Valutazione emodinamica con eco-doppler della vena porta in cani sani prima e dopo sedazione o anestesia

Doppler ultrasonography of portal vein is an useful and effective technique for evaluating hepatic portal hemodynamics and to detect vascular anomalies. Modification of velocity, portal flow, portal luminal diameter, porta-aorta ratio, can help to diagnosticate portosystemic shunts, chronic or congenital diseases , these can cause portal hypertension. Knowledge of the normal values for such variables is essential to recognize alterations that may occur in hepatic disease. In this study we adquire doppler flow measurements from the right intra-hepatic branch of the portal vein, in which smaller insonation angles can be more easily obtained. This in order to see values for mean velocity,flow volume and portal congestion index in healthy dog before and after the somministration of sedative/anesthetic. The 16 dogs of different sex and body weights obtained from the Veterinary Hospital, college of veterinary medicine ,Messina and a clinic in Palermo, were considered healthy based on physical,hematogical and biochemical analyses. Dogs were deprived of food for 12 hours and were administrated sedative and /or anesthetic substanced for diagnosic or chirurgical procedures. The animal were divided into 2 groups based on the protocol utilized: Group A: 11 dogs (9 females, 2 males) from 3,8 to 26 kilos . We gave Acepromazine : 0,5mg/kg IM and Propofol: 4 mg/kg IV. Group B: 5 dogs ( females ) from 5 to 22,9 Kilos we gave tiletamine-zolazepam 5mg/kg IM. The dogs were kept in left lateral decubitus position and the trasducer was placed on the right lateral body wall approximately on the last intercostal space. We measured the diameter and area of portal vein. From first plane the transducer was angled cranially so that the portal vein could be followed to the point that a longitudinal image of the right portal branch appared so we did doppler evaluation. The values we mesured were: portal diameter, portal area, mean velocity, congestion index (CI: te ratio between the portal area and mean velocity), portal blood flow volume (PBFV). For the statistical analyse we used software STATA with F-test. Group A Portal diameter (cm) Portal area (cm2) Vmean (cm/sec) CI (cmsec) PBFV (ml/min/kg) Pre O,72±0,16 0,45±0,16 12,12±2,99 0,03±0,01 31,80±12,57 Post 0,70±0,15 0,40± 0,16 12,17±3,46 0,03±0,01 27,72±11,48 Group B Portal diameter (cm) Portal area (cm2) Vmean (cm/sec) CI (cmsec) PBFV (ml/min/kg) Pre 0.84 ±0.08 0.50±0.12 11.11±2.98 0.046±0.20 25.82 ± 8.56 Post 0.79 ±0.22 0.47 ±0.27 10.26±3.58 0.04±0.01 20.36 ± 8.77 In both Groups A l the measurement had not significant change between the 2 exams. Other studies demonstrate that induction of ansethesia with propofol decrease arterial blood flow pressure ,whereas systemic vascular resistance is significally lowered but no significative changes in portal venous blood flow are noted. Acepromazina has an ipotensive action ( periferic vasodilation) and lower afterload. There aren’t academic work about the effects of the assotiation between Acepromazine and propofol . Tiletamine-zolazepam cause significant increases in heart rate and cardiac output, and cause decreases in arterial blood pressure; increase transiently peripheral vascular resistance but there are not study about th effects on the portal system. The limit of this study was the little sample of dogs , but we saw that the two protocols have no hemodinamic on the portal vein measurements. Should analized more subjects to demonstrate the effective inactivity of these drugs on portal vascular and flow.