Effect of gender on the reliability of COVID-19 rapid antigen test among elderly

Defining con-founders that affect the reliability of diagnostic tests for coronavirus disease 2019 is vital to breaking the chain of infection. The elderly population is a higher risk group for the emerging virus. However, gender seems to exert a critical role in modifying the infection risk among women owing to hormonal changes. The menopause transition is an exceptional period for older women where the protective and immunomodulatory effects of the estrogen hormone are lost. Accordingly, attention should be given to postmenopausal women since they will have an increased risk compared to their pre-menopausal peers.     

Clinical cerebral microdialysis: a methodological study

OBJECT: Clinical microdialysis enables monitoring of the cerebral extracellular chemistry of neurosurgical patients. Introduction of the technique into different hospitals' neurosurgical units has resulted in variations in the method of application. There are several variables to be considered, including length of the catheter membrane, type of perfusion fluid, flow rate of perfusion fluid, and on-line compared with delayed analysis of samples. The objects of this study were as follows: 1) to determine the effects of varying catheter characteristics on substance concentration; 2) to determine the relative recovery and true extracellular concentration by varying the flow rate and extrapolating to zero flow; and 3) to compare substance concentration obtained using a bedside enzyme analyzer with that of off-line high-performance liquid chromatography (HPLC). METHODS: A specially designed bolt was used to conduct two adjacent microdialysis catheters into the frontal cortex of patients with head injury or poor-grade subarachnoid hemorrhage who were receiving ventilation. One reference catheter (10-mm membrane, perfused with Ringer's solution at 0.3 microl/minute) was constant for all studies. The other catheter was varied in terms of membrane length (10 mm or 30 mm), perfusion fluid (Ringer's solution or normal saline), and flow rate (0.1-1.5 microl/minute). The effect of freezing the samples on substance concentration was established by on-line analysis and then repeated analysis after storage at -70 degrees C for 3 months. Samples assayed with the bedside enzyme analyzer were reassessed using HPLC for the determination of glutamate concentrations. CONCLUSIONS: Two adjacent microdialysis catheters that were identical in membrane length, perfusion fluid, and flow rate showed equivalent results. Variations in perfusion fluid and freezing and thawing of samples did not result in differences in substance concentration. Catheter length had a significant impact on substance recovery. Variations in flow rate enabled the relative recovery to be calculated using a modification of the extrapolation-to-zero-flow method. The recovery was approximately 70% at 0.3 microl/minute and 30% at 1 microl/minute (10-mm membrane) for all analytes. Glutamate results obtained with the enzyme analyzer showed good correlation with those from HPLC.     

Heart failure in hypertensive patients with left ventricular hypertrophy

Left ventricular hypertrophy (LVH) is supposed to be a useful marker of cardiovascular complications during the course of hypertension. Authors compared the presence of heart failure, left ventricular diastolic dysfunction and chronic atrial fibrillation in hypertensive patients with and without left ventricular hypertrophy defined by echocardiography. Hospital records of 192 hypertensives treated in our medical department during years 1996-1999 were analysed. Left ventricular hypertrophy was defined by echocardiography (Penn convention) as left ventricular mass index > 134 g/m2 in men and > 110 g/m2 in women. Presence of LVH was found in 128 patients (mean age 65.9 years), absence of LVH in 64 patients (mean age 64.8 years). Both groups of hypertensives were matched by demographic parameters, by the presence of hyperlipidemia, by smoking habits. Hypertensive patients with left ventricular hypertrophy were more often treated by ACE inhibitors. There were statistically significant more patients with heart failure, left ventricular diastolic dysfunction and chronic atrial fibrillation in LVH-positive patients than in LVH-negative once. There was also statistically significant lower ejection fraction (50.3 +/- 11.4% vs 56.5 +/- 7.4%) in LVH-positive patients than in LVH-negative once. Left ventricular hypertrophy in patients with hypertension brings usually a complicated course of the disease with a high contribution to the development of chronic heart failure.     

Laparoscopic Colorectal Surgery for Obese Patients: Decreased Conversions with the Hand-Assisted Technique

Background

Laparoscopic surgery benefits obese patients but technical difficulties associated with suboptimal exposure and access in these subjects may prompt conversion to open surgery. Hand-assisted laparoscopic surgery (HALS) confers advantages over standard laparoscopy (LAP) by facilitating tactile feedback, assisted dissection, and retraction. These benefits could be particularly valuable in obese patients, allowing completion of difficult laparoscopic procedures in this subgroup. Our aim was to compare intra-operative and post-operative outcomes of HALS and LAP approaches in obese patients undergoing colorectal resection at our institution.

Methods

A retrospective study of a prospectively maintained laparoscopic colorectal surgery database was performed. HALS and LAP cases performed in obese patients (body mass index (BMI)?>30) were identified and compared for the following outcomes: operative time, intra-operative complications, rate of conversion to open, blood loss, length of stay, post-operative morbidity, and mortality. Outcomes for the converted patients were included on an intention-to-treat basis for all primary analyses. A secondary analysis of nonconverted and converted cases was also performed.

Results

Over a 5-year period, 496 obese patients underwent laparoscopic colorectal resection; 86 HALS and 410 LAP cases. The two groups were comparable in terms of age, gender, BMI, and indications for surgery. Conversion to open surgery was less often necessary in HALS compared to LAP cases (3.5 % vs. 12.7 %, p?=?0.014). The LAP group had a significantly smaller incision length for specimen extraction (HALS (7.0?±?1.3 cm) vs. LAP (5.7?±?2.1 cm), p?<?0.001). Length of stay, operative time, morbidity, and mortality rates were comparable between the two groups.

Conclusion

In obese patients who require colectomy, the HALS approach increases the likelihood of a successful minimally invasive operation. At the cost of a clinically negligible increase in incision length, HALS may save a high-risk group conversion to formal laparotomy and the adverse outcomes related to this.     

Bedside score predicting retained common bile duct stone in acute biliary pancreatitis

BACKGROUND Retained common bile duct(CBD) stone after an acute episode of biliary pancreatitis is of paramount importance since stone extraction is mandatory.AIM To generate a simple non-invasive score to predict the presence of CBD stone in patients with biliary pancreatitis.METHODS We performed a retrospective study including patients with a diagnosis of biliary pancreatitis. One hundred and fifty-four patients were included. Thirty-three patients(21.5%) were diagnosed with CBD stone by endoscopic ultrasound(US).RESULTS In univariate analysis, age(OR: 1.048, P = 0.0004), aspartate transaminase(OR:1.002, P = 0.0015), alkaline phosphatase(OR: 1.005, P = 0.0005), gamma-glutamyl transferase(OR: 1.003, P = 0.0002) and CBD width by US(OR: 1.187, P = 0.0445)were associated with CBD stone. In multivariate analysis, three parameters were identified to predict CBD stone;age(OR: 1.062, P = 0.0005), gamma-glutamyl transferase level(OR: 1.003, P = 0.0003) and dilated CBD(OR: 3.685, P = 0.027),with area under the curve of 0.8433. We developed a diagnostic score that included the three significant parameters on multivariate analysis, with assignment of weights for each variable according to the co-efficient estimate. A score that ranges from 51.28 to 73.7 has a very high specificity(90%-100%) for CBD stones, while a low score that ranges from 9.16 to 41.04 has a high sensitivity(82%-100%). By performing internal validation, the negative predictive value of the low score group was 93%.CONCLUSION We recommend incorporating this score as an aid for stratifying patients with acute biliary pancreatitis into low or high probability for the presence of CBD stone.     

Characteristics of Suture Materials Used in Oral Surgery: Systematic Review

BackgroundThe aim of this review was to evaluate the most used suture materials with regards to their inflammatory response, their bacterial adhesion, and their physical properties when used to close oral wounds.MethodsFour databases (PubMed, Scopus, Dentistry & Oral Sciences, and OVID) were searched to retrieve relevant studies from January 1, 2000, to January 31, 2020.ResultsOut of the 269 articles, only 13 studies were selected as they were relevant and met the systematic review's protocol. These studies showed that almost all suture materials studies (catgut, polyglycolic acid [PGA] sutures, nylon, expanded polytetrafluoroethylene, and silk sutures) caused bacterial adherence and tissue reaction. In nylon and chromic catgut, the number of bacteria accumulated was lowest. Silk and nylon were found to be more impacted than catgut and PGA in terms of physical characteristics such as tensile strength. PGA, on the other hand, was said to be the most susceptible to knot unwinding.ConclusionsFollowing an oral surgical operation, all sutures revealed varied degrees of irritation and microbial accumulation. Nonresorbable monofilament synthetic sutures, however, exhibited less tissue response and less microbial accumulation.