The Case: Twisted Gastric Dilatation-Volvulus
PresentationA 12-year-old neutered male standard poodle was presented for abdominal discomfort/distention. Patient had history of hypoadrenocorticism (Addison’s disease) and was being treated by referring veterinarian with desoxycorticosterone pivalate (2.2 mg/kg IM every 25 days), last administered 2 weeks ago, and prednisone (0.02 mg/kg PO q12h).
Related Article: Acute Gastric Dilatation-Volvulus in Dogs
Examination/Diagnostics
Heart rate: 160 bpm
Capillary refill time: 3 sec
Radiography: Right lateral abdominal radiograph confirmed gastric dilatation/volvulus
Treatment
Stomach decompressed (18-gauge needle inserted on left side); air was released
Fluids: Plasmalyte 148 (500 mL/hr) for maintenance
Dexamethasone (0.25 mg/kg q12h)
Anesthesia: butorphanol (0.4 mg/kg); glycopyrrolate (0.003 mg/kg IV); propofol (7.7 mg/kg total to effect)
Intubated and stomach tube passed easily. Liquid kibble and gas retrieved; flushed with 40 L water until liquid was running clear.
Repeat radiograph showed stomach normal in size and position.
Postoperative Treatment/Monitoring
Butorphanol (0.2 mg/kg) upon recovery
Sodium/potassium ratio: 41:1
Serum biochemical analysis: within normal limits, except for total protein (51 g/L, range 52–82)
Fluids: reduced to 100 mL/hr
Dog was monitored overnight. Seemed comfortable; no further abdominal distention. Heart rate and electrocardiogram were within normal limits. Patient developed bloody diarrhea overnight. Owners had decided to pursue gastropexy the following morning.
Gastropexy
Fluids: Plasmalyte 148 @ 100 mL/hr
Cefazolin (22 mg/kg IV)
Anesthesia: Induced with butorphanol (0.4 mg/kg IV) and propofol to effect. Maintained during surgery on morphine/lidocaine/ketamine (90 mL/hr CRI; 4 mL [15 mg/kg] morphine, 25 mL [2 mg/mL] lidocaine, 0.6 mL [100 mg/mL] ketamine––all in a 500-mL bag of Plasmalyte 148); isoflurane inhalant 2%.
Surgical Procedure: Routine incision. Moderate amount of free bloody fluid in abdomen; stomach moderately distended. Decompressed with 16-gauge catheter and passed stomach tube. Marked amounts of brown/green fluid poured from nose, mouth, and tube. Lowered dog’s head to promote drainage. Stomach in normal position; liver/spleen/small intestine appeared normal. Routine gastropexy to right body wall performed; incision made into stomach and along body wall near ribs 11/12 for fixation of stomach; then closed with simple continuous sutures using 2-0 monocryl. Abdomen lavaged with 2 L warmed saline/removed with suction; no active bleeding. Routine abdominal closure using 0 monocryl in simple continuous pattern for linea alba, 2-0 for subcutaneous tissue, staples for skin.
Related Article: Belt-Loop Gastropexy for Gastric Dilatation Volvulus
Postsurgical Treatment/Monitoring
Morphine/lidocaine/ketamine cocktail reduced to 60 mL/hr
Plasmalyte 148 (40 mL/hr)
Cefazolin (22 mg/kg IV q8h)
Famotidine (1 mg/kg IV q12h)
Metoclopramide (0.01 mg/kg/hr CRI)
Recovery was slow; dog remained in lateral recumbency with head positioned to promote continued drainage of regurgitated fluids.
At 2 hours
Packed cell volume: 55%
Total protein: 50 (range, 52–82)
Potassium: 3.3 mmol/L (range, 3.5–5.8)
Sodium/potassium ratio: 48:1
At 4 hours, patient was still extremely sedate; constant dripping of brownish fluid through nose.
Capillary refill time: 2 sec
Heart rate: 160 bpm
No pulse deficits
At 4 ½ hours, dog experienced respiratory arrest. Cardiopulmonary resuscitation was started, patient was intubated, and 2 doses of epinephrine (0.1 mg/kg) given. Ventricular fibrillation was treated with a lidocaine bolus (2 mg/kg) to convert to ventricular tachycardia (continuous ventricular premature contraction).
OutcomeSecond lidocaine bolus did not convert heart rhythm and asystole occurred a few minutes later. Further resuscitative measures were unsuccessful; and the patient succumbed.
The Generalist’s OpinionBarak Benaryeh, DVM, DABVP
The clinician did an excellent job in decompressing the stomach quickly and providing fluid support. Gastric dilatation volvulus, however, carries a significant number of complications that can remain unseen and undiagnosed. It’s unstated why the decision was made to postpone surgery in this case: There is no way to assess the level of ischemia to portions of the stomach wall or spleen without exploratory surgery. Volvulus can lead to avulsions in the short gastric branches of the splenic artery. In addition, the spleen itself can be affected and portions devitalized. Decompressing the stomach provides immediate relief and can be lifesaving, but the appropriate next step should always be exploratory surgery. Even if the stomach returns to a normal position, such as happened in this case, there is no other way to assess what damage may have already occurred. Even a radiograph showing normal positioning of the stomach does not rule out what could now be a 360-degree torsion.
Serum Lactate as an IndicatorBlood analysis was not obtained until the morning after presentation. In any case of suspect GDV, a complete blood count, serum biochemical profile and, if available, a lactate level should be obtained at the outset. There is some debate as to how to assign weight to the initial lactate reading. Traditionally levels above 6.0 mmol/L have been associated with increased mortality; however, but some recent studies have called this figure into question. We do know that measuring changes in lactate helps to predict prognosis and guide aggressiveness of care.1,2
Preventing AspirationDuring the surgery on this dog, it appears that material was regurgitated or vomited around the tube. An appropriately sized endotracheal tube and absolute certainty that the cuff is fully inflated are both important considerations in any procedure in which a stomach tube will be passed. A very small amount of sterile lubricant applied to the cuff of the endotracheal tube also helps to ensure a complete seal. Regurgitation or vomiting is common in these cases, so taking all precautions to prevent aspiration is a vital step.
The outcome of this case was unfortunate. The take-home points include a necessity for surgical intervention, appropriate laboratory work, and precautions during surgery to minimize possible aspiration. Gastric dilatation-volvulus carries a high mortality rate relative to other emergency conditions and, even in the best of circumstances, can end tragically.
1. Evaluation of initial plasma lactate values as a predictor of gastric necrosis and initial and subsequent plasma lactate values as a predictor of survival in dogs with gastric dilatation-volvulus: 84 dogs (2003-2007). Green TI, Tonazzi CC, Kirby R, Rudloff E. J Vet Emerg Crit Care 21:36-44, 2011.
2. Association between outcome and changes in plasma lactate concentration during presurgical treatment in dogs with gastric dilatation-volvulus: 64 cases (2002-2008). Zacher LA, Berg J, Shaw SP, Kudej R. JAVMA 236:892-897, 2010.
Barak Benaryeh, DVM, DABVP, is the owner of Spicewood Springs Animal Hospital. He graduated from University of California–Davis School of Veterinary Medicine in 1997 and completed an internship in Small Animal Medicine, Surgery, and Emergency at University of Pennsylvania. Dr. Benaryeh has also taught practical coursework to first-year veterinary students and was a primary veterinary surgeon for the Helping Hands Program, which trains assistance monkeys for quadriplegic people. Dr. Benaryeh is certified by the American Board of Veterinary Practitioners in Canine and Feline Practice.
The Specialist’s OpinionElisa M. Mazzaferro, MS, DVM, PhD, DACVECC
This effort was a really good one in what sounds like a bad situation from the start. For example, it was a good indicator that the stomach was in its normal anatomic position following the orogastric lavage, and I love that the dog was monitored overnight with electrocardiography. There are a few parameters that were not mentioned in the case report: the dog's weight, how long the abdomen had been distended, and the duration of the signs of GDV. These have an important influence on management and prognosis.
Comments About MonitoringWhile I agree that it is important to consider the dog’s Addison's disease, I do not think that the electrolytes would have acutely decompensated with a hypoadrenocortical crisis, especially if the dog was receiving desoxycorticosterone pivalate. Thus, the sodium and potassium ratios are interesting, but we are missing a more important component in the description of the case monitoring and management, namely perfusion, perfusion, perfusion. Did you perform a lactate at the time of presentation? A number of manuscripts have shown that elevated lactate values that do not decrease by 40% to 50% after fluid resuscitation are a poor prognostic indicator.
You did not mention pulse quality or blood pressure. With a heart rate of 180 bpm and a capillary refill time (CRT) of 3 seconds, I'd bet that this dog was in decompensatory shock. What were the dog's heart rate and CRT after the fluid bolus? Were they becoming more normal? Were there any ventricular dysrhythmias in the immediate period following initial presentation or during surgery for gastropexy?
You stated that at the time of surgery the stomach was moderately distended, but did not mention its color and whether the tissue appeared viable. This observation is important because the stomach, with its potential for necrosis, is a potent stimulator for systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). If there were areas of the stomach that were marginally viable or questionable, I would recommend removing those areas (not invaginating). Based on the dog's initial clinical presentation, there is a good chance that it was experiencing SIRS.
The ongoing tachycardia raises the issues of poor vasodilation and cardiac contractility, which are both characteristic of SIRS. You mention that there were no pulse deficits, but don't mention ECG data until the dog arrested. Were there any problems of this nature?
Another thought is that the dog could have aspirated some stomach content and had fulminant aspiration pneumonia: Monitoring the end-tidal CO2 levels intraoperatively to assess whether the patient was ventilating properly and monitoring pulse oximetry to determine level of oxygenation would have been useful. The brownish fluid from the nose makes me very concerned about aspiration pneumonia, or possibly disseminated intravascular coagulation (DIC). Monitoring coagulation parameters is important in these patients.
I am obviously critiquing your case with the benefit of hindsight, and perhaps some of this monitoring was performed but not mentioned in the case write-up.
Comments About TreatmentIn face of the Addison’s disease, additional physiologic doses of glucocorticosteroids may have been necessary simply because the dog was stressed. Your choice of dexamethasone was a good one, particularly because of the dose level the dog needed. Having said that, it is important to remember that dexamethasone is fully 6 to 7 times as potent as prednisone. Thus, when calculating a physiologic dose, one needs to remember to divide the prednisone dose (0.25 mg/kg) by 6 or 7 to get the dose in milligrams of dexamethasone. Failing to do so is probably one of the most common drug errors that I see in clinical practice.
Current recommendations for doses of epinephrine based on the RECOVER consensus statements that were published recently in the Journal of Veterinary Emergency and Critical Care are 0.01 mg/kg every 3 to 5 minutes. If an animal is in ventricular fibrillation, the current recommendation is to electrically defibrillate whenever possible. If an electrical defibrillator is not available, the chemical defibrillator of choice is amiodarone, as it has been shown to be superior to lidocaine in pulseless ventricular tachycardia and ventricular fibrillation.
Combining a colloid such as hydroxyethyl starch (5–10 mL/kg IV bolus) with the crystalloid may have decreased the total volume required for fluid resuscitation. Dilutional coagulopathies are common with extreme crystalloid boluses. I titrate my fluids to a specific blood pressure and heart rate rather than arbitrarily starting with a specific volume per hour. Perhaps 500 mL/hour is this patient's "shock volume" of fluids, but again, it is difficult to tell without knowing the dog's weight. I think that the mildly decreased total protein was likely secondary to the dilutional effects of the crystalloid fluids.
Finally, whenever a patient with GDV comes in, I personally think the worst. Even if the stomach can be decompressed and returned to its normal anatomic position, I recommend immediate surgery, as more than 80% of such patients will develop a retwist in the near future.
My RecommendationsCareful monitoring of perfusion parameters, including blood lactate, heart rate, blood pressure, and capillary refill time on a continuous basis is very important in patients with GDV. I recommend Kirby's Rule of Twenty for monitoring these and patients in critical condition:
1. Fluid balance2. Oncotic pull3. Glucose4. Electrolytes and acid–base (calcium, potassium, sodium chloride, magnesium, and I might add lactate in here too for lack of a better place to put it)5. Oxygenation and ventilation6. Level of consciousness/mentation7. Blood pressure8. Heart rate, rhythm, and contractility9. Albumin10. Coagulation11. Red blood cell and hemoglobin concentration12. Renal function and urine output13. Immune function, WBC count, antibiotic dose and selection14. GI function and motility15. Drug doses and metabolism16. Nutrition17. Pain control18. Nursing care and patient mobilization19. Wound and catheter/bandage care20. Tender loving care
These 20 areas need to be considered in every case, even if you don't measure them moment to moment. Doing so keeps me thinking and often helps to keep my thoughts organized. In conclusion, in a severe case of GDV, I recommend the following:
Titrate IV crystalloids with colloids to a specific blood pressure rather than a specific volume. Use care to avoid hemodilution, which can contribute to a coagulopathy.
Pay attention to perfusion, perfusion perfusion. Monitor blood pressure and blood lactate in addition to pulse quality and CRT. Lactate values that aren't dropping in the face of adequate fluid resuscitation are a bad prognostic indicator.
Monitor your coagulation panels.
Take ’em to surgery, even if the stomach looks as though it is in its normal anatomic position on radiographs. I have seen a number of 360-degree torsions that look like simple dilated stomachs.
Assess viability of the stomach as soon as possible after a GDV and remove any questionably nonviable tissue at surgery.
Physiologic doses of steroids are important in hypoadrenocorticism patients. Use care not to oversupplement and calculate the "prednisone equivalent" doses of dexamethasone.
The RECOVER project is a great resource for the latest information on a consensus of CPR in small animals.
I am sorry for the loss of your patient and commend you for asking for a critical evaluation of your treatment of this case. I hope this information helps! GDV is one of my favorite emergency challenges. The critical ones can humble us many, many times despite our best efforts.
Elisa M. Mazzaferro, MS, DVM, PhD, DACVECC, is director of emergency services for Wheat Ridge Veterinary Specialists in Wheat Ridge, Colorado. She chairs the scientific program committee for the Veterinary Emergency and Critical Care Society (VECCS) and the Denver Area Veterinary Medical Society and is the interactive laboratory coordinator for the American Veterinary Medical Association’s annual convention. Dr. Mazzaferro is an active lecturer at national and international veterinary meetings. She has authored numerous peer-reviewed manuscripts, book chapters, and textbooks on the subjects of veterinary emergency and critical care.