Topical heparin or antivenom therapy significantly improved overall outcomes in rabbit corneas exposed to Naja sumatrana venom, compared to tetracycline, dexamethasone and controls. Heparin treatment remains efficacious up to 4 minutes delay.

Mechanical ventilation (MV) during exacerbation of asthma or chronic obstructive pulmonary disease (COPD) is unequivocally needed when apnoea, cardiorespiratory arrest, coma, hypoxia or treatment failure is present. The need is less clear when the patient can respond, has intact airway reflexes and spontaneous respiration. In this situation, acidosis is an important factor in the decision to institute MV. This study aimed to provide a clinical means of identifying patients with acute respiratory acidosis (ARA) in a setting where blood gas analysis is unavailable. We undertook a prospective, observational study of consecutive patients who presented to two emergency departments with severe and life-threatening exacerbation of asthma or COPD. Each underwent clinical assessment, treatment and blood gas analysis. The outcome measure was ARA or mixed ARA and metabolic acidosis. A total of 127 episodes in patients aged 15-90 years (65.3% males and 34.7% females) were included in the study. Of these, 62.2% had asthma and 37.8% had COPD; 71.7% had life-threatening and 28.3% had severe attacks. Overall, the adjusted odds ratio (and 95% confidence intervals) for predictors of ARA were 7.09 (1.79-28.06) for drowsiness, 4.11 (1.31-12.88) for flushing, 3.34 (1.01-11.02) for having COPD and 2.86 (1.01-8.07) for intercostal retractions. In conclusion, with drowsiness, the likelihood of ARA is about seven times higher. The presence of flushing, COPD and intercostal retractions also increase the risk of ARA.

Introduction: Routine blood cultures have been recommended for all patients in treatment guidelines for community-acquired pneumonia (CAP). This practice has become a major area of resource utilisation, despite the lack of evidence in its clinical utility. Calls for abandoning the practice is balanced by the occasions of uncovering an unexpected pathogen or an unusual antimicrobial resistance pattern. The aim of this study is to identify factors that predict positive blood cultures among patients hospitalised for pneumonia upon presentation at the Emergency Department (ED). Materials and Methods: A case control study was carried out on patients treated for pneumonia in the ED who had routine blood cultures performed as part of their management. The pneumonia severity index (PSI) was used to categorise patients into low- and high-risk for 30-day mortality. Logistic regression was carried out to determine factors significantly associated with positive blood cultures, from which a predictive probability equation was used to identify patients whose blood cultures were negative at a pre-determined cut-off, with minimum number of culture positive misclassification. A scoring system was devised, with scores predicting which patients would be likely to have a positive or negative blood culture. Results: A total of 1407 patients with pneumonia were treated at ED from May to December 2006, from whom 1800 blood cultures were performed. Of these, 140 cultures (7.8%) grew organisms, comprising 96 (5.3%) true positive cultures and 44 (2.4%) contaminated cultures. Logistic regression analysis identified ill patients with higher PSI classes, smokers and Malay patients to be more likely to have positive blood cultures. Patients who had prior treatment with antibiotics, chronic obstructive pulmonary disease and cough were less likely to have positive blood cultures. An index to predict a negative blood culture resulted in the accurate classification of all but 4 positive patients while still correctly classifying 27.8% of blood culture negative patients. The area under the ROC curve was 0.71 (95% CI, 0.65-0.76). A simplified scoring system was devised based on the predictive model had a sensitivity of 82% and specificity of 38.2% for a positive blood culture. Conclusion: Routine blood cultures yielded negative results in 94% of patients presenting with pneumonia. The development of the clinical scoring system is a first step towards selecting patients for whom blood cultures is performed and improve cost-effectiveness. Introduction: Routine blood cultures have been recommended for all patients in treatment guidelines for community-acquired pneumonia (CAP). This practice has become a major area of resource utilisation, despite the lack of evidence in its clinical utility. Calls for abandoning the practice is balanced by the occasions of uncovering an unexpected pathogen or an unusual antimicrobial resistance pattern. The aim of this study is to identify factors that predict positive blood cultures among patients hospitalised for pneumonia upon presentation at the Emergency Department (ED). Materials and Methods: A case control study was carried out on patients treated for pneumonia in the ED who had routine blood cultures performed as part of their management. The pneumonia severity index (PSI) was used to categorise patients into low- and high-risk for 30-day mortality. Logistic regression was carried out to determine factors significantly associated with positive blood cultures, from which a predictive probability equation was used to identify patients whose blood cultures were negative at a pre-determined cut-off, with minimum number of culture positive misclassification. A scoring system was devised, with scores predicting which patients would be likely to have a positive or negative blood culture. Results: A total of 1407 patients with pneumonia were treated at ED from May to December 2006, from whom 1800 blood cultures were performed. Of these, 140 cultures (7.8%) grew organisms, comprising 96 (5.3%) true positive cultures and 44 (2.4%) contaminated cultures. Logistic regression analysis identified ill patients with higher PSI classes, smokers and Malay patients to be more likely to have positive blood cultures. Patients who had prior treatment with antibiotics, chronic obstructive pulmonary disease and cough were less likely to have positive blood cultures. An index to predict a negative blood culture resulted in the accurate classification of all but 4 positive patients while still correctly classifying 27.8% of blood culture negative patients. The area under the ROC curve was 0.71 (95% CI, 0.65-0.76). A simplified scoring system was devised based on the predictive model had a sensitivity of 82% and specificity of 38.2% for a positive blood culture. Conclusion: Routine blood cultures yielded negative results in 94% of patients presenting with pneumonia. The development of the clinical scoring system is a first step towards selecting patients for whom blood cultures is performed and improve cost-effectiveness.

No abstract

Naja sumatrana is the dominant cobra species in Malaysia, Singapore, Borneo, and Sumatra, and it does not have specific antivenom. The Haffkine antivenom has been advocated instead. This study aims to determine the efficacy of this antivenom against Naja sumatrana envenoming using a mouse model. Methods. Male Swiss albino mice were used. Intravenous LD50 was first determined separately for Naja naja and Naja sumatrana venom. ED50 was determined by preincubating antivenom with each venom at 2.5 LD50 before administering the mixture into the tail vein. Validation was carried out using a challenge test. Each mouse received 111 µg of Naja sumatrana venom intramuscularly followed by intraperitoneal administration of dilute Haffkine antivenom. Survival was recorded 24 hours after envenoming. Results. The LD50 of Naja naja venom was 78.13 µg, standard error (SE) 13.3 µg. The ED50 of the Haffkine antivenom against Naja naja venom was 45.9 mg, SE 7.5 mg. The LD50 and ED50 of Naja sumatrana venom were 55.5 µg, SE 12.0 µg; and 73.9 mg, SE 12.0 mg, respectively. The intra-peritoneal ED50 against 111 µg intramuscular Naja sumatrana venom was 136.95 mg, SE 36.74 mg. Conclusion. The Haffkine polyvalent antivenom exhibited cross-neutralisation against Naja sumatrana venom when used at a higher dose.