Effect of two different pre-anaesthetic omeprazole protocols on gastroesophageal reflux incidence and pH in dogs

OBJECTIVES

Gastroesophageal reflux can occur during anaesthesia and may lead to esophagitis and occasionally oesophageal stricture formation. The aim of the study is to assess two omeprazole protocols on gastroesophageal reflux incidence and pH in anaesthetised dogs.

MATERIALS AND METHODS

Fifty-five dogs undergoing elective ovariectomy were randomly assigned to: omeprazole single dose 1 mg/kg orally the evening before anaesthesia (20 dogs), omeprazole two doses 1 mg/kg orally the evening and 3 hours before anaesthesia (15 dogs), and control group that did not receive omeprazole (20 dogs). An oesophageal impedance/pH probe was used to measure gastroesophageal reflux incidence and pH during anaesthesia.

RESULTS

Gastroesophageal reflux was observed in 55% (11/20) of control dogs, 55% (11/20) of dogs receiving omeprazole once and 47% (7/15) of dogs receiving omeprazole twice. The incidence was not statistically significant different between groups. Gastroesophageal reflux pH (mean ± sd) was higher in dogs receiving omeprazole twice (6.3 ± 1.5), when compared to either control dogs (3.8 ± 1.1) or dogs receiving omeprazole once (4.1 ± 1.5). Strongly acidic reflux (pH < 4) was observed in 7% (1/15) of dogs receiving omeprazole twice versus 55% (11/20) and 35% (7/20) of control dogs and dogs receiving omeprazole once, respectively.

CLINICAL SIGNIFICANCE

Omeprazole administered the evening and 3 hours before anaesthesia increased gastroesophageal reflux pH and decreased the incidence of strongly acidic reflux in dogs. A single dose of omeprazole given the evening before anaesthesia had no effect on reflux pH.

Prevalence of portal vein thrombosis detected by computed tomography angiography in dogs

OBJECTIVE

To evaluate dogs with computed tomography angiography of the abdomen for overall prevalence of portal vein thrombosis and prevalence of portal vein thrombosis based on different disease categories. To evaluate dogs with and without portal vein thrombosis for differences in outcome. To compare ultrasound to computed tomographic angiography for identification of portal vein thrombosis.

METHODS

Abdominal computed tomography angiography of 223 client-owned animals was reviewed for evidence of portal vein thrombosis. Based on medical records, dogs were assigned to disease categories: (1) liver disease; (2) non-hepatic neoplasia; (3) pancreatitis; (4) infectious disease; (5) immune-mediated disease; (6) other; (7) multiple diseases. Different categories were compared for the prevalence of portal vein thrombosis. Outcome was evaluated in dogs with and without portal vein thrombosis. Ultrasound reports were reviewed to determine the detection of thrombosis on ultrasound.

RESULTS

Twenty-eight dogs (13%) had portal vein thrombosis. The pancreatitis category contained the highest percentage of portal vein thrombosis among different categories (eight of 19; 42%). There was a similar outcome between dogs with and without portal vein thrombosis. Of 21 dogs with portal vein thrombosis that had ultrasound performed, ultrasound detected thrombosis in four of 21 (19%) cases.

CLINICAL RELEVANCE

In this study, portal vein thrombosis prevalence was higher in dogs with pancreatitis compared to dogs with liver disease, non-hepatic neoplasia and other abdominal or systemic disease. The portal system should be carefully evaluated with imaging in dogs with pancreatitis. As compared to ultrasound, CT angiography is the imaging method of choice for detection of portal vein thrombosis in dogs.

Evaluation of gastric motility in nine dogs before and after prophylactic laparoscopic gastropexy: a pilot study

BACKGROUND

The purpose of this study was to evaluate the effect of a prophylactic laparoscopic gastropexy on gastric motility in healthy large-breed dogs.

METHODS

This was a prospective pilot study with nine healthy client-owned dogs. Each dog was its own control. Gastric motility was evaluated before and after laparoscopic gastropexy. Dogs were fed a standard diet three weeks before and after surgery. Gastric motility was measured before and 3 weeks after surgery. A wireless motility capsule (WMC) was used to measure gastric pH, intragastric pressure, temperature, frequency of contractions, motility index (MI) and transit time. Non-parametric statistical analysis was used to compare the paired data. Clients were contacted for follow-up information 2 years postoperatively.

RESULTS

Median frequency of gastric contractions was 1.3 (range, 0.6-1.9 contractions/min) before gastropexy and 1.0 (range, 0.3-2.6 contractions/min) after gastropexy (P = 0.820). Median MI was 49.2 (range, 23.7-96.6) before gastropexy and 28.1 (range, 12.2-148.9) after gastropexy (P = 0.652). Median gastric emptying time was 1140 (range, 486-1230 min) before gastropexy and 1110 (range, 306-2610 min) after gastropexy (P = 0.570). During the hour before the WMC passed through the pylorus, median MI was 72.2 (range, 48.2-549.3) before gastropexy and 52.9 (range, 15.20-322.8) after gastropexy (P = 0.734), and frequency of contractions was 1.1 (range, 0.9-4.1 contractions/min) before gastropexy and 1.2 (range, 0.5-3.0 contractions/min) after gastropexy (P = 0.652).

CONCLUSION

Motility in the stomach did not change in healthy dogs after prophylactic laparoscopic gastropexy. We conclude that preventive laparoscopic gastropexy does not induce gastroparesis.

The effect of intravenous diazepam on solid phase gastric emptying in normal cats

Intravenous diazepam has been advocated as an appetite stimulant in anorexic cats. Diazepam has also been used to stimulate the intake of radiographic contrast medium-food mixture to determine the gastric emptying time of a solid meal. Diazepam has been suspected to delay gastric emptying in cats. One study found diazepam combined with valium to have little effect on gastric transit times in cats while diazepam alone accelerates gastric emptying in humans. The purpose of this study was to determine if diazepam influences gastric emptying times in normal cats. The gastric emptying half-time of solid food in normal, non-diazepam treated cats has been previously determined using a scintigraphic technique using 99mTc-sulfur colloid to radiolabel solid dry food. The median gastric emptying half-time was 2.3 hours and the mean meal size was 16.1 grams. Gastric emptying half-times were determined in this study using diazepam as an appetite stimulant. The median gastric emptying half-times of diazepam treatment groups given both a 16.1 gram meal and a large meal were both significantly longer than the normal non-treated group (P < 0.05). Solid phase gastric emptying is therefore significantly delayed when diazepam is used as an appetite stimulant, irrespective of the volume of the meal.

Diurnal change of blood count analytes in normal subjects

Short-term, within one 24-hour day (diurnal period) within-person changes of the principal blood count analytes in healthy subjects were studied at three major institutions. The results from each test site were indistinguishable and were therefore combined to make a database of 96 healthy subjects. Analytical imprecision of each analyte was subtracted from the total observed variation to give true diurnal change. Each analyte showed characteristic changes. As would be expected, cellular properties of erythrocytes, such as MCV (mean cell volume) and MCH (mean cell hemoglobin) showed negligible change. The red cell count, hematocrit, and hemoglobin showed changes that were consistent with fluid balance change. Total white cell count and some differential count components showed major changes that raised questions of the confidence limits of clinical decision levels and the validity of commonly used reference intervals. Platelet count changes were typically less than analytic imprecision, suggesting the need for improvement in this aspect of analyzer performance.

Absolute versus proportional differential leucocyte counts

Comparison of absolute (cells x 10(9)/l) leucocyte differential counts with proportional (percentage) counts from the same stained films demonstrates significant disparities between these two methods of reporting results. Within reference intervals the disparities are modest but become significant in specimens with distributional abnormalities. Although neither method of reporting is formally espoused in this communication, it is suggested that use of the absolute count is more likely to provide diagnostic support.

Oxidant injury to hepatic mitochondria in patients with Wilson's disease and Bedlington terriers with copper toxicosis

BACKGROUND/AIMS

Copper overload leads to liver injury in humans with Wilson's disease and in Bedlington terriers with copper toxicosis; however, the mechanisms of liver injury are poorly understood. This study was undertaken to determine if oxidant (free radical) damage to hepatic mitochondria is involved in naturally occurring copper toxicosis.

METHODS

Fresh liver samples were obtained at the time of liver transplantation from 3 patients with Wilson's disease, 8 with cholestatic liver disease, and 5 with noncholestatic liver disease and from 8 control livers. Fresh liver was also obtained by open liver biopsy from 4 copper-overloaded and 4 normal Bedlington terriers and from 8 control dogs. Hepatic mitochondria and microsomes (humans only) were isolated, and lipid peroxidation was measured by lipid-conjugated dienes and thiobarbituric acid-reacting substances. In humans, liver alpha-tocopherol content was measured.

RESULTS

Lipid peroxidation and copper content were significantly increased (P < 0.05) in mitochondria from patients with Wilson's disease and copper-overloaded Bedlington terriers. More modest increases in lipid peroxidation were present in microsomes from patients with Wilson's disease. Mitochondrial copper concentrations correlated strongly with the severity of mitochondrial lipid peroxidation. Hepatic alpha-tocopherol content was decreased significantly in Wilson's disease liver.

CONCLUSIONS

These data suggest that the hepatic mitochondrion is an important target in hepatic copper toxicity and that oxidant damage to the liver may be involved in the pathogenesis of copper-induced injury.

Continuum analysis method applied to blood count reference intervals

Conventional methods for extracting reference values from a sample of a purported normal population have a tendency to include some paranormal individuals and to obscure the existence of marginal or subclinical disorders. The suggestion is offered of defining the normal range of an analyte by extrapolation of the portion of its dispersion that fits a continuum. The method softens the present dichotomous character of the reference range. It narrows the normal range of some hematology parameters, suggesting that some paranormal individuals are excluded.

A method for the independent assessment of the accuracy of hematology whole-blood calibrators

An independent assessment of the accuracy with which a large manufacturer assigned values to hematologic calibrators was performed. Data were collected from 1,767 hospitals and clinics distributed over North America. Statistical analysis of the mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration of these patient data confirmed the accuracy of the values for hemoglobin, erythrocyte count, hematocrit, and erythrocyte indices for the calibrators manufactured and released during a 9-month period. This approach proved both workable and effective in detecting inaccuracies of less than 1%. Few technologist-users have the time or the equipment to verify independently the accuracy of hematologic calibrators. The manufacturers should perform ongoing, independent assessments of the accuracy of their products. The statistical analysis of patient data provides manufacturers with a suitable method.

Hepatozoon sp. in wild carnivores in Texas

Twelve coyotes (Canis latrans), three bobcats (Lynx rufus) and six ocelots (Felis pardalis) from the Gulf Coast of Texas were infected with Hepatozoon sp. The geographic distribution of infected wild animals coincides with the highest prevalence of Hepatozoon canis infection in domestic dogs for which the wild species may act as a reservoir.