Effect of an indwelling nasogastric tube on gastric emptying rates of liquids in horses.
ABSTRACT To evaluate the effect of an indwelling nasogastric tube on gastric emptying of liquids in horses.
9 healthy adult horses.
A randomized block crossover design was used. For treatment group horses, a nasogastric tube was placed and 18 hours later, acetaminophen was administered; the nasogastric tube remained in place until the experiment was complete. For control group horses, a nasogastric tube was passed into t stomach, acetaminophen was administered, and the nasogastric tube was removed immediately. Serial blood samples were collected 15 minutes before and after administration of acetaminophen. Serum concentration of acetaminophen was determined by use of fluorescence polarization immunoassay. The variables, time to maximum acetaminophen concentration (Tmax) and the appearance constant for acetaminophen (Kapp), were determined. The values for Kapp and Tmax in horses with and without prolonged nasogastric tube placement were compared.
No significant difference was found in Kapp between horses with and without prolonged nasogastric tube placement; the median difference in Kapp was 0.01 min(-1) (range, -0.48 to 0.80 min(-1). No significant difference was found in Tmax between horses with and without prolonged nasogastric tube placement; the median difference in Tmax was 5 minutes (range, -30 to 50 minutes). Reanalysis of data following the removal of possible outlier values from 1 horse resulted in a significant difference in Tmax between horses with and without prolonged nasogastric tube placement.
Although no clinically important impact of 18 hours of nasogastric intubation was found on gastric emptying in healthy was found among horses.
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ABSTRACT: OBJECTIVE: To determine the effect of gastric distension on intraabdominal pressures (IAP) measured directly from the intraperitoneal space. DESIGN: Prospective, experimental study. SETTING: A university-based equine research facility. ANIMALS: Ten healthy adult horses, 5 males and 5 females. INTERVENTIONS: Intraabdominal pressures were measured through an intraperitoneal cannula zeroed at a height midway between the height of the tuber ishii and point of the shoulder at 6 time points: at rest, after placement of a nasogastric tube, and after instillation of each 5 L increment up to a total of 20 L of water. Simultaneously, mean arterial pressures (MAP) were obtained using a tail cuff, and abdominal perfusion pressures (APP) were calculated using the measured IAP minus the measured MAP. MEASUREMENTS AND MAIN RESULTS: Baseline direct IAP measurements were subatmospheric (-4.5 ± 3.0 cm H2 O). IAPs were not significantly affected by placement of a nasogastric tube (-2.69, 95% CI [-3.24, -2.14], P = 0.4195), but were significantly increased after placement of 5 L (-1.73, 95% CI [-2.28, -1.18], P = 0.0015), 10 L (-0.54, 95% CI [-1.09,0.01], P = 0.0001), 15 L (0.89, 95% CI [0.34, 1.44], P = 0.0001), or 20 L (3.08, 95% CI [2.53, 3.63], P = 0.0001) of water into the stomach. APPs were not significantly different for any volume of fluid infused into the stomach (P = 0.05 for all comparisons). CONCLUSION: IAPs were significantly increased when > 5 L of water was infused into the stomach. These results indicate the need for further research in clinical cases to determine the relationship between gastric pressures and the development of intraabdominal hypertension in horses.06/2013; 23(4). DOI:10.1111/vec.12065
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ABSTRACT: Objective-To determine the response to neostigmine of the contractile activity of the jejunum and pelvic flexure and the effects of a continuous rate infusion (CRI) of neostigmine in horses. Animals-7 adult horses and tissue from 12 adult horses. Procedures-A CRI of neostigmine (0.008 mg/kg/h) or placebo was administered to 6 horses in a crossover study design. Gastric emptying was evaluated by the acetaminophen test. The frequency of defecation and urination and the consistency and weight of feces were recorded throughout the experiment. The effect of neostigmine on smooth muscle contractile activity was evaluated in tissues from the jejunum and pelvic flexure. The effect of neostigmine and acetylcholine after incubation with muscarinic receptor antagonists (atropine and DAU 5884) and an acetylcholinesterase inhibitor (edrophonium) was also investigated in vitro. Results-No difference was observed between neostigmine and placebo for time to reach peak plasma acetaminophen concentration and absorption rate constant. A CRI of neostigmine increased fecal production and frequency of urination. Neostigmine induced a dose-dependent increase of contractile amplitude in jejunum and pelvic flexure muscle strips. Incubation of muscle strips with atropine and DAU 5884 inhibited the response to acetylcholine and neostigmine. Incubation of smooth muscle strips from the jejunum with edrophonium increased the response to acetylcholine and had no effect on the response to neostigmine in vitro. Conclusions and Clinical Relevance-A CRI of neostigmine increased fecal production and urination frequency in horses. A CRI of neostigmine did not decrease gastric emptying. Neostigmine stimulated contractile activity of jejunum and pelvic flexure smooth muscle strips in vitro.American Journal of Veterinary Research 04/2013; 74(4):579-88. DOI:10.2460/ajvr.74.4.579 · 1.21 Impact Factor
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ABSTRACT: The objective of this study was to collect gastric contents from conscious horses via naso-gastric (NG) intubation to facilitate the study of the microbial ecosystem of the equine stomach. Six healthy Arabian horses (from 3 to 5 years old) were used according the following procedure. Two hours after the morning feeding, horses were sedated and restrained for NG intubation. A video-endoscope passed through a NG tube was used to position the NG tube in contact with the digesta. The video-endoscope was removed, the digesta were aspirated through the NG tube and collected. Each horse was sampled two times on 2 days according to the protocol. Volume, pH, temperature, dry matter (DM), total anaerobes and lactobacilli microbial populations, volatile fatty acids (VFA), ammonia (NH3), d-glucose and d-/l-lactate concentrations were measured on each sample. Repeatability and reproducibility were calculated for each variable. The technique allowed collection of 190±68ml of gastric contents during each sampling time, which provided the necessary quantities for the various analyses performed. Repeatability of the variables studied ranged from 0.39 for DM up to 0.90 for lactobacilli counts, whereas reproducibility ranged from 0.19 for volume to 0.89 for d-glucose concentration. Paired with classical endoscopic exam for equine gastric ulcer syndrome (EGUS) diagnosis, this collection technique can be easily used by scientists and veterinarians to study the relationship between some major chyme characteristics such as pH, microbial populations and lactate, and the occurrence of diseases such as EGUS.Animal Feed Science and Technology 02/2007; 133(3):259-274. DOI:10.1016/j.anifeedsci.2006.04.004 · 2.09 Impact Factor