Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Preclinical medical students' usage of electronic devices in lectures: A cross-sectional study

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The Use of Tranexamic Acid for Traumatic Brain Injury with Contusions or Traumatic Subarachnoid Haemorrhage in the Elderly

Objective: To investigate the impact of Tranexamic Acid (TXA) as an initial non-operative treatment on the mortality rate of traumatic brain injury with contusions or traumatic subarachnoid haemorrhage in the elderly. Method: This was a seven-year retrospective study of consecutive patients admitted for traumatic brain injury with contusions or traumatic subarachnoid haemorrhage at Queen Mary Hospital from 2010-2016. Primary outcome was the overall mortality rate. Secondary outcomes included rate of deterioration requiring operation and the survival rate without operations. Result: In total 651 consecutive patients were identified. 81 patients had TXA (TXA group) while 570 did not have TXA (control group) during admission. The average age was 73.92 years old (95%CI 68.77-77.84 years old) for the TXA group versus 65.36 years old (95%CI 63.24-67.48 years old) for the control group (p=0.0062). The overall mortality rate with TXA was 7.40% versus 8.77% in the control group (OR 0.832 95%CI 0.345-2.007, p=0.682). The rate of deterioration requiring operation in the TXA group was 6.17% versus 16.3% in the control group (OR 0.337 95%CI 0.133-0.857, p=0.022). The survival rate with no operations in the TXA group was 88.89% versus 77.89% in the control group (OR 2.270 95%CI 1.104-4.667, p=0.026). Conclusion: In this study, patients in the TXA group was significantly older than that in the control group. The overall mortality rates were comparable in the two groups. The TXA group had a lower rate of operation. With the use of Tranexamic Acid, there were significantly more survivors without operations

Identification of blood meal sources of Lutzomyia longipalpis using polymerase chain reaction-restriction fragment length polymorphism analysis of the cytochrome B gene

An analysis of the dietary content of haematophagous insects can provide important information about the transmission networks of certain zoonoses. The present study evaluated the potential of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the mitochondrial cytochrome B (cytb)gene to differentiate between vertebrate species that were identified as possible sources of sandfly meals. The complete cytb gene sequences of 11 vertebrate species available in the National Center for Biotechnology Information database were digested with Aci I, Alu I, Hae III and Rsa I restriction enzymes in silico using Restriction Mapper software. The cytb gene fragment (358 bp) was amplified from tissue samples of vertebrate species and the dietary contents of sandflies and digested with restriction enzymes. Vertebrate species presented a restriction fragment profile that differed from that of other species, with the exception of Canis familiaris and Cerdocyon thous. The 358 bp fragment was identified in 76 sandflies. Of these, 10 were evaluated using the restriction enzymes and the food sources were predicted for four: Homo sapiens (1), Bos taurus (1) and Equus caballus (2). Thus, the PCR-RFLP technique could be a potential method for identifying the food sources of arthropods. However, some points must be clarified regarding the applicability of the method, such as the extent of DNA degradation through intestinal digestion, the potential for multiple sources of blood meals and the need for greater knowledge regarding intraspecific variations in mtDNA