Interrater reliability of 2 sedation scales in a medical intensive care unit: a preliminary report

Association Between Processed Electroencephalogram-Based Objectively Measured Depth of Sedation and Cerebrovascular Response: A Systematic Scoping Overview of the Human and Animal Literature

Background: Current understanding of the impact that sedative agents have on neurovascular coupling, cerebral blood flow (CBF) and cerebrovascular response remains uncertain. One confounding factor regarding the impact of sedative agents is the depth of sedation, which is often determined at the bedside using clinical examination scoring systems. Such systems do not objectively account for sedation depth at the neurovascular level. As the depth of sedation can impact CBF and cerebral metabolism, the need for objective assessments of sedation depth is key. This is particularly the case in traumatic brain injury (TBI), where emerging literature suggests that cerebrovascular dysfunction dominates the burden of physiological dysfunction. Processed electroencephalogram (EEG) entropy measures are one possible solution to objectively quantify depth of sedation. Such measures are widely employed within anesthesia and are easy to employ at the bedside. However, the association between such EEG measures and cerebrovascular response remains unclear. Thus, to improve our understanding of the relationship between objectively measured depth of sedation and cerebrovascular response, we performed a scoping review of the literature.

Methods: A systematically conduced scoping review of the existing literature on objectively measured sedation depth and CBF/cerebrovascular response was performed, search multiple databases from inception to November 2020. All available literature was reviewed to assess the association between objective sedation depth [as measured through processed electroencephalogram (EEG)] and CBF/cerebral autoregulation.

Results: A total of 13 articles, 12 on adult humans and 1 on animal models, were identified. Initiation of sedation was found to decrease processed EEG entropy and CBF/cerebrovascular response measures. However, after this initial drop in values there is a wide range of responses in CBF seen. There were limited statistically reproduceable associations between processed EEG and CBF/cerebrovascular response. The literature body remains heterogeneous in both pathological states studied and sedative agent utilized, limiting the strength of conclusions that can be made.

Conclusions: Conclusions about sedation depth, neurovascular coupling, CBF, and cerebrovascular response are limited. Much further work is required to outline the impact of sedation on neurovascular coupling.

A review of sedation scales for the cardiac catheterization laboratory

PURPOSE

Sedation scales have the potential to facilitate effective procedural sedation and analgesia in the cardiac catheterization laboratory (CCL). For this potential to become realized, a scale that is suitable for use in the CCL either needs to be identified or developed.

DESIGN

A structured review strategy was applied.

METHODS

To identify sedation scales, a review of Medline and CINHAL was conducted.

FINDINGS

One sedation scale for the CCL, the North American Society for Pacing and Electrophysiology Sedation Scale, and 15 intensive care unit (ICU) scales met the inclusion and exclusion criteria. Analysis of the scale's item structures and psychometric properties was then performed.

CONCLUSION

None of these scales were deemed suitable for use in the CCL. As such, further research is required to develop a new scale. The new scale should consist of more than one item to make it more effective for tracking the patient's response to medications. Specific tests required to conduct a rigorous evaluation of the new scale's psychometric properties are outlined in this article.

The validity, reliability, responsiveness and applicability of observation sedation-scoring instruments for use with adult patients in the emergency department: a systematic literature review

AIM

This paper reports a systematic literature review examining the range of published observational sedation-scoring instruments available in the assessment, monitoring and titration of continuous intravenous sedation to critically ill adult patients in the Emergency Department, and the extent to which validity, reliability, responsiveness and applicability of the instruments has been addressed.

BACKGROUND

Emergency nurses are increasingly responsible for the ongoing assessment, monitoring and titration of continuous intravenous sedation, in addition to analgesia for the critically ill adult patient. One method to optimise patient sedation is to use a validated observational sedation-scoring tool. It is not clear however what the optimal instrument available is for use in this clinical context.

METHODS

A systematic literature review methodology was employed. A range of electronic databases were searched for the period 1946-2013. Search terms incorporated "sedation scale", "sedation scoring system", "measuring sedation", and "sedation tool" and were used to retrieve relevant literature. In addition, manual searches were conducted and articles retrieved from those listed in key papers. Articles were assessed using the Critical Appraisal Skills Program (CASP) making sense of evidence tools.

RESULTS

A total of 27 observational sedation-scoring instruments were identified. Sedation-scoring instruments can be categorised as linear or composite, the former being the most common. A wide variety of patient behaviours are used within the instruments to measure depth and quality of patient sedation. Typically sedation-scoring instruments incorporated three patient behaviours, which were then rated to generate a numerical score. The majority of the instruments have been subjected to validity and reliability testing, however few have been examined for responsiveness or applicability.

CONCLUSIONS

None of the 27 observational sedation-scoring instruments were designed or trialled within ED. The Richmond Agitation and Assessment Scale was identified as most suitable to be trialled prospectively within an Australian ED.

Psychometric analysis of subjective sedation scales in critically ill adults

OBJECTIVE

To describe and analyze the development and psychometric properties of subjective sedation scales developed for critically ill adult patients.

DATA SOURCES

PubMed, MEDLINE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, CINAHL, Scopus, ISI Web of Science, and the International Pharmaceutical Abstracts.

STUDY SELECTION

English-only publications through December 2012 with at least 30 patients older than 18 years, which included the key words of adult, critically ill, subjective sedation scale, sedation scale, validity, and reliability.

DATA EXTRACTION

Two independent reviewers evaluated the psychometric properties using a standardized sedation scale psychometric scoring system.

DATA SYNTHESIS

Among the 19,000+ citations extracted for the 2013 Society of Critical Care Medicine's Clinical Practice Guidelines for the Management of Pain, Agitation and Delirium and from December 2010 to 2012, 36 articles were identified compassing 11 sedation scales. The scale development process, psychometric properties, feasibility, and implementation of sedation scales were analyzed using a 0-20 scoring system. Two scales demonstrated scores indicating "very good" published psychometric properties: Richmond Agitation-Sedation Scale (19.5) and the Sedation-Agitation Scale (19). Scores with "moderate" properties include the Vancouver Interaction and Calmness Scale (14.3), Adaptation to the Intensive Care Environment (13.7), Ramsay Sedation Scale (13.2), Minnesota Sedation Assessment Tool (13), and the Nursing Instrument for the Communication of Sedation (12.8). Scales with "low" properties included the Motor Activity Assessment Scale (11.5) and the Sedation Intensive Care Score (10.5). The New Sheffield Sedation Scale (8.5) and the Observer's Assessment of Alertness/Sedation Scale (3.7) demonstrated "very low" published properties.

CONCLUSIONS

Based on the current literature, and using a predetermined psychometric scoring system, the Richmond Agitation-Sedation Scale and the Sedation-Agitation Scale are the most valid and reliable subjective sedation scales for use in critically ill adult patients.

Clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit

OBJECTIVE

To revise the "Clinical Practice Guidelines for the Sustained Use of Sedatives and Analgesics in the Critically Ill Adult" published in Critical Care Medicine in 2002.

METHODS

The American College of Critical Care Medicine assembled a 20-person, multidisciplinary, multi-institutional task force with expertise in guideline development, pain, agitation and sedation, delirium management, and associated outcomes in adult critically ill patients. The task force, divided into four subcommittees, collaborated over 6 yr in person, via teleconferences, and via electronic communication. Subcommittees were responsible for developing relevant clinical questions, using the Grading of Recommendations Assessment, Development and Evaluation method (http://www.gradeworkinggroup.org) to review, evaluate, and summarize the literature, and to develop clinical statements (descriptive) and recommendations (actionable). With the help of a professional librarian and Refworks database software, they developed a Web-based electronic database of over 19,000 references extracted from eight clinical search engines, related to pain and analgesia, agitation and sedation, delirium, and related clinical outcomes in adult ICU patients. The group also used psychometric analyses to evaluate and compare pain, agitation/sedation, and delirium assessment tools. All task force members were allowed to review the literature supporting each statement and recommendation and provided feedback to the subcommittees. Group consensus was achieved for all statements and recommendations using the nominal group technique and the modified Delphi method, with anonymous voting by all task force members using E-Survey (http://www.esurvey.com). All voting was completed in December 2010. Relevant studies published after this date and prior to publication of these guidelines were referenced in the text. The quality of evidence for each statement and recommendation was ranked as high (A), moderate (B), or low/very low (C). The strength of recommendations was ranked as strong (1) or weak (2), and either in favor of (+) or against (-) an intervention. A strong recommendation (either for or against) indicated that the intervention's desirable effects either clearly outweighed its undesirable effects (risks, burdens, and costs) or it did not. For all strong recommendations, the phrase "We recommend …" is used throughout. A weak recommendation, either for or against an intervention, indicated that the trade-off between desirable and undesirable effects was less clear. For all weak recommendations, the phrase "We suggest …" is used throughout. In the absence of sufficient evidence, or when group consensus could not be achieved, no recommendation (0) was made. Consensus based on expert opinion was not used as a substitute for a lack of evidence. A consistent method for addressing potential conflict of interest was followed if task force members were coauthors of related research. The development of this guideline was independent of any industry funding.

CONCLUSION

These guidelines provide a roadmap for developing integrated, evidence-based, and patient-centered protocols for preventing and treating pain, agitation, and delirium in critically ill patients.

Analytic reviews: managing the agitated patient in the ICU: sedation, analgesia, and neuromuscular blockade

Physical and psychological distress is exceedingly common among critically ill patients and manifests generically as agitation. The dangers of over- and undertreatment of agitation have been well described, and the intensive care unit (ICU) physician must strike a balance in the fast-paced, dynamic ICU environment. Identification of common reversible etiologies for distress may obviate the need for pharmacologic therapy, but most patients receive some combination of sedative, analgesic, and neuroleptic medications during the course of their critical illness. As such, understanding key pharmacologic features of commonly used agents is critical. Structured protocols and objective assessment tools can optimize drug delivery and may ultimately improve patient outcomes by reducing ventilator days, ICU length of stay, and by reducing cognitive dysfunction.

[Analysis of 4 sedation rating scales in the critical patient]

BACKGROUND

This study aimed to verify the relationship between different Sedation Rating Scales (SRSs) for critical patients on mechanical ventilation and to know the relationship between the SRSs, clinical information and the dose of sedative and analgesia drugs (SAD).

MATERIAL AND METHODS

A longitudinal, prospective analytic pilot study conducted in a Medical-Surgical Intensive Care Unit of a tertiary hospital from October-December 2006. The sample included patients who required administration of SAP and mechanical ventilation. The following biological parameters and scales were evaluated: patient's demographics, RAMSAY, Sedation Agitation Scale (SAS), Richmond Agitation Sedation Scale (RASS), Motor Activity Assessment Scale (MASS), SAD dose, mean blood pressure, cardiac rate, pupil diameter and respiratory frequency. Spearman coefficient of interrelation was used to compare the relationship between the different scales.

RESULTS

A total of 2.412 measurements were made for each variable: SRS, clinical information and SAD dose in 30 patients with different diseases, 63 % males, age 52 +/- 19 years, APACHEII 24 +/- 8, SAPSII 44 +/- 16, with an ICU mortality UCI 34 %. Median and IQ range of stay in ICU 15.5 and 20 days, of mechanical ventilation 9 and 14 days, of SAD 6 and 5.5 days and of paralyzing drugs (PD) 2 and 5 days, respectively. Interrelation was detected between all the SRSs, with p < 0.0001. The relationship between SAS, RASS and MASS was direct, whereas these were related inversely to RAMSAY. No evidence of interrelation was found between the SRSs, the clinical information and the SAD doses.

CONCLUSION

The RAMSAY scale that has not been validated in ICU patients has a strong interrelation with the other already validated SRSs. SRSs are subjective and do not correlate with the clinical information and the SAD doses, probably due to the sample's small size and heterogeneity.

[Sedation and analgesia assessment tools in ICU patients]

Sedative and analgesic treatment administered to critically ill patients need to be regularly assessed to ensure that predefinite goals are well achieved as the risk of complications of oversedation is minimized. In most of the cases, which are lightly sedation patients, the goal to reach is a calm, cooperative and painless patient, adapted to the ventilator. Recently, eight new bedside scoring systems to monitor sedation have been developed and mainly tested for reliability and validity. The choice of a sedation scale measuring level of consciousness, could be made between the Ramsay sedation scale, the Richmond Agitation Sedation scale (RASS) and the Adaptation to The Intensive Care Environment scale-ATICE. The Behavioral Pain Scale (BPS) is a behavioral pain scale. Two of them have been tested with strong evidence of their clinimetric properties: ATICE, RASS. The nurses'preference for a convenient tool could be defined by the level of reliability, the level of clarity, the variety of sedation and agitation states represented user friendliness and speed. In fine, the choice between a simple scale easy to use and a well-defined and complex scale has to be discussed and determined in each unit. Actually, randomized controlled studies are needed to assess the potential superiority of one scale compared with others scales, including evaluation of the reliability and the compliance to the scale. The usefulness of the BIS in ICU for patients lightly sedated is limited, mainly because of EMG artefact, when subjective scales are more appropriated in this situation. On the other hand, subjective scales are insensitive to detect oversedation in patients requiring deep sedation. The contribution of the BIS in deeply sedation patients, patients under neuromuscular blockade or barbiturates has to be proved. Pharmacoeconomics studies are lacking.

Staff perceptions on the use of a sedation protocol in the intensive care setting

Sedation protocols are increasingly being investigated as a method of achieving improved patient outcomes whilst guiding the decision making of both nursing and medical practitioners. However, only a limited number of studies have investigated the perceptions of staff towards a sedation protocol during its implementation. This study was designed to survey the perceptions of staff regarding the implementation of a sedation protocol in an Australian intensive care unit (ICU). Questionnaires were distributed to all multidisciplinary team members who had used the sedation protocol. The response rate was 50% (n=70). The questionnaire combined the use of visual analogue scales plus a comments section to obtain qualitative data. The results revealed that staff perceived sedation management to be enhanced with the use of a protocol and therefore should be incorporated into routine clinical practice. Staff perceived that providing clear guidelines that facilitated decision making and assisted beginner practitioners enhanced sedation management. In addition, there was a perceived improvement in the patient outcomes, including a decrease in the frequency of over-sedation resulting in a reduced ICU stay. Positive perceptions may assist in the introduction of other interventional protocols. Other protocols may target areas where variability in clinical decision making exists, despite research evidence that supports specific therapeutic interventions. Further studies addressing protocol implementation for clinical interventions are warranted in other ICU settings.

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.

"Between the fixed and the changing": examining and comparing reliability and validity of 3 sedation-agitation measuring scales

The goal of the study was to compare the reliability and validity of 3 Sedation Agitation Scale. Two nurses and a physician conducted 130 observations simultaneously. They found an excellent interrater reliability in the Richmond Agitation Sedation Scale (r>0.86), and high correlations between the Richmond Agitation Sedation Scale and the Sedation Agitation Scale and Visual Analog Scale scales (r=0.92, r=0.85). The research findings will help to assert Richmond Agitation Sedation Scale as a daily assessment tool in the intensive care unit, and it will pave the way for construction a sedation protocol according to the Richmond Agitation Sedation Scale level.

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.

Use of a Behavioural Pain Scale to assess pain in ventilated, unconscious and/or sedated patients

Current empirical evidence supports claims that pain in sedated, unconscious Intensive Care Unit (ICU) patients is underrated and under-treated. Given the severity of ICU patients' illness pain management, whilst important, may not be considered a priority and therefore can be easily overlooked. The aim of this study was to validate the Behavioural Pain Scale (BPS) for the assessment of pain in critically ill patients by evaluating facial expressions, upper limb movements and compliance with mechanical ventilation.

METHODS

A prospective, descriptive repeated measures study design was used to assess the validity and reliability of the BPS for assessing pain in critically ill patients undergoing routine painful (repositioning) and non-painful (eye care) procedures.

RESULTS

An average of 73% of BPS scores increased (indicating pain) after patients were repositioned, as opposed to 14% after eye care. This increase was statistically significant for repositioning (p < 0.003) but not for eye care (p > 0.3). The odds of an increase in BPS between pre- and post-procedure assessments was more than 25 times higher for repositioning compared with eye care (p < 0.0001), after controlling for analgesics and sedatives.

CONCLUSION

The BPS was found to be a valid and reliable tool in the assessment of pain in the unconscious sedated patient. Results also highlighted that traditional pain indicators, such as fluctuations in haemodynamic parameters, are not always an accurate measure for the assessment of pain in unconscious patients and as such more objective pain assessment measures are essential. Finally, further validation of the BPS and identification of other painful routine procedures is needed to enhance pain management delivery for unconscious patients.

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.

Severe agitation among ventilated medical intensive care unit patients: frequency, characteristics and outcomes

OBJECTIVE

To determine the frequency, characteristics and outcomes of severe agitation among ventilated medical intensive care unit (MICU) patients.

DESIGN

Prospective cohort study.

SETTING

Eighteen-bed MICU in 964-bed tertiary care center.

PATIENTS

All ventilated patients, aged 18 years or older and admitted for more than 24 h between January 1, 2001 and May 8, 2001.

INTERVENTIONS

None.

MEASUREMENTS

Data were collected daily by concurrent chart abstractions. Variables included sociodemographic, clinical, laboratory, pharmacologic and non-pharmacologic interventions, ventilator settings and adverse events. Severe agitation, the main outcome variable, was defined as two or more Motor Activity Assessment Scale (MAAS) scores above 4 in a 24-h period and sedative and/or narcotic doses above the established sedation and analgesia protocol or a combination of two or more sedatives.

RESULTS

Twenty-three (16.1%) of 143 enrolled patients exhibited severe agitation. Agitated patients were younger (hazard ratio [HR] 1.32), more likely to be admitted from an outside hospital ICU (HR 2.48), had lower pH (HR 1.55) and PaO(2)/FIO(2) less than 200 mmHg (HR 2.59). Agitated patients had longer MICU stays (median 12 versus 5 days, p<0.0001) and more ventilator days (median 14 versus 6, p<0.0001). Agitated patients were more likely to self-extubate (26% versus 6%, p=0.002). Benzodiazepines, narcotics and neuromuscular blocking agents were administered more frequently and at higher doses, but haloperidol was not.

CONCLUSION

Severe agitation occurs commonly in critically ill patients and is associated with adverse events including longer ICU stays, duration of mechanical ventilation and self-extubation.

The Richmond Agitation-Sedation Scale: validity and reliability in adult intensive care unit patients

Sedative medications are widely used in intensive care unit (ICU) patients. Structured assessment of sedation and agitation is useful to titrate sedative medications and to evaluate agitated behavior, yet existing sedation scales have limitations. We measured inter-rater reliability and validity of a new 10-level (+4 "combative" to -5 "unarousable") scale, the Richmond Agitation-Sedation Scale (RASS), in two phases. In phase 1, we demonstrated excellent (r = 0.956, lower 90% confidence limit = 0.948; kappa = 0.73, 95% confidence interval = 0.71, 0.75) inter-rater reliability among five investigators (two physicians, two nurses, and one pharmacist) in adult ICU patient encounters (n = 192). Robust inter-rater reliability (r = 0.922-0.983) (kappa = 0.64-0.82) was demonstrated for patients from medical, surgical, cardiac surgery, coronary, and neuroscience ICUs, patients with and without mechanical ventilation, and patients with and without sedative medications. In validity testing, RASS correlated highly (r = 0.93) with a visual analog scale anchored by "combative" and "unresponsive," including all patient subgroups (r = 0.84-0.98). In the second phase, after implementation of RASS in our medical ICU, inter-rater reliability between a nurse educator and 27 RASS-trained bedside nurses in 101 patient encounters was high (r = 0.964, lower 90% confidence limit = 0.950; kappa = 0.80, 95% confidence interval = 0.69, 0.90) and very good for all subgroups (r = 0.773-0.970, kappa = 0.66-0.89). Correlations between RASS and the Ramsay sedation scale (r = -0.78) and the Sedation Agitation Scale (r = 0.78) confirmed validity. Our nurses described RASS as logical, easy to administer, and readily recalled. RASS has high reliability and validity in medical and surgical, ventilated and nonventilated, and sedated and nonsedated adult ICU patients.

Assessing sedation with regional anesthesia: inter-rater agreement on a modified Wilson sedation scale

A valid and reliable means for measuring sedation during regional anesthesia would be valuable for both research and practice. Current methods of monitoring sedation include machine-, patient-, and observer-based assessment. The reliability of machine-based methods is limited at lower levels of sedation, whereas patient-based methods are impractical at higher levels. Observer-based methods offer the best alternative for assessing sedation during regional anesthesia; however, their reliability has not been adequately documented. We examined the interrater reliability of the Wilson sedation scale. Sedation was assessed by pairs of anesthesia care providers in 100 patients undergoing surgical procedures with regional anesthesia. On the basis of the findings, the scale was modified, and 50 additional patients were assessed. The study protocol called for a series of standardized stimuli administered by a research assistant. Raters were blinded to each other's ratings. Interrater reliability was assessed by using the kappa statistic, a measure of actual agreement beyond agreement by chance. When continuing checks on its operationalization and reliability are included, the modified Wilson scale provides a simple and reliable means by which to assess and monitor intraoperative sedation.

IMPLICATIONS

We evaluated the interrater reliability of the Wilson scale for measuring sedation during regional anesthesia. Paired anesthesia care providers' ratings of patient sedation indicated very good interrater reliability in both the original scale and a modified version. The modified Wilson scale provides a quick noninvasive means of monitoring sedation during regional anesthesia.