Nonstrangulating Lesions Research Articles

Current Antimicrobial Use in Horses Undergoing Exploratory Celiotomy: A Survey of Board-Certified Equine Specialists.

In the past decade, there has been a considerable increase in the recognition of antimicrobial resistance in equine practice. The objective of this study was to survey the current clinical use of antimicrobials for a commonly performed surgical procedure (exploratory celiotomy) with the goal of understanding how recent literature and changes in microbial resistance patterns may have impacted antimicrobial selection practices. An electronic survey was distributed to veterinary professionals within the American College of Veterinary Internal Medicine (ACVIM) and the American College of Veterinary Surgery (ACVS). A total of 113 completed surveys were returned. Practitioners reported antimicrobials were most frequently given 30-60 min preoperatively (63.1%). Two antimicrobial classes were typically administered (95.5%), with gentamicin (98.2%) and potassium penicillin (74.3%) being the most common. Antimicrobials were typically not re-dosed intraoperatively (78.6%). Factors that affected overall treatment length postoperatively included resection (81.4%), bloodwork (75.2%), enterotomy (74.3%), fever (85.0%), incisional complications (76.1%), and thrombophlebitis (67.3%). The most common duration of antimicrobial use was 1-3 d for non-strangulating lesions (54.4% of cases) and inflammatory conditions such as enteritis or peritonitis (50.4%), and 3-5 d for strangulating lesions (63.7%). Peri-incisional and intra-abdominal antimicrobials were used by 24.8% and 11.5% of respondents, respectively. In summary, antimicrobial usage patterns were highly variable among practitioners and, at times, not concordant with current literature.

Strangulating lesions of the small intestine associated with the greater omentum in horses: 32 cases

SummaryBackgroundStrangulating lesions of the small intestine involving the greater omentum (SSIGOs) have only rarely been reported. Furthermore, information pertaining to clinical descriptions, surgical findings and outcome is lacking.ObjectivesThe objective of this study was to describe the prevalence, clinical presentation, surgical findings, postoperative outcome and risk factors associated with SSIGOs.Study designThis is a retrospective case series of 32 horses with a diagnosis of SSIGOs.MethodsData from hospital records of horses identified with SSIGOs between 2005 and 2020 including signalment, clinical findings at presentation, initial laboratory results, surgical findings, surgical procedures performed and postoperative survival were analysed. The prevalence of SSIGOs was determined. SSIGO was compared with small intestinal strangulating and nonstrangulating lesions and other types of colic to identify potential risk factors among signalment data and to determine outcome, using multiple logistic regression models.ResultsSSIGOs were present in 2.3% (32/1413) of all horses undergoing exploratory laparotomy for colic, 4.7% of all horses with primary small intestinal lesions (32/683) and 5.6% of strangulating small intestinal lesions (32/570). Surgical findings included primary strangulation by the greater omentum with or without involvement of a lipoma‐like mass originating from the greater omentum (15/32 [47%]), adhesions involving the greater omentum leading to strangulation of the small intestine (14/32 [44%]) and small intestine incarceration through an omental rent (3/32 [9%]). The short‐term survival rate defined as survival until discharge was 53% (17/32) considering all SSIGO cases, and 85% (17/20) for SSIGO cases recovered from anaesthesia. Risk factors identified were increasing age and year of surgery.Main limitationsThe limitations of this study are retrospective study design and the limited number of SSIGO cases reflecting the rarity of this condition.ConclusionsNumerous anatomical configurations of SSIGO exist, but clinical presentation is similar to other strangulating small intestinal lesions. Although uncommon, SSIGOs should be considered a potential cause of small intestine strangulation.

Diagnostic value of plasma and peritoneal fluid procalcitonin concentrations in horses with strangulating intestinal lesions.

To assess the diagnostic value of plasma and peritoneal fluid procalcitonin concentrations for identification of horses with strangulating intestinal lesions. 65 horses with signs of colic of intestinal origin and 10 healthy (control) horses. For each horse, plasma and peritoneal fluid samples were obtained for a CBC and determination of total protein, procalcitonin, and lactate concentrations. Signalment and clinicopathologic findings were compared among control horses and horses with strangulating and nonstrangulating intestinal lesions. Mean ± SD plasma (274.9 ± 150.8 pg/mL) and peritoneal fluid (277 ± 50.6 pg/mL) procalcitonin concentrations for horses with colic were significantly greater than the mean ± SD plasma (175.5 ± 46.0 pg/mL) and peritoneal fluid (218.8 ± 48.7 pg/mL) procalcitonin concentrations for control horses. Mean procalcitonin concentration in peritoneal fluid, but not plasma, differed significantly between horses with strangulating lesions and those with nonstrangulating lesions. A peritoneal fluid procalcitonin concentration ≥ 281.7 pg/mL had a sensitivity of 81%, specificity of 69%, positive predictive value of 56.7%, and negative predictive value of 87.9% for detection of strangulating lesions. Results suggested that peritoneal fluid procalcitonin concentration, when evaluated in conjunction with other clinicopathologic results, might be a sensitive indicator of intestinal ischemia and facilitate early identification of horses that require surgery to address a strangulating lesion.

Predictive value of plasma and peritoneal creatine kinase in horses with strangulating intestinal lesions.

To determine the ability of plasma and peritoneal creatine kinase (CK) to predict the presence of a strangulating lesion in horses presented for colic. Prospective clinical study. Ten healthy control horses and 61 clinical colic cases. Creatine kinase activity was measured in peritoneal fluid and plasma of 10 healthy horses and 61 horses presenting for colic (40 horses with nonstrangulating lesions and 21 horses with strangulating lesions). Information on other blood and peritoneal fluid variables, signalment, results from the physical examination, outcome, requirement for surgery, and lesion location and type were retrieved from the medical records of horses presenting for colic. A peritoneal CK cutoff level of 16 IU/L yielded a sensitivity of 95.2% and a specificity of 84.6% (positive predictive value [PPV] = 76.9% and negative predictive value [NPV] = 97%, respectively) for predicting a strangulating lesion. A peritoneal lactate cutoff level of 3.75 mmol/L yielded a sensitivity of 81% and a specificity of 92% (PPV = 85% and NPV = 90%, respectively) for predicting a strangulating lesion. Peritoneal CK concentration was a sensitive indicator of the presence of a strangulating lesion in horses presenting with colic, whereas peritoneal lactate concentration was a more specific indicator. Measuring CK in peritoneal fluid may be a useful adjunct to clinical case presentation to accelerate the diagnosis and definitive treatment of horses presenting with strangulating intestinal lesions, thereby improving their outcome.

Evaluation of neutrophil apoptosis in horses with acute abdominal disease

To quantify peripheral blood neutrophil apoptosis in equine patients with acute abdominal disease (ie, colic) caused by strangulating or nonstrangulating intestinal lesions and compare these values with values for horses undergoing elective arthroscopic surgery. 20 client-owned adult horses. Peripheral blood was collected from horses immediately prior to and 24 hours after surgery for treatment of colic (n = 10) or elective arthroscopic surgery (10), and neutrophils were counted. Following isolation by means of a bilayer colloidal silica particle gradient and culture for 24 hours, the proportion of neutrophils in apoptosis was detected by flow cytometric evaluation of cells stained with annexin V and 7-aminoactinomycin D. Values were compared between the colic and arthroscopy groups; among horses with colic, values were further compared between horses with and without strangulating intestinal lesions. Percentage recovery of neutrophils was significantly smaller in preoperative samples (median, 32.5%) and in all samples combined (35.5%) for the colic group, compared with the arthroscopy group (median, 66.5% and 58.0%, respectively). No significant differences in the percentages of apoptotic neutrophils were detected between these groups. Among horses with colic, those with strangulating intestinal lesions had a significantly lower proportion of circulating apoptotic neutrophils in postoperative samples (median, 18.0%) than did those with nonstrangulating lesions (66.3%). The smaller proportion of apoptotic neutrophils in horses with intestinal strangulation suggested that the inflammatory response could be greater or prolonged, compared with that of horses with nonstrangulating intestinal lesions. Further investigations are needed to better understand the relationship between neutrophil apoptosis and inflammation during intestinal injury.

Blood lactate concentrations in ponies and miniature horses with gastrointestinal disease

Clinical impression suggested that pony and miniature breeds (collectively referred to as ponies) presenting to a referral hospital for investigation of gastrointestinal disease had higher blood lactate concentrations on admission than large breed horses. The study tested the hypothesis that ponies with gastrointestinal disease had higher blood lactate concentrations on admission than large breed horses with similar disease severity. Retrospective case-control study. Medical records from September 2006 to July 2011 were reviewed for ponies with a primary presenting complaint of gastrointestinal disease. Two larger breed horses with gastrointestinal disease were selected as controls for each case. Data collected included case details, historical and clinicopathological findings, diagnosis and outcome. Information was collected on 50 ponies and 100 horses. Ponies had higher mean ± s.d. respiratory rates (27 ± 13 vs. 21 ± 13 beats/min; P = 0.01) and rectal temperatures (37.9 ± 0.6 vs. 37.4 ± 0.6°C; P = 0.006) and a longer median duration of clinical signs prior to presentation (10 h [1-72 h] vs. 6 h [1-120]; P<0.001). Median blood lactate concentrations on admission were higher in ponies than in horses (2.8 mmol/l [0.7-18.0] vs. 1.6 mmol/l [0.4-8.1]; P = 0.001). All other parameters relating to colic severity were not significantly different between groups, although more horses underwent exploratory laparotomy (19/50 ponies and 55/100 horses; P = 0.05). Median blood lactate concentrations in ponies with large intestinal disease, nonstrangulating lesions, undergoing medical treatment and surviving ponies were significantly higher than in horses in the same category. In contrast to horses, no differences in blood lactate concentrations exist between ponies with medical vs. surgical treatment, strangulating and nonstrangulating lesions and surviving and nonsurviving ponies. Ponies might present with higher blood lactate concentrations than horses and might falsely be suspected of having a surgical lesion or a poorer prognosis if veterinarians are not aware of breed differences.

Clinical comparison between a continuous Lembert pattern wrapped in a carboxymethylcellulose and hyaluronate membrane with an interrupted Lembert pattern for one‐layer jejunojejunostomy in horses

Although experimental studies have demonstrated differences in performance between methods for handsewn jejunojejunostomy in horses, information on clinical results after different methods of anastomosis are rare. A continuous Lembert pattern wrapped in a carboxymethylcellulose and hyaluronate membrane would perform better than an interrupted Lembert pattern for jejunojejunostomy in horses. Data was reviewed on 32 horses that underwent jejunojejunostomy from 1993-2002. Kaplan-Meier analyses and rates for post operative colic and death were used to compare outcomes after an interrupted Lembert pattern (15 horses with strangulating lesions and 5 horses with nonstrangulating lesions) and a continuous Lembert pattern with membrane (12 horses with strangulating diseases). None of the 32 horses had post operative ileus or post operative endotoxaemia. One horse with a continuous pattern required a repeat celiotomy for anastomotic impaction. Short-term survivals for the interrupted Lembert were 100% (nonstrangulating lesions) and 93% (strangulating lesions) and for the continuous pattern 92% (all strangulating). Long-term rates for mortality and colic episodes were less for the continuous Lembert pattern with membrane compared with the interrupted Lembert for strangulating lesions (P<0.05) and were less for strangulating lesions than for nonstrangulating lesions (P<0.05). For strangulating lesions, Kaplan-Meier analyses yielded a survival probability of 70% for up to 9 years after the interrupted Lembert pattern and 80% for up to 5 years for the continuous Lembert pattern. Both Lembert patterns performed well in clinical use, although the continuous pattern with the carboxymethylcellulose and hyaluronate membrane had superior long-term outcomes with less colic and mortality from colic.

Initial investigation of mortality rates and prognostic indicators in horses with colic in Israel: A retrospective study

Initial assessment of the mortality rates and prognostic indicators in horses with colic presented to a referral hospital in Israel. To determine mortality rates and to identify potential prognostic indicators in horses undergoing treatment for colic. The medical records of 208 colic cases were reviewed and mortality rates calculated including 95% confidence intervals. Mortality rates in surgical cases were calculated separately for strangulating and nonstrangulating lesions as well as for lesions of the large and small intestines. Potential prognostic indicators were identified and evaluated by Student's t test or chi2 test, where appropriate. Those found to be significant (P < 0.05) were evaluated in 2 logistic regression models; one including all horses with colic and one for surgical cases only. The overall mortality rate was 51/208 (25%); 5/72 (7%) in medically treated cases, 46/136 (34%) in surgical cases, 30/50 (60%) in strangulating lesions and 15/85 (18%) in nonstrangulating lesions, 17/27 (63%) in cases involving small intestinal lesions and 28/108 (26%) in cases with large intestinal lesions. Clinical parameters found to be significantly associated with death by univariate analysis were medical/surgical treatment, location of lesion, severity of lesion, mucous membrane colour (MM), capillary refill time (CRT) and heart rate. Using a multivariate logistic regression model, including all cases, medical/surgical treatment, CRT and MM were found to be prognostic indicators and when using the surgical cases alone, only CRT and lesion severity remained related to mortality. Mortality rates were similar or better than those previously reported in most cases, however, studies from the USA and the UK published better success rates for small intestinal surgeries. Cultural attitudes toward euthanasia may be associated with mortality rates. These results assist clinicians in providing an immediate prognosis based on clinical findings at presentation and contribute to an international database that may aid future research in improving treatment of colic.

Electrolyte disorders in horses with colic. Part 1: potassium and magnesium

Electrolyte disorders are common in horses with acute abdominal disease, and are a significant cause of morbidity. They are especially prevalent in horses treated surgically for colic, and may be present before, during and after surgery. In one study, 54% of horses admitted for surgical colic had preoperative serum ionised magnesium concentrations below the reference range and 86% subnormal serum ionised calcium concentrations (Garcia-Lopez et al. 2001). Electrolyte abnormalities are particularly prevalent in horses with strangulating obstructions of the intestine. These horses have lower preoperative serum concentrations of ionised magnesium and calcium than horses with nonstrangulating lesions (Dart et al. 1992; Garcia-Lopez et al. 2001). Horses with decreased preoperative ionised magnesium were also more likely to be subjected to euthanasia during surgery. The role of electrolyte derangements in contributing to adverse clinical events in horses with colic is still being investigated. The association between cardiac electrical disorders and blood calcium, magnesium and potassium concentrations is well established in the horse (Harrington 1974; Glazier et al. 1979, 1982; Reef 1999) (Fig 1). Derangements in blood electrolyte concentration might also be associated with a longer hospital stay. Martin et al. (1994) reported that dogs with low serum magnesium concentrations were hospitalised for twice as long as those with a normal serum magnesium concentration. Conversely, Garcia-Lopez et al. (2001) did not find any correlation between serum ionised magnesium or calcium concentrations and length of hospitalisation, incidence of complications or survival in horses treated surgically for colic. The association between serum concentrations of potassium, calcium and magnesium with post operative ileus is still unknown in the horse. Dart et al. (1992) speculated that decreased serum calcium concentrations might contribute to ileus. Garcia-Lopez et al. (2001) found lower serum concentrations of ionised magnesium and calcium in horses that developed post operative ileus, than in those that did not. These decreased electrolyte concentrations may be due to decreased intake and increased loss of electrolytes in gastric reflux. It is now possible to measure electrolytes using ‘patientside’ portable analysers. The introduction of these cartridgebased systems has enabled results to be obtained quickly and easily when laboratory techniques are unavailable (Grosenbaugh et al. 1998). Different sensors are available to measure different combinations of electrolytes, blood biochemistry, PCV and blood gas tensions. The price of these hand-held devices is rapidly decreasing and they are now affordable for many private practices. The normal range for any electrolyte may vary to some degree between analysers. Therefore, horse specific normal ranges should be obtained from the manufacturers, if possible. In Part 1, we discuss the importance of potassium and magnesium and Part 2 covers calcium, sodium, chloride and phosphorus.

Prevalence and prognostic importance of hypomagnesemia and hypocalcemia in horses that have colic surgery.

To determine the prevalence of hypomagnesemia and hypocalcemia in horses with surgical colic. 35 horses with surgically managed colic. Serum concentrations of total magnesium (tMg2+) and calcium (tCa2+), as well as ionized magnesium (iMg2+) and calcium (iCa2+) were analyzed before surgery and 1, 3, 5, and 7 days following surgery. A lead-II ECG and pertinent clinical data were also obtained at each time. Preoperative serum tMg2+ and iMg2+ concentrations were below the reference range in 6 (17%) and 19 (54%) horses, respectively. Serum concentrations of tCa2+ and iCa2+ were less than the reference range in 20 (57%) and 30 (86%) horses before surgery. Horses with strangulating lesions of the gastrointestinal tract had significantly lower preoperative serum concentrations of iMg2+ and iCa2+, as well as a higher heart rate than horses with nonstrangulating lesions. Horses that developed postoperative ileus had significantly lower serum concentrations of iMg2+ after surgery. Serum concentrations of magnesium and calcium (total and ionized) correlated significantly with the PR, QRS, QT, and corrected QT (QTc) intervals. Horses that were euthanatized at the time of surgery (n = 7) had significantly lower preoperative serum concentrations of iMg2+, compared with horses that survived. Neither serum magnesium nor calcium concentrations were predictors of hospitalization time or survival. Hypomagnesemia and hypocalcemia were common during the perioperative period, particularly in horses with strangulating intestinal lesions and ileus. Serum concentrations of tMg2+ and tCa2+ were less sensitive than iMg2+ and iCa2+ in detecting horses with hypomagnesemia and hypocalcemia.

Surgical treatment for colic in the foal (67 cases): 1980-1992.

Sixty-seven foals age < 150 days underwent a ventral celiotomy for colic. Of the 67 foals, 51 foals (82%) recovered from anaesthesia and 42 (63%) were subsequently released from the hospital. Three (6%) of the 51 foals were subjected to a repeat celiotomy. Long term follow-up was available on 36 foals. Twenty-nine (57%) of the 51 foals recovered from anaesthesia, were alive at least 2 years following surgery. Adhesions were identified in 8 (17%) of the foals which recovered from general anaesthesia but were subsequently subjected to euthanasia due to recurrent colic. Strangulating lesions were associated with a lower survival rate. Nineteen per cent of foals with strangulating intestinal lesions survived > 2 years following surgery, compared to 69% of foals with nonstrangulating lesions. The age of foals on admission had a significant effect on survival. Only 10% of foals less than 14 days of age survived, compared to 45.8% of foals between age 15 and 150 days.