Geographic information system-based mapping of air pollution & emergency room visits of patients for acute respiratory symptoms in Delhi, India (March 2018-February 2019)

Background & objectives: Studies assessing the spatial and temporal association of ambient air pollution with emergency room visits of patients having acute respiratory symptoms in Delhi are lacking. Therefore, the present study explored the relationship between spatio-temporal variation of particulate matter (PM)2.5 concentrations and air quality index (AQI) with emergency room (ER) visits of patients having acute respiratory symptoms in Delhi using the geographic information system (GIS) approach. Methods: The daily number of ER visits of patients having acute respiratory symptoms (less than or equal to two weeks) was recorded from the ER of four hospitals of Delhi from March 2018 to February 2019. Daily outdoor PM2.5 concentrations and air quality index (AQI) were obtained from the Delhi Pollution Control Committee. Spatial distribution of patients with acute respiratory symptoms visiting ER, PM2.5 concentrations and AQI were mapped for three seasons of Delhi using ArcGIS software. Results: Of the 70,594 patients screened from ER, 18,063 eligible patients were enrolled in the study. Winter days had poor AQI compared to moderate and satisfactory AQI during summer and monsoon days, respectively. None of the days reported good AQI (<50). During winters, an increase in acute respiratory ER visits of patients was associated with higher PM2.5 concentrations in the highly polluted northwest region of Delhi. In contrast, a lower number of acute respiratory ER visits of patients were seen from the ‘moderately polluted’ south-west region of Delhi with relatively lower PM2.5 concentrations. Interpretation & conclusions: Acute respiratory ER visits of patients were related to regional PM2.5 concentrations and AQI that differed during the three seasons of Delhi. The present study providessupport for identifying the hotspots and implementation of focused, intensive decentralized strategies to control ambient air pollution in worst-affected areas, in addition to the general city-wise strategies.

Establishing a normal reference range for thromboelastography in North Indian healthy volunteers.

Background: Thromboelastography (TEG) is relatively recent assay to analyze the coagulation state of a blood sample, providing a continuous visualization of physical changes occurring during blood coagulation. There is a paucity of published literature on assessment of coagulation status using TEG in Indian population. Aim: The primary aim of the following study is to establish normal reference values for TEG in North Indian healthy volunteers and secondary aim is to compare them with conventional plasma-based routine coagulation tests and the manufacturers reference range. Materials and Methods: A total of 200 healthy volunteers comprised of 100 males and 100 females of age groups between 20 and 50 years, were enrolled over a period of 1 year, i.e., 2011-2012. Thromboelastometry (TEM) was performed on TEM-A automated thromboelastometer (Framar Biomedica, Rome, Italy), using whole blood non-additive (360 μl). TEG parameters analyzed were r-time, k-time, α-angle, maximal amplitude (MA). Prothrombin time (PT), activated partial thromboplastin time (aPTT) and platelet count was performed for all volunteers. The 95% reference range was calculated as (mean-1.96 standard deviation [SD]) to (mean + 1.96 SD). Results: Our reference values for 95% of 200 volunteers were r-time: 1.8-14.2 min, k-time: 0.7-7.3 min, α-angle: 27.3-72.3° and MA: 32.1-87.9 mm. Maximum clot strength was higher in women compared with men, however statistically insignifi cant. Overall 14.5% (29/200) of the volunteers had at least one abnormal parameter while 74% (149/200) had deranged TEG values using the manufacturer’s reference range. Statistically signifi cant variation was seen in r-time for 84.8% (P < 0.001), for k-time, in 87.1% (P < 0.001), for α-angle in 83.7% (P < 0.001) and for MA in 84% (P < 0.001), between the manufacturer and our reference range. Conclusion: The effi cacy of classical coagulation test has been well-established; on the contrary TEG is a fairly recent assay and its utility for patient management remains to be demonstrated. We observed TEG to be oversensitive in determining coagulopathy where there is no clinical presentation. The manufacturer’s reference values may not be appropriate for different ethnicity. TEG may give an overall representation of hemostasis; however, it cannot replace the conventional coagulation tests. We recommend the determination of normal TEG values by each laboratory for their target population.

A pilot study for diagnosis of genital Chlamydia trachomatis infections by polymerase chain reaction among symptomatic Indian women.

Background: Chlamydia trachomatis is the most common bacterial etiology of sexually transmitted infection. Aim : A pilot study was designed using PCR for amplification and detection of a specific 517 bp sequence of the common endogenous plasmid of C. trachomatis from clinical swab specimens obtained from symptomatic female patients attending STD clinics of AIIMS and Regional STD Teaching, Training & Research Center, Safdarjang Hospital, New Delhi. Methods: 97 patients were recruited in the study, and endocervical swabs were collected following standard procedures. The samples were analyzed by PCR and direct fluorescence antibody (DFA) for detection of C. trachomatis, and the sensitivity, specificity, PPV and NPV of PCR were calculated taking DFA as gold standard. Results: Out of 97 samples tested, 9 were positive for C. trachomatis by PCR. 1 PCR positive patient was negative by DFA although a total of 11 patients were positive by DFA. The sensitivity, specificity, PPV and NPV of PCR with reference to DFA was 72.73%, 98.84%, 88.89% and 96.59%, respectively. This PCR had high specificity and NPV for detection of C.trachomatis. Conclusions : In light of the introduction of enhanced syndromic approach, which involves the use of laboratory techniques (wherever possible) to confirm clinical diagnosis, a diagnostic PCR with high specificity and NPV is particularly valuable for determination of etiological diagnosis and hence contribute to judicious use of antimicrobials in the community.

Evaluation of an automated erythrocyte sedimentation rate analyzer as compared to the Westergren manual method in measurement of erythrocyte sedimentation rate.

Context: Monitor 100® (Electa Lab, Italy) is a newly developed automated method for measurement of erythrocyte sedimentation rate (ESR). Aims: The aim of our study was to compare the ESR values by Monitor 100® against the standard Westergren method. Patients and Methods: This cross-sectional study was conducted at a Level I trauma care center on 200 patients. The samples taken were as per the recommendations charted out by International Council for Standardization in Hematology (ICSH) for comparing automated and manual Westergrens method. Statistical Analysis Used: Bland and Altman statistical analysis was applied for evaluating Monitor 100® against the conventional Westergren method. Results: The analysis revealed a low degree of agreement between the manual and automated methods especially for higher ESR values, mean difference -11.2 (95% limits of agreement, -46.3 to 23.9) and mean difference -13.4 (95% limits of agreement-58.9 to 32.1) for 1 and 2 hours, respectively. This discrepancy which is of clinical significance was less evident for ESR values in the normal range <25 mm/hour (-7.7 mean of difference; -18.9 to 3.5 limits of agreement). Conclusions: The fully automated system Monitor 100® for ESR measurement tends to underestimate the manual ESR readings. Hence it is recommended that a correction factor be applied for the range of ESR values while using this equipment. Further studies and validation experiments would be required.

Normal Values of Liver and Spleen Size by Ultrasonography in Indian Children.

Objectives: To establish normative data for the ultrasonographic measurement of liver and spleen size in healthy Indian children. Setting: Tertiary-care pediatric teaching hospital. Design: Cross-sectional, hospital-based study. Participants: 597 healthy children between the ages of 1 month to 12 years. Measurements: Ultrasonographic evaluation for the assessment of liver and spleen size. These were correlated with the age, sex, height/length and weight of the participants. Results: Normal liver and spleen length and range were obtained sonographically. The liver and spleen length significantly correlated highly with the height/length of the subjects (P=0.0001). Conclusions: The study provides the normal values of liver and spleen size by ultrasonography in healthy Indian children.

Proton magnetic resonance spectroscopy of brain to study the cerebral metabolic abnormalities in COPD patients: a case control study in north India.

BACKGROUND: To investigate changes in the cerebral metabolism of nondiabetic and normolipidaemic patients with chronic obstructive pulmonary disease (COPD) using localised in vivo proton magnetic resonance spectroscopy (1H MRS), and to correlate these with the severity of disease. METHODS: Twenty-eight symptomatic COPD patients and 19 healthy controls underwent 1H MRS of brain, pulmonary function testing and respiratory muscle strength evaluation. The parieto-temporal and occipital regions were localised for 1H MRS. The metabolic ratios of N-acetyl aspartate to cretinine (NAA/Cr) and choline containing compound to creatinine (Cho/Cr) were calculated by integrating area under the each peak. RESULTS: The mean value of NAA/Cr and Cho/Cr in parieto-temporal area in COPD patients were (1.86 +/- 0.54) and (0.77 +/- 0.23), respectively. The mean values of NAA/Cr and Cho/Cr in occipital area in COPD patients were (1.75 +/- 0.44) and (0.61 +/- 0.25), respectively. Compared with healthy control subjects, the mean values of Cho/Cr in COPD patients were lower, both in parieto-temporal (0.77 +/- 0.23 vs. 0.89 +/- 0.35; p = 0.17) and occipital (0.61 +/- 0.25 +/- vs. 0.67 +/- 0.08; p = 0.36) areas of the brain. CONCLUSIONS: The cerebral metabolism, pulmonary function testing and respiratory muscle strength altered in symptomatic COPD patients. The clinical significance of cerebral metabolic changes in COPD patients needs to be further investigated.

Centbucridine, a newer topical anaesthetic compared with lignocaine: a randomized double masked single drop instillation clinical trial.

A randomized double-masked single drop instillation clinical trial was conducted on 60 healthy volunteers divided into 3 equal groups to compare the efficacies of centbucridine and lignocaine. One eye of each volunteer was instilled with a single drop of either 0.5% centbucridine hydrochloride, 1% centbucridine hydrochloride or 4% lignocaine hydrochloride, with the other eye as an unanaesthetized control-side effects, if any, were also recorded. The onset of anaesthesia assessed both objectively and subjectively, was quickest with lignocaine 4% (P < 0.001) followed by centbucridine 0.5% and 1%. However, the period of peak activity as well as the total duration of surface anaesthesia, and also the depth of analgesia, were significantly highest with 1% centbucridine, followed by 0.5% centbucridine and 4% lignocaine respectively. Minor side effects like burning sensations were longest with 1% centbucridine--no significant adverse effects, local or systemic, were observed. Prolonged surface anaesthetic and analgesic actions of centbucridine 1% may be advantages for longer duration ophthalmic microsurgeries.