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Introduction Peritonitis refers to the inflammation of the peritoneum and peritoneal cavity. Causes of peritonitis can be bacterial (gastrointestinal or non-gastrointestinal), chemical, traumatic, or ischemic. Peritonitis can be localized or diffuse, acute or chronic. Peritonitis can be primary, secondary, or tertiary, according to the pathogenesis. Peritonitis developed secondary to hollow viscus perforation is a life-threatening condition and a common cause of emergency surgery in India. The Mannheim peritonitis index (MPI) is a simple scoring system that can accurately predict the outcome of peritonitis. This study aimed to evaluate the effectiveness of MPI in predicting mortality risk or prognosis in patients with peritonitis due to hollow viscus perforation. Materials and methods This observational cross-sectional study at the Department of General Surgery, Rajendra Institute of Medical Sciences, Ranchi, involved 111 patients with peritonitis due to hollow viscus perforation from December 2021 to March 2022. Detailed history, clinical examination, relevant blood tests, and radiological investigations established a diagnosis of perforation peritonitis, followed by a score assessment. Data were analyzed using SPSS software (IBM Corp., Armonk, NY, USA). Results Patients >50 years had higher mortality (i.e., 18/43) than patients <50 years (i.e., 13/68). Overall mortality was 31, which included one in low risk, 12 in intermediate risk, and 18 in the high-risk group. Mortality was lowest in the low-risk group (i.e., 1/30), highest in the high-risk group (i.e., 18/40), and 12/41 in the intermediate-risk group; the p-value was <0.05, which was highly significant. Mortality was higher in patients presenting after 24 hours, having organ failure, and non-colonic sepsis. Conclusion The MPI scoring system is simple, easy to calculate, cost-effective, precise, and effective in assessing mortality and morbidity risk in patients with peritonitis due to hollow viscus perforation. It can also guide further management strategies.
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PURPOSE: To determine if the same object frequency information mediates letter contrast threshold in the presence and absence of additive luminance noise (i.e., "noise-invariant processing") for letters of different size. METHODS: Contrast thresholds for Sloan letters ranging in size from 0.9 to 1.8 log MAR were obtained from three visually normal observers under three paradigms: (1) high- and low-pass Gaussian filtered letters were presented against a uniform adapting field; (2) high- and low-pass Gaussian filtered letters were presented in additive white luminance noise; and (3) unfiltered letters were presented in high- and low-pass Gaussian filtered luminance noise. A range of high- and low-pass filter cutoffs were used to limit selectively the object frequency content of the letters (paradigms 1 and 2) or noise (paradigm 3). The object frequencies mediating letter identification under each paradigm were derived from plots of log contrast threshold vs. log filter cutoff frequency. RESULTS: The object frequency band mediating letter identification systematically shifted to higher frequencies with increasing log MAR letter size under all three paradigms. However, the relationship between object frequency and letter size depended on the paradigm under which the measurements were obtained. The largest difference in object frequency among the paradigms was observed at 1.8 log MAR, where the addition of white noise nearly doubled the center frequency of the band of object frequencies mediating letter identification, compared to measurements made in the absence of noise. CONCLUSION: Noise can affect the object frequency band mediating letter contrast threshold, particularly for large letters, an effect that is likely due to strong masking of the low frequency letter components by low frequency noise checks. This finding indicates that noise-invariant processing cannot necessarily be assumed for large letters presented in white noise.
