Brain Imaging in Cases with Positive Serology for Dengue with Neurologic Symptoms: A Clinicoradiologic Correlation.

BACKGROUND AND PURPOSE: Dengue is a common arboviral disease, which uncommonly involves the brain. There has been a recent surge in dengue cases and dengue-related deaths in tropical countries. The aim of this study was to describe brain imaging findings in patients with dengue infection having neurologic symptoms. MATERIALS AND METHODS: Thirty-five patients with positive serology for dengue with CNS symptoms undergoing imaging of the brain were included in the study. Clinical, laboratory, and imaging parameters were assessed and correlated to poor outcome. RESULTS: A Glasgow Coma Scale score of ≤12 at presentation, clinical classification of severe-type dengue, and the presence of acute renal failure were associated with poor outcome. Imaging parameters associated with poor outcome were involvement of the thalami and cerebellar peduncles and the presence of diffusion restriction and hemorrhagic foci in the brain parenchyma. CONCLUSIONS: Although not specific, dengue infection has imaging findings that can be used to narrow down the differential list and help in prognostication.

Organophosphate-pyrethroid combination pesticides may be associated with increased toxicity in human poisoning compared to either pesticide alone.

BACKGROUND: Organophosphate (OP) poisoning results in significant toxicity while pyrethroid poisoning is associated with extremely low fatality. OPs can inhibit the detoxification of pyrethroid and increase the toxicity of the combination. We assessed whether mixed OP-pyrethroid poisoning impacted outcome in human poisoning. METHODS: Patients were identified from a prospectively collected institutional poisoning database that incorporates demographic and outcome data of patients presenting with poisoning. RESULTS: Of the 1177 poisoned patients admitted over 2 years, 32 presented with OP-pyrethroid (50% chlorpyrifos-5% cypermethrin mixture) poisoning (Group 1), 26 consumed 20% chlorpyrifos (Group 2), and 32 took 15% cypermethrin (Group 3). Seizures occurred in 15.6% (n = 5) with chlorpyrifos-cypermethrin poisoning, 18.8% (n = 6) with cypermethrin poisoning, and 3.9% (n = 1) with chlorpyrifos poisoning. Ventilatory requirements were 53.5% (17/32), 42.3% (11/26), and 15.7% (5/32) in Groups 1-3, respectively. Ventilator-free days (Mean ± SD) was significantly lower (p < 0.006) in Group 1 (20.9 ± 9.3 days) than those in Group 2 (26.1 ± 4.4 days) or 3 (27.8 ± 0.6). The median (inter-quartile range) hospital stay was 5.5 (4-19.5), 5 (5-6), and 1 (0.65-1.5) days, respectively, in the three groups. Four patients died in Group 1 (13%). None died in the other groups. CONCLUSION: Although confounded by the varying quantity of chlorpyrifos and cypermethrin in the different formulations, patients with mixed poisoning appear to have shorter ventilator-free days than patients poisoned by either of the pesticides alone. Further studies are required comparing patients poisoned by formulations with similar quantities of OP and pyrethroid or with analysis of blood pesticide concentration on admission.

Performance of clinical scoring systems in acute organophosphate poisoning.

INTRODUCTION: Clinical scoring systems are used to predict mortality rate in hospitalized patients. Their utility in organophosphate (OP) poisoning has not been well studied. METHODS: In this retrospective study of 396 patients, we evaluated the performance of the Acute Physiology and Chronic Health Evaluation (APACHE) II score, the Simplified Acute Physiology Score (SAPS) II, Mortality Prediction Model (MPM) II, and the Poisoning Severity Score (PSS). Demographic, laboratory, and survival data were recorded. Receiver operating characteristic (ROC) curves were generated, and the area under the curve (AUC) was calculated to study the relationship between individual scores and mortality rate. RESULTS: The mean (standard deviation) age of the patients was 31.4 (12.7) years, and at admission, their pseudocholinesterase (median, interquartile) level was 317 (222-635) U/L. Mechanical ventilation was required in 65.7% of the patients and the overall mortality rate was 13.1%. The mean (95% confidence interval) scores were as follows: APACHE-II score, 16.4 (15.5-17.3); SAPS-II, 34.4 (32.5-36.2); MPM-II score, 28.6 (25.7-31.5); and PSS, 2.4 (2.3-2.5). Overall, the AUC for mortality was significantly higher for APACHE-II (0.77) and SAPS-II (0.77) than the PSS (0.67). When patients were categorized, the AUCs were better for WHO Class II (0.71-0.82) than that for Class I compounds (0.60-0.66). For individual compounds, the AUC for APACHE-II was highest in quinalphos (0.93, n = 46) and chlorpyrifos (0.86, n = 38) and lowest in monocrotophos (0.60, n = 63). AUCs for SAPS-II and MPM-II were marginally but not significantly lower than those for APACHE-II. The PSS was generally a poorer discriminator compared to the other scoring systems across all categories. CONCLUSIONS: In acute OP poisoning, the generic scoring systems APACHE-II and SAPS-II outperform the PSS. These tools may be used to predict the mortality rate in OP poisoning.