Small Animal Surgical Emergencies. Группа авторов

monitoring of vital parameters including heart rate, pulse quality, capillary refill time, mucous membrane color, and blood pressure is important to ensure patient stability. Failure of the patient to show clinical improvements postoperatively or worsening of clinical signs after a period of apparent improvement, should prompt further investigation as this may herald the onset of some complications. Tachycardia, bounding or weak pulses, prolonged capillary refill time, low central venous pressure, and low systemic blood pressure could indicate hypovolemia due to inadequate fluid replacement, losses through the GI tract, or losses due to SIRS‐induced vascular leak or low oncotic pressure. Sepsis‐induced vasodilation, as evidenced by hypotension and bright pink or red mucous membranes, may also contribute to similar cardiovascular abnormalities. Increases in respiratory rate or effort should prompt thorough auscultation followed by radiographs of the thorax, as these could be signs of aspiration pneumonia, acute respiratory distress syndrome, fluid overload, or systemic inflammatory response/hypoproteinemia‐induced hydrothorax. Development of a fever postoperatively may indicate development of pneumonia or septic peritonitis.

Figure 5.10 Small intestinal plication secondary to a linear foreign body in a cat.

Figure 5.11 Perforation of the small intestine at the mesenteric border, secondary to a linear foreign body in a cat.

      Healing of the GI tract occurs over several weeks to months, but the critical healing period is within the first three to five days postoperatively [63]. As such, postoperative gastrotomy, enterotomy, or resection and anastomosis patients should be monitored for evidence of dehiscence, particularly within the first five days. Fever, increasing volumes of peritoneal effusion, and increasing quantity of neutrophils or the presence of toxic neutrophils in the effusion are consistent with development of postoperative septic peritonitis and should prompt further investigation. Ultrasonography can be used to identify free fluid in the abdomen. Abdominocentesis, with or without the aid of ultrasound, should be taken to obtain a sample of abdominal fluid for biochemical evaluation and cytology (see Chapter 3, Video 3.1). Abnormal glucose and lactate ratios or the presence of bacteria in fluid taken directly from the abdomen (but not taken from a drain) are consistent with septic peritonitis [64]. However, incisional dehiscence rates following gastrotomy or enterotomy are relatively low. A study evaluating incisional dehiscence rates for 247 dogs undergoing enterotomy for GI foreign body removal found only a 2% dehiscence rate in these specific patients [65].

      The need for enteral nutrition should be taken into account at the time of surgery; and a surgically placed feeding tube should be strongly considered in animals with septic peritonitis, multiple GI incisions, resection and anastomosis, or those with preoperative hypoproteinemia. Early enteral nutrition is important to provide nutrients for repair and rapid return to function of the GI tract and is preferred over parenteral nutrition. Early enteral nutrition after colonic resection and anastomosis shortened time until return of GI motility and maintained nutritional status more effectively than total parenteral nutrition [66]. While controlling for other variables, in a study by Liu et al., dogs that received enteral or parenteral nutrition within 24 hours postoperatively had significantly shorter hospitalization length (by 1.6 days) compared with dogs that did not receive early nutrition [67]. Comparatively, dogs with septic peritonitis receiving any parenteral nutrition were significantly less likely to survive than dogs that did not receive parenteral nutrition and had a significantly longer hospitalization, although the dogs receiving parenteral nutrition may have been sicker than dogs able to be fed enterally [68].

      Choices of tube entry site include nasal, esophageal, or gastric. If the animal fails to eat shortly after surgery, a perioperatively placed feeding tube facilitates adequate nutrition without need for a second episode of general anesthesia specifically for tube placement. Current nutritional recommendations are to meet resting energy requirements, rather than applying an illness factor, as higher supplementation rates have been associated with higher complication rate and mortality [69, 70]. If unable to provide complete enteral feedings, provision of enteral glutamine, the energy source for enterocytes, may be beneficial. Glutamine can enhance the immune system, decrease bacterial translocation, increase mucous production [71], and as a supplement, glutamine has been shown to decrease morbidity in certain critically ill patient populations [72]. Dogs receiving glutamine after distal gastrectomy had a significantly shorter time to return of GI motility compared to placebo controls [69]. The published dose of glutamine is 0.5 g/kg/day divided into two to three doses [73, 74].

      Long‐Term Postoperative Complications

      A variety of long‐term postoperative complications have been reported. There are reports of foreign material caught on staples and polypropylene suture material that had extruded into the intestinal lumen at the sites of a previous enterotomy or resection and anastomosis [75, 76]. An obstructive mural intestinal abscess has been reported at an enterotomy site [77]. Foreign body penetration and intra‐abdominal abscess formation have also occurred at sites of enteroplication [78]. In patients with extensive bowel resection, management for short bowel syndrome may be necessary. Loss of the ileocecal valve may lead to reflux of colonic bacteria into the small intestine and subsequent development of diarrhea.

Prognosis

      Overall prognosis for dogs and cats with foreign bodies is good. In a review of 208 GI foreign bodies by Hayes, overall survival rate was 91%, with better survival being reported for pets with discrete foreign bodies (94% in dogs and 100% in cats) and than linear (80% in dogs and 63% in cats) foreign bodies [2]. A more recent study evaluating 499 dogs with linear and non‐linear GI foreign bodies found a 96% survival rate overall [55]. Other studies have reported survival rates for linear foreign bodies to be 78–98% in dogs [4, 11, 55] and 84–92% in cats [13, 79]. Increased mortality has also been reported for dogs with fabric and plastic linear foreign bodies [11], pets undergoing multiple GI incisions [2, 30], and those with longer duration of clinical signs (mean 4.6 ± 6.8 days vs. mean 8.7 ± 7.7 days) [4]. The presence of a foreign body for >3 days has also been associated with an increase in the rate of complications [21]. Location of the foreign body and degree of obstruction have not been shown to significantly influence survival [2].

6 Intussusception

       Janet Kovak McClaran1 and Yekaterina Buriko2

       1 London Vet Specialists, London, UK

       2 Veterinary Hospital of the University of Pennsylvania, Philadelphia, PA, USA

Introduction

      Intussusception of the digestive tract is the telescoping or invagination of a portion of the viscus into the lumen of an adjacent section of the tract. It occurs in both canine and feline patients. The portion that becomes entrapped is referred to as the intussusceptum, and the portion of bowel that receives the telescoping segment is known as the intussuscipiens. Intussusception may involve most parts of the digestive tract and has been documented to involve the esophagus, the stomach, and the intestinal tract. The most common type of intussusception has been reported as ileocolic [1, 2] in dogs and jejunojejunal in cats [3]. Double intussusception has been reported in dogs [4, 5]. Many conditions have been associated with intussusception, including motility dysfunction,