Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien–Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk.

A 66-year-old male patient presented with decreased vision in both eyes following episode of Chikungunya fever. Examination revealed bilateral retinal lesions with stippled pigmentary changes at the level of the choriocapillaris, involving the macula in the left eye. The retinopathy consisted of outer retinal disruption and retinochoroidal flow abnormalities detected using with additional imaging, including spectral-domain optical coherence tomography (OCT), autofluorescence, and OCT angiography (OCTA). The index case report describes unique OCTA findings in both eyes of an elderly male secondary to Chikungunya fever. Using the technique of OCTA, insights into the mechanisms of visual damage in viral retinopathies such as Chikungunya fever can be understood.

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Orthogonal Frequency Division Multiplexing is a wideband modulation scheme that is designed to cope with the problems of the multipath reception. Essentially, the wideband frequency selective fading channel is divided into many narrow-band sub channels. There has been greatly increasing interest in orthogonal frequency division multiplexing for broadband wireless transmission due to its robustness against multipath fading. In this article, by extensive computer simulation, we present a comprehensive performance comparison of OFDM-based schemes in a nonlinear and frequency-selective fading channel. In this paper design of OFDM system transmitter and receiver using frequency selective fading is introduced and to know the behavior we have done the simulation using MATLAB.