation: a systematic review

BACKGROUND

Palliative sedation is the intentional lowering of consciousness of a patient in the last phase of life to relieve suffering from refractory symptoms such as pain, delirium and dyspnoea.

AIM

In this systematic review, we evaluated the use of monitoring scales to assess the degree of control of refractory symptoms and/or the depth of the sedation.

DESIGN

A database search of PubMed and Embase was performed up to January 2010 using the search terms 'palliative sedation' OR 'terminal sedation'.

DATA SOURCES

Retro- and prospective studies as well as reviews and guidelines containing information about monitoring of palliative sedation, written in the English, German or Dutch language were included.

RESULTS

The search yielded 264 articles of which 30 were considered relevant. Most studies focused on monitoring refractory symptoms (pain, fatigue or delirium) or the level of awareness to control the level of sedation. Four prospective and one retrospective study used scales validated in other settings: the Numeric Pain Rating Scale, the Visual Analogue Scale, the Memorial Delirium Assessment Scale, the Communication Capacity Scale and Agitation Distress Scale. Only the Community Capacity Scale was partially validated for use in a palliative sedation setting. One guideline described the use of a scale validated in another setting.

CONCLUSIONS

A minority of studies reported the use of observational scales to monitor the effect of palliative sedation. Future studies should be focused on establishing proper instruments, most adequate frequency and timing of assessment, and interdisciplinary evaluation of sedation depth and symptom control for palliative sedation.

Implementation of a guideline for the treatment of pain, sedation, agitation and neuromuscular blockade in the mechanically ventilated adult patient in the emergency department

Purpose:

When emergency department (ED) overcrowding includes admitted mechanically ventilated (MV) critically-ill patients without an open intensive care unit (ICU) bed, emergency providers must deliver ICU level care in the ED. Implementing standardized hospital based clinical guidelines may help providers achieve uniform care standards for assessing and managing pain and sedation for the MV patient.

Objective:

This paper is a description of a hospital performance improvement project that was implemented in the ED. The objective of this study was to measure the degree of adoption of a hospital-wide clinical guideline for the management of pain, sedation and neuromuscular blockade in MV patients into clinical practice in the ED.

Methods:

A retrospective analysis was performed for all mechanically ventilated patients who were admitted from ED to an Intensive Care Unit (ICU). Patient charts were reviewed before (December 2005) and after the implementation of the guideline (June, August, and December 2006). Data was collected and analyzed for the ED visit only and no ICU data was used. The primary outcome was the degree of adoption of the guideline by emergency providers into their daily clinical practice.

Results:

A convenience sample of 170 adult MV patients who were admitted to the ICU during the preselected time period was analyzed. There were no demographic differences between groups of patients observed during each month interval, age (P = 0.34), gender (P = 0.40), race (P = 0.14), and Hispanic ethnicity (P = 0.84). Overall, there was an increase in the provider use of propofol (P < 0.01), RASS sedation scale (P < 0.01), and a decrease in the use of a paralytic agent (P < 0.01).

Conclusion:

There was partial adoption of a guideline into their clinical practice by emergency providers in a busy urban emergency department. Across the 12-month implementation period, there was improvement in the assessment of and use of analgesia and sedation for MV patients.

Sedation Guidelines for Gastro Intestinal Endoscopy

Effective sedation is usually a vital precursor to any successful endoscopic procedure. With advanced techniques and medications available today this component of the procedure can be dealt with safely and in an efficient manner.

Clinical survey of sedation and analgesia procedures in intensive care units

BACKGROUND

The proper use of sedation and analgesia in the intensive care unit (ICU) minimizes its physical and psychological impact. Otherwise, patients can suffer from recall, nightmares, and depression after discharge. We investigated the sedatives, analgesics, and muscle relaxants used in the ICU.

METHODS

We visited 79 ICUs in 52 training hospitals and noted the use of sedatives, analgesics, and muscle relaxants from July, 2007, to December, 2007, using a 5-item questionnaire with 57 sub-questions. The survey evaluated the ICU system administration of analgesics and muscle relaxants.

RESULTS

Most ICU management is done by the anesthesiology department (55%). Most have resident doctors (63.3%) and an ICU committee (60.8%) in charge of the ICU, as well as a special ICU chart (88.6%) and scoring system (65.8%). Most hospitals have a consulting system (94.9%). The standard ICU analgesics are fentanyl (65.8%), NSAIDs (53.2%), and morphine (48.1%).

CONCLUSIONS

Adequate sedation is difficult to achieve in the ICU, but is important for patient comfort and to reduce ICU stay duration. Awareness of patient status and appropriate drug/protocol use are therefore important.

Age-dependent relationship between bispectral index and sedation level

STUDY OBJECTIVE

To determine the relationship between bispectral index (BIS) and sedation.

DESIGN

Prospective, observational clinical study.

SETTING

Intensive care unit of a public hospital in Japan.

PATIENTS

22 ASA physical status I, II, and III middle-aged (18-65 yrs) and elderly (>65 yrs) patients receiving postoperative sedation with midazolam.

INTERVENTIONS

Patients were allocated to two groups: Group M was composed of middle-aged patients (<65 yrs) and Group H elderly patients (>65 yrs). Midazolam was administered at a bolus dose of 0.1 mg/kg, followed by a continuous dose of 0.04 mg/kg per hour, which was adjusted every two hours to achieve a target level of sedation at 3-6 on the Ramsay Sedation Scale (RSS); buprenorphine was administered at a constant rate (0.625 microg kg(-1) hr(-1)).

MEASUREMENTS

BIS value, RSS, midazolam dose, body temperature (BT), heart rate, dopamine dose, and mean arterial pressure were recorded every two hours by an independent nurse. Data were analyzed using Spearman rank correlation and the Mann-Whitney U test.

MAIN RESULTS

BIS values decreased depending on depth of sedation; a significant correlation was noted between groups in RSS and BIS. The BIS values at levels of RSS 5 and 6 were significantly lower in Group H than Group M.

CONCLUSION

BIS correlated with sedation depth, with BIS scores in group H than group M at a deep sedation depth.

Assessment of Delirium in the Intensive Care Unit: Nursing Practices And Perceptions

Background Despite practice guidelines promoting delirium assessment in intensive care, few data exist regarding current delirium assessment practices among nurses and how these practices compare with those for sedation assessment.

Objectives To identify current practices and perceptions of intensive care nurses regarding delirium assessment and to compare practices for assessing delirium with practices for assessing sedation.

Methods A paper/Web-based survey was administered to 601 staff nurses working in 16 intensive care units at 5 acute care hospitals with sedation guidelines specifying delirium assessment in the Boston, Massachusetts area.

Results Overall, 331 nurses (55%) responded. Only 3% ranked delirium as the most important condition to evaluate, compared with altered level of consciousness (44%), presence of pain (23%), or improper placement of an invasive device (21%). Delirium assessment was less common than sedation assessment (47% vs 98%, P &lt; .001) and was more common among nurses who worked in medical intensive care units (55% vs 40%, P = .03) and at academic centers (53% vs 13%, P &lt; .001). Preferred methods for assessing delirium included assessing ability to follow commands (78%), checking for agitation-related events (71%), the Confusion Assessment Method for the Intensive Care Unit (36%), the Intensive Care Delirium Screening Checklist (11%), and psychiatric consultation (9%). Barriers to assessment included intubation (38%), complexity of the tool for assessing delirium (34%), and sedation level (13%).

Conclusions Practice and perceptions of delirium assessment vary widely among critical care nurses despite the presence of institutional sedation guidelines that promote delirium assessment.

Experiences of intensive care nurses assessing sedation/agitation in critically ill patients

BACKGROUND

Patients admitted to the intensive care unit (ICU) will more often than not require sedative and analgesic drugs to enable them to tolerate the invasive procedures and therapies caused as a result of their underlying condition and/or necessary medical interventions.

AIM

This article reports a study exploring the perceptions and experiences of intensive care nurses using a sedation/agitation scoring (SAS) tool to assess and manage sedation and agitation amongst critically ill patients. The principle aims and objectives of this study were as follows: to explore nurse's everyday experiences using a sedation scoring tool; to explore and understand nurse's attitudes and beliefs of the various components of assessing and managing sedation among critically ill patients.

METHOD

Using a descriptive qualitative approach, semistructured interviews were carried out with a purposive sample of eight ICU nurses within a district general hospital ICU. The interviews focused on nurses own experiences and perceptions of using a sedation scoring tool in clinical practice. Burnards 14-stage thematic content analysis framework was employed to assist in the data analysis process.

RESULTS

Three key themes emerged that may have implications not only for clinical practice but for further research into the use of the SAS tool. Benefits to patient care as a direct result of using a sedation scoring tool. The concerns of nursing staff. The implications of using such a tool in clinical practice.

CONCLUSION

This paper reinforces the potential benefits to patients as a direct result of implementing the SAS scoring tool and clinical guidelines. Furthermore, it highlights the reluctance of a number of staff to adhere to such guidelines and discusses the concerns regarding less experienced nurses administering sedative agents. Attention was also drawn to the educational requirements of nursing and medical staff when using the SAS scoring tool.

Implementation, reliability testing, and compliance monitoring of the Confusion Assessment Method for the Intensive Care Unit in trauma patients

OBJECTIVE

To implement delirium monitoring, test reliability, and monitor compliance of performing the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) in trauma patients.

DESIGN AND SETTING

Prospective, observational study in a level 1 trauma unit of a tertiary care, university-based medical center.

PATIENTS

Acutely injured patients admitted to the trauma unit between 1 February 2006 and 16 April 2006.

MEASUREMENTS AND RESULTS

Following web-based teaching modules and group in-services, bedside nurses evaluated patients daily for depth of sedation with the Richmond Agitation-Sedation Scale (RASS) and for the presence of delirium with the CAM-ICU. On randomly assigned days over a 10-week period, evaluations by nursing staff were followed by evaluations by an expert evaluator of the RASS and the CAM-ICU to assess compliance and reliability of the CAM-ICU in trauma patients. Following the audit period the nurses completed a postimplementation survey. The expert evaluator performed 1,011 random CAM-ICU assessments within 1h of the bedside nurse's assessments. Nurses completed the CAM-ICU assessments in 84% of evaluations. Overall agreement (kappa) between nurses and expert evaluator was 0.77 (0.721-0.822; p < 0.0001), in TBI patients 0.75 (0.667-0.829; p < 0.0001) and in mechanically ventilated patients 0.62 (0.534-0.704; p < 0.0001). The survey revealed that nurses were confident in performing the CAM-ICU, realized the importance of delirium, and were satisfied with the training that they received. It also acknowledged obstacles to implementation including nursing time and failure of physicians/surgeons to address treatment approaches for delirium.

CONCLUSIONS

The CAM-ICU can be successfully implemented in a university-based trauma unit with high compliance and reliability. Quality improvement projects seeking to implement delirium monitoring would be wise to address potential pitfalls including time complaints and the negative impact of physician indifference regarding this form of organ dysfunction.

Perspectives on sedation assessment in critical care

Multiple studies have been undertaken to show that neurofunction monitors can correlate to objective sedation assessments. Showing a correlation between these 2 patient assessments tools may not be the correct approach for validation of neurofunction monitors. Two different methods of assessing 2 different modes of the patient's response to sedation should not be expected to precisely correlate unless the desire is to replace one method with the other. We provide a brief summary of several sedation scales, physiologic measures and neurofunction monitoring tools, and correlations literature for bispectral index monitoring, and the Ramsay Scale and the Sedation Agitation Scale. Neurofunction monitors provide near continuous information about a different domain of the sedation response than intermittent observational assessments. Further research should focus on contributions from this technology to the improvement of patient outcomes when neurofunction monitoring is used as a complement, not a replacement, for observational methods of sedation assessment.

Survey of sedation practices during noninvasive positive-pressure ventilation to treat acute respiratory failure

OBJECTIVES

Noninvasive positive-pressure ventilation (NPPV) is increasingly used in patients with acute respiratory failure, but few data exist regarding current sedation practices during NPPV. We sought to characterize current practices and attitudes regarding sedation during NPPV.

DESIGN

Cross-sectional Web-based survey.

SETTING

Medical institutions.

PARTICIPANTS

Physician members of the American College of Chest Physician's Critical Care Network (n = 2,656) and the European Respiratory Society's Assembly of Critical Care (n = 339).

INTERVENTIONS

Survey.

MEASUREMENTS AND MAIN RESULTS

Of the 790 of 2,985 (27%) of physicians who responded, 15%, 6%, and 28% never used sedation, analgesia, or hand restraints any of the time for NPPV patients, respectively, and the large majority reported using these interventions in < or =25% of patients. Sedation, analgesia, and hand restraints were more commonly used by North Americans than Europeans (41% vs. 24% for sedation, 48% vs. 35% for analgesia, and 27% vs. 16% for hand restraints, all p < .01) and critical care vs. noncritical care physicians (42% vs. 24% for sedation and 50% vs. 34% for analgesia, all p < .01). A benzodiazepine alone was the most preferred (33%), followed by an opioid alone (29%). Europeans were less likely to use a benzodiazepine alone (25% vs. 39%, p < .001) but more likely to use an opioid alone (37% vs. 26%, p < .009). Sedation was usually administered as an intermittent intravenous bolus, outside of a protocol, and was assessed by nurses using clinical end points rather than a sedation scale.

CONCLUSIONS

Most physicians infrequently use sedation and analgesic therapy for NPPV to treat acute respiratory failure, but practices vary widely within and between specialties and geographic regions.

Sedation and analgesia in the intensive care unit: evaluating the role of dexmedetomidine

PURPOSE

A review highlighting the application of sedatives and analgesics in the intensive care unit (ICU) setting, with a focus on the use of dexmedetomidine, is presented.

SUMMARY

Relevant and applicable clinical trials that resulted from a search of the literature from 1966 to July 2006 using key search terms such as dexmedetomidine, intensive care unit, sedation, delirium, and analgesia were evaluated. Many agents have been evaluated in the search of the optimal regimen for sedation and analgesia in the ICU, including opioids, benzodiazepines, propofol, and antipsychotic agents. Dexmedetomidine has demonstrated efficacy as a sedative analgesic on the basis of its ability to lower opioid, benzodiazepine, and propofol requirements in clinical trials. The role of dexmedetomidine in ICU clinical practice is limited because of a lack of mortality and other morbidity endpoints, such as ICU length of stay, hospital length of stay, time to extubation, long-term complications after discharge from the ICU, and delirium. The most commonly reported adverse effects of dexmedetomidine are secondary to its effects as an alpha(2)-receptor agonist and are cardiac in nature. A detailed cost analysis may be warranted to justify the relatively high acquisition cost of dexmedetomidine.

CONCLUSION

Dexmedetomidine may be an effective agent for ICU sedation and analgesia. However, the lack of clinically relevant endpoints in trials, the concern about adverse cardiovascular effects, and the relatively high acquisition cost of this drug limit its use to a select number of patients who may benefit from its distinguished mechanism of action.

Clinical Pharmacokinetic Monitoring of Midazolam in Critically Ill Patients

Midazolam is a commonly used sedative in critically ill, mechanically ventilated patients in intensive care unit (ICU) settings worldwide. We used a nine-step decision-making algorithm to determine whether therapeutic monitoring of midazolam in the ICU is warranted. Midazolam has a higher clearance and shorter half-life than other benzodiazepines, and prolonged sedation is achieved with continuous infusion. There appears to be very good correlation between plasma concentrations of both midazolam and its active metabolite, alpha1-hydroxymidazolam, and the degree of sedation. However, due to high interpatient variability, it is not possible to predict the level of sedation in any given individual based on plasma concentration of midazolam or its metabolites. Moreover, no simple and practical assay is available to quantitate midazolam plasma concentrations in the acute ICU setting. Many scales are available to assess the sedative effects of midazolam. Because the plasma concentration of midazolam required to achieve a constant level of sedation is highly variable, it is usually more prudent for the clinician to monitor for sedation with a validated clinical scale than by plasma concentrations alone. Various physiologic parameters, including age-related effects, compromised renal function, and liver dysfunction affect the pharmacokinetics of midazolam and alpha1-hydroxymidazolam. Although routine drug monitoring for all critically ill patients receiving midazolam is not recommended, this practice is likely beneficial in patients with neurologic damage in whom sedation cannot be assessed and in patients who have renal failure with a prolonged time to awakening.

Stressful experiences in relation to depth of sedation in mechanically ventilated patients

In mechanically ventilated patients, sedatives and analgesics are commonly used to ensure comfort, but there is no documented knowledge about the impact of depth of sedation on patients' perception of discomfort. The aim of this study was, therefore, to investigate the relationship between stressful experiences and intensive care sedation, including the depth of sedation. During 18 months, 313 intubated mechanically ventilated adults admitted to two general intensive care units (ICU) for more than 24 h were included. Patients (n = 250) were interviewed on the general ward 5 days after ICU discharge using the ICU Stressful Experiences Questionnaire. Patient data including sedation scores as measured by the Motor Activity Assessment Scale (MAAS) were collected from hospital records after the interview. Of the 206 patients with memories of the intensive care, 82% remembered at least one experience as quite a bit or extremely bothersome. Multivariate analyses showed that higher proportion of MAAS score 3 (indicating more periods of wakefulness), longer ICU stay and being admitted emergent were factors associated with remembering stressful experiences of the ICU as more bothersome. The findings indicate that the depth of sedation has an impact on patients' perception of stressful experiences and that light sedation compared with heavy seems to increase the risk of perceiving experiences in the ICU as more bothersome. In reducing discomfort, depth of sedation and patient comfort should be assessed regularly, non-pharmacological interventions taken into account and the use of sedatives and analgesics adapted to the individual requirements of the patient.

Palliative Sedation Therapy in the Last Weeks of Life: A Literature Review and Recommendations for Standards

PURPOSE

Palliative sedation therapy (PST) is a controversial issue. There is a need for internationally accepted definitions and standards.

METHODS

A systematic review of the literature was performed by an international panel of 29 palliative care experts. Draft papers were written on various topics concerning PST. This paper is a summary of the individual papers, written after two meetings and extensive e-mail discussions.

RESULTS

PST is defined as the use of specific sedative medications to relieve intolerable suffering from refractory symptoms by a reduction in patient consciousness, using appropriate drugs carefully titrated to the cessation of symptoms. The initial dose of sedatives should usually be small enough to maintain the patients' ability to communicate periodically. The team looking after the patient should have enough expertise and experience to judge the symptom as refractory. Advice from palliative care specialists is strongly recommended before initiating PST. In the case of continuous and deep PST, the disease should be irreversible and advanced, with death expected within hours to days. Midazolam should be considered first-line choice. The decision whether or not to withhold or withdraw hydration should be discussed separately. Hydration should be offered only if it is considered likely that the benefit will outweigh the harm. PST is distinct from euthanasia because (1) it has the intent to provide symptom relief, (2) it is a proportionate intervention, and (3) the death of the patient is not a criterion for success. PST and its outcome should be carefully monitored and documented.

CONCLUSION

When other treatments fail to relieve suffering in the imminently dying patient, PST is a valid palliative care option.

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.

[Knowledge and application level of the Ramsay Scale by Mexican nurses specialized in intensive care]

INTRODUCTION

Among the intensive care specialized nursing staff, knowing the sedation level of the patient under their responsibility is of crucial importance. The present study evaluated the knowledge that nurses specialized in intensive care (NSIC) have on the Ramsay Scale (RS) and the way in which they apply it.

MATERIAL AND METHODS

Those personnel who were developing their activity in the intensive care units (ICU) of four public hospitals of the cities of Merida, Yucatan, Mexico were enrolled during May 2003. The information was obtained by applying an expressly designed questionnaire that contained both demographic endpoints (age, years of experience as NSIC and type of ICU) and those related with the RS (clinical components that it evaluates, operative definitions, frequency of use per week or day). 95% (95% CI) confidence intervals were applied and odds ratio (OR) was used to determined the likelihood of the event.

RESULTS

Of the 60 nurses interviewed, 75% did not know the RS. Age was a significant factor associated with its knowledge, since 11 of 23 with an age equal to or less than 38 years (47.8%) and 4 of 37 over 38 years (10.8%) knew what it evaluated (OR of 4 for the group of lower age, 95% CI 1.5 to 12.3, p = 0.002). Of 15 NSIC who knew what it evaluated, 9 (60%) also knew its operative definitions, and stated that they applied it adequately per day.

CONCLUSIONS

In this sample, there is an elevated percentage of NSIC who did not know the RS. Age was the factor associated with lack of knowledge.

Principles and practices of medication safety in the ICU

Medication errors are a significant public health problem in United States hospitals. Patients in the ICU are at particular risk for medication errors because of the characteristics of an ICU and the nature of its patients. This article reviews the principles of medication safety and applies these principles to the ICU, and suggests safe practices to improve medication safety in the ICU.

Memory in relation to depth of sedation in adult mechanically ventilated intensive care patients

OBJECTIVE

To investigate the relationship between memory and intensive care sedation.

DESIGN AND SETTING

Prospective cohort study over 18[Symbol: see text]months in two general intensive care units (ICUs) in district university hospitals.

PATIENTS

313 intubated mechanically ventilated adults admitted for more than 24 h, 250 of whom completed the study.

MEASUREMENTS

Patients (n=250) were interviewed in the ward 5 days after discharge from the ICU using the ICU Memory Tool. Patient characteristics, doses of sedative and analgesic agents, and sedation scores as measured by the Motor Activity Assessment Scale (MAAS) were collected from hospital records after the interview.

RESULTS

Patients with no recall (18%) were significantly older, had higher baseline severity of illness, and experienced fewer periods of wakefulness (median proportion of MAAS score 3; 0.37 vs. 0.70) than those who had memories of the ICU (82%). Multivariate analyses showed that increasing proportion of MAAS 0-2 and older age were significantly associated with having no recall. Patients with delusional memories (34%) had significantly longer ICU stay (median 6.6 vs. 2.2 days), higher baseline severity of illness, higher proportions of MAAS scores 4-6, and more administration of midazolam than those with recall of the ICU without delusional memories.

CONCLUSIONS

Heavy sedation increases the risk of having no recall, and longer ICU stay increases the risk of delusional memories. The depth of sedation during total ICU stay as recorded with the MAAS may predict the probability of having memories of the ICU.

The reliability and validity of a new and simple method to measure sedation levels in intensive care patients: A pilot study

BACKGROUND

Since more sophisticated ventilation techniques have enabled patients to comply with the ventilator with little or no sedation, deep sedation levels can easily be avoided. However, successful ventilation techniques also expanded the treatment possibilities for more severely ill patients who require deeper sedation levels. We developed a new sedation score to improve the prevention of oversedation and to simplify scoring practice in the intensive care unit (ICU).

OBJECTIVE

The study's objective was to establish the validity and reliability of a new sedation score (Sedic score) for critically ill, sedated adult patients.

METHODS

We prospectively evaluated the reliability and validity of the Sedic score. The study took place in a 30-bed ICU in a university teaching hospital. Forty-six consecutive mechanically ventilated and sedated ICU patients were included. The constructed scale consists of five levels of stimuli and five levels of responses. Sedation levels are defined by the sum of stimulus and response. The reliability of the Sedic score was assessed by simultaneous measurement by the research nurse and attending nurse (n=70). VALIDITY was expressed as (1) the hierarchic relation between stimulus and response (n=443), (2) the prediction of wake-up time by the Sedic score (n=46), and (3) the association between the Sedic score and the Ramsay scale (n=88).

RESULTS

The method showed excellent reliability.

VALIDITY

Weighted kappa between stimulus and response was .82. Multivariate analysis: (recovery time as independent variable) regression line (Y=-2.53+ 2.16 * beta; P<.001) (r2=42%). Correlation between the Sedic scores and the Ramsay scores was r(s) .74 (P=.01). Sixty-seven percent of the patients with a maximum Ramsay score of 6 had scores ranging between 6 and 10 on the Sedic scale, indicating that the Ramsay scale has a serious ceiling effect.

CONCLUSION

The Sedic score demonstrates sufficient reliability and validity, and correlates well with wake-up time. It allows for frequent use by nurses to avoid oversedation in patients.

Toward Solving the Sedation-Assessment Conundrum: Bispectral Index Monitoring and Sedation Interruption

The sedation-assessment conundrum is defined by two diametrically opposed goals: to maintain an appropriate level of sedation, and to obtain a comprehensive neurologic examination that most accurately reflects the patient's neurologic status. A case presentation leads to a discussion of over-sedation and under-sedation issues that impact the care of critically ill patients. This information is useful in understanding the many methods of assessing sedation and interpreting individualized patient responses to sedation. The use of bi-spectral index monitoring and periods of sedation interruption are discussed within the context of addressing the sedation-assessment conundrum.

Sedation Assessment in Critically Ill Adults: 2001–2004 Update

OBJECTIVE

To review recently published literature on the validity and reliability of sedation assessment tools in critically ill adults and evaluate the potential advantages and disadvantages of each.

DATA SOURCES

A computerized search of MEDLINE and PubMed (2001–May 2004) was conducted.

STUDY SELECTION AND DATA EXTRACTION

Sedation assessment tools used in adult intensive care units (ICUs) were identified.

DATA SYNTHESIS

Six subjective and 3 objective assessment tools were identified. Four subjective assessment tools have reliability and 4 have validity data published that were not previously available. There are reliability data to further support the use of the previously published Motor Activity Assessment Scale. Additional reliability data exist for the Ramsay Scale and Glasgow Coma Scale. Conflicting evidence is available with the use of the Bispectral Index monitor in the ICU. Recently, the Patient State Index and Auditory Evoked Potentials were introduced for objective monitoring in critically ill patients.

CONCLUSIONS

Increasing data on sedation assessment were published over the last few years, probably in response to supporting evidence that goal-driven sedation therapy improves patient outcomes. Reliability and/or validity testing exists for many of these scales. Several useful tools are available to guide sedation therapy in critically ill patients.

Development of a risk assessment tool for deliberate self-extubation in intensive care patients

OBJECTIVE

To develop a risk stratification scheme for deliberate self-extubation in intensive care patients.

DESIGN

A nested case-control study.

SETTING

Four surgical ICUs, one medical ICU, one coronary care unit, and one emergency department of a tertiary care center.

MEASUREMENT

In a 3-month period, the number of ventilation periods, ventilation days, and unplanned extubations were recorded. Potential determinants of unplanned extubation were assessed with a translated (English to Dutch) and modified version of the "Unplanned Extubation Data Collection Tool."

PATIENTS

Clinical and demographic characteristics and circumstances of the 26 unplanned extubations were compared with those of 48 randomly selected control patients who did not experience unplanned extubation.

RESULTS

The incidence of unplanned extubation was 4.2%, corresponding to 0.68 unplanned extubations per 100 ventilation days. The incidence was substantially lower at surgical ICUs (2.6%) compared with that at medical ICU/CCUs (9.5%). Multiple logistic regression analysis revealed that patients with a low sedation level (Bloomsbury Sedation Score) and a higher degree of consciousness (Glasgow Coma Scale) were at higher risk for deliberate self-extubation. The explained variance of this model including these factors was 67.3%.

CONCLUSION

Based on the risk factors identified, a risk assessment tool was developed. Systematic administration of the Bloomsbury Sedation Score and the Glasgow Coma Scale, and the use of the stratification scheme, allows identification of patients at risk. Appropriate reduction of sedative drugs during weaning, a timely extubation, and increased surveillance in patients identified to be at risk are possible interventions to diminish the number of unplanned extubations.

Intensive care sedation of mechanically ventilated patients: a national Swedish survey

Sedation in critically ill patients is a complex issue and at the same time an important concept for ensuring patient comfort. The aim of this study was to review the current practice of sedation for patients on mechanical ventilation in Swedish intensive care units (ICUs). Questionnaires were sent by post to head nurses in 89 ICUs with mechanically ventilated patients. By August 2000, 87 (98%) questionnaires had been returned. The results show that mechanically ventilated patients were routinely sedated in 91% of ICUs. Midazolam or propofol in combination with an opioid were the drugs preferred by 76%. Heavy sedation was most usual in 63% of ICUs but, when asked about the sedation level preferred by nurses, 78% chose light sedation (P=0.001). Only 16% used sedation scales. This study indicates that local habits and personal attitudes seem to have a great impact on sedation routines. It therefore appears worthwhile for ICUs to review their practice and, if necessary, to consider implementing sedation scales and sedation guidelines. Research pertaining to potential complications and patient comfort in relation to different sedation levels as well as further validation of the efficacy of sedation scales is needed.

The Impact of Bispectral Index Monitoring on Rates of Propofol Administration

The purpose of this article is to examine the efficacy of Bispectral Index (BIS) monitoring as a tool for adjusting the amount of propofol patients receive to maintain a safe and adequate level of sedation in a neurocritical care setting. The BIS monitor is utilized as an adjunct for anesthesia monitoring in the operating room setting and is currently being investigated as a tool for objective sedation monitoring in the critical care setting. 1-6 Sedation is discussed in terms of patient safety and comfort. A secondary data analysis was used to test the hypothesis that BIS monitoring provides a more objective form of sedation assessment that will lead to a decrease in overall rates of propofol administration and fewer incidences of oversedation. Data were abstracted from a quality improvement study of propofol use adjusted to BIS values in patients whose sedation levels were previously adjusted to a goal Ramsay score. The results suggest that there are potential benefits to incorporating BIS into routine sedation assessment in the neurocritical care setting.

Sedation in neurointensive care: advances in understanding and practice

PURPOSE OF REVIEW

To evaluate the rationale and the pharmacologic options for sedating neurointensive care patients.

RECENT FINDINGS

Sedation is a fundamental element in the neurointensive care unit. Even if the sedative strategy in the neurointensive care unit shares the same general aims with intensive care, the characteristics of the patients in the neurointensive care unit pose other unique challenges and some specific indications. The primary aim of neurointensive care is to maintain adequate cerebral perfusion pressure, to control intracranial pressure, and to maintain an adequate mean arterial pressure. Reducing the brain's metabolic demand is an important treatment strategy, and analgesic and sedative agents are used to prevent undesirable increases in intracranial pressure. There are many different pharmacologic agents available, each with distinct advantages and disadvantages.

SUMMARY

The pharmacokinetic and pharmacologic effects of the available sedatives used in neurointensive care patients are reviewed.

Sequential use of midazolam and propofol for long-term sedation in postoperative mechanically ventilated patients

Acute withdrawal syndromes, including agitation and a long weaning time, are common adverse effects after long-term sedation with midazolam. We performed this study to determine whether the sequential use of midazolam and propofol could reduce adverse effects as compared with midazolam alone. We studied 26 patients receiving mechanical ventilation for three or more days after surgery. Patients were randomly assigned to two groups. In Group M, patients were sedated with midazolam alone. In Group M-P, midazolam was switched to propofol approximately 24 h before the expected stopping of sedation. The level of sedation was maintained at 4 or 5 on the Ramsay sedation scale. The sedation agitation scale was evaluated for 24 h after extubation. The recovery time from stopping of sedation to extubation was significantly shorter in Group M-P (1.3 +/- 0.4 h) compared with Group M (4.0 +/- 2.4 h). The incidence of agitation in Group M-P (8%) was significantly less frequent than that in Group M (54%). The results indicate that sequential use of midazolam and propofol for long-term sedation could reduce the incidence of agitation compared with midazolam alone.

IMPLICATIONS

Our study indicates that sequential use of midazolam and propofol could reduce the incidence of agitation compared with midazolam alone.