Custom solution for personal protective equipment (PPE) in the orthopaedic setting: retrofitting Stryker Flyte T5 PPE system.

The coronavirus disease 2019 pandemic has meant that there is growing pressure on hospital resources, not least the availability of appropriate personal protective equipment (PPE), particularly face masks and respirator masks. Within the field of orthopaedic surgery, it is a common sight to see surgeons wearing 'space suits' (SSs) which comprise a helmet, hood and surgical gown. In this study, the authors made modifications to two different SS systems to incorporate a high-efficiency particulate air (HEPA) filter into the fan inlet to assess their potential as re-usable PPE systems for surgeons with regard to protection from a virus spread via respiratory droplets. The testing was carried out using particle counters upstream and downstream on a mannequin wearing two different SS systems with and without modifications to the fan inlet. The results show that using a layer of HEPA filter, cut to size and sealed to the fan inlet in the helmet, will reduce downstream particulates at the user's mouth by >99.5%; this is equivalent to a respirator mask. HEPA filter material is relatively cheap and can be used repeatedly, making this a viable alternative to disposable, and even resterilized, respirator masks in the setting of a respiratory-droplet-spread viral pandemic.

Emergency Aeromedical Services in Ireland: A Single-Centre Study in 2014.

This retrospective analysis includes patients requiring Emergency Aeromedical Services (EAS) in 2014. The aim of this paper is to evaluate the HEMS service in a single centre and to accurately assess whether certain internationally validated criteria can predict admission rates better than the currently used criteria. Using the American College of Surgeons (ACS) trauma-related dispatch criteria, each case was retrospectively evaluated. Results showed the mean total criteria met were 2.73 (?=0.88) and 1.45 (?=0.82) in admitted and discharged patients respectively. The total criteria met had a significant predictive value on admission rates (p<0.05). Increased admission rates were shown in patients with a high Mechanism of Injury (MOI) (p<0.05). False positive rates of HEMS transfer were higher when applying the current criteria compared to the ACS criteria. ACS total criteria can predict admission in HEMS patients with a higher specificity than currently used guidelines.

Emergency aeromedical services in Ireland: a retrospective study for "MEDEVAC112".

AIM: This is a retrospective analysis of all consecutive patients requiring emergency aeromedical services (EAS) to a level II trauma centre. This analysis was performed to evaluate the new service to Tallaght Hospital in terms of: the criteria used for dispatch, an estimate of baseline efficiency of time critical management of patients, the cross-catchment transfer of patients. METHODS: Data were provided by the EAS with respect to the patients brought to Tallaght Hospital not including inter-facility transfers for the calendar year 2013. Using this information patient records were matched to the electronic database. Once patients were identified, their hospital journey was catalogued using chart review. Using Google Maps and the EAS data an estimated road-time was calculated. Specific dispatch criteria were unavailable, however, using five broad categories outlined by the American College of Surgeons (ACS) for trauma related dispatch criteria each case was evaluated. RESULTS: The EAS data had 52 cases which were reported to come to this unit. 48 patient records were accurately matched to this data. 25 % were discharged without speciality input. Seven patients died within 24 h only one of which was admitted under a speciality. 30 patients were admitted under specialist care with two requiring transfer to another centre. 80 % of admissions came under the primary management of the orthopaedic team. 11 patients required operative management, five required ICU management, three required chest drains and one patient required cardiac angiogram. Of the five dispatch criteria categories evaluated the mean number of criteria met was 3.1. CONCLUSION: 25 % of the patients were managed in the Emergency Department alone indicating an acceptable level of over-triage according to ACS guidelines. When comparing the dispatch criteria met for this 25 % there was no statistical difference compared with the other 75 %. Sensitivity and specificity analyses have looked at the question of dispatch criteria before and our data are comparable with international evidence. We suggest that further research be undertaken to develop this service to improve activation criteria and thereby the entire service delivered.

Implementation of a surgical handover tool in a busy tertiary referral centre: a complete audit cycle.

BACKGROUND: The implementation of the European work-time directive has created increased transitions of care during weekends as doctors adhere to a shift-work structure. This raises concerns over continuity of care and patient safety. To address this, doctors must develop a time efficient yet safe system of handover of patients to the team on-call. Intuitively weekend care provides the ideal setting to develop a handover tool. AIM: To develop and implement a process of surgical handover and to improve weekend discharge rate on a surgical service. METHODS: Data was collected at three time-points over a 6 months period (October 2013-March 2014) encompassing development, implementation, re-evaluation and modification of the handover process. The outcomes measured were: number of inpatients, number of weekend discharges, length of stay (LOS) of inpatients recorded for the four weekends within the month, and total emergency response team (ERT) calls each month. RESULTS: Mean number of included patients each month was 294 (σ = 14). Following the introduction of weekend handover there was a 40 % increase in weekend discharges which was consistent for subsequent time-points (p < 0.05). Following the second intervention there was a statistically significant reduction in mean LOS from 13 to 5.4 days (p < 0.05) and the total number of ERT calls for the month reduced from 12 to 4 (p < 0.05). CONCLUSIONS: The standardisation of weekend handover using a combination of an electronic tool supplemented with verbal handover is feasible. It resulted in a significant improvement in surrogate markers of patient care quality.

Computerized tomography cisternography of the trigeminal nerve for stereotactic radiosurgery. Case report.

A-60-year-old man with medically intractable left-sided maxillary division trigeminal neuralgia had severe cardiac disease, was dependent on an internal defibrillator and could not undergo magnetic resonance imaging. The patient was successfully treated using computerized tomography (CT) cisternography and gamma knife radiosurgery. The patient was pain free 2 months after GKS. Contrast cisternography with CT scanning is an excellent alternative imaging modality for the treatment of patients with intractable trigeminal neuralgia who are unable to undergo MR imaging.

Calculation of enhanced dynamic wedge factors for symmetric and asymmetric photon fields.

A method is introduced to calculate wedge factors for an enhanced dynamic wedge (EDW). An analytic formula has been derived that allows the determination of wedge factors at the center of symmetric and asymmetric photon fields. The formalism is an extension of the "MU fraction approximation," which holds that the dynamic wedge factor is equal to the fraction of MU delivered to the point of calculation. Extensive data are presented, comparing measured enhanced dynamic wedge factors with the current method and the MU fraction model for both symmetric and asymmetric fields. For both 6 and 18 MV photons, the current method demonstrates improved results: Agreement to within 1% is obtained in all symmetric fields and within 2% for all asymmetric fields compared with discrepancies of up to 4% obtained with the MU fraction model.

Collimator (head) scatter at extended distances in linear accelerator-generated photon beams.

PURPOSE: A calculation formalism is proposed to predict variation of head scatter as a function of field size and treatment distance. METHODS AND MATERIALS: Assuming that the head scatter for the linear accelerator studied was contributed predominantly by the flattening filter, a formalism was devised to predict beam intensity as a function of distance from the target position. The method used the concept of an equivalent collimator field in which a given field at any distance can be equated to a field at the isocenter such that the extent of the flattening filter seen at the two positions is the same. RESULTS: The equation derived from the concept of equivalent collimator field size predicated change in head scatter with distance to within 0.5% for collimator field sizes ranging from 8 x 8 to 40 x 40 cm and distances up to 300 cm from the target. CONCLUSIONS: Considering flattening filter to be the main source of head scatter, the observed deviation from inverse square law for extended treatment distances can be accounted for by an equivalent collimator field size, which sees the same extent of the flattening filter at the isocenter as the field at the given distance.

Calculation of dose in asymmetric photon fields.

A method is introduced to calculate monitor units to points off axis. Extensive data are presented comparing this method with measured values of dose per monitor unit on the central ray of asymmetric fields produced by a variety of linear accelerators. The technique demonstrates improvement over existing methods that use large-field profile data. The method is found to be both simple and accurate: Agreement within +/- 2% is obtained using parameters readily available within the clinic.

Stereotactic radiosurgery for recurrent malignant gliomas.

PURPOSE: To evaluate the role of stereotactic radiosurgery in the management of recurrent malignant gliomas. PATIENTS AND METHODS: We treated 35 patients with large (median treatment volume, 28 cm3) recurrent tumors that had failed to respond to conventional treatment. Twenty-six patients (74%) had glioblastomas multiforme (GBM) and nine (26%) had anaplastic astrocytomas (AA). RESULTS: The mean time from diagnosis to radiosurgery was 10 months (range, 1 to 36), from radiosurgery to death, 8.0 months (range, 1 to 23). Twenty-one GBM (81%) and six AA (67%) patients have died. The actuarial survival time for all patients was 21 months from diagnosis and 8 months from radiosurgery. Twenty-two of 26 patients (85%) died of local or marginal failure, three (12%) of noncontiguous failure, and one (4%) of CSF dissemination. Age (P = .0405) was associated with improved survival on multivariate analysis, and age (P = .0110) and Karnofsky performance status (KPS) (P = .0285) on univariate analysis. Histology, treatment volume, and treatment dose were not significant variables by univariate analysis. Seven patients required surgical resection for increasing mass effect a mean of 4.0 months after radiosurgery, for an actuarial reoperation rate of 31%. Surgery did not significantly influence survival. At surgery, four patients had recurrent tumor, two had radiation necrosis, and one had both tumor and necrosis. The actuarial necrosis rate was 14% and the pathologic findings could have been predicted by the integrated logistic formula for developing symptomatic brain injury. CONCLUSION: Stereotactic radiosurgery appears to prolong survival for recurrent malignant gliomas and has a lower reoperative rate for symptomatic necrosis than does brachytherapy. Patterns of failure are similar for both of these techniques.

Flow cytometric analysis of the expression of murine B and T surface markers from birth to adulthood.

The proportion of nucleated splenocytes bearing B-lymphocyte markers B220, surface IgM (sIgM) and sIgD, as well as the T-lymphocyte markers Thy 1.2, CD5, CD8a and CD4 were quantitated by flow cytometric analysis (FACS) throughout postpartum development in the A/J mouse. Full expression of B lymphocyte markers was achieved much sooner than expression of T lymphocyte markers. This was especially true for B220, which was found on 8% of all splenocytes at day 5 and reached adult levels (47-50%) by weaning at day 22. Expression of sIgM and sIgD were 13% and 9%, respectively, of all splenocytes at day 5 with mature levels not expressed until day 35 postpartum (approximately 36% of cells were positive for these markers). T lymphocyte markers, on the other hand, did not reach full expression until sexual maturity. For example, Thy 1.2 expression was 8% on day 5 and did not reach mature levels (28-30%) until day 56. CD5 closely paralleled Thy 1.2 expression rising from only 2% on day 5 to 27% by day 56. Likewise, CD8a and CD4 marker development paralleled one another with CD8a rising from 1% on day 5 to 10% by day 56 and CD4 rising from 5% on day 5 to 19% by day 56. These data demonstrate the variability in the time of appearance and rate of maturation of the various lymphocyte cell surface markers during postpartum development. They also serve as a reference to identify alterations in lymphocyte development created by immunodeficiency diseases.

Does preoperative computed tomography scanning aid assessment of oesophageal carcinoma?

In this study 50 patients (36 male, 14 female) with oesophageal carcinoma have been examined preoperatively by computed tomography. Three parameters were assessed, nodal involvement, invasion of adjacent organs, and metastatic disease. For all patients the computed tomography findings were correlated with the subsequent surgical and pathological findings. Sensitivity for both invasion and node involvement is low (36% to 67%). Specificity however, is high (85% to 95%). Computed tomography is therefore relatively reliable when it predicts a 'negative result' for either invasion or node involvement. However, its predictive value for a positive result is not as reliable.