Delirium in the intensive care unit

The Effect of Noise in the Intensive Care Unit on the Oxidative Stress Response in Rats

OBJECTIVE

The objective of this study was to determine the effect of noise in the intensive care unit (ICU) on oxidative stress in a rat model.

METHOD

This study had both a descriptive and a randomized controlled experimental stage. In the descriptive stage, to create a laboratory model of noise in the ICU, the noise level was measured for 24 hr on a randomly selected day in a surgical ICU, and voice recording was performed using a sound recording device. In the experimental stage, 30 male Wistar albino rats were randomly divided into 5 groups: a control group and groups exposed to the recording of the noise from the ICU for 24, 48, 72, and 168 hr.

RESULTS

The noise level in the ICU was higher than the levels recommended for hospitals. Plasma corticosterone levels of the rats in the group exposed to the ICU noise for 168 hr were significantly higher than those of the control group. Plasma total protein values were significantly reduced in the rats exposed to 48, 72, and 168 hr of ICU noise compared to those of the control group. Superoxide dismutase activity was significantly decreased and malondialdehyde levels significantly increased in serum, spleen, and brain tissues as the duration of noise exposure increased.

CONCLUSION

Findings reveal that rats experienced increasing levels of stress and oxidative stress as time exposed to the ICU noise increased. These results suggest that interventions to reduce noise in the ICU may be warranted.

Dexmedetomidine Attenuates Lipopolysaccharide Induced MCP-1 Expression in Primary Astrocyte

Background. Neuroinflammation which presents as a possible mechanism of delirium is associated with MCP-1, an important proinflammatory factor which is expressed on astrocytes. It is known that dexmedetomidine (DEX) possesses potent anti-inflammatory properties. This study aimed to investigate the potential effects of DEX on the production of MCP-1 in lipopolysaccharide-stimulated astrocytes. Materials and Methods. Astrocytes were treated with LPS (10 ng/ml, 50 ng/ml, 100 ng/ml, and 1000 ng/ml), DEX (500 ng/mL), LPS (100 ng/ml), and DEX (10, 100, and 500 ng/mL) for a duration of three hours; expression levels of MCP-1 were measured by real-time PCR. The double immunofluorescence staining protocol was utilized to determine the expression of α2-adrenoceptors (α2AR) and glial fibrillary acidic protein (GFAP) on astrocytes. Results. Expressions of MCP-1 mRNA in astrocytes were induced dose-dependently by LPS. Administration of DEX significantly inhibited the expression of MCP-1 mRNA (P < 0.001). Double immunofluorescence assay showed that α2AR colocalize with GFAP, which indicates the expression of α2-adrenoceptors in astrocytes. Conclusions. DEX is a potent suppressor of MCP-1 in astrocytes induced with lipopolysaccharide through α₂A-adrenergic receptors, which potentially explains its beneficial effects in the treatment of delirium by attenuating neuroinflammation.

Risk Factors for Acute Delirium in Critically Ill Adult Patients: A Systematic Review

Background. Delirium is characterized by disturbances of consciousness, attention, cognition, and perception. Delirium is a serious but reversible condition associated with poor clinical outcomes. This has implications for the critically ill patient; the effects of delirium cause long term sequelae, principally cognitive deficits, and functional decline. Objectives. The objective of the paper was to describe risk factors associated with delirium in critically ill adult patients. Methods. Published and unpublished literature from 1990 to 2012, limited to English, was searched using ten databases. Results. Twenty-two studies were included in this paper. A large number of risk factors were presented in the literature; some of these were common across all settings whilst others were exclusive to the type of setting. Benzodiazepines and opioids were shown to be risk factors for delirium independent of setting. Conclusion. With regard to patients admitted to medical and surgical intensive care units, risk factors of older age and comorbidity were common. In the cardiac ICU, older age and lower Mini-Mental Status Examination scores were cited most often as risk factors for delirium, but other risk factors exclusive to the setting were also significant. Benzodiazepines were identified as the most significant pharmacological risk factor for delirium.

Delirium: a review of the nurses role in the intensive care unit

AIM

This article aims to review current literature into the use of assessment tools for the diagnosis of delirium and the implications of care for the patient with delirium.

BACKGROUND

Delirium is a common often misdiagnosed, unrecognised and misunderstood condition in the critical care setting that has been associated with increased mortality and cognitive dysfunction.

RELEVANCE TO CLINICAL PRACTICE

Delirium has implications for increasing cost to the National Health Service as it is linked to prolonged ventilation and the associated risks and increased hospital stay.

CONCLUSION

Nurses play a key role in identification of delirium using CAM-ICU, a valid and reliable tool and identifying modifiable risks to improve the delirious ICU patient's outcome.

Delirium--awareness, observation and interventions in intensive care units: a national survey of Swedish ICU head nurses

OBJECTIVES

To survey the awareness and observation of delirium, and interventions used for delirium in Swedish intensive care units (ICUs) and to examine the influence of hospital categories and staff education on the afore-mentioned.

DESIGN

A questionnaire was sent to all Swedish adult patient ICUs (n=82) and completed by 55 units.

RESULTS

The reported prevalence of delirium was 9.4%. Assessment of delirium was performed by 62% of the ICUs, commonly by observing symptoms. Most of the suggested non-pharmacologic interventions were reported to be used by at least 85% of the units. Drugs were used by 96%, most commonly haloperidol, propofol and benzodiazepines. Written pharmacological guidelines existed in 26% of the units, while 9% had non-pharmacological guidelines. Regular observation of delirium was more common in larger hospitals than in smaller ones and education was associated with reporting a higher prevalence of delirium.

CONCLUSION

As in other countries, this study demonstrated that the awareness of delirium in ICUs is low with a lack of implementation of validated screening tools for its diagnosis. Emphasis should be placed on education and implementation of these tools to improve the quality of care for ICU patients.

Teaching staff nurses the CAM-ICU for delirium screening

The confusion assessment method for the intensive care unit (CAM-ICU) is a tool for screening for delirium in ventilated patients that with proper training can be administered quickly by staff nurses in the ICU. Unrecognized delirium can have a range of negative consequences, and in the elderly patients, it may be the first sign of an acute illness that, if left untreated, could result in death. Appropriate and early recognition is therefore imperative. Training staff to use the CAM-ICU requires not only a basic understanding of delirium and a firm orientation to the tool's features but also some preparatory decisions about tool usage and a defined approach to integrate the tool into the physical assessment process. Preparatory decisions include (1) how the tool will be used, (2) defining the process for identifying and recording baseline mental status, and (3) defining how documentation will occur. On the basis of the experience of teaching this tool to staff nurses, a 6-step process is explicated to facilitate integration: (1) putting it in context, (2) defining the features, (3) talking about tough cases, (4) doing the assessment, (5) documenting the assessment, and (6) continuing to discuss.

Multicentre study of delirium in ICU patients using a simple screening tool

Traditionally, intensive care unit (ICU) delirium was viewed as benign and was under-diagnosed in the absence of ICU-appropriate screening tools. Research suggests that up to half of all ICU patients experiencing delirium will continue to do so after discharge to the ward, and half of those experiencing delirium in the ward will die within 1 year of delirium diagnosis. ICU-specific screening tools are now available. The purpose of this study was to identify the incidence of delirium in ICU and explore its associations to clinical factors and outcomes. A secondary aim was to evaluate the usefulness of the intensive care delirium screening checklist (ICDSC). A total of 185 patients in six ICUs in Australia and New Zealand were screened for delirium using the ICDSC over two 12-hour periods per day for the duration of their ICU admission. Some 84 patients (45%) developed delirium. Development of delirium was associated with increased severity of illness (acute physiology and chronic health evaluation--APACHE II--and sequential organ failure assessment--SOFA), ICU length of stay (LOS), and use of psycho-active drugs. Delirious patients showed no statistically significant difference in ICU and hospital mortality rates, nor prolonged hospital LOS. The ICDSC was found to be user-friendly. The incidence of delirium, observed characteristics and outcomes for patients admitted to Australian and New Zealand ICUs for > 36 hours without any history of altered mental state fell in the mid-range and were generally consistent with previous literature. An ICU-specific delirium assessment, such as the ICDSC, should be included in routine ICU observations to minimise under-diagnosis of this serious phenomenon.

Factual memories of ICU: recall at two years post-discharge and comparison with delirium status during ICU admission - a multicentre cohort study

AIMS AND OBJECTIVE

To examine the relationship between observed delirium in ICU and patients' recall of factual events up to two years after discharge.

BACKGROUND

People, the environment, and procedures are frequently cited memories of actual events encountered in ICU. These are often perceived as stressors to the patients and the presence of several such stressors has been associated with the development of reduced health-related quality of life or post-traumatic stress syndrome.

DESIGN

Prospective cohort study using interview technique.

METHOD

The cohort was assembled from 152 patients who participated in a previously conducted multi-centre study of delirium incidence in Australian ICUs. The interviews involved a mixture of closed- and open-ended questions. Qualitative responses regarding factual memories were analysed using thematic analysis. A five-point Likert scale with answers from 'always' to 'never' was used to ask about current experiences of dream, anxiety, sleep problems, fears, irritability and/or mood swings. Scoring ranged from 6 to 30 with a mid-point value of 18 indicating a threshold value for the diagnosis of post-traumatic stress syndrome. A P-value of <0.05 was considered significant for all analyses.

RESULTS

Forty-one (40%) out of 103 potential participants consented to take part in the follow-up interview; 18 patients (44%) had been delirious and 23 patients (56%) non-delirious during the ICU admission. The non-participants (n = 62) formed a control group to ensure a representative sample; 83% (n = 34) reported factual memories either with or without recall of dreaming. Factual memories were significantly less common (66% cf. 96%) in delirious patients (OR 0.09, 95%CI 0.01-0.85, p = 0.035). Five topics emerged from the thematic analysis: 'procedures', 'staff', 'comfort', 'visitors', and 'events'. Based on the current experiences, five patients (12%, four non-delirious and one delirious) scored > or =18 indicative of symptoms of post-traumatic stress syndrome; this did not reach statistical significance. Memory of transfer out of ICU was less frequent among the delirious patients (56%, n = 10) than among the non-delirious patients (87%, n = 20) (p = 0.036).

CONCLUSION

Most patients have factual memories of their ICU stay. However, delirious patients had significantly less factual recall than non-delirious patients. Adverse psychological sequelae expressed as post-traumatic stress syndrome was uncommon in our study. Every attempt must be made to ensure that the ICU environment is as hospitable as possible to decrease the stress of critical illness. Post-ICU follow-up should include filling in the 'missing gaps', particularly for delirious patients. Ongoing explanations and a caring environment may assist the patient in making a complete recovery both physically and mentally.

RELEVANCE TO CLINICAL PRACTICE

This study highlights the need for continued patient information, re-assurance and optimized comfort. While health care professionals cannot remove the stressors of the ICU treatments, we must minimize the impact of the stay. It must be remembered that most patients are aware of their surroundings while they are in the ICU and it should, therefore, be part of ICU education to include issues regarding all aspects of patient care in this particularly vulnerable subset of patients to optimize their feelings of security, comfort and self-respect.

Noise levels in a general intensive care unit: a descriptive study

The aim of this small-scale study was to measure, analyse and compare levels of acoustic noise, in a nine-bedded general intensive care unit (ICU). Measurements were undertaken using the Norsonic 116 sound level meter recording noise levels in the internationally agreed 'A' weighted scale. Noise level data were obtained and recorded at 5 min over 3 consecutive days. Results of noise level analysis indicated that mean noise levels within this clinical area was 56.42 dB(A), with acute spikes reaching 80 dB(A). The quietest noise level attained was that of 50 dB(A) during sporadic intervals throughout the 24-h period. Parametric testing using analysis of variance found a positive relationship (p <or= 0.001) between the nursing shifts and the day of the week. However, Scheffe multiple range testing showed significant differences between the morning shift, and the afternoon and night shifts combined (p <or= 0.05). There was no statistical difference between the afternoon and night shifts (p >or= 0.05). While the results of this study may seem self-evident in many respects, what it has highlighted is that the problem of excessive noise exposure within the ICU continues to go unabated. More concerning is that the prolonged effects of excessive noise exposure on patients and staff alike can have deleterious effect on the health and well-being of these individuals.

Part 1. Chemical and physical restraints in the management of mechanically ventilated patients in the ICU: contributing factors

Chemical and physical restraints are frequently used in the intensive care unit (ICU) to control agitated patients and to prevent self-harm and unplanned extubations. Published work relating to the numerous issues of the care and treatment strategies for these patients remains conflicting and unclear. Literature regarding sedation and chemical restraint reveals a trend towards management with lighter sedation, use of sedation assessment tools and sedation protocols. It remains unclear which treatment is best for agitated and delirious patients, and the evidence on the effect of sedation is conflicting. A large portion of the literature on the use of physical restraint is from general hospital wards and residential homes, and not from the ICU environment. The purpose of this paper is to provide a summary of the existing literature on the use of physical and chemical restraints in the ICU setting. In Part 1 of this two-part paper, the evidence on chemical and physical restraints is explored with specific focus on definition of terms, unplanned extubation, agitation, delirium and the impact of nurse-patient ratios in the ICU on these issues. Part 2 of the paper examines the evidence related to chemical and physical restraints from the perspective of the mechanically ventilated patient.

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.

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.

British Association of Critical Care Nurses position statement on the use of restraint in adult critical care units

Critical care nurses in the United Kingdom have become increasingly concerned about the use, potential abuse and risks associated with physical restraint of patients. Restraint in critical care is not only confined to physical restraint but can also encompass chemical and psychological methods. There are concerns regarding the legal and ethical issues relating to the (ab)use of physical restraint techniques in critical care. The aim of this article was to present the British Association of Critical Care Nurses (BACCN) position statement on the use of restraint in adult critical care units and to provide supporting evidence to assist clinical staff in managing this process.