Role transition: A descriptive exploratory study of assistant nurse clinicians in Singapore.

AIM: To explore the role-transition experiences of assistant nurse clinicians after their first year of appointment. BACKGROUND: The National Nursing Taskforce was set up in Singapore to examine the professional development and recognition of nurses. It created the assistant nurse clinician role as an avenue for the nurses' career development. The role was intended to assist nurse managers to guide the nursing team in the assessment, planning, and delivery of patient care. METHODS: A qualitative descriptive study design was adopted. A purposive sample of 22 registered nurses from six acute care institutions and two polyclinics in Singapore participated in the face-to-face interviews. An inductive content analysis approach was used to analyse the data. RESULTS: Four themes emerged: (a) promotion to assistant nurse clinician is a form of recognition and vindication; (b) there was uncertainty about the expected role of the assistant nurse clinician; (c) experience eases transition; and (d) there was a need for peer support, mentorship, and training. CONCLUSIONS: The job description of the assistant nurse clinician needs to be better defined to provide greater clarity about their clinical and administrative duties and what is expected of their performance. IMPLICATIONS FOR NURSING MANAGEMENT: It is essential for nurse managers to provide successful role-transition strategies to help the newly appointed assistant nurse clinicians to become efficient and effective leaders.

Go green! Reusing brain monitoring data containing missing values: a feasibility study with traumatic brain injury patients.

BACKGROUND: Despite the wealth of information carried, periodic brain monitoring data are often incomplete with a significant amount of missing values. Incomplete monitoring data are usually discarded to ensure purity of data. However, this approach leads to the loss of statistical power, potentially biased study and a great waste of resources. Thus, we propose to reuse incomplete brain monitoring data by imputing the missing values - a green solution! To support our proposal, we have conducted a feasibility study to investigate the reusability of incomplete brain monitoring data based on the estimated imputation error. MATERIALS AND METHODS: Seventy-seven patients, who underwent invasive monitoring of ICP, MAP, PbtO (2) and brain temperature (BTemp) for more than 24 consecutive hours and were connected to a bedside computerized system, were selected for the study. In the feasibility study, the imputation error is experimentally assessed with simulated missing values and 17 state-of-the-art predictive methods. A framework is developed for neuroclinicians and neurosurgeons to determine the best re-usage strategy and predictive methods based on our feasibility study. RESULTS/CONCLUSION: The monitoring data of MAP and BTemp are more reliable for reuse than ICP and PbtO (2); and, for ICP and PbtO (2) data, a more cautious re-usage strategy should be employed. We also observe that, for the scenarios tested, the lazy learning method, K-STAR, and the tree-based method, M5P, are consistently 2 of the best among the 17 predictive methods investigated in this study.

Cerebral oxygenation, vascular reactivity, and neurochemistry following decompressive craniectomy for severe traumatic brain injury.

OBJECT: This study addresses the changes in brain oxygenation, cerebrovascular reactivity, and cerebral neurochemistry in patients following decompressive craniectomy for the control of elevated intracranial pressure (ICP) after severe traumatic brain injury (TBI). METHODS: Sixteen consecutive patients with isolated TBI and elevated ICP, who were refractory to maximal medical therapy, underwent decompressive craniectomy over a 1-year period. Thirteen patients were male and 3 were female. The mean age of the patients was 38 years and the median Glasgow Coma Scale score on admission was 5. RESULTS Six months following TBI, 11 patients had a poor outcome (Group 1, Glasgow Outcome Scale [GOS] Score 1-3), whereas the remaining 5 patients had a favorable outcome (Group 2, GOS Score 4 or 5). Decompressive craniectomy resulted in a significant reduction (p < 0.001) in the mean ICP and cerebrovascular pressure reactivity index to autoregulatory values (< 0.3) in both groups of patients. There was a significant improvement in brain tissue oxygenation (PbtO(2)) in Group 2 patients from 3 to 17 mm Hg and an 85% reduction in episodes of cerebral ischemia. In addition, the durations of abnormal PbtO(2) and biochemical indices were significantly reduced in Group 2 patients after decompressive craniectomy, but there was no improvement in the biochemical indices in Group 1 patients despite surgery. CONCLUSIONS: Decompressive craniectomy, when used appropriately in protocol-driven intensive care regimens for the treatment of recalcitrant elevated ICP, is associated with a return of abnormal metabolic parameters to normal values in patients with eventually favorable outcomes.

Changes in brain biochemistry and oxygenation in the zone surrounding primary intracerebral hemorrhage.

BACKGROUND: While the management of primary intracerebral hemorrhage (ICH) remains controversial, there remains a subset of patients that undergo clot evacuation. This study aims to characterize brain physiology and biochemistry after surgery for this condition. METHODS: Thirty-six consecutive patients requiring ventilation for primary ICH had intracranial pressure (ICP), tissue oxygenation (PbO2) and cerebral microdialysis (CMD) monitoring. 28 patients with a Glasgow Outcome Score (GOS) of 1-3 formed group 1 while 5 patients with a GOS of 4-5 formed group 2. The control group consisted of 3 patients managed conservatively without surgery. FINDINGS: The mean PbO2 (24.5 +/- 20.8 mmHg) was higher in the patients in group 1 (poor outcome) compared with those in the control group (13.6 +/- 9.0 mmHg) (p < 0.001). Compared to patients in group 2, the patients in group 1 also had a higher PbO2 (p = 0.02) together with worse levels of lactate/pyruvate (L/P) ratio and glycerol (p < 0.001). In all 3 groups, ICP reduction to < 20 mmHg was achieved together with a return to of pressure reactivity (PRx) to < 0.3. CONCLUSIONS: In spontaneous ICH, derangements in the perilesional tissue demonstrated by local techniques of PbO2 monitoring and CMD are not seen in global indices such as the PRx.

Prediction of early mortality in primary intracerebral hemorrhage in an Asian population.

BACKGROUND: Primary intracerebral hemorrhage accounts for the relative minority of all strokes and yet is more fatal and disabling. Various prognostic models for mortality and functional outcome following primary intracerebral hemorrhage have been proposed, however there is little data which focuses on a multi-racial population profile characteristic of communities in South-East Asia. A reliable grading scale for this condition will allow for accurate risk stratification, treatment selection, resource allocation and possibly also aid in the definition of common enrollment criteria for clinical trials. METHODS: This study investigates an Asian population of primary intracerebral hemorrhage patients and defines using a variety of data mining techniques the clinical variables that significantly impact on early mortality. The models produced are then compared to ascertain which one optimally predicts this outcome. FINDINGS: Past history of stroke, known atrial fibrillation, use of warfarin, glucose level, presenting Glasgow Coma Scale (GCS) and pupil abnormality, post-resuscitation GCS and pupil abnormality, initial international normalized ratio (INR) and prothrombin time (PT) results, vomiting, seizure, total volume of clot, ventricular extension and hydrocephalus were significantly associated with early mortality. Logit with backward elimination showed that only age, presenting GCS, 1st INR result and total volume of clot were significantly associated with mortality in the final multivariate model. The use of the other data mining techniques yielded comparable results. CONCLUSIONS: The predictors for early mortality and poor outcome in primary intracerebral hemorrhage are similar in Asian and Western populations.

Effects of temperature changes on cerebral biochemistry in spontaneous intracerebral hematoma.

BACKGROUND: Fever worsens outcome in acute brain injury, presumably by accelerating secondary damage. Improved understanding of the pathophysiological processes that occur in spontaneous intracerebral hemorrhage (ICH) may help to determine if controlled normothermia might be of clinical benefit. METHODS: In this prospective observational study over a period of 18 months at the National Neuroscience Institute, Singapore, we examined the effects of temperature changes on brain biochemistry and tissue oxygenation in 25 consecutive patients with spontaneous primary putaminal hemorrhage. The patients were divided into 3 groups according to the mean brain temperature over a 72-hour monitoring period following surgery and standard medical measures to control post-operative brain swelling and secondary injury. FINDINGS: Patients that become spontaneously hypothermic with a mean brain temperature of less than 36 degrees centigrade (degrees C) had greater impairment in brain biochemistry as reflected by the worst brain lactate/pyruvate (L/P) ratio, glutamate and glucose dialysates. Brain tissue oxygenation, on the other hand, was highest and within normal limits in these spontaneously hypothermic patients. The hyperthemic group had similar L/P ratio, glycerol and glutamate levels when compared to the normothermic group. The glucose levels were found to be significantly different in all 3 groups. CONCLUSIONS: Extremes of temperature in spontaneous ICH, in particular--spontaneous hypothermia with a mean brain temperature of less than 36 degrees C, are associated with a poor outcome. Cerebral microdialysis can be used to detect these detrimental changes that occur.

Effects of glycaemic control on cerebral neurochemistry in primary intracerebral haemorrhage.

This was a pilot study to compare the cerebral haemodynamics and neurochemical changes in patients with primary basal ganglia haemorrhage (PBGH), who underwent conventional blood glucose level (BGL) control and intensive BGL control with continuous titrated insulin therapy. Patients admitted over an 18-month period with PBGH after evacuation of haematoma were retrospectively divided into two groups according to the method used for BGL control: the 'intensive' group consisted of patients who underwent continuous titrated insulin infusion to maintain a lower normoglycemic level of 4-8 mmol/L, and the 'conventional' group consisted of patients whose BGL was maintained at between 8.1 and 10.0 mmol/L using conventional 'sliding scale' bolus subcutaneous insulin administration. Data on cerebral haemodynamics, interstitial brain oxygenation (PtiO(2)) and neurochemical monitoring were collected via microcatheters inserted in the perihaemorrhagic penumbral region. A homogenous group of 12 patients with haemorrhage originating in the deep basal nuclei was identified. Five patients (42%) were included in the intensive group, and seven patients (58%) were included in the conventional group. The mean intracranial pressure, mean arterial pressure, BGL, extracellular (EC) lactate, EC glutamate, EC pyruvate and EC glycerol levels and the lactate/pyruvate ratio were found to be significantly lower (p<0.001) in the intensive group compared with the conventional group, but the mean PtiO(2) and amount of insulin administered were higher (p<0.001) in the intensive group. The mean cerebral perfusion pressure and EC glucose did not differ significantly between the two groups of patients. Maintenance of lower normoglycaemia (4-8 mmol/L) with continuous titrated insulin therapy is associated with improved cerebral haemodynamics, oxygenation and neurochemistry in the perihaemorrhagic penumbral region.

Outcome of severe head injured patients admitted to intensive care during weekday shifts compared to nights and weekends.

INTRODUCTION: Some studies have demonstrated an increased risk of death for patients admitted at nights or during weekends. This study was undertaken to investigate the demographic profile, medical interventions and outcome of severe head injury patients stratified according to day and time of admission to a specialised neurosciences intensive care unit (NICU). MATERIALS AND METHODS: A retrospective study using a prospectively maintained severe head injury database in a tertiary hospital. Admissions to the NICU were grouped into weekdays, weeknights and weekends. A comparison of patients admitted during the day and night hours were also made. RESULTS: A total of 838 severe head injury patients admitted to NICU were included in the study, of which 263 were admitted on weekdays, 327 on weeknights and 248 on weekends. More patients were admitted during the night (496) compared to during the day (342). There were no significant differences in the demographic profile, mechanism of injury, severity of injury, need for neurosurgical intervention, and duration of mechanical ventilation, intensive care unit (ICU) stay and mortality associated with day and time of admission. In multivariate analyses controlling for confounding factors, no statistically significant difference in ICU mortality was found with the day and time of admission. CONCLUSIONS: There were more severe head injury patients admitted to ICU at night and on weekends, with no significant difference in demographic profile, types of injuries, need for neurosurgical interventions and duration of ICU stay and mortality in a specialised NICU with adequate staffing and requisite diagnostic and therapeutic modalities available.

Hybrid outcome prediction model for severe traumatic brain injury.

Numerous studies addressing different methods of head injury prognostication have been published. Unfortunately, these studies often incorporate different head injury prognostication models and study populations, thus making direct comparison difficult, if not impossible. Furthermore, newer artificial intelligence tools such as machine learning methods have evolved in the field of data analysis, alongside more traditional methods of analysis. This study targets the development of a set of integrated prognostication model combining different classes of outcome and prognostic factors. Methodologies such as discriminant analysis, logistic regression, decision tree, Bayesian network, and neural network were employed in the study. Several prognostication models were developed using prospectively collected data from 513 severe closed head-injured patients admitted to the Neurocritical Unit at National Neuroscience Institute of Singapore, from April 1999 to February 2003. The correlation between prognostic factors at admission and outcome at 6 months following injury was studied. Overfitting error, which may falsely distinguish different outcomes, was compared graphically. Tenfold cross-validation technique, which reduces overfitting error, was used to validate outcome prediction accuracy. The overall prediction accuracy achieved ranged from 49.79% to 81.49%. Consistently high outcome prediction accuracy was seen with logistic regression and decision tree. Combining both logistic regression and decision tree models, a hybrid prediction model was then developed. This hybrid model would more accurately predict the 6-month post-severe head injury outcome using baseline admission parameters.

Use of programmable versus nonprogrammable shunts in the management of hydrocephalus secondary to aneurysmal subarachnoid hemorrhage: a retrospective study with cost-benefit analysis.

OBJECTIVES: The choice of programmable or nonprogrammable shunts for the management of hydrocephalus after aneurysmal subarachnoid hemorrhage (SAH) remains undefined. Variable intracranial pressures make optimal management difficult. Programmable shunts have been shown to reduce problems with drainage, but at 3 times the cost of nonprogrammable shunts. METHODS: All patients who underwent insertion of a ventriculoperitoneal shunt for hydrocephalus after aneurysmal SAH between 2006 and 2012 were included. Patients were divided into those in whom nonprogrammable shunts and those in whom programmable shunts were inserted. The rates of shunt revisions, the reasons for adjustments of shunt settings in patients with programmable devices, and the effectiveness of the adjustments were analyzed. A cost-benefit analysis was also conducted to determine if the overall cost for programmable shunts was more than for nonprogrammable shunts. RESULTS: Ninety-four patients underwent insertion of shunts for hydrocephalus secondary to SAH. In 37 of these patients, nonprogrammable shunts were inserted, whereas in 57 programmable shunts were inserted. Four (7%) of 57 patients with programmable devices underwent shunt revision, whereas 8 (21.6%) of 37 patients with nonprogrammable shunts underwent shunt revision (p = 0.0413), and 4 of these patients had programmable shunts inserted during shunt revision. In 33 of 57 patients with programmable shunts, adjustments were made. The adjustments were for a trial of functional improvement (n = 21), overdrainage (n = 5), underdrainage (n = 6), or overly sunken skull defect (n = 1). Of these 33 patients, 24 showed neurological improvements (p = 0.012). Cost-benefit analysis showed $646.60 savings (US dollars) per patient if programmable shunts were used, because the cost of shunt revision is a lot higher than the cost of the shunt. CONCLUSIONS: The rate of shunt revision is lower in patients with programmable devices, and these are therefore more cost-effective. In addition, the shunt adjustments made for patients with programmable devices also resulted in better neurological outcomes.

Post-traumatic hydrocephalus after ventricular shunt placement in a Singaporean neurosurgical unit.

Ventricular enlargement is a common finding after severe head injury and has a poor prognosis if associated with post-traumatic hydrocephalus (PTH). We retrospectively reviewed our head injury database and identified patients who suffered from severe head injury and subsequently had shunt insertion after a diagnosis of PTH. A total of 871 patients with severe head injury were admitted from April 1999 to December 2006. Twenty-three patients (2.6%) were diagnosed with post-traumatic hydrocephalus and had a shunt inserted. Multiple logistic regression analysis showed that age, and unilateral and bilateral decompressive craniectomy, were significant predictors of PTH. The timing of shunt placement was between 2 weeks and 5 months post-head injury with a mean interval of 70 days. Three patients developed complications after shunt insertion. Seventeen patients (74%) achieved improvement after shunt insertion while the remainder had no significant change in neurological status. Eleven patients (48%) had improvements in their Glasgow Coma Scale (GCS) score of ≥2 points, while six patients (26%) had a single-point improvement in their GCS score. At 1 year after shunting, 35% of patients had Glasgow Outcome Scale scores of 3 to 4. PTH is a condition that has an insidious onset with varying clinical and radiological presentations. The incidence is low but there is a significant benefit from ventricular shunt insertion. The use of cerebrospinal fluid dynamic studies, in addition to clinical and radiological findings, has the potential for better diagnosis and management of these patients.

A randomized, placebo-controlled pilot study of patients with spontaneous intraventricular haemorrhage treated with intraventricular thrombolysis.

Intraventricular hemorrhage (IVH) occurring after spontaneous intracerebral hemorrhage (ICH) is an independent risk factor for mortality. The use of intraventricular urokinase (Uk) to reduce intraventricular blood clot volume and improve outcome was investigated. Patients with IVH requiring external ventricular drainage were recruited and randomized into a double-blind placebo controlled study. Assessments of collected cerebrospinal fluid (CSF) haemoglobin (Hb) and serial CT scans were performed. The study outcomes were: infection rates, length of stay in the intensive care unit, survival, National Institutes of Health Stroke Scale score; and modified Rankin Scale scores. Our results showed an increase in both the drained CSF Hb concentration in patients treated with Uk compared to placebo and in the rate of resolution clot volume. No differences were found in the other outcome measures but there was a trend towards lowered mortality in the group treated with Uk. Therefore, intraventricular Uk resulted in faster resolution of IVH with no adverse events.

Prediction of outcome utilizing both physiological and biochemical parameters in severe head injury.

Traumatic brain injury is a major socioeconomic burden, and the use of statistical models to predict outcomes after head injury can help to allocate limited health resources. Earlier prediction models analyzing admission data have been used to achieve prediction accuracies of up to 80%. Our aim was to design statistical models utilizing a combination of both physiological and biochemical variables obtained from multimodal monitoring in the neurocritical care setting as a complement to earlier models. We used decision tree and logistic regression analysis on variables including intracranial pressure (ICP), mean arterial pressure (MAP), cerebral perfusion pressure (CPP), and pressure reactivity index (PRx), as well as multimodal monitoring parameters to assess brain tissue oxygenation (PbtO(2)), and microdialysis parameters to predict outcomes based on a dichotomized Glasgow Outcome Score. Further analysis was carried out on various subgroup combinations of physiological and biochemical parameters. The reliability of the head injury models was assessed using a 10-fold cross-validation technique. In addition, the confusion matrix was also used to assess the sensitivity, specificity, and the F-ratio. In all, 2,413 time series records were extracted from 26 patients treated at our neurocritical care unit over a 1-year period. Decision tree analysis was found to be superior to logistic regression analysis in predictive accuracy of outcome. The combined use of microdialysis variables and PbtO(2), in addition to ICP, MAP, and CPP was found have the best predictive accuracy. The use of physiological and biochemical variables based on a decision tree analysis model has shown to provide an improvement in predictive accuracy compared with other previous models. The potential application is for outcome prediction in the multivariate setting of advanced multimodality monitoring, and validates the use of multimodal monitoring in the neurocritical care setting to have a potential benefit in predicting outcomes of patients with severe head injury.