On combining the beam path of similar wavelength lasers for dual-laser Thomson scattering.

A novel method for the path combination of two lasers with very similar wavelengths has been implemented to enable the evaluation of a dual-laser calibration Thomson scattering (TS) technique. The first experimental test of this TS technique has been performed in a RFX-mod plasma device, where, due to experimental constraints, the combination of a Nd:YAG (λ = 1064 nm) and a Nd:YLF (λ = 1053 nm) laser system was the only viable choice available. The method requires that the beam path of both lasers be combined into a single path with the same polarization. This presents a unique challenge due to the small difference between the two laser wavelengths. In this paper, we describe two methods for beam combination: first via a prism, eventually dismissed as unpractical, and second via a polarizing beam splitter in reverse with a dual-wavelength waveplate. We detail the optical setup, waveplate design, and successful implementation of this second method.

Patient-reported outcomes after oesophagectomy in the multicentre LASER study.

BACKGROUND: Data on the long-term symptom burden in patients surviving oesophageal cancer surgery are scarce. The aim of this study was to identify the most prevalent symptoms and their interactions with health-related quality of life. METHODS: This was a cross-sectional cohort study of patients who underwent oesophageal cancer surgery in 20 European centres between 2010 and 2016. Patients had to be disease-free for at least 1 year. They were asked to complete a 28-symptom questionnaire at a single time point, at least 1 year after surgery. Principal component analysis was used to assess for clustering and association of symptoms. Risk factors associated with the development of severe symptoms were identified by multivariable logistic regression models. RESULTS: Of 1081 invited patients, 876 (81.0 per cent) responded. Symptoms in the preceding 6 months associated with previous surgery were experienced by 586 patients (66.9 per cent). The most common severe symptoms included reduced energy or activity tolerance (30.7 per cent), feeling of early fullness after eating (30.0 per cent), tiredness (28.7 per cent), and heartburn/acid or bile regurgitation (19.6 per cent). Clustering analysis showed that symptoms clustered into six domains: lethargy, musculoskeletal pain, dumping, lower gastrointestinal symptoms, regurgitation/reflux, and swallowing/conduit problems; the latter two were the most closely associated. Surgical approach, neoadjuvant therapy, patient age, and sex were factors associated with severe symptoms. CONCLUSION: A long-term symptom burden is common after oesophageal cancer surgery.

Hospital outbreak of linezolid-resistant and vancomycin-resistant ST80 Enterococcus faecium harbouring an optrA-encoding conjugative plasmid investigated by whole-genome sequencing.

BACKGROUND: Linezolid is an antibiotic used to treat infections caused by multi-drug-resistant Gram-positive bacteria. Linezolid resistance in enterococci has been reported with increasing frequency, with a recent rise in resistance encoded by optrA, poxtA or cfr. AIM: To investigate a hospital outbreak of linezolid- and vancomycin-resistant Enterococcus faecium (LVREfm) using whole-genome sequencing (WGS). METHODS: Thirty-nine VREfm from patient screening (19 isolates, 17 patients) and environmental sites (20 isolates) recovered in October 2019 were investigated. Isolates were screened using polymerase chain reaction for optrA, poxtA and cfr, and underwent Illumina MiSeq WGS. Isolate relatedness was assessed using E. faecium core genome multi-locus sequence typing (cgMLST). One LVREfm underwent MinION long-read WGS (Oxford Nanopore Technologies) and hybrid assembly with MiSeq short-read sequences to resolve an optrA-encoding plasmid. FINDINGS: Twenty isolates (51.3%) were LVREfm and optrA-positive, including the LVREfm from the index patient. A closely related cluster of 28 sequence type (ST) 80 isolates was identified by cgMLST, including all 20 LVREfm and eight linezolid-susceptible VREfm, with an average allelic difference of two (range 0-10), indicating an outbreak. Nineteen (95%) LVREfm harboured a 56,684-bp conjugative plasmid (pEfmO_03). The remaining LVREfm exhibited 44.1% sequence coverage to pEfmO_03. The presence of pEfmO_03 in LVREfm and the close relatedness of the outbreak cluster isolates indicated the spread of a single strain. The outbreak was terminated by enhanced infection prevention and control (IPC) and environmental cleaning measures, ceasing ward admissions and ward-dedicated staff. CONCLUSION: WGS was central in investigating an outbreak of ST80 LVREfm. The rapid implementation of enhanced IPC measures terminated the outbreak.

On the analysis of inhomogeneous magnetic field spectrometer for laser-driven ion acceleration.

We present a detailed study of the use of a non-parallel, inhomogeneous magnetic field spectrometer for the investigation of laser-accelerated ion beams. Employing a wedged yoke design, we demonstrate the feasibility of an in-situ self-calibration technique of the non-uniform magnetic field and show that high-precision measurements of ion energies are possible in a wide-angle configuration. We also discuss the implications of a stacked detector system for unambiguous identification of different ion species present in the ion beam and explore the feasibility of detection of high energy particles beyond 100 MeV/amu in radiation harsh environments.

Metachronous adenocarcinoma of the remnant oesophagus 15 years following multimodal therapy.

A 53-year-old man underwent neo-adjuvant chemo-radiotherapy and a 2 stage oesophagectomy for a junctional oesophageal tumour in 1996. In March 2012, a metachronous oesophageal tumour was identified, 7cm above the anastomotic margin, on a background of non-inflamed squamous mucosa. He is currently being managed with chemo-radiotherapy. Oesophageal cancer is associated with a historically poor survival rate, with primary concerns being local recurrence or death from disseminated disease. This case highlights the challenges which must be faced, as treatment strategies improve and consequently survival rates increase.

Factors involved in unplanned admissions from general surgical day-care in a modern protected facility.

The aim in this audit study was to identify the rate of and the reasons for unanticipated admissions in general day surgery. All day ward procedures performed during the one year period from January 2011 to January 2012 were reviewed. Of 560 procedures performed, 25 (4.4%) patients were admitted. The age range of the patients admitted was from 26 to 83 years. The average BMI of the admitted patient was 28.9 (range 24-39).The average stay in hospital was 1.7 days (range 1-3 days). The reason for admission was potentially preventable in ten (40%) patients. This included eight (80%) out of ten admissions for control of postoperative pain, nausea and vomiting. Two (20%) were admitted for surgical observation due to high risk of bleeding. Fifteen (60%) of admissions were due to a non-preventable source, including 5 with a drain inserted at a perceived difficult laparoscopic cholecystectomy, 5 for urinary retention post open inguinal hernia repair, 2 for a cardiology review and 2 for further urgent investigations because of an unexpected intraoperative finding of malignancy. The rate of un-planned admission can be reduced by controlling potentially preventable causes, however a small contribution from unexpected scenarios is inevitable.

Management of maple syrup urine disease in the peri-operative period.

Maple syrup urine disease (MSUD) has an incidence of 1:125,000 newborns in Ireland. Patients, when fasting, or in a catabolic state build up toxic metabolites leading to progressive neurological dysfunction. We describe the necessary peri-operative management of a patient with MSUD who developed symptomatic gallstones requiring a laparoscopic cholecystectomy.

Double trouble--duplication of the gallbladder requiring repeat laparoscopic cholecystectomy.

Duplication of the gallbladder is a surprisingly common phenomenon. Clinically, these patients present with straightforward gallbladder pathologies. It is a challenging preoperative diagnosis on ultrasound, and most cases are diagnosed intra-operatively. We present a case of gallbladder duplication, where the patient presented with biliary colic, had a straightforward laparoscopic cholecystectomy, and then represented with biliary colic four years later.

Clinicopathologic features of sentinel node metastases predictive of positive axillary clearance in grade 1 invasive breast carcinoma.

BACKGROUND: Sentinel node (SN) biopsy is widely used to stage breast carcinoma and, when positive, typically leads to axillary clearance (AC). AIMS: This study assesses clinicopathologic features of grade 1 breast carcinoma SNs with the aim of identifying a group of patients, who are likely to have a negative AC and can, therefore, safely be spared further surgery. RESULTS: Two hundred and forty-seven patients with grade 1 invasive carcinoma were identified, of whom 29 had a positive SN. Four patients (13.8%) had a positive AC. Positive AC occurred in 3 of 6 (50%) patients whose SN showed extranodal extension (EE), but in only 1 of 23 (4.3%) patients without EE. All patients were staged as pN1(sn) following SN biopsy: only one, who had a 5.27 mm metastasis with EE, was pN2 following AC. CONCLUSIONS: Extranodal extension is a significant predictor of a positive AC in this group. In its absence, AC did not alter the post-SN biopsy pN stage.

Potential impact of text message reminders on non-attendance at outpatient clinics.

BACKGROUND: Non-attendance at outpatient clinic leads to significant time wasting and inefficient use of resources. AIMS: To establish the magnitude of the problem of clinic non-attendance and to ascertain the potential impact of a simple strategy to reduce inefficiency in Irish healthcare. METHODS: The number of patients due to attend general surgical clinic in a single year was ascertained. Telephone questionnaire of 97 patients who failed to attend was performed. A survey of potential impact of text message reminder was conducted. RESULTS: Appointments were sent to 18,362 patients. Of these, 31% (n = 5692) were new to clinic. The rate of non-attendance was 16.8% (n = 3085). Varied reasons were given for non-attendance. Text message reminder would encourage 51% of those surveyed to attend or cancel in advance. CONCLUSION: The rate of non-attendance is 17%. A reminder would eradicate more than half of non-attendance, allowing significantly more new patients to be seen, translating to more efficient use of clinic time.

Anterior displacement correlates with neurological impairment in cervical facet dislocations.

We studied all patients with either unifacetal or bifacetal dislocations treated in our National Spinal Injuries Unit between January 1996 and December 2000. There were 25 cases, of which 13 were unifacetal and 12 bifacetal. Craniocervical traction was employed in 21 cases and closed reduction achieved in 11. Eighteen patients underwent surgical stabilisation. Traction weights of up to 36 kg were employed, but there was no relationship found between the level of dislocation and traction weight. Anterior translation was measured by a newly described method, and we found a statistically significant correlation between the neurological score on admission and the degree of anterior translation.

Lower limb dysesthesia--an ominous sign in lumbar fractures.

Attempts at diagnosing dural lacerations secondary to fractures of the lumbar vertebrae on plain radiographs has varied considerably. If undiagnosed these injuries can cause serious complications. We present a clinical sign not previously documented to our knowledge. Plain radiographs in this case failed to show significant canal compromise but excessive hip pain, with the limb held in a characteristic posture, heralded cauda equina injury in a burst lumbar fracture. The limb was held in hip and knee flexion, with resistance to passive extension due to lower limb dysesthesia. This sign helped in determining the investigation and treatment of our patient.

Methylprednisolone in acute spinal cord injuries.

BACKGROUND: Methylprednisolone is the only neuroprotective therapy advocated in acute non-penetrating spinal cord injury. Trials indicate improved neurological outcome following early administration of a high dose regime. The National Spinal Injuries Unit (NSIU) has promoted this regime by a simple laminated poster sent to all Irish A&E departments. AIM: To assess the use of methylprednisolone in patients with spinal cord injuries. METHODS: A retrospective audit of patient data for all patients admitted with traumatic neurological impairment over a 12-month period. RESULTS: One hundred ninety-six patients were admitted during the study period, 28 (14%) received intravenous methylprednisolone of which six had clear records documenting compliance. One patient received both dexamethasone and methylprednisolone in high doses and three had incorrect bolus dosages administered. Six patients received methylprednisolone infusion longer than the protocol, while five patients were given infusions shorter than recommended. Three patients were admitted to the unit that could have received the steroid regime at the point of transfer. CONCLUSIONS: There was poor documentation of prescription orders and timing of administration. Only six patients had clear documentation allowing confirmation of adherence to the protocol of the National Acute Spinal Cord Injury Study (NASCIS) III trial.