Preoperative thoracic radiographic findings in dogs presenting for gastric dilatation-volvulus (2000-2010): 101 cases

Early career clinicians euthanize more dogs with nontraumatic hemoabdomen but not gastric dilatation and volvulus than more experienced clinicians

OBJECTIVE

To determine if clinician experience influenced the euthanasia rate in 2 common surgical emergencies.

ANIMALS

142 dogs with nontraumatic hemoabdomen (NTH) due to suspected ruptured splenic mass and 99 dogs with gastric dilatation-volvulus (GDV) where the owner either elected surgery or euthanasia.

PROCEDURES

Medical records were reviewed for dogs that had either NTH or GDV. For each patient, the owner's decision to pursue euthanasia versus surgery was recorded. The primary clinician was categorized as an intern, defined as a clinician with < 12 months experience, or a non-intern, defined as a clinician with more than 12 months experience. The euthanasia rates were compared used a Fisher exact, and the 95% CI was calculated for the risk of euthanasia if the primary clinician was an intern compared with a non-intern. If a difference was identified, subgroups comparing time of day, referral status, age, Hct, total solids, lactate, and heart rate were evaluated using a t test with a Bonferroni correction for the continuous variables and a Fisher exact for categorical variables.

RESULTS

For dogs with NTH, the euthanasia rate for cases primarily managed by non-interns (52%) was significantly lower than that of interns (76%; P = .005). The relative risk of euthanasia associated with NTH when the case was treated by an intern was 1.44 with a 95% CI of 1.1229 to 1.8567. For 99 dogs with GDV, the rate of euthanasia was not different between interns and non-interns.

CLINICAL RELEVANCE

The euthanasia rate for dogs with NTH may be impacted by the level of experience of the clinician. Support of new clinicians during challenging conversations should be provided.

Evaluation of a novel technique involving ultrasound-guided, temporary, percutaneous gastropexy and gastrostomy catheter placement for providing sustained gastric decompression in dogs with gastric dilatation-volvulus

OBJECTIVE

To evaluate the feasibility of ultrasound-guided, temporary, percutaneous T-fastener gastropexy (TG) and gastrostomy catheter (GC) placement for providing sustained gastric decompression in dogs with acute gastric dilatation-volvulus (GDV) and to compare findings with those of trocarization.

ANIMALS

16 dogs with GDV.

PROCEDURES

Dogs were randomly assigned to undergo gastric decompression by means of percutaneous trocarization (trocar group; n = 8) or temporary TG and GC placement (TTG+GC group; 8) with ultrasound guidance. The gastric volvulus was then surgically corrected, and the decompression sites were examined. Outcomes were compared between groups.

RESULTS

The proportion of dogs with successful decompression did not differ significantly between the TTG+GC (6/8) and trocar (7/8) groups; median procedure duration was 3.3 and 3.7 minutes, respectively. After the failed attempts in the TTG+GC group, the procedure was modified to include ultrasound guidance during T-fastener placement. The decrease in intragastric pressure by 5 minutes after trocar or GC insertion was similar between groups. For dogs in the TTG+GC group, no significant difference in intragastric pressure was identified between 5 and 60 minutes after GC insertion. Complications included inadvertent splenic or jejunal placement in 2 dogs (TTG+GC group) and malpositioned and ineffective trocar placement in 1 dog (trocar group). All dogs survived for at least 2 weeks.

CONCLUSIONS AND CLINICAL RELEVANCE

Ultrasound-guided, temporary, percutaneous TG and GC placement was safe and effective at providing sustained gastric decompression in dogs with GDV, suggesting that this technique would be ideal for dogs in which surgical delays are anticipated or unavoidable.

Acid-Base, Electrolyte and Lactate Abnormalities as Well as Gastric Necrosis and Survival in Dogs With Gastric Dilation-Volvulus Syndrome. A Retrospective Study in 75 Dogs

Gastric dilation-volvulus (GDV) syndrome in dogs is associated with complex metabolic, acid-base, and electrolyte abnormalities. The aim of this study was to evaluate previously analyzed factors (lactate and BE) in combination with other acid-base parameters (pH, pCO₂, bicarbonate, base excess [BE], anion gap [AG], and strong ion difference) and electrolyte concentrations and to evaluate their association with the incidence of gastric necrosis and outcome in dogs with GDV. A retrospective study in 75 dogs with gastric dilation-volvulus syndrome, University veterinary teaching hospital. Medical records were reviewed including signalment, history, initial plasma lactate, acid-base parameters, and electrolyte concentrations, surgical findings and outcome. The overall mortality was 18.7%. In dogs with gastric necrosis, higher initial plasma lactate (median 5.84 vs. 3.36 mmol/L) and AG (20.7 vs. 16.55 mmol/L) and lower pH (7.29 vs. 7.36), bicarbonate (18.7 vs. 22.9 mmol/L), and BE concentration (-8.1 vs. -1.85 mmol/L) were found compared to dogs without gastric necrosis. Anorganic phosphorus was the only electrolyte investigated for which a significant difference was noted between dogs with and without gastric necrosis (1.93 vs. 1.39 mmol/L). The initial plasma lactate concentration (3.36 mmol/L vs. 9.68 mmol/L) and AG (16.8 vs. 20.95 mmol/L) were lower in survivors than nonsurvivors. Survivors had higher pH (7.35 vs. 7.27), bicarbonate concentrations (22.9 vs. 17.35 mmol/L), and BE (-1.9 vs. -9.55 mmol/L) compared to nonsurvivors. Anorganic phosphorus was ultimately the only electrolyte with a significant difference between survivors and nonsurvivors (1.4 vs. 1.84 mmol/L). A multivariate logistic regression model of combination lactate, pH, bicarbonate, BE, AG, and anorganic phosphorus identified pH ≤7.331 and bicarbonate as factors independently associated with gastric necrosis. Similarly, pH ˃7.331, bicarbonate and anorganic phosphorus were independently associated with outcome. Higher initial plasma lactate, AG and anorganic phosphorus levels, and lower pH, BE and bicarbonate concentrations were found in GDV dogs with gastric necrosis. Similarly, initially higher plasma lactate, AG and anorganic phosphorus concentrations, and lower pH, BE and bicarbonate were found in GDV dogs who required euthanasia or who died after surgery. Of these parameters, pH and bicarbonate were strongly and independently associated with gastric necrosis, and pH, bicarbonate and phosphorus were independently associated with outcome.

Laparoscopic repositioning of chronic gastric volvulus in a dog

A 12-year-old spayed Newfoundland bitch was presented with chronic non-productive vomiting, regurgitation and coughing of six weeks' duration. On clinical examination, the dog was depressed with no other significant findings. Haematology and biochemistry investigations detected no abnormalities. Thoracic and abdominal radiographs revealed a megaoesophagus and an abnormally positioned pylorus. A thoracic and abdominal computed tomography scan confirmed the abnormal position of the stomach, together with moderate aspiration pneumonia. Laparoscopic examination of the peritoneal cavity revealed the greater omentum wrapped over the stomach, with a fold visualised between the abnormally positioned pyloric antrum and the gastric corpus. A 180-degree clockwise gastric rotation was laparoscopically diagnosed and corrected. The normal position of the stomach was confirmed before a laparoscopic-assisted incisional gastropexy was performed. Post-operatively the vomiting and regurgitation resolved and the patient was discharged. Twenty-four hours after discharge, the dog was presented with deteriorating clinical signs of aspiration pneumonia. The owner declined treatment, additional diagnostics as well as a necropsy and requested euthanasia. Chronic gastric volvulus should be considered as a rare differential diagnosis in dogs with non-specific, chronic gastrointestinal signs. Radiography, computed tomography and laparoscopy are valuable diagnostic aids in making this diagnosis. Chronic gastric volvulus can be successfully reduced laparoscopically as reported here for the first time.

Clinical use of plasma lactate concentration. Part 2: Prognostic and diagnostic utility and the clinical management of hyperlactatemia

OBJECTIVE

To review the current literature pertaining to the use of lactate as a prognostic indicator and therapeutic guide, the utility of measuring lactate concentrations in body fluids other than blood or plasma, and the clinical management of hyperlactatemia in dogs, cats, and horses.

DATA SOURCES

Articles were retrieved without date restrictions primarily via PubMed, Scopus, and CAB Abstracts as well as by manual selection.

HUMAN AND VETERINARY DATA SYNTHESIS

Increased plasma lactate concentrations are associated with increased morbidity and mortality. In populations with high mortality, hyperlactatemia is moderately predictive in identifying nonsurvivors. Importantly, eulactatemia predicts survival better than hyperlactatemia predicts death. Consecutive lactate measurements and calculated relative measures appear to outperform single measurements. The use of lactate as a therapeutic guide has shown promising results in people but is relatively uninvestigated in veterinary species. Increased lactate concentrations in body fluids other than blood should raise the index of suspicion for septic or malignant processes. Management of hyperlactatemia should target the underlying cause.

CONCLUSION

Lactate is a valuable triage and risk stratification tool that can be used to separate patients into higher and lower risk categories. The utility of lactate concentration as a therapeutic target and the measurement of lactate in body fluids shows promise but requires further research.

Assessment of the Prevalence of Gastric “Gravel Sign” in Dogs with Acute Gastric Dilatation-Volvulus

Radiological examination of gastric “gravel sign” was retrospectively conducted in 60 dogs presented with acute gastric dilatation-volvulus (GDV) syndrome. Other radiographic findings including loss of peritoneal serosal detail, presence of radiopaque foreign bodies, gastric pneumatosis, splenomegaly, and megaesophagus, were also examined in these patients. “Gravel sign” was detected on the pre-operative radiographs of 17 dogs with acute GDV (28.3%), suggesting that these patients could be suffering from chronic partial gastric obstruction before examination. German Shepherd dogs were significantly over-represented in this group (10/17, 58.8%). Dogs with acute GDV showing “gravel sign” should be carefully investigated for the presence of underlying gastrointestinal processes that might be associated with chronic partial obstruction.

Spontaneous gastric dilatation-volvulus in two cats

OBJECTIVES

To describe 2 cases of gastric dilatation-volvulus (GDV) in cats. To describe 2 unique clinical settings in which the disease occurs in cats, and to highlight the differences between GDV in cats and dogs.

CASE SERIES SUMMARY

Two neutered female Persian cats were presented for evaluation of respiratory distress. Initial physical examination revealed tachypnea, dyspnea, and a markedly distended and painful abdomen in both cats. Radiographs revealed a gas-dilated stomach and gastrointestinal (GI) tract in both cats but were only diagnostic for GDV in 1 case. Gastric dilatation-volvulus was confirmed during exploratory laparotomy and gastropexy was performed in each case. Both cats were successfully discharged from the hospital.

NEW AND UNIQUE INFORMATION PROVIDED

Gastric dilatation-volvulus in cats is a rare event and appears to occur in 2 clinical settings: in combination with traumatic diaphragmatic hernia (as previously reported) and without a history of trauma or diaphragmatic hernia, as in the 2 cases reported here. Clinicians should consider GDV in the list of differentials for cats with respiratory distress and abdominal distension, even if classic radiographic findings are not present.

Evaluation of thoracic radiographs as a screening test for dogs and cats admitted to a tertiary-care veterinary hospital for noncardiopulmonary disease

Thoracic radiographs are used as a screening tool for dogs and cats with a variety of disorders that have no clinical signs associated with thoracic structures. However, this practice has never been supported by an evidence-based study. The objective of this retrospective observational study was to determine if certain canine and feline populations have a higher proportion of radiographic abnormalities, and whether any of these abnormalities are associated with patient hospitalization and outcome. Patients were excluded if current or previous examinations revealed evidence of primary respiratory or cardiac disease, malignant neoplasia, or an abnormal breathing pattern consistent with pulmonary pathology. Any notable thoracic change in the radiology report was considered important and evaluated in this study. One hundred and sixty-six of these included patients were dogs and 65 were cats. Of the 166 dog radiographs evaluated, 120 (72.3%) had normal thoracic radiographs, while 46 (27.7%) had radiographic abnormalities. Of the sixty-five cats included, 36 (55.4%) had normal radiographs, while 29 (44.6%) had abnormal radiographs. Canine patients with abnormal radiographs had a significantly higher lactate level (P-value 0.0348) and feline patients with abnormal radiographs had a significantly lower packed cell volume (P-value 0.012). A large proportion of patients that had screening thoracic radiographs (32.5%) had documented abnormalities, but a relatively low percentage (6.5%) of our total population had their clinical plan changed as a consequence of detection of these abnormalities. Findings indicated that abnormal screening thoracic radiographs are more likely in dogs with an elevated lactate and cats with anemia, or a low normal hematocrit.

Cardiovascular and systemic effects of gastric dilatation and volvulus in dogs

Gastric dilatation and volvulus (GDV) is a common emergency condition in large and giant breed dogs that is associated with high morbidity and mortality. Dogs with GDV classically fulfill the criteria for the systemic inflammatory response syndrome (SIRS) and can go on to develop multiple organ dysfunction syndrome (MODS). Previously reported organ dysfunctions in dogs with GDV include cardiovascular, respiratory, gastrointestinal, coagulation and renal dysfunction. Cardiovascular manifestations of GDV include shock, cardiac arrhythmias and myocardial dysfunction. Respiratory dysfunction is also multifactorial, with contributory factors including decreased respiratory excursion due to gastric dilatation, decreased pulmonary perfusion and aspiration pneumonia. Gastrointestinal dysfunction includes gastric necrosis and post-operative gastrointestinal upset such as regurgitation, vomiting, and ileus. Coagulation dysfunction is another common feature of MODS in dogs with GDV. Disseminated intravascular coagulation can occur, putting them at risk of complications associated with thrombosis in the early hypercoagulable state and hemorrhage in the subsequent hypocoagulable state. Acute kidney injury, acid-base and electrolyte disturbances are also reported in dogs with GDV. Understanding the potential for systemic effects of GDV allows the clinician to monitor patients astutely and detect such complications early, facilitating early intervention to maximize the chance of successful management.