Review objective

The objective of this systematic review is to synthesize the best available evidence regarding nurses' perceptions of confidence using the Pasero Opioid-Induced Sedation Scale (POSS) to assess unintended patient sedation in hospital settings.

Background

Opioid analgesics are the most commonly used treatment modality for the management of pain in hospitalized patients.1 The administration of opioid analgesics is associated with several adverse side effects. The most significant of these is life-threatening respiratory depression,2 which has been noted to be preceded by increased sedation.3,4 Respiratory depression is defined as decreased effectiveness of ventilatory function.1 In comparison, sedation is defined as a medication-related depression of brain activity exhibited by decreased wakefulness, fatigue and performance impairment.5 Opioid-induced sedation is found on a continuum from fully conscious to a complete loss of consciousness and respiratory arrest.4 Opioid agonist analgesics, such as morphine and fentanyl, bind with opioid receptors in the central nervous system (CNS) and reduce the rate of neuronal firing in the brain, resulting in a decline in arousal, decreased cognitive processing,6 and the potential for unintended sedation. The level of sedation associated with opioid administration has great individual variation and is based on many factors, including the drug dosage and route, as well as the patient's drug tolerance and current medical condition.1

In the hospitalized surgical patient, the prior administration of anesthetic agents may amplify unintended sedation. For the purposes of this review, hospital settings are defined as nursing units caring for the adult medical-surgical adult patient as well as post-anesthesia care units (PACU) or nursing areas that care for the immediate post-surgical adult patient who is recovering from anesthesia. Cognitive and motor processing remains intact in hospitalized patients who are sedated, but the processing is affected by reduced CNS activity by the action of the opioids.7 Central nervous system sedation frequently is apparent prior to respiratory depression and is reported as one of the most commonly occurring side effects of opioids.8

In addition to patient safety aspects of unintended sedation, there are financial implications as well. Opioid-related adverse effects significantly increase inpatient hospital costs related to increased length of stay.10 In a large prospective analysis conducted in the United Kingdom, opioids were identified as the most commonly prescribed drugs associated with adverse drug reactions leading to an increased hospital length of stay.8 According to the Joint Commission, 25% of patient events resulting in permanent loss of function or death between 2005 and 2010 were opioid-related, and improper monitoring was present in 58% of these events.9 There is a common incidence of increased sedation in hospitalized patients who are opioid naive (not previously taking regular daily opioid doses) with the initiation of opioid therapy or in any patient with any significant increase in opioid dose.11 Pain stimulates ventilation through the activation of the autonomic nervous system. When patients achieve pain control after experiencing poor pain control, they too, are at increased risk for respiratory depression.12

Adverse events, including patient death from excessive sedation and respiratory depression, have led to assessment and monitoring practice change recommendations for the safe care of the patient receiving opioid therapy in the hospital setting.9 Safe care of the patient receiving opioid therapy can be categorized into two main components: assessment and intervention. To adequately intervene, clinicians need appropriate and easy to use assessment tools. The foundation and gold standard for assessing and reporting patient pain is to use the patient's own self-report.4 Unfortunately, there is no real analog to self-report for sedation, as patients who are sedated would have challenges being able to self-report. As such, it is incumbent upon nurses and other front line clinicians to have the assessment tools and skills to conduct effective sedation assessments. Although there is a broad literature base and a number of tools in use for the monitoring of intentional goal-directed sedation in critical care areas (e.g. Richmond Agitation and Sedation Scale [RASS]), there is a paucity of literature that has examined assessment tools and nurse monitoring for unintended sedation in the hospital setting. Intentional goal-directed sedation is defined as planned and desired sedation of patients for diagnostic or therapeutic purposes.13 Conversely, unintended sedation is defined as sedation that is an unplanned or unwanted consequence related to medication side effects. Despite the limited literature, the Joint Commission and the American Society for Pain Management Nursing have recommended the Pasero Opioid-Induced Sedation Scale (POSS) as one of the scales hospital-based clinicians can use to prevent adverse events associated with opioid administration.14

While the POSS is in widespread use in hospital settings and has reported strong reliability with a Cronbach alpha of 0.903,3 the extant literature is limited at the time of this review to nurse perceptions surrounding the use of the POSS. Nurse perception is defined as nurses' self-report of their feelings, judgments and/or attitudes. This review focuses on nurse perceptions of the POSS in assessing unintended patient sedation in hospital settings. For the purposes of this review, nurse perceptions will be limited to nurses' perceptions of confidence using the POSS assessment tool.

The work of this review will allow for the development of empirically-based policies and procedures that address the assessment of unintended sedation and the identification of patients at high risk for this condition. This review will also provide direction for health care team education and training related to the assessment of unintended sedation in the hospitalized patient population during opioid pain management.

A comprehensive search in PubMed and CINAHL found primary studies that explored the nurses' perceptions and experiences of using the POSS tool.3,14 A search was also completed for existing systematic reviews on nurse perceptions with the use of the POSS scale in PubMed, CINAHL, EMBASE, PsycINFO, Cochrane Library, and JBI Database of Systematic Review and Implementation Reports. No systematic reviews on this topic were found.

Inclusion criteria

Types of participants

This review will consider studies that included nurses who work in hospital settings and who use the POSS tool to assess adult patients for unintended sedation. Unintended sedation is defined as sedation that is an unplanned or unwanted consequence related to medication side effects. For the purposes of this review, hospital settings are defined as nursing units caring for the adult medical-surgical patient as well as nursing areas that care for the immediate post-surgical patient who is recovering from anesthesia (Post Anesthesia Care Unit [PACU]).

Types of intervention(s)

This review considered descriptive epidemiological study designs including case series, individual case reports, descriptive cross sectional studies, and descriptive studies that examined nurse perceptions of the POSS tool.

Types of outcomes

This review considered studies that included the following outcome measure: nurses' perception of confidence using the POSS assessment tool.

Search strategy

The search strategy aims to find both published and unpublished studies in the English language. The timeframe for studies will be those published or in press between 1994 and 2014. The POSS was developed by Chris Pasero in 1994 to detect and prevent clinically significant opioid-induced unwanted sedation.13 A three-step search strategy will be utilized in review. An initial limited search of PubMed and CINAHL will be undertaken followed by analysis of the text words contained in the title and abstract, and of the index terms used to describe the article. A second search using all identified keywords and index terms will then be undertaken across all included databases. Thirdly, the reference list of all identified reports and articles will be searched for additional studies.

The databases to be searched include:

PubMed

EMBASE

CINAHL

PsycINFO

The search for unpublished studies will include:

Google Scholar

ProQuest (dissertations and theses)

The initial keywords to be used will be: unwanted sedation; Pasero Opioid-Induced Sedation Scale (POSS); nurses; perceptions; hospital; post-surgical, opioid-induced sedation; postoperative; post-surgical; post anesthesia.

Assessment of methodological quality

Quantitative papers selected for retrieval will be assessed by two independent reviewers for methodological validity prior to inclusion in the review using standardized critical appraisal instruments from the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI) (Appendix I). Any disagreements that arise between the reviewers will be resolved through discussion, or with a third reviewer.

Data extraction

Quantitative data will be extracted from papers included in the review using a modified data extraction tool using Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI) (Appendix II).

Data synthesis

Narrative synthesis of quantitative data will be provided using tables and figures to aid in presentation where appropriate.

Conflicts of interest

The authors have no conflict of interest to declare.

Acknowledgements

American Society of PeriAnesthesia Nurses (ASPAN).

References