Placement, management and complications associated with peripheral intravenous catheter use in UK small animal practice.

OBJECTIVES: To describe the techniques for preparation and placement of peripheral intravenous catheters (PIVCs), to describe the complications associated with PIVCs, and to identify factors associated with PIVC complications in small animal practice in the United Kingdom. MATERIALS AND METHODS: A prospective multicentre observational study was undertaken between January 2022 and January 2023. Data collected included patient information, information regarding the placement and maintenance of PIVCs, and PIVC complications, from privately owned cats and dogs presenting to veterinary institutes in the United Kingdom. Patients required a PIVC to be placed as part of their care and the PIVC was anticipated to be in situ for >24 hours to be eligible for PIVC complication analysis. RESULTS: A total of 19 institutes recorded data regarding 382 PIVCs, with 325 (85.1%) placed in dogs and 57 (14.9%) in cats. The most common reasons for placement were to administer intravenous fluid therapy (74.3%) and intravenous medications (71.7%). There were 102 of 382 (26.7%) PIVCs associated with a complication, with limb swelling/suspected phlebitis in 44 of 382 (11.5%) and PIVC dislodgement/patient interference in 30 of 382 (7.9%) PIVCs. Factors associated with increased risk of complication were more than 1 attempt to place the PIVC, a second or subsequent PIVC being placed during hospitalisation, flush frequency different than every 1 to 24 hours, and flush solution with compound sodium lactate. CLINICAL SIGNIFICANCE: Veterinary professionals must be vigilant when monitoring a patient with a PIVC in situ, particularly if a PIVC is associated with one of the aforementioned factors of increased likelihood of complication.

Total Endoscopic Ear Surgery in management of cochleocele: A case series.

Cochleocele is an extrusion or herniation of the endosteum, through an incomplete stapes footplate, into the middle ear. The cochleocele may rupture resulting in a cerebrospinal fluid leak into the middle ear space causing a risk of menigitis. We report six cases of Incomplete Partition Type I with cochleocele which have all been successfully treated using a Totally Endoscopic Ear Surgery approach even during infancy. As the first two cases developed post-operative pseudomonas meningitis, preventative strategies are recommended.

Effectiveness of the Cobb-Stainsby excision arthroplasty.

BACKGROUND: Dislocated metatarsophalangeal joints from clawed or hammer toes can be a disabling consequence of several conditions. The Cobb-Stainsby forefoot arthroplasty combines partial phalangectomy (Stainsby) with extensor tendon transfer to the metatarsal head (Cobb). We present a retrospective, three surgeon case series of 215 toes in 126 patients. METHODS: Early results and complications were gathered from the medical charts of 126 patients who met the inclusion criteria. Seventy-five patients were contactable by phone with a follow up range of 12-82 months (median follow up 45 months). Primary outcome measures were improvement of pain and function, reduction in plantar callosities and cosmetic improvement of the deformity. RESULTS: Pre-operatively all patients presented with pain and shoe wear problems. Post-operatively seventy-two patients (96%) were satisfied, 72 (96%) reported pain relief, 55 (73%) were happy with toe control, 61 (81%) were pleased with cosmesis and 56 (75%) reported unlimited daily activities. Superficial wound infections were observed in 13 of the 126 patients (10%) and two in 75 patients (2%) developed recurrent clawing. CONCLUSION: Our case series demonstrates improved outcomes over alternatives such as the Weil's osteotomy.

Selective non-operative management of ballistic abdominal solid organ injury in the deployed military setting.

This article describes the non-operative management of five patients with ballistic abdominal solid organ injuries in a role 2E medical treatment facility. The selective non-operative management of ballistic abdominal solid organ injury is an accepted management strategy in high-volume civilian trauma centres, and appears to be equally safe and effective in the deployed military setting.

Back muscle fatigue during intermittent prone back extension exercise.

UNLABELLED: The purpose of this study was to estimate the level of muscular activation and muscle fatigue of the low back muscles during the performance of an intermittent prone back extension (PBE) exercise. Forty-one healthy students (24 males and 17 females) lying prone on a bench with the legs fixed performed two maximal voluntary contractions (MVC) in extension, a maximum of 100 repetitions of an intermittent PBE exercise immediately followed by a final MVC in extension. In addition, 12 subjects (11 males and one female) repeated the PBE exercise but with the addition of a 45-N weight on the back. The PBE exercise consisted of a task broken into four 1-s segments, while lying prone on a bench (10 degrees below horizontal): (1) raising the trunk to a horizontal position; (2) holding the trunk in the static phase (10 degrees above horizontal); (3) returning to the original position; and (4) resting on the bench. Electromyography (EMG) was used to measure the level of muscle activity (erector spinae (ES), gluteus maximus (GM), hamstrings (HA)) relative to the maximum voluntary EMG (MVE). RESULTS: Most of the subjects (34 out of 41) completed the 100 repetitions without excessive muscle fatigue according to the post-exercise MVC values. The intermittent PBE increased fatigue in the lumbar and hip extensor muscles in terms of: (1) a decrease in the MVC; (2) an increase in the level of muscle activation; and (3) a decline of the median frequency (MF). There was no gender difference in all EMG measurements. The level of muscle activation in the hip extensors (GM and HA) was associated with task failure (number of repetitions <100) for some subjects and the addition of a weight of 45 N had more impact on HA than ES. In conclusion, the PBE exercise as performed in the present study (including rest intervals), although not very strenuous for our healthy subjects, seems an adequate exercise to measure and train the aerobic capacity of the back muscles. However, to train specifically the back muscles, the exercise must be adjusted to avoid task failure due to possible hip extensor fatigue.

The differential effects of chlorpromazine and haloperidol on latent inhibition in healthy volunteers.

Latent inhibition (LI) is a measure of reduced learning about a stimulus to which there has been prior exposure without any consequence. It therefore requires a comparison between a pre-exposed (PE) and a non-pre-exposed (NPE) condition. Since, in animals, LI is disrupted by amphetamines and enhanced by antipsychotics, LI disruption has been proposed as a measure of the characteristic attentional deficit in schizophrenia: the inability to ignore irrelevant stimuli. The findings in humans are, however, inconsistent. In particular, a recent investigation suggested that since haloperidol disrupted LI in healthy volunteers, and LI was normal in non-medicated patients with schizophrenia, the previous findings in schizophrenic patients were entirely due to the negative effects of their medication on LI (Williams et al., 1998). We conducted two studies of antipsychotic drug effects on auditory LI using a within-subject, parallel group design in healthy volunteers. In the first of these, single doses of haloperidol (1 mg. i.v.) were compared with paroxetine (20 mg p.o.) and placebo, and in the second, chlorpromazine (100 mg p.o.) was compared with lorazepam (2 mg. p.o.) and placebo. Eye movements, neuropsychological test performance (spatial working memory (SWM), Tower of London and intra/extra dimensional shift, from the CANTAB test battery) and visual analogue rating scales, were also included as other measures of attention and frontal lobe function. Haloperidol was associated with a non-significant reduction in LI scores, and dysphoria/akathisia (Barnes Akathisia Rating Scale) in three-quarters of the subjects. The LI finding may be explained by increased distractibility which was indicated by an increase in antisaccade directional errors in this group. In contrast, LI was significantly increased by chlorpromazine but not by an equally sedative dose of lorazepam (both drugs causing marked decreases in peak saccadic velocity). Paroxetine had no effect on LI, eye movements or CANTAB neuropsychological test performance. Haloperidol was associated with impaired SWM, which correlated with the degree of dysphoria/akathisia, but no other drug effects on CANTAB measures were detected. We conclude that the effect of antipsychotics on LI is both modality and pharmacologically dependent and that further research using a wider range of antipsychotic compounds is necessary to clarify the cognitive effects of these drugs, and to determine whether there are important differences between them.

Comparing patency rates between external iliac and common iliac artery stents.

PURPOSE: Placement of intraluminal stents in the common iliac artery (CIA) and external iliac artery (EIA) has become an accepted therapy for treating localized arterial stenoses. The purpose of this study was to compare anatomic patency rates of stents placed in the EIA and CIA for occlusive disease. METHODS: A radiologic computer database was used to identify 69 consecutive male patients at the Minneapolis Veterans Affairs Medical Center from February 1, 1993, through January 31, 1999, who underwent placement of 98 stents (82 Wallstents and 16 Palmaz stents) for physiologically significant iliac artery occlusive disease and varying degrees of chronic limb ischemia. Patients were followed up with surveillance duplex ultrasound scanning examinations 1 day after procedure, 3 months after procedure, and then at 6-month intervals after stent placement. Follow-up angiograms were performed for patients with duplex ultrasound scans that revealed velocities greater than 300 cm/s. Patient risk factors, iliac artery runoff, concomitant outflow procedures, and anatomic patency rates were compared between patients receiving EIA stents and those receiving CIA stents. RESULTS: The mean age for the EIA stent group was 69 +/- 1 years versus 66 +/- 1 years (P =.03) for the CIA stent group. Mean follow-up was 21.4 +/- 2.1 months (+/- SE) for all patients. Patients with EIA stents had more ischemic lower limbs when compared with patients who had CIA stents (P =.05). No differences were found between groups in risk factor analysis (P = not significant). Lesion lengths were similar between groups: EIA, 4.6 +/- 0.6 cm, and CIA, 5. 3 +/- 0.8 cm (P = not significant). The following differences were noted on primary patency rates (EIA group vs CIA group): 1 year (93% vs 88%), 2 years (91% vs 85%), and 3 years (90% vs 78%) (Cox proportional hazards; P =.13). CONCLUSIONS: Anatomic patency rates for EIA and CIA stents appear to be similar despite the fact that patients with EIA stents were older and had more ischemic limbs compared with the patients who had CIA stents.

Antisaccade and smooth pursuit eye movements in healthy subjects receiving sertraline and lorazepam.

Patients suffering from some psychiatric and neurological disorders demonstrate abnormally high levels of saccadic distractibility when carrying out the antisaccade task. This has been particularly thoroughly demonstrated in patients with schizophrenia. A large body of evidence has been accumulated from studies of patients which suggests that such eye movement abnormalities may arise from frontal lobe dysfunction. The psychopharmacology of saccadic distractibility is less well understood, but is relevant both to interpreting patient studies and to establishing the neurological basis of their findings. Twenty healthy subjects received lorazepam 0.5 mg, 1 mg and 2 mg, sertraline 50 mg and placebo in a balanced, repeated measures study design. Antisaccade, no-saccade, visually guided saccade and smooth pursuit tasks were carried out and the effects of practice and drugs measured. Lorazepam increased direction errors in the antisaccade and no-saccade tasks in a dose-dependent manner. Sertraline had no effect on these measures. Correlation showed a statistically significant, but rather weak, association between direction errors and smooth pursuit measures. Practice was shown to have a powerful effect on antisaccade direction errors. This study supports our previous work by confirming that lorazepam reliably worsens saccadic distractibility, in contrast to other psychotropic drugs such as sertraline and chlorpromazine. Our results also suggest that other studies in this field, particularly those using parallel groups design, should take account of practice effects.

Enhancement of latent inhibition in the rat at a high dose of clozapine.

The present experiments investigated clozapine (2.5, 5 and 10 mg/kg) and haloperidol (0.1 mg/kg) administration on latent inhibition (LI) in rats. Clozapine's ability to antagonize amphetamine-induced disruption of LI was also assessed. A conditioned emotional response procedure was employed. In the pre-exposure stage, 'pre-exposed' rats received 10 (Experiment 1) or 40 (Experiment 2) presentations of a flashing light stimulus without reinforcement. During the conditioning phase, the light stimulus was paired with a footshock. At test, LI was expressed by the extent of suppression of water licking during flashing light presentation. Both clozapine (10 mg/kg) and haloperidol (0.1 mg/kg) significantly facilitated LI. In addition, clozapine significantly reversed the disruption of LI induced by amphetamine (1.0 mg/kg). These results with clozapine illustrate that LI is sensitive to antipsychotics which differ in their mode of action and furthermore emphasize the value of LI as a test model for detecting the antipsychotic potential of novel drugs.

Enhancement of latent inhibition in the rat by the CCK antagonist proglumide.

The behavioral paradigm of latent inhibition (LI) involves the retardation of conditioning to a stimulus when paired with reinforcement, if preexposure to that stimulus with no significant consequence has occurred. This phenomenon is believed to reflect a process of learning to ignore stimuli as irrelevant. Disruption in LI can be considered to be an attentional deficit observed in schizophrenia. The neuropeptide cholecystokinin (CCK), which coexists with dopamine (DA) in some brain regions, has been implicated in the pathophysiology of schizophrenia. The present study examined the effects of the nonselective CCK antagonist proglumide on LI (0.25, 0.5, and 1.0 mg/kg) using a conditioned suppression of drinking procedure in rats. For purposes of comparison the effects of haloperidol (0.1 mg/kg) were also investigated. Administration of 1.0 and 0.5 mg/kg, but not 0.25 mg/kg, proglumide was found to reduce suppression of drinking behavior in animals preexposed (PE) to a flashing light stimulus. These animals developed LI under conditions where preexposed control animals exhibited suppression of drinking behavior similar to that of nonpreexposed (NPE) control animals. These findings for proglumide were comparable to the effects on drinking behavior of 0.1 mg/kg haloperidol. The enhancement of LI by proglumide may be interpreted in terms of CCK dopamine interactions. Because CCK may modulate dopamine, the results reported here for proglumide strengthen the argument for the investigation of CCK-based drugs as potential antipsychotic agents.

Enhancement of latent inhibition in the rat by the atypical antipsychotic agent remoxipride.

Latent inhibition (LI) is a behavioural paradigm in which repeated nonreinforced preexposure to a stimulus inhibits the formation of subsequent associations to that stimulus. LI is believed to reflect learning to ignore irrelevant stimuli. Disrupted LI has been suggested as an animal model for the attentional deficits observed in schizophrenia. Remoxipride, a selective dopamine D, antagonist, is an effective antipsychotic with an atypical clinical profile. We investigated the effects of remoxipride (1.0, 5.0, and 10.0 mg/kg) and haloperidol (0.1 mg/kg) administration on LI in rats. A three-stage conditioned emotional response procedure was employed: a) preexposure: preexposed rats received 10 presentations of a flashing light stimulus without reinforcement, and nonpreexposed rats received no exposure: b) conditioning; the preexposed stimulus was paired with a foot shock over a number of trials: c) test: LI was expressed by the extent of suppression of water licking during flashing light presentation. Animals receiving 0.1 mg/kg of haloperidol or 1.0 or 5.0 mg/kg (but not 10.0 mg/kg) of remoxipride treated the preexposed stimulus as irrelevant after a low number of preexposed. These results illustrate that the LI model is equally sensitive to typical and atypical antipsychotics and reemphasises its utility as a test model for detecting the antipsychotic potential of novel drugs.

Twenty-four hour esophageal pH monitoring: technique and application.

In the last three decades, esophageal pH monitoring has progressed from an exclusively laboratory-based physiological research tool to a routine outpatient clinical investigation in patients with one of the most common gastrointestinal disorders. Technological advancement has considerably simplified both the procedure and the interpretation of data obtained, and there is currently reasonable consensus as to the parameters that best discriminate between physiological and pathological gastroesophageal reflux. There remains a need for internationally agreed definitions and standards, particularly with regard to calculation of these parameters, which would improve comparability of future research studies from different centers. Clinical applications of the technique have increased with our enhanced knowledge of the protean clinical manifestations of reflux disease. The advent of potent pharmacotherapy and the recognition of a need for ongoing treatment in many patients will ensure that the most sensitive test for the diagnosis of gastroesophageal reflux disease will remain an essential part of the investigation of upper gastrointestinal symptoms.

Heightened visceral sensation in functional gastrointestinal disease is not site-specific. Evidence for a generalized disorder of gut sensitivity.

Alteration in visceral sensation locally at the site of presumed symptom origin in the gastrointestinal tract has been proposed as an important etiopathological mechanism in the so-called functional bowel disorders. Patients presenting with one functional gastrointestinal syndrome, however, frequently have additional symptoms referable to other parts of the gut, suggesting that enhanced visceral nociception may be a panintestinal phenomenon. We measured the sensory thresholds for initial perception (IP), desire to defecate (DD), and urgency (U) in response to rectal balloon distension, and the thresholds for initial perception and for discomfort in response to esophageal balloon distension in 12 patients with irritable bowel syndrome (IBS) and 10 patients with functional dyspepsia (FD), in comparison with healthy controls. As expected, IBS patients exhibited lower rectal sensory thresholds than controls (P < 0.0001), but in addition had significantly lower sensory thresholds for both perception and discomfort evoked by balloon distension of the esophagus (mean +/- SEM: 8.8 +/- 1.3 ml vs 12.1 +/- 1.5 ml (P < 0.05) and 12.2 +/- 1.4 ml vs 16.4 +/- 1.4 ml (P < 0.02) respectively. Patients with FD showed similarly enhanced esophageal sensitivity, with thresholds for perception and discomfort of 8.1 +/- 0.9 ml (P < 0.02), and 10.1 +/- 1.0 ml (p < 0.001), respectively, but were also found to have sensory thresholds for rectal distension similar to those observed in the IBS group, significantly lower than in controls: IP 45.0 +/- 17.6 vs 59.3 +/- 1.5 ml (P < 0.001), DD 98.0 +/- 17.9 vs 298.7 +/- 9.0 ml (P < 0.0001), U 177.2 +/- 25.4 vs 415.1 +/- 12.6 ml (p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Lowered oesophageal sensory thresholds in patients with symptomatic but not excess gastro-oesophageal reflux: evidence for a spectrum of visceral sensitivity in GORD.

Some patients undergoing ambulatory oesophageal pH monitoring to investigate symptoms suggestive of gastro-oesophageal reflux disease (GORD) are found to have oesophageal acid exposure within the physiological range but show a close correlation between their symptoms and individual reflux episodes. It is suggested that these patients might exhibit enhanced oesophageal sensation, akin to the heightened perception of both physiological and provocative stimuli in the gut that has been described in patients with functional gastrointestinal disorders. This study tested the hypothesis by measuring the sensory thresholds for oesophageal balloon distension and discomfort in 20 patients with symptoms of GORD, in whom ambulatory pH monitoring had shown normal acid exposure times, but in whom the symptom index for reflux events was 50% or greater, and compared these with 15 healthy volunteer controls, and with control groups with confirmed excess reflux. The study group showed lower thresholds both for initial perception of oesophageal distension, and for discomfort, compared with healthy controls (median ml (range)); 7.5 (2-19) v 12 (6-30) (p = 0.002) and 10 (5-20) v 16 (8-30) (p < 0.0001), respectively. Sensory thresholds in the study group were also significantly lower than in patients with excess reflux, and than patients with Barrett's oesophagus, who also exhibited significantly higher sensory thresholds than healthy controls. No differences in sensory thresholds for somatic nerve stimulation were found between the study group and health controls. The results show a spectrum of visceral sensitivity in GORD, with enhanced oesophageal sensation in patients with symptomatic but not excess gastro-oesophageal reflux, suggesting that their symptoms result from a heightened perception of normal reflux events.

Clinical characteristics and natural history of symptomatic but not excess gastroesophageal reflux.

Esophageal pH monitoring in patients with gastroesophageal reflux symptoms identifies some who have normal esophageal acid exposure but nevertheless a convincing correlation between symptoms and those reflux events that do occur. These patients may exhibit enhanced sensory perception of physiological reflux. Little is known about the natural history of reflux symptoms in this group, which in our experience comprises up to 6% of those referred for diagnostic pH monitoring. We have therefore followed up by postal questionnaire 70 patients whose initial pH study had demonstrated normal acid exposure but a symptom index > or = 50% and 58 patients found to have excess reflux, for a median of 4.4 and 6.5 years, respectively. The presenting character and frequency of symptoms and endoscopic and manometric findings were similar in the two groups. At review overall symptom frequency had improved (P < 0.01) for both groups similarly. However, 87% of those with normal acid exposure and 79% of those with excess reflux remained symptomatic, 53% and 47%, respectively, recording their symptoms to be the same or worse than at original presentation, despite over 60% in each group continuing to take regular medication. Only six patients in each group were asymptomatic and receiving no therapy at the time of review. The results demonstrate that patients with symptomatic but not excess gastroesophageal reflux constitute a significant clinical problem. Both the persistence of their symptoms and their requirement for therapy are similar to that observed in "genuine" refluxers.

The effect of ethanol on one-carbon metabolism: increased methionine catabolism and lipotrope methyl-group wastage.

Deficiency of choline and methionine produces hepatic steatosis similar to that seen with ethanol, and supplementation with these lipotropes can prevent ethanol-induced fatty liver. These effects are thought to occur through alterations in membrane phospholipid metabolism, but the mechanism whereby this occurs and the precise nature of the changes brought about by ethanol in the interactions of choline and methionine metabolism remain unclear. Through the known effects on hepatic glutathione (which requires as a precursor a product of methionine catabolism), ethanol might affect hepatic one-carbon metabolism, which requires the participation of both methionine and choline in the transfer of methyl groups. This has been investigated with a radiorespirometric technique to assess the in vivo oxidation of the methyl groups of lipotropes and their intermediates in ethnaol- and control-fed rats. Enzyme activities of one-carbon transfer reactions and the hepatic levels of methionine and alpha-aminobutyrate, an end product of methionine catabolism, have been measured. The effect of ethanol feeding on hepatic S-adenosylmethionine and S-adenosylhomocysteine has also been assessed. Ethanol increases the oxidation to carbon dioxide of the methyl group of methionine by a factor of 2.9 (p = 0.002) and produces a 3.6-fold (p = 0.0001) accumulation of alpha-aminobutyrate, indicating a marked increase in methionine catabolism. Hepatic methionine levels are unchanged by ethanol, however, and this may be explained by a dramatic increase in the turnover of the methyl groups of choline and betaine in response to ethanol (times 3.6 and 4.2, respectively, p < 0.003), suggesting greatly increased use of the choline oxidation pathway to remethylate homocysteine through betaine homocysteine methyltransferase.(ABSTRACT TRUNCATED AT 250 WORDS)

Interaction of positively-charged liposomes with blood: implications for their application in vivo.

Liposomes with positively-charged lipid components have previously demonstrated efficacy in animal models for human diseases, and are currently being evaluated in human clinical studies. Cationic lipids can improve entrapment efficiency of drugs and other substances which are negatively charged, and facilitate penetration of biological membranes in vitro, e.g. in transfection. However, toxic effects have also been reported for positively-charged liposomes containing stearylamine. In this report we have examined gross interactions between plasma components or erythrocytes with cholesterol-rich SUV composed of PC or DPPC and having 0-50 mol% of phospholipid replaced with positively-charged stearylamine, DOTMA, or BisHOP. Plasma interactions observed included increased turbidity of the usually clear stroma and/or formation of a clot-like mass. At plasma concentrations of 0.25 mumol/ml or more, the extent of plasma interactions depended upon the concentration of positive charge, the charge density of cationic lipid initially present in the liposomes, and to a lesser degree, the nature of the lipid providing the positive charge. At liposomal positive charge concentrations of greater than 0.5 mumol/ml plasma, stearylamine provoked a strong increase in plasma turbidity, whereas liposomes incorporating DOTMA or BisHOP provoked a strong clotting response. Some hemolysis of erythrocytes in vitro occurred on interaction with cationic liposomes where positive charge was contributed by DOTMA or stearylamine, but not BisHOP. Implications for the clinical use of liposomes containing cationic lipids, is discussed.