Gastric Dilatation-volvulus: Lactate Clearance and Prognosis

Gastric dilatation-volvulus is an acute life-threatening condition that primarily affects large-breed dogs. By definition, the initiating event of the syndrome involves an abnormal entrapment and accumulation of fluid and air within the gastric lumen that results in extreme, traumatic distention of the stomach (dilatation) and variable rotation of the stomach on its long axis (volvulus). Early clinical signs (discomfort, pacing, panting, drooling, retching, and abdominal distention) are indicative of the initial events. However, the pathogenesis of GDV involves a more complex progression of physiologic disturbances that can rapidly (within hours) culminate in death unless immediate medical and surgical treatment is provided. Increased intragastric pressure obstructs blood flow in the caudal vena cava and portal vein, which results in decreased venous return and cardiac output (ie, obstructive shock). Although compensatory mechanisms are activated initially to maintain arterial pressure, corrective measures must be taken or inadequate tissue perfusion will progress and compromise organ function. Eventually, the shock will become refractory, multiple organs will fail, and death will be imminent. Even with intensive treatment, including presurgical stabilization, surgery, and postsurgical care, mortality rates for dogs with GDV range from 13% to 43%. To lower morbidity and mortality rates, a clear understanding of the progression of a disease is required and the ability to accurately assess and address factors most critical to survival is needed. Ideally, prognostic factors can be identified to assess critical components in the progression of disease, which can then be used to guide alternative or aggressive treatment strategies when appropriate. In numerous studies, investigators have identified prognostic indicators with regard to death of dogs with GDV. However, many of these indicators are of limited utility with regard to improving morbidity and mortality rates because they do not have alternative treatment strategies (eg, gastric necrosis, partial gastrectomy, and combined splenectomy and partial gastrectomy) or are complications that develop later in the course of the disease and alternative treatment strategies are limited (eg, peritonitis, sepsis, and disseminated intravascular coagulation). Early recognition and treatment are often required to prevent a disease from developing and acquiring severity. Risk factors for the likelihood of dying as a result of GDV that can be evaluated early in the course of the condition (eg, prior to surgical intervention) have been identified and include clinical status at time of admission, duration of clinical signs, and a single pretreatment plasma lactate concentration. Dogs that have signs of depression 10or that are comatose at admission are 3 or 36 times as likely to die, respectively. In 1 study, dogs with clinical signs for 5 hours prior to examination at a veterinary hospital had a mortality rate of 46%, whereas in another study, dogs with clinical signs for > 6 hours prior to examination at a veterinary hospital were significantly more likely to die. An initial plasma lactate concentration < 6 mmol/L has been reported to be associated with a survival rate of 99% in dogs with GDV,