Consciousness, coma, and caring for the brain-injured patient

A Review of Neuronal Pathways Associated With Consciousness

ABSTRACT

INTRODUCTION: Accurate communication of information regarding fluctuations in level of consciousness is critical. It is, important for nurses to understand terms related to consciousness to appropriately assess and implement plans of care. CONTENT: Although the neurobiology of consciousness is complex and multifaceted, consciousness can be conceptualized as having 2 distinct but interrelated dimensions: arousal and awareness. The different levels of consciousness are thought to fall on a continuum ranging from being fully awake to coma. CONCLUSION: This article focuses on the terms of consciousness, awareness, and arousal along with nursing implications where appropriate.

The Cue-Response Theory and Nursing Care of the Patient With Acquired Brain Injury

The cue-response theory is herewith proposed to replace the coma cue-response conceptual framework as a nursing theory for care of patients with acquired brain injury (ABI). After ABI, nurses assess patients and develop an understanding of their condition by interpreting meaning from physiologic and observational or behavioral cues. These interpretations form the basis for optimizing the timing of discrete nursing interventions; the outcome of which influences the trajectory toward recovery or toward secondary brain injury. The cue-response theory applies specifically for nurses' use to determine which interventions should be used and when those interventions should be carried out. The theory recognizes the knowledge potential and knowledge produced in the context of nursing care of all patients with ABI, not just those with coma, and broadens our understanding of how the timing of nursing interventions directly impacts secondary brain injury and the brain entropy state.

Music as Medicine: The Therapeutic Potential of Music for Acute Stroke Patients

Nurses caring for patients with acute stroke are likely to administer both music and medication with therapeutic intent. The administration of medication is based on accumulated scientific evidence and tailored to the needs of each patient. However, the therapeutic use of music is generally based on good intentions and anecdotal evidence. This review summarizes and examines the current literature regarding the effectiveness of music in the treatment of critically ill patients and the use of music in neurologically injured patients. The rationale for hypothesis-driven research to explore therapeutic music intervention in acute stroke is compelling.

Toward Solving the Sedation-Assessment Conundrum: Neurofunction Monitoring

The sedation-assessment conundrum is the struggle to balance the need for sedation against the need to awaken the patient and perform a neurologic examination. This article discusses the nuances of the sedation-assessment conundrum as well as approaches to resolve this and reduce the negative impact of abruptly stopping sedative infusions. Both oversedation and undersedation affect critically ill patients. This article discusses methods of assessing sedation and interpreting individualized patient responses to sedation. The use of neurofunction monitors and periods of sedation interruption are discussed within the context of addressing the sedation-assessment conundrum.

The Use of Automated Pupillometry in Critical Care

The neurologic examination (neuroexamination) is one of the most powerful tools available to nurses and physicians caring for patients with neurologic or neurosurgical illness. Assessing cranial nerve function is one of the most vital components of the neuroexamination. The pupillary light reflex helps to evaluate the status of the second and third cranial nerves and is one of the most well-known elements of the cranial nerve examination. Automated pupillometers have been developed that provide objective measures of size of the pupil and the responsiveness of the pupil to light (neuropupillary index).

Exploring the impact of augmenting sedation assessment with physiologic monitors

BACKGROUND

Pharmacological sedation is a necessary tool in the management of critically ill, mechanically ventilated patients. The intensive care unit (ICU) sedation strategy is to use the least amount of medication to meet safety and comfort goals. Titration of pharmacological agents is currently guided by clinical assessment tools. The purpose of this study was to determine whether the addition of a neurophysiological monitor, bispectral index (BIS), aided the ICU nurse in reducing the amount of drug used, compared to a clinical tool alone, in a general critical care population.

METHODS

In this prospective clinical trial, mechanically ventilated adults (N=300) were randomised to sedation assessment using only the observational assessment tool (RASS) or a combination of observational and physiologic measures (RASS+BIS). Subjects were enrolled from a medical ICU (N=154), a trauma ICU (N=72) and a general mixed-use ICU (N=74).

RESULTS

BIS-augmented sedation was only associated with the reduction of drug use when patients were sedated with propofol or narcotic agents (propofol [1.61 mg/kg/h vs. 1.77 mg/kg/h; p<0.0001], fentanyl [54.73 mcg/h vs. 66.81 mcg/h; p<0.0001], and hydromorphone [0.97 mg/h vs. 4.00 mg/h: p<0.0001] compared to RASS alone. In contrast, patients sedated with dexmedetomidine or benzodiazepines were given higher doses under the BIS-augmented dexmedetomidine [0.46 mcg/kg/h vs. 0.33 mcg/kg/h; p<0.0001], lorazepam [4.13 mg/h vs. 3.29 mg/h p<0.0001], and midazolam [3.73 mg/h vs 2.86 mg/h; p<0.0001]) protocol compared to clinical assessment alone.

CONCLUSION

The clinical evaluation of depth of sedation remains the most reliable method for the titration of pharmacological sedation in the critical care unit. However, BIS-augmented assessment is helpful in reducing the amount of propofol and narcotic medication used and may be considered an adjunct when these agents are utilised.

Acute assessment of brain injuries in ground-level falls

OBJECTIVE

The purpose of this study was to characterize traumatic brain injuries (TBI) sustained in ground-level falls (GLFs). The focus was on factors associated with acute computed tomographic (CT) findings.

METHODS

The sample included 575 subjects examined and treated at the Tampere University Hospital emergency department (ED). Retrospective data collection consisted of subject- and injury-related data and clinical information from the emergency department. All CT scans were analyzed and systematically coded.

RESULTS

Ground-level falls were the mechanism of injury in 48.3% (n = 278) of the subjects. In the GLF group, independent risk factors for acute traumatic CT findings were long-term alcohol abuse, older age, being found on the ground, and left temporoparietal and occipital location of direct head impact. There were no significant differences in the incidence of any intracranial traumatic lesion type between those with GLFs and other causes of TBI. None of the classic clinical TBI severity markers studied were associated with acute traumatic CT findings in patients with GLFs.

CONCLUSIONS

Older age and long-term alcohol abuse increase the likelihood of acute intracranial CT abnormalities. The pattern of intracranial traumatic CT findings does not differ from other causes of TBI. Clinical signs and indices of TBI severity did not predict traumatic CT findings.

Neurocritical care nursing research priorities

The science of nursing has long been discussed as a blending of the art and science of caring, and nursing research builds the evidence of support for nursing practice. Nurses and nursing care are key to successful neurocritical care research endeavors. Ideally nursing care should be evidence based and supported by solid research. The goal of nursing research is to expand the knowledge of caring for patients. Within the scope of nursing research, the priorities for research in neurocritical care should support this goal. In this manuscript, we discuss what we believe are the priorities of neurocritical care nursing research, the obstacles, and some possible solutions.

An observational pilot study of CSF diversion in subarachnoid haemorrhage

BACKGROUND

A primary focus of hospital treatment following admission for subarachnoid haemorrhage (SAH) is a prevention of cerebral artery vasospasm, which may result in ischaemic stroke. Intraventricular catheter (IVC) insertion to facilitate cerebral spinal fluid (CSF) drainage and intracranial pressure (ICP) monitoring may reduce the incidence or severity of vasospasm, but insufficient evidence exists from which clinicians may determine the best practice of CSF management.

AIMS

The aim of this study was to provide the pilot data to explore the impact of different methods of CSF drainage on outcomes in patients with SAH.

METHODS

In this non-randomized observational study, patients diagnosed with SAH who had ICP monitoring in situ were prospectively enrolled. Group assignment was determined by the method of external ventricular drainage (EVD) management prescribed by the attending physician prior to enrollment.

RESULTS

The 37 subjects were disproportionately divided: open-EVD group (N = 24) and monitor-ICP group (N = 13). There were no statistically significant differences by group assignment with respect to vasospasm, length of stay (LOS), highest average ICP, total CSF drained and disability upon discharge between groups.

CONCLUSIONS

Although not significant, our results show that the monitor-ICP group trended towards improved clinical outcomes. These results provide sufficient equipoise to support further research in ICP management in patients with SAH using a randomized clinical trial.

RELEVANCE TO CLINICAL PRACTICE

This study provides a solid foundation for the development of a randomized trial exploring two different methods of ICP monitoring and CSF diversion during the acute phase of care following aneurysm rupture.

Nursing interventions for critically ill traumatic brain injury patients

Neuroscience intensive care unit (ICU) nurses deliver a number of interventions when caring for critically ill traumatic brain injury (TBI) patients. Yet, there is little research evidence documenting specific nursing interventions performed. As part of a larger study investigating ICU nurse judgments about secondary brain injury, ICU nurses were asked to identify interventions routinely performed when caring for TBI patients. Quantitative and qualitative analyses indicate that all nurses routinely monitored hemodynamic parameters such as oxygen saturation, blood pressure, and temperature. Nurses were responsible for monitoring intracranial pressure and cerebral perfusion pressure approximately 50% of the time. Qualitative analyses revealed that additional nursing interventions could be categorized as neurophysiological interventions, psychosocial interventions, injury prevention interventions, and interventions to maintain a therapeutic milieu. Findings from this study provide evidence of the multifaceted role of the neuroscience ICU nurse caring for TBI patients and can be used in future research investigating the impact of nursing interventions on patient outcomes.