Risk factors associated with development of postoperative ileus in horses

Factors associated with development of post-operative reflux in horses with large colon volvulus and association with complications and outcomes

BACKGROUND

Post-operative reflux (POR) is rare following large colon volvulus (LCV) but does occur despite the absence of a small intestinal lesion. The prevalence, risk factors and association with survival of POR after LCV are currently unknown.

OBJECTIVES

To determine the prevalence of POR in horses with an LCV and its association with survival. A further objective was to assess factors which may predict POR. The hypothesis was that horses with POR following LCV surgery have a worse outcome for survival compared to those without POR.

STUDY DESIGN

A retrospective cross-sectional study.

METHODS

Clinical data of client owned horses which underwent colic surgery at a single UK referral hospital between 2008 and 2021, where LCV was the primary finding, were retrieved from hospital records. Statistical analyses included chi-squared, t-tests and odds ratios (ORs). Horses with concurrent lesions, and those that did not survive past anaesthetic recovery, were excluded from analysis. POR was defined as ≥2 L of gastric reflux on at least one occasion.

RESULTS

A total of 128 horses were included in the study, 23 of which had POR (18%). Overall survival to hospital discharge was 86%, 95% in the non-POR and 44% in the POR group. Horses with POR were less likely to survive to discharge than those without (OR = 26, 95% confidence interval [CI] [7.68-88.0], p < 0.001), and less likely to be alive 3 years after surgery (OR = 13.4, 95% CI [2.78-64.8], p < 0.001).

MAIN LIMITATIONS

Due to the retrospective study design, full data sets were not available for every case because clinical records were incomplete or, at that time, certain tests were not performed or clinical variables were not measured.

CONCLUSIONS

POR in LCV cases is a negative prognostic indicator for survival.

The Effects of Antimicrobial Protocols and Other Perioperative Factors on Postoperative Complications in Horses Undergoing Celiotomy: A Retrospective Analysis, 2008-2021

Recognition of antimicrobial resistance in equine practice has increased over the past decade. The objective of this study was to provide an updated retrospective review of antimicrobial regimens in one tertiary referral hospital and to evaluate the association with postoperative complications. A secondary objective was to evaluate other perioperative factors including surgical procedure, anesthetic and recovery parameters, and the effect of perioperative medications on complications and outcomes. A computerized search of medical records was performed to identify horses undergoing exploratory celiotomy from 1 January 2008 to 31 December 2021. A total of 742 celiotomies were performed (608 completed, 134 terminated intraoperatively). Factors recorded were evaluated using logistic regression for the presence of either incisional infection, postoperative ileus, or other complications postoperatively. Antimicrobial type or timing (pre-, intra-, or postoperative) were not associated with decreased risk of incisional infection or postoperative ileus; however, the duration of NSAID use was positively associated with incisional infection (OR 1.14 per day). Lidocaine and alpha-2-agonist administration postoperatively were also associated with increased incidence of postoperative ileus (OR 21.5 and 1.56, respectively). Poor recovery quality (OR 4.69), the addition of other antimicrobials besides penicillin/gentamicin postoperatively (OR 3.63), and an increased number of different NSAID classes used (OR 1.46 per additional) were associated with other complications. Implementation of enterotomy was associated with decreased risk of other complications (OR 0.64). These findings provide an updated summary of factors associated with postoperative complications in horses undergoing celiotomy.

Effects of Bit Chewing on Gastric Emptying, Small Intestinal Transit, and Orocecal Transit Times in Clinically Normal Horses

Ileus is a common life-threatening problem in horses, and currently available treatments may be ineffective. The purpose of this study was to determine whether bit chewing, a form of sham feeding, decreases the gastric emptying time (GET), small intestinal transit time (SITT), and total orocecal transit time (OCTT) in clinically normal horses in a prospective crossover study. Nine healthy horses were acclimated and fed a standardized diet. Following 24 h of fasting, self-contained video endoscopy capsules and acetaminophen were administered into the stomach via a nasogastric tube. Each horse underwent experimental (bit chewing for 20 min every 6 h) or control (no bit chewing) conditions, with a 3-week minimum washout period between conditions. The horses were enrolled in either part of the study until all video capsules were retrieved and/or 30 days lapsed. The video capsules were recovered from manure, and GET, SITT, and OCTT were determined from a video analysis. Bit chewing significantly decreased OCTT (p = 0.015) compared to the control conditions. Bit chewing decreased GET and SITT, but the differences were not significant. The mean (median) times determined via the video capsule analysis for the bit-chewing conditions were as follows: GET, 2.34 h (2.86 h); SITT, 3.22 h (3.65 h); and OCTT, 5.13 h (6.15 h), and for the control conditions, they were as follows: GET, 3.93 h (5 h); SITT, 3.79 h (4.4 h); and OCTT, 8.02 h (9.92 h). Bit chewing decreased OCTT in healthy horses. Because this segment of the gastrointestinal tract is frequently affected by ileus, bit chewing may be a safe and inexpensive intervention for that condition in horses. Further investigation in clinical patients with ileus is warranted.

Retrospective analysis of postoperative complications following surgical treatment of ileal impaction in horses managed with manual decompression compared to jejunal enterotomy

Objective

The objective of this study was to compare the occurrence of post-operative complications and survival to discharge in horses with ileal impactions resolved by manual decompression compared with jejunal enterotomy.

Animals

A total of 121 client-owned horses undergoing surgical correction of an ileal impaction at three teaching hospitals.

Materials and methods

Data from the medical records of horses undergoing surgical correction of an ileal impaction was retrospectively collected. Post-operative complications, survival to discharge, or post-operative reflux present were evaluated as dependent variables and pre-operative PCV, surgery duration, pre-operative reflux, and type of surgery were evaluated as independent variables. Type of surgery was divided into manual decompression (n = 88) and jejunal enterotomy (n = 33).

Results

There were no significant differences in development of minor complications, development of major complications, presence of post-operative reflux, amount of post-operative reflux, and survival to discharge between horses that were treated with manual decompression and those treated with distal jejunal enterotomy. Pre-operative PCV and surgery duration were significant predictors of survival to discharge.

Conclusions and clinical relevance

This study showed that there are no significant differences in post-operative complications and survival to discharge in horses undergoing distal jejunal enterotomy versus manual decompression for correction of ileal impaction. Pre-operative PCV and duration of surgery were found to be the only predictive factors of survival to discharge. Based on these findings, distal jejunal enterotomy should be considered earlier in horses with moderate to severe ileal impactions identified at surgery.

A retrospective evaluation of the effect of perianesthetic hydromorphone administration on the incidence of postanesthetic signs of colic in horses

OBJECTIVE

To describe the incidence of postanesthetic signs of colic (PASC) in horses and determine if perianesthetic administration of hydromorphone was associated with an increased risk of PASC.

STUDY DESIGN

Retrospective, cohort study.

ANIMALS

A total of 409 horses.

METHODS

Anesthesia and clinical records of horses admitted for various procedures from July 2018 to September 2019 were reviewed. Signs of colic and interventions were recorded up to 48 hours after anesthesia. A binomial logistic regression model was used to evaluate the association between the type of surgery, administration of hydromorphone, the duration of anesthesia and the incidence of PASC.

RESULTS

Overall, 25 (6.1%) horses developed PASC within 48 hours of general anesthesia. Of 60 horses that underwent colic surgery, 16 (26.7%) developed PASC. Of 349 horses that underwent noncolic procedures, nine (2.6%) developed PASC. Thus, the incidence of PASC was higher in horses that underwent colic surgery than in horses that underwent noncolic procedures [odds ratio (OR) = 13.74 (5.73-32.95)]. No effect of hydromorphone on the incidence of PASC was identified [OR = 1.61 (0.71-3.62)]. Longer procedures (>2 hours) were identified as an independent risk factor for PASC [OR = 4.13 (1.52-11.22)].

CONCLUSIONS

No association between hydromorphone and an increase in the incidence of PASC was identified. Anesthesia for colic surgery and duration of anesthesia were associated with an increased risk of PASC.

CLINICAL RELEVANCE

Hydromorphone did not increase the incidence of PASC in this population.

Small Intestine Ultrasound Findings on Horses Following Exploratory Laparotomy, Can We Predict Postoperative Reflux?

Simple Summary

Postoperative reflux is a well-recognized complication after exploratory laparotomy, particularly in horses that present with small intestine pathology. Even though much has been written about the pathophysiology and management of this postsurgical complication, we could not find a study that describes the monitoring of small intestine appearance after laparotomy via transcutaneous abdominal ultrasound. Therefore, the aim of the study was to provide clinical evidence of ultrasound finds in 58 horses over three days post exploratory laparotomy. The results from these exams were compared to the abdominal ultrasounds of 20 horses undergoing general anesthesia for an elective procedure, which were used as a control group. Differences were found between horses with versus without small intestinal pathology. Horses operated on because of large colon pathology had similar ultrasound findings to the control group during the postoperative period. In contrast, horses that were presented with small intestinal pathology had more visible small intestine loops, increased loop diameter, and wall thickness, before and after surgery, particularly those cases that had undergone a resection and anastomosis. A quick abdominal ultrasound in horses, during the postoperative period after colic surgery, was a useful method to identify horses with abnormal small intestinal parameters, both pre- and post-surgery. Further investigation as to whether these parameters can be used to predict postoperative reflux (POR) in a larger population is warranted.

Abstract

Postoperative reflux (POR) is a well-recognized complication after colic surgery in horses, particularly when presenting small intestinal pathology. Even though much has been written about the pathophysiology and management of POR, additional clinical studies are needed to better understand and anticipate this complication. The aim of the study was to provide clinical evidence of ultrasound findings in the postoperative period (three days). The study is based on transcutaneous abdominal ultrasounds of the caudoventral abdomen during the postoperative period (three days), in 58 horses, presented for an exploratory laparotomy, and compared to 20 horses that underwent general anesthesia for an elective surgical procedure. Small intestine (SI) images and videos were analyzed for loop number, loop diameter, wall thickness, motility, and echogenic type of loop contents. Ultrasound findings of horses that had a large colon pathology were similar to those of the control group. Interestingly, horses that presented an SI pathology had significantly thicker SI walls, increased loop diameter, slower motility, and hypoechoic contents, particularly in horses that had undergone small intestinal resection and anastomosis. Although the number of horses that developed POR in our study was too small for statistical analysis, they all had the aforementioned ultrasonographic changes. Abdominal ultrasound, during the postoperative period (three days), was a useful method to identify horses with abnormal small intestinal parameters. Further investigation as to whether these parameters can be used to predict POR in a larger population is warranted.

Use of perioperative variables to determine the requirement for repeat celiotomy in horses with postoperative reflux after small intestinal surgery

OBJECTIVE

To determine whether perioperative variables can be used to differentiate a medical vs a surgical reason for postoperative reflux (POR) after small intestinal (SI) surgery in horses.

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Horses >1 year of age that recovered from SI surgery and had POR.

METHODS

Medical records of horses that underwent SI surgery and developed POR from 2009-2015 were reviewed. Surgical reasons for POR were defined as an anastomosis complication, mechanical obstruction, or nonviable intestine identified at repeat celiotomy/necropsy. A medical reason for POR was presumed when the POR improved with medical treatment or when no surgical reasons were identified at repeat celiotomy/necropsy. Perioperative variables were analyzed and used to develop a logistic regression model.

RESULTS

Fifty-one horses had POR after SI surgery. After initial SI surgery, 14 horses had surgical reasons for POR diagnosed at repeat celiotomy or necropsy. Thirty-seven horses were considered to have medical reasons for POR because their POR resolved with medical management or functional ileus was diagnosed at repeat celiotomy/necropsy. A greater volume and a greater duration of POR were not associated with a surgical reason for POR. Rather, a postoperative (PO) fever and the timing of colic in the PO period were associated with a surgical reason for POR.

CONCLUSION

Horses that developed a fever and colic in the PO period after SI surgery were more likely to have a surgical reason for POR.

CLINICAL SIGNIFICANCE

These findings may provide guidance for clinicians when they are making decisions about repeat celiotomy in horses with POR after SI surgery.

Serum amyloid A and plasma fibrinogen concentrations in horses following emergency exploratory celiotomy

BACKGROUND

Acute-phase proteins may help assess the nature and severity of lesions and outcome in horses undergoing colic surgery.

OBJECTIVES

To compare serum amyloid A and plasma fibrinogen concentrations ([SAA] and [fibrinogen]) in the immediate post-operative period after exploratory celiotomy and determine their value in assessment of post-operative complications and survival to discharge.

STUDY DESIGN

Observational study.

METHODS

This study included horses over 1 year of age undergoing exploratory celiotomy. Surgical procedures, lesions, post-operative care, complications and survival to discharge were recorded. [SAA] and [fibrinogen] were measured prior to surgery and 5 days post-operatively. Statistical analyses included Yate's Chi-square test, linear mixed effects model, Mann-Whitney U test and logistic regression.

RESULTS

Of 300 horses, 52.0% developed post-operative complications and 83.7% survived to discharge, with significantly reduced chance of survival in horses that developed post-operative complications (P<0.01). Median [SAA] at days 1, 2, 3, 4 and 5 and median [fibrinogen] at days 3, 4 and 5 were significantly different between horses that did and did not develop post-operative complications (P<0.05). Median [SAA] at days 1, 4 and 5 were significantly different between horses that did and did not survive to discharge (P<0.05). Logistic regression revealed post-operative complications to be associated with strangulating lesions (OR 2.35, 95% confidence interval [CI] 1.41-3.91, P≤0.001) and higher [fibrinogen] at admission (OR 1.21, 95% CI 1.00-1.45, P<0.05), and survival to discharge to be associated with lower [SAA] at 5 days post-operatively (OR 0.965, 95% CI 0.94-0.99, P = 0.002).

MAIN LIMITATIONS

A large variety of lesions and complications prevented detailed analysis of associations between inflammatory markers, lesions and complications.

CONCLUSIONS

Horses that develop post-operative complications have acute-phase responses of greater magnitudes and durations compared with those that do not develop complications. This is also seen in horses that do not survive to discharge. Measuring [SAA] daily and [fibrinogen] at admission, may help predict the development of post-operative complications.

A retrospective study of fecal output and postprocedure colic in 246 horses undergoing standing sedation with detomidine, or general anesthesia with or without detomidine

OBJECTIVE

To determine time to first passage of feces, total fecal piles and incidence of colic in the first 24 hours postprocedure in horses undergoing standing sedation with detomidine, or general anesthesia with or without detomidine.

STUDY DESIGN

Retrospective cohort study.

ANIMALS

A total of 246 horses.

METHODS

Records of all horses that underwent standing sedation or general anesthesia between December 2012 and March 2016 were reviewed. Horses aged <6 months, admitted for colic or cesarean section, with inadequate data, and those not administered xylazine and/or detomidine were excluded. Records included patient signalment, fasting duration, procedure performed, drugs administered, time to first feces, number of fecal piles during 24 hours postprocedure and mention of colic. Chi-square, Fisher's exact and Tukey's post hoc comparison tests were used. Parametric data were reported as mean ± standard deviation with significance defined as p <0.05.

RESULTS

In total, 116 and 57 horses underwent general anesthesia without detomidine (group GA) and with detomidine (group GA-D), respectively, and remaining 73 horses underwent standing sedation with detomidine (group S-D). Detomidine dose was significantly higher in group S-D than in group GA-D. Time to first feces was longer (7.1 ± 4.2 hours), and group S-D horses passed one fewer fecal pile (6.3 ± 2.4) than group GA horses. There was no interaction between detomidine treatment and preprocedure food withholding and the time to first feces or the number of fecal piles in the first 24 hours postprocedure. Overall, seven horses (2.8%) showed signs of colic (five, one and one in GA, GA-D and S-D, respectively).

CONCLUSIONS AND CLINICAL RELEVANCE

Detomidine administration, as part of an anesthetic protocol or for standing sedation procedures, should not be expected to contribute to postprocedural colic.

Clinical findings associated with development of postoperative reflux and short-term survival after small intestinal surgery in geriatric and mature nongeriatric horses

OBJECTIVE

To determine risk factors, especially age, associated with postoperative reflux (POR; >2 L of reflux present upon intubation), high-volume POR (≥20 L in 24 hours), and short-term outcome after small intestinal (SI) surgery.

STUDY DESIGN

Retrospective case-control study.

SAMPLE POPULATION

Horses aged ≥16 years (geriatric; range, 16-30; n = 44) and <16 years (mature; range, 2-15; n = 39) with an SI surgical lesion that survived general anesthesia and did not have a second exploratory celiotomy during the same visit.

METHODS

Medical records (2009-2015) were reviewed; perioperative variables were evaluated for associations with outcomes by using multivariable logistic regression.

RESULTS

Postoperative reflux was associated with an increasing packed cell volume at admission (odds ratio [OR], 1.08; 95% CI, 1.00-1.16; P = .042) and presence of nasogastric reflux at admission (OR, 4.61; 95% CI, 1.3-15.69; P = .014). High-volume POR was associated with an increasing glycemia at admission (OR, 1.19; 95% CI, 1.01-1.40; P = .041), presence of nasogastric reflux at admission (OR, 10.05; 95% CI, 2.21-45.74; P = .003), and SI resection (OR, 10.52; 95% CI, 1.81-61.25; P = .009). Increasing surgical time (OR, 2.50; 95% CI, 1.16-5.29; P = .019) and high-volume POR (OR, 6.37; 95% CI, 2.12-19.12; P = .001) were associated with nonsurvival.

CONCLUSION

Age, considered as both a continuous variable and a categorical variable, was not associated with the development of POR, high-volume POR, or nonsurvival.

CLINICAL SIGNIFICANCE

Age does not influence the occurrence of POR and should not negatively impact an owner's decision to pursue surgery in aged horses.

Retrospective evaluation of the effect of intravenous fluid administration on development of postoperative reflux in horses with colic (2004-2012): 194 horses

OBJECTIVE

To evaluate the role of intravenous fluid volume and electrolyte supplementation on the development of postoperative reflux (POR) in horses undergoing celiotomy for colic.

DESIGN

Case-control study spanning 2004-2012 for horses undergoing celiotomy for colic.

SETTING

University teaching hospital.

ANIMALS

Sixty-seven client-owned horses >1 year of age with POR were each matched to 2 controls with similar surgical lesions that did not demonstrate POR.

MEASUREMENTS AND MAIN RESULTS

Survival was significantly lower in cases (65.7%) than controls (96.1%). Factors found to be associated with POR included decreased net fluid volume administered on day 1 postoperatively, increased age, and performing a resection and anastomosis. Mean time until onset of POR was 20.4 hours postoperatively. PCV was significantly higher immediately following surgery and at 24 hours postoperatively in horses that developed POR compared with matched controls. There was no association between electrolyte values at presentation or administration of potassium, calcium, or magnesium in the postoperative period and the subsequent development of reflux.

CONCLUSIONS

In the perioperative period, IV fluid volume overload and electrolyte abnormalities were not contributing factors in the development of POR in this population of surgical colic patients. Close postoperative monitoring with consideration and correction of pre- and postoperative fluid deficits is recommended.

Effects of hyaluronate-carboxymethylcellulose membranes on the clinical outcome of horses undergoing emergency exploratory celiotomy

OBJECTIVE

To determine the influence of hyaluronate-carboxymethylcellulose (HA-CMC) membranes applied to intestinal anastomoses or enterotomies on postoperative complications after emergency exploratory celiotomy.

STUDY DESIGN

Multicenter retrospective case-controlled series.

ANIMALS

Adult horses (59 in the HA-CMC group and 91 controls).

METHODS

Medical records from 4 referral hospitals were searched for horses ≥1 year of age, treated between 2008 and 2014 with emergency exploratory celiotomy, and surviving at least 24 hours postoperatively. Horses receiving repeat celiotomy during the same hospitalization were excluded. Horses who received HA-CMC were matched with controls who did not receive HA-CMC but had similar intestinal lesions and procedures at the same referral hospital. Postoperative complications (colic, nasogastric reflux, fever, incisional infection, and septic peritonitis), duration of hospitalization, and survival were compared between groups. Data were compared between horses by t test, Wilcoxon signed rank test, and χ² test.

RESULTS

The volume of nasogastric reflux at admission (P = .02) and the duration of administration of lidocaine after surgery (P = .02) were greater in horses with HA-CMC membranes than in controls. No difference in postoperative complications or survival was detected between groups: 48 of 59 (81%) horses treated with HA-CMC survived until discharge from the hospital compared with 80 of 91 (88%) horses in the control group (P = .27). Fifteen of 21 horses treated with HA-CMC and 30 of 43 horses in the control group survived >12 months after hospital discharge.

CONCLUSION

Application of HA-CMC membranes to anastomoses or intestinal incisions did not influence postoperative complications or survival after emergency celiotomy compared with controls.

CLINICAL SIGNIFICANCE

The safety and efficacy of HA-CMC membrane application to intestinal sites during colic surgery in horses is equivocal.

Interval prevalence of and factors associated with colic in horses hospitalized for ocular or orthopedic disease

OBJECTIVE To determine interval (1-year) prevalence of and factors associated with colic in horses hospitalized for ocular or orthopedic disease. DESIGN Cross-sectional study. ANIMALS 105 horses with ocular disease and 197 horses with orthopedic disease admitted to a veterinary teaching hospital between July 1, 2011, and June 30, 2012. PROCEDURES Medical records were reviewed to determine whether colic (abnormal behavior prompting abdominal palpation per rectum or nasogastric intubation) was observed during hospitalization. Data were collected on putative risk factors for colic, including reason for admission, signalment, and medical or surgical interventions received. RESULTS No significant difference in interval prevalence of colic was identified between horses with ocular disease (8/105 [8%]) or orthopedic disease (9/197 [5%]). However, horses with ocular disease differed significantly from other horses in median age (10 vs 3 years, respectively); proportions of sexually intact males (3% vs 30%), Thoroughbreds (28% vs 62%), and those receiving general anesthesia (65% vs 80%); and median duration of hospitalization (3 vs 2 days). For every 1 mg/kg increase in daily NSAID dose, the odds of colic increased by 98%. No difference between groups was identified in median duration of colic (1 day), hospitalization (7 vs 3 days), or systemic NSAID administration (7 vs 5 days). Colic in both groups resolved with medical management for all but 1 horse with ocular disease. CONCLUSIONS AND CLINICAL RELEVANCE Horses hospitalized for ocular disease were at no greater odds for colic than were horses hospitalized for orthopedic disease. Medical management of colic appeared adequate for most horses.

Investigation of perioperative and anesthetic variables affecting short-term survival of horses with small intestinal strangulating lesions

OBJECTIVE

To determine if preoperative and intraoperative physiologic variables, and surgical factors correlate with survival to anesthetic recovery or hospital discharge, repeat celiotomy, and postoperative nasogastric intubation (NGT) in horses undergoing exploratory celiotomy for small intestinal (SI) strangulating lesions.

STUDY DESIGN

Retrospective case series.

ANIMALS

Horses that had surgical correction of SI strangulating lesions (n = 258).

METHODS

Medical records (January 2000-December 2014) of horses that had surgical correction of SI strangulating lesions were reviewed. Data collection included signalment, preoperative physical examination variables, hematologic values, presence of gastric reflux, peritoneal fluid analysis, intraoperative physiologic variables, intraoperative findings/treatments, and arterial blood gas values. Risk factors for survival to anesthetic recovery and hospital discharge were determined using exact logistic regression.

RESULTS

Survival to anesthetic recovery was 76% and survival to discharge after anesthetic recovery was 79%. The difference between abdominal and peripheral lactate concentrations and intraoperative tachycardia were associated with not surviving to anesthetic recovery or hospital discharge. Intraoperative hypotension, hypocapnia, and low intraoperative packed cell volume (PCV) were negative predictors of survival to anesthetic recovery. Low intraoperative PCV was also associated with NGT postoperatively. Performing resection-anastomosis and jejunocecostomy were associated with repeat celiotomy and with not surviving to hospital discharge.

CONCLUSION

Several hematological and cardiorespiratory variables show good correlation with short-term survival in horses undergoing surgery for SI strangulating lesions. These variables are easily measured and could be useful for prognosticating survival in horses presenting with SI strangulating lesions.

Effects of Single-Dose Prucalopride on Intestinal Hypomotility in Horses: Preliminary Observations

Abnormalities of gastrointestinal motility are often a challenge in horses; however, the use of prokinetic drugs in such conditions must be firmly established yet. For this reason we carried out a preliminary study on the effects of prucalopride on intestinal motor activity of horses with gut hypomotility. The effect of prucalopride per os by oral dose syringe (2 mg/100 kg body weight) was assessed by abdominal ultrasound (evaluating duodenal, cecal, and colonic motor activity) in six horses with gut hypomotility. After administration of prucalopride, a significant increase of contractile activity was found in the duodenum at 30 minutes (p = 0.0005), 60 minutes (p = 0.01) and 90 minutes (p = 0.01), whereas in the cecum and in the left colon the increase was only present at 60 minutes (p = 0.03, and p = 0.02, respectively). No changes from baseline heart and respiratory rate or behavior side effects were observed after administration of the drug and throughout the observation period. Prucalopride may be a useful adjunct to the therapeutic armamentary for treating hypomotile upper gut conditions of horses. Dosing information is however needed to establish its actual clinical efficacy and its proper effects on the large bowel in these animals.

Scoring System for Multiple Organ Dysfunction in Adult Horses with Acute Surgical Gastrointestinal Disease

Background

The prevalence of multiple organ dysfunction syndrome (MODS) in horses with acute surgical gastrointestinal (GI) disease is unknown. Currently, there are no validated criteria to confirm MODS in adult horses.

Objectives

To develop criteria for a MODS score for horses with acute surgical colic (MODS SGI) and evaluate the association with 6‐month survival. To compare the MODS SGI score with a MODS score extrapolated from criteria used in people (MODS EQ).

Animals

Adult horses that required exploratory laparotomy (n = 62) for colic. Healthy adult horses undergoing elective surgical procedures (n = 12) established the reference range of some variables.

Methods

Prospectively, a MODS SGI score was developed based on organ‐specific criteria established from a literature review, data collection, and clinical judgment. Data for scoring each horse were collected on Days 1 and 2 postoperatively. Horses were scored retrospectively using both scoring criteria. The prognostic performance of the MODS SGI score and its overall performance compared with the MODS EQ score were assessed with receiver operating characteristic (ROC) curve analysis.

Results

The MODS SGI score had excellent performance for predicting 6‐month survival with an area under the ROC curve (AUC) of 0.95 (95% CI: 0.87–0.99). The AUC for the MODS SGI score was significantly higher than the MODS EQ (AUC: 0.76; 0.63–0.86).

Conclusions and Clinical Importance

The MODS SGI score predicts 6‐month survival from discharge in horses with acute surgical colic. The MODS SGI score performed better than a score extrapolated from human scoring systems.

Assessment of systemic inflammation by time-trends of blood granulocyte count and plasma myeloperoxidase and elastase concentrations following colic surgery in horses

OBJECTIVE

To determine changes in blood granulocyte counts and in plasma myeloperoxidase (MPO) and elastase (ELT) concentrations in surgical colic cases, and to determine the relationship between these changes and the surgical procedure performed, occurrence of postoperative ileus, and final outcome.

DESIGN

Prospective clinical study conducted over a 12-month period.

SETTING

University teaching hospital.

ANIMALS

Fifty-three horses undergoing emergency laparotomy and surviving at least 12 hours postoperatively.

INTERVENTIONS

Blood samples were taken before surgery, during surgery, at the recovery from anesthesia, and then serially until the 150th hour after the first blood sampling. Granulocyte counts were performed by an automated cell hematology analyzer. Specific ELISAs were performed for the MPO and ELT measurements. Mixed models were used to compare the time-trends of the 3 parameters.

MEASUREMENTS AND MAIN RESULTS

Taking all horses together, the time-trends of MPO and ELT were not significantly different from each other, but they were significantly different from the granulocyte time-trend. The type of surgical procedure did not influence the time-trends of the 3 parameters. Significant changes in the granulocyte time-trends were associated with postoperative ileus and outcome. Significant changes in the MPO time-trends were associated with outcome. The ELT time-trends were not influenced by ileus or outcome.

CONCLUSIONS

Granulocyte counts and MPO change over time and are related to the severity of the inflammatory reaction in surgical colic cases. These time-trends may allow evaluation of treatment efficacy in an effort to modulate excessive granulocyte activation and degranulation.

Clinical features and management of equine post operative ileus (POI): Survey of Diplomates of the American Colleges of Veterinary Internal Medicine (ACVIM), Veterinary Surgeons (ACVS) and Veterinary Emergency and Critical Care (ACVECC)

REASONS FOR PERFORMING STUDY

A recent survey of European Colleges (European College of Equine Internal Medicine [ECEIM] and European College of Veterinary Surgeons [ECVS]) revealed the different strategies implemented by, and some of the challenges facing, European clinicians presented with cases of post operative ileus (POI). It was concluded that further comparative analysis of opinions, canvassed from additional colleges of equine veterinary specialism worldwide, would provide valuable additional insight into current POI knowledge on a more global scale.

OBJECTIVES

To report and compare the current strategies favoured by American veterinary specialists when managing POI in horses that underwent emergency colic surgery.

STUDY DESIGN

Cross-sectional survey.

METHODS

Electronic invitations were sent to 814 Large Animal specialists, including 3 colleges: the American College of Veterinary Internal Medicine (ACVIM), American College of Veterinary Surgeons (ACVS) and the American College of Veterinary Emergency and Critical Care (ACVECC).

RESULTS

The response rate was 14% (115/814). The majority of respondents (68%) reported an estimated prevalence range of POI of 0-20%. The presence of reflux on nasogastric intubation was the main criterion used to define POI. A lesion involving the small intestine was considered the main risk factor for POI. Anti-inflammatory drugs, intravenous (i.v.) fluids and antimicrobial drugs were the primary strategies used when managing POI. Flunixin meglumine and i.v. lidocaine were the drugs most commonly used in the treatment of horses with POI. Supplementary management strategies targeted mainly the prevention of post operative adhesions, infection and inflammation.

CONCLUSIONS

There is a lack of consensus on the clinical definition of POI. Prospective and objective clinical assessment of the effectiveness of the different strategies contained within this and the European survey is necessary in order to identify a standardised approach to the management of equine POI.

Prevention of post operative complications following surgical treatment of equine colic: Current evidence

Changes in management of the surgical colic patient over the last 30 years have resulted in considerable improvement in post operative survival rates. However, post operative complications remain common and these impact negatively on horse welfare, probability of survival, return to previous use and the costs of treatment. Multiple studies have investigated risk factors for post operative complications following surgical management of colic and interventions that might be effective in reducing the likelihood of these occurring. The findings from these studies are frequently contradictory and the evidence for many interventions is lacking or inconclusive. This review discusses the current available evidence and identifies areas where further studies are necessary and factors that should be taken into consideration in study design.

Clinical features and management of equine post operative ileus: Survey of diplomates of the European Colleges of Equine Internal Medicine (ECEIM) and Veterinary Surgeons (ECVS)

REASONS FOR PERFORMING STUDY

There is a need for an improved understanding of equine post operative ileus (POI), in terms of both clinical definition and optimal management. Although the pharmacological strategies that are used to treat POI continue to evolve, little is known about the supplementary strategies used to prevent and manage this condition.

OBJECTIVES

To report the current strategies used to diagnose, prevent and manage POI following emergency abdominal surgeries.

STUDY DESIGN

Cross-sectional survey.

METHODS

An electronic survey invitation was sent by email to 306 European college diplomates (European Colleges of Equine Internal Medicine, ECEIM n = 120, and Veterinary Surgeons, ECVS n = 186).

RESULTS

The response rate was 33% (100 of 306). The median reported estimated incidence of POI was 10-20%. The presence of reflux on nasogastric intubation was the main criterion used to define POI. Lesions involving the small intestine were thought to be the leading risk factors for developing POI. Anti-inflammatory drugs, antimicrobial drugs and i.v. fluids were the primary preventative strategies when managing cases at high risk for POI. Flunixin meglumine and lidocaine were the drugs most commonly used to treat horses with POI. Supplementary preventative and treatment strategies for POI included control of endotoxaemia, fluid therapy, early ambulation and judicious timing of post operative feeding.

CONCLUSIONS

Appreciation of the potential risk factors associated with the development of POI appeared to have an impact on the choice of management strategies that are implemented. The majority of ECEIM and ECVS Diplomates in the survey used flunixin meglumine and lidocaine, often in combination, to treat horses with POI, which is likely to reflect the contributory role of inflammation in its pathophysiology. Various supplementary strategies were used to prevent and manage POI risk factors intraoperatively and post operatively.

Effects of experimental mechanical manipulations on local inflammation in the jejunum of horses

OBJECTIVE

To determine characteristics of the inflammatory reaction in the jejunum of horses in response to various mechanical manipulations.

ANIMALS

12 adult warm blood horses without gastrointestinal tract disorders.

PROCEDURES

The proximal aspect of the jejunum in each horse was divided into 5 segments, and the following manipulations were performed: manual emptying, placement of Doyen forceps, enterotomy alone, enterotomy with mucosal abrasion, and serosal abrasion. Jejunum samples were collected before (control), immediately after, and 30 minutes after the end of manipulations and histologically evaluated to determine distribution of neutrophils and eosinophils.

RESULTS

Macroscopically, all manipulations resulted in jejunal hemorrhage and edema. Compared with control samples, neutrophil numbers were significantly higher after manipulations in the serosa (after all manipulation types), circular muscle layer (after manual emptying), submucosa (after placement of Doyen forceps), and mucosa (after all manipulations except enterotomy alone). Eosinophil numbers were significantly higher in the submucosa after mechanical abrasion of the serosa and manual emptying versus control samples.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated mechanical manipulation of the jejunum resulted in local inflammatory reactions characterized predominantly by infiltration of neutrophils. This could contribute to the development of postoperative ileus or adhesions in horses without macroscopically detectable injury of the jejunum during surgery.

Occurrence of Incisional Complications After Closure of Equine Celiotomies With USP 7 Polydioxanone

OBJECTIVES

To report the occurrence of, and risk factors associated with, incisional complications of equine ventral median celiotomies closed with USP 7 polydioxanone (7PD).

STUDY DESIGN

Retrospective case series.

SAMPLE POPULATION

Horses (n = 73; 75 celiotomies).

METHODS

Medical records (2000-2010) were retrieved and reviewed for horses that had a ventral celiotomy closed with 7PD and survived ≥14 days. Follow-up (>1 year) was obtained from the medical record, owner, or referring veterinarian. Independent variables were selected based on risk factors identified in previous studies, perceived clinical relevance, and if there were adequate data recorded in the medical record. Statistical analysis, including multivariable logistic regression with a forward-building model process, was performed to evaluate variables associated with incisional complications.

RESULTS

One or more incisional complication(s) occurred in 19 celiotomies (25.3%) during hospitalization or after discharge including: drainage (25.3%), infection (12.0%), and partial dehiscence (5.3%). Two of 63 horses (3.2%) available for follow-up developed an incisional hernia. Variables associated with incisional complications after multivariate analysis included: number of days hospitalized, surgery time, postoperative colic, and postoperative fever.

CONCLUSION

Overall occurrence of incisional herniation after closure of ventral celiotomies with 7PD was low.

Serial viscoelastic and traditional coagulation testing in horses with gastrointestinal disease

OBJECTIVE

Objectives of this study were to compare the ability of serial thromboelastography, Sonoclot, and traditional coagulation panels to detect coagulopathies associated with disease category, systemic inflammatory response syndrome (SIRS), complications, and nonsurvival in horses with gastrointestinal disease.

DESIGN

Prospective clinical evaluation.

SETTING

University referral hospital.

ANIMALS

One hundred twenty-one horses admitted as emergencies for gastrointestinal disease and 28 healthy adult horses.

INTERVENTION

Blood samples were collected ≤4 times from emergency horses (admission and if surviving and hospitalized on days 2-4) and once from healthy horses. Thromboelastography (with and without tissue factor activation), Sonoclot, and a traditional coagulation panel were performed on each sample.

MEASUREMENTS AND MAIN RESULTS

Emergency horses were grouped based on disease category (ie, nonstrangulating medical, nonstrangulating surgical, strangulating, and inflammatory), survival to discharge, SIRS at admission, requirement for exploratory celiotomy, ileus, diarrhea, fever, thrombophlebitis, and laminitis. Changes over time were evaluated individually and compared between disease groups. Horses with gastrointestinal disease had dynamic changes in coagulation and fibrinolysis during the first 4 days of hospitalization that were correlated with disease category, SIRS, complications, and fatality. The multivariate logistic regression model for nonsurvival included activated partial thromboplastin time on day 2 and LY30 on day 3 (overall model significance P < 0.0001). The odds of nonsurvival were 23.75 times higher if activated partial thromboplastin time was >85.6 s on day 2 and 9.38 times higher if LY30 was >1% on day 3.

CONCLUSIONS

Horses with gastrointestinal disease have activation of coagulation and fibrinolysis. Magnitude of change in these parameters is small and predictive value moderate, making application of these tests to direct therapy in clinical patients difficult. Effect of specific treatments (eg, surgery) on these tests and coagulation has not been determined. Further studies are required to determine if these tests could be used to help monitor response to treatment in individual animals or specific disease states.

In vivo and in vitro effects of neostigmine on gastrointestinal tract motility of horses

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.

Risk factors for colic in equids hospitalized for ocular disease

OBJECTIVE

To evaluate the incidence of colic and risk factors for colic in equids hospitalized for ocular disease.

DESIGN

Retrospective observational study. Animals-337 equids (317 horses, 19 ponies, and 1 donkey) hospitalized for ocular disease.

PROCEDURES

Medical records of equids hospitalized for > 24 hours for treatment of ocular disease between January 1997 and December 2008 were reviewed. Information from only the first hospitalization was used for equids that were hospitalized for ocular disease on more than 1 occasion. Information gathered included the signalment, the type of ocular lesion and the treatment administered, and any colic signs recorded during hospitalization as well as the severity, presumptive diagnosis, and treatment of the colic. Statistical analysis was used to identify any risk factors for colic in equids hospitalized for ocular disease.

RESULTS

72 of 337 (21.4%) equids hospitalized for ocular disease had signs of colic during hospitalization. Most equids (59.7% [43/72]) had mild signs of colic, and most (87.5% [63/72]) were treated medically. Ten of 72 (13.9%) equids with colic had a cecal impaction. Risk factors for colic in equids hospitalized for ocular disease were age (0 to 1 year and ≥ 21 years) and an increased duration of hospitalization (≥ 8 days).

CONCLUSIONS AND CLINICAL RELEVANCE

There was a high incidence of colic in equids hospitalized with ocular disease in this study. Findings from this study may help identify equids at risk for development of colic and thereby help direct implementation of prophylactic measures.

Thrombelastography in horses with acute gastrointestinal disease

BACKGROUND

Coagulopathies in horses with gastrointestinal disease are frequently identified and associated with morbidity and fatality.

OBJECTIVE

Determine if thrombelastography (TEG) identifies abnormalities associated with lesion type, presence of systemic inflammatory response syndrome (SIRS), morbidity, and fatality more consistently than traditional coagulation testing.

ANIMALS

One-hundred and one horses examined for gastrointestinal disease and 20 healthy horses.

METHODS

TEG, tissue factor (TF)-TEG, and traditional coagulation panels parameters and percentages of horses with coagulopathies were compared for lesion type, presence of SIRS, complications, and survival.

RESULTS

Changes in individual parameters and increased incidence of coagulopathies were associated with fatality (R, P= .007; k-value [K], P= .004; clot lysis [CL]30, P= .037; CL60, P= .050; angle [Ang], P= .0003; maximum amplitude [MA], P= .006; lysis [Ly]30, P= .042; Ly60, P= .027; CI, P= .0004; ≥ 2 TEG coagulopathies, P= .013; ≥ 3 TEG coagulopathies, P= .038; TF-R, P= .037; TF-K, P= .004; TF-CL30, P < .0001; TF-CL60, P < .0001; TF-Ang, P= .005; TF-Ly30, P= .0002; TF-Ly60, P < .0001; TF-CI, P= .043; ≥ 1 TF-TEG coagulopathies, P= .003; ≥ 2 TF-TEG coagulopathies, P= .0004; prothrombin tme [PT], P < .0001; activated partial throboplastin time [aPTT], P= .021), inflammatory lesions (MA, P= .013; TF-CL30, P= .033; TF-CL60, P= .010; TF-Ly60, P= .011; ≥ 1 TF-TEG coagulopathy, P= .036; ≥ 2 TF-TEG coagulopathy, P= .0007; PT, P= .0005; fibrinogen, P= .019), SIRS (MA, P= .004; TF-CL30, P= .019; TF-CL60, P= .013; TF-Ly30, P= .020; TF-Ly60, P= .010; PT, P < .0001; aPTT, P= .032; disseminated intravascular coagulation, P= .005), and complications (ileus: aPTT, P= .020; diarrhea: TF-CL30, P= .040; TF-Ly30, P= .041; thrombophlebitis: ≥ 1 TF-TEG coagulopathy, P= .018; laminitis: MA, P= .004; CL60, P= .045; CI, P= .036; TF-MA, P= .019; TF-TEG CI, P= .019). Abnormalities in TEG and TF-TEG parameters were indicative of hypocoagulation and hypofibrinolysis.

CONCLUSIONS AND CLINICAL IMPORTANCE

TEG identifies changes in coagulation and fibrinolysis associated with lesion type, SIRS, morbidity, and fatality in horses with gastrointestinal disease.