Does screening neonates in the neonatal intensive care unit for Pseudomonas aeruginosa colonization help prevent infection?

BACKGROUND

Pseudomonas aeruginosa (PA) is a Gram-negative environmental organism that can cause severe infection in immunosuppressed patients, including preterm neonates. In recent years, it has become common practice to screen neonates for PA colonization.

AIM

To assess the value of screening neonates for PA in (1) predicting the risk of developing severe PA infection and (2) directing infection control practice.

METHODS

Between August 2012 and September 2015, babies admitted to the neonatal intensive care unit (NICU) at North Bristol NHS Trust were screened routinely for PA colonization on admission and weekly thereafter. Data were also collected on babies who developed PA infection. Environmental samples from the NICU were tested for the presence of PA. Variable number tandem repeat (VNTR) typing was performed on all strains of PA from babies and the environment.

FINDINGS

No babies with positive screens subsequently developed PA infection. There was no VNTR strain evidence supporting cross-infection from the environment or other babies.

CONCLUSION

Screening neonates for PA did not identify babies who subsequently developed PA infection. Following cessation of screening in September 2015, there was no increase in the number of babies identified with PA infection.

Utility of post-traumatic amnesia in predicting 1-year productivity following traumatic brain injury: comparison of the Russell and Mississippi PTA classification intervals

BACKGROUND

Duration of post-traumatic amnesia (PTA) correlates with global outcomes and functional disability. Russell proposed the use of PTA duration intervals as an index for classification of traumatic brain injury (TBI) severity. Alternative duration-based schemata have been recently proposed as better predictors of outcome to the commonly cited Russell intervals.

OBJECTIVE

Validate a TBI severity classification model (Mississippi intervals) of PTA duration anchored to late productivity outcome, and compare sensitivity against the Russell intervals.

METHODS

Prospective observational data on TBI Model System participants (n=3846) with known or imputed PTA duration during acute hospitalisation. Productivity status at 1-year postinjury was used to compare predicted outcomes using the Mississippi and Russell classification intervals. Logistic regression model-generated curves were used to compare the performance of the classification intervals by assessing the area under the curve (AUC); the highest AUC represented the best-performing model.

RESULTS

All severity variables evaluated were individually associated with return to productivity at 1&emsp14;year (RTP1). Age was significantly associated with RTP1; however, younger patients had a different association than older patients. After adjustment for individually significant variables, the odds of RTP1 decrease by 14% with every additional week of PTA duration (95% CI 12% to 17%; p<0.0001). The AUC for the Russell intervals was significantly smaller than the Mississippi intervals.

CONCLUSIONS

PTA duration is an important predictor of late productivity outcome after TBI. The Mississippi PTA interval classification model is a valid predictor of productivity at 1&emsp14;year postinjury and provides a more sensitive categorisation of PTA values than the Russell intervals.

A multicentre study on the clinical utility of post-traumatic amnesia duration in predicting global outcome after moderate-severe traumatic brain injury

BACKGROUND

Past research shows that post-traumatic amnesia (PTA) duration is a particularly robust traumatic brain injury (TBI) outcome predictor, but low specificity limits its clinical utility.

OBJECTIVES

The current study assessed the relationship between PTA duration and probability thresholds for Glasgow Outcome Scale (GOS) levels.

METHODS

Data were prospectively collected in this multicentre observational study. The cohort was a consecutive sample of rehabilitation patients enrolled in the National Institute on Disability and Rehabilitation Research funded TBI Model Systems (n = 1332) that had documented finite PTA duration greater than 24 h, and 1-year and 2-year GOS.

RESULTS

The cohort had proportionally more Good Recovery (44% vs 39%) and less Severe Disability (19% vs 23%) at year 2 than at year 1. Longer PTA resulted in an incremental decline in probability of Good Recovery and a corresponding increase in probability of Severe Disability. When PTA ended within 4 weeks, Severe Disability was unlikely (<15% chance) at year 1, and Good Recovery was the most likely GOS at year 2. When PTA lasted beyond 8 weeks, Good Recovery was highly unlikely (<10% chance) at year 1, and Severe Disability was equal to or more likely than Moderate Disability at year 2.

CONCLUSIONS

Two PTA durations, 4 weeks and 8 weeks, emerged as particularly salient GOS probability thresholds that may aid prognostication after TBI.

Design Optimization of Single-Port Minimally Invasive Intervention Devices

Despite the success of multiple-port minimally invasive intervention (MII) systems, current research is fast moving away from standard, kinematically rigid MII instruments toward more flexible, highly articulated devices, such as robotic catheters, probes, and forceps. These new devices afford surgeons the same dexterity and range of motion as multiple-port systems while using only a single incision. Single-port MII devices hold the promise of facilitating procedures in small, geometrically complex spaces, such as those seen cardiothoracic surgery, with even lower risks of infection and patient discomfort than possible with multiple-port systems. However, the mechanical sophistication of these robotic devices requires careful consideration of morphological design to ensure that the complexity and cost of design is not economically prohibitive enough to outweigh the clinical benefits of improved robot flexibility. This study focuses on the intelligent design of a kinematically redundant, single-port MII robot architecture by way of morphological optimization. This MII device morphology is optimized to access the cardiothoracic cavity through a single 12 mm subxiphoid port and reach several regions of interest, consistent with procedures such as epicardial ablation and therapeutic substance injection, with minimal physiologic disturbance. The optimization process employs a recently developed morphological fitness metric to measure a candidate morphology's ability to navigate the cardiothoracic environment and perform surgical maneuvers with high end-effector flexibility while maintaining safe distances from anatomical structures. This fitness metric uses a Jacobian-based formulation to quantify a robot's capacity to avoid collisions with motion impediments and to minimize the mechanical torque required for the intended task. In addition to performance-based criterion, this optimization process also considers design factors such as part manufacturability and expense which heavily influence economic feasibility. Morphological optimization is performed by searching the mechanical design parameter space, which consists of part dimensions and linkage types, using genetic algorithms. The execution of specific surgical maneuvers is simulated for each candidate morphology until the fitness metric is maximized. Final simulations of the optimized device morphology working in the cardiothoracic cavity are performed to demonstate the functional advantages of the optimized single-port robot over current multiple-port systems.

Isolation of antibodies which neutralise the activity of early pregnancy factor

Early pregnancy factor (EPF) is a secreted protein with growth regulatory and immunomodulatory properties. It functions as an autocrine growth factor for tumour cells and as an autocrine or paracrine growth factor for regenerating normal cells. Anti-EPF antibodies have demonstrable anti-tumour activity and, as a result, hybridomas which produce such antibodies are unstable. In this study, the phage display antibody techniques have been investigated as a means of producing recombinant anti-EPF antibodies. Mice were immunised with synthetic peptides which correspond to the N or C terminal regions of EPF, and their splenic tissue was used to make combinatorial antibody libraries. The Fab repertoire was displayed on the surface of phage and panned over recombinant EPF. Reactive Fabs were identified by ELISA and their binding was characterised by BIAcore analysis and functional studies. Three libraries with a size of greater than 5x10(7)cfu were constructed and a total of 26 unique Fabs with specific reactivity against EPF were identified. Three Fabs were purified and of these one demonstrated strong EPF neutralising activity, one had intermediate activity and the other was not neutralising. Phage display has provided the means of circumventing the problems of anti-EPF hybridoma development and has resulted in the production of antibodies with potential applications in the diagnosis of pregnancy and the diagnosis and therapy of cancer.

Advanced life support: retention of registered nurses' knowledge 18 months after initial training

In 1996, The Wesley Hospital introduced a 2 day Advanced Life Support (ALS) course, targeted at all critical care registered nurses and medical officers. The purpose of this study was to explore the retention of theoretical knowledge and clinical skills of registered nurses who had successfully completed the 2 day ALS course 18 months previously and to establish effective retesting timeframes. The study utilised a repeated post-test measure design. Forty registered nurses participated in the study. Data were collected during ALS retesting using scores from a theoretical examination and from the results of four practical skill assessments (basic life support, airway management, defibrillation and code management). Using Wilcoxon test, data were analysed with and compared to the participant's original scores from the training program 18 months previously. The findings demonstrate that the participant's theoretical knowledge remained at an equivalent level over the 18 month timeframe. However, 18 months after successfully completing an ALS course, only 75 per cent (n = 30) of participants passed the practical skill assessment components, with the 25 per cent (n = 10) requiring a second attempt to pass. The implications from this study focus on the model of assessment utilised and the dichotomy between theoretical and practical skill assessment results. Additional study is required to determine the optimal timeframe for ALS retesting and educational strategies to help retain skills over time.

Posttraumatic amnesia: its relation to functional outcome

OBJECTIVE

To investigate the relation between duration of posttraumatic amnesia (PTA) and functional outcome in a traumatically brain injured population.

PATIENTS

Two hundred seventy-six patients with traumatic brain injury (TBI) who were admitted to a Level I university trauma center and required inpatient rehabilitation.

MEASURES

Duration of PTA was assessed by serial administrations of the Galveston Orientation Amnesia Test (GOAT). Functional Independence Measure (FIM) total scores, FIM cognitive and motor subscores, and Disability Rating Scale (DRS) scores were obtained at admission and discharge from inpatient rehabilitation.

RESULTS

Duration of PTA was a significant predictor of all admission and discharge DRS and FIM scores. Duration of PTA and age at the time of injury, in combination, contributed significantly to the prediction of the DRS score and FIM total, cognitive, and motor scores at discharge.

CONCLUSION

Duration of PTA appears to be a useful variable in predicting specific functional outcome in the TBI population receiving inpatient rehabilitation services. The use of age as a factor in addition to duration of PTA enhances the prediction of functional outcome.

Occipital status epilepticus: an unusual case of post-traumatic blindness

Post-traumatic seizures can be a cause of multiple clinical and behavioral abnormalities. We present an unusual case of post-traumatic epilepsy resulting in blindness. The patient was a 35-year-old female with a past history of toxemia of pregnancy who was assaulted, sustaining a traumatic brain injury (TBI). Glasgow Coma Score upon presentation to the emergency department was 10. Initial CAT scan was negative. Subsequent MRI revealed occipital edema. On examination, she was found to be blind in both eyes. Consistent with cortical blindness, extra-ocular movements, pupillary reflexes and fundoscopic examination were normal. Unusual scanning eye movements were noted. Electroencephalography (EEG) revealed epileptiform discharges in both occipital regions consistent with occipital status epilepticus. Seizures were eventually controlled with Phenytoin and Phenobarbital, with subsequent conversion to Carbamazepine. Central vision returned, but peripheral sight was never regained. Follow up EEG revealed no evidence of epileptiform activity. Post-traumatic occipital status epilepticus is rare. Cortical blindness in TBI patients with minimal occipital pathology on imaging is generally transient. This case points out the need for the treating rehabilitation professional to be vigilant in assessing for post-traumatic seizures in patients with persisting visual deficits.

Involving families in care within the intensive care environment: a descriptive survey

A descriptive survey design was utilised within a general intensive care environment, to describe the attitudes of nurses and relatives towards the provision of care by relatives to their critically ill loved one. Triangulation was employed utilising a questionnaire comprising a Likert scale, a checklist of participatory care activities, open questions and biographical questions. The total nurse population of the intensive care unit (ICU) was surveyed. 27 questionnaires were returned (a response rate of 75%). Of a possible 45 relatives surveyed, 20 returned questionnaires (a response rate of 44.4%). A high proportion of both the nurse and the relative samples (96.3% and 85% respectively) indicated their agreement with the concept of involving relatives in the physical care of their critically ill loved one. The results highlighted issues of personal choice for individual lay involvement and adequate information for families to become involved. For the nurse sample the major themes emergent were the problems of role adaptation for nurses and families involved, and building relationships. For the relative sample the categories emergent were adapting to the demanding ICU environment and identifying the parameters of their new caring role. The study suggests benefits, to both nurses and relatives, of lay participation in physical care of critically ill patients on the ICU environment.