Administration Of Atropine Sulfate Research Articles

Is prolongation of corrected QT interval associated with seizures induced by electroconvulsive therapy reduced by atropine sulfate?

Electrocardiogram abnormalities have been reported during electroconvulsive therapy (ECT). A corrected QT interval (QTc) prolongation indicates delayed ventricular repolarization, which can trigger ventricular arrhythmias such as torsade de pointes (TdP). We examined the QTc changes during generalized tonic-clonic seizures induced by ECT, and the effects of atropine sulfate on these QTc changes. We analyzed heart rate, QT interval, and QTc in 32 patients with depression who underwent ECT (25 women, 67.4 ± 8.7 years of age). The QTc from -30 to 0 seconds prestimulation was used as baseline, which was compared with QTc at 20-30 seconds and 140-150 seconds poststimulus onset. QTc was significantly prolonged at 20-30 seconds poststimulus, then significantly decreased at 140-150 seconds poststimulus, compared with baseline. QTc prolongation induced by ECT was significantly decreased by atropine sulfate. These data suggest that the risk of TdP may be enhanced by ECT. Further, the risk of cardiac ventricular arrhythmias, including TdP, may be reduced by administration of atropine sulfate.

Evaluation of the efficacy of an oral magnet administration for the treatment of traumatic reticuloperitonitis in cattle

Magnets were administered orally in 42 cows diagnosed with traumatic reticuloperitonitis (TRP) with radiographic evidence of sharp foreign bodies in their reticulum, and without any prior administration of atropine sulphate. Upon radiologic investigation, magnets were observed within the reticulum in 40 cases and foreign bodies were attached to the magnet in 24 cases. In 8 cases, though foreign bodies were dislodged but their attachment could not be clearly discerned. Foreign bodies were not attached to the magnet in 4 cows due to the presence of nonferromagnetic foreign bodies and in 2 cows because the foreign bodies were penetrating deep through the wall of the reticulum. In 2 cases, the foreign body was unattached to magnet and located close to magnet probably in the magnetic field. The radiological findings of foreign body attachment, non-attachment or displacement were confirmed in 14 animals by rumenotomy. It was concluded that magnet therapy is effective and radiological diagnosis is a reliable tool in making decision about surgical intervention in cases of TRP following administration of magnet.

P.1.g.038 - Antimuscarinic-induced convulsions in fasted animals after food intake produced no spontaneous seizures, behavioral changes, or neuronal damage

The present study examined the effects of systemically administered atropine sulfate, a muscarinic cholinergic antagonist, on a series of probe tests in the retention of a highly-structured serial pattern in a serial multiple choice (SMC) task. Rats were trained on a 24-element pattern composed of eight 3-element chunks ending with a violation element: 123-234-345-456-567-678-781-818 where the digits represent the clockwise position of levers in an octagonal chamber, dashes indicate 3-s pauses termed “phrasing cues,” and other intertrial intervals were 1 s. In daily acquisition trials rats were given either 50 mg/kg of atropine sulfate or an equivalent amount of saline (Chenoweth & Fountain, 2015). Following acquisition, rats were given a series of drug challenges, and the present study reports a series of Phrasing Cue Removal Probes that tested rats’ abilities to make correct responses in the absence of phrasing cues. Rats tested under atropine demonstrated more difficulty in recalling encoded responses in these probe trials than did rats tested under saline. The results indicate that intact central muscarinic cholinergic systems were needed for rats to display efficient adaptive response strategies under conditions where some features of the previously-learned pattern change.

Strategy breakdown following muscarinic blockade in rats

The present study examined the effects of systemically administered atropine sulfate, a muscarinic cholinergic antagonist, on a series of probe tests in the retention of a highly-structured serial pattern in a serial multiple choice (SMC) task. Rats were trained on a 24-element pattern composed of eight 3-element chunks ending with a violation element: 123-234-345-456-567-678-781-818 where the digits represent the clockwise position of levers in an octagonal chamber, dashes indicate 3-s pauses termed “phrasing cues,” and other intertrial intervals were 1s. In daily acquisition trials rats were given either 50mg/kg of atropine sulfate or an equivalent amount of saline (Chenoweth & Fountain, 2015). Following acquisition, rats were given a series of drug challenges, and the present study reports a series of Phrasing Cue Removal Probes that tested rats’ abilities to make correct responses in the absence of phrasing cues. Rats tested under atropine demonstrated more difficulty in recalling encoded responses in these probe trials than did rats tested under saline. The results indicate that intact central muscarinic cholinergic systems were needed for rats to display efficient adaptive response strategies under conditions where some features of the previously-learned pattern change.

Use of a porcine urinary bladder acellular matrix for corneal reconstruction in dogs and cats.

To describe the use of a porcine urinary bladder acellular matrix for surgical reconstruction of the cornea in cases of canine and feline deep corneal ulcers, and feline corneal sequestra. Twenty-seven dogs and three cats with deep corneal ulcers and seven cats with corneal sequestra were included in the study with overall 38 eyes. For each patient, the necrotic material (ie corneal sequestrum or collagenolytic tissue) was removed by circular lamellar keratectomy. The collagen graft was then cut and prepared to match the stromal defect and then sutured into the lamellar keratectomy bed using interrupted and continuous patterns of absorbable polyglactin 9-0 sutures. Postoperative medical treatment consisted of topical and systemic administration of antibiotics, combined with topical administration of atropine sulfate. The animals were examined 18, 45, and 90 days after the surgery. Postoperative examination revealed complete integration of the biomaterial in 93.5% of ulceration cases in both species and in 100% of feline corneal sequestrum cases. In two cases of ulceration (1 dog and 1 cat), progression of the collagenolytic process at the graft periphery required an additional conjunctival graft 7 days after the first surgery. At 90 days post-op, 100% of the eyes were sighted. Use of a porcine urinary bladder acellular matrix appears to be effective in the surgical management of deep corneal ulcers and feline corneal sequestra.

Orthostatic Dysregulation during Postural Change on the Dental Chair and Intraoperative Monitoring by Heart Rate Variability Analysis.

This is the first case report of orthostatic dysregulation (OD) manifested during postural change on the dental chair and intraoperatively monitored by heart rate variability (HRV) analysis. OD-associated autonomic dysfunction is induced by postural changes and easily leads to disturbance in circulatory dynamics; however, most dental practices have not yet realized the importance of managing OD. We measured autonomic activity in a patient with OD during dental therapy and assessed the clinical significance of HRV analysis for OD. The patient was a 17-year-old Japanese female. She was diagnosed with impacted wisdom teeth and had no previous history of a distinct systemic disease. A surgical procedure to extract the teeth was safely performed under both local anesthesia and sedation with nitrous oxide and midazolam. After the surgery, her postural change to sitting induced orthostatic hypotension. HRV variables showed parasympathetic dominance due to the upright position. Subsequently, her posture was returned to supine, and atropine sulfate administration for the immediate treatment of OD returned her blood pressure to normal levels. HRV variables showed relative sympathetic dominance due to an atropine-derived parasympathetic blockade. HRV analysis revealed OD-associated autonomic dysfunction and should become a standard tool for safe and secure dental management of OD.

Reversal of hemorrhagic shock in rats using the metabolically stable thyrotropin-releasing hormone analog taltirelin hydrate

We investigated the effect of taltirelin hydrate ((−)-N-[(S)-hexahydro-1-methyl- 2,6-dioxo-4-pyrimidinyl-carbonyl]-L-histidyl-L-prolinamide tetrahydrate; taltirelin), a metabolically stable thyrotropin-releasing hormone (TRH) analog, on circulatory function, respiratory function, and viable time after bleeding in urethane-anesthetized rats. Massive volume-controlled bleeding caused marked reductions in mean arterial pressure (MAP) and respiratory rate (RR). The vital signs of control rats were lost within an average of 23 min after bleeding. Intravenous administration of taltirelin (0.03–0.3 mg/kg) and TRH (1 and 3 mg/kg) immediately after bleeding accelerated recovery of MAP and RR, and prolonged viable time in a dose-dependent manner. The potency of taltirelin in accelerating MAP and RR recovery and prolonging viable time was higher when compared with that of TRH. In addition, recovery of MAP and RR and the extension of viable time by taltirelin were inhibited by preintraperitoneal administration of atropine sulfate, which is a centrally acting muscarinic antagonist, but not by that of atropine methylbromide, which is a peripherally acting muscarinic antagonist. Taltirelin also recovered decreased arterial pH, bicarbonate ions, and base excess, and prevented a decrease in arterial oxygen saturation. In conclusion, the anti-shock effect of taltirelin was more potent than that of TRH. Taltirelin activity was mediated by the central muscarinic cholinergic system. In addition, taltirelin also corrected metabolic acidosis. These results suggest that taltirelin could be useful in the treatment of hypovolemic shock.

Application of an enantioselective LC‐ESI MS/MS procedure to determine R‐ and S‐hyoscyamine following intravenous atropine administration in swine

S-hyoscyamine (S-hyo) is a natural plant tropane alkaloid acting as a muscarinic receptor (MR) antagonist. Its racemic mixture (atropine) is clinically used in pre-anaesthesia, ophthalmology and for the antidotal treatment of organophosphorus (OP) poisoning with nerve agents or pesticides even though R-hyo exhibits no effects on MR. Further investigative research is required to optimize treatment of OP poisoning. Swine are often the animal model utilized due to similarities in physiology and antidote response to humans. However, no studies have been reported that elucidated differences in the kinetics of R- and S-hyo. Therefore, the concentration-time profiles of total hyo as well as both enantiomers were analyzed in plasma after intravenous administration of atropine sulfate (Atr(2) SO(4) , 100 µg/kg) to anaesthetized swine. For quantification plasma samples were incubated separately with human serum (procedure A) and rabbit serum (procedure B). The rabbit serum used contained atropinesterase, which is suitable for stereoselective hydrolysis of S-hyo, while human serum does not hydrolyze either enantiomer. After incubation samples were precipitated and the supernatant was analyzed by RP-HPLC-ESI MS/MS. Procedure A allowed determination of total hyo and procedure B remaining R-hyo concentrations. S-hyo was calculated as the difference of the two procedures. Concentration data were regressed by a two-phase decay according to a two-compartment open model revealing similar kinetics for both enantiomers thus indicating distribution, metabolism and elimination without obvious stereoselective preference in tested swine.

In Vivo Ocular Efficacy Profile of Mapracorat, a Novel Selective Glucocorticoid Receptor Agonist, in Rabbit Models of Ocular Disease

To compare the efficacy of mapracorat (formerly ZK-245186, and subsequently BOL-303242-X), a novel selective glucocorticoid receptor agonist (SEGRA), with that of dexamethasone (DEX) in rabbit models of ocular disease. The effects of topical BOL-303242-X and DEX on intraocular pressure (IOP) and body weight changes were also evaluated. Dry eye was induced by atropine sulfate administration and was treated with saline, BOL-303242-X (0.1%-1.0%), DEX (0.1%), Restasis 0.05% (Allergan, Inc., Irvine, CA), or Refresh Endura (Allergan, Inc.) three times per day for 7 to 8 days. For paracentesis studies, vehicle, BOL-303242-X (0.1%, 0.5%, and 1.0%), or DEX (0.1%) were repeatedly administered topically 3 hours before paracentesis and continued for 90 minutes afterward. For IOP and body weight measurements, right eyes of rabbits were topically treated with vehicle, BOL-303242-X (1.0% or 0.1%), or DEX (0.1%) four times per day for 6 weeks. In the dry eye model, BOL-303242-X and DEX were fully efficacious, maintaining tear volume and tear breakup time (TBUT) at baseline levels. Although Restasis improved tear volume compared with vehicle, no changes were observed in TBUT. In the paracentesis study, BOL-303242-X and DEX improved ocular inflammation. BOL-303242-X reduced protein and PGE(2) levels. Finally, BOL-303242-X showed no effects on integrated IOP or body weight, whereas DEX significantly increased integrated IOP and prevented the increase of body weight observed in the vehicle-treated animals. BOL-303242-X shows full anti-inflammatory efficacy (similar to DEX) in experimental models of dry eye and postoperative inflammation while demonstrating reduced effects in IOP and body weight. These data indicate that mapracorat, a SEGRA, shows efficacy similar to that of traditional steroids while exhibiting an improved side effect profile in IOP and muscle wasting.

Clinical and bioavailability studies of sublingually administered atropine sulfate

Introduction The increased use of organophosphorus (OP) pesticides and the ever increasing possibility of terror groups using nerve agents underscore a need to develop effective and safe antidotes against OP poisoning. The objectives of the present study were to develop a novel atropine sulfate (AS) sublingual injection formulation, to create its bioavailability data in humans and to evaluate its suitability for field use with a view to obtain early therapeutic drug concentration in comparison to the conventional intramuscular route that provides a therapeutic peak of 6 to 8 ng/mL in blood at 30 minutes. Methods Two milligrams per 0.1 mL of AS was sublingually injected in 6 volunteers, and bioavailability and atropinization signs (blood pressure, pupil diameter, and heart rate) were noted. Results Human bioavailability curve was created, which was equivalent to 2 mg IM injection in amplitude within 10 minutes and describing a better curve thereafter. Peak plasma concentration of AS occurred at 15 minutes and was 21 ng/mL. Increase in heart rate became extremely significant at 5 minutes ( P < .0001) with maximum increase of 62% ± 6% at 10 minutes after administration. Pupil diameter showed maximal increase of 58% ± 21% at 15 minutes ( P < .01). Conclusions Sublingual AS appears to have several advantages over conventional IM route including better bioavailability, rapid onset of action, and early atropinization. It is a safe and efficacious procedure with the potential to become an alternative to conventional IM injection, particularly in case of chemical terrorism scenario where hundreds of victims may require immediate atropinization simultaneously.

In vivo oxime administration does not influence Ellman acetylcholinesterase assay results

Organophosphorus compounds (OPs) are potent inhibitors of acetylcholinesterase (AChE). Treatment for OP poisoning is by administration of atropine sulfate, an oxime, and diazepam. Oximes such as 2-PAM are used to reactivate OP-inhibited AChE so as to restore normal enzymatic function and serve as a true antidote. There are reports of non-enzymatic hydrolysis by oximes of acetylthiocholine in in vitro preparations in the widely used Ellman assay for AChE activity, which may confound the interpretation of AChE activity by producing elevated results. The purpose of this experiment was to determine if there is appreciable interference by therapeutic levels of oximes on the results of the Ellman assay in assessing AChE reactivation by oxime compounds in vivo. When therapeutic doses of oximes (2-PAM, HI-6, MMB-4, or MINA) were administered intramuscularly to guinea pigs and samples collected 60 min later, there was no statistical difference between oxime and saline control groups in measured AChE activity in various tissue samples, including blood. With appropriate dilution of samples prior to spectrophotometric assay, the Ellman assay is an acceptable method to measure in vivo oxime reactivation of inhibited AChE. Inclusion of an oxime control group to insure that this particular type of interference is not causing false readings in the assay is a prudent step.

Changes in electrophysiologic properties of the conductive system of the heart in children with atrioventricular nodal reentrant tachycardia after 2–8 years following radiofrequency catheter ablation of the slow pathway

Radiofrequency ablation of the slow pathway is an effective method of treatment in children with atrioventricular nodal reentrant tachycardia. The aim of our study was to evaluate anterograde conduction properties in children before and after radiofrequency ablation of the slow pathway and to determine the efficacy and safety of this method. Noninvasive transesophageal electrophysiological examination was performed in 30 patients at the follow-up period (mean duration, 3.24 years) after radiofrequency ablation of the slow pathway. The slow pathway function was observed in 13 patients one day after ablation, in 26 patients during the follow-up period, and in 28 patients after administration of atropine sulfate. Atrioventricular node conduction was significantly decreased the following day after ablation and at the follow-up versus the preablation (165.2 [30.2] bmp and 146.3 [28.5] bpm versus 190.9 [31.4] bpm; P<0.001). The atrioventricular node effective refractory period prolonged significantly the following day after ablation and at the follow-up versus the preablation (319.3 [55.3] ms and 351.0 [82.1] ms versus 248.3 [36.6] ms; P<0.001). Effective refractory period of the fast pathway prolonged significantly as compared with the preablation (from 408.0 [60.4] ms to 481.2 [132.9] ms; P=0.005). The prolongation of effective refractory period of the slow pathway was more significant than effective refractory period of the fast pathway at the follow-up (P<0.001). Two late recurrences occurred; one patient had atrial tachycardia. Children with atrioventricular nodal reentrant tachycardia can be effectively and safety cured by ablative therapy. The end-point during slow pathway ablation should be the abolition of tachycardia with preservation of dual atrioventricular nodal physiology.

Characteristics of Acetaminophen Absorption in Healthy Unweaned Calves as an Indirect Measurement of the Oroduodenal Transit Rate of Liquid Meals

Abomasal emptying plays an important role in the incidence of digestive problems in calves. Our aim was to evaluate the acetaminophen absorption test (APAT) for characterization of the oroduodenal transit (ODT) of liquid meals in unweaned calves. Six healthy, unweaned Simmental x Red Holstein crossbred calves were involved in the project. The study was performed in three blocks at 3, 6 and 9 weeks of the calves' age. Within blocks, APAT was performed twice at an interval of at least 24 h. Once per each block, liquid transit was carried out with non-coagulating electrolyte solution (NES). The second test within a block was performed either while atropine sulphate was administered (block I), or by feeding a coagulating milk replacer (block II), or by administration of NES by ruminal tube (block III). Data were compared within and among blocks. Significant differences of several APAT traits were present for the different types of feeding, the different types of meals, the administration of atropine sulphate and the different ages of the calves. The emptying index T(max)/C(max) was suggested to be a valuable kinetic parameter for the characterization of ODT in these calves. We conclude that APAT represents a valid technique for characterization of ODT of liquid meals in healthy unweaned calves and may be a valuable tool for the evaluation of the reticular groove mechanism, the abomasal emptying and the absorption capacity of the duodenum.

Methyl parathion increases neuronal activities in the rat locus coeruleus

Exposure to organophosphate insecticides induces undesirable behavioral changes in humans, including anxiety and irritability, depression, cognitive disturbances and sleep disorders. Little information currently exists concerning the neural mechanisms underlying such behavioral changes. The brain stem locus coeruleus (LC) could be a mediator of organophosphate insecticide-induced behavioral toxicities since it contains high levels of acetylcholinesterase and is involved in the regulation of the sleep-wake cycle, attention, arousal, memory, and pathological processes, including anxiety and depression. In the present study, using a multi-wire recording technique, we examined the effects of methyl parathion, a commonly used organophosphate insecticide, on the firing patterns of LC neurons in rats. Systemic administration of a single dose of methyl parathion (1 mg/kg, i.v.) increased the spontaneous firing rates of LC neurons by 240% but did not change the temporal relationships among the activities of multiple LC neurons. This dose of methyl parathion induced a 50% decrease in blood acetylcholinesterase activity and a 48% decrease in LC acetylcholinesterase activity. The methyl parathion-induced excitation of LC neurons was reversed by administration of atropine sulfate, a muscarinic receptor antagonist, indicating an involvement of muscarinic receptors. The methyl parathion-induced increase in LC neuronal activity returned to normal within 30 min while the blood acetylcholinesterase activity remained inhibited for over 1 h. These data indicate that methyl parathion treatment can elicit excitation of LC neurons. Such excitation could contribute to the neuronal basis of organophosphate insecticide-induced behavioral changes in human.

The relationship between salivary secretion rate and masticatory efficiency.

In order to elucidate the relationship between the salivary secretion rate and masticatory efficiency, experimental hypo- and hyper-salivation were produced by the administration of atropine sulphate presenting an anticholinergic effect and pilocarpine hydrochloride having a muscarine effect orally in 10 healthy fully dentates. To confirm the pharmaceutical effect of these drugs, the unstimulated whole salivary secretion rate during 10 min, and masticatory efficiency using the sieve method were measured before and after medication. The unstimulated whole salivary secretion rate during 10 min decreased significantly by the administration of atropine sulphate (P < 0.05), and increased significantly by pilocarpine hydrochloride (P < 0.01). The masticatory efficiency after atropine sulphate medication was significantly lower than that before (P < 0.01). The increase in salivary secretion by pilocarpine hydrochloride did not lead to a higher masticatory efficiency. The evidence supports the understanding that saliva plays an important role in masticatory function.

重篤な循環器症状を呈したバイケイソウ中毒の治療経験

A 62-year-old woman was transferred to our hospital complaining of nausea, vomiting and acute abdominal pain four hours after the ingestion of wild grass. Her initial systolic blood pressure was 60mmHg and her heart rate was 40beats/min. Her vital signs improved following the administration of atropine sulfate and dopamine. Since the species of the ingested plant was not known at the time of admission, hemoperfusion and hemodialysis appeared to be the best methods of treatment. On the next day, her vital signs stabilized and her complaints were alleviated. The plant was later revealed to be Veratrum album. Veratrum album is a toxic wild plant that is frequently encountered in Japan and is often mistaken for Hosta sieboldiana. Since acute intoxication by veratrum alkaloids may cause severe parasympathetic symptoms, including profound hypotension and bradycardia, early recognition and treatment are required.

Conservative treatment of hypertrophic pyloric stenosis in children

Hypertrophy of the pylorus causing obstruction of the gastric outlet, or infantile hypertrophic pyloric stenosis (IHPS), is the most common indication for abdominal surgery in infancy. The incidence of the condition is 3-4 per 1000 live births, and male infants are affected more often than females, in 4:1 ratio. Vomiting, as the first symptom, most often occurs between the third and fourth week after birth, rarely after second month, but there have been few reports of vomiting as late as 5 months. Etiology of IHPS is still controversial. Two theories have been quoted most: absence of non-adrenergic and non-cholinergic nerve fibers which are mediators of smooth muscle contraction, and absence of nitric oxide inhibitory innervation of pyloric smooth-muscle resulting in unopposed contraction of the sphincter in response to muscarinic stimulation. Atropine sulfate is known to inhibit acetylcholine competitively in neuroreceptors, acting peripherally as a competitive inhibitor of the muscarinic effects of acetylcholine, leading to decreased gastrointestinal peristalsis. This action is believed to be important in IHPS cases. The aim of this paper is to provide further information on potential role of atropine in the management of patients with IHPS. From April 2000 to October 2002, 22 patients (16 boys and 6 girls), aged 21 days to 3 months, with IHPS were treated by oral administration of atropine sulfate in our institution. Diagnosis of IHPS was based on US examination in all cases. A nasogastric tube was inserted and left in situ. Medical treatment involved initial correction of fluid and electrolyte imbalance combined with oral administration of atropine sulfate. Atropin was given in the form of aqueous solution in initial dose of 0.05 mg/kg/d. The total daily dose was divided into 8 equal doses. Each dose was formulated to be given in a volume of 1 ml. Before the administration of each dose of atropine, stomach was decompressed by suction via nasogastric tube. The infant was placed on the right side with the head on the cot elevated 20 degrees to 30 degrees for 15 to 30 minutes after each atropine dose. Oral feeding with 10 ml of 10% glucose was then attempted. If feeding was tolerated, the same dose of atropine was administered 3 hours later, followed by a trial of 20 ml of 10% glucose. If tolerated, 10 ml of conventional formula was then tried after atropine administration 3 hours later. The volume of formula was then increased 10 ml per feed until full feeding (120 ml/kg/d) was tolerated. Dribbling (2-3 times per day) was ignored. If vomiting occurred, the same dose of atropine, volume and type of feed, were tried again 3 hours later, and if still not tolerated, atropine was increased by 1 microg/kg/dose without increasing the volume of feed. This approach was repeated until oral feeding was tolerated at least twice, and only then the volume of oral feed was increased. During night shift (between 11 p.m. and 5 a.m.), atropine concentration and amount of oral feed were not increased. If vomiting recurred, the volume of oral feed was decreased to the last tolerated volume and maintained until the following day. Oral atropine was increased until predetermined maximum oral dose (0.1 mg/kg/d) was reached. If oral administration of atropine was ineffective, a decision to perform pyloromyotomy was made no later than 7 days after commencement of oral atropine. Atropine had effect (vomiting frequency less than twice per day) on average 3.29 days (range 1-7 days) from commencement. Oral atropine was tolerated very well, and was effective in 18 cases. Four cases were referred to pyloromyotomy, on day 4 (2 patients), day 5 (1 patient) and on day 6 (1 patient) of atropine treatment. Therapy was continued until US showed normalization of pyloric muscle thickness, passage of food through wide pyloric channel and until patients started gaining weight. Average duration of therapy was 24.05 days (11-39 days). Neither of patients from our group was treated with intravenous atropine sulfate. Although intravenous atropine is more effective (as shown by Nagita et al), there is an increased incidence of side effects such as flushing and tachycardia. Oral atropine has been used successfully by other teams without side effects, and there were no side effects or complications related to the use of atropine in this study. Prospective, randomized study comparing outcomes of medical versus surgical management of IHPS in our hospital has been currently in progress and will provide further information on potential role of atropine in the management of patients with IHPS. We believe it is unlikely that oral or intravenous atropine will ever replace surgery for IHPS, but it may be a good alternative to pyloromyotomy, particularly in children with major concurrent primary disease, or when parents are not enthusiastic about surgery in so young children.

The effect of topical administration of atropine sulfate on the normal equine pupil: influence of age, breed and gender

The purpose of this study was to determine the influence of age, breed and gender on vertical pupil diameter (VPD) following a single dose of 1% atropine sulfate ophthalmic solution in the normal equine eye. Thirty-two horses of various ages, breeds and genders were included. The horses had no history or clinical signs of ophthalmic disease. All horses studied had darkly pigmented irides. Two milligrams of 1% atropine sulfate ophthalmic solution was topically administered as a single dose in the right eye of each horse on Day 0. The VPD (mm) was measured in both eyes using digital calipers prior to treatment and every 24 h after administration for 2 weeks (Days 1-14). Duration of effect on VPD was then calculated for treated and untreated eyes. Data were also analyzed for effect of age, breed and gender on mean VPD, maximum VPD and time to maximum VPD. The VPD in the treated eye was significantly elevated compared to baseline measurements and compared to the untreated eye at all time points. Arabians had a greater mean VPD at Day 0 and on several days following treatment. Females had greater mean VPD compared to males on 5 out of 15 days. Duration of mydriasis after administration of 1% atropine sulfate ophthalmic solution in the normal equine eye is greater than 14 days. Horses of the Arabian breed and female horses may be more sensitive to effects of cholinergic blockade in the eye.

Pulmonary function, cholinergic bronchomotor tone, and cardiac autonomic abnormalities in type 2 diabetic patients.

This prospective study analyzed the involvement of the autonomic nervous system in pulmonary and cardiac function by evaluating cardiovascular reflex and its correlation with pulmonary function abnormalities of type 2 diabetic patients. Diabetic patients (N = 17) and healthy subjects (N = 17) were evaluated by 1) pulmonary function tests including spirometry, He-dilution method, N2 washout test, and specific airway conductance (SGaw) determined by plethysmography before and after aerosol administration of atropine sulfate, and 2) autonomic cardiovascular activity by the passive tilting test and the magnitude of respiratory sinus arrhythmia (RSA). Basal heart rate was higher in the diabetic group (87.8 +/- 11.2 bpm; mean +/- SD) than in the control group (72.9 +/- 7.8 bpm, P<0.05). The increase of heart rate at 5 s of tilting was 11.8 +/- 6.5 bpm in diabetic patients and 17.6 +/- 6.2 bpm in the control group (P<0.05). Systemic arterial pressure and RSA analysis did not reveal significant differences between groups. Diabetes intragroup analysis revealed two behaviors: 10 patients with close to normal findings and 7 with significant abnormalities in terms of RSA, with the latter subgroup presenting one or more abnormalities in other tests and clear evidence of cardiovascular autonomic dysfunction. End-expiratory flows were significantly lower in diabetic patients than in the control group (P<0.05). Pulmonary function tests before and after atropine administration demonstrated comparable responses by both groups. Type 2 diabetic patients have cardiac autonomic dysfunction that is not associated with bronchomotor tone alterations, probably reflecting a less severe impairment than that of type 1 diabetes mellitus. Yet, a reduction of end-expiratory flow was detected.

Radiologic placement of tunneled hemodialysis catheters in occluded neck, chest, or small thyrocervical collateral veins in central venous occlusion.

To evaluate interventional radiologic placement of tunneled hemodialysis catheters in small thyrocervical collateral veins or in occluded veins in the neck or chest in patients with limited venous access. A femoral venous approach was used to recanalize occluded veins or catheterize small collateral veins in 24 patients in whom all major central veins were occluded. A loop snare or catheter was used as a target for antegrade puncture. Metallic stents were deployed if necessary. Once antegrade access was secured, catheters were placed in a conventional fashion. Technical success was achieved in 22 (88%) of 25 procedures (one patient underwent two procedures). All catheters functioned immediately after placement. There were two procedural complications: a vasovagal episode requiring intravenously administered atropine sulfate and an episode of respiratory distress requiring intubation. There were no instances of pneumothorax, nerve injury, or bleeding complications. Catheter malfunction requiring exchange occurred at a rate of 0.67 per 100 catheter days. Infection requiring catheter removal occurred at a rate of 0.06 per 100 catheter days. Primary patency was 90% at 1 month, 71% at 6 months, and 25% at 12 months. Secondary patency was 100% at 6 months and 70% at 12 months. In patients undergoing hemodialysis in whom conventional venous access sites have been exhausted, interventional radiologic venous recanalization for the placement of permanent catheters is safe and effective. Catheters placed in recanalized veins or small collateral veins have shorter primary patency rates compared with those of conventionally placed catheters, but the former can be maintained for relatively long periods.