Correlation of refractory hypoxemia with biochemical markers and clinical outcomes of COVID-19 patients in a developing country: A retrospective observational study: Running head: Predictors of hypoxemia in COVID-19.

INTRODUCTION: COVID-19 is mainly a respiratory illness, causing hypoxemia in the majority of those been infected. In our study, we aimed to correlate the biochemical markers with hypoxemia and predicting the prognosis of COVID-19 patients. MATERIALS AND METHODS: A retrospective, observational study was conducted to include all the admitted COVID-19 patients (n = 183) diagnosed by a real-time Polymerase chain reaction and evaluated those for hypoxemia and disease outcomes by utilizing the biochemical markers. RESULTS: Out of the 183 patients, 117 were in the ward, 66 were in ICU, 148 of them recovered, while 35 deaths were reported, 89 patients were having persisting hypoxemia (despite oxygen therapy) during the hospital stay, and the remaining 94 were non-hypoxemic with or without supplemental oxygen therapy. There were significant differences in mean hemoglobin (p = 0.028), total leukocyte count (p = 0.005), Neutrophil-to-Lymphocyte ratio (p = 0.001), serum urea and creatinine (p = 0.002), serum potassium (p = 0.009), C-reactive protein (p = 0.001), Lactate dehydrogenase (p = 0.005), and Ferritin (p = 0.042) of the hypoxemic patients versus non-hypoxemic group. Amongst the deceased patients, there was significant leukocytosis (p = 0.008), increased Neutrophil-to-Lymphocyte ratio (p = 0.001), elevated C-reactive protein (p = 0.001), and Lactate dehydrogenase (p = 0.009). Receiver operating characteristic curves showed Neutrophil-to-Lymphocyte ratio (p < 0.001), C-reactive protein (p < 0.001), and Lactate dehydrogenase (p < 0.001) most significantly associated with hypoxemia and death. CONCLUSION: The inflammatory markers are a good guide for predicting the hypoxemia and disease outcome. The results concluded Neutrophil-to-Lymphocyte ratio, C-reactive protein, and Lactate dehydrogenase were effective biomarkers in predicting a severe course of COVID-19, but could not establish significant associations of serum Ferritin, Procalcitonin, and D-Dimer.

Acute appendicitis: diagnostic accuracy of Alvarado scoring system.

OBJECTIVE: To evaluate the usefulness of the Alvarado scoring system in reducing the percentage of negative appendectomy in our unit. MATERIALS AND METHODS: A cross-sectional study was conducted, comprising 110 patients, admitted to Surgical Unit I, Civil Hospital, Karachi, in 2011 with a preliminary diagnosis of acute appendicitis. Patients of both sexes and all age groups except younger than 10 years were included in the study and their Alvarado scores calculated, on the basis of which patients were divided into two groups: Group A (Alvarado score <6) and Group B (Alvarado score ≥6). The signs, symptoms, laboratory values, surgical interventions, and pathology reports of each patient were evaluated. Diagnosis was confirmed by histopathological examination. Sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: Out of 110 cases (79 males, 31 females), 31 belonged to Group A (28.2%) and 79 belonged to Group B (71.8%). Surgical procedures were performed in 98.2% of cases, along with conservative treatment. Final diagnosis by histopathology was confirmed in 77 cases (71.3%). The overall negative appendectomy rate was 28.7% (males: 28.2%, females: 30%). Sensitivity and specificity of the Alvarado scoring system were found to be 93.5% and 80.6% respectively. Positive and negative predictive values were 92.3% and 83.3%, respectively, and accuracy was 89.8%. CONCLUSION: Alvarado score can be used effectively in our setup to reduce the incidence of negative appendectomies. However, its role in females was not satisfactory and needs to be supplemented by other means.

Enteric fever in Karachi: current antibiotic susceptibility of Salmonellae isolates.

OBJECTIVE: To determine the current sensitivity and resistance profile of Salmonellae (S.) isolates in a laboratory setting. STUDY DESIGN: An observational study. PLACE AND DURATION OF STUDY: Dr. Essa`s Laboratory and Diagnostic Centre, Karachi, Pakistan, from November 2008 - October 2010. METHODOLOGY: Isolates from blood culture specimens of 481 bacteraemic patients were identified using conventional biochemical tests. Salmonellae was confirmed with specific antisera and their antibiograms determined by Kirby-Bauer Disc Diffusion method using 12 relevant antibiotics. Inclusions of the study were bacteraemia documented in all blood samples positive for S. typhi, S. paratyphi-A and B. Exclusions were all samples other than blood and blood samples negative for S. typhi and S. paratyphi-A and B during the same period. Multidrug resistance (MDR) of isolates was defined as the isolates showing resistance to all conventional anti-typhoid medicines i.e., Chloramphenicol, Ampicillin and Co-trimoxazole. RESULTS: Specimens (n=217) yielded 131 Salmonellae typhi (60.36%), 71 S. paratyphi-A (32.71%), and 15 S. paratyphi-B (6.9%); these were sensitive to the Quinolones [Enoxacin: 94.96% (n=91), Ciprofloxacin, 96.47% (n=182), Ofloxacin: 95.74% (n=203)], and Cephalosporins [Cefixime: 96.62% (n=202), Cefotaxime: 99.17% (n=206), Ceftriaxone: 98.79% (n=208)]. Resistance to Amoxicillin was 96.48% (n=128) and 29.91% (n=78) to Co-trimoxazole. About 62.64% (n=136) of the isolates were MDR strains. CONCLUSION: Ciprofloxacin is currently a suitable empirical choice in presumed enteric fever cases, but culture and sensitivity analysis should be encouraged and results incorporated in prescription strategy. Increasing frequency of S. paratyphi-A isolates possibly suggests incomplete coverage employing monovalent vaccine.