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)

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.

Standing surgery among equine board certified surgeons: Survey regarding current use and trends

BACKGROUND

Publications about equine standing surgery are flourishing, however, information regarding its use and prevalence among surgeons is still limited.

OBJECTIVES

To determine the current use and recent trends for equine standing surgery among board certified surgeons and to identify the main reasons and limitations for performing a procedure standing.

STUDY DESIGN

Cross-sectional survey.

METHODS

A 139-item questionnaire was sent by email to 733 large animal surgery Diplomates (ACVS and ECVS) from November 2020 to February 2021. The survey collected demographic information and general data regarding standing surgery before being divided into seven identical sections for each body system, involving 36 standing procedures.

RESULTS

The survey response rate was 29.7% (218/733). Most respondents (58.9%, 126/214) had performed standing surgery for <10 years regardless of length of time they were board certified (48.2% board certified <10 years and 51.8% >10 years). Most respondents (range: 50.0%-92.9%, mean 69.5%) changed from performing 14/36 surgeries under general anaesthesia (GA) to standing within the previous 10 years and had always performed 8/36 surgeries standing (51.6%-73.9%, mean 61.4%) regardless of board certification time. Surgeons board certified <10 years ago performed more often 3/36 listed procedures standing than those board certified >10 years ago (p < 0.05). Avoiding GA (179/218) and/or reducing procedure cost (111/218) were the two main reasons to perform standing surgeries whereas the horse's behaviour (183/218) and/or the patient size/age (94/218) were the two main limiting factors.

MAIN LIMITATIONS

Low response rate. Results biased towards the opinion of a subgroup of surgeons, those performing standing surgery. Some standing procedures were not included in the survey.

CONCLUSIONS

The use of standing surgery is well established among board certified surgeons and progressively increasing, especially in the last 10 years and among recent Diplomates. With increased training and awareness, more Diplomates may be encouraged towards performing standing surgeries.

Basic Postoperative Care of the Equine Colic Patient

The 3 time periods around colic surgery (preoperative, operative, and postoperative) are all critical to successful outcomes. Although much focus is often paid to the first 2 time periods, the importance of sound clinical judgment and rational decision-making in the postoperative period cannot be overstated. This article will outline the basic principles of monitoring, fluid therapy, antimicrobial therapy, analgesia, nutrition, and other therapeutics routinely used in patients following colic surgery. Discussions of the economics of colic surgery and expectations for normal return to function will also be included.

Variations in the application of equine prosthetic laryngoplasty: A survey of 128 equine surgeons

OBJECTIVE

To document variations in the application of equine prosthetic laryngoplasty among equine surgeons.

STUDY DESIGN

Cross-sectional survey.

SAMPLE POPULATION

Six hundred and seventy-eight equine surgeons performing prosthetic laryngoplasty.

METHODS

An online questionnaire was sent to equine surgeons, including diplomates of the American College of Veterinary Surgeons and European College of Veterinary Surgeons. Questions focused on participant profile, surgical technique, antimicrobial therapy, and concurrent procedures. Descriptive statistical analysis was performed on the survey output.

RESULTS

Complete responses were received from 128/678 individuals, mostly from experienced surgeons. Most participants used 2 prostheses (106/128, 82.8%) and a single loop was the most common method used to anchor the prosthesis in the cricoid (95/128, 74.2%) and arytenoid (125/128, 97.7%) cartilages. Use of general anesthesia was common, although 46/128 (35.9%) participants now performed most laryngoplasty surgery with standing sedation. The material used as a prosthesis varied among surgeons, although participants typically aimed to achieve grade 2 intraoperative arytenoid abduction. Participants most commonly administered perioperative systemic antimicrobial therapy for 1-3 days (57/128, 44.5%) and 48/128 (37.5%) used local antimicrobial therapy.

CONCLUSION

Most surgeons performed laryngoplasty with 2 prostheses, a single loop construct at the muscular process of the arytenoid cartilage and systemic antimicrobial therapy. There was variation in the preferred method of surgical restraint, prosthesis material selection, and use of local antimicrobial therapy.

CLINICAL SIGNIFICANCE

Long-established techniques remain popular in clinical practice despite evidence that variations offer advantages, particularly in relation to biomechanics. Other factors are also likely to influence technique selection in a clinical context.

Postoperative Ileus: Comparative Pathophysiology and Future Therapies

Postoperative ileus (POI), a decrease in gastrointestinal motility after surgery, is an important problem facing human and veterinary patients. 37.5% of horses that develop POI following small intestinal (SI) resection will not survive to discharge. The two major components of POI pathophysiology are a neurogenic phase which is then propagated by an inflammatory phase. Perioperative care has been implicated, namely the use of opioid therapy, inappropriate fluid therapy and electrolyte imbalances. Current therapy for POI variably includes an early return to feeding to induce physiological motility, reducing the inflammatory response with agents such as non-steroidal anti-inflammatory drugs (NSAIDs), and use of prokinetic therapy such as lidocaine. However, optimal management of POI remains controversial. Further understanding of the roles of the gastrointestinal microbiota, intestinal barrier function, the post-surgical inflammatory response, as well as enteric glial cells, a component of the enteric nervous system, in modulating postoperative gastrointestinal motility and the pathogenesis of POI may provide future targets for prevention and/or therapy of POI.

Effect of Feed Intake on Water Consumption in Horses: Relevance to Maintenance Fluid Therapy

Maintenance fluid therapy is challenging in horses that cannot drink or are denied feed and water because of concerns about gastrointestinal tract function and patency. Intravenous fluid delivery to meet water needs based on current recommendations for maintenance requirements were obtained in fed horses and therefore might not apply to horses that are not being fed. This is a critical flaw because of the interdependence between intestinal tract water and extracellular water to support digestion while preserving water balance, a concept explained by the enterosystemic cycle. Because horses drink less when they are not eating and hence have lower water needs than fed horses, maintenance water requirements need to be adjusted accordingly. This article reviews this topic and identifies benefits of adjusting maintenance fluid therapy to meet lower demands from gastrointestinal function, such as reduced volumes, lower cost, avoidance of overhydration.

Equine nutrition in the post-operative colic: Survey of Diplomates of the American Colleges of Veterinary Internal Medicine and Veterinary Surgeons, and European Colleges of Equine Internal Medicine and Veterinary Surgeons

Background

Evidence is lacking concerning re‐introduction of feed and water following colic surgery.

Objectives

To describe current approaches of European and American specialists to re‐introduction of feed and water in adult horses following surgical treatment of common intestinal lesions, assuming an uncomplicated recovery.

Study design

Cross‐sectional survey.

Methods

Electronic invitations, with a link to the online survey, were sent to 1,430 large animal specialists, including Diplomates of the ECVS, ACVS, ECEIM and ACVIM colleges.

Results

The response rate was 12.6% including partial respondent data. Responses for each multiple‐choice question were between 123 and 178. Results are expressed as the percentage of the total number of responses and as a range where specific lesions are grouped together. Respondents reported that horses with large intestinal displacements were offered free choice water (63%‐65%) within 3 hours (55%‐63%), whereas horses with a small intestinal strangulating lesion were offered < 2 L water (64%‐74%) 12‐24 hours (28%‐34%) post‐operatively. Horses with a large colon displacement were offered feed within 3 hours of surgery (16%) with the majority offered feed 6‐12 hours (35%‐36%) post‐operatively. Horses with small intestinal strangulating lesions and small colon lesions were offered feed 24‐48 hours (34%‐42%) after surgery. Following small intestinal, small colon or caecal lesions, horses were re‐introduced feed in handfuls (79%‐93%) and initially with grass (41%‐54%). Horses with large colon displacements were mostly fed handfuls (49%‐50%) of forage initially, but a number of respondents would offer larger quantities such as a small bucket (35%‐37%) and predominantly of hay (50%‐51%).

Main limitations

Low response rate. This study did not take into account common post‐operative complications that may alter the clinical approach.

Conclusions

This post‐operative colic nutrition survey is the first to describe current clinical practice. Further research is required to investigate nutritional strategies in post‐operative colic cases.

Ultrasonographic evaluation of the effects of the administration of neostigmine and metoclopramide on duodenal, cecal, and colonic contractility in Arabian horses: A comparative study

Background and Aim

As means for enhancing gastrointestinal (GI) motility, prokinetics have previously been evaluated in different breeds of horses with varying success. No previous studies were conducted to evaluate the effect of prokinetics on the intestinal tract of Arabian horses breed. Using B-mode ultrasound in the quantification of intestinal contractility, this study aimed to compare the impact of neostigmine and metoclopramide on the intestinal motility of healthy Arabian horses.

Materials and Methods

Twenty-one clinically healthy Arabian horses were equally distributed into three groups. The control group was administered with 5 mL normal saline intramuscularly (IM). The second group was administered with neostigmine (0.044 mg/kg body weight [BW], IM), and the third group was administered with metoclopramide (0.25 mg/kg BW, IM). Duodenal, cecal, and colonic contractions were counted through ultrasonography for 3 min (pre-administration and 15, 30, 60, 120, and 180 min post-administration).

Results

In the neostigmine group, a significant (p<0.05) increase in duodenal, cecal, and colonic contractions was observed 15 min post-administration compared with that in the control group (15±1.0, 11.33±1.53, and 12.33±2.31 vs. 11.0±2.0, 6.33±0.58, and 5.33±0.58 contractions per 3 min, respectively), continuing to 60 min post-administration for the duodenum and cecum and 120 min for colon and then returning to the normal; however, the metoclopramide group showed a significant (p<0.05) increase only in cecal and colonic contractions 60 min post-administration compared with the control group (11.0±1.0 and 12.33±0.58 vs. 6±1.0 and 5.67±0.58 contractions per 3 min, respectively), continuing until the end of the experiment. Excessive sweating, excitation, and straining were recorded following the administration of neostigmine, whereas no side effects were observed in the metoclopramide group.

Conclusion

Neostigmine improves duodenal, cecal, and colonic contractions in healthy adult Arabian horses, whereas metoclopramide only improves cecal and colonic contractions. Metoclopramide appears to be safer and longer acting than neostigmine in the Arabian horse breed. Ultrasonography is a valuable noninvasive tool for the quantification of intestinal contractility. Future studies should consider the use of various dosages of metoclopramide and administration routes and investigate its impact on horses with GI transit disorders and inclusion in colic post-operative care.

A wireless endoscopy capsule suitable for imaging of the equine stomach and small intestine

Background

Capsule endoscopy offers a new method for visualization of the gastrointestinal mucosa in horses where other imaging technologies have diagnostic limitations.

Objectives

To (1) test the feasibility of using this novel endoscopy capsule to visualize intestinal mucosa in horses, including an objective assessment of image quality, (2) assess how changes in preadministration preparation affect the transit time and the amount of gastrointestinal mucosa visualized, and (3) describe intestinal mucosa lesions in healthy horses.

Animals

Five healthy adult horses.

Methods

Three protocols were used in a crossover study design. Protocols varied in time fasted, amount of oral fluid administered, and exercise. Manure was radiographically inspected for capsule recovery. Percentage of visible gastrointestinal mucosa was objectively assessed.

Results

Detailed images of the gastrointestinal mucosa were recorded with all 3 protocols, including images of the pylorus, major duodenal papilla, individual villi, and ileocecal junction. Visualization of large intestinal mucosa was poor. Interobserver agreement on image quality was excellent. Capsule administration after feed withholding for 24 hours provided the greatest percentage of visible mucosa in the stomach and small intestine. Total transit time to capsule excretion was 6.5 (3‐8.75) days. Of 15 capsules administered, 3 were not recovered. Lesions visualized included mucosal erosion, ulceration and hemorrhage, areas of thickened mucosa, and evidence of parasitism.

Conclusions

This novel endoscopic capsule appears safe, practical, and noninvasive in horses; however, variability in capsule excretion time must be taken into account for clinical application.

Preconditioning with lidocaine and xylazine in experimental equine jejunal ischaemia

BACKGROUND

Pharmacological preconditioning of dexmedetomidine on small intestinal ischaemia/reperfusion injury has been reported in different animal models including horses.

OBJECTIVES

The objective was to assess if xylazine and lidocaine have a preconditioning effect in an experimental model of equine jejunal ischaemia.

STUDY DESIGN

Terminal in vivo experiment.

METHODS

Ten horses under general anaesthesia were either preconditioned with xylazine (group X; n = 5) or lidocaine (group L; n = 5). A historical untreated control group (group C; n = 5) was used for comparison. An established experimental model of equine jejunal ischaemia was applied, and intestinal samples were taken pre-ischaemia, after ischaemia and following reperfusion. Histomorphological examination was performed based on a modified Chiu score. Immunohistochemical staining for cleaved caspase-3, TUNEL and calprotectin was performed, and positive cell counts were expressed in cells/mm² .

RESULTS

There was no progression of histomorphological mucosal injury from ischaemia to reperfusion, and there were no differences in histomorphology between the groups. After ischaemia, group X had significantly less caspase-positive cells compared to the control group with a median difference of 227% (P = .01). After reperfusion, group X exhibited significantly lower calprotectin-positive cell counts compared to the control group, with a median difference of 6.8 cells/mm² in the mucosa and 44 cells in the serosa (P = .02 and .05 respectively). All groups showed an increase in caspase- and calprotectin-positive cells during reperfusion (P < .05). TUNEL-positive cells increased during ischaemia, followed by a decrease after reperfusion (P < .05).

MAIN LIMITATIONS

The small sample size and the use of a historical control group. Preconditioning effects of the tested drugs may be masked by the protective effects of isoflurane in the anaesthetic protocol.

CONCLUSIONS

Preconditioning with lidocaine did not have any effect on the tested variables. The lower cell counts of caspase- and calprotectin-positive cells in group X may indicate a beneficial effect of xylazine on ischaemia/reperfusion injury. Due to the absence of a concurrent reduction of histomorphological injury, the clinical significance remains uncertain.

Is There Still a Place for Lidocaine in the (Postoperative) Management of Colics?

Intravenous lidocaine is widely used to prevent or treat postoperative ileus in horses. Clinical studies that support this approach are flawed and contradicted by others. Also, physical obstruction could be more important in causing postoperative reflux than postoperative ileus in the horse. The antiinflammatory properties of lidocaine and the role of inflammation from intestinal handling in the genesis of postoperative reflux are questionable. Because of cost and questionable efficacy of lidocaine, a well-designed clinical trial is required to support its continued use. However, lidocaine could be given to provide or enhance analgesia in selected cases with postoperative 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.

Has intravenous lidocaine improved the outcome in horses following surgical management of small intestinal lesions in a UK hospital population?

Background

Perioperative lidocaine treatment is commonly used in horses that undergo surgical treatment of colic, to prevent or treat postoperative ileus and reduce the effects of intestinal ischaemia-reperfusion injury. However, its clinical efficacy has not been evaluated in a large population of horses undergoing small intestinal surgery. The aim of the current study was to evaluate whether systemic lidocaine administration reduced the prevalence, volume and duration of postoperative reflux and improved rates of survival following surgical treatment of small intestinal lesions. Data were collected as a part of two prospective studies investigating postoperative survival of surgical colic patients admitted to a UK equine referral hospital during the periods 2004–2006 and 2012–2014. Kaplan-Meier plots of cumulative probability of survival and the log-rank test were used to compare survival between horses that did or did not receive lidocaine. The Wilcoxon rank-sum test was used to compare the total reflux volume and duration of reflux between the groups. A multivariable Cox proportional hazards model was used to identify pre- and intraoperative risk factors for non-survival.

Results

Data from 318 horses were included in the final analysis. The overall prevalence of postoperative reflux was 24.5 %. This was significantly higher (34.8 %) in horses admitted in 2012–2014 compared to the 2004–2006 cohort (16.7). Perioperative lidocaine treatment had no effect on total reflux volume, duration of reflux or rates of postoperative survival nor was it a risk factor associated with altered postoperative survival. Variables identified to be associated with increased risk of postoperative mortality included packed cell volume on admission (hazard ratio [HR] 1.03 95 %, 95 % confidence interval [CI] 1.004–1.06, p = 0.024), heart rate on admission (HR 1.014, 95 % CI 1.004–1.024, p =0.008) and duration of surgery (HR 1.007, 95 % CI 1.002–1.01, p = 0.008).

Conclusions

Lidocaine therapy had no effect on the prevalence of postoperative reflux, total reflux volume and duration of reflux nor did it have any effect on postoperative survival in horses undergoing surgical management of small intestinal disease for treatment of colic. There is a need for a well-designed multicentre, prospective randomised controlled trial to fully investigate the efficacy of lidocaine across different hospital populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-016-0784-7) contains supplementary material, which is available to authorized users.

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.

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.