THE INFLUENCE OF PATENT ARTERIAL DUCT LIGATION ON SELECTED CARDIOVASCULAR PARAMETERS AND THE APPEARANCE OF BRANHAM'S SIGN

Otvoreni arterijski vod (lat. patent ductus arteriosus, PDA) jedna je od najčešćih urođenih srčanih grešaka koja se javlja u 1 od 1000 pasa. Nastane ako izostane zatvaranje fiziološki prisutnog arterijskog voda nakon rođenja što rezultira brojnim kliničkim znakovima. Liječenje se u pasa provodi zatvaranjem voda arterijskim okluzijskim uređajima ili kirurškim podvezivanjem. Kao posljedica zatvaranja dolazi do razvoja krvožilnih promjena kao što su promjena tlaka, osobito dijastoličkog, i posljedičnog pada srčane frekvencije (Branhamov znak). Retrospektivnim istraživanjem analizirane su kliničke kartice i anesteziološki protokoli u šesnaest pasa u razdoblju od šest i pol godina. U premedikaciji je korištena kombinacija opioida i midazolama, indukcija je provedena propofolom ili etomidatom. Životinje su održavane u inhalacijskoj anesteziji sevofluranom. Analgezija za vrijeme zahvata osigurana je međurebrenim blokom 0,5% bupivakainom ili 2% lidokainom te kontinuiranom infuzijom fentanila i lidokaina (engl. constant rate infusion, CRI) po potrebi. U slučaju hipotenzije apliciran je CRI noradrenalina. Branhamov znak javio se u 63% pacijenata i bio je povezan s porastom dijastoličkog tlaka nakon kirurškog podvezivanja. Uspješnost podvezivanja PDA, bez zaostajanja rezidualnog protoka, u pasa s izraženim Branhamovim znakom, iznosila je 87,5%. U 75% pacijenata došlo je do samostalne rezolucije bradikardije i stabilizacije krvožilnih parametara. Smrtnost zahvata iznosila je 6%, a nastala je zbog intraoperativne rupture voda.Patent arterial duct (PDA) is one of the most common congenital heart defects that affects 1 in 1,000 dogs. It occurs when the closure of the physiologically present arterial duct is absent after birth, resulting in several clinical signs. Treatment in dogs is performed by closing the duct with arterial occlusive devices or surgical ligation. The closure results in the development of cardiovascular changes, for instance, vascular pressure changes, especially diastolic pressure and consequent drop in heart rate (Branham's sign). We analyzed clinical data and anesthetic protocols in a retrospective study in 16 dogs that were treated during a period of six and a half years. A combination of opioids and midazolam was used in premedication and general anesthesia was induced with propofol or etomidate. For maintenance of general anesthesia inhalant anesthetic sevoflurane was used. During the procedure, analgesia was secured with intercostal blocks (0.5% bupivacaine or 2% lidocaine) and constant rate infusion (CRI) of fentanyl and lidocaine as needed. In cases of hypotension, CRI of norepinephrine was initiated. Branham's sign occurred in 63% of patients and was associated with an increase in diastolic pressure after surgical ligation. The procedure was successful in 87,5% of the patients with Branham´s sign, who had no residual blood flow. In 75% of the patients, there was a self-contained resolution of bradycardia and stabilization of cardiovascular parameters. Mortality associated with the procedure was 6% and it was caused by intraoperative rupture of the arterial duct