1.4 million Q factor Si3N4 micro-ring resonator at 780 nm wavelength for chip-scale atomic systems.

A silicon nitride micro-ring resonator with a loaded Q factor of 1.4 × 106 at 780 nm wavelength is demonstrated on silicon substrates. This is due to the low propagation loss waveguides achieved by optimization of waveguide sidewall interactions and top cladding refractive index. Potential applications include laser frequency stabilization allowing for chip-scale atomic systems targeting the 87Rb atomic transition at 780.24 nm. The temperature dependent wavelength shift of the micro-ring was determined to be 13.1 pm/K indicating that a minimum temperature stability of less than ±15 mK is required for such devices for wavelength locking applications. If a polyurethane acrylate top cladding of an optimized thickness is used then the micro-ring could effectively be athermal, resulting in reduced footprint, power consumption, and cost of potential devices.

Disordered activity? A review of the quality of epilepsy care provided to adults presenting to hospital with a seizure.

The National Confidential Enquiry into Patient Outcome and Death reviewed the quality of care provided to adults who presented to hospital following an epileptic seizure. Clinical and organisational changes are highlighted that aim to improve patient care and outcomes.

Delay in Transit: selected recommendations from the NCEPOD report on acute bowel obstruction.

Delayed in Transit, the report of the National Confidential Enquiry into Patient Outcome and Death (NCEPOD) on acute bowel obstruction (ABO), highlighted a number of areas for improvement in this group of patients. The overarching finding was that there were delays in the pathway of care for patients with ABO at every stage of the clinical pathway, including diagnosis, decision-making and the availability of operating theatres. Furthermore, basic measures including hydration, nutritional screening and nutritional assessment were noted to be deficient. Patients who were admitted to non-surgical wards had an increased risk of delayed treatment and subsequently a longer starvation period. There was room for improvement of nutritional screening and assessment on admission, throughout the hospital stay and on discharge. A selection of the report recommendations that address these areas requiring improvement is discussed here.

Delay in transit: the NCEPOD review of care provided to patients with acute bowel obstruction.

Acute bowel obstruction can occur in the small or large bowel and accounts for up to 10% of emergency surgical admissions. This high-risk group of patients requires careful management. Early diagnosis via computed tomography can help to prevent delays when surgery is required, which can impact patient outcomes.

The use of imaging in acute pancreatitis in United Kingdom hospitals: findings from a national quality of care study.

OBJECTIVE: To assess use of imaging in patients admitted to UK hospitals with acute pancreatitis (AP). METHODS: 4,479 patients had a diagnosis AP in the first 6 months of 2014. The National Confidential Enquiry into Patient Outcome and Death (NCEPOD) selected patients with more severe AP for case review. Clinicians completed 712 questionnaires and case reviewers assessed 418 cases. The use of imaging in patients with AP is reported. RESULTS: The common causes of AP were gallstones (46.5%) and alcohol excess (22%) with no cause identified in 17.5%. Imaging was needed to diagnose AP in 12%. 60.1% of patients had one or more CT scan. The timing of the CT scan(s) was appropriate in 90% of patients. The number of CTs was appropriate in all except 6.6% (equally split between too many and too few). AP collection intervention was radiological in 49/613 and surgical in 23/613. 69.8% had an ultrasound scan which diagnosed gallstones in 46.4% and bile duct dilatation in 12.9%. At least 21% had ultrasound scan inappropriately omitted. The National Confidential Enquiry into Patient Outcome and Death recommends gallstones are excluded in all patients with AP, including suspected alcohol-related AP. 29.8% underwent magnetic resonance cholangio--pancreatography diagnosing gallstones in 62.4%, bile duct dilatation in 25.4% and common bile duct stones in 14.4%. 20.6% had recurrent pancreatitis with gallstones accounting for a third. 17% with gallstone AP had a cholecystectomy within the guideline recommended time period. CONCLUSION: Imaging is rarely required for the diagnosis of AP. CT is used responsibly in AP management. Imaging should be used more to exclude gallstones, including in presumed alcohol related AP. Increased diagnostic efforts will not reduce recurrent biliary AP unless matched by earlier gallstone treatment. Advances in knowledge: Whilst CT is used responsibly in AP greater use of other diagnostic modalities is required to identify reversible causes, in particular gallstones, in order to prevent recurrent AP.

Severe Gastrointestinal Haemorrhage: Summary of a National Quality of Care Study with Focus on Radiological Services.

PURPOSE OF STUDY: To identify the remediable factors in the quality of care provided to patients with severe gastrointestinal (GI) bleeding. METHOD: All hospital admissions in the first four months of 2013 with ICD10 coding for GI bleeding who received a transfusion of 4 units or more of blood. Up to five cases/hospital randomly selected for structured case note peer review. National availability of GI bleeding services data derived from organisational questionnaire completed by all hospitals. RESULTS: 4563/29,796 (15.3%) of GI bleeds received 4 or more units of blood with a mortality rate of 20.2% compared to 7.3% without blood transfusion. 30.8% of GI bleeds received a blood transfusion. 32% (60/185) of hospitals admitting acute GI bleeds lacked 24/7 endoscopy. 26% (48/185) had on-site embolisation 24/7 with a further 34% (64/185) accessing embolisation by transfer within a validated formal network. Blood product use was inappropriate in 20% (84/426). Improved management, principally earlier senior gastroenterologist review and/or endoscopy, would have reduced blood product use in 25% (113/457). 14.5% (90/618) had a CT scan which identified the site of bleeding in 32% (29/90). 7.8% (36/459) underwent an Interventional Radiology (IR) procedure but a further 6.3% (21/33) should have had IR. 6% (36/586) underwent surgery with 21/36 for uncontrolled bleeding. In 20/35 IR was not considered despite the majority being suitable for IR. Overall 44% (210/476) received an acceptable standard of care according to peer review. CONCLUSIONS: 26 recommendations were made to improve the quality of care in GI bleeding, with six principle recommendations.

Traumatic implantation: a novel aetiology in the development of peritoneal mesothelioma.

Peritoneal mesothelioma is a rare intra-abdominal malignancy. Its aetiology has been thought to be due to either inhalation or ingestion of asbestos particles. We present a case of peritoneal mesothelioma developing as a result of a novel third route and the inoculation of fibres into the peritoneal cavity by penetrating trauma and direct transport. This case report highlights the important long term consequences of penetrating abdominal trauma and the need for vigilance in undertaking peritoneal toilet.

Does moderate celiac axis stenosis identified on preoperative multidetector computed tomographic angiography predict an increased risk of complications after pancreaticoduodenectomy for malignant pancreatic tumors?

OBJECTIVES: To identify any association between celiac artery compromise found on computed tomographic angiography and the incidence of postoperative and perioperative complications. METHODS: The computed tomographic angiograms of 36 patients who underwent the Whipple procedure for pancreatic adenocarcinoma were examined retrospectively. The association between the results and surgical course was investigated. RESULTS: Twelve patients (33%) had significant postoperative complications. Ten (28%) had evidence of celiac artery stenosis. Stenosis ranged from 20% to 60%. There was no evidence of a difference between the 2 groups. CONCLUSION: There seems to be no evidence of an increased risk of postoperative or perioperative complication in patients undergoing the Whipple procedure, with a celiac stenosis of up to 60%.

Preoperative staging accuracy of multidetector computed tomography in pancreatic head adenocarcinoma.

OBJECTIVE: To compare the preoperative computed tomography (CT) findings in patients with potentially operable pancreatic malignancy with findings at surgery. METHODS: In a retrospective analysis, 140 consecutive patients with carcinoma of the pancreatic head were studied. All were imaged using a standardized multidetector CT (MDCT) protocol. Patients with disease that was clearly inoperable were excluded. The remaining patients had their CT studies double-reported using a standard method. Images were scored for vascular involvement, tumor size, nodal disease, pancreatic duct diameter, and size of the gastrocolic trunk. Preoperative staging was compared with findings at surgery. RESULTS: One hundred forty patients presented with pancreatic head tumors. One hundred were not suitable for surgery. Forty patients were considered for curative surgery. For assessing preoperative operability, MDCT has an accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 72.7, 81.8, 68.2, 56, and 88.2%, respectively. Subjects with inoperable tumors tended to have larger tumors and more dilated pancreatic ducts (P = 0.04). CONCLUSIONS: There remains a group of patients with small pancreatic tumors that show early local dissemination, undetectable with high-resolution anatomical imaging.