Biochemical, electrolytic, and cardiovascular evaluations in cats with urethral obstruction

Abstract

Background and Aim: Urethral obstruction (UO) is a common condition in feline medicine. Severe acid-base and electrolyte disorders promote relevant electrocardiographic changes in these animals. Cardiac biomarkers such as cardiac troponin I have been shown to be useful in identifying cats with myocardial disease, but it has not been investigated whether UO leads to myocardial damages. This study aimed to evaluate biochemical changes, electrocardiographic findings, troponin I measurements, and electrolyte disturbances for 7 days in cats with UO. Materials and Methods: This follow-up prospective study included 33 cats diagnosed with UO for 7 days. For all cats, clinical examination, serum biochemistry, electrolyte analyses, blood pressure, and electrocardiography were performed. Cardiac troponin I was measured in the serum in 16 cats at 3 different times. Results: The mean age of the feline population was 1.83±1.58 years (mean±standard deviation). Creatinine, urea, blood urea nitrogen, glucose, phosphorus, base excess, bicarbonate, and serum potassium decreased significantly (p≤0.05), while ionic calcium and blood pH increased significantly (p≤0.05) at different times. Electrocardiographic abnormalities were observed in 21/33 (63.63%) of the felines on admission day. The electrocardiographic abnormalities were no longer observed on the subsequent days. Only one feline showed changes in troponin I cardiac concentrations. Conclusion: This study suggests the sum and severity of electrolyte abnormalities aggravate the clinical and cardiovascular status of these patients. However, cTnI, blood pressure, and heart rate within the reference range do not exclude the presence of major cardiovascular and metabolic abnormalities. The hyperglycemia in felines with UO appears to be associated with decreased renal clearance, which may reflect the severity of hyperkalemia and azotemia. The metabolic and cardiovascular changes of these felines are minimized by the establishment of appropriate intensive care; however, cardiac and blood gas monitoring is essential to assess the severity of the disease.

Electrocardiographic changes associated with hyperkalaemia in domestic cats

“…8). Ventricular tachycardia in hyperkalaemia was previously reported by Tag and Day (2008) and Canei et al (2021). As the serum potassium concentration increased, there was a depression of the sino-atrial node, which results in a junctional or ventricular rhythm.…”

Symmetric dimethylarginine correlates with the urea, creatinine, potassium, and clinical scores in feline urethral obstructions

“…Hyperkalemia may be significant in cases of UO because of metabolic acidosis and tissue catabolism [ 21 ]. As previously suggested, the severity of electrolyte abnormalities aggravates the patient's clinical status [ 28 ]. The present study observed a moderate positive correlation between the clinical score and hyperkalemia.…”

“…A UO may lead to metabolic acidosis caused by the retention of metabolic acids, HCO 3 − consumption to stabilize the plasma pH, production of lactate associated with hypovolemia, hypoxia, and reduction in HCO 3 − tubular conservation during the post-obstructive period [ 21 28 ]. Therefore, the lack of correlation between the HCO 3 − and SDMA values may be explained, in part, by the distinct mechanisms through which these two biomarkers change during renal dysfunction.…”

“…This is because the mean values of HCO 3 − at this stage fell below the reference interval. This presentation can be justified by the functional renal impairment at the time of animal inclusion and its impact on the body’s acid-base balance [ 21 28 ]. Moreover, HCO 3 − reduction was not verified, possibly due to the institution of Ringer Lactate Solution in the clinical treatment of the cats.…”

Manejo anestésico de felino obstruido: Reporte de caso

“…Em casos mais graves, pode ocorrer instabilidade cardiovascular e azotemia. Vale ressaltar a importância da atenção à bradiarritmia causada pela hipercalemia, o que caracteriza esse paciente como um caso emergencial que requer atendimento imediato (Canei et al, 2021).…”