Effectiveness of therapeutic plasma exchange in patients with intermediate syndrome due to organophosphate intoxication.

OBJECTIVE: We aimed to determine effectiveness of therapeutic plasma exchange (TPE) in patients with intermediate syndrome (IMS) due to organophosphate (OP) intoxication. METHODS: Patients diagnosed with IMS due to OP intoxication were included in this prospective study. Therapeutic plasma exchange procedure was performed with fresh frozen plasma as a replacement fluid via Fresenius-AS-TEC 204 device by Therapeutic Apheresis Unit to patients who developed IMS during follow-up. Samples were taken from patient's blood and waste plasma collected in the device before and after TPE procedure to be studied in laboratory for detection of organic phosphate and pseudocholinesterase (PChE) levels. In this study, SPSS 18.0 software package was used for statistical analysis of the data obtained. Level of statistical significance was taken as P < .05 for all tests. RESULTS: Of all 17 patients, 4 (23.5%) were female, and 13 (76.5%) were male. A statistically significant decrease was detected in organic phosphate levels in the plasma of patients after TPE procedure (P = .012). A statistically significant increase was detected in PChE levels in the plasma of patients after TPE procedure (P = .014). Of 17 patients included in the study, 13 patients showed clinical improvement and were discharged after the TPE process. CONCLUSION: In our study, it was observed that a significant decrease in the level of blood plasma OP and a significant increase in the level of PChE were achieved with TPE process in the early period of IMS due to OP poisoning. This study indicates that TPE is one of the effective treatment options for IMS due to OP intoxication.

QTc intervals in drug poisoning patients with tricyclic antidepressants and selective serotonin reuptake inhibitors.

Commonly used agents of drug poisoning among patients who come to the emergency services are tricyclic antidepressants (TCAs). These drugs may cause defect in cardiac conduction due to the slowdown in the cardiac depolarization and expansions in the QT interval. Selective serotonin reuptake inhibitors (SSRIs) are less expansion of the QT period and lower cardio toxic side effects. The aim of this study was to investigate QTc intervals and prognosis of the patients who come to the emergency service due to TCA and SSRI group antidepressant drug poisoning. In a study of 96 patients, 75 of whom were diagnosed to be poisoned by TCAs (TCA group) and 21 by SSRIs (SSRI group) were examined. Electrocardiographic alterations and QTc intervals all of patients were evaluated. QTc intervals of patients in TCA group were determined to be slightly more than those in SSRI group and it was not statistically significant. In the SSRI group, only one patient had QTc period more than 500 milliseconds (520 milliseconds); however, TCA overdose showed 9 (12%) patients with QTc interval over 500 milliseconds, and QTc values of 2 patients were over 600 milliseconds. In our study, it was determined that SSRI group drugs caused similar expansion of the QTc period as TCA drugs but they did not reach high values like TCA drugs, and their OTc intervals stayed in more innocent levels.

Ultrastructural changes in rat thyroid tissue after acute organophosphate poisoning and effects of antidotal therapy with atropine and pralidoxime: A single-blind, ex vivo study.

BACKGROUND: Organophosphate (OP) insecticides are widely used in both agricultural and landscape pest control, and the potential for human exposure to these compounds is significant. OBJECTIVES: The aims of this study were to investigate the effects of acute poisoning with the OP methamidophos and the effects of antidotal therapy with atropine and pralidoxime on rat thyroid tissue ultrastructure. METHODS: In this single-blind, ex vivo study, male Wistar albino rats weighing 220 to 230 g were divided into 4 treatment groups. Group 1 received a median lethal dose of methamidophos (30 mg/kg) via oral gavage. Group 2 received saline via oral gavage and served as the control group for group 1. Group 3 received methamidophos (30 mg/kg) via oral gavage, and after 8 minutes atropine 0.05 mg/kg and pralidoxime chloride (2-FAM) (40 mg/kg) were administered intraperitoneally (IP). Atropine was titrated to reverse signs of cholinergic excess. Group 4 received saline via oral gavage followed by IP injections and served as the control for group 3. Rat thyroid tissues were examined using electron microscopy, and the histologic changes were examined by a histopathologist who was blinded to treatment. All rats were euthanized by intracardiac blood collection. The rats in groups 1 and 2 were euthanized 8 minutes after treatment. The rats in groups 3 and 4 were euthanized 96 hours after treatment. RESULTS: Thirty-four male rats (aged 16 weeks) were included in the study. The rats were grouped accordingly: group 1 (n = 10); group 2 (n = 7); group 3 (n = 10); and group 4 (n = 7). The mean (SD) pseudocholinesterase (FCE) activity was significantly lower in the methamidophos-treated rats (group 1) compared with the corresponding control group (group 2) (32.6 [17.0] vs 579.4 [59.0] U/L, respectively; P < 0.001). PCE activity was significantly higher in rats treated with atropine and 2-PAM (group 3) (392.5 [39.4] U/L; P < 0.001) compared with those not receiving antidotal therapy (group 1). Group 1 experienced changes in thyrocytes and organelles that were not detected in the antidote-treated rats in group 3. These changes included follicular cell nuclei exhibiting an increase in chromatin content, pyknotic nuclei, mitochondrial degeneration, dilated granular endoplasmic reticulum cisternae, reduced microvilli, and intraluminal cellular debris. Within follicular cells, formation of vacuoles filled with fine granular material was noted. CONCLUSION: Acute OP poisoning was associated with histopathologic effects in rat thyroid tissue that appeared to be mitigated by antidotal therapy in this small animal study. More extensive studies using immunohistochemical methods are needed.

Intracranial hemorrhage associated with methanol intoxication.

Methanol is a common component of gasoline, antifreeze, washer fluid, perfume, household cleaners and various other industrial products. Acute methanol poisoning produces severe metabolic acidosis, serious neurologic sequelae and rarely imaging findings. In this paper, we describe a 35-year-old man with methanol intoxication who was in a comatose stage. Computed tomography (CT) showed widespread brain edema and hemorrhages localized in the supratentorial region of the temporal lobe, nearly 3 x 1 cm in a crescent shape, in the white matter surrounding the capsula externa and extending to the periventricular white matter and occipital lobes. Temporal lobe hemorrhage in our patient might also have been due to the effect of heparinization during hemodialysis, metabolic and lactic acidosis, or formate.

Prognostic value of thyroid hormone levels in acute myocardial infarction: just an epiphenomenon?

The purpose of this study was to investigate whether thyroid hormone levels have any predictive value for mortality in patients presenting to the emergency department with acute myocardial infarction (AMI). Three groups of patients admitted to the emergency department within the 11-month study period were considered eligible: 95 patients with chest pain and proven AMI, 26 patients with chest pain and no AMI, and 114 patients who served as controls with no evidence of any major disease. Cardiac enzymes and the following thyroid hormones were analyzed and compared between groups, regarding effects of historical and demographic factors: thyrotrophin, free triiodothyronine (FT3), total triiodothyronine (TT3), free thyroxine (FT4), and total thyroxine (TT4). Sixteen patients with AMI (16.8%) died within the study period. Troponin T and creatine kinase-B with an M-type subunit levels were significantly higher in the nonsurvivors when compared with survivors. Survivors in the AMI group had higher TT3, TT4, and lower FT4 levels, while the nonsurvivors in the AMI group had higher thyrotrophin and lower TT3, FT3 and FT4 levels than controls. In the AMI group, the nonsurvivors had lower TT3 and FT3 levels than the survivors. A history of diabetes mellitus and/or angina, TT3, or FT3 was an independent predictor of mortality. TT3 and FT3 appear to be independent prognostic factors in patients with AMI.

Ultrastructural effects of acute organophosphate poisoning on rat kidney.

We investigated the ultrastructural effects of the organophosphate compound methamidophos and treatment with atropine and pralidoxime (2-PAM) on rat kidneys. Male Wistar albino rats were assigned to four groups. Group 1 received 30 mg/kg methamidophos, the LD50 for this compound in rats, via oral gavage. Group 2 received only physiologic saline. Group 3 rats received 30 mg/kg methamidophos and were treated with 2-PAM and atropine via intraperitoneal injection when cholinergic symptoms were noted. Group 4 served as a control, and received physiologic saline in equivalent volumes and routes to Group 3. Kidney tissues were prepared for electron microscopic studies. No ultrastructural changes were detected in Group 1 after acute poisoning with methamidophos and in Group 3 treated with antidotes after poisoning. Acute organophosphate poisoning and antidotal treatment in this model are not associated with histopathological changes in the rat kidney but the models with different organophosphate compounds, by administrating the different dosages, may be more illuminative in explaining the effects of these chemicals in kidney.

Ingestion of caustic substances by adults.

Caustic products are responsible for the most serious cases of poisoning, which are always emergency cases. In this paper, we review demographic features and endoscopic results of the patients admitted to a university emergency department with a history of caustic substance ingestion between January 2000 and June 2003. Thirty-seven patients were included in this study. Twenty-one of the patients were female and 16 were male. The mean age of the patients was 30.9 +/- 14.7 years. The agents included sodium hypochlorite in 24 patients and hydrochloric acid in 13 patients. All the patients ingested these agents orally. The mean interval time of admission to emergency department after ingestion of caustic agent was 5.4 +/- 5.6 hours. Endoscopy was attempted in 37 patients. Endoscopic results were as follows: grade 0 in 8 (21.6%) patients, grade 1 in 17 (45.9%) patients, grade 2a in 5 (13.5%) patients, and grade 2b in 7 (18.9%) patients. We believe that early signs and symptoms after caustic substance ingestion are not consistent with the extent of damage, and endoscopy is the only reliable method to assess injury. It is important that efforts should be made to educate the public about the dangers of caustic substances so that their threat may be diminished.

Endocrine effects of organophosphate antidotal therapy.

To determine the endocrine effects of the treatment of organophosphate poisoning, this prospective study was conducted in a university-based emergency department among patients with a history and clinical findings compatible with those of organophosphate poisoning. Thyrotrophin (TSH), free triiodothyronine (FT3), free thyroxine (FT4), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), progesterone (PRG), adrenocorticotropic hormone (ACTH), cortisol, and testosterone (TST) levels were analyzed before and after treatment with atropine and pralidoxime. The Wilcoxon's sign rank sum (nonparametric) test was used to compare dependent variables before and after treatment. A total of 44 patients (19 male; mean age: 28.5 +/- 12.6 y) were enrolled in the study. Patients were hospitalized for 5.4 +/- 1.3 days. Posttreatment ACTH, cortisol, PRL, FT3, FSH, and PRG levels were significantly lower than pretreatment levels (P < .05). The decrease in TSH, LH, and TST levels did not reach statistical significance, while FT4 levels increased following the treatment (P < .05). Six patients were diagnosed on admission with sick euthyroid syndrome, and 11 patients who were euthyroid on admission developed sick euthyroid syndrome following treatment. ACTH, cortisol, PRL, FT3, FT4, FSH, and PRG levels are affected by acute organophosphate poisoning. The change in hormone levels may result from the effects of neurotransmitters, from the direct effect of the toxic agent, or from stress associated with events leading to the poisoning incident.