Delirium in the ICU : a review

AIM The aim of this paper was to review the current discourse in relation to intensive care unit (ICU) delirium. In particular, it will discuss the predisposing and contributory factors associated with delirium's development as well as effects of delirium on patients, staff and family members. BACKGROUND Critically ill patients are at greater risk of developing delirium and, with an ageing population and increased patient acuity permitted by medical advances, delirium is a growing problem in the ICU. However, there is a universal consensus that the definition of ICU delirium needs improvement to aid its recognition and to ensure both hypoalert-hypoactive and hyperalert-hyperactive variants are easily and readily identified. RELEVANCE TO CLINICAL PRACTICE The effects of ICU delirium have cost implications to the National Health Service in terms of prolonged ventilation and length of hospital stay. The causes of delirium can be readily classified as either predisposing or precipitating factors, which are organic in nature and commonly reversible. However, contributory factors also exist to exacerbate delirium and having an awareness of all these factors promises to aid prevention and expedite treatment. This will avoid or limit the host of adverse physiological and psychological consequences that delirium can provoke and directly enhance both patient and staff safety. CONCLUSIONS Routine screening of all patients in the ICU for the presence of delirium is crucial to its successful management. Nurses are on the front line to detect, manage and even prevent delirium.

Advancing practice in critical care : a model of knowledge integration

Aim The aim of this paper was to discuss the potential development of a conceptual model of knowledge integration pertinent to critical care nursing practice. A review of the literature identified that reflective practice appeared to be at the forefront of professional development. Background It could be argued that advancing practice in critical care has been superseded by the advanced practice agenda. Some would suggest that advancing practice is focused on the core attributes of an individual’s practice, which then leads onto advanced practice status. However, advancing practice is more of a process than identifiable skills and as such is often negated when viewing the development of practitioners to the advanced practice level. For example, practice development initiatives can be seen as advancing practice for the masses, which ensures that practitioners are following the same level and practice of care. The question here is, are they developing individually? Relevance to clinical practice What this paper presents is that reflection may not be best suited to advancing practice if the individual practitioner does not have a sound knowledge base both theoretically and experientially. The knowledge integration model presented in this study uses multiple learning strategies that are focused in practice to develop practice, e.g. the use of work-based learning and clinical supervision. To demonstrate the models application, an exemplar of an issue from practice shows its relevance from a practical perspective. Conclusions In conclusion, further knowledge acquisition and its relationship with previously held theory and experience will enable individual practitioners to advance their own practice as well as being a resource for others.

The consultative process used in outreach : a narrative account

Aim The aim of this paper was to provide a narrative account of the communication skills used in an effective outreach consultation utilizing Neighbour’s consultative model. Other consultation models were considered; however, because of their overly comprehensive approach or emphasis on behaviour modification, these were deemed inappropriate. Background The nursing profession has endured significant changes of late and as a result is developing more autonomous roles in both the community and the acute health care settings. In the past, the term consultancy was used within the medical context; nowadays, there are advance nurse practitioners for whom consultancy is an integral part of their role. Although every nursing interaction is in essence a consultation, the fact that nurses are taking up on new advanced roles highlights the necessity for nurses to develop their consultation skills even further. Therefore, it makes sense to explore what aspects of that consultancy role needs special consideration in order to ensure that positive outcomes are achieved. Conclusions This paper has used a narrative account to uncover those salient skills needed to enhance the therapeutic relationship with a patient requiring the services of outreach. Furthermore, the application of a recognized consultation model was used to elucidate the underpinning knowledge of systematic history taking and assessment as well as demonstrating the communication skills and strategies needed to increase the patient’s participation and empowerment throughout the consultation. Relevance to clinical practice Effective communication skills encompassed in a consultative model are integral to the success in safeguarding the well-being of patients requiring advanced levels of care. Prejudging or pre-empting information being conveyed can be detrimental to patient safety and may prolong or complicate treatment plans.

A dedicated retrieval and transfer service : the QUARTS project

Background The transfer and/or retrieval of a critically patient is inherently dangerous not only for the patient but for staff as well. The quality and experience of unplanned transfers can influence patient mortality and morbidity. However, international evidence suggests that dedicated transfer/retrieval teams can improve mortality and morbidity outcomes. Aims The initial aim of this paper is to describe an in-house competency-based training programme, which encompasses the STaR approach to develop members of our existing nursing team to be part of the dedicated transfer/retrieval service. The paper also presents audit data findings which examined the source of referrals, number of patients actually transferred and clinical status of those being transferred. Results Audit data illustrate that the most frequent source of referrals comes from Accident and Emergency and the Surgical Directorate with the most common presenting condition being cardio-respiratory failure or arrest. Audit data reveal that the number of patients actually transferred or retrieved is relatively small (33%) compared with the overall number of requests for assistance. However, 36% of those patients transferred had a level 2 or level 3 acuity status that necessitated the admission to a critical care area. Conclusions A number of studies have concluded that the ill-experienced and ill-equipped transfer team can place patients’ at serious risk of harm. Whether planned or unplanned, dedicated critical care transfer/retrieval teams have been shown to reduce patient mortality and morbidity.

Sedation breaks : are they good for the critically ill patient? A review.

Background:  Tradition has led us to believe that a heavily sedated patient is a comfortable, settled, compliant patient for whom sedation will improve outcome. The current move witnessed in clinical practice today of limiting sedation has led health care in recent years to question the benefit and necessity of routine, continuous sedation for all patients requiring mechanical ventilation. However, as a result there has been a rise in the amount of agitation being reported as being experienced by patients with the daily withdrawal of sedation. Aims:  The purpose of this paper is to review current arguments for and against perserving with agitation versus re-sedating, when it presents during the daily sedation breaks. Findings:  Of the literature reviewed, the question to re-sedate the mechanically ventilated agitated patient during sedation breaks remains an issue of contention. Although there is evidence focusing on the psychological effects of long-term sedation and sedation breaks specifically, the complex nature of critical illness in some cases means that individualized care is of paramount importance and in-depth assessment is crucial when deciding to re-sedate in the face of undetermined agitation. Agitation has been closely linked with several incidents that can be detrimental to patient safety, such as removal of lines and unplanned self-extubation. Conclusion:  The recommendations of this review are that nurses should re-commence sedation if the patient becomes agitated following a sedation break. Aims:  The purpose of this paper is to review current arguments for and against perserving with agitation versus re-sedating, when it presents during the daily sedation breaks. Findings:  Of the literature reviewed, the question to re-sedate the mechanically ventilated agitated patient during sedation breaks remains an issue of contention. Although there is evidence focusing on the psychological effects of long-term sedation and sedation breaks specifically, the complex nature of critical illness in some cases means that individualized care is of paramount importance and in-depth assessment is crucial when deciding to re-sedate in the face of undetermined agitation. Agitation has been closely linked with several incidents that can be detrimental to patient safety, such as removal of lines and unplanned self-extubation. Conclusion:  The recommendations of this review are that nurses should re-commence sedation if the patient becomes agitated following a sedation break.

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 ≤ 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 ≤ 0·05). There was no statistical difference between the afternoon and night shifts (p ≥ 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.

Bayesian P-splines with a multiplicative term in EMG trace data

A method is proposed to describe force or compound muscle action potential (CMAP) trace data collected in an electromyography study for motor unit number estimation (MUNE). Experimental data was collected using incre- mental stimulation at multiple durations. However, stimulus information, vital for alternate MUNE methods, is not comparable for multiple duration data and therefore previous methods of MUNE (Ridall et al., 2006, 2007) cannot be used with any reliability. Hypothesised ring combinations of motor units are mod- elled using a multiplicative factor and Bayesian P-spline formulation. The model describes the process for force and CMAP in a meaningful way.

Energy-based positioning control of underactuated vehicles using manifold regulation

In this paper, we consider the problem of position regulation of a class of underactuated rigid-body vehicles that operate within a gravitational field and have fully-actuated attitude. The control objective is to regulate the vehicle position to a manifold of dimension equal to the underactuation degree. We address the problem using Port-Hamiltonian theory, and reduce the associated matching PDEs to a set of algebraic equations using a kinematic identity. The resulting method for control design is constructive. The point within the manifold to which the position is regulated is determined by the action of the potential field and the geometry of the manifold. We illustrate the performance of the controller for an unmanned aerial vehicle with underactuation degree two-a quadrotor helicopter.

Molecular and structural basis of androgen receptor responses to dihydrotestosterone, medroxyprogesterone acetate and Δ4-tibolone

Medroxyprogesterone acetate (MPA) has widely been used in hormone replacement therapy (HRT), and is associated with an increased risk of breast cancer, possibly due to disruption of androgen receptor (AR) signaling. In contrast, the synthetic HRT Tibolone does not increase breast density, and is rapidly metabolized to estrogenic 3α-OH-tibolone and 3β-OH-tibolone, and a delta-4 isomer (Δ4-TIB) that has both androgenic and progestagenic properties. Here, we show that 5α-dihydrotestosterone (DHT) and Δ4-TIB, but not MPA, stabilize AR protein levels, initiate specific AR intramolecular interactions critical for AR transcriptional regulation, and increase proliferation of AR positive MDA-MB-453 breast cancer cells. Structural modeling and molecular dynamic simulation indicate that Δ4-TIB induces a more stable AR structure than does DHT, and MPA a less stable one. Microarray expression analyses confirms that the molecular actions of Δ4-TIB more closely resembles DHT in breast cancer cells than either ligand does to MPA.

On evaluation of robust autonomy for uninhabited vehicles and systems

This paper discusses a method to quantify robust autonomy of Uninhabited Vehicles and Systems (UVS) in aerospace, marine, or land applications. Based on mission-vehicle specific performance criteria, we define an system utility function that can be evaluated using simulation scenarios for an envelope of environmental conditions. The results of these evaluations are used to compute a figure of merit or measure for operational efectiveness (MOE). The procedure is then augmented to consider faults and the performance of mechanisms to handle these faulty operational modes. This leads to a measure of robust autonomy (MRA). The objective of the proposed figures of merit is to assist in decision making about vehicle performance and reliability at both vehicle development stage (using simulation models) and at certification stage (using hardware-in-the-loop testing). Performance indices based on dynamic and geometric tasks associated with vehicle manoeuvring problems are proposed, and an example of a two- dimensional y scenario is provided to illustrate the use of the proposed figures of merit.

Parameter estimation of thrust models of uninhabited airborne systems

This paper presents a method for the estimation of thrust model parameters of uninhabited airborne systems using specific flight tests. Particular tests are proposed to simplify the estimation. The proposed estimation method is based on three steps. The first step uses a regression model in which the thrust is assumed constant. This allows us to obtain biased initial estimates of the aerodynamic coeficients of the surge model. In the second step, a robust nonlinear state estimator is implemented using the initial parameter estimates, and the model is augmented by considering the thrust as random walk. In the third step, the estimate of the thrust obtained by the observer is used to fit a polynomial model in terms of the propeller advanced ratio. We consider a numerical example based on Monte-Carlo simulations to quantify the sampling properties of the proposed estimator given realistic flight conditions.

Physical activity and physical fitness in African-American girls with and without obesity

Lack of physical activity and low levels of physical fitness are thought to be contributing factors to the high prevalence of obesity in African-American girls, To examine this hypothesis, we compared habitual physical activity and physical fitness in 54 African-American girls with obesity and 96 African-American girls without obesity residing in rural South Carolina, Participation in vigorous (greater than or equal to 6 METs) (VPA) or moderate and vigorous physical activity (greater than or equal to 4 METs) (MVPA) was assessed on three consecutive days using the Previous Day Physical Activity Recall, Cardiorespiratory fitness was assessed using the PWC 170 cycle ergometer test, Upper body strength was determined at two sites via isometric cable tensiometer tests, Relative to their counterparts without obesity, girls with obesity reported significantly fewer 30-minute blocks of VPA (0.90 +/- 0.14 vs. 1.3 +/- 0.14) and MVPA (1.2 +/- 0.18 vs. 1.7 +/- 0.16) (p<0.01), Within the entire sample, VPA and MVPA were inversely associated with body mass index (r=-0.17 and r=-0.19) and triceps skinfold thickness (r=-0.19 and r=-0.22) (p<0.05), In the PWC 170 test and isometric strength tests, girls with obesity demonstrated absolute scores that were similar to, or greater than, those of girls without obesity; however, when scores were expressed relative to bodyweight, girls with obesity demonstrated significantly lower values (p<0.05). The results support the hypothesis that lack of physical activity and low physical fitness are important contributing factors in the development and/or maintenance of obesity in African-American girls.

Multiple criteria-based real-time decision making by autonomous city vehicles

This paper addresses the topic of real-time decision making for autonomous city vehicles, i.e. the autonomous vehicles’ ability to make appropriate driving decisions in city road traffic situations. After decomposing the problem into two consecutive decision making stages, and giving a short overview about previous work, the paper explains how Multiple Criteria Decision Making (MCDM) can be used in the process of selecting the most appropriate driving maneuver.