Experimental evaluation of central venous pressure monitoring in the dog

The measurement of central venous pressure (CVP) will provide objective information about intravascular blood volume. Limitations exist with direct and indirect methods of measuring CVP; however, the purpose of this study was to determine if such factors as catheter size, patient position, or measurements taken with either a water manometer or a strain-gauge transducer would affect the accuracy of CVP measurements. The study population consisted of six adult, mixed-breed dogs. Catheter sizes evaluated were 16- and 19-gauge. Patient positions evaluated were right and left lateral recumbencies. Right atrial pressures (RAPs) were used as the reference standards for CVP measurements. Measurements of RAP and CVP were obtained with a water manometer and a strain-gauge transducer. No significant differences were observed in measured CVPs for the effects of catheter size and right versus left lateral recumbency. A 2.7-mmHg difference in water manometry was demonstrated when compared to strain-gauge transducer measurements. Also, strain-gauge transducer measurements had less precision compared to water manometer measurements.</jats:p

Cyanosis and congenital methemoglobinemia in a puppy

A six-month-old Pomeranian was referred for evaluation of cyanosis. The puppy had been cyanotic since it was acquired at six weeks of age, but otherwise appeared normal. Diagnostics were aimed at the most common causes (i.e., congenital defects in the cardiovascular and respiratory systems) of cyanosis in a juvenile animal. No clinically significant abnormalities were detected on evaluation of thoracic radiographs, echocardiogram, cardiac color-flow Doppler examination, or blood gases. At this point, a dysfunction in hemoglobin was considered as a possibility. Methemoglobinemia due to deficiency of methemoglobin reductase enzyme was diagnosed based on a specific assay.</jats:p