Research article
Use of the CAM-ICU during daily sedation stops in mechanically ventilated patients as assessed and experienced by intensive care nurses – A mixed-methods study

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Abstract

Background

Mechanically ventilated patients are at risk of developing delirium, which increases mortality and prolongs their stay in the Intensive Care Unit (ICU).

Aim

To investigate the assessment of delirium by ICU nurses and their experiences of using the Confusion Assessment Method for Intensive Care Unit (CAM-ICU) in mechanically ventilated patients during daily sedation stops.

Methods

The study employed an explanatory sequential mixed-methods design. The data (n = 30) were collected by two nurses who assessed the same patient (n = 15) using the tool. Data from the nurses’ assessments were analysed by means of frequency analysis, while the interviews were analysed phenomenographically using Dahlgren and Fallberg’s seven categories.

Findings

Four pairs of nurses made similar assessments, three pairs had differing assessments and in eight pairs, one of the nurses did not fill in the form properly. The interviews revealed variations in ICU nurses’ preparation for, views on and use of the CAM-ICU.

Conclusion

Assessment and use of the CAM-ICU revealed variations, indicating the necessity of identifying barriers within the ICU team. ICU nurses need training in the use of the CAM-ICU and support in their decision–making. The individual nurse must take responsibility for updating their knowledge and for following guidelines.

Introduction

Mechanically ventilated patients in Intensive Care Units (ICUs) are at great risk of developing delirium (Hayhurst et al., 2016). Advanced age, multisystem disease and medication are factors that can increase this risk (Zaal et al., 2015). “Triggering factors” can be pain, hypoxia, infections, sleep disturbance and medications (Hayhurst et al., 2016). Studies indicate that delirium leads to higher mortality, a longer time in the ICU and poor outcomes in hospitalised patients (Ely et al., 2001b, Milbrandt et al., 2004, Pandharipande et al., 2005).

Delirium is an acute or fluctuating reversible attention and cognition disorder, or a change in the level of consciousness (Roberts, 2004). There are three manifestations of ICU delirium: hyperactive delirium, characterised by restlessness, psychomotor hyperactivity, hallucinations, aggression and emotionality; hypoactive delirium, in which the patient is apathetic, lethargic, has slow mental and psychomotor responses, as well as depressive features and mixed delirium, where there are elements of both hyper- and hypoactive delirium (Roberts, 2004, Svenningsen and Tonnesen, 2011). A systematic review of delirium in ICUs, surgical departments and emergency departments revealed under-recognition (Neto et al., 2012). Although hypoactive delirium is the most common, it goes unrecognised in more than two thirds of patients (Ely et al., 2004). To date, this kind of delirium has received the least attention (Ely et al., 2001a, Svenningsen and Tonnesen, 2011), because patients can often be misdiagnosed as demented or depressed (Bourne, 2008).

Studies have shown that assessments of delirium are rare and not systematic (Devlin et al., 2008, Ely et al., 2004, Randen and Bjørk, 2010, Zaal et al., 2015), and the frequency has been found to vary from 16% to 89% (Zaal et al., 2015). Eastwood et al. (2012) have found that prescriptions of antipsychotic medications increased significantly in the CAM-ICU period despite no difference in patient profile. This indicates that focus on delirium assessment reveals incidences of delirium. However, using different instruments focusing on delirium one might receive more nuanced responses from patients. According to Bourne (2008), assessment makes it possible to detect delirium at an earlier stage and to identify and treat the triggering factors. Early detection of delirium may improve the treatment outcome for patients (Ely et al., 2004), which can enhance patient safety by preventing the risk of diagnostic error (Stichler, 2016). Treatment can include increased mobility, differentiating between day and night and ensuring quiet surroundings combined with the use of a sedation. Antipsychotic drug therapy is also recommended (Zaal et al., 2013).

Several tools can be used when screening for delirium (Luetz et al., 2010). The National Institute for Health and Clinical Excellence (National Clinical Guideline Centre UK, 2010) has recommended the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), which is supported by several studies (Gusmao-Flores et al., 2012, Han et al., 2014, Neto et al., 2012). The tool has been translated and validated in Norwegian and approved by Ely, who holds the copyright (Ely et al., 2001a). The CAM-ICU has four areas that are designed to reveal delirium: the patient has acute changes in mental status, has fluctuating levels of consciousness or is inattentive, and either has altered levels of consciousness or disoriented thinking (Ely et al., 2001a, Riekerk et al., 2009). During the course of daily sedation stops, the Richmond Agitation Sedation Scale (RASS) is used to assess the patient’s alertness (Ely et al., 2003, Sessler et al., 2002). The RASS score is the basis for assessing whether the patient is sufficiently awake to be evaluated by the CAM-ICU.

Nurses were found to have positive attitudes towards the CAM-ICU both before and after its introduction (Eastwood et al., 2012). The same study revealed that nurses thought that it was worth spending time on the CAM-ICU assessment, although some found the tool difficult to use. Mistarz et al. (2011) described significant discrepancies in the detection of delirium by nurses who only used clinical observations compared to nurses who used the CAM-ICU, leading to the conclusion that clinical observations alone are not reliable for detecting delirium. Despite guidelines, delirium assessment varies widely (Devlin et al., 2008), which could be due to the culture of the organisations involved, i.e., their values, attitudes, beliefs and goals (Alayed et al., 2014).

Studies show that identifying delirium has low priority (Oxenbøll-Collet et al., 2016), the CAM-ICU method is difficult to learn (Jung et al., 2013) and ICU nurses harbour a number of concerns regarding the use of the tool (Zamoscik et al., 2017). However, studies are needed to investigate ICU nurses’ assessment of delirium and educational strategies that highlight the effects of such assessments. The aim of this study is to investigate ICU nurses’ assessment of delirium and their experience of using the CAM-ICU for mechanically ventilated patients in the course of daily sedation stops.

The study employed an explanatory sequential mixed-method design (Fetters et al., 2013) based on the collection and analysis of quantitative data, followed by the collection and analysis of qualitative data, to provide a comprehensive picture of the assessment process.

Completed CAM-ICU forms were collected to investigate ICU nurses’ assessments of delirium. Experiences of using the CAM-ICU were obtained by means of individual phenomenographic interviews.

The aim of phenomenography is to identify, describe and systematise the qualitatively different ways people experience, conceive or understand significant aspects of reality (Marton, 1981) Phenomenography focuses on descriptions of the different ways a phenomenon is understood or conceived to be, which in this study concerned nurses’ experiences of delirium assessment using the CAM-ICU. This is referred to as the ‘second-order perspective’, which differs from the ‘first-order perspective’, where the focus is on what the phenomenon really is (Marton, 1981) The second-order perspective is fundamental in phenomenography as it deals with individuals’ conceptions of how a phenomenon appears to them (Marton and Booth, 2000). The findings are presented as descriptive categories, with similarities and differences in individual conceptions of the phenomenon. All the descriptive categories are placed within vertical and horizontal relationships in an outcome space (Barnard et al., 1999).

The study was conducted in an ICU at a hospital in the eastern part of Norway. The ICU has 69 nurses and an average of two mechanically ventilated patients per day. Daily sedation stops were introduced as part of the department’s aim to improve patient safety when reducing the use of ventilators. In this regard a protocol containing the Behaviour Pain Scale (BPS), Richmond Agitation and Sedation Score (RASS) and the CAM-ICU was developed. The implementation of the protocol began in February 2012 and the CAM-ICU was introduced in Spring 2013. The project was led by a group of three ICU nurses.

All ICU nurses received information about the reason for sedation stops from a physician and trained in using the screening tools in the project protocol by a project group of specialist nurses. The CAM-ICU was one of these tools. The project group followed up the ICU nurses by offering individual instruction in the use of the CAM-ICU, reminding them to carry out assessments and collecting feedback on completed assessments.

Thirty ICU nurses from the same department took part by assessing ventilated patients using the CAM-ICU. Of these, seven were interviewed individually about their experience of using the CAM-ICU. Purposive sampling was employed to achieve variation in age, gender, education, experience of intensive care and experience of using the CAM-ICU. The intention was to achieve width in the data, in line with the recommendations pertaining to phenomenography (Sjöström and Dahlgren, 2002) (Table 1).

Participants who made assessments using the CAM-ICU: Nursing experience ranged from seven to 38 years, with a mean of 19.6 years. Intensive care nursing experience ranged from six months to 21 years, with a mean of 7.9 years.

Participants interviewed: Nursing experience ranged from seven to 38 years, with a mean of 19.8 years. Intensive care nursing experience ranged from six months to 21 years, with a mean of 7.3 years.

Data were collected from completed CAM-ICU forms and through qualitative interviews about three months after implementation of the use of the CAM-ICU.

Two pairs of nurses mapped delirium in the same fifteen ventilated patients using the CAM-ICU immediately after one another. The completed forms were numbered by the bedside nurse leader and handed to the researcher when all the assessments were completed.

Individual interviews were conducted to expand on the ICU nurses’ perceptions of using the CAM-ICU. In phenomenographic interviews, it is important to establish a common understanding of the phenomenon (Ashworth and Lucas, 1998) This was achieved by ensuring that all participants had been trained in advance and had conducted assessments using the CAM-ICU. Each interview started by referring to the assessments and asking the following question: ‘Can you please describe what the CAM-ICU is?’

The participants were then asked to share their experiences of using the CAM-ICU. The interviews followed a semi-structured guide containing questions about perceptions of using the CAM-ICU. The participants were also asked to provide examples that were followed-up by probing questions such as ‘Can you please tell me more about…’

The interviews, which took place in the 14-day period following the assessments, were held during the participants’ working hours and lasted approximately one hour. All interviews were digitally recorded, conducted and transcribed.

Participation was based on informed consent, confidentiality and voluntariness and the participants were informed that they could withdraw from the study at any time without consequences. The participants received written and oral information about the aim of the study, which adhered to the ethical guidelines for research set out in the Helsinki Declaration. The Norwegian Centre for Research Data was notified about the study (NSD 32018), which was approved by the Hospital’s Privacy policy for research (2012/17881).

A manual frequency analysis was performed on the data. Data from the interviews were analysed in accordance with Dahlgren and Fallberg’s (1991) seven categories.

In the first phase, familiarisation, all interviews were read through repeatedly in order to become familiar with the material. A summary of each interview was written, after which all the interviews were summarised in the condensation phase to create an overall impression of the material.

The next phase, comparison, involved systematic work to reveal similarities and differences. The aim was to understand the meaning of the individual statements while identifying the coherent patterns and descriptions reflected in the statements. This process was repeated several times. The material was then divided into areas in the grouping phase, followed by a search for parts that could describe the overall experience. In the articulating phase the responses were grouped, followed by work to categorise and name the statements on a collective level in the labelling phase. In the final phase, contrasting, underlying structures were analysed to arrive at the outcome sphere. The analysis process was repeated several times by all three authors.

Section snippets

Assessments of delirium

The assessments of delirium differed in terms of the completion of the forms and the results as shown in Table 2.

Four pairs of nurses made a similar assessment of the patient. Of these, one pair assessed the patient as delirious, two pairs assessed the patient as not delirious, while one pair reported that it was not possible to assess the patient. Three pairs arrived at different conclusions, i.e., one nurse assessed the patient as delirious, while the other was of the opposite opinion. Out of

Discussion

The aim of the study was to gain knowledge of how ICU nurses assess for delirium in mechanically ventilated patients and to understand their perceptions of using the CAM-ICU as an assessment tool.

The completed CAM-ICU forms showed differences both in how the pairs of nurses had filled them in and in the results of the assessments of the same patient. This suggests that the form and guidelines are not sufficient for ensuring that delirium is correctly diagnosed in patients. Other studies also

Limitations

The CAM-ICU assessment sample is small, as only 30 ICU nurses participated in the study. While it gives an insight into how they conduct assessments, the sample is too small to generalise the findings. Nevertheless, it indicates that guidelines are not enough for diagnosing delirium and highlights the need for further studies. Two ICU nurses completed assessments using the CAM-ICU on the same patient consecutively, which may have had an influence on the patient’s concentration. For the

Conclusion

The ICU nurses’ assessment and use of the CAM-ICU tool showed variations. This could indicate that one should identify barriers within teams working together, as motivation and influence within the team appear to be critical for successful implementation of the CAM-ICU. In addition, training in the use of nursing tools should be considered as extra support for nurses’ decision-making. Furthermore, each individual nurse must take responsibility for updating her/his knowledge and for following

Source of funding

The study is funded by Inland Norway University of Applied Sciences.

Conflict of interest

The authors declare that there is no conflict of interest.

Acknowledgments

The authors wish to thank the 30 ICU nurses who participated in the study by assessing delirium in patients using the CAM-ICU, as well as the seven nurses who took part in the interviews and shared their experiences of using the CAM-ICU. We also wish to express our gratitude to the project group, ICU managers and the medical supervisor who made it possible to conduct the study. Thanks to Monique Federsel for reviewing the English language.

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