Doses Of Atropine Research Articles

Nicotine-like discriminative stimulus effects of acetylcholinesterase inhibitors and a muscarinic receptor agonist in Rhesus monkeys

Acetylcholinesterase (AChE) inhibitors and positive allosteric nicotinic acetylcholine receptor (nAChR) modulators are potential pharmacotherapies for nicotine dependence. Because some smoking cessation aids (e.g. varenicline) appear to work by mimicking the effects of nicotine, we used drug discrimination to examine whether AChE inhibitors and nAChR allosteric modulators mimic the effects of nicotine. Rhesus monkeys discriminated 1.78 mg/kg of nicotine s.c. under an FR5 schedule of stimulus-shock termination. Nicotine and the AChE inhibitors donepezil and galantamine dose-dependently increased responding on the nicotine-appropriate lever with ED50 values of 0.35, 0.22, and 0.77 mg/kg, respectively. Donepezil (0.56 mg/kg) produced nicotine-like effects for at least 6 h, whereas the duration of action of galantamine (1.78 mg/kg) was less than 3 h. The positive allosteric nAChR modulator PNU-120596 (up to 10 mg/kg) and midazolam (up to 1.0 mg/kg) produced no more than 22% nicotine-lever responding. Oxotremorine, a muscarinic acetylcholine receptor agonist that was used to explore the extent to which muscarinic receptor agonism might contribute to the effects of AChE inhibitors, produced 94% nicotine-lever responding (ED50 value 0.013 mg/kg). The muscarinic antagonist atropine significantly antagonized the effects of both oxotremorine and nicotine; however, the dose of atropine antagonizing oxotremorine was smaller than the dose required to antagonize nicotine. Collectively, these results suggest that AChE inhibitors can mimic the effects of nicotine by indirectly stimulating both nicotinic and muscarinic receptors. Inasmuch as some smoking cessation aids work by exerting nicotine-like effects, the current results are consistent with the potential use of AChE inhibitors as novel smoking cessation aids.

Prevention and Management of Myopia and Myopic Pathology

Myopia is fast becoming a global public health burden with its increasing prevalence, particularly in developed countries. Globally, the prevalence of myopia and high myopia (HM) is 28.3% and 4.0%, respectively, and these numbers are estimated to increase to 49.8% for myopia and 9.8% for HM by 2050 (myopia defined as -0.50 diopter [D] or less, and HM defined as -5.00 D or less). The burden of myopia is tremendous, as adults with HM are more likely to develop pathologic myopia (PM) changes that can lead to blindness. Accordingly, preventive measures are necessary for each step of myopia progression toward vision loss. Approaches to prevent myopia-related blindness should therefore attempt to prevent or delay the onset of myopia among children by increased outdoor time; retard progression from low/mild myopia to HM, through optical (e.g., defocus incorporated soft contact lens, orthokeratology, and progressive-additional lenses) and pharmacological (e.g., low dose of atropine) interventions; and/or retard progression from HM to PM through medical/surgical treatments (e.g., anti-VEGF therapies, macula buckling, and scleral crosslinking). Recent clinical trials aiming for retarding myopia progression have shown encouraging results. In this article, we highlight recent findings on preventive and early interventional measures to retard myopia, and current and novel treatments for PM.

CHARACTERISTICS OF PATIENTS WITH ORGANOPHOSPHORUS POISONING AND ITS MANAGEMENT: PHARMACOEPIDEMIOLOGICAL EVALUATION

Objective: The objective of this study was to analyze demographics, management pattern, and clinical outcomes in patients with organophosphorus poisoning.
 Methods: In this subgroup analysis of retrospective data of patients admitted in intensive care unit (ICU) with a diagnosis of acute organophosphorus poisoning, demographic details, pattern of use of medicines, dose of atropine and pralidoxime (PRAM), duration of ICU stay, and clinical outcomes were analyzed.
 Results: A total of 92 patients with organophosphorus poisoning (mean age 34.7 years; male 69 [75%]) were included. The age of male patients was more than female patients (36.2 vs. 30.0 years; p=0.047). Atropine and PRAM were given to all patients. Ondansetron was used in all patients, whereas ranitidine was used in 91 (98.9%) patients. The mean total dose of atropine in male and female population was 99.5 mg and 89.0 mg, respectively (p=0.298). The mean total dose of PRAM in male and female population was 12.2 mg and 12.0 mg, respectively (p=0.772). There was no difference in the mean (standard deviation) duration of stay in ICU between male patients and female patients (7.6 [4.5] vs. 6.4 [3.9] days; p=0.249). A total of 61 (66.3%) patients were transferred to the ward, whereas 30 (32.6%) died.
 Conclusion: Atropine and PRAM are the primary drugs for the treatment of organophosphorus poisoning. Ondansetron and ranitidine are useful drugs for the treatment of vomiting and gastric irritation, respectively, in these patients.

Reduction of oculocardiac reflex with Tetracaine eye drop in strabismus surgery

ABSTRACTIntroduction: Recently, to reduce the incidence of oculocardiac reflex (OCR) in strabismus surgery, retrobulbar block and anticholinergic drugs or local anesthesia are also used. The present study evaluated the effects of Tetracaine eye drop as a topical nerve blocker on OCR during strabismus surgery.Methods and materials: In this randomized trial, 70 strabismus surgery candidates were randomly divided into placebo or synthetic teardrop (E) and Tetracaine eye drop (T) groups, so 3 drops of each solution were dropped in four directions of patients’ eye immediately after applying anesthesia and before surgery. The incidence and severity of OCR during the stages of muscle release and incision (cutting), hemodynamic changes, the required time for OCR recovery and atropine dose were assessed.Results: OCR was more seen in release phase compared to cutting phase. There were no significant differences between two group regarding the incidence and severity of OCR in the release phase (p > 0.05), but the incidence and severity of OCR in the cutting phase was more in group E than group T (p = 0.02, for both). The duration of OCR improvement (p-value = 0.74) and Atropine consumption (p-value = 0.92) did not differ between the groups.Conclusion: Tetracaine eye drop only reduces the incidence and severity of OCR during the incision stage of strabismus surgery.

Safety and efficacy of ketamine xylazine along with atropine anesthesia in BALB/c mice

Anesthetics are an indispensable prerequisite for surgical intervention and pharmacological animal studies. The objective of present study was to optimize the dose of ketamine (K) and xylazine (X) along with atropine sulfate (A) in order to achieve surgical tolerance in BALB/c mice. Several doses of ketamine (100, 150, 200 mg/kg) and xylazine (10, 15, 20 mg/kg) were mixed and combination of nine doses (K/X: 100/10, 100/15, 100/20, 150/10, 150/15, 150/20, 200/10,200/15,200/20) were evaluated (n=9 per combination). A constant dose of atropine (0.05 mg/kg) was also used to counter side effect. Timerelated parameters were evaluated on the basis of reflexes. KX at dose 200/20 mg/kg produced surgical tolerance in all nine mice with duration 55.00±6.87 minutes. The induction time 0.97±0.09 minutes, sleeping time 90.67±5.81 minutes and immobilization time (102.23±6.83 minutes) were significantly higher than all combination. However, this combination was considered unsafe due to 11 % mortality. While, KX at dose 200/15 mg/kg results in none of the mortality, so was considered as safe. Moreover, this combination produces surgical tolerance in 89 % mice with duration (30.00±7.45 minutes). It was concluded that KX at dose 200/15 mg/kg along with atropine 0.05 mg/kg is safe for performing surgical interventions in BALB/c mice.

The Potential Role of Intravenous Magnesium Sulfate Administration on the Outcome of Acute Organophosphorus Toxicity. A prospective study in Poison Control Center Ain Shams University

Background: Organophosphate compounds (OP) have been used as pesticides and chemical warfare nerve agents worldwide. They are readily available because of inadequate regulations controlling their sale. The easy availability of these compounds has resulted in a gradual increase in accidental and suicidal poisoning. It also has resulted in many deaths that occur within hours of the ingestion. The efficacy of the traditional treatment of OP which includes atropine and oximes still an issue of debate. Aim of the Work: Assessing the potential role of intravenous MgSO4 administration on the outcome of acutely OP intoxicated patients via a prospective single-blind randomized controlled trial in the Poison Control Center of Ain Shams University Hospitals (PCC-ASUH). Patients and Methods: The study assesses the potential role of intravenous MgSO4 administration on the outcome of 40 acutely OP intoxicated patients within the period from 8-11-2016 to 18-1-2018. The study is prospective single-blinded randomized controlled trial that was carried out on patients admitted to (PCC-ASUH) with acute OP toxicity. Patients were divided according severity into moderate and severe groups then each group was subdivided into two subgroups; one received MgSO4 and the other didn't receive it. MgSO4 treated patients received 4g/d for only the first 24 hours after admission. Patients were observed for outcomes such as; mortality, total duration of hospital stay, need for ICU admission and its duration and intermediate syndrome and CVS toxicity occurrence. Results: There was no significant difference in duration of ICU stay, total duration of hospital stay and need for mechanical ventilation between MgSO4 treated and non-treated patients. MgSO4 administration may have decreased mortality, intermediate syndrome and CVS toxicity, but the difference was statistically insignificant between MgSO4 treated and non-treated patients Conclusion: Our study found that intravenous MgSO4 administration didn’t modify the total dose of atropine and oximes given to OP intoxicated patients during their hospital stay, also MgSO4 didn’t modify the need for mechanical ventilation. Although MgSO4 had reduced the number of patients who developed intermediate syndrome and CVS toxicity, duration of ICU stay, total duration of hospital stay and mortality, but unfortunately this reduction was statistically insignificant.

Systematic Analysis of Transcriptomic Profile of the Effects of Low Dose Atropine Treatment on Scleral Fibroblasts using Next-Generation Sequencing and Bioinformatics.

This study has two novel findings: it is not only the first to deduct potential genes involved in scleral growth repression upon atropine instillation from a prevention point of view, but also the first to demonstrate that only slight changes in scleral gene expression were found after atropine treatment as side effects and safety reasons of the eye drops are of concern. The sclera determines the final ocular shape and size, constituting of scleral fibroblasts as the principal cell type and the major regulator of extracellular matrix. The aim of our study was to identify differentially expressed genes and microRNA regulations in atropine-treated scleral fibroblasts that are potentially involved in preventing the onset of excessive ocular growth using next-generation sequencing and bioinformatics approaches. Differentially expressed genes were functionally enriched in anti-remodeling effects, comprising of structural changes of extracellular matrix and metabolic pathways involving cell differentiation. Significant canonical pathways were correlated to inhibition of melatonin degradation, which was compatible with our clinical practice as atropine eye drops are instilled at night. Validation of the dysregulated genes with previous eye growth-related arrays and through microRNA-mRNA interaction predictions revealed the association of hsa-miR-2682-5p-KCNJ5 and hsa-miR-2682-5p-PRLR with scleral anti-remodeling and circadian rhythmicity. Our findings present new insights into understanding the anti-myopic effects of atropine, which may assist in prevention of myopia development.

Adjunctive effect of orthokeratology and low dose atropine on axial elongation in fast-progressing myopic children—A preliminary retrospective study

PurposeTo investigate the adjunctive effect of orthokeratology (ortho-k) and low-dose atropine eye drops on axial length elongation in fast-progressing myopic children. MethodsAxial elongation in 60 eyes of 60 subjects who completed two years of ortho-k treatment was retrospectively reviewed. They were aged between 5.6–11.6 (mean, 8.3 ± 1.5) years old when they started ortho-k treatment. During their first year of ortho-k treatment (Phase One), they all demonstrated a faster than 0.25 mm/yr axial elongation rate. They were then treated with nightly 0.01% atropine in addition to ortho-k treatment for another year (Phase Two). Annual axial elongation rates before and after atropine treatment were compared. ResultsBaseline spherical equivalent refractive error was −2.65 ± 1.08 DS and axial length was 24.34 ± 0.92 mm for the study cohort. The mean axial elongation rate was 0.46 ± 0.16 mm/yr during Phase One, being significantly faster in younger children (t = −4.920, P < 0.001). When atropine was added, annual axial elongation rate significantly decreased to 0.14 ± 0.14 mm/yr (t = −11.988, P < 0.001), and those who were fast progressors in Phase One had a greater reduction in the rate of axial elongation during Phase Two (t = −8.052, P < 0.001). ConclusionsAxial elongation rate is faster in younger children undergoing ortho-k treatment. For fast myopia progressors, low dose atropine may significantly slow axial elongation in addition to ortho-k’s treatment effect. Those who have faster axial elongation after ortho-k treatment will benefit more from the addition of low dose atropine, regardless of their refractive error and age.

Maxillomandibulocardiac reflex in a dog

BackgroundThe trigeminocardiac reflex (TCR) is a brainstem reflex that may be observed in anaesthesia during surgical procedures stimulating the intracranial or peripheral portion of the trigeminal nerve. The peripheral TCR is divided into the oculocardiac reflex and the maxillomandibulocardiac reflex based on the affected sensory branches of the trigeminal nerve. In veterinary medicine the oculocardiac reflex has been described, however the maxillomandibulocardiac reflex has never been reported.Case presentationA 5-year-old male Epagneul Breton was presented for surgical management of an upper lip mass. During surgery, a sudden severe bradycardia and a decrease in systemic arterial blood pressure developed. The occurrence of a maxillomandibulocardiac reflex was suspected on the basis of the temporary link between surgical stimulation and haemodynamic changes. Three doses of atropine were given before starting a dopamine infusion due to lack of response. The dopamine infusion normalized heart rhythm and blood pressure. The dog recovered uneventfully and he was discharged 24 h later with a sinus rhythm and no sign of recurrence of arrhythmias.ConclusionThe TCR is a rare but potentially life-threatening complication of procedures involving the sensory areas innervated by the three branches of the trigeminal nerve and it may cause bradycardia with hypotension. The use of a β1-adrenergic receptor agonist such as dopamine may be indicated in cases of a refractory response to the conventional treatment with atropine.

Dexmedetomidine attenuates the positive chronotropic effects of intravenous atropine in patients with bradycardia during spinal anaesthesia: a retrospective study

IntroductionDexmedetomidine is a sedative used during spinal anaesthesia. However, it frequently induces bradycardia. Although intravenous atropine is often used for treating bradycardia during regional anaesthesia, the response to atropine might be attenuated by concomitantly administering sedatives. MethodsWe examined the effects of atropine used for treating bradycardia during spinal anaesthesia among patients receiving dexmedetomidine (D group), propofol (P group), or neither (nonDnonP group) for sedation, retrospectively.ResultsA total of 108 patients were included. Heart rate was significantly slower at all time points in the D group (n = 69) than in the nonDnonP group (n = 14) (p < 0.025 for all). On the other hand, heart rate was significantly slower only 60 min after administration of atropine in the P group (n = 25) than in the nonDnonP group (p = 0.002). There were differences in the overall values of heart rate (including all the values from time 0 to 60 min) among the three groups (p = 0.026).ConclusionsThe positive chronotropic effects of atropine might be attenuated with the use of dexmedetomidine or propofol during spinal anaesthesia. Although atropine may be administered when bradycardia occurs, a dose of atropine might result in an insufficient effect against the bradycardia. The sufficient number of subjects may change the results of the investigation, and large-scale randomised controlled trials will be necessary.

391 Paralysis Following Acute Organophosphate Poisoning Improves Survival and Decreases Pulmonary Secretion Production in a Rat Model

Acute organophosphate poisoning (OP) produces profound pulmonary secretions. Standard treatment therapy includes anticholinergic medications aimed to reduce the volume of pulmonary secretion and mechanical ventilation for pulmonary support. Neuromuscular weakness termed intermediate syndrome attributes to morbidity and mortality related to OP poisoning in about 25% of cases. We have previously found that adding pancuronium to comprehensive medical treatment can preserve nicotinic acetylcholine receptors at the neuromuscular junction. The ideal timing of the first dose of pancuronium may have profound impacts on survival. Our objective was to compare the survival rates following acute OP poisoning in a rats model. Rats were intubated, anesthetized with isoflurane, and ventilated on a mechanical ventilator prior to exposure to intravenous OP (parathion 40mg/kg). Paralysis was initiated at 1, 4 and 7 hours post OP poisoning. Oxygenation saturation, pulse rate, and end-tidal CO2, peak inspiratory pressure (PIP), lung capacity (LC), and lung elastance (LE) were continuously monitored. Treatment with 2-PAM (90 mg/kg), midazolam (0.125mg/kg) and atropine (0.25mg/kg) were initiated at 1) point where pulse rate fell by 25% or 2) 40 minutes post poisoning. 2-PAM was repeated at 6 and 12 hours. Animals remained mechanically ventilated for 16 hours with atropine dosage titrated to volume of pulmonary secretions. All rats received equivalent medications, ventilator support and suctioning practices during the experiment. Pulmonary secretion volume was recorded using graduated suction catheters. Our study was powered to determine a 50% difference in mortality between groups with 10 animals in each group and 23% mortality difference with 22 animals in each group. Overall survival was higher when paralysis was initiated earlier. Baseline physiologic variables did not differ between study groups at the baseline period prior to poisoning. Animals paralyzed at 1 (n=10) and 4 hours (n=11) demonstrated 100% survival, but animals paralyzed at hour 7 hours (n=22) demonstrated 63.6% survival (p=0.035). Prominent respiratory secretions were seen in all animals post poisoning, but secretions were increased in group 3 with delayed paralysis. The average pulmonary secretion volume for each group is in Table 1. Animals with increased volume of pulmonary secretions were treated with higher doses of atropine.Tabled 1Average total pulmonary secretion volume (ul) and total atropine dose (mg) administered in 16 hourGroup 1: 1hr*Group 2: 4hr*Group 3: 7hr*Total Volume of Pulmonary Secretions (ul)122.95123.68276.82Total Atropine Dose1.741.732.17* Delay time of first dose of pancuronium (10mg/kg) Open table in a new tab * Delay time of first dose of pancuronium (10mg/kg)

Efficacy of antidotes and their combinations in the treatment of acute carbamate poisoning in rats

BackgroundPhysostigmine and its analogues neostigmine, pyridostigmine and rivastigmine are carbamates nowadays used in many indications, including antidotal effects against antimuscarinic poisonings, reversal of competitive neuromuscular block, myasthenia gravis, Alzheimer’s disease and prophylaxis against nerve agent intoxications. Use of these medicinal carbamates, but also of carbamate insecticides, created need for research into the potential and mechanisms of action of several antidotes against carbamate poisonings, including anticholinergics and oximes. AimThe goal of this experimental study was to ascertain the life-preserving potential of anticholinergics atropine, hexamethonium and d-tubocurarine, oxime HI-6 and their combinations in rats poisoned with physostigmine or pyridostigmine. Materials and methodsExperiments were performed in Wistar rats. Carbamates were injected subcutaneously (sc) and antidotes intramuscularly (im). Median lethal dose (LD50) in animals treated with antidotes were compared to the ones in saline-treated rats and protective ratios (PRs) were calculated. Atropine (5, 10 and 20 mg/kg), hexamethonium (5, 10 and 20 mg/kg), d-tubocurarine (0.005, 0.010 and 0.020 mg/kg) and oxime HI-6 (25, 50 and 100 mg/kg) were used as monotherapies and in dual combinations, where atropine was the obligatory antidote. Biochemical experiments consisted in measuring of the cholinesterase activities in brain, whole blood and diaphragm in rats 5, 15, 30, 60, 120 and 240 min after poisoning with 0.8 LD50 of physostigmine or pyridostigmine. ResultsAll the tested antidotes assured some degree of protection against the two carbamates. Atropine and hexamethonium produced better protection in physostigmine-poisoned rats, while d-tubocurarine and HI-6 were more efficacious in pyridostigmine-intoxicated animals. Oxime HI-6 50 mg/kg reactivated acetylcholinesterase (AChE) in brain inhibited by physostigmine and in diaphragm inhibited by pyridostigmine. ConclusionsMechanism of physostigmine-induced lethal effect is predominantly central and it involves inhibition of brain AChE, while pyridostigmine produces the same effect exclusively outside the central nervous system, by inhibiting AChE in the respiratory muscles. As a consequence, increasing doses of atropine and their combination with hexamethonium assure excellent protection against physostigmine toxicity, while the best protection against pyridostigmine is provided by a strictly peripherally acting antinicotinic d-tubocurarine and bispyridinium oxime HI-6. The oxime acts as antidote against physostigmine and pyridostigmine poisoning by reactivating AChE in the brain and diaphragm, respectively.

Acute organophosphate poisoning: 17 years of experience of the National Poison Control Center in Serbia

Based on human toxicity studies, by appropriate regulatory decisions, the number of organophosphates (OP) on Serbian market has reduced significantly over the last two decades, followed by a gradual decrease in the number of poisonings by organophoshates, treated at the National Poison Control Centre (NPCC). MethodologyThe aim of this retrospective study is to present data regarding the clinical management of poisoning with OP pesticides at the NPCC, that we collected during the 17 years period (1998–2014). ResultsIn the period 1998–2014, about 17.250 patients were hospitalized at the NPCC, there were around 14.000 patients treated for poisoning by various toxic agents, and among them 410 cases (3%) due to poisoning with OP pesticides. In this period, 92% of OPI poisonings treated in the NPCC were suicidal by intention, while only 8% were due to accidental ingestion or inhalation. The most common clinical signs of poisoning in patients exposed to anticholinesterase pesticides, observed at Clinic of Toxicology of the NPCC were miosis (63.4%), bronchorrhoea (51.9%), vomiting and diarrhea (44.8%), hypotension (19.5%). Acute respiratory insufficiency was registered in 81 (19.7%) and acute cardiocirculatory failure in 16 (3.9%) patients. There were about 25% of most severely poisoned patients. Besides general supportive measures (decontamination, respiratory support), specific pharmacological treatment (atropine, oxime, diazepam) was applied. The highest total administered dose of atropine at NPCC was 6400 mg. However, the most patients received total doses of atropine up to 500 mg (32%). ConclusionAcute poisoning with OP pesticides is not frequent in Serbia, however, it represents important clinical feature due to severity, possible complications and their impact on duration and costs of hospitalization. Initial treatment involves prevention of further absorption and provision of supportive care, followed by administration of specific antidotes. According to its role, the National Poison Control Centre in Belgrade, in addition to treatment of acute poisonings, continuously performs toxicovigilance, i.e. the identification, investigation and evaluation of various toxic risks in the community in order to undertake adequate and timely procedures. Permanent efforts are being made in order to reduce availability and to improve control measures for pesticides marketing.

Evaluation of Serum Creatine Phosphokinase as a Marker of Severity in Organophosphorus Poisoning

Background &amp; Objectives: Organophosphorus (OP) poisoning is an important global health problem. Estimation of erythrocyte cholinesterase (EChE) and butyrylcholinesterase (BChE) as an evidence of OP poisoning is costly and not regularly performed. There are emerging options for new cheaper biochemical markers in relation to OP poisoning like creatine phosphokinase (CPK). The objectives of this study were to measure serum CPK level and correlate it with severity of poisoning, to evaluate clinical and prognostic significance of CPK in OP poisoning, to assess if serum CPK level can be used as an alternative of BChE level to stratify OP poisoning severity.Method: Total 100 patients of OP poisoning without any prior treatment, presenting within 12 hours, were selected and their clinical severity was categorized according to Peradeniya Organophosphorus Poisoning (POP) scale. Level of serum CPK, blood BChE and pH were measured and total dose of atropine required (mg) until final clinical outcome was calculated.Results: Out of 100, 43% patients had mild, 36% moderate and 21% severe clinical picture. There was a significant positive correlation between serum CPK value and requirement of atropine dose in patient with severe POP scale category and negative correlation with pH and serum cholinesterase levels, indicating that more severe the poisoning more will be serum CPK and requirement of atropine doses while less will be pH and serum cholinesterase, (p&lt;0.0001).Conclusions: This study suggests role of serum creatine kinase as surrogate, relatively cheap and easily quantifiable markers of severe OPC exposure and their association.

Inconsistent relation of nonlinear heart rate variability indices to increasing vagal tone in healthy humans.

Prior work has found that linear heart rate variability (HRV) indices do not accurately reflect cardiac vagal control, and nonlinear indices of HRV have been proposed as alternative tools that may better capture cardiac vagal effects. We used progressive low dose atropine to induce changes in cardiac vagal tone to test the hypotheses that nonlinear HRV indices accurately reflect cardiac vagal control, and that their changes in response to low dose atropine correlate with those in RR interval. Changes in RR interval and HRV indices during intravenous injections of saline (control) and 6 cumulative doses of atropine (from 1.4 to 7.2 μg/kg) during controlled breathing at 15 breaths per minute were assessed in 14 young healthy individuals. As expected, low dose atropine increased average RR interval (vagotonic effect). There was no strong association between vagotonic changes in RR interval and the majority of nonlinear HRV indices, either within or among subjects. These data suggest an inconsistent relationship between responses of nonlinear HRV indices and RR interval to changes in cardiac vagal tone. Therefore, nonlinear HRV indices may not be reliable indices of cardiac vagal control in healthy humans.

A Review of Myopia Control with Atropine

Myopia is a global public health issue with a worldwide prevalence of ∼30% and is estimated to rise to 50% by 2050. In addition to the burden associated with routine management of the condition, high myopia predisposes the eye to sight-threatening complications such as myopic maculopathy and glaucoma in adult life. Controlling onset and progression of myopia at a young age can reduce the risk of morbidity associated with high myopia. Progression of myopia can be slowed with various optical, environmental, and pharmaceutical strategies, of which atropine has proven to be the most effective. High-dose atropine (0.5%-1%) is the most effective, but it has significant trade-offs with respect to rebound of myopia on discontinuation and side effects such as photophobia and difficulty with near work (decreased accommodation). Low doses of atropine have been trialed and show a dose-dependent efficacy. However, its mode of action on the ocular tissues leading to slowing eye growth remains unclear and multiple mechanisms and sites in the eye have been postulated to play a role. This review summarizes the role of atropine in controlling myopia and the mechanisms studied to date.

Management of scorpion envenomation at the Faya-Largeau medical post, February-June, 2014.

Scorpion envenomation is common in northern Chad and associated with a high lethality rate. We report the management of 16 cases of scorpion envenomation in 2014 at our Faya-Largeau medical post. Our clinical experience revealed dissociated muscarinic symptoms in patients treated early in contrast to those treated later, who presented cardiogenic shock. In the absence of antivenom, patients with an isolated muscarinic syndrome received small doses of atropine, and their signs and symptoms improved afterwards. Although the use of atropine is controversial, the question here is about using it to treat muscarinic symptoms of scorpion envenomation in the absence of severe hypertension and with no signs of heart failure.

Effect of Endotracheal Tube with Subglottic Suction Port vs Standard Endotracheal Tube on Incidence of Ventilator Associated Pneumonia in Patients of Organo-Phosphate Poisoning

Ventilator associated pneumonia is a hospital acquired infection that develops after 48 hours or more after a patient is intubated with an endotracheal or tracheostomy tube and is put on mechanical ventilation [1]. Ventilator associated pneumonia is most common nosocomial infection in ICU and associated with prolonged hospitalization, increased health care costs, and high attributable mortality. Intubation independently increases the risk of developing nosocomial pneumonia atleast seven fold with a peak incidence occurring around day five of ventilation [2]. Tracheal intubation thwarts cough reflex, compromises mucociliary clearance, injures tracheal epithelial surface, provides a direct conduct for rapid access of bacteria from upper into lower respiratory tract and allows formation of biofilm on Endotracheal tube surface. The combination of these factors puts mechanically ventilated patient at great risk of developing VAP. Aims and Objectives: To study incidence of VAP in ET tube with subglottic suction port versus standard ET tube in cases of O.P poisoning in J.J.M Medical college, Davangere from December 2015-June 2017. Material and Methods: A prospective observational case control study of 80 patients admitted to Red Zone/ICU of J.J.M. Medical College, Davangere. Results: Patients who have presented with Organophosphorous poisoning between the age group of 18 to 60 years who require ventilator support, intubated with standard ET tube and another sub set of patients intubated with ET tube with subglottic suction port were analysed. In this study we found that distribution of various organisms with regards to sputum culture in both groups were pseudomonas being maximum and proteus was found in minimum percentage. When subglottic suction port is used we observed improved patients were 70% and deaths were 30%. When subglottic suction port is not used we observed improved were 55% and death were 45%. Conclusion: VAP is common in patients who are intubated in ICU, which has higher morbidity and mortality among these patients. In our study we observed that atropine usually decreases secretions, but here in this study patient population who were admitted developed secretions instead of adequate atropine dosage and also developed VAP. Use of ET tube with Subglottic suction drainage may prevent VAP in cases of Organo Phosphorous poisoning and also improves patient outcomes.

Hypothermia, bradycardia and hypotension in a Dachshund undergoing a hemilaminectomy

A 3-year-10-month-old female neutered Dachshund was presented for investigation of acute onset paraparesis. Magnetic resonance imaging showed an intervertebral disc extrusion, therefore a dorsal hemilaminectomy was performed. While under general anaesthesia, the patient became hypothermic (33.1 °C) and severely bradycardic, with a concurrent severe decrease in blood pressure. Initial management of the bradycardia included glycopyrrolate at a dose rate of 10 μg/kg, administered twice, however the patient was unresponsive to this. Active warming was initiated and the patient's body temperature slowly increased. A single dose of atropine was administered, following which the patient's bradycardia resolved. It is likely that once the patient's temperature increased, all the vasoactive substances were able to take effect. This suggests that the bradycardia was probably, in part, due to the hypothermia, although other factors may have contributed.

MCCONNELL'S SIGN: AN UNDER-RECOGNIZED FINDING OF RIGHT VENTRICULAR INFARCTION

McConnell's sign is a finding commonly associated with acute pulmonary embolism but it is also seen in right ventricular myocardial infarction. 62 year old hispanic female with HTN, ESRD found down with altered mental status, symptomatic bradycardia was unresponsive to numerous doses of atropine