THE EFFECT OF DEXMEDETOMIDINE ON RADIOGRAPHIC CARDIAC SILHOUETTE SIZE IN HEALTHY CATS.

Dexmedetomidine, an alpha2 -adrenergic agonist, may be used in companion animals for chemical restraint, including cardiac evaluation. Echocardiographic changes associated with alpha2 -adrenergic agonists have been described; however reports of radiographic changes in cats were not found at the time of this study. Aims of this observational, prospective, experimental study were to describe the effects of dexmedetomidine on the radiographic appearance of the cardiac silhouette in healthy, adult cats. Fourteen healthy adult cats received dexmedetomidine 40 mcg/kg IM. Right lateral, left lateral, ventrodorsal, and dorsoventral thoracic radiographs were obtained for each cat at three time points: presedation, intrasedation, and postsedation (≥ two hours after reversal with atipamezole). Radiographs were evaluated in a blinded, randomized fashion by two independent observers using the vertebral heart score on all four views, the number of intercostal spaces on lateral projections, and the percent width of thorax on ventrodorsal and dorsoventral projections. Median vertebral heart score on right lateral view was significantly increased intrasedation (median = 7.8; range = 7.25-8.25) compared to presedation (median = 7.5; range = 7-8 [P = 0.001]). Median percentage width was significantly higher intrasedation (70% on VD; range 65-80 [P = 0.001], and 75% on DV; range 65-80 [P = 0.006]) compared to presedation (65%; range 65-75 on both projections). Dexmedetomidine was associated with a small but significant increase in cardiac silhouette size on right lateral (vertebral heart score), ventrodorsal (percentage width), and dorsoventral (percentage width) radiographs in healthy adult cats. This effect should be taken into consideration for future interpretation of thoracic radiographs in dexmedetomidine-sedated cats.

Effects of dexmedetomidine and its reversal with atipamezole on echocardiographic measurements and circulating cardiac biomarker concentrations in normal cats.

OBJECTIVE: To investigate the effects of dexmedetomidine (DXM) and its subsequent reversal with atipamezole (APM) on the echocardiogram and circulating concentrations of cardiac biomarkers in cats. ANIMALS: 14 healthy cats. PROCEDURES: Cats underwent echocardiography and measurements of circulating cTn-I and NT-proBNP concentrations before (PRE) and during (INTRA) DXM sedation (40 µg/kg IM) and 2 to 4 (2H POST) and 24 (24H POST) hours after reversal with APM. RESULTS: Administering DXM significantly decreased heart rate, right ventricular and left ventricular (LV) outflow tract velocities, and M-mode-derived LV free-wall thickness; increased LV end systolic diameter and volume; and caused valvar regurgitation. While sedative effects resolved within 25 minutes of APM reversal, the evolution of echocardiographic changes was mixed: LV ejection fraction and mitral valvar regurgitation score were different at 2H POST than at both INTRA and PRE (partial return toward baseline), LV end-diastolic volume was different PRE to INTRA and INTRA to 2H POST but not different PRE to 2H POST (full return toward baseline), and M-mode-derived LV free-wall thickness was significantly different from PRE to INTRA and PRE to 2H POST (no return toward baseline). Serum cTn-I and plasma NT-proBNP concentrations increased significantly with DXM, which remained significant 2H POST. CLINICAL RELEVANCE: Administration of DXM and APM reversal produced changes in echocardiographic results and in circulating cTn-I and NT-proBNP concentrations. Understanding these changes could help veterinarians differentiate drug effects from cardiac disease.

When staff meet Staph--MRSA in the hospital setting.

Occupational health nurses are in a position to counsel and educate health care personnel and to work as active partners with infection control teams. A basic understanding and awareness of MRSA can help reduce unnecessary costs to institutions, unnecessary loss of time, and hopefully, help decrease the rate of MRSA in hospital settings.