Papers by Dhammika Dissanayake
Annals of Emergency Medicine, 2010
Study objective: Methemoglobinemia after pesticide poisoning is associated with a mortality of 12... more Study objective: Methemoglobinemia after pesticide poisoning is associated with a mortality of 12% in Sri Lanka. Treatment is complicated by the lack of laboratory facilities. We aimed to develop and validate a low-cost bedside test for quantitative estimation of clinically significant methemoglobin to be used in settings of limited resources. Methods: A method to reliably produce blood samples with 10% to 100% methemoglobin was developed. Freshly prepared methemoglobin samples were used to develop the color chart. One drop (10 L) of prepared methemoglobin sample was placed on white absorbent paper and scanned using a flatbed Cannon Scan LiDE 25 scanner. The mean red, green, and blue values were measured with ImageJ 1.37v. These color values were used to prepare a color chart to be used at the bedside. Interobserver agreement was assessed against prepared samples. The results from clinical use were compared with formal methemoglobin measurements. Results: The red color value was linearly related to percentage methemoglobin (R 2 ϭ0.9938), with no effect of absolute hemoglobin concentration. Mean interobserver (Nϭ21) agreement and weighted for scanned methemoglobin spots using the color chart were 94% and 0.83, respectively. Mean interobserver (Nϭ9) agreement and weighted for a freshly prepared methemoglobin sample with the chart were 88% and 0.71, respectively. Clinical use of the color chart also showed good agreement with spectrometric measurements. Conclusion: A color chart can be used to give a clinically useful quantitative estimate of methemoglobinemia.
Copyright © 2015 Kithsiri Bandara Jayasekara et al. This is an open access article distributed un... more Copyright © 2015 Kithsiri Bandara Jayasekara et al. This is an open access article distributed under the terms of Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Background: The aim of the study was to identify the epidemiology of chronic kidney disease of uncertain etiology in Sri Lanka. Methods: A cross-sectional study was carried out by analyzing health statistics, and three cohort studies were conducted (n = 15 630, 3996, and 2809) to analyze the demographic information, age-specific prevalence, etiology, and stage of presentation. We screened 7604 individuals for chronic kidney disease of uncertain etiology. Results: The results showed that the male:female ratio was 2.4:1, the mean age of patients was 54.7 ± 8 years, 92% of the patients were farmers, and 93 % consumed water from shallow dug wells. Familial occurrence was common (36%). The prevalence of chron...
Journal of Clinical Laboratory Analysis, 2011
Methemoglobin (MetHb) is a significant clinical problem for some poisonings. Its measurement is a... more Methemoglobin (MetHb) is a significant clinical problem for some poisonings. Its measurement is a problem as both formation and reduction of MetHb can occur even after sampling with time. The objective of this study was to discover a method to stabilize the blood samples for the determination of MetHb. First, hemolysates were prepared by diluting the MetHb blood samples with phosphate buffers under different pH values. The samples were stored at 4-81C and a day-today variability in the amount of MetHb was determined using the method described by Evelyn and Malloy. The results show that there is a significant
British Journal of Haematology, 1994
Serum thymidine kinase (TK) was determined in a family with congenital dyserythropoietic anaemia ... more Serum thymidine kinase (TK) was determined in a family with congenital dyserythropoietic anaemia type 111 (CDA, type 111). 20 patients and 10 of their healthy siblings were investigated. Elevated TK was found in all 20 patients (median 56.2 U) but their healthy siblings had normal values (median 2.6 5 U). We suggest that determination of TK should be used for discrimination between healthy siblings and individuals affected by CDA type I11 when bone marrow examination is not suitable.
British Journal of Haematology, 1994
Serum thymidine kinase (TK) was determined in a family with congenital dyserythropoietic anaemia ... more Serum thymidine kinase (TK) was determined in a family with congenital dyserythropoietic anaemia type 111 (CDA, type 111). 20 patients and 10 of their healthy siblings were investigated. Elevated TK was found in all 20 patients (median 56.2 U) but their healthy siblings had normal values (median 2.6 5 U). We suggest that determination of TK should be used for discrimination between healthy siblings and individuals affected by CDA type I11 when bone marrow examination is not suitable.
Clinical Toxicology, 2010
Background. Despite a significant increase in the number of patients with paracetamol poisoning i... more Background. Despite a significant increase in the number of patients with paracetamol poisoning in the developing world, plasma paracetamol assays are not widely available. The purpose of this study was to assess a low-cost modified colorimetric paracetamol assay that has the potential to be performed in small laboratories with restricted resources. Methods. The paracetamol assay used in this study was based on the Glynn and Kendal colorimetric method with a few modifications to decrease the production of nitrous gas and thereby reduce infrastructure costs. Preliminary validation studies were performed using spiked aqueous samples with known concentrations of paracetamol. Subsequently, the results from the colorimetric method for 114 stored clinical samples from patients with paracetamol poisoning were compared with those from the current gold-standard high-performance liquid chromatography method. A prospective survey, assessing the clinical use of the paracetamol assay, was performed on all patients with paracetamol poisoning attending the Peradeniya General Hospital, Sri Lanka, over a 10-month period. Results. The recovery study showed an excellent correlation (r 2 > 0.998) for paracetamol concentrations from 25 to 400 mg/L. The final yellow color was stable for at least 10 min at room temperature. There was also excellent correlation with the high-performance liquid chromatography method (r 2 = 0.9758). In the clinical cohort study, use of the antidote N-acetylcysteine was avoided in over a third of patients who had the plasma paracetamol concentration measured. The cost of consumables used per assay was $0.50 (US). Conclusions. This colorimetric paracetamol assay is reliable and accurate and can be performed rapidly, easily, and economically. Use of this assay in resourcepoor clinical settings has the potential to have a significant clinical and economic impact on the management of paracetamol poisoning.
Effects of four species of interferon-alpha on cultured erythroid progenitors from congenital dyserythropoietic anaemia type I
British Journal of Haematology, 1998
The in vitro effects of interferon (IFN)-alpha on erythroid progenitor cells derived from the per... more The in vitro effects of interferon (IFN)-alpha on erythroid progenitor cells derived from the peripheral blood of five patients with congenital dyserythropoietic anaemia (CDA) type I and seven healthy adults were studied. Ficol-hypaque-separated mononuclear cells were cultured for 14 d in StemGEM-1d medium with 0, 1, 10 and 100 U/ml of recombinant IFN-alpha2a, recombinant IFN-alpha2b, the genetically-engineered hybrid molecule IFN-alpha(1-8) or the laboratory-designed molecule IFN-alpha(consensus). Erythroid bursts and colonies were counted, picked and processed for electron microscopy. In the experiments employing IFN-alpha2a there were no differences in the numbers of erythroid bursts or colonies between four patients with CDA type I and seven healthy adults. All five patients with CDA type I showed the 'Swiss-cheese' ultrastructural abnormality of the heterochromatin in a proportion of the erythroblasts when the progenitor cells were cultured in the absence of added IFN-alpha. A statistically significant reduction in the proportion of erythroblasts showing the 'Swiss-cheese' defect was seen when the erythroid progenitors were cultured in the presence of 0.01-0.5 U/ml IFN-alpha2a (five patients), or 0.1 U/ml of IFN-alpha2b (two patients). In contrast, no reduction was seen in cultures containing 0.1-100 U/ml of either IFN-alpha(1-8) or IFN-alpha(consensus) or 20 microM hydroxyurea (two patients). The partial correction of the 'Swiss-cheese' abnormality by low concentrations of IFN-alpha2a in vitro provides an experimental model with which the mechanisms underlying the haematological response that occurs after the in vivo administration of this species of IFN-alpha may be investigated.
Cellular injury leading to oxidative stress in acute poisoning with potassium permanganate/oxalic acid, paraquat, and glyphosate surfactant herbicide
Environmental Toxicology and Pharmacology
PLOS Neglected Tropical Diseases
Background Acute kidney injury (AKI) is a major complication of snake envenoming, but early diagn... more Background Acute kidney injury (AKI) is a major complication of snake envenoming, but early diagnosis remains problematic. We aimed to investigate the time course of novel renal biomarkers in AKI following Russell's viper (Daboia russelii) bites. Methodology/Principal findings We recruited a cohort of patients with definite Russell's viper envenoming and collected serial blood and urine samples on admission (<4h post-bite), 4-8h, 8-16h, 16-24h, 1 month and 3 months post-bite. AKI stage (1-3) was defined using the Acute Kidney Injury Network criteria. AKI stages (1-3) were defined by the Acute Kidney Injury Network (AKIN) criteria. There were 65 Russell's viper envenomings and 49 developed AKI: 24 AKIN stage 1, 13 stage 2 and 12 stage 3. There was a significant correlation between venom concentrations and AKI stage (p = 0.007), and between AKI stage and six peak biomarker concentrations. Although most biomarker concentrations were elevated within 8h, no biomarker performed well in diagnosing AKI <4h post-bite. Three biomarkers were superior to serum creatinine (sCr) in predicting AKI (stage 2/3) 4-8h post-bite: serum cystatin C (sCysC) with an area under the receiver operating curve (AUC-ROC), 0.78 (95%CI:0.64-0.93), urine neutrophil gelatinase-associated lipocalin (uNGAL), 0.74 (95%CI:0.59-0.87) and urine clusterin (uClu), 0.81 (95%CI:0.69-0.93). No biomarker was better than sCr after 8h. Six other urine biomarkers urine albumin, urine beta2-microglobulin, urine kidney injury molecule-1, urine
Malaysian Journal of Medical Sciences
Background: Chronic kidney disease of uncertain aetiology (CKDu) is one of the major health conce... more Background: Chronic kidney disease of uncertain aetiology (CKDu) is one of the major health concerns among agricultural communities in Sri Lanka. Individuals involved in severe agricultural works for their livelihood are highly vulnerable for this disease and patients have been detected with persisting proteinuria at community-level screening. The current study was designed to evaluate the diagnosis of two functional markers of kidney damage using individuals with persisting proteinuria as the baseline. Methods: One hundred and fifty hard-working agricultural farmers from high-prevalence area for CKDu (Madawachchiya) were screened three times for proteinuria; 66 proteinuric and 21 non-proteinuric were identified as the baseline classification. Selected individuals were analysed further for creatinine, protein and cystatin C in urine and creatinine, cystatin C in serum. Urine protein-to-creatinine ratio (UP/UC) was calculated. Results: Based on creatinine and cystatin C cutoff levels in serum, individuals were classified as high or normal. Diagnosis of two functional markers (creatinine and cystatin C) were evaluated using receiver operating characteristic (ROC) curve and in terms of sensitivity and specificity using UP/UC as the baseline. Creatinine and cystatin C-based eGFR (estimated Glomerular filtration rate) levels were calculated, and Pearson's correlation coefficient was determined between different eGFR measurements using UP/UC. Mean (SD) UP/UC ratio, serum creatinine, and serum cystatin C levels of the proteinuric subjects were 129.0 (18.4) mg/mmol, 1.35 (0.39) mg/dL, 1.69 (0.58) mg/L. For non-proteniuric individuals, the results were found to be 14.4 (2.28), 1.22 (0.40) mg/dL, 0.82 (0.25) mg/L.
Journal of Diagnostic Pathology
The erythrocyte sedimentation rate (ESR) is one of the most common and traditional laboratory tes... more The erythrocyte sedimentation rate (ESR) is one of the most common and traditional laboratory tests in the world for detecting acute and chronic inflammation. This simple test has served as a nonspecific indicator of presence of disease. It also has been found useful in monitoring response to therapy, especially in rheumatologic disease. It reflects both plasma concentration of acute-phase proteins of large molecular size and anaemia. The ESR test is easy to perform and inexpensive, is used today as a routine test worldwide. However, the ESR has some demerits, in requiring large volume of sodium citrate or EDTA blood and at least 1 hr testing time. The minimum of 1 hr testing time is not practical for modernized laboratories. In this paper we investigated the possibility of using a rapid ESR test done on an inclined tube. We compared the results obtained by the rapid method and the traditional Westergren method of ESR using Pearson correlation. Blood samples from 153 patients with ESRs ranging from 1-165 were used for the study. Four ml of sodium citrate blood (3.2 ml of blood & 0.8ml of 3.8% of sodium citrate) is prepared and two Westergren tubes filled. Both tubes are mounted on two separate Westergren tube racks. After mounting, one ESR tube is tilted to an angle of 45 degrees from vertical and readings were taken at 4,
Performance of the 20-minute whole blood clotting test in detecting venom induced consumption coagulopathy from Russell's viper (Daboia russelii) bites
Thrombosis and haemostasis, Feb 28, 2017
The 20-minute whole blood clotting test (WBCT20) is used as a bedside diagnostic test for coagulo... more The 20-minute whole blood clotting test (WBCT20) is used as a bedside diagnostic test for coagulopathic snake envenoming. We aimed to assess the performance of the WBCT20 in diagnosis of venom induced consumption coagulopathy (VICC) in Russell's viper envenoming. Adult patients admitted with suspected snake bites were recruited from two hospitals. WBCT20 and prothrombin time (PT) test were performed on admission. WBCT20 was done by trained clinical research assistants using 1 ml whole blood in a 5 ml borosilicate glass tube with a 10 mm internal diameter. The PT was measured by a semi-automated coagulation system and international normalised ratio (INR) calculated. VICC was defined as present if the INR was >1.4. The diagnostic utility of WBCT20 was determined by calculating the sensitivity and specificity of the WBCT20 on admission for detecting VICC. There were 987 snake bites where both WBCT20 and PT were done on admission samples. This included 79 patients (8 %) with VICC...
BMC Pharmacology and Toxicology, 2016
Background: Sri Lanka has a high suicide rate, with more than 40 % of poisoning admissions due to... more Background: Sri Lanka has a high suicide rate, with more than 40 % of poisoning admissions due to overdose of drugs with Paracetamol being the commonest. Data regarding cardiotoxicity to paracetamol is very minimal though hepatotoxicity following poisoning is well studied. Paracetamol cardiotoxicity has rarely been clinically significant and may have well been overlooked. The possibility that paracetamol overdose might be directly cardiotoxic has been the subject of a few reports. Unexplained deaths and electrocardiographic changes associated with paracetamol poisoning have also been reported in which cardiac origin cannot be clearly ruled out. Although some studies state that paracetamol poisoning has no direct cardiotoxic effect, electrocardiographic changes due to metabolic derangement of hepatotoxicity have been shown in certain studies. Thus, we conducted this study to assess in detail the cardiotoxic effect of paracetamol poisoning. Methods: This is a cross sectional descriptive study done on those with confirmed paracetamol poisoning. Serum paracetamol levels, Electrocardiogram, Echocardiogram, troponin I, and other basic investigations were done. Results: Paracetamol ingestion is more common among teenagers and the young population in Sri Lanka. Although several cases of paracetamol poisoning induced cardiotoxicity has been described in the past, this study demonstrated no electrocardiographic, echocardiographic or cardiac biomarkers changes of myocardial toxicity. Conclusion: Though literature review support cardiotoxicity following paracetamol poisoning, our study does not provide enough evidence for this. Continuous cardiac monitoring, serial troponin and echocaediogram assessment would be voluble adjunct in its management. Further experiments and research in this subject would be useful with a larger number of samples to further evaluate this important problem.
A bedside test for methaemoglobinemia improved antidote use in propanil poisoning
Clinical Toxicology, 2016
In 2008, self-poisoning with the herbicide propanil had a case-fatality of around 11% in Sri Lank... more In 2008, self-poisoning with the herbicide propanil had a case-fatality of around 11% in Sri Lanka. A simple quantitative methaemoglobinemia bedside test was developed so that treatment could be titrated according to the methaemoglobin level. To determine whether the new method influenced patient management and changed the case fatality of propanil self-poisoning. The bedside test (using an inexpensive validated colour chart) was introduced in three hospitals (Anuradhapura, Polonnaruwa and Galle) in Sri Lanka from 2008. Junior ward staff were given a brief training on how to use the chart for quantitative estimation of methaemoglobin in patients with propanil poisoning and utilize the results in the context of the national treatment guidelines for propanil poisoning. It was taught that the bedside test should be done repeatedly from admission until it showed consistently low values of methaemoglobin. Treatment with the antidote methylene blue was suggested for patients whose methaemoglobin was greater than 20%. Limited clinical data on poisoning have been prospectively collected from these hospitals from 2003. The case-fatality and management before and after the change were compared with data up to December 2014. The case-fatality decreased from (38/401) 9.5% to (8/262) 3.1% [difference: -6.4%, 95% CI: -10 to -3]. Methylene blue use increased from under 10% of patients before to 55% of patients after the intervention. More patients received repeat doses and infusions, and few received ascorbic acid and exchange transfusion. The simple bedside test for methaemoglobinemia was readily adopted into routine practice and led to large changes in management. A substantial reduction in mortality from propanil poisoning occurred after this intervention.
The vitreous humour Potassium and Sodium concentration and time since death- preliminary findings of an ongoing study
Iron status and associated factors in theadolescents in Kandy district
Management of dental patients on anti platelet and anticoagulant therapy
The study was aimed to evaluate whether which spot urine protein to creatinine ratio (PC) can be ... more The study was aimed to evaluate whether which spot urine protein to creatinine ratio (PC) can be a reliable alternative to 24-hour urinary total protein (UTP) estimation by analyzing four day time spot urine samples of CKD clinic patients. We studied 48 CKD patients attending Nephrology unit with different nephritis such as diabetic nephropathy, CKD due to hypertension and unknown etiology (28male and 20 female) with proteinuria over 1g/day (GFR> 45 ml/min/1.73m 2) to determine the correlation between the measures of urine protein excretion by using four spot urine samples namely early morning,7am-10 am, 10am-4pm and before going to bed. The simple linear regression, central tendency and dispersion were calculated. The Friedman test was done to evaluate difference among urine protein levels of 4 day time urine samples. The mean 24 hour protein concentration was 3.8g/day+ 1.6 and the correlation coefficient (r) between 24-hour urine total protein and spot urine PC ratio were early morning 0.81 (P < 0.001), 7am-10 am 0.64 (P < 0.001), 10am-4pm 0.66 (P < 0.001) and before going to bed 0.792 (P < 0.001) in the study population. Early morning spot urine sample showed the highest linear association whereas the 7am-10am and 10am-4 pm shows lower associations compared to other two spot urine samples. Highest and lowest median of PC ratio were 7 am-10am and before going to bed respectively. Highest dispersion of PC ratio was observed in 10am-4 pm and the distribution of before bed is somewhat skewed to right. We conclude that the protein-tocreatinine ratio (PC) in early morning urine sample is an accurate, convenient, and reliable method to estimate the protein excretion in urine in study population in early stages of CKD.
ARTICLE INFO ABSTRACT The study was initiated with the objective to identify the role of G6PD def... more ARTICLE INFO ABSTRACT The study was initiated with the objective to identify the role of G6PD deficiency in chronic kidney disease patients with unknown etiology (CKD-U) in North Central Region (NCR) of Sri Lanka. 104 recently diagnosed, biopsy proven CKD-U patients (cases) and 208 age and sex matched controls were selected from same areas. Demographic information were collected and G6PD activities were determined in both cases and controls. The severity of G6PD deficiency was interpreted. Collected information were analyzed by using two-way ANOVA experimental design model and mean separation. The mean G6PD activity of the case group was significantly lower (p <0.001) than the control group. Twenty percent (20%) of the patients had G6PD deficiency whereas only 2% in control group. Smoking, histories of malaria, alcohol consumption were significantly contributed for the disease. Prevalence of G6PD deficiency was high among CKD-U patients and which may play a major role in the path...
Journal of Epidemiology, 2015
Background: The aim of the study was to identify the epidemiology of chronic kidney disease of un... more Background: The aim of the study was to identify the epidemiology of chronic kidney disease of uncertain etiology in Sri Lanka. Methods: A cross-sectional study was carried out by analyzing health statistics, and three cohort studies were conducted (n = 15 630, 3996, and 2809) to analyze the demographic information, age-specific prevalence, etiology, and stage of presentation. We screened 7604 individuals for chronic kidney disease of uncertain etiology. Results: The results showed that the male:female ratio was 2.4:1, the mean age of patients was 54.7 ± 8 years, 92% of the patients were farmers, and 93% consumed water from shallow dug wells. Familial occurrence was common (36%). The prevalence of chronic kidney disease in different age groups was 3% in those aged 30-40 years; 7% in those aged 41-50 years, 20% in those aged 51-60 years, and 29% in those older than 60 years. Chronic kidney disease of uncertain etiology was diagnosed in 70.2% of patients, while 15.7% and 9.6% were due to hypertension and diabetic mellitus, respectively. The majority of patients were stage 4 (40%) at first presentation, while 31.8% were stage 3 and 24.5% were stage 5. Stage 1 and 2 presentation accounted for only 3.4%. Conclusions: Low prevalence of CKDU was noticed (1.5%) among those who consumed water from natural springs. Prevalence was highest among males, rice farming communities, and those presenting at later disease stages.
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Papers by Dhammika Dissanayake