Small Animal Surgical Emergencies. Группа авторов
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Название: Small Animal Surgical Emergencies
Автор: Группа авторов
Издательство: John Wiley & Sons Limited
Жанр: Биология
isbn: 9781119658627
isbn:
Figure 9.1 Diagram of the visceral branches of the aorta with their principal anastomoses, ventral aspect.
Source: H Evans and A de Lahunta (eds.) [2]. Reproduced with permission from Elsevier.
Figure 9.2 Intraoperative photograph illustrating the classic appearance of intestinal volvulus. Note the obvious diffuse necrosis and distension of the bowel.
Diagnostics
Clinical pathological findings in patients with intestinal volvulus tend to be non‐specific. Normal to low packed cell volumes and plasma total solids are typical. White blood cell counts are normal to elevated. Serum chemistries are often normal or have non‐specific changes associated with gastrointestinal disease [6, 9, 18]. Given the similarities in the pathophysiology of the disease process with other conditions causing vascular compromise (such as gastric dilatation and volvulus), hypokalemia with metabolic acidosis and elevated serum lactate level would be anticipated. The only reported blood gas in a case of intestinal volvulus [10] revealed a metabolic alkalosis in a pattern similar to that seen with gastrointestinal foreign bodies [10,24–26]. Coagulation profiles have not been reported in the literature associated with this disease.
Figure 9.3 Decision‐making algorithm for a patient with an acute abdomen.
A three‐year‐old male, neutered Great Dane was evaluated for a 24‐hour history of vomiting, diarrhea, inappetence, and lethargy. A physical examination was unremarkable. The owners elected symptomatic therapy and monitoring, including fasting and subcutaneous fluids, with a plan for recheck if vomiting and diarrhea persisted. Less than 12 hours later, lethargy and inappetence persisted, and the dog was reevaluated. At repeat presentation, the dog appeared dehydrated and painful during abdominal palpation. A tubular structure was palpated in the dorsal mid‐abdomen. Mucoid stool was noted on rectal examination. Abdominal radiographs were taken, and a small bowel obstructive pattern was seen with severe intestinal distension noted (Case Figure 9.1a). Abdominal exploration was recommended. Preoperative bloodwork revealed a mild metabolic acidosis. The remaining complete blood count and serum chemistry were unremarkable. At the time of surgery, the small bowel appeared cyanotic and an intestinal volvulus was identified and corrected. At the time of correction, the bowel appeared normal and viable. A prophylactic gastropexy was performed and the dog was recovered from anesthesia. The dog made an uneventful recovery other than a mild incisional infection that resolved with antibiotic therapy. Three years later, the dog was presented for evaluation of vomiting, diarrhea, inappetence, and lethargy of 12 hours' duration. On physical examination, the dog appeared dehydrated and was tachycardic. Gas distended loops of bowel and a possible mass in the left lateral mid‐abdomen were palpated. The abdomen did not seem painful. Abdominal radiographs were taken (Case Figure 9.1b,c), and marked gas and fluid distension of the bowel was noted. Intestinal volvulus was suspected. Given the prognosis associated with the disease and the dog's history prompting suspicion for recurrence, the owner requested humane euthanasia. Necropsy was declined.
Case Figure 9.1 Lateral abdominal radiograph of a Great Dane with severe, generalized distension of the intestines. Abdominal exploratory surgery was performed and an intestinal volvulus was identified and corrected (a). Three years later, the dog presented because of vomiting, diarrhea, inappetence, and lethargy of 12 hours duration. Two abdominal images were taken because of the large size of the dog (b and c). Marked gas and fluid distension of the bowel was noted. A recurrence of intestinal volvulus was suspected.
Abdominal radiographs are the most practically useful non‐invasive diagnostic tool aiding the diagnosis of intestinal volvulus. Patients typically have severe, prominent gaseous small bowel distension and may have loss of serosal detail (see Case Figure 9.1a). The distended bowel loops may lie parallel to each other and resemble a paralytic ileus [3, 6, 18, 20]. The stomach as well as the descending colon are often not dilated. Abdominal ultrasonography in humans has revealed a characteristic barberpole or whirlpool sign with mesenteric torsion, as the bowel loops encircle the mesenteric vasculature. [27, 28]. Similarly, computed tomography in humans demonstrates a characteristic “whirl sign”, which has also been reported in dogs [22, 29]. Definitive diagnosis is achieved at the time of abdominal exploration or necropsy.
Treatment
Preoperative Treatment
Initial therapy is aimed at stabilizing the patient in hypovolemic shock, with emphasis placed on preparing the patient for correction of the intestinal and vascular anatomic abnormalities as promptly as possible. Fluid resuscitation is vital and should be among the first steps in treating patients; it should not be sacrificed in the pursuit of diagnostics. While septic and toxic shock will not resolve without management of the underlying cause, resuscitative efforts are employed to optimize patient status in preparation for anesthesia and surgery (see Chapter 1). Colloids or hypertonic crystalloids are used as necessary to correct hypotension. Once the patient is as stable as possible and a high index of suspicion for intestinal volvulus has been reached, abdominal exploration should not be delayed. Timeliness in correcting the volvulus is critical in influencing patient outcome [9, 20]. Anesthesia should be planned carefully as patients often remain critical at the time of surgery and may decompensate rapidly secondary to reperfusion injury or uncorrected acid–base abnormalities. Vasopressor therapy may be required to maintain normotension and protect renal function. If the patient is not responding to typical resuscitative efforts, and the index of suspicion for intestinal volvulus is high, rapid diagnostic and therapeutic decision making is critical. Typically, abdominal radiographs lead most efficiently to the diagnosis, however, to prevent further patient decompensation, clinical judgment must be exercised when deciding to take the time to obtain radiographs.
Surgical Treatment
Abdominal exploration allows for definitive diagnosis and assessment of the extent of disease while at the same time providing opportunity for correction. Characteristically, deep purple to black intestine is noted wherever vasculature is compromised. Compromised blood flow through the cranial mesenteric artery СКАЧАТЬ